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Objective: Smoking has been shown to negatively impact spinal health, as well as the outcomes of spinal fusion. Published reports show conflicting data regarding whether smoking negatively impacts patient outcomes following lumbar decompression. The objective of this study was to investigate whether smoking affects the outcomes of patients undergoing lumbar decompression for spinal stenosis or herniated disc., Methods: The Quality Outcomes Database was queried for patients with spinal stenosis or lumbar disc herniation who underwent one- or two-level lumbar decompression without fusion. All patients had preoperative and 12-month outcome measures and were divided into groups of nonsmokers and current smokers. Outcomes were compared between the two groups, as well as the percentage of patients reaching the minimal clinically important difference (MCID) threshold for numeric rating scale (NRS) back and leg pain scores and the Oswestry Disability Index (ODI)., Results: Of 17,271 patients, 14,233 were nonsmokers and 3038 were current smokers. Smokers had worse baseline NRS back and leg pain, ODI, and EQ-5D scores and experienced slightly less improvement in all measures following lumbar decompression (p ≤ 0.009), although changes were largely similar, and a high percentage of patients achieved the MCID thresholds for NRS back pain (78% nonsmokers vs 75% smokers), NRS leg pain (79% nonsmokers vs 73% smokers), and ODI (74% nonsmokers vs 68% smokers). Comparison of propensity-matched cohorts did not identify any difference in outcomes in smokers versus nonsmokers., Conclusions: In patients undergoing lumbar decompression for spinal stenosis or herniated disc, smokers demonstrated slightly less improvement in outcomes compared with nonsmokers, and a high proportion of both groups achieved meaningful improvement with surgery. While smoking cessation should be strongly encouraged in all patients, lumbar decompression procedures for spinal stenosis and herniated disc should not be denied to smokers.

Objective: Despite efforts toward achieving gender-based equality in clinical trial enrollment, females are frequently underrepresented and gender-specific data analysis is lacking. Identifying and addressing gender bias in medical decision-making and outcome reporting may facilitate more equitable healthcare delivery. This study aimed to determine if gender differences exist in the clinical evaluation and surgical management of patients with degenerative lumbar conditions., Methods: Consecutive adult patients undergoing spinal surgery for degenerative lumbar conditions (disc herniation [DH], spinal canal stenosis [SCS], and degenerative spondylolisthesis [DS]) were prospectively enrolled across 16 tertiary academic centers. Outcome domains included pain, disability, health-related quality of life (HRQOL), expectations of surgery, and satisfaction with surgical outcome. Covariates pertaining to the preoperative use of healthcare resources, diagnostic testing, and visits to healthcare providers were compared between genders before and after propensity score matching for 13 baseline demographic and procedural variables., Results: Data were analyzed for 5038 patients (2396 female, 2642 male) with degenerative spinal pathologies including SCS (40.2%), DS (33.2%), and DH (26.6%). Surgical treatment effect was similar for both genders. For all conditions, female patients had worse pre- and postoperative pain, disability, and HRQOL. Significant gender differences were identified for marital status, education, employment status, exercise activities, and disability claims. Female patients were more likely to use select medications, diagnostic imaging tests, and nonsurgical therapeutic interventions, and access various healthcare providers. Findings were similar following post hoc propensity score matching., Conclusions: In this multicenter, prospective, observational cohort study, male and female patients benefitted similarly from surgery for degenerative lumbar spine disease. However, female patients had worse preoperative clinical assessment scores and were more likely to use select healthcare resources.

Objective: Microsurgical decompression for patients with symptomatic lumbar spinal stenosis (LSS) has demonstrated long-term improvement concerning pain and function. Nonetheless, a considerable proportion of these patients do not experience satisfactory alleviation of symptoms. Previous studies have not found a direct influence of single sagittal parameters on patient outcomes. However, recent research indicates that a composite of parameters, presented in specific sagittal profile types (SPTs) that were defined by Roussouly and colleagues, may affect these outcomes. This study aims to investigate the impact of SPT on long-term outcomes of patients with LSS following microsurgical decompression., Methods: This study is a prospective clinical observation. Patients with symptomatic LSS, who underwent microsurgical treatment and had long-term follow-up data for at least 36 months, were included. Patients with spinal deformity, fractures, or significant instability were excluded. Outcomes were measured using the numeric rating scale for pain, 36-Item Short Form Health Survey for quality of life, walking distance, Oswestry Disability Index, Roland-Morris Disability Questionnaire, and Odom's criteria. SPT was determined in blinded fashion by using preoperative long standing radiographs., Results: The initial population of this observational study consisted of 128 patients, with long-term results available for 87 individuals, including 24 patients with SPT1, 20 with SPT2, 27 with SPT3, and 16 with SPT4. The average age was 70 years, with a slight male majority (56.3%) and a mean BMI of 27.9 kg/m2. After a median follow-up of 48 months, all groups showed significant improvement in walking distance, leg pain, and disability. Overall, 75% reported satisfaction with the surgery. However, patients with SPT1, which is characterized by low sacral slope and specific spinal curvatures, experienced significantly less improvement in back pain (p = 0.018) and related disability (p = 0.030), and lower satisfaction compared to other SPT groups (p = 0.008)., Conclusions: The sagittal spinal type is influencing the long-term outcome of patients suffering from symptomatic LSS. Patients with a combination of a flat sacral slope and a low overall lumbar lordosis with a high lordosis in the lower lumbar spine (i.e., spinal SPT1) showed worse outcome concerning back pain and had decreased satisfaction with surgery than comparable subjects from other SPT groups. Consequently, the authors recommend the assessment of sagittal spinal types in patients diagnosed with symptomatic spinal stenosis prior to decompression surgery. Inclusion of SPT in the preoperative consultation process can provide valuable insights, potentially guiding practitioners to more tailored patient counseling.

Objective: In this study, the authors aimed to determine the mid- to long-term outcomes of microendoscopic laminotomy (MEL) for lumbar spinal stenosis (LSS) with degenerative spondylolisthesis (DS) and identify preoperative predictors of poor mid- to long-term outcomes., Methods: The authors retrospectively reviewed the medical records of 274 patients who underwent spinal MEL for symptomatic LSS. The minimum postoperative follow-up duration was 5 years. Patients were classified into two groups according to DS: those with DS (the DS+ group) and those without DS (the DS- group). The patients were subjected to propensity score matching based on sex, age, BMI, surgical segments, and preoperative leg pain visual analog scale scores. Clinical outcomes were evaluated 1 year and > 5 years after surgery., Results: Surgical outcomes of MEL for LSS were not significantly different between the DS+ and DS- groups at the final follow-up (mean 7.8 years) in terms of Oswestry Disability Index (p = 0.498), satisfaction (p = 0.913), and reoperation rate (p = 0.154). In the multivariate analysis, female sex (standard β -0.260), patients with slip angle > 5° in the forward bending position (standard β -0.313), and those with dynamic progression of Meyerding grade (standard β -0.325) were at a high risk of poor long-term outcomes., Conclusions: MEL may have good long-term results in patients with DS without dynamic instability. Women with dynamic instability may require additional fusion surgery in approximately 25% of cases for a period of ≥ 5 years.

Objective: This study aimed to quantify pre- and postoperative paraspinal muscular variation following posterior lumbar interbody fusion (PLIF) in patients with degenerative lumbar spinal stenosis (DLSS) and measure the association of this variation with adjacent-segment degeneration (ASD)., Methods: Data from 149 patients who underwent L4-S1 PLIF for DLSS were collected. Patients were divided into radiologically confirmed ASD and control groups according to follow-up radiological findings. MRI was performed before surgery and at the last follow-up. Muscular parameters including the relative cross-sectional area (rCSA), relative functional cross-sectional area (rFCSA), relative total cross-sectional area (rTCSA), and fatty infiltration (FI) of the multifidus (MF), erector spinae (ES), and psoas major (PM) muscles were measured on preoperative and follow-up L2-S1 MR images. Logistic regression was used to investigate risk factors for ASD., Results: The rate of radiological ASD was 42.3% at the final follow-up (mean 25.71 ± 8.35 months). At surgical levels, the rFCSA and rTCSA of the MF and ES muscles decreased. The FI of the MF from L2-3 to L5-S1 and ES muscles at L5-S1 significantly increased after surgery, while the rFCSA and rTCSA of the PM muscle increased and its FI decreased. At adjacent levels, the rFCSA and rTCSA of the MF muscle and rTCSA of the ES muscle decreased and the FI of the MF muscle increased postoperatively (p < 0.05), but the rFCSA and rTCSA of the PM muscle increased and its FI decreased (p < 0.05). The FIs of the MF, ES, and PM muscles at adjacent levels significantly differed between the ASD and control groups. Logistic regression analysis indicated that higher BMI (p = 0.002) and FI of the PM muscle at adjacent levels (p = 0.025) were significant risk factors for ASD., Conclusions: The functional area decreased in the MF and ES muscles and increased in the PM muscle after L4-S1 PLIF. A compensatory postoperative decrease in FI of the PM muscle at the adjacent level was a protective factor for ASD in DLSS patients after PLIF.

Objective: Lumbar spine decompression surgery, in the form of laminectomy or discectomy, is known to be effective in improving symptoms of radiculopathy and neurogenic claudication. However, it is less clear how it impacts coexisting low-back pain (LBP). The aim of this study was to quantify the change in LBP after lumbar decompression., Methods: This study analyzed data from the British Spine Registry on patients who underwent lumbar decompression surgery. LBP severity was assessed using the visual analog scale (VAS), and the primary outcome was the change in VAS score at 1 year, with secondary outcomes measuring the change in score at 6 weeks, 6 months, and 2 years. The minimal clinically important difference (MCID) was defined as a 30% reduction in pain., Results: Of the 25,349 patients included in the study, 92.2% reported significant back pain at baseline. Of the entire cohort, 12,951 (55.4%) patients had follow-up data for 6 weeks, 9066 (38.8%) for 6 months, 7926 (33.9%) for 1 year, and 5517 (23.6%) for 2 years; 17,304 (68.3%) patients had follow-up data for at least one time point. Sixty-two percent of patients attained the MCID (VAS score ≥ 30%) in back pain reduction, with 51% reporting a substantial improvement (VAS score ≥ 50%). This improvement was observed by 6 weeks postoperation and was mostly maintained at 2 years. Patients with back pain predominance were more likely to attain the MCID compared with those with leg pain predominance (63.6% vs 60.1%; OR 1.16, 95% CI 1.02-1.34; p = 0.0291). Severity of baseline back pain did not reduce the proportion attaining the MCID., Conclusions: Regardless of pain presentation, LBP improves in approximately 62% of patients who undergo lumbar decompressive surgery, with 51% experiencing substantial improvement. Patients undergoing lumbar decompression can be advised on the chance of a meaningful improvement in back pain postsurgery.

Objective: The objective of this study was to assess the outcomes of patients with predominant back pain (pBP) undergoing minimally invasive decompression surgery compared with patients with nonpredominant back pain (npBP)., Methods: This was a retrospective cohort study. Patients were divided into two groups based on the presenting complaint: 1) pBP, defined as visual analog scale (VAS) back pain score > VAS leg pain score; and 2) npBP. Changes in patient-reported outcome measures (PROMs) were compared at the early (< 6 months) and late (≥ 6 months) postoperative time points. Outcomes measures were: 1) PROMs (Oswestry Disability Index [ODI], VAS back and leg pain scores, 12-Item Short-Form Health Survey Physical Component Score [SF-12 PCS], and Patient-Reported Outcomes Measurement Information System Physical Function [PROMIS PF]), and 2) minimal clinically important difference (MCID) achievement rate and time. For the late MCID achievement point, a second analysis was conducted restricting VAS back and leg pain scores only to patients with preoperative scores ≥ 5., Results: Three hundred ninety patients were included (126 with pBP and 264 with npBP). There were no differences in patient demographics and operated levels. There were no differences in preoperative ODI, SF-12 PCS, and PROMIS PF scores. The pBP cohort had a significantly greater preoperative VAS back pain score than the npBP cohort, whereas the npBP cohort had a significantly greater preoperative VAS leg pain score than the pBP cohort. There were no differences in the absolute values or changes in ODI, VAS back pain, SF-12 PCS, and PROMIS PF scores at any time point. There was a significant difference in the early VAS leg pain scores (greater in npBP) that disappeared by the late postoperative time point. There was no difference in the MCID achievement rate in the ODI, SF-12 PCS, or PROMIS PF scores. By the late postoperative time point, 51.2% and 55.3% achieved an MCID on the ODI, 58.1% and 62.7% on the SF-12 PCS, 60% and 67.6% on the PROMIS PF, 81.1% and 73.2% on VAS back pain scores for those with preoperative scores ≥ 5, and 72% and 83.6% on VAS leg pain scores for those with preoperative scores ≥ 5 for the pBP and npBP cohorts, respectively. Additionally, there were no differences in time to MCID achievement for any PROMs., Conclusions: The pBP and npBP cohorts showed similar improvement in PROMs and MCID achievement rates. This result shows that minimally invasive laminectomy is equally effective for patients presenting with pBP or npBP.

Objective: Clear diagnostic delineation is necessary for the development of a strong evidence base in lumbar spinal surgery. Experience with existing national databases suggests that International Classification of Diseases, Tenth Edition (ICD-10) coding is insufficient to support that need. The purpose of this study was to assess agreement between surgeon-specified diagnostic indication and hospital-reported ICD-10 codes for lumbar spine surgery., Methods: Data collection for the American Spine Registry (ASR) includes an option to denote the surgeon's specific diagnostic indication for each procedure. For cases treated between January 2020 and March 2022, surgeon-delineated diagnosis was compared with the ICD-10 diagnosis generated by standard ASR electronic medical record data extraction. For decompression-only cases, the primary analysis focused on the etiology of neural compression as determined by the surgeon versus that determined on the basis of the related ICD-10 codes extracted from the ASR database. For lumbar fusion cases, the primary analysis compared structural pathology, which may have required fusion, as determined by the surgeon versus that determined on the basis of the extracted ICD-10 codes. This allowed for identification of agreement between surgeon delineation and extracted ICD-10 codes., Results: In 5926 decompression-only cases, agreement between the surgeon and ASR ICD-10 codes was 89% for spinal stenosis and 78% for lumbar disc herniation and/or radiculopathy. Both the surgeon and database indicated no structural pathology (i.e., none) suggesting the need for fusion in 88% of cases. In 5663 lumbar fusion cases, agreement was 76% for spondylolisthesis but poor for other diagnostic indications., Conclusions: Agreement between surgeon-specified diagnostic indication and hospital-reported ICD-10 codes was best for patients who underwent decompression only. In the fusion cases, agreement with ICD-10 codes was best in the spondylolisthesis group (76%). In cases other than spondylolisthesis, agreement was poor due to multiple diagnoses or lack of an ICD-10 code that reflected the pathology. This study suggested that standard ICD-10 codes may be inadequate to clearly define the indications for decompression or fusion in patients with lumbar degenerative disease.

Objective: Lumbar stenosis treatment has evolved with the introduction of minimally invasive surgery (MIS) techniques. Endoscopic methods take the concepts applied to MIS a step further, with multiple studies showing that endoscopic techniques have outcomes that are similar to those of more traditional approaches. The aim of this study was to perform an updated meta-analysis and systematic review of studies comparing the outcomes between endoscopic (uni- and biportal) and microscopic techniques for the treatment of lumbar stenosis., Methods: Following PRISMA guidelines, a systematic search was performed using the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Ovid Embase, and PubMed databases from their dates of inception to December 14, 2020. All identified articles were then systematically screened against the following inclusion criteria: 1) studies comparing endoscopic (either uniportal or biportal) with minimally invasive approaches, 2) patient age ≥ 18 years, and 3) diagnosis of lumbar spinal stenosis. Bias was assessed using quality assessment criteria and funnel plots. Meta-analysis using a random-effects model was used to synthesize the metadata., Results: From a total of 470 studies, 14 underwent full-text assessment. Of these 14 studies, 13 comparative studies were included for quantitative analysis, totaling 1406 procedures satisfying all criteria for selection. Regarding postoperative back pain, 9 studies showed that endoscopic methods resulted in significantly lower pain scores compared with MIS (mean difference [MD] -1.0, 95% CI -1.6 to -0.4, p < 0.01). The length of stay data were reported by 7 studies, with endoscopic methods associated with a significantly shorter length of stay versus the MIS technique (MD -2.1 days, 95% CI -2.7 to -1.4, p < 0.01). There was no significant difference with respect to leg visual analog scale scores, Oswestry Disability Index scores, blood loss, surgical time, and complications, and there were not any significant quality or bias concerns., Conclusions: Both endoscopic and MIS techniques are safe and effective methods for treating patients with symptomatic lumbar stenosis. Patients who undergo endoscopic surgery seem to report less postoperative low-back pain and significantly reduced hospital stay with a trend toward less perioperative blood loss. Future large prospective randomized trials are needed to confirm the findings in this study.

Objective: The authors sought to evaluate the relationship between the difference in lumbar lordosis (DiLL) in the preoperative supine and standing positions and spinal sagittal alignment in patients with lumbar spinal stenosis (LSS) and to determine whether this difference affects the clinical outcome of laminectomy., Methods: Sixty patients who underwent single-level unilateral laminectomy for bilateral decompression of LSS were evaluated. Spinopelvic parameters in the supine and standing positions were measured preoperatively and at 3 months and 2 years postoperatively. DiLL between the supine and standing positions was determined as follows: DiLL = supine LL - standing LL. On the basis of this determination patients were then categorized into DiLL(+) and DiLL(-) groups. The relationship between DiLL and preoperative spinopelvic parameters was evaluated using Pearson's correlation coefficient. In addition, clinical outcomes such as visual analog scale (VAS) and Oswestry Disability Index (ODI) scores between the two groups were measured, and their relationship to DiLL was evaluated using two-group comparison and multivariate analysis., Results: There were 31 patients in the DiLL(+) group and 29 in the DiLL(-) group. DiLL was not associated with supine LL but was strongly correlated with standing LL and pelvic incidence (PI) - LL (PI - LL). In the preoperative spinopelvic alignment, LL and SS in the standing position were significantly smaller in the DiLL(+) group than in the DiLL(-) group, and PI - LL was significantly higher in the DiLL(+) group than in the DiLL(-) group. There was no difference in the clinical outcomes 3 months postoperatively, but low-back pain, especially in the sitting position, was significantly higher in the DiLL(+) group 2 years postoperatively. DiLL was associated with low-back pain in the sitting position, which was likely to persist in the DiLL(+) group postoperatively., Conclusions: We evaluated the relationship between DiLL and spinal sagittal alignment and the influence of DiLL on postoperative outcomes in patients with LSS. DiLL was strongly correlated with PI - LL, and in the DiLL(+) group, postoperative low-back pain relapsed. DiLL can be useful as a new spinal alignment evaluation method that supports the conventional spinal sagittal alignment evaluation.

Objective: This report describes a minimally invasive lumbar foraminotomy technique that can be applied in patients who underwent complex spine decompression procedures or in patients with severe foraminal stenosis., Methods: Awake, endoscopic decompression surgery was performed in 538 patients over a 5-year period between 2014 and 2019. Transforaminal endoscopic foraminal decompression surgery using a high-speed endoscopic drill was performed in 34 patients who had previously undergone fusions at the treated level., Results: At 2-year follow-up, the mean (± SD) preoperative visual analog scale score for leg pain and the Oswestry Disability Index improved from 7.1 (± 1.5) and 40.1% (± 12.1%) to 2.1 (± 1.9) and 13.6% (± 11.1%)., Conclusions: A minimally invasive, awake procedure is presented for the treatment of severe lumbar foraminal stenosis in patients with lumbar radiculopathy after lumbar fusion.

Objective: Although several reports have described adjacent-segment disease (ASD) after posterior lumbar interbody fusion (PLIF), there have been only a few reports focusing on early-onset ASD occurring within 3 years after primary PLIF. The purpose of this study was to investigate the prevalence and postoperative pathologies of early-onset ASD and its relation with radiological parameters such as segmental lordosis (SL)., Methods: The authors reviewed a total of 256 patients who underwent single-segment PLIF at L4-5 for degenerative lumbar spondylolisthesis (DLS) and were followed up for at least 5 years. The definition of ASD was a symptomatic condition requiring an additional operation at the adjacent fusion segment in patients who had undergone PLIF. ASD occurring within 3 years after primary PLIF was categorized as early-onset ASD. As a control group, 54 age- and sex-matched patients who had not suffered from ASD for more than 10 years were selected from this series., Results: There were 42 patients with ASD at the final follow-up. ASD prevalence rates at 3, 5, and 10 years postoperatively and at the final follow-up were 5.0%, 8.2%, 14.1%, and 16.4%, respectively. With respect to ASD pathologies, lumbar disc herniation (LDH) was significantly more common in early-onset ASD, while lumbar spinal stenosis and DLS occurred more frequently in late-onset ASD. Significant differences were detected in the overall postoperative range of motion (ROM) and in the changes in ROM (ΔROM) at L3-4 (the cranial adjacent fusion segment) and changes in SL (ΔSL) at L4-5 (the fused segment), while there were no significant differences in other pre- and postoperative parameters. In stepwise logistic regression analysis, ΔSL was identified as an independent variable (p = 0.008) that demonstrated significant differences, especially in early-onset ASD (control 1.1° vs overall ASD -2.4°, p = 0.002; control 1.1° vs early-onset ASD -6.6°, p = 0.00004)., Conclusions: The study results indicated that LDH was significantly more common as a pathology in early-onset ASD and that ΔSL was a major risk factor for ASD, especially early-onset ASD.

Objective: Lumbar spinal stenosis (LSS) is a common and debilitating condition that is increasing in prevalence in the world population. Surgical decompression is often standard treatment when conservative measures have failed. Interspinous distractor devices (IDDs) have been proposed as a safe alternative; however, the associated cost and early reports of high failure rates have brought their use into question. The primary objective of this study was to determine the cost-effectiveness and long-term quality-of-life (QOL) outcomes after treatment of LSS with the X-Stop IDD compared with surgical decompression by laminectomy., Methods: A multicenter, open-label randomized controlled trial of 47 patients with LSS was conducted; 21 patients underwent insertion of the X-Stop device and 26 underwent laminectomy. The primary outcomes were monetary cost and QOL measured using the EQ-5D questionnaire administered at 6-, 12-, and 24-month time points., Results: The mean monetary cost for the laminectomy group was £2712 ($3316 [USD]), and the mean cost for the X-Stop group was £5148 ($6295): £1799 ($2199) procedural cost plus £3349 mean device cost (£2605 additional cost per device). Using an intention-to-treat analysis, the authors found that the mean quality-adjusted life-year (QALY) gain for the laminectomy group was 0.92 and that for the X-Stop group was 0.81. The incremental cost-effectiveness ratio was -£22,145 (-$27,078). The revision rate for the X-Stop group was 19%. Five patients crossed over to the laminectomy arm after being in the X-Stop group., Conclusions: Laminectomy was more cost-effective than the X-Stop for the treatment of LSS, primarily due to device cost. The X-Stop device led to an improvement in QOL, but it was less than that in the laminectomy group. The use of the X-Stop IDD should be reserved for cases in which a less-invasive procedure is required. There is no justification for its regular use as an alternative to decompressive surgery. Clinical trial registration no.: ISRCTN88702314 (www.isrctn.com).

Objective: Whereas the benefits of indirect decompression after lateral lumbar interbody fusion are well known, the effects of anterior lumbar interbody fusion (ALIF) have not yet been verified. The purpose of this study was to evaluate the clinical and radiological effects of indirect decompression after ALIF for central spinal canal stenosis. In this report, along with the many advantages of the anterior approach, the authors share cases with good outcomes that they have encountered., Methods: The authors performed a retrospective analysis of 64 consecutive patients who underwent ALIF for central spinal canal stenosis with instability and mixed foraminal stenosis between January 2015 and December 2018 at their hospital. Clinical assessments were performed using the visual analog scale score, the Oswestry Disability Index, and the modified Macnab criteria. The radiographic parameters were determined from pre- and postoperative cross-sectional MRI scans of the spinal canal and were compared to evaluate neural decompression after ALIF. The average follow-up period was 23.3 ± 1.3 months., Results: All clinical parameters, including the visual analog scale score, Oswestry Disability Index, and modified Macnab criteria, improved significantly. The mean operative duration was 254.8 ± 60.8 minutes, and the intraoperative bleeding volume was 179.8 ± 119.3 ml. In the radiological evaluation, radiological parameters of the cross-sections of the spinal canal showed substantial development. The spinal canal size improved by an average of 43.3% (p < 0.001) after surgery. No major complications occurred; however, aspiration guided by ultrasonography was performed in 2 patients because of a pseudocyst and fluid collection., Conclusions: ALIF can serve as a suitable alternative to extensive posterior approaches. The authors suggest that ALIF can be used for decompression in central spinal canal stenosis as well as restoration of the foraminal dimensions, thus allowing decompression of the nerve roots.

Objective: Facet cysts may represent a sign of intrinsic facet disease and instability, increasing the importance of less-invasive approaches that limit tissue dissection and improve visualization. The authors developed an intraoperative cyst-dyeing technique, involving the injection of indigo carmine from the facet joint into the cyst, as an adjunct during decompression. This study aimed to evaluate the clinical outcomes and perioperative complication rates of microendoscopic spinal decompression for lumbar spinal stenosis (LSS) and lumbar foraminal stenosis (LFS), caused by facet cysts and to elucidate the efficacy of the cyst-dyeing method in microendoscopic surgery for facet cysts., Methods: Forty-eight consecutive patients who underwent surgical treatment with microendoscopic decompression for symptomatic LSS or LFS caused by facet cysts from 2011 to 2018 were reviewed. These patients were divided into two groups: a group that did not receive dye (N), with the patients undergoing surgery from April 2011 to May 2015; and a group that received dye (D), with patients undergoing surgery from June 2015 to March 2018. The authors evaluated the operative time, blood loss, perioperative complications, visual analog scale scores for low-back and leg pain, and Japanese Orthopaedic Association scores. Surgical outcome was evaluated 2 years postoperatively and was compared between groups D and N., Results: The clinical outcomes were generally excellent or good. Group N consisted of 36 patients and group D of 12 patients. Comparing the clinical results, it was found that the cyst-dyeing method reduced the perioperative complication rate, including reduction in dural tears to 0%, and shortened the average operative time by approximately 40 minutes., Conclusions: In this study, the authors demonstrated that the clinical outcomes of microendoscopic spinal decompression in patients with LSS or LFS caused by facet-joint cysts are generally favorable. Additionally, the adjunctive cyst-dyeing method effectively delineated the cystic and dural boundaries, facilitating safer and more effective cyst separation and neural decompression. Microendoscopic surgery combined with this novel facet cyst-dyeing method is a safe and effective minimally invasive technique for facet-joint cysts.

Objective: Age is commonly thought to be a risk factor in defining lumbar spinal stenosis (LSS) degenerative or developmental subtypes. This article is a follow-up to a previous article ("Redefining Lumbar Spinal Stenosis as a Developmental Syndrome: An MRI-Based Multivariate Analysis of Findings in 709 Patients Throughout the 16- to 82-Year Age Spectrum") that describes the radiological differences between developmental and degenerative types of LSS. MRI-based analysis of "degeneration" variables and spinal canal morphometric characteristics of LSS segments have been thought to correlate with age at presentation., Methods: The authors performed a re-analysis of data from their previously reported prospective MRI-based study, stratifying data from the 709 cases into 3 age categories of equal size (instead of the original < 60 vs ≥ 60 years). Relative spinal canal dimensions, as well as radiological degenerative variables from L1 to S1, were analyzed across age groups in a multivariate mode. The total degenerative scale score (TDSS) for each lumbar segment from L1 to S1 was calculated for each patient. The relationships between age and qualitative stenosis grades, TDSS, disc degeneration, and facet degeneration were analyzed using Pearson's product-moment correlation and multiple regression., Results: Multivariate analysis of TDSS and spinal canal dimensions revealed highly significant differences across the 3 age groups at L2-3 and L3-4 and a weaker, but still significant, association with changes at L5-S1. Age helped to explain only 9.6% and 12.2% of the variance in TDSS at L1-2 and L2-3, respectively, with a moderate positive correlation, and 7.8%, 1.2%, and 1.9% of the variance in TDSS at L3-4, L4-5, and L5-S1, respectively, with weak positive correlation. Age explained 24%, 26%, and 18.4% of the variance in lumbar intervertebral disc (LID) degeneration at L1-2, L2-3, and L3-4, respectively, while it explained only 6.2% and 7.2% of the variance of LID degeneration at L4-5 and L5-S1, respectively. Age explained only 2.5%, 4.0%, 1.2%, 0.8%, and 0.8% of the variance in facet degeneration at L1-2, L2-3, L3-4, L4-5, and L5-S1, respectively., Conclusions: Age at presentation correlated weakly with degeneration variables and spinal canal morphometries in LSS segments. Age correlated with upper lumbar segment (L1-4) degeneration more than with lower segment (L4-S1) degeneration. The actual chronological age of the patients did not significantly correlate with the extent of degenerative pathology of the lumbar stenosis segments. These study results lend support for a developmental contribution to LSS.

Objectives: The objective of this study was to evaluate the incidence and risk factors for 90-day readmission and reoperation after elective surgery for lumbar spinal stenosis (LSS)., Methods: The authors performed a retrospective consecutive cohort analysis of patients undergoing posterior lumbar decompression with or without fusion for LSS with claudication from January 2014 through December 2015., Results: Data were collected on 1592 consecutive patients. The mean age at surgery was 67.4 ± 10.1 years and 45% of patients were female. The 90-day reoperation rate was 4.7%, and 69.3% of the reoperations occurred within the first 30 days. The 90-day readmission rate was 7.2%. Multivariable analysis showed that postoperative development of a surgical site infection (SSI; odds ratio [OR] 14.09, 95% confidence interval [CI] 7.86–25.18), acute kidney injury (AKI; OR 6.76, 95% CI 2.39–19.57), and urinary tract infection (UTI; OR 3.96, 95% CI 2.43–6.37), as well as a history of congestive heart failure (CHF; OR 3.03, 95% CI 1.69–5.28), were significant risk factors for readmission within 90 days. Male sex (OR 0.60, 95% CI 0.38–0.92) was associated with decreased odds for readmission. With regards to reoperation, development of SSI (OR 25.06, 95% CI 13.54–46.51), sepsis (OR 7.63, 95% CI 1.52–40.59), UTI (OR 2.54, 95% CI 1.31–4.76), and increased length of stay (LOS; OR 1.25, 95% CI 1.17–1.33) were found to be significant risk factors. A subsequent analysis found that morbid obesity (OR 6.99), history of coronary artery disease (OR 2.263), increased duration of surgery (OR 1.004), and LOS (OR 1.07) were significant risk factors for developing an SSI., Conclusions: Overall, this study found rates of 4.7% and 7.2% for reoperation and readmission, respectively, within 90 days: 30.7% of the reoperations and 44.7% of the readmissions occurred beyond the first 30 days. A diagnosis of SSI, AKI, UTI, and history of CHF were significant factors for readmission, while male sex was associated with decreased odds for readmission. A diagnosis of SSI, sepsis, UTI, and increased LOS were found to be significant predictors for reoperation. Understanding 90-day complication rates is imperative because there has been increased discussion and healthcare policy extending the global postoperative window to 90 days. Current literature supports a readmission rate of 3%–9% after spine surgery. However, this literature either is limited to a 30-day window or does not stratify between different types of spine surgeries., Abbreviations: AKI = acute kidney injury; BPH = benign prostate hyperplasia; CAD = coronary artery disease; CHF = congestive heart failure; CI = confidence interval; CMS = Centers for Medicare and Medicaid Services; COPD = chronic obstructive pulmonary disease; DM = diabetes mellitus; EBL = estimated blood loss; LOS = length of stay; LSS = lumbar spinal stenosis; OR = odds ratio; POUR = postoperative urinary retention; SSI = surgical site infection; UTI = urinary tract infection., Competing Interests: Dr. Mroz reports being a consultant for Stryker. Dr. Steinmetz reports being a consultant for Intellirod and Globus; receiving support of non–study-related clinical or research effort from Globus; and receiving honoraria and royalties from Stryker, Globus, Zimmer Biomet, and Elsevier.

In BriefThe time course required for the patient-reported outcomes of pain, physical function, and mental health to reach a recovery plateau after elective lumbar spine surgery was assessed utilizing a prospectively maintained multicenter registry. The work is important as it demonstrates that specific health dimensions follow different recovery plateaus and it provides evidence that a 2-year postoperative follow-up is not required to accurately assess the treatment effect of established surgeries for lumbar spinal pathologies.

The authors report on the first surgical treatment for traumatic interspinous ligament calcification, with significant radiographic and symptomatic improvements at long-term follow-up. Heterotopic ossification occurs following traumatic injury but does not typically affect the interspinous ligaments. While these ligaments can calcify with age, this is rarely seen in patients younger than 50 years of age. The authors present the unusual case of a 31-year-old man who suffered traumatic fractures of thoracic and lumbar spinous processes. He developed progressive low-back pain that failed to respond to conservative treatments. At presentation, he was neurologically intact. CT scanning demonstrated partial calcification of the interspinous ligaments at L2-3, L3-4, and L4-5 with significant hypertrophy of the spinous processes at those levels. He did not have significant disc pathology, and his symptoms were attributed to the limited range of motion caused by the enlarged spinous processes. Partial resection of the spinous processes and calcified interspinous ligaments was performed to remove the heterotopic bone. The patient was seen in follow-up at 5 months postoperatively for imaging, and he was interviewed at 1 and 2 years postoperatively. He is doing well with significant pain relief and an improved range of motion. His Oswestry Disability Index improved from 25 preoperatively to 18 at 2 years postoperatively.

OBJECTIVEThe pedicle screw-based Dynesys dynamic stabilization (DDS) has reportedly become a surgical option for lumbar spondylosis and spondylolisthesis. However, it is still unclear whether the dynamic construct remains mobile or eventually fuses. The aim of this study was to investigate the incidence of unintended facet arthrodesis after DDS and its association with spondylolisthesis.METHODSThis retrospective study was designed to review 105 consecutive patients with 1- or 2-level lumbar spondylosis who were treated with DDS surgery. The patients were then divided into 2 groups according to preexisting spondylolisthesis or not. All patients underwent laminectomies, foraminotomies, and DDS. The clinical outcomes were measured using visual analog scale (VAS) scores for back and leg pain, Japanese Orthopaedic Association (JOA) scores, and Oswestry Disability Index (ODI) scores. All medical records, including pre- and postoperative radiographs, CT scans, and MR images, were also reviewed and compared.RESULTSA total of 96 patients who completed the postoperative follow-up for more than 30 months were analyzed. The mean age was 64.1 ± 12.9 years, and the mean follow-up duration was 46.3 ± 12.0 months. There were 45 patients in the spondylolisthesis group and 51 patients in the nonspondylolisthesis group. The overall prevalence rate of unintended facet fusion was 52.1% in the series of DDS. Patients with spondylolisthesis were older (67.8 vs 60.8 years, p = 0.007) and had a higher incidence rate of facet arthrodesis (75.6% vs 31.4%, p < 0.001) than patients without spondylolisthesis. Patients who had spondylolisthesis or were older than 65 years were more likely to have facet arthrodesis (OR 6.76 and 4.82, respectively). There were no significant differences in clinical outcomes, including VAS back and leg pain, ODI, and JOA scores between the 2 groups. Furthermore, regardless of whether or not unintended facet arthrodesis occurred, all patients experienced significant improvement (all p < 0.05) in the clinical evaluations.CONCLUSIONSDuring the mean follow-up of almost 4 years, the prevalence of unintended facet arthrodesis was 52.1% in patients who underwent DDS. Although the clinical outcomes were not affected, elderly patients with spondylolisthesis might have a greater chance of facet fusion. This could be a cause of the limited range of motion at the index levels long after DDS.

Ossification of the ligamentum flavum (OLF) is a well-recognized but rare cause of thoracic myelopathy. Its subtle and variable clinical presentation often makes the diagnosis challenging. The treatment of symptomatic OLF requires surgical intervention, with the most common surgical procedure being a posterior decompression with or without instrumentation. Recurrence of ossification and stenosis after surgery is rare and usually occurs at the same intervertebral level. Multiple recurrences of ossification and stenosis are exceptionally rare. The authors report the case of OLF in a 60-year-old man who experienced recurrence of ossification and stenosis twice after posterior decompression surgeries alone. The patient was ultimately treated with revision decompression and instrumented fusion. The authors also present a pertinent review of the literature.

OBJECTIVEThis study aimed to investigate the characteristics of cervical degeneration in Japanese professional wrestlers and its relationship with the risk of cervical spine injury (CSI).METHODSSince 2012, 27 Japanese male wrestlers belonging to a professional wrestling association have undergone periodical medical examinations of the cervical spine. If neurological symptoms were observed in the wrestlers, the resident trainers urged them to undergo a brief examination at the authors' institutions. In addition to this prospective research study, the mechanisms of the CSIs that occurred in 5 wrestlers, including 2 with CSI before 2012 and 3 who were independent from the professional wrestling association, were retrospectively investigated by reviewing the circumstances of the injury and the wrestlers' imaging studies.RESULTSThe mean age of the wrestlers was 36.9 years (range 23-56 years) at the initial examination. An anterior giant ossifying lesion (AGOL) was observed in the anterior aspect of the cervical spine of 11 wrestlers (41%). The AGOLs tended to grow and spread to multiple spinal levels as the wrestlers aged. Of the 12 wrestlers with osteogenic lesions, 10 older than 40 years of age (83%) had an AGOL, which is frequently accompanied by osseous spinal canal stenosis. Two wrestlers presented with spinal cord compression with intramedullary intensity change on MRI. However, during the follow-up period, no spinal cord injury (SCI) occurred in the wrestlers, although thoracolumbar injury occurred in 2 wrestlers during a match. In examining the 5 wrestlers with CSI, the injury occurred at the spinal levels without an AGOL. The most frequent pathology of CSI (60%) was SCI at the spinal level adjacent to the multilevel AGOL.CONCLUSIONSAGOL is a peculiar cervical degeneration of Japanese professional wrestlers, especially in aged wrestlers. The AGOL appears to be a biological reaction to reinforce the anterior aspect of the cervical spine of professional wrestlers, who routinely defend themselves in a flexed neck posture against their opponent. The present results suggest that the risk of CSI is not increased by spinal canal stenosis accompanied by AGOL. Further studies are needed to investigate the relationship between the wrestlers' cervical degeneration and the risk of CSI in more detail.

OBJECTIVEVarious minimally invasive techniques have been described for the decompression of lumbar spinal stenosis (LSS). However, few reports have described the results of endoscopic posterior decompression (EPD) with laminectomy performed under local anesthesia. This study aimed to evaluate the clinical and radiological outcomes of EPD performed under local anesthesia in patients with LSS and to compare the procedural outcomes in patients with and without preoperative spondylolisthesis.METHODSFifty patients (28 female and 22 male) who underwent EPD under local anesthesia were included in this study. Patients were assessed before surgery and were followed up with regular outpatient visits (at 1, 3, 6, 12, and 24 months postoperatively). Clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and the 36-Item Short Form Survey (SF-36) outcome questionnaire. Radiological outcomes were assessed by measuring lumbar lordosis, disc-wedging angle, percentage of vertebral slippage, and disc height index on plain standing radiographs.RESULTSThe VAS, ODI, and SF-36 scores were significantly improved at 1 month after surgery compared to the baseline mean values, and the improved scores were maintained over the 2-year follow-up period. Radiological progression was found in 2 patients during the follow-up period. Patients with and without preoperative spondylolisthesis had no significant differences in their clinical and radiological outcomes.CONCLUSIONSEPD performed under local anesthesia is effective for LSS treatment. Similar favorable outcomes can be obtained in patients with and without preoperative spondylolisthesis using this approach.

OBJECTIVE: Insurance disparities can have relevant effects on outcomes after elective lumbar spinal surgery. The aim of this study was to evaluate the association between private/public payer status and patient-reported outcomes in adult patients who underwent decompression surgery for lumbar spinal stenosis. METHODS: A sample of 100 patients who underwent surgery for lumbar spinal stenosis from 2012 to 2014 was evaluated as part of the prospectively collected Quality Outcomes Database at a single institution. Outcome measures were evaluated at 3 months and 12 months, analyzed in regard to payer status (private insurance vs Medicare/Veterans Affairs insurance), and adjusted for potential confounders. RESULTS: At baseline, patients had similar visual analog scale back and leg pain, Oswestry Disability Index, and EQ-5D scores. At 3 months postintervention, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.11, p < 0.001) and more leg pain (mean difference 1.26, p = 0.05). At 12 months, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.14, p < 0.001). There were no significant differences at 3 months or 12 months between groups for back pain (p = 0.14 and 0.43) or disability (p = 0.19 and 0.15). Across time points, patients in both groups showed improvement at 3 months and 12 months in all 4 functional outcomes compared with baseline (p < 0.001). CONCLUSIONS: Both private and public insurance patients had significant improvement after elective lumbar spinal surgery. Patients with public insurance had slightly less improvement in quality of life after surgery than those with private insurance but still benefited greatly from surgical intervention, particularly with respect to functional status.

OBJECTIVEIt is important to identify differences in the treatment of common diseases over time and across geographic regions. Several studies have reported increased use of arthrodesis to treat lumbar spinal stenosis (LSS). The purpose of this study was to investigate geographic variations in the treatment of LSS by US region.METHODSThe authors reviewed inpatient and outpatient medical claims from 2010 to 2014 using the MarketScan Commercial Claims and Encounters database (Truven Health Analytics), which includes data on commercially insured members younger than 65 years. ICD-9 code 724.02 was used to identify patients aged ≥ 40 and < 65 years who underwent surgery for "spinal stenosis of the lumbar region" and for whom LSS was the only principal diagnosis. The primary outcome was the performance of spinal arthrodesis as part of the procedure. Geographic regions were based on patient residence and defined according to the US Census Bureau as the Northeast, Midwest, South, and West.RESULTSRates of arthrodesis, as opposed to decompression alone, varied significantly by region, from 48% in the South, to 42% in the Midwest, 36% in the Northeast, and 31% in the West. After controlling for patient age, sex, and Charlson Comorbidity Index values, the differences remained significant. Compared with patients in the Northeast, those in the South (OR 1.6, 95% CI 1.50-1.75) and Midwest (OR 1.3, 95% CI 1.18-1.41) were significantly more likely to undergo spinal arthrodesis. On multivariate analysis, patients in the West were significantly less likely to have a prolonged hospital stay (> 3 days) than those in the Northeast (OR 0.84, 95% CI 0.75-0.94). Compared with the rate in the Northeast, the rates of discharge to a skilled nursing facility were lower in the South (OR 0.41, 95% CI 0.31-0.55) and West (OR 0.72, 95% CI 0.53-0.98). The 30-day readmission rate was significantly lower in the West (OR 0.81, 95% CI 0.65-0.98) than in the Northeast and similar between the other regions. Mean payments were significantly higher in the Midwest (mean difference $5503, 95% CI $4279-$6762), South (mean difference $6187, 95% CI $5041-$7332), and West (mean difference $7732, 95% CI $6384-$9080) than in the Northeast.CONCLUSIONSThe use of spinal arthrodesis, as well as surgical outcomes and payments for the treatment of LSS, varies significantly by US region. This highlights the importance of developing national recommendations for the treatment of LSS.

OBJECTIVEThe goal of this study was to analyze the effect of patient education level on functional outcomes following decompression surgery for symptomatic lumbar spinal stenosis.METHODSPatients with surgically decompressed symptomatic lumbar stenosis were collected in a prospective observational registry at a single institution between 2012 and 2014. Patient education level was compared to surgical outcomes to elucidate any relationships. Outcomes were defined using the Oswestry Disability Index score, back and leg pain visual analog scale (VAS) score, and the EuroQol-5 Dimensions questionnaire score.RESULTSOf 101 patients with symptomatic lumbar spinal stenosis, 27 had no college education and 74 had a college education (i.e., 2-year, 4-year, or postgraduate degree). Preoperatively, patients with no college education had statistically significantly greater back and leg pain VAS scores when compared to patients with a college education. However, there was no statistically significant difference in quality of life or disability between those with no college education and those with a college education. Postoperatively, patients in both cohorts improved in all 4 patient-reported outcomes at 3 and 12 months after treatment for symptomatic lumbar spinal stenosis.CONCLUSIONSDespite their education level, both cohorts showed improvement in their functional outcomes at 3 and 12 months after decompression surgery for symptomatic lumbar spinal stenosis.

Objective: This study defines the association of preoperative physical activity level with functional outcomes at 3 and 12 months following surgical decompression for lumbar spinal stenosis., Methods: Data were collected as a prospective observational registry at a single institution from 2012 through 2015, and then analyzed with a retrospective cohort design. Patients who were able to participate in activities outside the home preoperatively were compared to patients who did not participate in such activities, with respect to 3-month and 12-month functional outcomes postintervention, adjusted for relevant confounders., Results: Ninety-nine patients were included. At baseline, sedentary/inactive patients (n = 55) reported greater back pain, lower quality of life, and higher disability than similarly treated patients who were active preoperatively. Both cohorts experienced significant improvement from baseline in back pain, leg pain, disability, and quality of life at both 3 and 12 months after lumbar decompression surgery. At 3 months postintervention, sedentary/inactive patients reported more leg pain and worse disability than patients who performed activities outside the home preoperatively. However, at 12 months postintervention, there were no statistically significant differences between the two cohorts in back pain, leg pain, quality of life, or disability. Multivariate analysis revealed that sedentary/inactive patients had improved disability and higher quality of life after surgery compared to baseline. Active patients experienced greater overall improvement in disability compared to inactive patients., Conclusions: Sedentary/inactive patients have a more protracted recovery after lumbar decompression surgery for spinal stenosis, but at 12 months postintervention can expect to reach similar long-term outcomes as patients who are active/perform activities outside the home preoperatively.

OBJECTIVE Lumbar spinal stenosis (LSS) is a common condition that leads to significant disability, particularly in the elderly. Current therapeutic options have certain drawbacks. This study evaluates the 5-year clinical and radiographic results of a minimally invasive pedicle-lengthening osteotomy (PLO) for symptomatic LSS. METHODS A prospective, single-arm, clinical pilot study was conducted involving 20 patients (mean age 61.7 years) with symptomatic LSS treated by a PLO procedure at 1 or 2 lumbar levels. All patients had symptoms of neurogenic claudication or radiculopathy secondary to LSS, and had not improved after a minimum 6-month course of nonoperative treatment. Eleven patients had a Meyerding grade I degenerative spondylolisthesis in addition to LSS. Clinical outcomes were measured using the Oswestry Disability Index, Zürich Claudication Questionnaire, 12-Item Short Form Health Survey, and a visual analog scale for back and leg pain. Procedural variables, neurological outcomes, adverse events, and radiological imaging (plain radiographs and CT scans) were collected at the 1.5-, 3-, 6-, 9-, 12-, 24-, and 60-month time points. RESULTS The PLOs were performed through percutaneous incisions, with minimal blood loss in all cases. There were no operative complications. Four adverse events occurred during the follow-up period. Statistically significant improvement was observed in each of the outcome instruments and maintained over the 5-year follow-up period. Imaging studies, reviewed by an independent radiologist, showed no evidence of device subsidence, migration, breakage, or heterotopic ossification. Thin-slice CT scans documented healing of the osteotomy site in all patients at the 6-month time point and an increase of 115% in the mean cross-sectional area of the spinal canal. CONCLUSIONS Treatment of patients with symptomatic LSS with a PLO procedure provided substantial enlargement of the area of the spinal canal and favorable clinical results for both disease-specific and non-disease-specific outcome measures at all follow-up time points out to 5 years. Future research is needed to compare this technique to alternative therapies for LSS.

OBJECTIVE Surgery for thoracic disc herniation and spinal canal stenosis is comparatively rare and often challenging. Individual planning and various surgical techniques and approaches are required. The key factors for selecting the technique and approach are anatomical location, consistency of the pathology, general condition of the patient, and the surgeon's experience. The objective of the study was to evaluate the technical implementation and outcomes of a full-endoscopic uniportal technique via the interlaminar, extraforaminal, or transthoracic retropleural approach in patients with symptomatic disc herniation and stenosis of the thoracic spine, taking specific advantages and disadvantages and literature into consideration. METHODS Between 2009 and 2015, decompression was performed in 55 patients with thoracic disc herniation or stenosis using a full-endoscopic uniportal technique via an interlaminar, extraforaminal, or transthoracic retropleural approach. Imaging and clinical data were collected during follow-up examinations for 18 months. RESULTS Sufficient decompression was achieved in the full-endoscopic uniportal technique. One patient required revision due to secondary bleeding, and another exhibited persistent deterioration on myelopathy. No other serious complications were observed. All but one patient experienced regression or improvement of their symptoms. CONCLUSIONS The full-endoscopic uniportal technique with an interlaminar, extraforaminal, or transthoracic retropleural approach was found to be a sufficient and minimally invasive method. To cover the entire range of thoracic disc herniations and stenosis within the criteria named, all full-endoscopic approaches are required.

OBJECTIVE Recommendations for the surgical treatment of isolated lumbar spinal stenosis (LSS) (i.e., in the absence of concomitant scoliosis or spondylolisthesis) are unclear. The aims of this study were to investigate trends in the surgical treatment of isolated LSS in US adults and determine implications for outcomes. METHODS The authors analyzed inpatient and outpatient claims from the Truven Health Analytics MarketScan Commercial Claims and Encounters Database for 20,279 patients aged 40-64 years who underwent surgery for LSS between 2010 and 2014. Only patients with continuous 12-month insurance coverage after surgery were included. The rates of decompression with arthrodesis versus decompression only and of simple (1- or 2-level, single-approach) versus complex (> 2-level or combined-approach) arthrodesis were analyzed by year and geographic region. These trends were further analyzed with respect to complications, length of hospital stay, payments made to the hospital, and patient discharge status. Statistical significance was set at p < 0.05. RESULTS The proportion of patients who underwent decompression with arthrodesis compared with decompression only increased significantly and linearly from 2010 to 2014 (OR 1.08; 95% CI 1.06-1.10). Arthrodesis was more likely to be complex rather than simple with each subsequent year (OR 1.4; 95% CI 1.33-1.49). This trend was accompanied by an increased likelihood of postoperative complications (OR 1.11; 95% CI 1.02-1.21), higher costs (payments increased by a mean of US$1633 per year; 95% CI 1327-1939), and greater likelihood of being discharged to a skilled nursing facility as opposed to home (OR 1.11; 95% CI 1.03-1.20). The South and Midwest regions of the US had the highest proportions of patients undergoing arthrodesis (48% and 42%, respectively). The mean length of hospital stay did not change significantly (p = 0.324). CONCLUSIONS From 2010 to 2014, the proportion of adults undergoing decompression with arthrodesis versus decompression only for the treatment of LSS increased, especially in the South and Midwest regions of the US. A greater proportion of these fusions were complex and were associated with more complications, higher costs, and a greater likelihood of being discharged to a skilled nursing facility.

Upper lumbar (L1-2, L2-3) disc herniations are distinct in their diffuse presenting clinical symptomatology and have poorer outcomes with surgical intervention than those following mid and lower lumbar disc herniations and disc surgery. The authors present the cases of 3 patients with L1-2 disc herniations and significant stenosis of the spinal canal. The surgical approach used here combined the principles of transforaminal percutaneous endoscopic discectomy and the extreme lateral lumbar interbody fusion procedures with intraoperative CT-guided navigational assistance. The approach provides a safe corridor of direct visualization to the ventral thecal sac with minimal bony resection and could, in principle, reduce neurological injury and biomechanical instability, which likely contribute to poor outcomes at this level.

The aim of this study was to report on 2 patients in whom metal-on-metal (MOM) facet replacements failed, with subsequent positive findings on allergy testing. Motion-preserving devices have been used with limited success when instrumentation is indicated in the mobile spine. MOM-bearing surfaces in orthopedics were developed to increase implant longevity, yet have been associated with numerous adverse outcomes, including local tissue reactions, pseudotumors, metallosis, and the need for revision surgery. Five patients with spinal stenosis and low-grade spondylolisthesis were randomized to undergo facet replacement surgery with the ACADIA facet replacement system at the authors' institution. Two patients experienced a return of neurological symptoms after a pain-free interval (< 2 years) with development of local tissue reaction and positive findings on allergy testing to cobalt, the metal in the MOM-bearing surface. Both patients underwent successful removal of the implant and revision to titanium posterior spinal fusion and interbody fusion without further complication. Motion-preserving devices have been designed and trialed for specific indications in the mobile spine. Given the adverse results from MOM devices in hip arthroplasty and now the early reports with MOM facet replacements, caution is warranted when moving forward with any MOM joint-bearing surface. Both patients presented here had an unusual tissue reaction locally and subsequent positive allergy testing results to cobalt. These 2 patients appear to have developed a delayed hypersensitivity reaction to the metal, likely from fine debris at the MOM interface.

This study was performed to describe the extraforaminal approach of biportal endoscopic spinal surgery (BESS) as a new endoscopic technique for transforaminal decompression and discectomy and to demonstrate the clinical outcomes of this new procedure for the first time. Twenty-one patients (27 segments) who underwent the extraforaminal approach of BESS between March 2015 and April 2016 were enrolled according to the inclusion and exclusion criteria. The operative time (minutes/level) and complications after the procedure were recorded. The visual analog scale (VAS) score was checked to assess the degree of radicular leg pain preoperatively and at the time of the last follow-up. The modified Macnab criteria were used to examine the clinical outcomes at the time of the last follow-up. The mean duration of the follow-up period was 14.8 months (minimum duration 12 months). The mean operative time was 96.7 minutes for one level. The mean VAS score for radicular leg pain dropped from a preoperative score of 7.5 ± 0.9 to a final follow-up score of 2.5 ± 1.2 (p < 0.001). The final outcome according to the modified Macnab criteria was excellent in 5 patients (23.8%), good in 12 (57.2%), fair in 4 (19.0%), and poor in 0. Therefore, excellent or good results (a satisfied outcome) were obtained in 80.9% of the patients. Complications were limited to one dural tear (4.8%). The authors found that the extraforaminal approach of BESS was a feasible and advantageous endoscopic technique for the treatment of foraminal lesions, including stenosis and disc herniation. They suggest that this technique represents a useful, alternative, minimally invasive method that can be used to treat lumbar foraminal stenosis and disc herniation.

Spinopelvic fixation provides an important anchor for long fusions in spinal deformity surgery, and it is also used in the treatment of other spine pathologies. Iliac screws are known to sometimes require reoperation due to pain resulting from hardware prominence and skin injury. S-2 alar/iliac (S2AI) screws do not often require removal, but they may provide inadequate fixation in select cases. In this paper the authors describe a technique for S-1 alar/iliac screws that may be used independently or as a supplement to S2AI screws. A preliminary biomechanical analysis and 2 clinical case examples are also provided.

OBJECTIVE Surgical decompression is extremely effective in relieving pain and symptoms due to lumbar spinal stenosis (LSS). Decompression with interlaminar stabilization (D+ILS) is as effective as decompression with posterolateral fusion for stenosis, as shown in a major US FDA pivotal trial. This study reports a multicenter, randomized controlled trial in which D+ILS was compared with decompression alone (DA) for treatment of moderate to severe LSS. METHODS Under approved institutional ethics review, 230 patients (1:1 ratio) randomized to either DA or D+ILS (coflex, Paradigm Spine) were treated at 7 sites in Germany. Patients had moderate to severe LSS at 1 or 2 adjacent segments from L-3 to L-5. Outcomes were evaluated up to 2 years postoperatively, including Oswestry Disability Index (ODI) scores, the presence of secondary surgery or lumbar injections, neurological status, and the presence of device- or procedure-related severe adverse events. The composite clinical success (CCS) was defined as combining all 4 of these outcomes, a success definition validated in a US FDA pivotal trial. Additional secondary end points included visual analog scale (VAS) scores, Zürich Claudication Questionnaire (ZCQ) scores, narcotic usage, walking tolerance, and radiographs. RESULTS The overall follow-up rate was 91% at 2 years. There were no significant differences in patient-reported outcomes at 24 months (p > 0.05). The CCS was superior for the D+ILS arm (p = 0.017). The risk of secondary intervention was 1.75 times higher among patients in the DA group than among those in the D+ILS group (p = 0.055). The DA arm had 228% more lumbar injections (4.5% for D+ILS vs 14.8% for DA; p = 0.0065) than the D+ILS one. Patients who underwent DA had a numerically higher rate of narcotic use at every time point postsurgically (16.7% for D+ILS vs 23% for DA at 24 months). Walking Distance Test results were statistically significantly different from baseline; the D+ILS group had > 2 times the improvement of the DA. The patients who underwent D+ILS had > 5 times the improvement from baseline compared with only 2 times the improvement from baseline for the DA group. Foraminal height and disc height were largely maintained in patients who underwent D+ILS, whereas patients treated with DA showed a significant decrease at 24 months postoperatively (p < 0.001). CONCLUSIONS This study showed no significant difference in the individual patient-reported outcomes (e.g., ODI, VAS, ZCQ) between the treatments when viewed in isolation. The CCS (survivorship, ODI success, absence of neurological deterioration or device- or procedure-related severe adverse events) is statistically superior for ILS. Microsurgical D+ILS increases walking distance, decreases compensatory pain management, and maintains radiographic foraminal height, extending the durability and sustainability of a decompression procedure. Clinical trial registration no.: NCT01316211 (clinicaltrials.gov).

OBJECTIVE Microsurgical decompression (MD) in patients with lumbar spinal stenosis (LSS) shows good clinical results. Nevertheless, 30%-40% of patients do not have a significant benefit after surgery-probably due to different anatomical preconditions. The sagittal profile types (SPTs 1-4) defined by Roussouly based on different spinopelvic parameters have been shown to influence spinal degeneration and surgical results. The aim of this study was to investigate the influence of the SPT on the clinical outcome in patients with LSS who were treated with MD. METHODS The authors retrospectively investigated 100 patients with LSS who received MD. The patients were subdivided into 4 groups depending on their SPT, which was determined from preoperative lateral spinal radiographs. The authors analyzed pre- and postoperative outcome scales, including the visual analog scale (VAS), walking distance, Oswestry Disability Index, Roland-Morris Disability Questionnaire, Odom's criteria, and the 36-Item Short Form Health Survey score. RESULTS Patients with SPT 1 showed a significantly worse clinical outcome concerning their postoperative back pain (VAS back-SPT 1 = 5.4 ± 2.8; VAS back-SPT 2 = 2.6 ± 1.9; VAS back-SPT 3 = 2.9 ± 2.6; VAS back-SPT 4 = 1.5 ± 2.5) and back pain-related disability. Only 43% were satisfied with their surgical results, compared with 70%-80% in the other groups. CONCLUSIONS A small pelvic incidence with reduced compensation mechanisms, a distinct lordosis in the lower lumbar spine with a high load on dorsal structures, and a long thoracolumbar kyphosis with a high axial load might lead to worse back pain after MD. Therefore, the indication for MD should be provided carefully, fusion can be considered, and other possible reasons for back pain should be thoroughly evaluated and treated.

OBJECTIVE Cervical disc arthroplasty (CDA) has been demonstrated to be as safe and effective as anterior cervical discectomy and fusion (ACDF) in the management of 1- and 2-level degenerative disc disease (DDD). However, there has been a lack of data to address the fundamental discrepancy between the two surgeries (CDA vs ACDF), and preservation versus elimination of motion, in the management of cervical myelopathy associated with congenital cervical stenosis (CCS). Although younger patients tend to benefit more from motion preservation, it is uncertain if CCS caused by multilevel DDD can be treated safely with CDA. METHODS Consecutive patients who underwent 3-level anterior cervical discectomy were retrospectively reviewed. Inclusion criteria were age less than 50 years, CCS (Pavlov ratio ≤ 0.82), symptomatic myelopathy correlated with DDD, and stenosis limited to 3 levels of the subaxial cervical (C3-7) spine. Exclusion criteria were ossification of the posterior longitudinal ligament, previous posterior decompression surgery (e.g., laminoplasty or laminectomy), osteoporosis, previous trauma, or other rheumatic diseases that might have caused the cervical myelopathy. All these patients who underwent 3-level discectomy were divided into 2 groups according to the strategies of management: preservation or elimination of motion (the hybrid-CDA group and the ACDF group). The hybrid-CDA group underwent 2-level CDA plus 1-level ACDF, whereas the ACDF group underwent 3-level ACDF. Clinical assessment was measured by the visual analog scales (VAS) for neck and arm pain, Japanese Orthopaedic Association (JOA) scores, and Nurick grades. Radiographic outcomes were measured using dynamic radiographs for evaluation of range of motion (ROM). RESULTS Thirty-seven patients, with a mean (± SD) age of 44.57 ± 5.10 years, were included in the final analysis. There was a male predominance in this series (78.4%, 29 male patients), and the mean follow-up duration was 2.37 ± 1.60 years. There were 20 patients in the hybrid-CDA group, and 17 in the ACDF group. Both groups demonstrated similar clinical improvement at 2 years' follow-up. These patients with 3-level stenosis experienced significant improvement after either type of surgery (hybrid-CDA and ACDF). There were no significant differences between the 2 groups at each of the follow-up visits postoperatively. The preoperative ROM over the operated subaxial levels was similar between both groups (21.9° vs 21.67°; p = 0.94). Postoperatively, the hybrid-CDA group had significantly greater ROM (10.65° vs 2.19°; p < 0.001) than the ACDF group. Complications, adverse events, and reoperations in both groups were similarly low. CONCLUSIONS Hybrid-CDA yielded similar clinical improvement to 3-level ACDF in patients with myelopathy caused by CCS. In this relatively young group of patients, hybrid-CDA demonstrated significantly more ROM than 3-level ACDF without adjacent-segment disease (ASD) at 2 years' follow-up. Therefore, hybrid-CDA appears to be an acceptable option in the management of CCS. The strategy of motion preservation yielded similar improvements of cervical myelopathy to motion elimination (i.e., ACDF) in patients with CCS, while the theoretical benefit of reducing ASD required further validation.

OBJECTIVE The object of this study was to determine the association between postoperative sagittal spinopelvic alignment and patient-rated outcome measures following decompression and fusion for lumbar degenerative spondylolisthesis. METHODS The authors identified a consecutive series of patients who had undergone surgery for lumbar degenerative spondylolisthesis between 2008 and 2012, with an average follow-up of 3 years (range 1-6 years). Surgery was performed to address the clinical symptoms of spinal stenosis, not global sagittal alignment. Sagittal alignment was only assessed postoperatively. Patients were divided into 2 groups based on a postoperative sagittal vertical axis (SVA) < 50 mm (well aligned) or ≥ 50 mm (poorly aligned). Baseline demographic, procedure, and outcome measures were compared between the groups. Postoperative outcome measures and postoperative spinopelvic parameters were compared between groups using analysis of covariance. RESULTS Of the 84 patients included in this study, 46.4% had an SVA < 50 mm. Multiple levels of spondylolisthesis (p = 0.044), spondylolisthesis at the L3-4 level (p = 0.046), and multiple levels treated with fusion (p = 0.028) were more common among patients in the group with an SVA ≥ 50 mm. Patients with an SVA ≥ 50 mm had a worse SF-36 physical component summary (PCS) score (p = 0.018), a worse Oswestry Disability Index (ODI; p = 0.043), and more back pain (p = 0.039) than those with an SVA < 50 mm after controlling for multiple levels of spondylolisthesis and multilevel fusion. The spinopelvic parameters differing between the < 50-mm and ≥ 50-mm groups included lumbar lordosis (LL; 56.4° ± 4.7° vs 49.8° ± 4.3°, respectively, p = 0.040) and LL < pelvic incidence ± 9° (51% vs 23.1%, respectively, p = 0.013) after controlling for type of surgical procedure. CONCLUSIONS Data in this study revealed that patient-rated outcome is influenced by the overall postoperative sagittal balance as defined by the SVA.

OBJECTIVE Prior studies have shown obesity to be associated with higher complication rates but equivalent clinical outcomes following lumbar spine surgery. These findings have been reproducible across lumbar spine surgery in general and for lumbar fusion specifically. Nevertheless, surgeons seem inclined to limit the extent of surgery, perhaps opting for decompression alone rather than decompression plus fusion, in obese patients. The purpose of this study was to ascertain any difference in clinical improvement or complication rates between obese and nonobese patients following decompression alone compared with decompression plus fusion for lumbar spinal stenosis (LSS). METHODS The Quality Outcomes Database (QOD), formerly known as the National Neurosurgery Quality and Outcomes Database (N 2 QOD), was queried for patients who had undergone decompression plus fusion (D+F group) versus decompression alone (D+0 group) for LSS and were stratified by a body mass index (BMI) ≥ 30 kg/m 2 (obese) or < 30 kg/m 2 (nonobese). Demographic, surgical, and health-related quality of life data were compared. RESULTS In the nonobese cohort, 947 patients underwent decompression alone and 319 underwent decompression plus fusion. In the obese cohort, 844 patients had decompression alone and 337 had decompression plus fusion. There were no significant differences in the Oswestry Disability Index score or in leg pain improvement at 12 months when comparing decompression with fusion to decompression without fusion in either obese or nonobese cohorts. However, absolute improvement in back pain was less in the obese group when decompression alone had been performed. Blood loss and operative time were lowest in the nonobese D+0 cohort and were higher in obese patients with or without fusion. Obese patients had a longer hospital stay (4.1 days) than the nonobese patients (3.3 days) when fusion had been performed. In-hospital stay was similar in both obese and nonobese D+0 cohorts. No significant differences were seen in 30-day readmission rates among the 4 cohorts. CONCLUSIONS Consistent with the prior literature, equivalent clinical outcomes were found among obese and non-obese patients treated for LSS. In addition, no difference in clinical outcomes as related to the extent of the surgical procedure was observed between obese and nonobese patients. Within the D+0 group, the nonobese patients had slightly better back pain scores at 2 years postoperatively. There may be a higher blood product requirement in obese patients following spine surgery, as well as an extended hospital stay, when fusion is performed. While obesity may influence the decision for or against surgery, the data suggest that obesity should not necessarily alter the appropriate procedure for well-selected surgical candidates.

Advancements in the understanding of adult spinal deformity have led to a greater awareness of the role of the pelvis in maintaining sagittal balance and alignment. Pelvic incidence has emerged as a key radiographic measure and should closely match lumbar lordosis. As proper measurement of the pelvic incidence requires accurate identification of the S-1 endplate, lumbosacral transitional anatomy may lead to errors. The purpose of this study is to demonstrate how lumbosacral transitional anatomy may lead to errors in the measurement of pelvic parameters. The current case highlights one of the potential complications that can be avoided with awareness. The authors report the case of a 61-year-old man who had undergone prior lumbar surgeries and then presented with symptomatic lumbar stenosis and sagittal malalignment. Radiographs showed a lumbarized S-1. Prior numbering of the segments in previous surgical and radiology reports led to a pelvic incidence calculation of 61°. Corrected numbering of the segments using the lumbarized S-1 endplate led to a pelvic incidence calculation of 48°. Without recognition of the lumbosacral anatomy, overcorrection of the lumbar lordosis might have led to negative sagittal balance and the propensity to develop proximal junction failure. This case illustrates that improper identification of lumbosacral transitional anatomy may lead to errors that could affect clinical outcome. Awareness of this potential error may help improve patient outcomes.

OBJECTIVE The relief of leg symptoms by surgical decompression for lumbar stenosis is well supported by the literature. Less is known about the effect on back pain. Some surgeons believe that the relief of back pain should not be an expected outcome of decompression and that substantial back pain may be a contraindication to decompression only; therefore, stabilization may be recommended for patients with substantial preoperative back pain even in the absence of well-accepted indications for stabilization such as spondylolisthesis, scoliosis, or sagittal malalignment. The purpose of this study is to determine if patients with lumbar stenosis and substantial back pain-in the absence of spondylolisthesis, scoliosis, or sagittal malalignment-can obtain significant improvement after decompression without fusion or stabilization. METHODS Analysis of the National Neurosurgery Quality and Outcomes Database (N 2 QOD) identified 726 patients with lumbar stenosis (without spondylolisthesis or scoliosis) and a baseline back pain score ≥ 5 of 10 who underwent surgical decompression only. No patient was reported to have significant spondylolisthesis, scoliosis, or sagittal malalignment. Standard demographic and surgical variables were collected, as well as patient outcomes including back and leg pain scores, Oswestry Disability Index (ODI), and EuroQoL 5D (EQ-5D) at baseline and 3 and 12 months postoperatively. RESULTS The mean age of the cohort was 65.6 years, and 407 (56%) patients were male. The mean body mass index was 30.2 kg/m 2 , and 40% of patients had 2-level decompression, 29% had 3-level decompression, 24% had 1-level decompression, and 6% had 4-level decompression. The mean estimated blood loss was 130 ml. The mean operative time was 100.85 minutes. The vast majority of discharges (88%) were routine home discharges. At 3 and 12 months postoperatively, there were significant improvements from baseline for back pain (7.62 to 3.19 to 3.66), leg pain (7.23 to 2.85 to 3.07), EQ-5D (0.55 to 0.76 to 0.75), and ODI (49.11 to 27.20 to 26.38). CONCLUSIONS Through the 1st postoperative year, patients with lumbar stenosis-without spondylolisthesis, scoliosis, or sagittal malalignment-and clinically significant back pain improved after decompression-only surgery.

OBJECTIVE Prospective longitudinal outcomes registries are at the center of evidence-driven health care reform. Obtaining real-world outcomes data at 12 months can be costly and challenging. In the present study, the authors analyzed whether 3-month outcome measurements sufficiently represent 12-month outcomes for patients with degenerative lumbar disease undergoing surgery. METHODS Data from 3073 patients undergoing elective spine surgery for degenerative lumbar disease were entered into a prospective multicenter registry (N(2)QOD). Baseline, 3-month, and 12-month follow-up Oswestry Disability Index (ODI) scores were recorded. The absolute differences between actual 12- and 3-month ODI scores was evaluated. Additionally, the authors analyzed the absolute difference between actual 12-month ODI scores and a model-predicted 12-month ODI score (the model used patients' baseline characteristics and actual 3-month scores). The minimal clinically important difference (MCID) for ODI of 12.8 points and the substantial clinical benefit (SCB) for ODI of 18.8 points were used based on the previously published values. The concordance rate of achieving MCID and SCB for ODI at 3-and 12-months was computed. RESULTS The 3-month ODI scores differed from 12-month scores by an absolute difference of 11.9 ± 10.8, and predictive modeling estimations of 12-month ODI scores differed from actual 12-month scores by a mean (± SD) of 10.7 ± 9.0 points (p = 0.001). Sixty-four percent of patients (n = 1982) achieved an MCID for ODI at 3 months in comparison with 67% of patients (n = 2088) by 12 months; 51% (n = 1731) and 61% (n = 1860) of patients achieved SCB for ODI at 3 months and 12 months, respectively. Almost 20% of patients had ODI scores that varied at least 20 points (the point span of an ODI functional category) between actual 3- and 12-month values. In the aggregate analysis of achieving MCID, 77% of patients were concordant and 23% were discordant in achieving or not achieving MCID at 3 and 12 months. The discordance rates of achieving or not achieving MCID for ODI were in the range of 19% to 27% for all diagnoses and treatments (decompression with and without fusion). The positive and negative predictive value of 3-months ODI to predict 12-month ODI was 86% and 60% for MCID and 82% and 67% for SCB. CONCLUSIONS Based on their findings, the authors conclude the following: 1) Predictive methods for functional outcome based on early patient experience (i.e., baseline and/or 3-month data) should be used to help evaluate the effectiveness of procedures in patient populations, rather than serving as a proxy for long-term individual patient experience. 2) Prospective longitudinal registries need to span at least 12 months to determine the effectiveness of spine care at the individual patient and practitioner level.

OBJECTIVE Little is known about the relationship between sagittal spinal alignment in patients with lumbar spinal canal stenosis (LSS) and objective findings such as spinopelvic parameters, lumbar back muscle degeneration, and clinical data. The purpose of this study was to identify the preoperative clinical and radiological factors that predict improvement in sagittal spinal alignment after decompressive surgery in patients with LSS. METHODS The records of 61 patients with LSS who underwent microendoscopic laminotomy and had pre- and postoperative clinical data collected were retrospectively reviewed. Spinopelvic parameters, including sagittal vertical axis (SVA), lumbar lordosis (LL), sacral slope, pelvic tilt, and pelvic incidence (PI), were evaluated. On T2-weighted MRI, the cross-sectional area and the percentage of fat infiltration of the paravertebral muscles (PVMs) before surgery were calculated. For patients with preoperative SVA > 40 mm (n = 30), the correlation between SVA improvement and preoperative clinical and radiographic parameters was calculated. RESULTS SVA improvement correlated with preoperative LL (r = -0.39) and PI -LL (r = 0.54). Multiple regression analysis showed that preoperative PI -LL (beta = 0.62; p < 0.01) and symptom duration (beta = -0.40; p < 0.05) were independently associated with SVA improvement. The percentage of fat infiltration of the PVM at L4-5 was significantly greater in patients with preoperative SVA ≥ 40 mm than in those patients with SVA < 40 mm. CONCLUSIONS Preoperative PI -LL and symptom duration were independently associated with SVA improvement in LSS patients with forward-bending posture. PVM degeneration at the lower lumbar level was significantly greater among patients with preoperative SVA ≥ 40 mm than in patients with SVA < 40 mm.

In the conventional posterior approach to the lumbar spine, the lamina is exposed by stripping the paravertebral muscles from the spinous process, and the resulting paravertebral muscle damage can produce muscle atrophy and decreased muscle strength. The author developed a novel surgical approach to the lumbar spine in which the attachment of the paravertebral muscles to the spinous process is preserved. In the novel approach, the spinous process is split on the midline without stripping the attached muscles, and a hemilateral half of the spinous process is then resected at the base, exposing only the ipsilateral lamina. Before closing, the resected half is sutured and reattached to the remaining half of the spinous process. Thirty-eight patients with lumbar spinal canal stenosis (LSCS) undergoing unilateral partial laminectomy and bilateral decompression using this novel approach were analyzed. Postoperative changes in the multifidus muscle were evaluated by T2 signal intensity on MR images. MRI performed 1 year after the operation revealed no significant difference in the T2 signal intensity of the multifidus muscle between the approach and nonapproach sides. This result indicated that postoperative changes of the multifidus muscle on the approach side were slight. The clinical outcomes of unilateral partial laminectomy and bilateral decompression using this approach for LSCS were satisfactory. The novel approach can be a useful alternative to the conventional posterior lumbar approach.

Objective: The use of conventional uniportal spinal endoscopic decompression surgery for lumbar spinal stenosis can be limited by technical difficulties and a restricted field of vision. The purpose of this study is to describe the technique for percutaneous biportal endoscopic decompression (PBED) for lumbar spinal stenosis and analysis of clinical postoperative results., Methods: The authors performed a unilateral laminotomy with bilateral foraminal decompression using a unilateral biportal endoscopic system in patients with single-level lumbar stenosis. The authors enrolled only patients who underwent follow-up for longer than 12 months after PBED. Fifty-eight patients were enrolled in this study. This approach was based on 2 portals: one portal was used for continuous irrigation and endoscopic viewing and the other portal was used to manipulate the instruments used in the decompression procedures. Clinical parameters such as the Oswestry Disability Index (ODI), Macnab criteria, and postoperative complications were analyzed., Results: Neural decompression was effectively performed in all enrolled patients. The mean ODI was significantly lower after PBED. Of 58 patients, 47 (81.0%) had a good or excellent result according to the Macnab criteria. Postoperative ODI and visual analog scale scores were significantly improved compared with preoperative values., Conclusions: From a surgical point of view, percutaneous biportal endoscopy is very similar to microscopic spinal surgery, permitting good visualization of the contralateral sublaminar and medial foraminal areas. The authors suggest that the PBED, which is a minimally invasive procedure, is an alternative treatment option for degenerative lumbar stenosis.

Object: Lumbar discectomy is one of the most common surgical spine procedures. In order to understand the value of this surgical care, it is important to understand the costs to the health care system and patient for good results. The objective of this study was to evaluate for the first time the cost-effectiveness of spine surgery in Latin America for lumbar discectomy in terms of cost per quality-adjusted life year (QALY) gained for patients in Brazil., Methods: The authors performed a prospective cohort study involving 143 consecutive patients who underwent open discectomy for lumbar disc herniation (LDH). Patient-reported outcomes were assessed utilizing the SF-6D, which is derived from a 12-month variation of the SF-36. Direct medical costs included medical reimbursement, costs of hospital care, and overall resource consumption. Disability losses were considered indirect costs. A 4-year horizon with 3% discounting was applied to health-utilities estimates. Sensitivity analysis was performed by varying utility gain by 20%. The costs were expressed in Reais (R$) and US dollars ($), applying an exchange rate of 2.4:1 (the rate at the time of manuscript preparation)., Results: The direct and indirect costs of open lumbar discectomy were estimated at an average of R$3426.72 ($1427.80) and R$2027.67 ($844.86), respectively. The mean total cost of treatment was estimated at R$5454.40 ($2272.66) (SD R$2709.17 [$1128.82]). The SF-6D utility gain was 0.044 (95% CI 0.03197-0.05923, p = 0.017) at 12 months. The 4-year discounted QALY gain was 0.176928. The estimated cost-utility ratio was R$30,828.35 ($12,845.14) per QALY gained. The sensitivity analysis showed a range of R$25,690.29 ($10,714.28) to R$38,535.44 ($16,056.43) per QALY gained., Conclusions: The use of open lumbar discectomy to treat LDH is associated with a significant improvement in patient outcomes as measured by the SF-6D. Open lumbar discectomy performed in the Brazilian supplementary health care system provides a cost-utility ratio of R$30,828.35 ($12,845.14) per QALY. The value of acceptable cost-effectiveness will vary by country and region.

Object: In this study, the authors aimed to identify specific risk factors for postdecompression lumbar disc herniation (PDLDH) in patients who have not undergone discectomy and/or fusion., Methods: Between 2007 and 2012, 493 patients with lumbar spinal stenosis underwent bilateral partial laminectomy without discectomy and/or fusion in a single hospital. Eighteen patients (herniation group [H group]: 15 men, 3 women; mean age 65.1 years) developed acute sciatica as a result of PDLDH within 2 years after surgery. Ninety patients who did not develop postoperative acute sciatica were selected as a control group (C group: 75 men, 15 women; mean age 65.4 years). Patients in the C group were age and sex matched with those in the H group. The patients in the groups were also matched for decompression level, number of decompression levels, and surgery date. The radiographic variables measured included percentage of slippage, intervertebral angle, range of motion, lumbar lordosis, disc height, facet angle, extent of facet removal, facet degeneration, disc degeneration, and vertebral endplate degeneration. The threshold for PDLDH risk factors was evaluated using a continuous numerical variable and receiver operating characteristic curve analysis. The area under the curve was used to determine the diagnostic performance, and values greater than 0.75 were considered to represent good performance., Results: Multivariate analysis revealed that preoperative retrolisthesis during extension was the sole significant independent risk factor for PDLDH. The area under the curve for preoperative retrolisthesis during extension was 0.849; the cutoff value was estimated to be a retrolisthesis of 7.2% during extension., Conclusions: The authors observed that bilateral partial laminectomy, performed along with the removal of the posterior support ligament, may not be suitable for lumbar spinal stenosis patients with preoperative retrolisthesis greater than 7.2% during extension.