Search

Background: Kyphotic spinal deformity is a complication of ankylosing spondylitis (AS). In rare cases, particularly in obese patients, the deformity might extend to the cervicothoracic spine, resulting in a severe "chin-on-abdomen" deformity. This condition severely impairs quality of life by affecting gaze, swallowing, and causing chronic pain. While corrective surgery is often performed for lumbar and thoracic kyphosis, cases involving global kyphotic deformities are less common., Observations: The authors present the case of a 66-year-old obese man with AS and a chin-on-abdomen deformity. Prone positioning for surgery was not feasible due to his body habitus. A three-stage corrective surgery was performed: a C7 extension osteotomy in a semisitting position, an L3 pedicle subtraction osteotomy in the lateral decubitus position, and a T11 vertebral column resection in the prone position. The first stage utilized a seldom-used, earlier osteotomy technique with modern instrumentation and neuromonitoring. Obesity again precluded prone positioning in the second stage, necessitating surgery in the lateral position. Postoperatively, the patient exhibited significant postural improvement, maintained over a 5-year follow-up period., Lessons: This case underscores the importance of adaptable techniques and positioning strategies in correcting complex spinal deformities in obese patients with AS. Integrating traditional methods with modern technology is crucial for achieving successful outcomes. https://thejns.org/doi/10.3171/CASE24664.

Objective: Many studies have compared outcomes following anterior and posterior cervical fusion, yet the differences in the impacts of perioperative complications on outcomes have not been well studied. This study aimed to assess the differences in the effects of 30-day perioperative complications on patient-reported outcome measures (PROMs) after multilevel anterior versus posterior cervical fusion., Methods: Adult patients who underwent anterior or posterior cervical fusion at three or more levels between 2014 and 2020 were analyzed. Each group was subdivided based on the occurrence and severity of perioperative complication: no complication versus minor complication versus major complication. The study primarily compared PROMs and minimal clinically important differences (MCIDs) within and between the groups., Results: A total of 146 anterior (102 with no complications, 36 with minor complications, 8 with major complications) and 55 posterior (36 with no complications, 13 with minor complications, 6 with major complications) cervical fusion cases were analyzed. Within the anterior or posterior group, there were no significant differences in the PROM change or proportions of patients achieving the MCID. In comparing the anterior group with the posterior group, anterior patients without complications had better improvement in the 3-month Neck Disability Index (coefficient 11.2, p = 0.019), with higher odds of achieving the MCID for the modified Japanese Orthopaedic Association score at 3 months (OR 2.0, p = 0.039). Otherwise, there were no significant differences in the PROM change or proportions of patients achieving the MCID in subsets of anterior or posterior patients with minor or major complications. Furthermore, patients with major complications had higher early readmission rates regardless of the surgical approach. Major complications were also associated with longer and increased rates of intensive care unit stays after posterior fusion compared with anterior fusion., Conclusions: This study suggests that the severity of perioperative complications following anterior or posterior cervical fusion did not predict changes in PROMs or achievement of MCIDs in the anterior or posterior group. Also, PROMs may not fully differentiate the full extent of the impact of perioperative complications following anterior versus posterior cervical fusion. Otherwise, in subsets of patients without complications, anterior compared with posterior patients had improved Neck Disability Index scores at 3 months, with a significant proportion of patients achieving the MCID for the modified Japanese Orthopaedic Association score at 3 months.

Objective: This study evaluates the impact of L4-L5 minimally invasive surgery (MIS)- transforaminal lumbar interbody fusion (TLIF) on adjacent-level parameters., Methods: This is a retrospective study performed on consecutive patients between January 2015 and December 2019. The index- and adjacent-level segmental lordosis (SL) and disc angle (DA) were measured. Patient-reported outcomes (PROs) were collected preoperatively and at 3-24 months postoperatively. Factors influencing changes in adjacent-level parameters and the occurrence of adjacent segment degeneration (ASDeg) were assessed., Results: A total of 117 adult patients, averaging 65.5 years of age and slight preponderance of female (56.4%), were analyzed. L4-L5 SL decreased at 2 years (P < 0.05), but L4-L5 DA significantly increased at all timepoints (P < 0.05). While L3-L4 SL and DA significantly decreased at all timepoints (P < 0.05), L5-S1 SL decreased at 3 and 12 months (P < 0.05) and L5-S1 DA only significantly decreased at 2 years (P < 0.05). All PROs improved significantly (P < 0.0001). The ASDeg rate was 19.7% at 2.2 years. Cephalad and caudal ASDeg rates were 12.0% and 10.3%, respectively. Eight patients (6.8%) required adjacent-level reoperations, mainly at L3-L4 (6 cases). The use of expandable cage significantly reduced the odds of caudal ASDeg (OR 0.15, P = 0.037), but had no significant effect on cephalad ASDeg., Conclusions: L4-L5 MIS-TLIF had a more consistent effect on L3-L4 than L5-S1. Although adjacent-level SL and DA decreased over time, their association with ASDeg appears limited, suggesting a multifactorial etiology. L4-L5 MIS-TLIF provides demonstrable clinical benefits with lasting PRO improvements and low adjacent-level reoperations., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Spinal deformity as a sequela of nontuberculous spondylodiscitis is a rarely discussed clinical entity. Sagittal plane deformity, segmental instability, and persistently active infection overlap in these patients resulting in severe restriction in activity and quality of life. The presence of multiple medical co-morbidities restricts surgical options but nonoperative care may be ineffective and result in persistent, refractory discitis for years. We describe our experience with vertebrectomy and long-segment fixation for patients with postinfectious thoracic or lumbar deformity., Methods: A retrospective chart review of 23 consecutive patients who underwent vertebrectomy and long-segment fixation for thoracic or lumbar deformity secondary to nontuberculous bacterial spondylodiscitis was performed. Pre, peri- and postoperative data is compiled and analyzed with a focus on the perioperative management algorithm to safely perform an extensive reconstruction in this very sick patient population., Results: Extremely low preoperative quality of life was evident with 87% (20/23) of patients bedridden primarily due to pain despite 70% (16/23) of patients being strong enough to ambulate (Frankel D or E). Most patients (87%) already had an identified infection under adequate treatment either through blood cultures, prior biopsy or decompressive surgery. A single-stage posterior-only was the primary surgical approach utilized in the majority (83%) of cases. Complications were present in 100% of patients, most commonly perioperative anemia and hypotension requiring vasopressor support and aggressive blood product replacement. One in-hospital mortality occurred secondarily to pulmonary embolism. Mean preoperative segmental angle was 18±10 degrees of kyphosis which was corrected to 1±9 degrees of lordosis (p=.001). The mean correction of the segmental angle was 19 degrees (standard deviation 23 degrees). Visual analogue scale scores improved from a preoperative value of 8.8±0.9 to a postoperative value of 2.5±1.4 (p<.001), which was obtained at the last outpatient follow-up (mean 631 days after surgery). Full self-care including ambulation was achieved in 18/23 (78%) patients, and the infection was successfully treated in 22/23 (96%) patients after long-term antibiotics., Conclusions: Patients with refractory spondylodiscitis on appropriate care and antibiotics are typically considered extremely poor surgical candidates despite nonoperative care often being ineffective. Postinfectious deformity may also be so severe as to preclude a limited surgical treatment strategy. This study suggests that extensive circumferential reconstruction for deformity secondary to bacterial spondylodiscitis can be effective in restoring these extremely sick patients to self-care and ambulatory status., Competing Interests: One or more authors declare potential competing financial interests or personal relationships as specified on required ICMJE-NASSJ Disclosure Forms., (© 2024 The Author(s).)

Background and Objectives: Studies have demonstrated increased risk of adjacent segment disease (ASD) after open fusion with adjacent-level laminectomy, with rates ranging from 16%-47%, potentially related to disruption of the posterior ligamentous complex. Minimally invasive surgical (MIS) approaches may offer a more durable result. We report institutional outcomes of simultaneous MIS transforaminal lumbar interbody fusion (MISTLIF) and adjacent-level laminectomy for patients with low grade spondylolisthesis and ASD., Methods: Retrospective analysis was performed on patients who underwent MISTLIF with adjacent level laminectomy to treat grade I-II spondylolisthesis with adjacent stenosis at a single institution from 2007-2022., Results: A total of 34 patients met criteria, with mean follow-up of 23.1 months. In total, 37 levels were fused and 45 laminectomies performed. In this group, 21 patients received a single level laminectomy and single-level MISTLIF, 10 patients received a 2-level laminectomy and single-level MISTLIF, 2 patients received a single-level laminectomy and 2-level MISTLIF, and 1 patient received a 2-level laminectomy and 2-level MISTLIF. Three (8.8%) patients experienced clinically significant postoperative ASD requiring reoperation. Three other patients required reoperation for other reasons. Multiple logistic regression did not reveal any association between development of ASD and surgical covariates., Conclusion: MISTLIF with adjacent-level laminectomy demonstrated a favorable safety profile with rates of postoperative ASD lower than published rates after open fusion and on par with the published rates of ASD from MISTLIF alone. Future prospective studies may better elucidate the durability of adjacent-level laminectomies when performed alongside MISTLIF, but retrospective data suggests it is safe and durable., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background and Objectives: In 2013, all neurosurgery programs were mandated to adopt a 7-year structure. We sought to characterize how programs use the seventh year of training (postgraduate year 7 [PGY7])., Methods: We surveyed all accredited neurosurgery programs in the United States regarding the PGY7 residents' primary role and the availability of enfolded fellowships. We compiled responses from different individuals in each program: chair, program director, program coordinator, and current chiefs., Results: Of 120 accredited neurological surgery residency programs within the United States, 91 (76%) submitted responses. At these programs, the primary roles of the PGY7 were chief of service (COS, 71%), enfolded fellowships (EFF, 18%), transition to practice (10%), and elective time (1%). Most residencies have been 7-year programs for >10 years (52, 57%). Sixty-seven programs stated that they offer some form of EFF (73.6%). The most common EFFs were endovascular (57, 62.6%), spine (49, 53.9%), critical care (41, 45.1%), and functional (37, 40.7%). These were also the most common specialties listed as Committee on Advanced Subspecialty Training accredited by survey respondents. Spine and endovascular EFFs were most likely to be restricted to PGY7 (24.2% and 23.1%, respectively), followed by neuro-oncology (12, 13.2%). The most common EFFs reported as Committee on Advanced Subspecialty Training accredited but not restricted to PGY7 were endovascular (24, 26.4%) and critical care (23, 25.3%)., Conclusion: Most accredited neurological surgery training programs use the COS as the primary PGY7 role. Programs younger in their PGY7 structure seem to maintain the traditional COS role. Those more established seem to be experimenting with various roles the PGY7 year can fill, including enfolded fellowships and transition-to-practice years, predominantly. Most programs offer some form of enfolded fellowship. This serves as a basis for characterization of how neurological surgery training may develop in years to come., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Objective: Postoperative C5 palsy (C5P) is a known complication in cervical spine surgery. However, its exact pathophysiology is unclear. The authors aimed to provide a review of the current understanding of C5P by performing a comprehensive, systematic review of the existing literature and conducting a critical appraisal of existing evidence to determine the risk factors of C5P., Methods: A systematic search of PubMed/MEDLINE (January 1, 2019, to July 2, 2021), EMBASE (inception to July 2, 2021), and Cochrane (inception to July 2, 2021) databases was conducted. Preestablished criteria were used to evaluate studies for inclusion. Studies that adjusted for one or more of the following factors were considered: preoperative foraminal diameter (FD) at C4/5, posterior spinal cord shift at C4/5, preoperative anterior-posterior diameter (APD) at C4/5, preoperative spinal cord rotation, and change in C2-7 Cobb angle. Studies were rated as good, fair, or poor based on the Quality in Prognosis Studies (QUIPS) tool. Random effects meta-analyses were done using methods outlined by Cochrane methodologists for pooling of prognostic studies. Overall quality (strength) of evidence was based on Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methods for prognostic studies. The protocol for this review was published on the PROSPERO (CRD264358) website., Results: Of 303 potentially relevant citations of studies, 12 met the inclusion criteria set a priori. These works provide moderate-quality evidence that preoperative FD substantially increases the odds of C5P in patients undergoing posterior cervical surgery. Pooled estimates across 7 studies in which various surgical approaches were used indicate that the odds of C5P approximately triple for each millimeter decrease in preoperative FD (OR 3.05, 95% CI 2.07-4.49). Preoperative APD increases the odds of C5P, but the confidence is low. Across 3 studies, each using different surgical approaches, each millimeter decrease in preoperative APD was associated with a more than 2-fold increased odds of C5P (pooled OR 2.51, 95% CI 1.69-3.73). Confidence that there is an association with postoperative C5P and posterior spinal cord shift, change in sagittal Cobb angle, and preoperative spinal cord rotation is very low., Conclusions: The exact pathophysiological process resulting in postoperative C5P remains an enigma but there is a clear association with foraminal stenosis, especially when performing posterior procedures. C5P is also related to decreased APD but the association is less clear. The overall quality (strength) of evidence provided by the current literature is low to very low for most factors. Systematic review registration no.: CRD264358 (https://www.crd.york.ac.uk/prospero/).

Background: Although published data support the utilization of circumferential fusion to treat select cervical spine pathologies, it is unclear whether the posterior-anterior-posterior (PAP) fusion has increased risks compared with the anterior-posterior fusion., Objective: To evaluate the differences in perioperative complications between the 2 circumferential cervical fusion approaches., Methods: One hundred fifty-three consecutive adult patients who underwent single-staged circumferential cervical fusion for degenerative pathologies from 2010 to 2021 were retrospectively reviewed. Patients were stratified into the anterior-posterior ( n = 116) and PAP ( n = 37) groups. The primary outcomes assessed were major complications, reoperation, and readmission., Results: Although the PAP group was older ( P = .024), predominantly female ( P = .024), with higher baseline neck disability index ( P = .026), cervical sagittal vertical axis ( P = .001), and previous cervical operation rate ( P < .00001), the major complication, reoperation, and readmission rates were not significantly different from the 360° group. Although the PAP group had higher urinary tract infection ( P = .043) and transfusion ( P = .007) rates, higher estimated blood loss ( P = .034), and longer operative times ( P < .00001), these differences were insignificant after the multivariable analysis. Overall, operative time was associated with older age (odds ratio [OR] 17.72, P = .042), atrial fibrillation (OR 158.30, P = .045), previous cervical operation (OR 5.05, P = .051), and lower baseline C1 - 7 lordosis (OR 0.93, P = .007). Higher estimated blood loss was associated with older age (OR 1.13, P = .005), male gender (OR 323.31, P = .047), and higher baseline cervical sagittal vertical axis (OR 9.65, P = .022)., Conclusion: Despite some differences in preoperative and intraoperative variables, this study suggests both circumferential approaches have comparable reoperation, readmission, and complication profiles, all of which are high., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Background: Nonunion remains a concern in multilevel anterior cervical discectomy and fusion (ACDF), yet there are limited data on nonunion after 4 to 5-level ACDF. In fact, the largest series on 4-level or 5-level ACDF focused specifically on the swallowing outcomes., Objective: To assess nonunion after 4 to 5-level ACDF., Methods: Forty-one patients treated with 4 to 5-level ACDF with minimum of 12-month radiographic follow-up were retrospectively reviewed. Nonunion was found in 25 patients (61%) and 42 levels (25%) and complete fusion in 16 (39%) patients and 126 levels (75%). The 2 groups were further compared., Results: One-level nonunion was by far the most common pattern compared with multilevel nonunion. Nonunion occurred more frequently at the caudal than the cranial or middle segments ( P < .0001). There were significantly more subsidence ( P < .0001) and screw fractures/pullouts ( P < .0001) in the nonunion compared with the fusion group. The symptomatic patients were significantly younger than the asymptomatic patients ( P = .044). The symptomatic levels were significantly more than asymptomatic levels ( P = .048). Equal proportion of patients implanted with allograft and polyetheretherketone had nonunion. However, there were markedly more nonunion than fused levels with allograft and more fused than nonunion levels with polyetheretherketone ( P = .023). The reoperation rate was 24.4% and mostly due to nonunion. There were no reoperations within 90 days of the primary surgery., Conclusion: The nonunion rate for 4-level and 5-level ACDF may be higher than previously reported. Symptomatic nonunion remains a major reason for reoperation after multilevel ACDF. Baseline characteristics that negatively affect fusion may be obviated by careful patient selection., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Objective: There are limited patient-reported outcome measure (PROM) data on 4-level and 5-level anterior cervical discectomy and fusion (ACDF). The largest series to date solely focused on complications. This retrospective series evaluates PROMs after 4-level and 5-level ACDF., Methods: Pertinent data from adult patients treated with a 4-level or 5-level ACDF in 2011-2019 were analyzed. PROMs and minimal clinically important differences (MCIDs) were assessed. Factors associated with favorable and unfavorable outcomes were identified., Results: There were 34 patients (30 underwent 4-level and 4 underwent 5-level ACDFs) with a mean age of 59.6 years; 55.9% were women. At 3 months, there were significant improvements in PROMs except Short-Form 12-Item Survey (SF-12) mental component subscale, which showed modest improvement. At 12 months, there were significant improvements in PROMs except SF-12 physical component subscale (PCS), which showed moderate improvement. The proportions of patients who met the MCID cutoffs ranged from 35.3% (numeric rating scale [NRS]-neck) to 75% (Veteran RAND 12-Item Survey [VR-12] PCS) at 3 months and 38.2% (NRS-arm) to 65.5% (VR-12 mental component subscale) at 12 months. Shorter symptom duration was associated with significantly reduced postoperative pain and Neck Disability Index scores. Shorter length of stay was associated with significantly improved postoperative functional outcomes. patients undergoing 4-level compared with 5-level ACDF achieved better postoperative PROMs. Shorter procedure duration was associated with improved PROMs at 3 months. No patient returned to the operating room within 30 days. Patients who required reoperation achieved significantly inferior Neck Disability Index, NRS-neck, and SF-12 PCS scores at 3 months., Conclusions: This study showed satisfactory PROMs up to 12 months after 4-level and 5-level ACDF despite the complication rate. With thorough preoperative planning and meticulous technique, performing this procedure in carefully selected patients may be associated with acceptable PROMs., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to evaluate the outcomes of elderly patients with type 2 odontoid fractures treated with an instrumented posterior fusion., Methods: Ninety-three consecutive patients older than 65 years of age in whom a type 2 odontoid fracture had been treated with a variety of C1-2 posterior screw fixation techniques were retrospectively reviewed., Results: The average age was 78 years (range 65-95 years). Thirty-seven patients had an additional fracture, 30 of which involved C1. Three patients had cervical spinal cord dysfunction due to their injury. All patients had comorbidities. The average total hospitalization was 9.6 days (range 2-37 days). There were 3 deaths and 19 major complications, the most common of which was pneumonia. No patient suffered a vertebral artery injury. Imaging studies were obtained in 64 patients at least 12 months postsurgery (mean 19 months). Fusion was assessed by dynamic radiographs in all cases and with a CT scan in 80% of the cases. Four of the 64 patients did not achieve fusion (6.25% overall). All patients in whom fusion failed had undergone C1 lateral mass fixation and C2 pars (1/29, 3.4%) or laminar (3/9, 33.3%) fixation., Conclusions: Instrumented posterior cervical fusions may be performed in elderly patients with acceptable morbidity and mortality. The fusion rate is excellent except when bilateral C2 translaminar screws are used for axis fixation.

Objective: The modified frailty index (mFI) is a simple tool that measures physiological reserve based on a thorough history and physical examination. Its use has been validated in several surgical specialties, including spinal deformity surgery. Prior research has suggested no significant differences in clinical outcomes between elderly and nonelderly patients undergoing posterior lumbar interbody fusion. The authors sought to investigate the use of the mFI in patients undergoing transforaminal lumbar interbody fusion (TLIF) and the relationship between frailty scores and clinical outcomes., Methods: A retrospective chart review was conducted on 198 patients who underwent a single-level TLIF over a 60-month period at a single institution. For all patients, an mFI score was computed incorporating a set of 11 clinical factors to assess preexisting comorbidities and functional status. Clinical follow-up and health-related quality-of-life (HRQOL) scores were obtained at baseline and regular intervals of 6 weeks, 6 months, and 1 year following surgery., Results: Patients were grouped according to their level of frailty: no frailty (mFI = 0), mild frailty (mFI = 0.09), moderate frailty (mFI = 0.18), and severe frailty (mFI ≥ 0.27). One-way ANOVA revealed increasing levels of frailty to be associated with an increased rate of complications, from 10.3% to 63.6%. In addition, increasing levels of frailty were associated with longer hospital length of stay (LOS), from 3.1 days to 6.5 days, and lower rates of disposition to home. At the 1-year follow-up, increased levels of frailty were associated with worse HRQOL measures., Conclusions: Increasing mFI score was associated with higher morbidity, longer inpatient LOS, and a lower probability of discharge to home in patients undergoing single-level TLIF. Consideration of the mFI may help surgeons improve decision-making across the spectrum of patients who are at risk from frailty.

Background: Single-level lumbar degenerative disc disease (DDD) remains a significant cause of morbidity in adulthood. Anterior lumbar interbody fusion (ALIF) and Transforaminal lumbar interbody fusion (TLIF) are surgical techniques developed to treat this condition. With limited studies on intermediate term outcomes in a single cohort, we compare radiographic and clinical outcomes in patients undergoing ALIF and TLIF., Methods: A retrospective chart review was performed on 164 patients (111 TLIF; 53 ALIF) over a 60-month period. X-ray radiographs obtained pre-operatively, prior to discharge, and at one year were utilized for radiographic assessment. Segmental lordosis, lumbar lordosis and HRQOL scores were measured preoperatively and at one-year timepoints., Results: Changes in lumbar lordosis and segmental lordosis were significantly greater after ALIF (4.6° vs. -0.6°, P=0.05; 4.7° vs. -0.7°, P<0.05) at one year (mean time, 366±20 days). At one year or greater, there was a greater reduction in mean VAS-leg score in TLIF patients (3.4 vs. 0.6, P<0.05) and ODI score (16.2 vs. 5.4, P<0.05). Similar outcomes were seen for VAS-back, SF-12 Physical Health, and SRS-30 Function/Activity. SF-12 Mental Health scores were found to be lower in patients undergoing TLIF (-3.5 vs. 2.7, P<0.05)., Conclusions: ALIF demonstrated a superior method of increasing lumbar and segmental lordosis. TLIF was utilized more in patients with higher pre-operative VAS-leg pain scores and therefore, showed a greater magnitude of VAS-leg pain improvement. TLIF also demonstrated a greater improvement in ODI scores despite similar baseline scores, suggesting a possible enhanced functional outcome., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/jss-20-673). The authors have no conflicts of interest to declare., (2021 Journal of Spine Surgery. All rights reserved.)

Background: Lateral lumbar interbody fusion (LLIF) affords a wide operative corridor to allow for a large interbody cage implantation for segmental reconstruction. There is a paucity of data describing segmental lordosis (SL) achieved with lordotic implants of varying angles. Here we compare changes in SL and lumbar lordosis (LL) after implantation of 6°, 10°, and 12° cages., Methods: We retrospectively reviewed LLIF cases over a 5.5-year period. We derived SL and LL using the standard cobb angle measurement from a standing lateral radiograph. We analyzed mean changes in SL and LL over time using the linear mixed effect model to estimate these longitudinal changes., Results: The most frequently treated level was L3-4, followed by L4-5. Significant increases in mean SL were found at each follow-up time point for all the cohorts. In an intercohort comparison, the mean changes in SL at immediate postoperative and last follow-up were significantly greater in the 10° cohort than 6° ([7.4° versus 3.1°, P = .004], [6.1° versus 2.3°, P = .025] respectively). The 12° cohort had higher mean change in SL at last follow-up than the 6° cohort (5.9° versus 2.3°, P = .022). There was no difference in mean change in SL between the 10° and 12° cohorts. No difference in overall mean LL over time was found. In terms of mean change in LL, no difference was observed except at immediate and 6-month postoperative in the 10° cohort ([9.6°, P = .001], [8.5, P = .003] respectively). By comparing mean change in LL, no difference existed except between the 10° and 6° immediately after surgery (9.6° versus 0.2°, P = .006)., Conclusions: LLIF cages significantly improve SL at the index level. However, this increase in SL is greater for 10° and 12° cages than the standard 6° cage. Use of 10° cages also resulted in overall improved LL than 6° cages., Level of Evidence: 3., Clinical Relevance: Lateral lumbar interbody fusion., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2021 ISASS.)

Background: Opioid requirements in the perioperative period in patients undergoing lumbar spine fusion surgery remain problematic. Although minimally invasive surgery (MIS) techniques have been developed, there still remain substantial challenges to reducing length of hospital stay (LOS) because of postoperative opioid requirements., Objective: To study the effect of implementing an enhanced recovery after surgery (ERAS) pathway in patients undergoing a 1-level MIS transforaminal lumbar interbody fusion (MIS TLIF) at our institution., Methods: We implemented an ERAS pathway in patients undergoing an elective single-level MIS TLIF for degenerative changes at a single institution. Consecutive patients were enrolled over a 20-mo period and compared with a pre-ERAS group prior to the implementation of the ERAS protocol. The primary outcome was LOS. Secondary outcomes included reduction in morphine milligram equivalent units (MME), pain scores, postoperative urinary retention (POUR), and incidence of postoperative delirium. Patients were compared using the chi-square and Welch's 2-sample t-tests., Results: A total of 299 patients were evaluated in this study: 87 in the ERAS group and 212 in the pre-ERAS group. In the ERAS group, there was a significant reduction in LOS (3.13 ± 1.53 vs 3.71 ± 2.07 d, P = .019), total admission MME (252.74 ± 317.38 vs 455.91 ± 498.78 MME, P = .001), and the number of patients with POUR (48.3% vs 65.6%, P = .008). There were no differences in pain scores., Conclusion: This is the largest ERAS MIS fusion cohort published to date evaluating a single cohort of patients in a generalizable manner. This ERAS pathway has shown a substantial decrease in LOS and opioid requirements in the immediate perioperative and postoperative period. There is further work to be done to evaluate patients undergoing other complex spine surgical interventions., (© Congress of Neurological Surgeons 2021.)

Objective: Airway obstruction after postoperative extubation is a dreaded but uncommon complication in patients undergoing circumferential cervical spine surgery (CCSS). The cuff leak test (CLT) has been utilized to assess air leak around the endotracheal tube which may reflect airway swelling. In this prospective observational study, we analyze the temporal evolution of CLT and perioperative factors that may influence it., Methods: Twenty patients undergoing single-stage CCSS were managed according to our extubation protocol. Patients were maintained intubated overnight following surgery. They were extubated if a CLT > 200 mL and both intensive care unit (ICU) and Neurosurgery teams agreed that it was safe. Patients extubated in the first postoperative day (8 of 20) comprised the early group, and the remaining patients (12 of 20) the delayed group. Patient and operative data were analyzed as a single group and comparing both groups., Results: The main indication for surgery was cervical deformity. Median number of levels fused was 5 anteriorly (range, 1-6) and 6 (range, 1-13) posteriorly. Patients were kept intubated for an average of 73.6 hours (range, 26-222 hours) and stayed in the ICU for 119.1 hours (range, 36-360 hours). There were 4 failed extubations and 3 patients (15%) required a tracheostomy. Patient profiles between both groups were very similar across most patient variables but differed significantly regarding infraglottic luminal area (p < 0.05). Patients with larger preoperative cuff leak values tended to have a shorter intubation period (p = 0.053)., Conclusion: This study objectively demonstrates the difficulties in airway management following CCSS and provides useful insight for preoperative planning and counseling. Local anatomic factors influence airway outcome more than operative factors. The study format does not allow for testing of interventions but we suggest that patients with favorable anatomy (larger infraglottic luminal area) may benefit from a less strict airway management protocol.

Cervical deformity, particularly kyphosis, is frequently encountered in surgical practice. While many cases are asymptomatic, some patients may have significant pain and disability. We provide a brief review of the pathophysiology of cervical deformity and the technical aspects of deformity correction in the cervical spine. Anterior techniques reviewed here include anterior cervical discectomy and fusion (ACDF), anterior corpectomy and fusion (ACCF) and anterior osteotomy (ATO). Posterior techniques include laminectomy and fusion, posterior column osteotomy (PCO) and pedicle subtraction osteotomy (PSO). This is a fast-evolving field as our understanding of cervical deformity matures and longer-term surgical outcomes are available., Competing Interests: Conflicts of Interest: The series “Advanced Techniques in Complex Cervical Spine Surgery” was commissioned by the editorial office without any funding or sponsorship. The authors have no conflicts of interest to declare., (2020 Journal of Spine Surgery. All rights reserved.)

Intervertebral disc (IVD) degeneration is a remodeling process mediated by several growth factors and cytokines. This process has been extensively studied in vitro and with pathologic specimens obtained during surgery for scoliosis or back pain. However, the occurrence and temporal evolution of these molecules during normal aging, particularly in the cervical segment, is not known. Our objective was to study and compare the presence of putative mediators in the IVD of young (<35 years, G1) and elderly (>65 years, G2) presumably asymptomatic individuals. Thirty C4-5 and C5-6 discs and thirty L4-5 and L5-S1 discs per group were collected during the autopsy of individuals whose family members denied a history of neck or back pain. Discs were divided into anterior, central (lumbar only) and posterior sectors for analysis. Immunohistochemistry for TNF-α, IL-1β, VEGF, NGF-β, BDNF, TIMP-1, MMP-1, -2 and -3 was performed and reactivity compared between groups and sectors. All of these molecules were detected in every disc sector of both G1 and G2. Most statistical comparisons (25/45, 55.6%) revealed an increase in mediator expression in G2 in relation to G1. Regional differences in the expression of remodeling enzymes were rare; NGF-β and BDNF had slightly higher expression in the cervical segment of elderly individuals. A senescent profile with elevated VEGF, MMP-2 and MMP-3 was observed across most G2 disc regions and were generally elevated from G1. In conclusion, the mere presence of any of the studied molecules inside the IVD cannot be considered pathologic. Expression of remodeling enzymes and inflammatory mediators is relatively similar across different vertebral segments and disc regions leading to a common degenerated pattern, while neurotrophins have slightly higher expression in cervical discs. These findings support the concept that disc remodeling in different segments follows a similar pathway that can be potentially mediated to avoid structural failure., Competing Interests: The authors have declared that no competing interests exist.

Vascular anomalies involving the V3 segment of the vertebral artery are common and may complicate posterior atlantoaxial instrumentation. We report a patient with a fenestrated vertebral artery that underwent successful C1-2 instrumentation and fusion. Various vertebral artery anomalies are discussed with a review of pertinent literature.

The normal aging of the extracellular matrix and collagen content of the human lumbar intervertebral disc (IVD) remains relatively unknown despite vast amounts of basic science research, partly because of the use of inadequate surrogates for a truly normal, human IVD. Our objective in this study was to describe and compare the morphology and ultrastructure of lumbar IVDs in 2 groups of young (G1-<35 years) and elderly (G2->65 years). Thirty L4-5 and L5-S1 discs per group were obtained during autopsies of presumably-asymptomatic individuals and analyzed with magnetic resonance imaging (MRI), a morphological grading scale, light microscopy, scanning electron microscopy (SEM) and immunohistochemistry (IHC) for collagen types I, II, III, IV, V, VI, IX and X. As expected, a mild to moderate degree of degeneration was present in G1 discs and significantly more advanced in G2. The extracellular matrix of G2 discs was significantly more compact with an increase of cartilaginous features such as large chondrocyte clusters. Elastic fibers were abundant in G1 specimens and their presence correlated more with age than with degeneration grade, being very rare in G2. SEM demonstrated persistence of basic structural characteristics such as denser lamellae with Sharpey-type insertions into the endplates despite advanced age or degeneration grades. Immunohistochemistry revealed type II collagen to be the most abundant type followed by collagen IV. All collagen types were detected in every disc sector except for type X collagen. Statistical analysis demonstrated a general decrease in collagen expression from G1 to G2 with an annular- and another nuclear-specific pattern. These results suggest modifications of IVD morphology do not differ between the anterior or posterior annulus but are more advanced or happen earlier in the posterior areas of the disc. This study finally describes the process of extracellular matrix modification during disc degeneration in an unselected, general population and demonstrates it is similar to the same process in the cervical spine as published previously., Competing Interests: The authors have declared that no competing interests exist.