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Leslie Wilson,1 Douglas P Beall,2 Robert Kenneth Eastlack,3 Sigurd Berven,4 Jeffrey C Lotz4 1Department of Pharmacy, UC San Francisco, San Francisco, CA, 94143, USA; 2Comprehensive Specialty Care, Edmond, OK, 73034, USA; 3Department of Orthopaedic Surgery, Scripps Clinic, La Jolla, CA, 92037, USA; 4Department of Orthopaedic Surgery, UC San Francisco, San Francisco, CA, 94143-0728, USACorrespondence: Leslie Wilson, Department of Pharmacy, UC San Francisco, San Francisco, CA, 94143, USA, Tel +1 415-990-1012, Email leslie.wilson@ucsf.eduBackground/Context: Chronic low back pain (CLBP) is a significant US healthcare burden with millions of lumbar spine procedures annually. Diagnostic tests are essential to guide treatment but provocative discography (PD), the most common diagnostic procedure, is without robust evidence of its value. A non-invasive alternative using Magnetic Resonance Spectroscopy (MRS) offers a potential solution.Context/Purpose: We assess cost-effectiveness of MRS with NOCISCAN diagnostic algorithm compared to PD for identifying lumbar discs requiring surgical intervention.Study Design/Setting: We conducted cost-effectiveness analysis using modelling.Patient Sample: We used data from a clinical study of 139 CLBP patients who met criteria for and received PD of lumbar spine and presented with an ODI score ≥ 40; comparing PD and MRS-based diagnostics.Outcome Measures: We considered diagnostic costs, adverse events, surgical costs and outcomes based on a 15-point improvement on the Oswestry Disability Index.Methods: Incremental cost-effectiveness ratios (ICERS) and probabilistic sensitivity analyses were determined. Some authors have consulted for Aclarion.Results: Mean total cost per PD patient was $59,711, and $57,998 for MRS, demonstrating $1712 cost savings per MRS diagnosed patient. Diagnostic costs ($1950 for PD; $1450 for MRS), saved $500 per MRS patient. PD incurred adverse event costs ($57,323) for 1% of patients, which MRS eliminated. MRS-based diagnosis showed 78% surgical success, whereas PD achieved 68%. MRS was the dominant diagnostic strategy, with better clinical outcomes and cost savings. Probabilistic sensitivity analysis confirmed MRS dominance and was cost-effective across a wide range of willingness-to-pay thresholds and across 2 different scenarios which vary base-case outcomes and surgical rates.Conclusion: This study demonstrates cost-effectiveness dominance of MRS with the Nociscan diagnostic algorithm over PD for identifying CLBP surgical candidates. MRS provides significant cost savings and leads to better surgical outcomes, making it a preferred choice for insurers and health systems.Plain Language Summary: Chronic low back pain (cLBP) is experienced by 20% of the US population. It is difficult to determine the best treatment, and many have unnecessary surgery. Discography is the currently available diagnostic but is invasive, of limited value and with serious adverse events. MRS+Nociscan, a new non-invasive diagnostic uses MR Spectroscopy and an algorithm to identify painful discs, is FDA registered. Our aim is to conduct a cost-effectiveness analysis (CEA) to compare the economic value of these two diagnostic procedures. Subjects were part of a multicenter study of 139 patients who received MR imaging and PD for chronic low back pain. The intervertebral disc MRS data post-processing was performed using the NOCISCAN-LS software algorithm. We developed a decision tree model comparing provocative discogram (PD) with an MRS+ Nociscan diagnostic algorithm using a health system perspective over 12-months. The primary endpoint was surgical ODI success or failure. Costs were from the Medicare Fee Schedule. We calculated in incremental cost-effectiveness ratio (ICER), in terms of the additional cost or savings per additional treatment success gained. The mean total PD group cost per patient was $59,711 and $57,998 in the MRS+Nociscan group demonstrating that MRS-based diagnosis saved $1712 per patient diagnosed. Clinical success with MRS-based diagnosis was 78%, and 68% with PD diagnosis. The cost-effectiveness demonstrated strong MRS-Nociscan dominance, meaning it was both cost saving and a better clinical success. The strong cost-effectiveness dominance for MRS+Nociscan diagnosis answers the budgetary questions for insurers and health systems considering adoption of this new diagnostic tool.Keywords: cost, cost-effectiveness, lumbar spine, diagnostics, outcomes, discography

Background: Early-term complications may not predict long-term success after adult cervical deformity (ACD) correction., Objective: Evaluate whether optimal realignment results in similar rates of perioperative complications but achieves longer-term cost-utility., Study Design: Retrospective cohort study., Methods: ACD patients with 2-year data included. Outcomes: distal junctional failure (DJF), good clinical outcome (GCO):[Meeting 2 of 3: (1) NDI>20 or meeting MCID, (2) mJOA≥14, (3)NRS-Neck improved≥2]. Ideal Outcome defined as GCO without DJF or reoperation. Patient groups were stratified by correction to 'Optimal radiographic outcome', defined by cSVA 9 (<40 mm) AND TS-CL (<15 deg) upon correction. Cost calculated by CMS.com definitions, and cost-per-QALY was calculated by converting NDI to SF-6D. Multivariable analysis controlling for age, baseline T1-slope, cSVA, disability, and frailty, was used to assess complication rates, clinical outcomes, and cost-utility based on meeting optimal radiographic outcome., Results: One hundred forty-six patients included: 52 optimal radiographic realignment (O) and 94 not optimal (NO). NO group presented with higher cSVA and T1-slope. Adjusted analysis showed O group suffered similar 90-day complications (P>0.8), but less DJK, DJF (0% vs. 18%; P<0.001) and reoperations (18% vs. 35%; P=0.02). Patients meeting optimal radiographic criteria more often met Ideal outcome [odds ratio: 2.2, (1.1-4.8); P=0.03]. Despite no differences in overall cost, O group saw greater clinical improvement, translating to a better cost-utility [mean difference: $91,000, ($49,000-$132,000); P<0.001]., Conclusion: Despite similar perioperative courses, patients optimally realigned experienced less junctional failure, leading to better cost-utility compared with those sub-optimally realigned. Perioperative complication risk should not necessarily preclude optimal surgical intervention, and policy efforts might better focus on long-term outcome measures in adult cervical deformity surgery., Level of Evidence: Level III., Competing Interests: P.G.P. Allosource: Other financial or material support Cervical Scoliosis Research Society: Research support Globus Medical: Paid presenter or speaker Medtronic: Paid consultant Royal Biologics: Paid consultant Spine: Editorial or governing board SpineWave: Paid consultant Terumo: Paid consultant Zimmer: Paid presenter or speaker. V.L. DePuy, A Johnson & Johnson Company: Paid presenter or speaker European Spine Journal: Editorial or governing board Globus Medical: Paid consultant International Spine Study Group: Board or committee member Nuvasive: IP royalties Scoliosis Research Society: Board or committee member The Permanente Medical Group: Paid presenter or speaker. R.L. Nemaris: Stock or stock Options. R.K.E., MD Aesculap/B.Braun: Paid consultant Alphatec Spine: Stock or stock Options Baxter: Paid consultant Biedermann-Motech: Paid consultant Carevature: Paid consultant; Stock or stock Options Globus Medical: IP royalties Invuity: Stock or stock Options Medtronic: Paid consultant Nocimed: Stock or stock Options Nuvasive: IP royalties; Paid consultant; Research support; Stock or stock Options Radius: Paid presenter or speaker San Diego Spine Foundation: Board or committee member Scoliosis Research Society: Board or committee member Seaspine: IP royalties; Paid consultant; Stock or stock Options SI Bone: IP royalties; Paid consultant Society of Lateral Access Surgery: Board or committee member Spine Innovations: Stock or stock Options Stryker: Paid consultant. A.J.S. AAOS: Board or committee member Journal of Bone and Joint Surgery—American: Editorial or governing board North American Spine Society: Board or committee member Spine: Editorial or governing board Springer: Publishing royalties, financial or material support Wolters Kluwer Health—Lippincott Williams & Wilkins: Publishing royalties, financial or material support. L.A.T. Medtronic: Paid consultant Stryker: Paid consultant. T.B. ISSGF—Research support, NuVasive – Research support, Operative Neurosurgery— Editorial Board, Spine Deformity—Editorial Board. The remaining authors declare no conflict of interest., (Copyright © 2025 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To investigate the impact of the Global Alignment and Proportion (GAP) score components on patient outcomes in Adult Spine Deformity (ASD) surgery., Methods: Patients included underwent assessment via the GAP score and its individual components: pelvic version (GAP PV), lumbar lordosis (GAP LL), lumbar distribution index (GAP LDI) and spinopelvic component (GAP SP). Multivariable analyses assessed the association between alignment in these components and clinical outcomes in ASD patients., Results: 762 ASD patients met inclusion criteria. Alignment in GAP SP independently predicted meeting MCID for SR-22S and ODI and was associated with a lower likelihood of developing mechanical complications. Patients aligned in GAP SP were less likely to develop proximal junctional kyphosis (OR 0.42, 0.26-0.73, p = 0.01) and PJF (OR 0.3, 0.13-0.74, p = 0.01). Proportioned alignment in GAP SP with disproportioned alignment in GAP LDI contributed to an increased risk of PJK and PJF (OR 2.67, 95% CI 1.95-6.82, p = 0.045). There was no significant association of GAP SP proportionality and GAP RPV (OR 1.1, 0.86-2.15, p = 0.253) or GAP LL (OR 1.34, 0.78-4.23, p = 0.673) disproportionality with outcomes. Disproportioned alignment in GAP SP but proportioned alignment in both GAP LL and GAP LDI was associated with decreased likelihood of PJK (OR 0.53, 95% CI 0.39-0.94, p = 0.02) and PJF (OR 0.31, 95% CI 0.19-0.67, p = 0.001)., Conclusion: The spinopelvic component of the GAP score is the most significant independent predictor of clinical outcomes. Its interaction with the other components of the GAP score also aids assessment of the risk for mechanical complications., Competing Interests: Declarations. Conflicts of interest: None. Ethical approval: Institutional Review Board approval was obtained before enrolling patients in the prospective database. Informed consent was obtained from each patient prior to enrollment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background Context: While the treatment of adult spinal deformity (ASD) has increasingly favored surgical correction, the incidence of revision surgery remains high. Yet, little has been explored on the association between the etiology of reoperation and patient outcomes., Purpose: To assess the impact of the etiology of revision surgery on postoperative outcomes., Study Design/setting: Retrospective cohort analysis., Patient Sample: 891 ASD patients., Outcome Measures: Complications, radiographic parameters, disability metrics., Methods: Operative ASD patients with at least 1 revision stratified by etiology (mechanical [Mech] -pseudoarthrosis, thoracic decompensation without junctional failure, x-ray malalignment, implant failure, implant malposition, PJK ± major malalignment; infection [Infx]-early vs late onset, major vs minor; wound [Wound]; SI pain [SI Pain]). Excluded multiple etiologies, and intraoperative or medical complications. Data from the immediate visit prior to the final revision was used as baseline (rBL). Follow-up based on visits best aligned to time points after final revision. Radiographic parameters SVA, PI-LL, and PT were used to assess alignment post-revision via ANOVA. Multivariate analysis controlling for relevant covariates assessed outcome differences after final revision surgery., Results: 891 met inclusion (Age: 60.40±14.17, 77% F, BMI: 27.97±5.87 kg/m2, CCI: 1.80±1.73). Etiology groups were as follows: Mech: 432; Infx: 296; Wound: 65; SI Pain: 98. Surgically, Infx had lower rates of osteotomy, interbody fusion, and decompression (p<.05). Infx and SI Pain demonstrated similar correction in radiographics SVA, PI-LL, and PT (p>.05), whereas Mech had significantly less improvement by 2 years (p<.003) that improved by 5 years. Compared to without revision, the odds of MCID in ODI were 48.6% lower across groups (OR: 0.514 [.280, .945], p=.032). Indications of x-ray malalignment were 93.0% less likely to reach MCID (OR: 0.071, [.006, .866], p=.038). Similarly, implant failure negatively impacted rates of MCID (40% vs. 15.2%, p=.029). Those with PJK had 57% lower odds of MCID (33% vs 54%, OR: .43, [0.2, 0.9] p= .023), further negated by major malalignment (OR: 0.05, [.07, .97], p=.02). Indications of pseudarthrosis, thoracic decompensation, implant malposition were not significant. Major sepsis had lower rates of MCID compared to minor (6.4% vs. 21.2%), and early onset infection improved compared to late (OR: 1.43, [1.17, 2.98], p<.001). In the early follow-up period, the Mech group has significantly worse SRS Pain and Mental Health scores compared to other groups (1-year: Mech 1.56 vs Infx 0.83 vs SI Pain 0.72, p<.001; 2-year: 1.88 vs 0.71 vs 0.76, p=.034). Complication rates increased with the number of revisions and with mechanical indication (all p<.05). At 5 years, patient satisfaction was significantly more likely to improve compared to early follow-up (OR: 1.22, p=.011), along with improved pain score, in Mech group (0.89 vs 0.49 vs 0.56, p=.081)., Conclusions: This study focused on the impact of revision as it varies with etiology and time of occurrence postoperatively. Compared to other etiologies, revision surgery due to mechanical complications had less radiographic improvement and worsening patient-reported scores in the early postoperative period despite stabilization at 5 years. The depth of impact of mechanical complication, particularly with the addition of malalignment, merits greater focus during surgical planning., Level of Evidence: III., Competing Interests: Declaration of Competing Interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Our understanding of the relationship between sagittal alignment and mechanical complications is evolving. In normal spines, the L1-pelvic angle (L1PA) accounts for the magnitude and distribution of lordosis and is strongly associated with pelvic incidence (PI), and the T4-pelvic angle (T4PA) is within 4° of the L1PA. We aimed to examine the clinical implications of realignment to a normal L1PA and T4-L1PA mismatch., Methods: A prospective multicenter adult spinal deformity registry was queried for patients who underwent fixation from the T1-T5 region to the sacrum and had 2-year radiographic follow-up. Normal sagittal alignment was defined as previously described for normal spines: L1PA = PI × 0.5 - 21°, and T4-L1PA mismatch = 0°. Mechanical failure was defined as severe proximal junctional kyphosis (PJK), displaced rod fracture, or reoperation for junctional failure, pseudarthrosis, or rod fracture within 2 years. Multivariable nonlinear logistic regression was used to define target ranges for L1PA and T4-L1PA mismatch that minimized the risk of mechanical failure. The relationship between changes in T4PA and changes in global sagittal alignment according to the C2-pelvic angle (C2PA) was determined using linear regression. Lastly, multivariable regression was used to assess associations between initial postoperative C2PA and patient-reported outcomes at 1 year, adjusting for preoperative scores and age., Results: The median age of the 247 included patients was 64 years (interquartile range, 57 to 69 years), and 202 (82%) were female. Deviation from a normal L1PA or T4-L1PA mismatch in either direction was associated with a significantly higher risk of mechanical failure, independent of age. Risk was minimized with an L1PA of PI × 0.5 - (19° ± 2°) and T4-L1PA mismatch between -3° and +1°. Changes in T4PA and in C2PA at the time of final follow-up were strongly associated (r 2 = 0.96). Higher postoperative C2PA was independently associated with more disability, more pain, and worse self-image at 1 year., Conclusions: We defined sagittal alignment targets using L1PA (relative to PI) and the T4-L1PA mismatch, which are both directly modifiable during surgery. In patients undergoing long fusion to the sacrum, realignment based on these targets may lead to fewer mechanical failures., Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The International Spine Study Group (ISSG) is funded through research grants from NuVasive, SI-Bone, DePuy Synthes Spine, K2M, Stryker, Biomet, AlloSource, and Orthofix, and individual donations. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/I191 )., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Background and Objectives: For patients with surgical adult spinal deformity (ASD), our understanding of alignment has evolved, especially in the last 20 years. Determination of optimal restoration of alignment and spinal shape has been increasingly studied, yet the assessment of how these alignment schematics have incrementally added benefit to outcomes remains to be evaluated., Methods: Patients with ASD with baseline and 2-year were included, classified by 4 alignment measures: Scoliosis Research Society (SRS)-Schwab, Age-Adjusted, Roussouly, and Global Alignment and Proportion (GAP). The incremental benefits of alignment schemas were assessed in chronological order as our understanding of optimal alignment progressed. Alignment was considered improved from baseline based on SRS-Schwab 0 or decrease in severity, Age-Adjusted ideal match, Roussouly current (based on sacral slope) matching theoretical (pelvic incidence-based), and decrease in proportion. Patients separated into 4 first improving in SRS-Schwab at 2-year, second Schwab improvement and matching Age-Adjusted, third two prior with Roussouly, and fourth improvement in all four. Comparison was accomplished with means comparison tests and χ 2 analyses., Results: Sevenhundredthirty-two. patients met inclusion. SRS-Schwab BL: pelvic incidence-lumbar lordosis mismatch (++:32.9%), sagittal vertical axis (++: 23%), pelvic tilt (++:24.6%). 640 (87.4%) met criteria for first, 517 (70.6%) second, 176 (24%) third, and 55 (7.5%) fourth. The addition of Roussouly (third) resulted in lower rates of mechanical complications and proximal junctional kyphosis (48.3%) and higher rates of meeting minimal clinically important difference (MCID) for physical component summary and SRS-Mental ( P < .05) compared with the second. Fourth compared with the third had higher rates of MCID for ODI (44.2% vs third: 28.3%, P = .011) and SRS-Appearance (70.6% vs 44.8%, P < .001). Mechanical complications and proximal junctional kyphosis were lower with the addition of Roussouly ( P = .024), while the addition of GAP had higher rates of meeting MCID for SRS-22 Appearance ( P = .002) and Oswestry Disability Index ( P = .085)., Conclusion: Our evaluation of the incremental benefit that alignment schemas have provided in ASD corrective surgery suggests that the addition of Roussouly provided the greatest reduction in mechanical complications, while the incorporation of GAP provided the most significant improvement in patient-reported outcomes., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Background: Research has focused on the increased correction from a three-column osteotomy (3CO) during adult spinal deformity (ASD) surgery. However, an in-depth analysis on the performance of a 3CO in a cohort of complex spinal deformity cases has not been described., Study Design/setting: This is a retrospective study on a prospectively enrolled, complex ASD database., Purpose: This study aimed to determine if three-column osteotomies demonstrate superior benefit in correction of complex sagittal deformity at the cost of increased perioperative complications., Methods: Surgical complex adult spinal deformity patients were included and grouped into thoracolumbar 3COs compared to those who did not have a 3CO (No 3CO) (remaining cohort). Rigid deformity was defined as ΔLL less than 33% from standing to supine. Severe deformity was defined as global (SVA > 70 mm) or C7-PL > 70 mm, or lumbopelvic (PI-LL > 30°). Means comparison tests assessed correction by 3CO grade/location. Multivariate analysis controlling for baseline deformity evaluated outcomes up to six weeks compared to No 3CO., Results: 648 patients were included (Mean age 61 ± 14.6 years, BMI 27.55 ± 5.8 kg/m 2 , levels fused: 12.6 ± 3.8). 126 underwent 3CO, a 20% higher usage than historical cohorts. 3COs were older, frail, and more likely to undergo revision (OR 5.2, 95% CI [2.6-10.6]; p < .001). 3COs were more likely to present with both severe global/lumbopelvic deformity (OR 4), 62.4% being rigid. 3COs had greater use of secondary rods (OR 4st) and incurred 4 times greater risk for: massive blood loss (> 3500 mL), longer LOS, SICU admission, perioperative wound and spine-related complications, and neurologic complications when performed below L3. 3COs had similar HRQL benefit, but higher perioperative opioid use. Mean segmental correction increased by grade (G3-21; G4-24; G5-27) and was 4 × greater than low-grade osteotomies, especially below L3 (OR 12). 3COs achieved 2 × greater spinopelvic correction. Higher grades properly distributed lordosis 50% of the time except L5. Pelvic compensation and non-response were relieved more often with increasing grade, with greater correction in all lower extremity parameters (p < .01). Due to the increased rate of complications, 3COs trended toward higher perioperative cost ($42,806 vs. $40,046, p = .086)., Conclusion: Three-column osteotomy usage in contemporary complex spinal deformities is generally limited to more disabled individuals undergoing the most severe sagittal and coronal realignment procedures. While there is an increased perioperative cost and prolongation of length of stay with usage, these techniques represent the most powerful realignment techniques available with a dramatic impact on normalization at operative levels and reciprocal changes., (© 2024. The Author(s), under exclusive licence to Scoliosis Research Society.)

Study Design: Case-based survey., Objectives: This study aims to investigate what a group of surgeons learned from their own revisions, and what they would do differently today., Methods: A multi-center database of ASD surgical patients was queried to identify those with at least 2 surgical procedures performed by the same surgeon between 2009 and 2019. A clinical vignette was created for each case including demographics, a timeline of events, radiographs/measurements, patient-reported outcomes, complications, and surgical strategies used for the index and revision surgeries. The operative surgeon was then asked to fill out a five-question survey aimed at determining factors that contribute to operative decision-making and planning., Results: 86 patients were operated on by 6 participating surgeons for both index and revision ASD surgery. The revised patients had similar follow-up compared to the non-revised group ( P = 0.73), with the most common complications indicating a need for revision surgery being proximal junctional failure (42%) and pseudoarthrosis (28%). Surgeons reported that they would not change their surgical strategy in 52.3% of the cases. The leading cause for revision was hardware/instrumentation issues (24.4%). Learning points included rod-related choice (23.3%), level selection (19.8), PJF prophylactic strategy (15.1%), and sagittal alignment objective (11.6%)., Conclusions: Surgeons saw opportunity in nearly half of the cases to improve outcomes by changing something in the original surgery. While 40% of the failures remained unexplained from the surgeons' perspective, this study highlights the capacity for adopting changes in adult spinal deformity surgery and illuminates the reasoning behind certain surgical decisions., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: The aim of this study was to provide benchmarks for the rates of complications by type of surgery performed., Study Design: Prospective multicenter database., Background: We have previously examined overall construct survival and complication rates for ASD surgery. However, the relationship between type of surgery and construct survival warrants more detailed assessment., Materials and Methods: Eight surgical scenarios were defined based on the levels treated, previous fusion status [primary (P) vs. revision (R)], and three-column osteotomy use (3CO): short lumbar fusion, LT-pelvis with 5 to 12 levels treated (P, R, or 3CO), UT-pelvis with 13 levels treated (P, R, or 3CO), and thoracic to lumbar fusion without pelvic fixation, representing 92.4% of the case in the cohort. Complication rates for each type were calculated and Kaplan-Meier curves with multivariate Cox regression analysis was used to evaluate the effect of the case characteristics on construct survival rate, while controlling for patient profile., Results: A total of 1073 of 1494 patients eligible for 2-year follow-up (71.8%) were captured. Survival curves for major complications (with or without reoperation), while controlling for demographics differed significantly among surgical types ( P <0.001). Fusion procedures short of the pelvis had the best survival rate, while UT-pelvis with 3CO had the worst survival rate. Longer fusions and more invasive operations were associated with lower 2-year complication-free survival, however, there were no significant associations between type of surgery and renal, cardiac, infection, wound, gastrointestinal, pulmonary, implant malposition, or neurological complications (all P >0.5)., Conclusions: This study suggests that there is an inherent increased risk of complication for some types of ASD surgery independent of patient profile. The results of this paper can be used to produce a surgery-adjusted benchmark for ASD surgery with regard to complications and survival. Such a tool can have very impactful applications for surgical decision-making and more informed patient counseling., Level of Evidence: Level III., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Retrospective Cohort Study., Objectives: Length of Stay (LOS) and resource utilization are of primary importance for hospital administration. This study aimed to understand the incremental effect of having a specific complication on LOS among ASD patients., Methods: A retrospective examination of prospective multicenter data utilized patients without a complication prior to discharge to develop a patient-adjusted and surgery-adjusted predictive model of LOS among ASD patients. The model was later applied to patients with at least 1 complication prior to discharge to investigate incremental effect of each identified complication on LOS vs the expected LOS., Results: 571/1494 (38.2%) patients experienced at least 1 complication before discharge with a median LOS of 7 [IQR 5 to 9]. Univariate analysis demonstrated that LOS was significantly affected by patients' demographics (age, CCI, sex, disability, deformity) and surgical strategy (invasiveness, fusion length, posterior MIS fusion, direct decompression, osteotomy severity, IBF use, EBL, ASA, ICU stay, day between stages, Date of Sx). Using patients with at least 1 complication prior discharge and compared to the patient-and-surgery adjusted prediction, having a minor complication increased the expected LOS by 0.9 day(s), a major complication by 3.9 days, and a major complication with reoperation by 6.3 days., Conclusion: Complications following surgery for ASD correction have different, but predictable impact on LOS. Some complications requiring minimal intervention are associated with significant and substantial increases in LOS, while complications with significant impact on patient quality of life may have no influence on LOS., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study Design: Multicenter, prospective cohort., Objectives: Malalignment following adult spine deformity (ASD) surgery can impact outcomes and increase mechanical complications. We assess whether preoperative goals for sagittal alignment following ASD surgery are achieved., Methods: ASD patients were prospectively enrolled based on 3 criteria: deformity severity (PI-LL ≥25°, TPA ≥30°, SVA ≥15 cm, TCobb≥70° or TLCobb≥50°), procedure complexity (≥12 levels fused, 3-CO or ACR) and/or age (>65 and ≥7 levels fused). The surgeon documented sagittal alignment goals prior to surgery. Goals were compared with achieved alignment on first follow-up standing radiographs., Results: The 266 enrolled patients had a mean age of 61.0 years (SD = 14.6) and 68% were women. Mean instrumented levels was 13.6 (SD = 3.8), and 23.2% had a 3-CO. Mean (SD) offsets (achieved-goal) were: SVA = -8.5 mm (45.6 mm), PI-LL = -4.6° (14.6°), TK = 7.2° (14.7°), reflecting tendencies to undercorrect SVA and PI-LL and increase TK. Goals were achieved for SVA, PI-LL, and TK in 74.4%, 71.4%, and 68.8% of patients, respectively, and was achieved for all 3 parameters in 37.2% of patients. Three factors were independently associated with achievement of all 3 alignment goals: use of PACs/equivalent for surgical planning ( P < .001), lower baseline GCA ( P = .009), and surgery not including a 3-CO ( P = .037)., Conclusions: Surgeons failed to achieve goal alignment of each sagittal parameter in ∼25-30% of ASD patients. Goal alignment for all 3 parameters was only achieved in 37.2% of patients. Those at greatest risk were patients with more severe deformity. Advancements are needed to enable more consistent translation of preoperative alignment goals to the operating room., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: reports consultancy fees from ZimVie, NuVasive, Cerapedics, and Carlsmed; receives royalties from Zimmer Biomet and Nuvasive; holds stock in Alphatec and NuVasive; receives research funding to his institution from DePuy Synthes, International Spine Study Group Foundation (ISSGF), and AOSpine; receives fellowship grant funding to his institution from AOSpine; serves on the Executive Committee of the ISSGF; and serves on the editorial boards of Journal of Neurosurgery Spine, Neurosurgery, Operative Neurosurgery, and Spine Deformity. is a consultant for ISSGF. is a consultant for Globus Medical and Alphatec; receives royalties from NuVasive; receives research support from ISSG; receives honoraria from DePuy Synthes, Stryker, and Implanet; and has leadership roles in ISSG and the Scoliosis Research Society. is a consultant for DePuy Synthes, Stryker, and Medtronic, SI Bone, and Agnovos; receives honoraria and a fellowship grant paid to an institution from AO Spine; and has leadership roles with AOSpine. Dr. Kim receives royalties from Zimmer Biomet, Acuity Surgical, and K2M-Stryker; is a consultant for NuVasive; receives research support from the ISSGF; is on advisory boards for Vivex Biology and Aspen Medical; and has other financial or non-financial interests with AOSpine. is a consultant for Medtronic, SpineWave, Terumo, and Royal Biologics; receives honoraria from Cervical Spine Research Society, Globus Medical, and Zimmer; serves on the editorial or governing board for Spine journal; and receives research support from Allosource. receives research support from Stryker, Biom’Up, Pfizer, the Alan L. & Jacqueline B. Stuart Spine Center, National Health Foundation, Cerapedics, Empirical Spine, Inc., TSRH, and Scoliosis Research Society; receives royalties from Acuity, Medtronic, and NuVasive; is a consultant for Acuity, DePuy, Medtronic, NuVasive, FYR Medical, and Stryker; receives honoraria from Baxter, Broadwater, NASS, and Pacira Pharmaceuticals; holds patents with Medtronic; participates on a data safety monitoring board or advisory board with Medtronic; has a leadership role in the National Spine Health Foundation; owns stock/stock options in Cingulate Therapeutics and FYR Medical; is an employee of Norton Healthcare, Inc.; and serves as a journal reviewer for Global Spine Journal, Spine Deformity, and The Spine Journal. and receives research/fellowship support from NuVasive, Medtronic, SeaSpine, SI Bone, and AONA; receives royalties from SI Bone, Nuvasive, Seaspine, Aesculap, and Globus Medical; is a consultant for Aesculap, NuVasive, SI Bone, SeaSpine, Spinal Elements, Biedermann-Motech, Silony, Neo Medical, Depuy, Medtronic, Carevature, and ControlRad; has received payment/honoraria from Radius; has patents with Globus, Spine Innovation, and SI Bone; has leadership role with San Diego Spine Foundation; and has stock/stock options with Alphatec, Nuvasive, Seaspine, and SI Bone. receives grants/research support from Medtronic and Orthofix; receives royalties from Spineart and Stryker; is a consultant for Stryker Spine, Spineart, and Medtronic; and has received payment for expert testimony from multiple law firms. is a consultant for NuVasive, Viseon, Carlsmed, SI Bone, and SeaSpine; holds patents with Stryker, NuVasive, and SeaSpine; has leadership roles with Global Spine Outreach and San Diego Spine Foundation; has stock or stock options with Alphatec, SeaSpine, and NuVasive; and receives royalties from NuVasive and K2M/Stryker. is a consultant for Globus, NuVasive, and Medtronic; receives royalties from Altus; receives grants from Medtronic; and has stock or stock options from One Point Surgical. Dr. receives travel expenses to teach at the ISSG-Medtronic Spine Course for fellows and residents; and has a leadership role with the Canadian Spine Society. receives grants/research support from Prosydiuan and NuVasive. receives honoraria from Wolters Kluwer; received support for travel from AO Spine; has leadership roles with Scoliosis Research Society and AO Spine; and receives research support from the Setting Scoliosis Straight Foundation and San Diego Spine Foundation. is a consultant for Stryker Spine; receives grant/research support from Medtronic, DePuy Synthes, and AOSpine; receives honoraria from Medtronic, Stryker Spine, DePuy Synthes, Scoliosis Research Society, and AOSpine; receives support for travel from AO Spine and Scoliosis Research Society; and is on an advisory board/panel for AOSpine Research Commission and Scoliosis Research Society Research Task Force; and is Chair of the AO Spine Knowledge Forum Deformity. owns stock in J&J; is a consultant for DePuy, Medtronic, Globus; receives royalties from Innomed, DePuy, and Globus; receives honoraria from AO Spine, Wright State, and LSU; serves on the board of directors of the Scoliosis Research Society; receives travel reimbursements from DePuy, Globus, Scoliosis Research Society; and has a voluntary relationship with the National Spine Health Foundation. is a consultant for MSD, Zimmer Biomet, and Mainstay Medical; receives royalties from Zimmer Biomet, Medtronic, and Stryker; owns stock in VFT Solutions and SeaSpine; is an executive committee member of ISSG. receives royalties from DePuy Spine, Globus, and Blue Ocean Spine; is a consultant for DePuy Spine, Globus, and Blue Ocean Spine; has a leadership role in the Scoliosis Research Society and International Spine Study Group Foundation; has stock or stock options in Progenerative Medical; and has received research support from DePuy Spine and ISSGF. receives royalties from Stryker, Biomet Zimmer Spine, DePuy Synthes, NuVasive, Next Orthosurgical, K2M, and Medicrea; is a consultant for DePuy Synthes, Medtronic, Medicrea, K2M, Agada Medical, and Carlsmed; receives research support from Titan Spine, DePuy Synthes, and ISSG; serves on the editorial board of Operative Neurosurgery; receives grant funding from SRS; serves on the executive committee of ISSG; is the director of Global Spinal Analytics; and is the safety and value committee chair of SRS. is a consultant for Medtronic, ABRYX, and Acuity Surgical; receives research/grant support from AOSpine, Scoliosis Research Society, and Setting Scoliosis Straight Foundation; receives royalties from Medtronic and Acuity Surgical; and receives other financial support from Broadwater, AOSpine, and Scoliosis Research Society. is a consultant for NuVasive, SI Bone, and Proprio; owns stock in NuVasive; holds patents with NuVasive; receives fellowship funding from Globus, Medtronic, and NuVasive; and receives royalties from NuVasive, Medtronic, and SI Bone; has leadership roles with SRS and CSRS; and receives study-related clinical or research support from DePuy Synthes and ISSGF. is a consultant for Zimmer Biomet, NuVasive, Cerapedics, Carlsmed, SeaSpine, and DePuy Synthes; owns stock in Alphatec and NuVasive; receives study-related clinical or research support from DePuy Synthes and ISSGF; receives non–study-related clinical or research support from DePuy Synthes, ISSGF, and AO Spine; receives royalties from Zimmer Biomet and NuVasive; and receives fellowship support from AO Spine. is a consultant for Alphatec, Stryker, and MiRus; receives honoraria from Stryker; holds patents with Stryker; receives study-related clinical or research support from Medtronic, Globus, NuVasive, Stryker, Carlsmed, and SI Bone; receives non–study-related clinical or research support from DePuy Synthes; and receives royalties from Stryker and NuVasive. report no conflicts of interest.

Study Design: A retrospective cohort study of a prospectively collected multicenter adult spinal deformity (ASD) database., Objective: The aim of this study was to compare staged procedures to same-day interventions and identify the optimal time interval between staged surgeries for the treatment of ASD., Background: Surgical intervention for ASD is an invasive and complex procedure that surgeons often elect to perform on different days (staging). Yet, there remains a paucity of literature on the timing and effects of the interval between stages., Materials and Methods: ASD patients with 2-year data undergoing an anterior/posterior (A/P) fusion to the ilium were included. Propensity score matching was performed for the number of levels fused, number of interbody devices, surgical approaches, number of osteotomies/three-column osteotomy, frailty, Oswestry Disability Index, Charlson Comorbidity Index, revisions, sagittal vertical axis, pelvic incidence-lumbar lordosis, and upper instrumented vertebrae to create balanced cohorts of same-day and staged surgical patients. Staged patients were stratified by intervening time-period between surgeries, using quartiles., Results: A total of 176 propensity score-matched patients were included. The median interval between A/P staged procedures was 3 days. Staged patients had greater operative time and lower intensive care unit stays postoperatively ( P <0.05). At 2 years, staged compared with same-day showed a greater improvement in T1 slope-cervical lordosis, C2 sacral slope, and SRS-Schwab sagittal vertical axis ( P <0.05). Staged patients had higher rates of minimal clinically important difference for 1-year SRS-Appearance and 2-year Physical Component Summary scores. Assessing different intervals of staging, patients at the 75th percentile interval showed greater improvement in 1-year SRS-Pain and SRS-Total postoperative as well as SRS-Activity, Pain, Satisfaction, and Total scores ( P <0.05) compared with patients in lower quartiles. Compared with the 25th percentile, patients reaching the 50th percentile interval were associated with increased odds of improvement in Global Alignment and Proportion score proportionality [9.3 (1.6-53.2), P =0.01]., Conclusions: This investigation is among the first to compare multicenter staged and same-day surgery A/P ASD patients fused to ilium using propensity matching. Staged procedures resulted in significant improvement radiographically, reduced intensive care unit admissions, and superior patient-reported outcomes compared with same-day procedures. An interval of at least 3 days between staged procedures is associated with superior outcomes in terms of Global Alignment and Proportion score proportionality., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The optimal configuration for spinopelvic fixation during multilevel spine fusion surgery for adult spine deformity remains unclear. Postoperative sacroiliac (SI) joint pain, S2AI screw loosening and implant breakage could be related to continued motion of the SI joint with use of only a single point of fixation across the SI joint., Methods: Prospective, international, multicenter randomized controlled trial of 222 patients with adult spine deformity scheduled for multilevel (4 or more levels) spine fusion surgery with pelvic fixation. Subjects were randomized to sacroalar (S2) iliac (S2AI) screws alone for pelvic fixation or S2AI + triangular titanium implants placed cephalad to S2AI screws. Quad rod techniques were not allowed or used. Baseline spinal deformity measures were read by an independent radiologist. Site-reported perioperative adverse events were reviewed by a clinical events committee. Quality of life questionnaires and other clinical outcomes are in process with planned 2-year follow-up., Results: One hundred thirteen participants were assigned to S2AI and 109 to S2AI + titanium triangular implants (TTI). 35/222 (16%) of all subjects had a history of SI joint pain or were diagnosed with SI joint pain during preoperative workup. Three-month follow-up was available in all but 4 subjects. TTI placement was successful in 106 of 109 (98%) subjects assigned to TTI. In 2 cases, TTI could not be placed due to anatomical considerations. Three TTI ventral iliac breaches were observed, all of which were managed non-surgically. One TTI subject had a transverse sacral fracture and 1 TTI subject had malposition of the implant requiring removal., Conclusions: SI joint pain is common in patients with adult spinal deformity who are candidates for multilevel spine fusion surgery. Concurrent placement of TTI parallel to S2AI screws during multilevel spine fusion surgery is feasible and safe. Further follow-up will help to determine the clinical value of this approach to augment pelvic fixation., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Objective: Provide benchmarks for the rates of complications by type and timing., Study Design: Prospective multicenter database., Background: Complication rates following adult spinal deformity (ASD) surgery have been previously reported. However, the interplay between timing and complication type warrants further analysis., Methods: The data for this study were sourced from a prospective, multicenter ASD database. The date and type of complication were collected and classified into three severity groups (minor, major, and major leading to reoperation). Only complications occurring before the two-year visit were retained for analysis., Results: Of the 1260 patients eligible for two-year follow-up, 997 (79.1%) achieved two-year follow-up. The overall complication rate was 67.4% (N=672). 247 patients (24.8%) experienced at least one complication on the day of surgery (including intraoperatively), 359 (36.0%) between postoperative day 1 and six weeks postoperatively, 271 (27.2%) between six weeks and one-year postoperatively, and finally 162 (16.3%) between one year and two years postoperatively. Using Kaplan-Meier survival analysis, the rate of remaining complication-free was estimated at different time points for different severities and types of complications. Stratification by type of complication demonstrated that most of the medical complications occurred within the first 60 days. Surgical complications presented over two distinct timeframes. Operative complications, incision-related complications, and infections occurred early (within 60 d), while implant-related and radiographic complications occurred at a constant rate over the two-year follow-up period. Neurological complications had the highest occurrence within the first 60 days but continued to increase up to the two-year visit., Conclusion: Only one-third of ASD patients remained complication-free by two years, and 2 of 10 patients had a complication requiring a reoperation or revision. An estimation of the timing and type of complications associated with surgical treatment may prove useful for more meaningful patient counseling and aid in assessing the cost-effectiveness of treatment., Level of Evidence: 3., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background Context: Among adult spinal deformity (ASD) patients, heterogeneity in patient pathology, surgical expectations, baseline impairments, and frailty complicates comparisons in clinical outcomes and research. This study aims to qualitatively segment ASD patients using machine learning-based clustering on a large, multicenter, prospectively gathered ASD cohort., Purpose: To qualitatively segment adult spinal deformity patients using machine learning-based clustering on a large, multicenter, prospectively gathered cohort., Study Design/setting: Machine learning algorithm using patients from a prospective multicenter study and a validation cohort from a retrospective single center, single surgeon cohort with complete 2-year follow up., Patient Sample: About 805 ASD patients; 563 patients from a prospective multicenter study and 242 from a single center to be used as a validation cohort., Outcome Measures: To validate and extend the Ames-ISSG/ESSG classification using machine learning-based clustering analysis on a large, complex, multicenter, prospectively gathered ASD cohort., Methods: We analyzed a training cohort of 563 ASD patients from a prospective multicenter study and a validation cohort of 242 ASD patients from a retrospective single center/surgeon cohort with complete two-year patient-reported outcomes (PROs) and clinical/radiographic follow-up. Using k-means clustering, a machine learning algorithm, we clustered patients based on baseline PROs, Edmonton frailty, age, surgical history, and overall health. Baseline differences in clusters identified using the training cohort were assessed using Chi-Squared and ANOVA with pairwise comparisons. To evaluate the classification system's ability to discern postoperative trajectories, a second machine learning algorithm assigned the single-center/surgeon patients to the same 4 clusters, and we compared the clusters' two-year PROs and clinical outcomes., Results: K-means clustering revealed four distinct phenotypes from the multicenter training cohort based on age, frailty, and mental health: Old/Frail/Content (OFC, 27.7%), Old/Frail/Distressed (OFD, 33.2%), Old/Resilient/Content (ORC, 27.2%), and Young/Resilient/Content (YRC, 11.9%). OFC and OFD clusters had the highest frailty scores (OFC: 3.76, OFD: 4.72) and a higher proportion of patients with prior thoracolumbar fusion (OFC: 47.4%, OFD: 49.2%). ORC and YRC clusters exhibited lower frailty scores and fewest patients with prior thoracolumbar procedures (ORC: 2.10, 36.6%; YRC: 0.84, 19.4%). OFC had 69.9% of patients with global sagittal deformity and the highest T1PA (29.0), while YRC had 70.2% exhibiting coronal deformity, the highest mean coronal Cobb Angle (54.0), and the lowest T1PA (11.9). OFD and ORC had similar alignment phenotypes with intermediate values for Coronal Cobb Angle (OFD: 33.7; ORC: 40.0) and T1PA (OFD: 24.9; ORC: 24.6) between OFC (worst sagittal alignment) and YRC (worst coronal alignment). In the single surgeon validation cohort, the OFC cluster experienced the greatest increase in SRS Function scores (1.34 points, 95%CI 1.01-1.67) compared to OFD (0.5 points, 95%CI 0.245-0.755), ORC (0.7 points, 95%CI 0.415-0.985), and YRC (0.24 points, 95%CI -0.024-0.504) clusters. OFD cluster patients improved the least over 2 years. Multivariable Cox regression analysis demonstrated that the OFD cohort had significantly worse reoperation outcomes compared to other clusters (HR: 3.303, 95%CI: 1.085-8.390)., Conclusion: Machine-learning clustering found four different ASD patient qualitative phenotypes, defined by their age, frailty, physical functioning, and mental health upon presentation, which primarily determines their ability to improve their PROs following surgery. This reaffirms that these qualitative measures must be assessed in addition to the radiographic variables when counseling ASD patients regarding their expected surgical outcomes., Competing Interests: Declaration of Competing Interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Study Design: Retrospective review of a prospective multicenter adult spinal deformity (ASD) study., Objective: The aim of this study was to evaluate 30-day readmissions, 90-day return to surgery, postoperative complications, and patient-reported outcomes (PROs) for matched ASD patients receiving nonhome discharge (NON), including acute rehabilitation (REHAB), and skilled nursing facility (SNF), or home (HOME) discharge following ASD surgery., Summary of Background Data: Postoperative disposition following ASD surgery frequently involves nonhome discharge. Little data exists for longer term outcomes for ASD patients receiving nonhome discharge versus patients discharged to home., Materials and Methods: Surgically treated ASD patients prospectively enrolled into a multicenter study were assessed for NON or HOME disposition following hospital discharge. NON was further divided into REHAB or SNF. Propensity score matching was used to match for patient age, frailty, spine deformity, levels fused, and osteotomies performed at surgery. Thirty-day hospital readmissions, 90-day return to surgery, postoperative complications, and 1-year and minimum 2-year postoperative PROs were evaluated., Results: A total of 241 of 374 patients were eligible for the study. NON patients were identified and matched to HOME patients. Following matching, 158 patients remained for evaluation; NON and HOME had similar preoperative age, frailty, spine deformity magnitude, surgery performed, and duration of hospital stay ( P >0.05). Thirty-day readmissions, 90-day return to surgery, and postoperative complications were similar for NON versus HOME and similar for REHAB (N=64) versus SNF (N=42) versus HOME ( P >0.05). At 1-year and minimum 2-year follow-up, HOME demonstrated similar to better PRO scores including Oswestry Disability Index, Short-Form 36v2 questionnaire Mental Component Score and Physical Component Score, and Scoliosis Research Society scores versus NON, REHAB, and SNF ( P <0.05)., Conclusions: Acute needs must be considered following ASD surgery, however, matched analysis comparing 30-day hospital readmissions, 90-day return to surgery, postoperative complications, and PROs demonstrated minimal benefit for NON, REHAB, or SNF versus HOME at 1- and 2-year follow-up, questioning the risk and cost/benefits of routine use of nonhome discharge., Level of Evidence: Level III-prognostic., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To assess the financial impact of Enhanced Recovery After Surgery (ERAS) protocols and cost-effectiveness in cervical deformity corrective surgery., Study Design: Retrospective review of prospective CD database., Background: Enhanced Recovery After Surgery (ERAS) can help accelerate patient recovery and assist hospitals in maximizing the incentives of bundled payment models while maintaining high-quality patient care. However, the economic benefit of ERAS protocols, nor the heterogeneous components that make up such protocols, has not been established., Methods: Operative CD patients ≥18 y with complete pre-(BL) and up to 2-year(2Y) postop radiographic/HRQL data were stratified by enrollment in Standard-of-Care ERAS beginning in 2020. Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors, and complication rates were assessed through means comparison analysis. Costs were calculated using PearlDiver database estimates from Medicare pay scales. QALY was calculated using NDI mapped to SF6D using validated methodology with a 3% discount rate to account for a residual decline in life expectancy., Results: In all, 127 patients were included (59.07±11.16 y, 54% female, 29.08±6.43 kg/m 2 ) in the analysis. Of these patients, 54 (20.0%) received the ERAS protocol. Per cost analysis, ERAS+ patients reported a lower mean total 2Y cost of 35049 USD compared with ERAS- patients at 37553 ( P <0.001). Furthermore, ERAS+ patients demonstrated lower cost of reoperation by 2Y ( P <0.001). Controlling for age, surgical invasiveness, and deformity per BL TS-CL, ERAS+ patients below 70 years old were significantly more likely to achieve a cost-effective outcome by 2Y compared with their ERAS- counterparts (OR: 1.011 [1.001-1.999, P =0.048]., Conclusions: Patients undergoing ERAS protocols experience improved cost-effectiveness and reduced total cost by 2Y post-operatively. Due to the potential economic benefit of ERAS for patients incorporation of ERAS into practice for eligible patients should be considered., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background and Objectives: Achieving spinopelvic realignment during adult spinal deformity (ASD) surgery does not always produce ideal outcomes. Little is known whether compensation in lower extremities (LEs) plays a role in this disassociation. The objective is to analyze lower extremity compensation after complex ASD surgery, its effect on outcomes, and whether correction can alleviate these mechanisms., Methods: We included patients with complex ASD with 6-week data. LE parameters were as follows: sacrofemoral angle, knee flexion angle, and ankle flexion angle. Each parameter was ranked, and upper tertile was deemed compensation. Patients compensating and not compensating postoperatively were propensity score matched for body mass index, frailty, and T1 pelvic angle. Linear regression assessed correlation between LE parameters and baseline deformity, demographics, and surgical details. Multivariate analysis controlling for baseline deformity and history of total knee/hip arthroplasty evaluated outcomes., Results: Two hundred and ten patients (age: 61.3 ± 14.1 years, body mass index: 27.4 ± 5.8 kg/m2, Charlson Comorbidity Index: 1.1 ± 1.6, 72% female, 22% previous total joint arthroplasty, 24% osteoporosis, levels fused: 13.1 ± 3.8) were included. At baseline, 59% were compensating in LE: 32% at hips, 39% knees, and 36% ankles. After correction, 61% were compensating at least one joint. Patients undercorrected postoperatively were less likely to relieve LE compensation (odds ratio: 0.2, P = .037). Patients compensating in LE were more often undercorrected in age-adjusted pelvic tilt, pelvic incidence, lumbar lordosis, and T1 pelvic angle and disproportioned in Global Alignment and Proportion (P < .05). Patients matched in sagittal age-adjusted score at 6 weeks but compensating in LE were more likely to develop proximal junctional kyphosis (odds ratio: 4.1, P = .009) and proximal junctional failure (8% vs 0%, P = .035) than those sagittal age-adjusted score-matched and not compensating in LE., Conclusion: Perioperative lower extremity compensation was a product of undercorrecting complex ASD. Even in age-adjusted realignment, compensation was associated with global undercorrection and junctional failure. Consideration of lower extremities during planning is vital to avoid adverse outcomes in perioperative course after complex ASD surgery., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Study Design/setting: This was a retrospective cohort study., Background: Little is known of the intersection between surgical invasiveness, cervical deformity (CD) severity, and frailty., Objective: The aim of this study was to investigate the outcomes of CD surgery by invasiveness, frailty status, and baseline magnitude of deformity., Methods: This study included CD patients with 1-year follow-up. Patients stratified in high deformity if severe in the following criteria: T1 slope minus cervical lordosis, McGregor's slope, C2-C7, C2-T3, and C2 slope. Frailty scores categorized patients into not frail and frail. Patients are categorized by frailty and deformity (not frail/low deformity; not frail/high deformity; frail/low deformity; frail/high deformity). Logistic regression assessed increasing invasiveness and outcomes [distal junctional failure (DJF), reoperation]. Within frailty/deformity groups, decision tree analysis assessed thresholds for an invasiveness cutoff above which experiencing a reoperation, DJF or not achieving Good Clinical Outcome was more likely., Results: A total of 115 patients were included. Frailty/deformity groups: 27% not frail/low deformity, 27% not frail/high deformity, 23.5% frail/low deformity, and 22.5% frail/high deformity. Logistic regression analysis found increasing invasiveness and occurrence of DJF [odds ratio (OR): 1.03, 95% CI: 1.01-1.05, P =0.002], and invasiveness increased with deformity severity ( P <0.05). Not frail/low deformity patients more often met Optimal Outcome with an invasiveness index <63 (OR: 27.2, 95% CI: 2.7-272.8, P =0.005). An invasiveness index <54 for the frail/low deformity group led to a higher likelihood of meeting the Optimal Outcome (OR: 9.6, 95% CI: 1.5-62.2, P =0.018). For the frail/high deformity group, patients with a score <63 had a higher likelihood of achieving Optimal Outcome (OR: 4.8, 95% CI: 1.1-25.8, P =0.033). There was no significant cutoff of invasiveness for the not frail/high deformity group., Conclusions: Our study correlated increased invasiveness in CD surgery to the risk of DJF, reoperation, and poor clinical success. The thresholds derived for deformity severity and frailty may enable surgeons to individualize the invasiveness of their procedures during surgical planning to account for the heightened risk of adverse events and minimize unfavorable outcomes., Competing Interests: P.G.P.: Allosource: Other financial or material support; Cervical Scoliosis Research Society: Research support; Globus Medical: Paid presenter or speaker; Medtronic: Paid consultant; Royal Biologics: Paid consultant; Spine: Editorial or governing board; SpineWave: Paid consultant; Terumo: Paid consultant; Zimmer: Paid presenter or speaker. V.L.: DePuy, A Johnson & Johnson Company: Paid presenter or speaker; European Spine Journal : Editorial or governing board; Globus Medical: Paid consultant; International Spine Study Group: Board or committee member; Nuvasive: IP royalties; Scoliosis Research Society: Board or committee member; The Permanente Medical Group: Paid presenter or speaker. R.F.: Nemaris: Stock or stock options. H.J.K.: AAOS: Board or committee member; Alphatec Spine: Paid consultant; AO SPINE: Board or committee member; Cervical Spine Research Society: Board or committee member; HSS Journal , Asian Spine Journal : Editorial or governing board; ISSGF: Research support; K2M: IP royalties; Scoliosis Research Society: Board or committee member; Zimmer: IP royalties. A.H.D.: EOS: Paid consultant; Medicrea: Paid consultant; Medtronic Sofamor Danek: Paid consultant; Novabone: Paid consultant; Orthofix Inc.: Paid consultant; Research support; Southern Spine: IP royalties; Spineart: IP royalties; Paid consultant; Springer: Publishing royalties, financial or material support; Stryker: Paid consultant. J.L.G.: Acuity: IP royalties; Paid consultant; Alan L. & Jacqueline B. Stuart Spine Research: Research support; Cerapedics: Research support; Cingulate Therapeutics: Stock or stock Options; DePuy, A Johnson & Johnson Company: Paid presenter or speaker; Global Spine Journal —Reviewer: Editorial or governing board; Intellirod Spine Inc.: Research support; K2M /Stryker: Board or committee member; MAZOR Surgical Technologies: Paid consultant; Medtronic: Board or committee member; Paid consultant; Research support; Norton Healthcare: Research support; Nuvasive: IP royalties; Paid consultant; Pfizer: Research support; Scoliosis Research Society: Research support; Spine Deformity —Reviewer: Editorial or governing board; Stryker: Paid consultant; Paid presenter or speaker; Texas Scottish Rite Hospital: Research support; The Spine Journal —Reviewer: Editorial or governing board. T.S.P.: Altus: IP royalties; Globus Medical: Paid consultant; Medicrea: Paid consultant; Medtronic: Paid consultant; Nuvasive: Paid consultant; Spine Align: Stock or stock Options; Stryker: Paid consultant; Torus Medical: Stock or stock Options. G.M.M.: Carlsmed: Paid consultant; ISSGF: Research support; K2M: IP royalties; Nuvasive: IP royalties; Paid consultant; Research support; Scoliosis Research Society: Board or committee member; SeaSpine: Paid consultant; Stryker: Paid consultant; Viseon: Paid consultant. R.K.E.: Aesculap/B.Braun: Paid consultant; Alphatec Spine: Stock or stock Options; Baxter: Paid consultant; Biedermann-Motech: Paid consultant; Carevature: Paid consultant; Stock or stock Options; Globus Medical: IP royalties; Invuity: Stock or stock Options; Medtronic: Paid consultant; Nocimed: Stock or stock Options; Nuvasive: IP royalties; Paid consultant; Research support; Stock or stock Options; Radius: Paid presenter or speaker; San Diego Spine Foundation: Board or committee member; Scoliosis Research Society: Board or committee member; Seaspine: IP royalties; Paid consultant; Stock or stock Options; SI Bone: IP royalties; Paid consultant; Society of Lateral Access Surgery: Board or committee member; Spine Innovations: Stock or stock Options; Stryker: Paid consultant. K.H.: European Spine Journal : Editorial or governing board; Nuvasive: Research support. E.O.K.: AO Spine: Paid presenter or speaker; Research support; DePuy, A Johnson & Johnson Company: Paid consultant; Medicrea: Paid consultant; Medtronic: Paid consultant; Stryker: Paid consultant. B.G.L.: ISSGF: Paid consultant. R.A.H.: American Orthopaedic Association: Board or committee member; Cervical Spine Research Society: Board or committee member; DePuy, A Johnson & Johnson Company: IP royalties; Paid consultant; Paid presenter or speaker; Globus Medical: IP royalties; Paid consultant; Paid presenter or speaker; International Spine Study Group: Board or committee member; ISSLS Textbook of the Lumbar Spine: Editorial or governing board; Medtronic: Paid consultant; Paid presenter or speaker; North American Spine Society: Board or committee member; Orthofix Inc.: Paid consultant; Paid presenter or speaker; Scoliosis Research Society: Board or committee member; SeaSpine: IP royalties; Spine Connect: Stock or stock Options; Western Ortho Assn: Board or committee member. D.C.B.: Bioventus: Research support; DePuy, A Johnson & Johnson Company: IP royalties; Paid consultant; Research support; Pfizer: Research support; Progenerative Medical: Stock or stock Options; Scoliosis Research Society: Board or committee member; Spine Deformity : Editorial or governing board. P.V.M.: AANS/CNS Spine Section and Scoliosis Research Society: Board or committee member; American Association of Neurological Surgeons: Board or committee member; Cervical Spine Research Society: Board or committee member; Congress of Neurological Surgeons: Board or committee member; DePuy, A Johnson & Johnson Company: IP royalties; Paid consultant; Global Spine Journal : Editorial or governing board; Globus Medical: Paid consultant; International Spine Study Group: Research support; Neurosurgery: Editorial or governing board; NREF: Research support; Spinal Deformity: Editorial or governing board; Spinicity/ISD: Stock or stock Options; Springer: Publishing royalties, financial or material support; Stryker: Paid consultant; Taylor and Francis: Publishing royalties, financial or material support; Thieme: Publishing royalties, financial or material support; World Neurosurgery: Editorial or governing board. P.P.: AANS Spine Section: Board or committee member; Cerapedics: Research support; DePuy, A Johnson & Johnson Company: Research support; Globus Medical: IP royalties; Paid consultant; ISSG: Research support; Journal of Neurosurgery Spine : Editorial or governing board; Neurosurgery: Editorial or governing board; North American Spine Society: Board or committee member; Nuvasive: Paid consultant; Operative Neurosurgery: Editorial or governing board; Scoliosis Research Society: Board or committee member; SI-Bone: Research support. F.J.S.: DePuy, A Johnson & Johnson Company: Research support; Globus Medical: Paid consultant; Paid presenter or speaker; K2M: IP royalties; Paid consultant; Paid presenter or speaker; Medicrea: Paid consultant; Medtronic: Paid consultant; Medtronic Sofamor Danek: IP royalties; Paid presenter or speaker; Nuvasive: Research support; Scoliosis Research Society: Board or committee member; Spine Deformity : Editorial or governing board; Stryker: Research support; VP of International Spine Society Group (ISSG): Board or committee member; Zimmer: IP royalties; Paid consultant; Paid presenter or speaker. D.C.: Globus Medical: IP royalties; Paid consultant. C.I.S.: AANS: Board or committee member; Cervical Spine Research Society: Board or committee member; DePuy, A Johnson & Johnson Company: Paid presenter or speaker; Research support; Globus Medical: Research support; Medtronic: Other financial or material support; Paid consultant; Medtronic Sofamor Danek: IP royalties; Paid presenter or speaker; Research support; Neurosurgery RRC: Board or committee member; Nuvasive: IP royalties; Paid consultant; Paid presenter or speaker; Research support; Stock or stock Options; Proprio: Paid consultant; Scoliosis Research Society: Board or committee member; SI Bone: IP royalties; Spinal Deformity: Editorial or governing board; Spine: Editorial or governing board. R.S.B.: allosource: Paid consultant; Research support; Biomet: Research support; DePuy, A Johnson & Johnson Company: Paid consultant; Research support; EOS: Research support; Globus Medical: Research support; k2 medical: IP royalties; Paid consultant; Paid presenter or speaker; Research support; Medtronic Sofamor Danek: Research support; North American Spine Society: Board or committee member; Nuvasive: IP royalties; Research support; Orthofix Inc.: Research support; Scoliosis Research Society: Board or committee member; Stryker: IP royalties; Paid presenter or speaker. C.P.A.: Biomet Spine: IP royalties; DePuy, A Johnson & Johnson Company: IP royalties; Paid consultant; Research support; Global Spine Analytics—Director: Other financial or material support; International Spine Study Group (ISSG): Research support; International Spine Study Group (ISSG)—Executive Committee: Other financial or material support; K2M: IP royalties; Paid consultant; Medicrea: IP royalties; Paid consultant; Medtronic: Paid consultant; Next Orthosurgical: IP royalties; Nuvasive: IP royalties; Operative Neurosurgery—Editorial Board: Other financial or material support; Scoliosis Research Society (SRS)—Grant Funding: Other financial or material support; Stryker: IP royalties; Titan Spine: Research support. J.S.S.: Alphatec Spine: Stock or stock Options; Carlsmed: Paid consultant; Cerapedics: Paid consultant; DePuy: Research support; DePuy, A Johnson & Johnson Company: Paid consultant; Journal of Neurosurgery Spine : Editorial or governing board; Neurosurgery: Editorial or governing board; Nuvasive: IP royalties; Paid consultant; Research support; Operative Neurosurgery: Editorial or governing board; Scoliosis Research Society: Board or committee member; Spine Deformity : Editorial or governing board; Stryker: Paid consultant; Thieme: Publishing royalties, financial or material support; Zimmer: IP royalties; paid consultant. The remaining authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The objective was to determine the degree of regional decompensation to pelvic tilt (PT) normalization after complex adult spinal deformity (ASD) surgery., Methods: Operative ASD patients with 1 year of PT measurements were included. Patients with normalized PT at baseline were excluded. Predicted PT was compared to actual PT, tested for change from baseline, and then compared against age-adjusted, Scoliosis Research Society-Schwab, and global alignment and proportion (GAP) scores. Lower-extremity (LE) parameters included the cranial-hip-sacrum angle, cranial-knee-sacrum angle, and cranial-ankle-sacrum angle. LE compensation was set as the 1-year upper tertile compared with intraoperative baseline. Univariate analyses were used to compare normalized and nonnormalized data against alignment outcomes. Multivariable logistic regression analyses were used to develop a model consisting of significant predictors for normalization related to regional compensation., Results: In total, 156 patients met the inclusion criteria (mean ± SD age 64.6 ± 9.1 years, BMI 27.9 ± 5.6 kg/m2, Charlson Comorbidity Index 1.9 ± 1.6). Patients with normalized PT were more likely to have overcorrected pelvic incidence minus lumbar lordosis and sagittal vertical axis at 6 weeks (p < 0.05). GAP score at 6 weeks was greater for patients with nonnormalized PT (0.6 vs 1.3, p = 0.08). At baseline, 58.5% of patients had compensation in the thoracic and cervical regions. Postoperatively, compensation was maintained by 42% with no change after matching in age-adjusted or GAP score. The patients with nonnormalized PT had increased rates of thoracic and cervical compensation (p < 0.05). Compensation in thoracic kyphosis differed between patients with normalized PT at 6 weeks and those with normalized PT at 1 year (69% vs 35%, p < 0.05). Those who compensated had increased rates of implant complications by 1 year (OR [95% CI] 2.08 [1.32-6.56], p < 0.05). Cervical compensation was maintained at 6 weeks and 1 year (56% vs 43%, p = 0.12), with no difference in implant complications (OR 1.31 [95% CI -2.34 to 1.03], p = 0.09). For the lower extremities at baseline, 61% were compensating. Matching age-adjusted alignment did not eliminate compensation at any joint (all p > 0.05). Patients with nonnormalized PT had higher rates of LE compensation across joints (all p < 0.01). Overall, patients with normalized PT at 1 year had the greatest odds of resolving LE compensation (OR 9.6, p < 0.001). Patients with normalized PT at 1 year had lower rates of implant failure (8.9% vs 19.5%, p < 0.05), rod breakage (1.3% vs 13.8%, p < 0.05), and pseudarthrosis (0% vs 4.6%, p < 0.05) compared with patients with nonnormalized PT. The complication rate was significantly lower for patients with normalized PT at 1 year (56.7% vs 66.1%, p = 0.02), despite comparable health-related quality of life scores., Conclusions: Patients with PT normalization had greater rates of resolution in thoracic and LE compensation, leading to lower rates of complications by 1 year. Thus, consideration of both the lower extremities and thoracic regions in surgical planning is vital to preventing adverse outcomes and maintaining pelvic alignment.

Study Design: Retrospective review of prospective multicenter data., Objectives: This study aimed to investigate the shape of TK before and after fusion in ASD patients treated with long fusion., Methods: ASD patients undergoing posterior spinal fusions including at least T5 to L1 without prior fusion extending to the thoracic spine were included. Patients were categorized based on the preoperative T1-T12 kyphosis into: Hypo-TK (if < 30°), Normal-TK, and Hyper-TK (if > 70°). Regional kyphosis at T10-L1 (Distal), T5-T10 (Middle), and T1-T5 (Proximal) and their relative contributions to total kyphosis were compared between groups, and the pre-to postoperative changes were investigated using paired t test., Results: In total, 329 patients were included in this analysis (mean age: 57 ± 16 years, 79.6% female). Preoperative T1-T12 TK for the entire cohort was 40.9 ± 2° (32% Hypo-TK, 11% Hyper-TK, 57% Normal-TK). The Hypo-TK group had the smallest distal TK (5.9 vs 17.1 & 26.0), and middle TK (8.0 vs 25.3 & 45.4), but the percentage of contribution to total kyphosis was not significantly different (Distal: 24.1% vs 34.1% vs 32.8%; Middle: 46.6% vs 53.9% vs 56.8%, all P > .1). Postoperatively, T1-12 TK increased significantly (40.9 ± 2.0° vs 57.8 ± 17.6°). Each group had a decrease in distal kyphosis (Hypo-TK 2.6 ± 10.4°; Normal-TK 8.9 ± 11.5°; Hyper-TK 14.9 ± 12°, all P < .05). The middle kyphosis significantly decreased for Hyper-TK (11.8 ± 12.4) and increased for both Normal-TK and Hypo-TK (3.8 ± 11° and 14.2 ± 11°). Proximal TK increased significantly for all groups by 14-18°. Deterioration from Normal-TK to Hyper-TK postoperatively was associated with lower rate of patient satisfaction (59.6% vs 77.3%, P = .032)., Conclusions: Posterior spinal fusion for ASD alters the magnitude and shape of thoracic kyphosis. While 60% of patients had a normal TK at baseline, 30% of those patients developed iatrogenic hyperkyphosis postoperatively. Patients with baseline hypokyphosis were more likely to be corrected to normal TK than hyperkyphotic patients. Future research should investigate TK restoration in ASD and its impact on clinical outcomes and complications., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study Design: Retrospective cohort study., Objective: Understand the benefit of addressing malalignment in revision surgery for proximal junctional kyphosis (PJK)., Summary of Background Data: PJK is a common cause of revision surgery for adult spinal deformity patients. During a revision, surgeons may elect to perform a proximal extension of the fusion, or also correct the source of the lumbopelvic mismatch., Materials and Methods: Recurrent PJK following revision surgery was the primary outcome. Revision surgical strategy was the primary predictor (proximal extension of fusion alone compared with combined sagittal correction and proximal extension). Multivariable logistic regression determined rates of recurrent PJK between the two surgical groups with lumbopelvic surgical correction assessed through improving ideal alignment in one or more alignment criteria [Global Alignment and Proportionality (GAP), Roussouly-type, and Sagittal Age-Adjusted Score (SAAS)]., Results: A total of 151 patients underwent revision surgery for PJK. PJK occurred at a rate of 43.0%, and PJF at 12.6%. Patients proportioned in GAP postrevision had lower rates of recurrent PJK [23% vs. 42%; odds ratio (OR): 0.3, 95% confidence interval (CI): 0.1-0.8, P =0.024]. Following adjusted analysis, patients who were ideally aligned in one of three criteria (Matching in SAAS and/or Roussouly matched and/or achieved GAP proportionality) had lower rates of recurrent PJK (36% vs. 53%; OR: 0.4, 95% CI: 0.1-0.9, P =0.035) and recurrent PJF (OR: 0.1, 95% CI: 0.02-0.7, P =0.015). Patients ideally aligned in two of three criteria avoid any development of PJF (0% vs. 16%, P <0.001)., Conclusions: Following revision surgery for PJK, patients with persistent poor sagittal alignment showed increased rates of recurrent PJK compared with patients who had abnormal lumbopelvic alignment corrected during the revision. These findings suggest addressing the root cause of surgical failure in addition to proximal extension of the fusion may be beneficial., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Multicenter comparative cohort., Objective: Studies have shown markedly higher rates of complications and all-cause mortality following surgery for adult cervical deformity (ACD) compared with adult thoracolumbar deformity (ATLD), though the reasons for these differences remain unclear. Our objectives were to compare baseline frailty, disability, and comorbidities between ACD and complex ATLD patients undergoing surgery., Methods: Two multicenter prospective adult spinal deformity registries were queried, one ATLD and one ACD. Baseline clinical and frailty measures were compared between the cohorts., Results: 616 patients were identified (107 ACD and 509 ATLD). These groups had similar mean age (64.6 vs 60.8 years, respectively, P = .07). ACD patients were less likely to be women (51.9% vs 69.5%, P < .001) and had greater Charlson Comorbidity Index (1.5 vs .9, P < .001) and ASA grade (2.7 vs 2.4, P < .001). ACD patients had worse VR-12 Physical Component Score (PCS, 25.7 vs 29.9, P < .001) and PROMIS Physical Function Score (33.3 vs 35.3, P = .031). All frailty measures were significantly worse for ACD patients, including hand dynamometer (44.6 vs 55.6 lbs, P < .001), CSHA Clinical Frailty Score (CFS, 4.0 vs 3.2, P < .001), and Edmonton Frailty Scale (EFS, 5.15 vs 3.21, P < .001). Greater proportions of ACD patients were frail (22.9% vs 5.7%) or vulnerable (15.6% vs 10.9%) based on EFS ( P < .001)., Conclusions: Compared with ATLD patients, ACD patients had worse baseline characteristics on all measures assessed (comorbidities/disability/frailty). These differences may help account for greater risk of complications and all-cause mortality previously observed in ACD patients and facilitate strategies for better preoperative optimization., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study Design: Retrospective review of a prospectively enrolled adult spinal deformity (ASD) database., Objective: To investigate what patient factors elevate the risk of sub-optimal outcomes after deformity correction., Background: Currently, it is unknown what factors predict a poor outcome after adult spinal deformity surgery, which may require increased preoperative consideration and counseling., Materials and Methods: Patients >18 yrs undergoing surgery for ASD(scoliosis≥20°, SVA≥5 cm, PT≥25°, or TK≥60°). An unsatisfactory outcome was defined by the following categories met at two years: (1) clinical: deteriorating in ODI at two years follow-up (2) complications/reoperation: having a reoperation and major complication were deemed high risk for poor outcomes postoperatively (HR). Multivariate analyses assessed predictive factors of HR patients in adult spinal deformity patients., Results: In all, 633 adult spinal deformity (59.9 yrs, 79% F, 27.7 kg/m 2, CCI: 1.74) were included. Baseline severe Schwab modifier incidence (++): 39.2% pelvic incidence and lumbar lordosis, 28.8% sagittal vertical axis, 28.9% PT. Overall, 15.5% of patients deteriorated in ODI by two years, while 7.6% underwent reoperation and had a major complication. This categorized 11 (1.7%) as HR. HR were more comorbid in terms of arthritis (73%), heart disease (36%), and kidney disease (18%), P <0.001. Surgically, HR had greater EBL (4431ccs) and underwent more osteotomies (91%), specifically Ponte(36%) and Three Column Osteotomies(55%), which occurred more at L2(91%). HR underwent more PLIFs (45%) and had more blood transfusion units (2641ccs), all P <0.050. The multivariate regression determined a combination of a baseline Distress and Risk Assessment Method score in the 75th percentile, having arthritis and kidney disease, a baseline right lower extremity motor score ≤3, cSVA >65 mm, C2 slope >30.2°, CTPA >5.5° for an R2 value of 0.535 ( P <0.001)., Conclusions: When addressing adult spine deformities, poor outcomes tend to occur in severely comorbid patients with major baseline psychological distress scores, poor neurologic function, and concomitant cervical malalignment., Competing Interests: P.G.P.: Cerapedics: Other financial or material support; Cervical Scoliosis Research Society: Research support; Globus Medical: Paid presenter or speaker; Medtronic: Paid consultant; Royal Biologics: Paid consultant; Spine: Editorial or governing board; Spinevision: Other financial or material support; SpineWave: Paid consultant; Terumo: Paid consultant; The remaining authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: While reimbursement is centered on 90-day outcomes, many patients may still achieve optimal, long-term outcomes following adult spinal deformity (ASD) surgery despite transient short-term complications., Objective: Compare long-term clinical success and cost-utility between patients achieving optimal realignment and suboptimally aligned peers., Study Design/setting: Retrospective cohort study of a prospectively collected multicenter database., Methods: ASD patients with two-year (2Y) data included. Groups were propensity score matched (PSM) for age, frailty, body mass index (BMI), Charlson Comorbidity Index (CCI), and baseline deformity. Optimal radiographic criteria are defined as meeting low deformity in all three (Scoliosis Research Society) SRS-Schwab parameters or being proportioned in Global Alignment and Proportionality (GAP). Cost-per-QALY was calculated for each time point. Multivariable logistic regression analysis and ANCOVA (analysis of covariance) adjusting for baseline disability and deformity (pelvic incidence (PI), pelvic incidence minus lumbar lordosis (PI-LL)) were used to determine the significance of surgical details, complications, clinical outcomes, and cost-utility., Results: A total of 930 patients were considered. Following PSM, 253 "optimal" (O) and 253 "not optimal" (NO) patients were assessed. The O group underwent more invasive procedures and had more levels fused. Analysis of complications by two years showed that the O group suffered less overall major (38% vs. 52%, p = 0.021) and major mechanical complications (12% vs. 22%, p = 0.002), and less reoperations (23% vs. 33%, p = 0.008). Adjusted analysis revealed O patients more often met MCID (minimal clinically important difference) in SF-36 PCS, SRS-22 Pain, and Appearance. Cost-utility-adjusted analysis determined that the O group generated better cost-utility by one year and maintained lower overall cost and costs per QALY (both p < 0.001) at two years., Conclusions: Fewer late complications (mechanical and reoperations) are seen in optimally aligned patients, leading to better long-term cost-utility overall. Therefore, the current focus on avoiding short-term complications may be counterproductive, as achieving optimal surgical correction is critical for long-term success.

Background: Adult spinal deformity (ASD) surgery can improve patient pain and physical function but is associated with high complication rates and long postoperative recovery. Accordingly, if given a choice, patients may indicate they would not undergo ASD surgery again., Purpose: Evaluate surgically treated ASD patients to assess if given the option (1) would surgically treated ASD patients choose to undergo the same ASD surgery again, (2) would the treating surgeon perform the same ASD surgery again and if not why, (3) evaluate for consensus and/or discrepancies between patient and surgeon opinions for willingness to perform/receive the same surgery, and (4) evaluate for associations with willingness to undergo or not undergo the same surgery again and patient demographics, patient reported outcomes, and postoperative complications., Study Design: Retrospective review of a prospective ASD study., Patient Sample: Surgically treated ASD patients enrolled into a multicenter prospective study., Outcome Measures: Scoliosis Research Society-22r questionnaire (SRS-22r), Short Form-36v2 questionnaire (SF-36) physical component summary (PCS) and mental component summary (MCS), Oswestry Disability Index (ODI), numeric pain rating for back pain (NRS back) and leg pain (NRS leg), minimal clinically important difference (MCID) for SRS-22r domains and ODI, intraoperative and postoperative complications, surgeon and patient satisfaction with surgery., Methods: Surgically treated ASD patients prospectively enrolled into a multicenter study were asked at minimum 2-year postoperative, if, based upon their hospital and surgical experiences and surgical recovery experiences, would the patient undergo the same surgery again. Treating surgeons were then matched to their corresponding patients, blinded to the patients' preoperative and postoperative patient reported outcome measures, and interviewed and asked if (1) the surgeon believed that the corresponding patient would undergo the surgery again, (2) if the surgeon believed the corresponding patient was improved by the surgery and (3) if the surgeon would perform the same surgery on the corresponding patient again, and if not why. ASD patients were divided into those indicating they would (YES), would not (NO) or were unsure (UNSURE) if they would have same surgery again. Agreement between patient and surgeon willingness to receive/perform the same surgery was assessed and correlations between patient willingness for same surgery, postoperative complications, spine deformity correction, patient reported outcomes (PROs)., Results: A total of 580 of 961 ASD patients eligible for study were evaluated. YES (n=472) had similar surgical procedures performed, similar duration of hospital and ICU stay, similar spine deformity correction and similar postoperative spinal alignment as NO (n=29; p>.05). UNSURE (n=79) had greater preoperative depression and opioid use rates, UNSURE and NO had more postoperative complications requiring surgery, and UNSURE and NO had fewer percentages of patients reaching postoperative MCID for SRS-22r domains and MCID for ODI than YES (p<.05). Comparison of patient willingness to receive the same surgery versus surgeon perceptions on patient's willingness to receive the same surgery demonstrated surgeons accurately identified YES (91.1%) but poorly identified NO (13.8%; p<.05)., Conclusions: If given a choice, 18.6% of surgically treated ASD patients indicated they were unsure or would not undergo the surgery again. ASD patients indicating they were unsure or would not undergo ASD surgery again had greater preoperative depression, greater preoperative opioid use, worse postoperative PROs, fewer patients reaching MCID, more complications requiring surgery, and greater postoperative opioid use. Additionally, patients that indicated they would not have the same surgery again were poorly identified by their treating surgeons compared to patients indicating they would be willing to receive the same surgery again. More research is needed to understand patient expectations and improve patient experiences following ASD surgery., Competing Interests: Declaration of competing interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background and Objectives: Mitigating post-operative complications is a key metric of success following interbody fusion. LLIF is associated with a unique complication profile when compared to other approaches, and while numerous studies have attempted to report the incidence of post-operative complications, there is currently no consensus regarding their definitions or reporting structure. The aim of this study was to standardize the classification of complications specific to lateral lumbar interbody fusion (LLIF). Materials and Methods : A search algorithm was employed to identify all the articles that described complications following LLIF. A modified Delphi technique was then used to perform three rounds of consensus among twenty-six anonymized experts across seven countries. Published complications were classified as major, minor, or non-complications using a 60% agreement threshold for consensus. Results: A total of 23 articles were extracted, describing 52 individual complications associated with LLIF. In Round 1, forty-one of the fifty-two events were identified as a complication, while seven were considered to be approach-related occurrences. In Round 2, 36 of the 41 events with complication consensus were classified as major or minor. In Round 3, forty-nine of the fifty-two events were ultimately classified into major or minor complications with consensus, while three events remained without agreement. Vascular injuries, long-term neurologic deficits, and return to the operating room for various etiologies were identified as important consensus complications following LLIF. Non-union did not reach significance and was not classified as a complication. Conclusions: These data provide the first, systematic classification scheme of complications following LLIF. These findings may improve the consistency in the future reporting and analysis of surgical outcomes following LLIF.

Study Design: Diagnostic binary threshold analysis., Objective: (1) Perform a sensitivity analysis demonstrating the test performance metrics for any combination of proximal junctional angle (PJA) magnitude and change; (2) Propose a new proximal junctional kyphosis (PJK) criteria., Summary of Background Data: Previous definitions of PJK have been arbitrarily selected and then tested through retrospective case series, often showing little correlation with clinical outcomes., Materials and Methods: Surgically treated adult spinal deformity patients (≥4 levels fused) enrolled into a prospective, multicenter database were evaluated at a minimum 2-year follow-up for proximal junctional failure (PJF). Using PJF as the outcome of interest, test performance metrics including sensitivity, positive predictive value, and F1 metrics (harmonic mean of precision and recall) were calculated for all combinations of PJA magnitude and change using different combinations of perijunctional vertebrae. The combination with the highest F1 score was selected as the new PJK criteria. Performance metrics of previous PJK definitions and the new PJK definition were compared., Results: Of the total, 669 patients were reviewed. PJF rate was 10%. Overall, the highest F1 scores were achieved when the upper instrumented vertebrae -1 (UIV-1)/UIV+2 angle was measured. For lower thoracic cases, out of all the PJA and magnitude/change combinations tested, a UIV-1/UIV+2 magnitude of -28° and a change of -20° was associated with the highest F1 score. For upper thoracic cases, a UIV-1/UIV+2 magnitude of -30° and a change of -24° were associated with the highest F1 score. Using PJF as the outcome, patients meeting this new criterion (11.5%) at 6 weeks had the lowest survival rate (74.7%) at 2 years postoperative, compared with Glattes (84.4%) and Bridwell (77.4%)., Conclusions: Out of all possible PJA magnitude and change combinations, without stratifying by upper thoracic versus lower thoracic fusions, a magnitude of ≤-28° and a change of ≤-22° provide the best test performance metrics for predicting PJF., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Three-column osteotomies (3COs), usually in the form of pedicle subtraction or vertebral column resection, have become common in adult spinal deformity surgery. Although a powerful tool for deformity correction, 3COs can increase the risks of perioperative morbidity., Methods: Operative patients with adult spinal deformity (Cobb angle of >20°, sagittal vertical axis [SVA] of >5 cm, pelvic tilt of >25°, and/or thoracic kyphosis of >60°) with available baseline and 2-year radiographic and health-related quality-of-life (HRQoL) data were included. Patients were stratified into 2 groups by surgical year: Group I (2008 to 2013) and Group II (2014 to 2018). Patients with 3COs were then isolated for outcomes analysis. Severe sagittal deformity was defined by an SVA of >9.5 cm. Best clinical outcome (BCO) was defined as an Oswestry Disability Index (ODI) of <15 and Scoliosis Research Society (SRS)-22 of >4.5. Multivariable regression analyses were used to assess differences in surgical, radiographic, and clinical parameters., Results: Seven hundred and fifty-two patients with adult spinal deformity met the inclusion criteria, and 138 patients underwent a 3CO. Controlling for baseline SVA, PI-LL (pelvic incidence minus lumbar lordosis), revision status, age, and Charlson Comorbidity Index (CCI), Group II was less likely than Group I to have a 3CO (21% versus 31%; odds ratio [OR] = 0.6; 95% confidence interval [CI] = 0.4 to 0.97) and more likely to have an anterior lumbar interbody fusion (ALIF; OR = 1.6; 95% CI = 1.3 to 2.3) and a lateral lumbar interbody fusion (LLIF; OR = 3.8; 95% CI = 2.3 to 6.2). Adjusted analyses showed that Group II had a higher likelihood of supplemental rod usage (OR = 21.8; 95% CI = 7.8 to 61) and a lower likelihood of proximal junctional failure (PJF; OR = 0.23; 95% CI = 0.07 to 0.76) and overall hardware complications by 2 years (OR = 0.28; 95% CI = 0.1 to 0.8). In an adjusted analysis, Group II had a higher likelihood of titanium rod usage (OR = 2.7; 95% CI = 1.03 to 7.2). Group II had a lower 2-year ODI and higher scores on Short Form (SF)-36 components and SRS-22 total (p < 0.05 for all). Controlling for baseline ODI, Group II was more likely to reach the BCO for the ODI (OR = 2.8; 95% CI = 1.2 to 6.4) and the SRS-22 total score (OR = 4.6; 95% CI = 1.3 to 16)., Conclusions: Over a 10-year period, the rates of 3CO usage declined, including in cases of severe deformity, with an increase in the usage of PJF prophylaxis. A better understanding of the utility of 3CO, along with a greater implementation of preventive measures, has led to a decrease in complications and PJF and a significant improvement in patient-reported outcome measures., Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H179 )., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

Objective: Adult cervical deformity (ACD) has high complication rates due to surgical complexity and patient frailty. Very few studies have focused on longer-term outcomes of operative ACD treatment. The objective of this study was to assess minimum 2-year outcomes and complications of ACD surgery., Methods: A multicenter, prospective observational study was performed at 13 centers across the United States to evaluate surgical outcomes for ACD. Demographics, complications, radiographic parameters, and patient-reported outcome measures (PROMs; Neck Disability Index, modified Japanese Orthopaedic Association, EuroQol-5D [EQ-5D], and numeric rating scale [NRS] for neck and back pain) were evaluated, and analyses focused on patients with ≥ 2-year follow-up., Results: Of 169 patients with ACD who were eligible for the study, 102 (60.4%) had a minimum 2-year follow-up (mean 3.4 years, range 2-8.1 years). The mean age at surgery was 62 years (SD 11 years). Surgical approaches included anterior-only (22.8%), posterior-only (39.6%), and combined (37.6%). PROMs significantly improved from baseline to last follow-up, including Neck Disability Index (from 47.3 to 33.0) and modified Japanese Orthopaedic Association score (from 12.0 to 12.8; for patients with baseline score ≤ 14), neck pain NRS (from 6.8 to 3.8), back pain NRS (from 5.5 to 4.8), EQ-5D score (from 0.74 to 0.78), and EQ-5D visual analog scale score (from 59.5 to 66.6) (all p ≤ 0.04). More than half of the patients (n = 58, 56.9%) had at least one complication, with the most common complications including dysphagia, distal junctional kyphosis, instrumentation failure, and cardiopulmonary events. The patients who did not achieve 2-year follow-up (n = 67) were similar to study patients based on baseline demographics, comorbidities, and PROMs. Over the course of follow-up, 23 of the total 169 enrolled patients were reported to have died. Notably, these represent all-cause mortalities during the course of follow-up., Conclusions: This multicenter, prospective analysis demonstrates that operative treatment for ACD provides significant improvement of health-related quality of life at a mean 3.4-year follow-up, despite high complication rates and a high rate of all-cause mortality that is reflective of the overall frailty of this patient population. To the authors' knowledge, this study represents the largest and most comprehensive prospective effort to date designed to assess the intermediate-term outcomes and complications of operative treatment for ACD.

Objective: The aim was to determine whether applying Arbeitsgemeinschaft für Osteosynthesefragen (AO) principles for external fixation of long bone fracture to patients with a 3-column osteotomy (3CO) would be associated with reduced rod fracture (RF) rates., Summary of Background Data: AO dictate principles to follow when fixating long bone fractures: (1) decrease bone-rod distance; (2) increase the number of connecting rods; (3) increase the diameter of rods; (4) increase the working length of screws; (5) use multiaxial fixation. We hypothesized that applying these principles to patients undergoing a 3CO reduces the rate of RF., Methods: Patients were categorized as having RF versus no rod fracture (non-RF). Details on location and type of instrumentation were collected. Dedicated software was used to calculate the distance between osteotomy site and adjacent pedicle screws, angle between screws and the distance between the osteotomy site and rod. Classic sagittal spinopelvic parameters were evaluated., Results: The study included 170 patients (34=RF, 136=non-RF). There was no difference in age (P=0.224), sagittal vertical axis correction (P=0.287), or lumbar lordosis correction (P=0.36). There was no difference in number of screws cephalad (P=0.62) or caudal (P=0.31) to 3CO site. There was a lower rate of RF for patients with >2 rods versus 2 rods (P<0.001). Patients with multiplanar rod fixation had a lower rod fracture rate (P=0.01). For patients with only 2 rods (N=68), the non-RF cohort had adjacent screws that trended to have less angulation to each other (P=0.06) and adjacent screws that had a larger working length (P=0.03)., Conclusions: A portion of AO principles can be applied to 3CO to reduce RF rates. Placing more rods around a 3CO site, placing rods in multiple planes, and placing adjacent screws with a larger working length around the 3CO site is associated with lower RF rates., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The current literature has primarily focused on the 2-year outcomes of operative adult spinal deformity (ASD) treatment. Longer term durability is important given the invasiveness, complications, and costs of these procedures. The aim of this study was to assess minimum 3-year outcomes and complications of ASD surgery., Methods: Operatively treated ASD patients were assessed at baseline, follow-up, and through mailings. Patient-reported outcome measures (PROMs) included scores on the Oswestry Disability Index (ODI), Scoliosis Research Society-22r (SRS-22r) questionnaire, mental component summary (MCS) and physical component summary (PCS) of the SF-36, and numeric rating scale (NRS) for back and leg pain. Complications were classified as perioperative (≤ 90 days), delayed (90 days to 2 years), and long term (≥ 2 years). Analyses focused on patients with minimum 3-year follow-up., Results: Of 569 patients, 427 (75%) with minimum 3-year follow-up (mean ± SD [range] 4.1 ± 1.1 [3.0-9.6] years) had a mean age of 60.8 years and 75% were women. Operative treatment included a posterior approach for 426 patients (99%), with a mean ± SD 12 ± 4 fusion levels. Anterior lumbar interbody fusion was performed in 35 (8%) patients, and 89 (21%) underwent 3-column osteotomy. All PROMs improved significantly from baseline to last follow-up, including scores on ODI (45.4 to 30.5), PCS (31.0 to 38.5), MCS (45.3 to 50.6), SRS-22r total (2.7 to 3.6), SRS-22r activity (2.8 to 3.5), SRS-22r pain (2.3 to 3.4), SRS-22r appearance (2.4 to 3.5), SRS-22r mental (3.4 to 3.7), SRS-22r satisfaction (2.7 to 4.1), NRS for back pain (7.1 to 3.8), and NRS for leg pain (4.8 to 3.0) (all p < 0.001). Degradations in some outcome measures were observed between the 2-year and last follow-up evaluations, but the magnitudes of these degradations were modest and arguably not clinically significant. Overall, 277 (65%) patients had at least 1 complication, including 185 (43%) perioperative, 118 (27%) delayed, and 56 (13%) long term. Notably, the 142 patients who did not achieve 3-year follow-up were similar to the study patients in terms of demographic characteristics, deformities, and baseline PROMs and had similar rates and types of complications., Conclusions: This prospective multicenter analysis demonstrated that operative ASD treatment provided significant improvement of health-related quality of life at minimum 3-year follow-up (mean 4.1 years), suggesting that the benefits of surgery for ASD remain durable at longer follow-up. These findings should prove useful for counseling, cost-effectiveness assessments, and efforts to improve the safety of care.

Background: More sophisticated surgical techniques for correcting adult spinal deformity (ASD) have increased operative times, adding to physiologic stress on patients and increased complication incidence. This study aims to determine factors associated with operative time using a statistical learning algorithm., Methods: Retrospective review of a prospective multicenter database containing 837 patients undergoing long spinal fusions for ASD. Conditional inference decision trees identified factors associated with skin-to-skin operative time and cutoff points at which factors have a global effect. A conditional variable-importance table was constructed based on a nonreplacement sampling set of 2000 conditional inference trees. Means comparison for the top 15 variables at their respective significant cutoffs indicated effect sizes., Results: Included: 544 surgical ASD patients (mean age: 58.0 years; fusion length 11.3 levels; operative time: 378 minutes). The strongest predictor for operative time was institution/surgeon. Center/surgeons, grouped by decision tree hierarchy, a and b were, on average, 2 hours faster than center/surgeons c-f, who were 43 minutes faster than centers g-j, all P < 0.001. The next most important predictors were, in order, approach (combined vs posterior increases time by 139 minutes, P < 0.001), levels fused (<4 vs 5-9 increased time by 68 minutes, P < 0.050; 5-9 vs < 10 increased time by 47 minutes, P < 0.001), age (age <50 years increases time by 57 minutes, P < 0.001), and patient frailty (score <1.54 increases time by 65 minutes, P < 0.001). Surgical techniques, such as three-column osteotomies (35 minutes), interbody device (45 minutes), and decompression (48 minutes), also increased operative time. Both minor and major complications correlated with < 66 minutes of increased operative time. Increased operative time also correlated with increased hospital length of stay (LOS), increased estimated intraoperative blood loss (EBL), and inferior 2-year Oswestry Disability Index (ODI) scores., Conclusions: Procedure location and specific surgeon are the most important factors determining operative time, accounting for operative time increases <2 hours. Surgical approach and number of levels fused were also associated with longer operative times, respectively. Extended operative time correlated with longer LOS, higher EBL, and inferior 2-y ODI outcomes., Clinical Relevance: We further identified the poor outcomes associated with extended operative time during surgical correction of ASD, and attributed the useful predictors of time spent in the operating room, including site, surgeon, surgical approach, and the number of levels fused., Competing Interests: Declaration of Conflicting Interests: The International Spine Study Group (ISSG) is funded through research grants from DePuy Synthes, and supported the current work. Portions of this work were accepted for podium presentation at the North American Spine Society Conference, Orlando, Florida, United States, October 27, 2017., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2022 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.)

Study Design: Retrospective cohort study., Objective: We hypothesized that adult spinal deformity (ASD) surgery would be associated with improved work- and school-related productivity, as well as decreased rates of absenteeism., Summary of Background Data: ASD patients experience markedly decreased health-related quality of life along many dimensions., Methods: Only patients eligible for 2-year follow-up were included, and those with a history of previous spinal fusion were excluded. The primary outcome measures in this study were Scoliosis Research Society-22r score (SRS-22r) questions 9 and 17. A repeated measures mixed linear regression was used to analyze responses over time among patients managed operatively (OP) versus nonoperatively (NON-OP)., Results: In total, 1188 patients were analyzed. 66.6% were managed operatively. At baseline, the mean percentage of activity at work/school was 56.4% (standard deviation [SD] 35.4%), and the mean days off from work/school over the past 90 days was 1.6 (SD 1.8). Patients undergoing ASD surgery exhibited an 18.1% absolute increase in work/school productivity at 2-year follow-up versus baseline (P < 0.0001), while no significant change was observed for the nonoperative cohort (P > 0.5). Similarly, the OP cohort experienced 1.1 fewer absent days over the past 90 days at 2 years versus baseline (P < 0.0001), while the NON-OP cohort showed no such difference (P > 0.3). These differences were largely preserved after stratifying by baseline employment status, age group, sagittal vertical axis (SVA), pelvic incidence minus lumbar lordosis (PI-LL), and deformity curve type., Conclusion: ASD patients managed operatively exhibited an average increase in work/school productivity of 18.1% and decreased absenteeism of 1.1 per 90 days at 2-year follow-up, while patients managed nonoperatively did not exhibit change from baseline. Given the age distribution of patients in this study, these findings should be interpreted as pertaining primarily to obligations at work or within the home. Further study of the direct and indirect economic benefits of ASD surgery to patients is warranted.Level of Evidence: 3., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Retrospective cohort study of a prospectively collected multi-center database of adult spinal deformity (ASD) patients., Objective: We hypothesized that patients undergoing ASD surgery with and without previous spinal cord stimulators (SCS)/ intrathecal medication pumps (ITP) would exhibit increased complication rates but comparable improvement in health-related quality of life., Summary of Background Data: ASD patients sometimes seek pain management with SCS or ITP before spinal deformity correction. Few studies have examined outcomes in this patient population., Methods: Patients undergoing ASD surgery and eligible for 2-year follow-up were included. Preoperative radiographs were reviewed for the presence of SCS/ITP. Outcomes included complications, Oswestry Disability Index (ODI), Short Form-36 Mental Component Score, and SRS-22r. Propensity score matching was utilized., Results: In total, of 1034 eligible ASD patients, a propensity score-matched cohort of 60 patients (30 with SCS/ITP, 30 controls) was developed. SCS/ITP were removed intraoperatively in most patients (56.7%, n = 17). The overall complication rate was 80.0% versus 76.7% for SCS/ITP versus control (P > 0.2), with similarly nonsignificant differences for intraoperative and infection complications (all P > 0.2). ODI was significantly higher among patients with SCS/ITP at baseline (59.2 vs. 47.6, P = 0.0057) and at 2-year follow-up (44.4 vs. 27.7, P = 0.0295). The magnitude of improvement, however, did not significantly differ (P = 0.45). Similar results were observed for SRS-22r pain domain. Satisfaction did not differ between groups at either baseline or follow-up (P > 0.2). No significant difference was observed in the proportion of patients with SCS/ITP versus control reaching minimal clinically important difference in ODI (47.6% vs. 60.9%, P = 0.38). Narcotic usage was more common among patients with SCS/ITP at both baseline and follow-up (P < 0.05)., Conclusion: ASD patients undergoing surgery with SCS/ITP exhibited worse preoperative and postoperative ODI and SRS-22r pain domain; however, the mean improvement in outcome scores was not significantly different from patients without stimulators or pumps. No significant differences in complications were observed between patients with versus without SCS/ITP.Level of Evidence: 3., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: With increasing interest in cost optimization, costs of adult spinal deformity (ASD) surgery intersections with frailty merit investigation., Objective: To investigate costs associated with ASD and frailty., Methods: Patients with ASD (scoliosis ≥20°, sagittal vertical axis [SVA] ≥5 cm, pelvic tilt ≥ 25°, or thoracic kyphosis ≥ 60°) with baseline and 2-yr radiographic data were included. Patients were severely frail (SF), frail (F), or not frail (NF). Utility data were converted from Oswestry Disability Index to Short-Form Six-Dimension. Quality-adjusted life years (QALYs) used 3% rate for decline to life expectancy. Costs were calculated using PearlDiver. Loss of work costs were based on SRS-22rQ9 and US Bureau of Labor Statistics. Accounting for complications, length of stay, revisions, and death, cost per QALY at 2 yr and life expectancy were calculated., Results: Five hundred ninety-two patients with ASD were included (59.8 ± 14.0 yr, 80% F, body mass index: 27.7 ± 6.0 kg/m2, Adult Spinal Deformity-Frailty Index: 3.3 ± 1.6, and Charlson Comorbidity Index: 1.8 ± 1.7). The average blood loss was 1569.3 mL, and the operative time was 376.6 min, with 63% undergoing osteotomy and 54% decompression. 69.3% had a posterior-only approach, 30% combined, and 0.7% anterior-only. 4.7% were SF, 22.3% F, and 73.0% NF. At baseline, 104 were unemployed losing $971.38 weekly. After 1 yr, 62 remained unemployed losing $50 508.64 yearly. With propensity score matching for baseline SVA, cost of ASD surgery at 2 yr for F/SF was greater than that for NF ($81 347 vs $69 722). Cost per QALY was higher for F/SF at 2 yr than that for NF ($436 473 vs $430 437). At life expectancy, cost per QALY differences became comparable ($58 965 vs $58 149)., Conclusion: Despite greater initial cost, F and SF patients show greater improvement. Cost per QALY for NF and F patients becomes similar at life expectancy., (Copyright © Congress of Neurological Surgeons 2021. All rights reserved.)

Objective: This retrospective cohort study aimed to develop a formal predictive model distinguishing between symptomatic and asymptomatic distal junctional kyphosis (DJK). In this study the authors identified a DJK rate of 32.2%. Predictive models were created that can be used with high reliability to help distinguish between severe symptomatic DJK and mild asymptomatic DJK through the use of surgical factors, radiographic parameters, and patient variables., Methods: Patients with cervical deformity (CD) were stratified into asymptomatic and symptomatic DJK groups. Symptomatic: 1) DJK angle (DJKA) > 10° and either reoperation due to DJK or > 1 new-onset neurological sequela related to DJK; or 2) either a DJKA > 20° or ∆DJKA > 20°. Asymptomatic: ∆DJK > 10° in the absence of neurological sequelae. Stepwise logistic regressions were used to identify factors associated with these types of DJK. Decision tree analysis established cutoffs., Results: A total of 99 patients with CD were included, with 32.2% developing DJK (34.3% asymptomatic, 65.7% symptomatic). A total of 37.5% of asymptomatic patients received a reoperation versus 62.5% symptomatic patients. Multivariate analysis identified independent baseline factors for developing symptomatic DJK as follows: pelvic incidence (OR 1.02); preoperative cervical flexibility (OR 1.04); and combined approach (OR 6.2). Having abnormal hyperkyphosis in the thoracic spine, more so than abnormal cervical lordosis, was a factor for developing symptomatic disease when analyzed against asymptomatic patients (OR 1.2). Predictive modeling identified factors that were predictive of symptomatic versus no DJK, as follows: myelopathy (modified Japanese Orthopaedic Association score 12-14); combined approach; uppermost instrumented vertebra C3 or C4; preoperative hypermobility; and > 7 levels fused (area under the curve 0.89). A predictive model for symptomatic versus asymptomatic disease (area under the curve 0.85) included being frail, T1 slope minus cervical lordosis > 20°, and a pelvic incidence > 46.3°. Controlling for baseline deformity and disability, symptomatic patients had a greater cervical sagittal vertical axis (4-8 cm: 47.6% vs 27%) and were more malaligned according to their Scoliosis Research Society sagittal vertical axis measurement (OR 0.1) than patients without DJK at 1 year (all p < 0.05). Despite their symptomatology and higher reoperation rate, outcomes equilibrated in the symptomatic cohort at 1 year following revision., Conclusions: Overall, 32.2% of patients with CD suffered from DJK. Symptomatic DJK can be predicted with high reliability. It can be further distinguished from asymptomatic occurrences by taking into account pelvic incidence and baseline cervicothoracic deformity severity.

Background: Preoperative opioid is associated with poor postoperative outcomes for several surgical specialties, including neurosurgical, orthopedic, and general surgery. Patients with symptomatic adult spinal deformity (SASD) are among the highest patient populations reporting opioid use prior to surgery. Surgery for SASD has been demonstrated to improve patient reported quality of life, however, little medical economic data exists evaluating impact of preoperative opioid use upon surgical cost-effectiveness for SASD. The purpose of this study was to evaluate the impact that preoperative opioid use has upon SASD surgery including duration of intensive care unit (ICU) and hospital stay, postoperative complications, patient reported outcome measures (PROMs), and surgical cost-effectiveness using a propensity score matched analysis model., Methods: Surgically treated SASD patients enrolled into a prospective multi-center SASD study were assessed for preoperative opioid use, and divided into two cohorts; preoperative opioid users (OPIOID) and preoperative opioid non-users (NON). Propensity score matching (PSM) was used to control for patient age, medical comorbidities, spine deformity type and magnitude, and surgical procedures for OPIOID vs NON. Preoperative and minimum 2-year postoperative PROMs, duration of ICU and hospital stay, postoperative complications, and opioid use at one and two years postoperative were compared for OPIOID vs NON. Preoperative, one year, and minimum two-year postoperative SF6D values were calculated, and one- and two-year postoperative QALYs were calculated using SF6D change from baseline. Hospital costs at the time of index surgery were calculated and cost/QALY compared at one and two years postop for OPIOID vs NON., Results: 261/357 patients (mean follow-up 3.3 years) eligible for study were evaluated. Following the PSM control, OPIOID (n=97) had similar preoperative demographics, smoking and depression history, spine deformity magnitude, and surgery performed as NON (n=164; p>0.05). Preoperatively, OPIOID reported greater NRS back pain (7.7 vs 6.7) and leg pain (5.2 vs 3.9), worse ODI (50.8 vs 36.9), worse SF-36 PCS (28.8 vs 35.6), and worse SRS-22r self-image (2.3 vs 2.5) than NON, respectively (p<0.05). OPIOID had longer ICU (41.2 vs 21.4 hours) and hospital stay (10.6 vs 8.0 days) than NON, respectively (p<0.05). At last postoperative follow up, OPIOID reported greater NRS back pain (4.1 vs 2.3) and leg pain (2.9 vs 1.7), worse ODI (32.4 vs 19.4), worse SF-36 PCS (37.4 vs 47.0), worse SRS-22r self-image (3.5 vs 4.0), and lower SRS-22r treatment satisfaction score (2.5 vs 4.5) than NON, respectively (p<0.05). At last follow-up postoperative Cost/QALY was higher for OPIOID ($44,558.31) vs NON ($34,304.36; p<0.05). At last follow up OPIOID reported greater postoperative opioid usage than NON [41.2% vs. 12.9%, respectively; odds ratio =4.7 (95% CI=2.6-8.7; p<0.05)]., Conclusions: Prospective, multi-center, matched analysis demonstrated SASD patients using opioids prior to SASD surgery reported worse preoperative and postoperative quality of life, had longer ICU and hospital stay, had less cost effectiveness of SASD surgery. Preoperative opioid users also reported lower treatment satisfaction, and reported greater postoperative opioid use than non-users. These data should be used to council patients on the negative impact preoperative opioid use can have on SASD surgery., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors. Published by Elsevier Ltd on behalf of North American Spine Society.)

Study Design: Retrospective cohort study., Objective: The aim of this study was to investigate the impact of cervical to thoracolumbar ratios on poor outcomes in cervical deformity (CD) corrective surgery., Summary of Background Data: Consideration of distal regional and global alignment is a critical determinant of outcomes in CD surgery. For operative CD patients, it is unknown whether certain thoracolumbar parameters play a significant role in poor outcomes and whether addressing such parameters is warranted., Methods: Included: surgical CD patients (C2-C7 Cobb >10°, cervical lordosis [CL] >10°, C2-C7 sagittal vertical axis (cSVA) >4 cm, or chin-brow vertical angle >25°) with baseline and 1-year data. Patients were assessed for ratios of preop cervical and global parameters including: C2 Slope/T1 slope, T1 slope minus C2-C7 lordosis (TS-CL)/mismatch between pelvic incidence and lumbar lordosis (PI-LL), cSVA/sagittal vertical axis (SVA). Deformity classification ratios of cervical (Ames-ISSG) to spinopelvic (SRS-Schwab) were investigated: cSVA modifier/SVA modifier, TS-CL modifier/PI-LL modifier. Cervical to thoracic ratios included C2-C7 lordosis/T4-T12 kyphosis. Correlations assessed the relationship between ratios and poor outcomes (major complication, reoperation, distal junctional kyphosis (DJK), or failure to meet minimal clinically important difference [MCID]). Decision tree analysis through multiple iterations of multivariate regressions assessed cut-offs for ratios for acquiring suboptimal outcomes., Results: A total of 110 CD patients were included (61.5 years, 66% F, 28.8 kg/m2). Mean preoperative radiographic ratios calculated: C2 slope/T1 slope of 1.56, TS-CL/PI-LL of 11.1, cSVA/SVA of 5.4, CL/thoracic kyphosis (TK) of 0.26. Ames-ISSG and SRS-Schwab modifier ratios: cSVA/SVA of 0.1 and TS-CL/PI-LL of 0.35. Pearson correlations demonstrated a relationship between major complications and baseline TS-CL/PI-LL, Ames TS-CL/Schwab PI-LL modifiers, and the CL/TK ratios (P < 0.050). Reoperation had significant correlation with TS-CL/PI-LL and cSVA/SVA ratios. Postoperative DJK correlated with C2 slope/T1 slope and CL/TK ratios. Not meeting MCID for Neck Disability Index (NDI) correlated with CL/TK ratio and not meeting MCID for EQ5D correlated with Ames TS-CL/Schwab PI-LL., Conclusion: Consideration of cervical to global alignment is a critical determinant of outcomes in CD corrective surgery. Key ratios of cervical to global alignment correlate with suboptimal clinical outcomes. A larger cervical lordosis to TK predicted postoperative complication, DJK, and not meeting MCID for NDI.Level of Evidence: 4., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The objective of the study is to investigate which neurologic complications affect clinical outcomes the most following cervical deformity (CD) surgery., Methods: CD patients (C2-C7 Cobb >10°, CL >10°, cSVA >4 cm or chin-brow vertical angle >25°) >18 years with follow-up surgical and health-related quality of life (HRQL) data were included. Descriptive analyses assessed demographics. Neurologic complications assessed were C5 motor deficit, central neurodeficit, nerve root motor deficits, nerve sensory deficits, radiculopathy, and spinal cord deficits. Neurologic complications were classified as major or minor, then: intraoperative, before discharge, before 30 days, before 90 days, and after 90 days. HRQL outcomes were assessed at 3 months, 6 months, and 1 year. Integrated health state (IHS) for the neck disability index (NDI), EQ5D, and modified Japanese Orthopaedic Association (mJOA) were assessed using all follow-up time points. A subanalysis assessed IHS outcomes for patients with 2Y follow-up., Results: 153 operative CD patients were included. Baseline characteristics: 61 years old, 63% female, body mass index 29.7, operative time 531.6 ± 275.5, estimated blood loss 924.2 ± 729.5, 49% posterior approach, 18% anterior approach, 33% combined. 18% of patients experienced a total of 28 neurologic complications in the postoperative period (15 major). There were 7 radiculopathy, 6 motor deficits, 6 sensory deficits, 5 C5 motor deficits, 2 central neurodeficits, and 2 spinal cord deficits. 11.2% of patients experienced neurologic complications before 30 days (7 major) and 15% before 90 days (12 major). 12% of neurocomplication patients went on to have revision surgery within 6 months and 18% within 2 years. Neurologic complication patients had worse mJOA IHS scores at 1Y but no significant differences between NDI and EQ5D (0.003 vs. 0.873, 0.458). When assessing individual complications, central neurologic deficits and spinal cord deficit patients had the worst outcomes at 1Y (2.6 and 1.8 times worse NDI scores, P = 0.04, no improvement in EQ5D, 8% decrease in EQ5D). Patients with sensory deficits had the best NDI and EQ5D outcomes at 1Y (31% decrease in NDI, 8% increase in EQ5D). In a subanalysis, neurologic patients trended toward worse NDI and mJOA IHS outcomes ( P = 0.263, 0.163)., Conclusions: 18% of patients undergoing CD surgery experienced a neurologic complication, with 15% within 3 months. Patients who experienced any neurologic complication had worse mJOA recovery kinetics by 1 year and trended toward worse recovery at 2 years. Of the neurologic complications, central neurologic deficits and spinal cord deficits were the most detrimental., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Journal of Craniovertebral Junction and Spine.)

Purpose: AI algorithms have shown promise in medical image analysis. Previous studies of ASD clusters have analyzed alignment metrics-this study sought to complement these efforts by analyzing images of sagittal anatomical spinopelvic landmarks. We hypothesized that an AI algorithm would cluster preoperative lateral radiographs into groups with distinct morphology., Methods: This was a retrospective review of a multicenter, prospectively collected database of adult spinal deformity. A total of 915 patients with adult spinal deformity and preoperative lateral radiographs were included. A 2 × 3, self-organizing map-a form of artificial neural network frequently employed in unsupervised classification tasks-was developed. The mean spine shape was plotted for each of the six clusters. Alignment, surgical characteristics, and outcomes were compared., Results: Qualitatively, clusters C and D exhibited only mild sagittal plane deformity. Clusters B, E, and F, however, exhibited marked positive sagittal balance and loss of lumbar lordosis. Cluster A had mixed characteristics, likely representing compensated deformity. Patients in clusters B, E, and F disproportionately underwent 3-CO. PJK and PJF were particularly prevalent among clusters A and E. Among clusters B and F, patients who experienced PJK had significantly greater positive sagittal balance than those who did not., Conclusions: This study clustered preoperative lateral radiographs of ASD patients into groups with highly distinct overall spinal morphology and association with sagittal alignment parameters, baseline HRQOL, and surgical characteristics. The relationship between SVA and PJK differed by cluster. This study represents significant progress toward incorporation of computer vision into clinically relevant classification systems in adult spinal deformity., Level of Evidence Iv: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)