Minimally invasive decompression versus open laminectomy for central stenosis of the lumbar spine: pragmatic comparative effectiveness study

Uniportal Versus Biportal Endoscopic Decompression for the Treatment of Lumbar Spinal Stenosis: A Systematic Review and Updated Meta-Analysis

Study DesignSystematic review and meta-analysis.ObjectiveAlthough uniportal and biportal endoscopic decompression have emerged as promising minimally invasive options for the management of lumbar spinal stenosis (LSS), their relative advantages remain debated. This systematic review and meta-analysis aims to evaluate the efficacy and safety of both approaches in LSS treatment.MethodsIn adherence to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines, we systematically searched PubMed, Embase, Cochrane Library, and Web of science for randomized controlled trials and observational studies comparing the outcomes of uniportal and biportal endoscopic techniques for LSS treatment. Meta-analysis was performed using a random-effects model.ResultsA total of 11 studies were included, comprising 1199 patients. Biportal endoscopy was associated with a significantly lower operation time (P < .01), Oswestry Disability Index (ODI) at 12 months (P < .01), and higher postoperative dural sac area (P < .01) and dural sac area expansion (P = .02). There were no significant differences between groups in intraoperative blood loss, hospitalization time, back pain, leg pain, or ODI at other timepoints, ipsilateral facetectomy angle, and overall complications, including dural tear, infection, postoperative hematoma, lower limb numbness, and nerve root injury.ConclusionIn this meta-analysis, biportal endoscopic decompression demonstrated significantly lower operation time, ODI at 12 months, and higher postoperative dural sac area and dural sac area expansion, although both techniques showed similar safety profiles and complication rates. Further high-quality studies are needed to better assess the advantages of both techniques for LSS treatment.

Bibliometric Patent Review of Minimally Invasive Spine Surgery

STUDY DESIGN

This study analyzes patents associated with minimally invasive spine surgery (MISS) found on the Lens open online platform.

OBJECTIVE

The goal of this research was to provide an overview of the most referenced patents in the field of MISS and to uncover patterns in the evolution and categorization of these patents.

SUMMARY OF BACKGROUND DATA

MISS has rapidly progressed, with a core focus on minimizing surgical damage, preserving the natural anatomy, and enabling swift recovery, all while achieving outcomes that rival traditional open surgery. While prior studies have primarily concentrated on MISS outcomes, the analysis of MISS patents has been limited.

METHODS

To conduct this study, we used the Lens platform to search for patents that included the terms "minimally invasive" and "spine" in their titles, abstracts, or claims. We then categorized these patents and identified the top 100 with the most forward citations. We further classified these patents into 4 categories: Spinal Stabilization Systems, Joint Implants or Procedures, Screw Delivery System or Method, and Access and Surgical Pathway Formation.

RESULTS

Five hundred two MISS patents were identified initially, and 276 were retained following a screening process. Among the top 100 patents, the majority had active legal status. The largest category within the top 100 patents was Access and Surgical Pathway Formation, closely followed by Spinal Stabilization Systems and Joint Implants or Procedures. The smallest category was Screw Delivery System or Method. Notably, the majority of the top 100 patents had priority years falling between 2000 and 2009, indicating a moderate positive correlation between patent rank and priority year.

CONCLUSIONS

Thus far, patents related to Access and Surgical Pathway Formation have laid the foundation for subsequent innovations in Spinal Stabilization Systems and Screw Technology. This study serves as a valuable resource for guiding future innovations in this rapidly evolving field.

Medical Digital Twin: A Review on Technical Principles and Clinical Applications

The usage of digital twins (DTs) is growing across a wide range of businesses. The health sector is one area where DT use has recently increased. Ultimately, the concept of digital health twins holds the potential to enhance human existence by transforming disease prevention, health preservation, diagnosis, treatment, and management. Big data's explosive expansion, combined with ongoing developments in data science (DS) and artificial intelligence (AI), might greatly speed up research and development by supplying crucial data, a strong cyber technical infrastructure, and scientific know-how. The field of healthcare applications is still in its infancy, despite the fact that there are several DT programs in the military and industry. This review's aim is to present this cutting-edge technology, which focuses on neurology, as one of the most exciting new developments in the medical industry. Through innovative research and development in DT technology, we anticipate the formation of a global cooperative effort among stakeholders to improve health care and the standard of living for millions of people globally.

A comparative analysis of unilateral biportal endoscopic and open laminectomy in multilevel lumbar stenosis

Background

Approximately 103 million people across the globe suffer from symptomatic lumbar spinal stenosis, impacting their health and quality of life. The unilateral biportal endoscopic technique is effective for treating single-segment degenerative lumbar spinal stenosis and is seen as a viable alternative to traditional open lumbar laminectomy. However, research on the application of this technique for multilevel lumbar spinal stenosis remains lacking.

Objective

To compare the clinical effects of unilateral biportal endoscopy (UBE) and open lumbar decompression (OLD) in the treatment of multilevel lumbar spinal stenosis (MLSS).

Methods

This retrospective study was conducted from February 2019 to December 2023 and compared the outcomes of Multilevel UBE surgery to OLD. The included patients were divided into two groups, namely the UBE group (n = 42, 86 surgical segments) and the OLD group (n = 40, 82 surgical segments). At the 1-year follow-up, the imaging findings, visual analogue scale (VAS), Oswestry disability index (ODI), and Zurich Claudication Questionnaire (ZCQ) were assessed. MRI measurements of the dural sac (CSA) and paravertebral cross-sectional area (PMA) were taken before surgery and at the final follow-up.

Results

The surgical segments of the two groups primarily consisted of adjacent segments (UBE 78.6% vs. OLD 78.8%), with a higher proportion of bilateral decompression in the OLD group (UBE 24.4% vs. OLD 28.0%). Preoperative imaging evaluation indicated a higher prevalence of grade C (severe stenosis) compared to grade D (severe stenosis) in both groups (UBE 74.4% vs. OLD 72%). The OLD group exhibited significantly greater blood loss compared to the UBE group (147.63 ± 26.55 vs. 46.19 ± 25.25 mL, p < 0.001). In addition, the duration of hospitalization in the OLD group was notably longer compared to the UBE group (7.58 ± 1.39 vs. 4.38 ± 1.56 days, p < 0.05). Paravertebral muscle atrophy (PMA) in the UBE group was significantly lower than in the OLD group (3.49 ± 3.03 vs. 5.58 ± 3.00, p < 0.05). Significantly elevated serum creatine kinase (CK) levels were observed in both groups, peaking at 1-day post-surgery, with the UBE group showing significantly lower levels than the OLD group (108.1 ± 12.2 vs. 364.13 ± 20.24 U/L, p < 0.05). On postoperative day 7, a significant decrease in liver enzyme levels was found in UBE group compared to the preoperative levels (61.81 ± 7.14 vs. 66.10 ± 8.26 U/L, p < 0.05). The Oswestry Disability Index (ODI) and Zurich Claudication Questionnaire (ZCQ) scores at 1 week, 6 months, and 1 year post-operation showed significant improvement compared to the preoperative scores in both groups (p < 0.05). The study found statistically significant differences in both the Visual Analog Scale (VAS) score (2.28 ± 0.59 vs. 2.85 ± 0.74, p < 0.05) and the Oswestry Disability Index (ODI) score (36.28 ± 2.03 vs. 37.57 ± 1.98, p < 0.05) at 1 week post-surgery between the two groups. However, no significant variations in scores were noted between preoperative and postoperative time points at other follow-up intervals.

Conclusion

The unilateral biportal endoscopic technique was applied to treat multilevel lumbar spinal stenosis, demonstrating decreased intraoperative bleeding and lower postoperative muscle-related complications compared to open lumbar decompression. Furthermore, UBE was found to promote early mobilization.

Open laminectomy vs. minimally invasive laminectomy for lumbar spinal stenosis: a review

Objectives

Lumbar spinal stenosis (LSS) refers to a narrowing of the space within the spinal canal, which can occur at any level but is most common in the lumbar spine. Open laminectomy and minimally invasive laminectomy (MIL) procedures are the most common surgical gold standard techniques for treating LSS. This study aims to review clinical and biomechanical literature to draw comparisons between open laminectomy and various MIL techniques. The MIL variation comprises microendoscopic decompression laminotomy, unilateral partial hemilaminectomy, and microendoscopic laminectomy.

Methods

A review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We reviewed 25 clinical, 6 finite element, and 3 cadaveric studies associated with treating LSS. We reviewed literature that discusses factors such as operation time, length of hospital stay, postoperative complications, reoperation rate, effect on elderly patients, patients' satisfaction, and adjacent segment disease degeneration for the clinical studies, whereas the range of motion (ROM), von Mises stresses, and stability was compared in biomechanical studies.

Results

MIL involves less bone and ligament removal, resulting in shorter hospital stays and lower reoperation and complication rates than open laminectomy. It improves the quality of health-related living standards and reduces postoperative pain. Biomechanical studies suggest that laminectomy and facetectomy increase annulus stress and ROM, leading to segmental instability.

Conclusion

Although theoretically, MIL means less tissue injury, pain, and faster recovery in the short term, the long-term results depend on the adequacy of the decompression procedure and tend to be independent of MIL or open laminectomy.

Comparative efficacy of unilateral biportal and percutaneous endoscopic techniques in unilateral laminectomy for bilateral decompression (ULBD) for lumbar spinal stenosis

BACKGROUND

Unilateral laminotomy for bilateral decompression (ULBD) has yielded positive results in the treatment of lumbar spinal stenosis (LSS). Unilateral biportal ULBD (UB-ULBD) and percutaneous endoscopic ULBD (PE-ULBD) are gaining popularity because of the progress that has been made in minimally invasive surgery (MIS). The objective of this study was to evaluate and compare the radiographic and clinical results of UB-ULBD and PE-ULBD.

METHODS

This study retrospectively enrolled patients who underwent ULBD surgery for LSS. The patients were categorized into two groups on the basis of the surgical method: the UB-ULBD group and the PE-ULBD group. Data on the general demographic data, surgical details, clinical efficacy, radiography and complications were compared between the two groups were compared. The minimum follow-up duration was 12 months.

RESULTS

A total of 113 LSS patients who had undergone ULBD at our institution were included, of whom 61 patients underwent UB-ULBD surgery and 52 underwent PE-ULBD surgery. The UB-ULBD group had a significantly shorter operation time (P < 0.05). The facet was significantly better preserved in the UB-ULBD group than in the PE-ULBD group, and the angle of ipsilateral facet joint resection in the UE-ULBD group was significantly smaller (P < 0.05). The ODI score, VAS score and modified Macnab criteria improved postoperatively in both groups. The UB-ULBD group had a 95.08% rate of excellent or good patient outcomes, whereas the PE-ULBD group had a 92.30% rate.

CONCLUSION

Both UB-ULBD and PE-ULBD can provide favourable clinical outcomes when used to treat LSS. UB-ULBD is beneficial because of its shorter operation time, smaller angle of ipsilateral facet joint resection and better facet preservation, making it a viable and safe option for treating LSS while ensuring spinal stability.

New ipsilateral full endoscopic interlaminar approach for L5-S1 foraminal and extraforaminal decompression: technique description and initial case series

BACKGROUND

The L5-S1 interlaminar access described in 2006 by Ruetten et al. represented a paradigm shift and a new perspective on endoscopic spinal approaches. Since then, the spinal community has shown that both the traditional ipsilateral and novel contralateral interlaminar approaches to the L5-S1 foramen are good alternatives to transforaminal access. This study aimed to provide a technical description and brief case series analysis of a new endoscopic foraminal and extraforaminal approach for pathologies at the lumbar L5-S1 level using a new ipsilateral interlaminar approach.

METHODS

Thirty patients with degenerative stenotic conditions at the L5-S1 disc level underwent the modified interlaminar approach. The surgical time, blood loss, occurrence of complications, and clinical outcomes were recorded. The data were compiled in Excel and analyzed using R software version 4.2. All continuous variables are presented as the mean, median, minimum, and maximal ranges. For categorical variables, data are described as counts and percentages.

RESULTS

Thirty patients were included in the study. The cohort showed significant improvements in all quality-of-life scores (ODI, visual analog scale of back pain, and visual analog scale of leg pain). Five cases of postoperative numbness and three cases of postoperative dysesthesia have been reported. No case of durotomy or leg weakness has been reported.

CONCLUSIONS

The fundamental change proposed by this procedure, the new ipsilateral approach, presents potential advantages to surgeons by overcoming anatomical challenges at the L5-S1 level and by providing surgeon-friendly visualization and access. This approach allows for extensive foraminal and extraforaminal decompression, including the removal of hernias and osteophytosis, without causing neural retraction of the L5-S1 roots while maintaining the stability of the operated level.

Functional outcome after introduction of hemilaminectomy in management of spinal schwannomas and meningiomas

Background

Schwannomas and meningiomas are intradural extramedullary spinal tumors which are regularly encountered in the neurosurgical clinic. These tumors cause neurological deficit by compression on the spinal cord and commonly pain when affecting the cauda equina. The traditional treatment with standard laminectomy (SL) can cause instability to the dorsal segments of the spinal column, and the less invasive option of hemilaminectomy (HL) has therefore been developed. We aim in this study to investigate transition from SL to HL in a population-based cohort.

Methods

Adult patients (18 years and older) undergoing primary surgery due to spinal meningioma or schwannoma between 2007 and 2022 at the neurosurgical clinic were included. Data related to clinical, surgical and outcome variables were retrospectively collected.

Results

A total of 187 patients were identified: 155 in the SL group, 26 in the HL group and in 6 patients a combination of SL and HL. The mean age of the SL group was 62.7 years (SD14.2) compared to 58.0 (SD15.7) in the HL group (p = 0.16). Preoperative motor deficit was more common in SL group compared to HL group (76.8 % and 61.5 %, respectively, p = 0.14). Thoracal location was most common for both groups (SL 65.8 % and HL 61.5 %). Postoperative change in McCormick grades and early complications were similar between groups.

Conclusion

Outcome after hemilaminectomy due to intradural extramedullary schwannoma or meningioma is comparable to standard laminectomy with regards to postoperative complications and neurological improvement. Our findings support the transition to hemilaminectomy in selected cases.

Decompression alone or with fusion for degenerative lumbar spondylolisthesis (Nordsten-DS): five year follow-up of a randomised, multicentre, non-inferiority trial

OBJECTIVE

To assess whether decompression alone is non-inferior to decompression with instrumented fusion five years after primary surgery in patients with degenerative lumbar spondylolisthesis.

DESIGN

Five year follow-up of a randomised, multicentre, non-inferiority trial (Nordsten-DS).

SETTING

16 public orthopaedic and neurosurgical clinics in Norway.

PARTICIPANTS

Patients aged 18-80 years with symptomatic lumbar spinal stenosis and a spondylolisthesis of 3 mm or more at the stenotic level.

INTERVENTIONS

Decompression surgery alone and decompression with additional instrumented fusion (1:1).

MAIN OUTCOME MEASURES

The primary outcome was a 30% or more reduction in Oswestry disability index from baseline to five year follow-up. The predefined non-inferiority margin was a -15 percentage point difference in the proportion of patients who met the primary outcome. Secondary outcomes included the mean change in Oswestry disability index, Zurich claudication questionnaire, numeric rating scale for leg and back pain, and EuroQol Group 5-Dimension (EQ-5D-3L) questionnaire.

RESULTS

From 12 February 2014 to 18 December 2017, 267 participants were randomly assigned to decompression alone (n=134) and decompression with instrumented fusion (n=133). Of these, 230 (88%) responded to the five year questionnaire: 121 in the decompression group and 109 in the fusion group. Mean age at baseline was 66.2 years (SD 7.6), and 69% were women. In the modified intention-to-treat analysis with multiple imputation of missing data, 84 (63%) of 133 people in the decompression alone group and 81 (63%) of 129 people in the fusion group had a at least a 30% reduction in Oswestry disability index, a difference of 0.4 percentage points. (95% confidence interval (CI) -11.2 to 11.9). The respective results of the per protocol analysis were 65 (65%) of 100 in the decompression alone group and 59 (66%) of 89 in the fusion group, a difference of -1.3 percentage points (95% CI -14.5 to 12.2). Both 95% CIs were higher than the predefined non-inferiority margin of -15%. The mean change in Oswestry disability index from baseline to five years was -17.8 in both groups (mean difference 0.02 (95% CI -3.8 to 3.9)). Results of the other secondary outcomes were in the same direction as the primary outcome. From two to five year follow-up, a new lumbar operation occurred in six (5%) of 123 people in the decompression group and 11 (10%) of 113 people in the fusion group, with a total from baseline to five years of 21 (16%) of 129 people and 23 (18%) of 125, respectively.

CONCLUSIONS

In participants with degenerative spondylolisthesis, decompression alone was non-inferior to decompression with instrumented fusion five years after primary surgery. Proportions of subsequent surgeries at the index level or an adjacent lumbar level were no different between the groups.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02051374.

Degenerative Spinal Stenosis and Ipsi-Contralateral Decompression: Presentation of a Surgical Technique and Clinical Cases

Lumbar spinal stenosis is a widespread condition that significantly affects the quality of life in elderly individuals. Conservative therapy has a positive effect on patients whose primary symptom is pain. However, in severe cases with the presence of hypesthesia and paresis, surgical treatment comes into consideration. The aim of surgery is to decompress the neurovascular elements compressed by the narrowed spinal canal while preserving spinal stability. Conventional laminectomy, with or without fusion, has been considered effective for the treatment of this pathology, but its drawbacks are significant, including tissue trauma, secondary instability, and a substantial percentage of reoperations due to complications. In recent years, various minimally invasive spine surgery techniques have emerged, showing comparable results to laminectomy decompression in terms of relieving symptomatic spinal stenosis. Additionally, these techniques offer significant benefits such as minimal tissue trauma, reduced complication rates, and shorter operative time and recovery periods. Given the continuous development and improvement, minimally invasive surgery is expected to widely replace traditional open surgery for the treatment of lumbar stenosis in the future. In this article, we present our experience in the surgical treatment of patients with degenerative lumbar stenosis, detailing the technique of the minimally invasive procedure we utilize and highlighting some of the clinical cases in which it has been applied.

Novel Combination of Lateral Interbody Fusion and Endoscopic Ipsi-Contra Decompression for Severe Stenosis From Lumbar Spondylolisthesis: A Case Report

Minimally invasive surgical approaches to the spine that leverage indirect decompression are gaining increasing popularity. While there is excellent literature on the value of indirect decompression, there are limitations to this procedure. Specifically, in patients with severe stenosis and neurogenic claudication, there is a concern among many surgeons regarding the adequacy of indirect decompression alone. In these cases, the lateral approach is often abandoned in favor of an open posterior or posterior minimally invasive approach. Unfortunately, some of the distinct benefits of the direct lateral approach are then lost. Here, we present the case of a 58-year-old male who underwent an L4-L5 lateral interbody fusion with an endoscopic ipsi-contra decompression to achieve both direct and indirect treatment of severe neuroforaminal and central stenosis. From this strategy, this patient had complete pre-operative symptom resolution and was able to return to work immediately after surgery without significant restriction. Combining the benefits of direct and indirect using an ultra-minimally invasive decompressive approach offers a potential solution.

Time Course of Asymptomatic Stenosis in Multiple Lumbar Spinal Stenosis-Five-Year Results of Selective Decompression of Symptomatic Levels

Background: In the diagnosis of lumbar spinal stenosis (LSS), finding stenosis with magnetic resonance imaging (MRI) does not always correlate with symptoms such as sciatica or intermittent claudication. We perform decompression surgery only for cases where the levels diagnosed from neurological findings are symptomatic, even if multiple stenoses are observed on MRI. The objective of this study was to examine the time course of asymptomatic stenosis in patients with LSS after they underwent decompression surgery for symptomatic stenosis. Materials and Methods: The participants in this study comprised 137 LSS patients who underwent single-level L4-5 decompression surgery from 2003 to 2013. The dural sac cross-sectional area at the L3-4 disc level was calculated based on preoperative MRI. A cross-sectional area less than 50 mm2 was defined as stenosis. The patients were grouped, according to additional spinal stenosis at the L3-4 level, into a double group (16 cases) with L3-4 stenosis, and a single group (121 cases) without L3-4 stenosis. Incidences of new-onset symptoms originating from L3-4 and additional L3-4-level surgery were examined. Results: Five years after surgery, 98 cases (72%) completed follow-up. During follow-up, 2 of 12 patients in the double group (16.7%) and 9 of 86 patients in the single group (10.5%) presented with new-onset symptoms originating from L3-4, showing no significant difference between groups. Additional L3-4 surgery was performed for one patient (8.3%) in the double group and three patients (3.5%) in the single group; again, no significant difference was shown. Conclusion: Patients with asymptomatic L3-4 stenosis on preoperative MRI were not prone to develop new symptoms or need additional L3-4-level surgery within 5 years after surgery when compared to patients without preoperative L3-4 stenosis. These results indicate that prophylactic decompression for asymptomatic levels is unnecessary.

Surgical site infection rates in open versus endoscopic lumbar spinal decompression surgery: A retrospective cohort study

Background

Lumbar decompression is a commonly performed procedure for the operative management of several degenerative lumbar spinal pathologies. Although open approaches are considered the traditional method, endoscopic techniques represent a relatively novel, less-invasive option to achieve neural element decompression. Here within, we examine if the use of endoscopic techniques decreases the risk of post operative infections.

Methods

We performed a retrospective cohort analysis to directly compare patients who underwent either open or endoscopic lumbar decompression at a single institution. Rates of postoperative outcomes such as surgical site infection, hospital length of stay, estimated blood loss, and others were compared between the two treatment groups. A multivariate logistic regression model was constructed using patient comorbidities and procedural characteristics to identify the risk factors for surgical site infection.

Results

150 patients were identified as undergoing lumbar spine decompression surgeries that met inclusion criteria for the study, of whom 108 (72.0%) underwent open and 61 (28.0%) underwent endoscopic approaches. Unpaired analysis revealed positive associations between operative duration, estimated blood loss, drain placement rates. Multivariate logistic regression did not reveal an association between surgical approach (open versus endoscopic) and the development of surgical site infection.

Conclusions

Surgical site infections following endoscopic lumbar spine decompression are relatively uncommon, however, after adjusting for baseline differences between patient populations, surgical approach does not independently predict the development of postoperative infection.

The Influence of Spinous Process Union on Clinical Outcomes After Spinous Process Osteotomy for Lumbar Spinal Stenosis After 2 Years: A Secondary Analysis From the NORDSTEN-Study

BACKGROUND

Lumbar spinal stenosis is a prevalent and increasingly important cause of low back pain, leg pain, and walking impairment. Minimally invasive decompressive techniques such as spinous process (SP) osteotomy have become more common in recent years. The main aim of this study was to investigate the proportion of complete SP union and whether complete radiological healing after the osteotomy is associated with superior clinical outcome after 2 years.

METHODS

In this retrospective cohort study, 149 patients were included from the Spinal Stenosis Trial, a part of the NORwegian Degenerative spondylolisthesis and spinal STENosis study. Computed tomography imaging was performed 2 years postoperatively. The number of osteotomies and the number of SP unions were recorded. Patients were divided into groups based on the degree of union: nonunion, partial union, and complete union. Rate of success (>30% improvement in Oswestry Disability Index [ODI]) and mean change in ODI were the primary outcome measures. We compared the differences between baseline and follow-up between the Degree of Union groups.

RESULTS

The study included 102 of 149 eligible patients. Ten patients (9.8%) were classified as having nonunion, 15 (14.7%) as having partial union, and 77 (75.5%) as having complete union. Of the 155 osteotomies, there were 122 classified as union (77%). The success rate was 74%, with no influence of SP union. The mean change in the ODI was -20.1 (95% CI -37.0, 14.2) with no influence of SP union.

CONCLUSIONS

We found no influence of SP union, classified by computed tomography, on clinical outcome 2 years after SP osteotomy in patients with lumbar spinal stenosis.

CLINICAL RELEVANCE

Supplying useful information about SPO to assist surgeons in the choice of decompressive technique.

LEVEL OF EVIDENCE: 2

Assessing the benefits of digital twins in neurosurgery: a systematic review

Digital twins are virtual replicas of their physical counterparts, and can assist in delivering personalized surgical care. This PRISMA guideline-based systematic review evaluates current literature addressing the effectiveness and role of digital twins in many stages of neurosurgical management. The aim of this review is to provide a high-quality analysis of relevant, randomized controlled trials and observational studies addressing the neurosurgical applicability of a variety of digital twin technologies. Using pre-specified criteria, we evaluated 25 randomized controlled trials and observational studies on the applications of digital twins, including navigation, robotics, and image-guided neurosurgeries. All 25 studies compared these technologies against usual surgical approaches. Risk of bias analyses using the Cochrane risk of bias tool for randomized trials (Rob 2) found "low" risk of bias in the majority of studies (23/25). Overall, this systematic review shows that digital twin applications have the potential to be more effective than conventional neurosurgical approaches when applied to brain and spinal surgery. Moreover, the application of these novel technologies may also lead to fewer post-operative complications.

Machine Learning Predicts Decompression Levels for Lumbar Spinal Stenosis Using Canal Radiomic Features from Computed Tomography Myelography

BACKGROUND

The accurate preoperative identification of decompression levels is crucial for the success of surgery in patients with multi-level lumbar spinal stenosis (LSS). The objective of this study was to develop machine learning (ML) classifiers that can predict decompression levels using computed tomography myelography (CTM) data from LSS patients.

METHODS

A total of 1095 lumbar levels from 219 patients were included in this study. The bony spinal canal in CTM images was manually delineated, and radiomic features were extracted. The extracted data were randomly divided into training and testing datasets (8:2). Six feature selection methods combined with 12 ML algorithms were employed, resulting in a total of 72 ML classifiers. The main evaluation indicator for all classifiers was the area under the curve of the receiver operating characteristic (ROC-AUC), with the precision-recall AUC (PR-AUC) serving as the secondary indicator. The prediction outcome of ML classifiers was decompression level or not.

RESULTS

The embedding linear support vector (embeddingLSVC) was the optimal feature selection method. The feature importance analysis revealed the top 5 important features of the 15 radiomic predictors, which included 2 texture features, 2 first-order intensity features, and 1 shape feature. Except for shape features, these features might be eye-discernible but hardly quantified. The top two ML classifiers were embeddingLSVC combined with support vector machine (EmbeddingLSVC_SVM) and embeddingLSVC combined with gradient boosting (EmbeddingLSVC_GradientBoost). These classifiers achieved ROC-AUCs over 0.90 and PR-AUCs over 0.80 in independent testing among the 72 classifiers. Further comparisons indicated that EmbeddingLSVC_SVM appeared to be the optimal classifier, demonstrating superior discrimination ability, slight advantages in the Brier scores on the calibration curve, and Net benefits on the Decision Curve Analysis.

CONCLUSIONS

ML successfully extracted valuable and interpretable radiomic features from the spinal canal using CTM images, and accurately predicted decompression levels for LSS patients. The EmbeddingLSVC_SVM classifier has the potential to assist surgical decision making in clinical practice, as it showed high discrimination, advantageous calibration, and competitive utility in selecting decompression levels in LSS patients using canal radiomic features from CTM.

Acute disc herniation following surgical decompression of lumbar spinal stenosis: a retrospective comparison of mini-open and minimally invasive techniques

BACKGROUND

Disc herniation following decompression of lumbar spinal stenosis is a less familiar surgical complication. Previous studies suggested that open lumbar decompression techniques, associated with relative segmental instability especially in the presence of degenerated disc in older patients, are more likely to result in disc herniation compared to minimally invasive techniques. The current study compares the incidence of acute disc herniation following mini-open and minimally invasive decompression of lumbar spinal stenosis.

METHODS

This was a retrospective study reviewing 563 patients who underwent spinal decompression for symptomatic lumbar stenosis by mini-open bilateral partial laminectomy technique or minimally invasive laminotomy utilizing a tubular system. Demographic and clinical data were collected and compared between the groups.

RESULTS

Postoperative disc herniation rate was significantly lower in the minimally invasive group with 2 of 237 cases (0.8%) versus 19 of 326 cases (5.8%) in the mini-open group (p = 0.002). This finding was more noticeable following multi-level procedures with no case of postdecompression disc herniation in the minimally invasive group compared to 8 of 39 cases (20.5%) in the mini-open group (p = 0.003).

CONCLUSION

The incidence of postoperative disc herniation following spinal decompression for symptomatic lumbar stenosis was 5.8% following mini-open bilateral partial laminectomy compared to only 0.8% after minimally invasive laminotomy (p = 0.002). These findings highlight the more extensive nature of mini-open surgery associated with relative segmental instability that poses a greater risk for postoperative disc herniation.

The Call for Neuroendoscopy Cadaveric Workshops in Lower-Middle Income Countries

OBJECTIVE

This study aims to assess the impact of the workshops organized during Neuroendocon 23 on the perspective and confidence of neurosurgeons toward endoscopy in a lower-middle income country.

METHODS

Neuroendocon 23 had cranial and spinal endoscopy cadaveric workshops with 30 delegates each. A pre and postworkshop survey was disseminated among the delegates, and statistical analysis was performed with SPSS (version 26) using P < 0.05.

RESULTS

A total of 24 delegates (40%) consented to participate in the study, with only 1 female respondent (4.17%). After the cranial endoscopy workshop, there was an increase in the level of confidence of delegates in cranial endoscopic approaches (P < 0.001). Similarly, after the spine endoscopy workshop, the respondents had increased confidence in managing spine conditions with the endoscopic approach (P = 0.040), to the extent that they preferred the endoscopic over the microsurgical technique (P < 0.001). All respondents (n = 24, 100%) believed that endoscopy should be promoted in lower-middle income countries and integrated into residency curricula.

CONCLUSIONS

Cranial and spinal endoscopy cadaveric workshops could be the first step in stimulating the interest of neurosurgeons in endoscopy.

Interventional Therapy and Surgical Management of Lumbar Disc Herniation in Spine Surgery: A Narrative Review

Significant advancements in lumbar disc herniation (LDH) management have been made in interventional pain therapy, operative therapy, peri-operative management, and cost analysis of various procedures. The present review aims to provide a concise narrative of all these topics, current trends, and possible future directions in the management of LDH. Interventional pain management using intradiscal injections often serves as a minimally invasive non-surgical approach. Surgical modalities vary, including traditional open laminectomy, microdiscectomy, endoscopic discectomy, tubular discectomy, percutaneous laser disc decompression, and transforaminal foraminotomy. Prevention of infections during surgery is paramount and is often done via a single-dose preoperative antibiotic prophylaxis. Recurrence of LDH post-surgery is commonly observed and thus mitigative strategies for prevention have been proposed including the use of annular closure devices. Finally, all treatments are well-associated with clear as well as hidden costs to the health system and society as described by billing codes and loss of patients' quality-adjusted life-years. Our summary of recent literature regarding LDH may allow physicians to employ up-to-date evidence-based practice in clinical settings and can help drive future advancements in LDH management. Future longitudinal and comprehensive studies elucidating how each type of treatments fare against different types of herniations are warranted.

Improvement in predominant back pain following minimally invasive decompression for spinal stenosis

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.

Use of a High-Fidelity Training Simulator for Minimally Invasive Lumbar Decompression Increases Working Knowledge and Technical Skills Among Orthopedic and Neurosurgical Trainees

STUDY DESIGN

Prospective comparative study.

OBJECTIVE

To quantify the educational benefit to surgical trainees of using a high-fidelity simulator to perform minimally invasive (MIS) unilateral laminotomy for bilateral decompression (ULBD) for lumbar stenosis.

METHODS

Twelve orthopedic and neurologic surgery residents performed three MIS ULBD procedures over 2 weeks on a simulator guided by established AO Spine metrics. Video recording of each surgery was rated by three blinded, independent experts using a global rating scale. The learning curve was evaluated with attention to technical skills, skipped steps, occurrence of errors, and timing. A knowledge gap analysis evaluating participants' current vs desired ability was performed after each trial.

RESULTS

From trial 1 to 3, there was a decrease in average procedural time by 31.7 minutes. The cumulative number of skipped steps and surgical errors decreased from 25 to 6 and 24 to 6, respectively. Overall surgical proficiency improved as indicated by video rating of efficiency and smoothness of surgical maneuvers, most notably with knowledge and handling of instruments. The greatest changes were noted in junior rather than senior residents. Average knowledge gap analysis significantly decreased by 30% from the first to last trial (P = .001), signifying trainees performed closer to their desired technical goal.

CONCLUSION

Procedural metrics for minimally invasive ULBD in combination with a realistic surgical simulator can be used to improve the skills and confidence of trainees. Surgical simulation may offer an important educational complement to traditional methods of skill acquisition and should be explored further with other MIS techniques.

Augmented Reality in Minimally Invasive Spinal Surgery: A Narrative Review of Available Technology

INTRODUCTION

Spine surgery has undergone significant changes in approach and technique. With the adoption of intraoperative navigation, minimally invasive spinal surgery (MISS) has arguably become the gold standard. Augmented reality (AR) has now emerged as a front-runner in anatomical visualization and narrower operative corridors. In effect, AR is poised to revolutionize surgical training and operative outcomes. Our study examines the current literature on AR-assisted MISS, synthesizes findings, and creates a narrative highlighting the history and future of AR in spine surgery.

MATERIAL AND METHODS

Relevant literature was gathered using the PubMed (Medline) database from 1975 to 2023. Pedicle screw placement models were the primary intervention in AR. These were compared to the outcomes of traditional MISS RESULTS: We found that AR devices on the market show promising clinical outcomes in preoperative training and intraoperative use. Three prominent systems were as follows: XVision, HoloLens, and ImmersiveTouch. In the studies, surgeons, residents, and medical students had opportunities to operate AR systems, showcasing their educational potential across each phase of learning. Specifically, one facet described training with cadaver models to gauge accuracy in pedicle screw placement. AR-MISS exceeded free-hand methods without unique complications or contraindications.

CONCLUSIONS

While still in its infancy, AR has already proven beneficial for educational training and intraoperative MISS applications. We believe that with continued research and advancement of this technology, AR is poised to become a dominant player within the fundamentals of surgical education and MISS operative technique.

Is the presence of foraminal stenosis associated with outcome in lumbar spinal stenosis patients treated with posterior microsurgical decompression

BACKGROUND

We aim to investigate associations between preoperative radiological findings of lumbar foraminal stenosis with clinical outcomes after posterior microsurgical decompression in patients with predominantly central lumbar spinal stenosis (LSS).

METHODS

The study was an additional analysis in the NORDSTEN Spinal Stenosis Trial. In total, 230 men and 207 women (mean age 66.8 (SD 8.3)) were included. All patients underwent an MRI including T1- and T2-weighted sequences. Grade of foraminal stenosis was dichotomized into none to moderate (0-1) and severe (2-3) category using Lee's classification system. The Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and numeric rating scale (NRS) for back and leg pain were collected at baseline and at 2-year follow-up. Primary outcome was a reduction of 30% or more on the ODI score. Secondary outcomes included the mean improvement on the ODI, ZCQ, and NRS scores. We performed multivariable regression analyses with the radiological variates foraminal stenosis, Pfirrmann grade, Schizas score, dural sac cross-sectional area, and the possible plausible confounders: patients' gender, age, smoking status, and BMI.

RESULTS

The cohort of 437 patients presented a high degree of degenerative changes at baseline. Of 414 patients with adequate imaging of potential foraminal stenosis, 402 were labeled in the none to moderate category and 12 in the severe category. Of the patients with none to moderate foraminal stenosis, 71% achieved at least 30% improvement in ODI. Among the patients with severe foraminal stenosis, 36% achieved at least 30% improvement in ODI. A significant association between severe foraminal stenosis and less chance of reaching the target of 30% improvement in the ODI score after surgery was detected: OR 0.22 (95% CI 0.06, 0.83), p=0.03. When investigating outcome as continuous variables, a similar association between severe foraminal stenosis and less improved ODI with a mean difference of 9.28 points (95%CI 0.47, 18.09; p=0.04) was found. Significant association between severe foraminal stenosis and less improved NRS pain in the lumbar region was also detected with a mean difference of 1.89 (95% CI 0.30, 3.49; p=0.02). No significant association was suggested between severe foraminal stenosis and ZCQ or NRS leg pain.

CONCLUSION

In patients operated with posterior microsurgical decompression for LSS, a preoperative severe lumbar foraminal stenosis was associated with higher proportion of patients with less than 30% improvement in ODI.

TRIAL REGISTRATION

The study is registered at ClinicalTrials.gov (22.11.2013) under the identifier NCT02007083.

Comparative Analysis of Non-Full and Full Endoscopic Spine Technique via Interlaminar Approach for the Treatment of Degenerative Lumbar Spinal Stenosis: A Retrospective, Single Institute, Propensity Score-Matched Study

STUDY DESIGN

Retrospective study.

OBJECTIVE

To compare the clinical efficacy of posterior lumbar laminectomy decompression under full endoscopic technique (Endo-LOVE) and percutaneous endoscopic medial foraminal decompression (PE-MFD) in the treatment of degenerative lumbar spinal stenosis (DLSS).

METHODS

Between April 2017 and April 2018, 96 patients with DLSS underwent Endo-LOVE or PE-MFD, including 58 with Endo-LOVE and 38 with PE-MFD. After propensity score matching (PSM), patient characteristics, operation time, intraoperative fluoroscopy times, postoperative bedridden time, hospital stay and postoperative complications were recorded and compared. The clinical efficacy was evaluated according to Oswestry disability index (ODI), visual analogue scale (VAS), lumbar disease JOA and modified MacNab criteria.

RESULTS

A total of 96 patients with DLSS were included in the study. After PSM, the 2 groups were comparable in patient demographic and baseline characteristics. The operation time and intraoperative fluoroscopy times in PE-MFD group were significantly more than those in Endo-LOVE group (P < .05). The operation time in PE-MFD group was significantly less than that in Endo-LOVE group (P < .05).The intraoperative fluoroscopy times in PE-MFD group were significantly more than that in Endo-LOVE group (P < .05). The ODI, VAS and lumbar disease JOA in the 2 groups were significantly improved comparing with those before operation (P < .05). According to the modified MacNab criteria, the excellent and good rates of the 2 groups were 93.5% in Endo-LOVE group and 87.1% in PE-MFD group (P > .05).

CONCLUSION

Endo-LOVE and PE-MFD technique can both effectively treat DLSS, and the short-term follow-up results are positive. Endo-LOVE technique has the advantages of fast puncture positioning, less radiation exposure and wider indications. However, PE-MFD needs more radiation exposure and has the possibility of incomplete decompression for complex multiplanar spinal stenosis.

Surgery for Metastatic Spinal Disease in Octogenarians and Above: Analysis of 78 Patients

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

Octogenarians living with spinal metastases are a challenging population to treat. Our objective was to identify the rate, types, management, and predictors of complications and survival in octogenarians following surgery for spinal metastases.

METHODS

A retrospective review of a prospectively collected cohort of patients aged 80 years or older who underwent surgery for metastatic spinal tumor treatment between 2008 and 2019 were included. Demographic, intraoperative, complications, and postoperative follow-up data was collected. Cox proportional hazards regression and logistic regression were used to associate variables with overall survival and postoperative complications, respectively.

RESULTS

78 patients (mean 83.6 years) met inclusion criteria. Average operative time and blood loss were 157 minutes and 615 mL, respectively. The median length of stay was 7 days. The overall complication rate was 31% (N = 24), with 21% considered major and 7% considered life-threatening or fatal. Blood loss was significantly associated with postoperative complications (OR = 1.002; P = 0.02) and mortality (HR = 1.0007; P = 0.04). Significant associations of increased risk of death were also noted with surgeries with decompression, and cervical/cervicothoracic index level of disease. For deceased patients, median time to death was 4.5 months. For living patients, median follow-up was 14.5 months. The Kaplan-Meier based median overall survival for the cohort was 11.6 months (95% CI: 6.2-19.1).

CONCLUSIONS

In octogenarians undergoing surgery with instrumentation for spinal metastases, the median overall survival is 11.6 months. There is an increased complication rate, but only 7% are life-threatening or fatal. Patients are at increased risk for complications and mortality particularly when performing decompression with stabilization, with increasing intraoperative blood loss, and with cervical/cervicothoracic tumors.

Technological Advances in Spine Surgery: Navigation, Robotics, and Augmented Reality

Accurate screw placement is critical to avoid vascular or neurologic complications during spine surgery and to maximize fixation for fusion and deformity correction. Computer-assisted navigation, robotic-guided spine surgery, and augmented reality surgical navigation are currently available technologies that have been developed to improve screw placement accuracy. The advent of multiple generations of new technologies within the past 3 decades has presented surgeons with a diverse array of choices when it comes to pedicle screw placement. Considerations for patient safety and optimal outcomes must be paramount when selecting a technology.

Return to work after surgery for degenerative cervical myelopathy: a nationwide registry-based observational study

BACKGROUND

Few studies of high quality exist on return to work (RTW) rate after surgery for degenerative cervical myelopathy (DCM). This study aims to examine the RTW rate in patients undergoing surgery for DCM.

METHODS

Nationwide prospectively collected data were obtained from the Norwegian Registry for Spine Surgery and the Norwegian Labour and Welfare Administration. The primary outcome was return to work, defined as being at work at a given time postoperatively without any medical income-compensation benefits. Secondary endpoints included the neck disability index (NDI) and quality of life measured by EuroQol-5D (EQ-5D).

RESULTS

Among 439 patients operated for DCM between 2012 and 2018, 20% of the patients received a medical income-compensation benefit one year before surgery. This number increased steadily towards the operation at which timepoint 100% received benefits. By 12 months after surgery, 65% had returned to work. By 36 months, 75% had returned to work. Patients that returned to work were more likely to be non-smokers and to have a college education. They had less comorbidity, more were without benefit 1-year pre-surgery, and significantly more patients were employed at operation date. Average days of sick leave in the year before surgery were significantly less in the RTW group, and they had a significantly lower baseline NDI and EQ-5D All PROMs reached statistical significance at 12 months, in favor of the group that achieved RTW.

CONCLUSION

At 12 months following surgery, 65% had returned to work. At the end of the 36-month follow-up period, 75% had returned to work, 5% less than the working percentage in the beginning of the follow-up period. This study demonstrates that a large percentage of patients return to work after surgical treatment for DCM.

Return to Work After Surgery for Cervical Radiculopathy: A Nationwide Registry-based Observational Study

STUDY DESIGN

An observational multicenter study.

SUMMARY OF BACKGROUND DATA

Return to work (RTW) is increasingly used to assess the standard, benefit, and quality of health care.

OBJECTIVE

The aim of this study was to evaluate sick leave patterns among patients undergoing surgery for cervical radiculopathy and identify predictors of successful RTW using two nationwide databases.

MATERIALS AND METHODS

Data from the Norwegian Registry for Spine Surgery (NORspine) and the Norwegian Labour and Welfare Administration were linked on an individual level. We included patients between 18 and 60 years of age registered in NORspine from June 2012 through December 2019 that were temporarily out of the labor force for medical reasons at the time of surgery. We assessed types and grades of sickness benefits before and after surgery and conducted logistic regression analyses.

RESULTS

Among 3387 patients included in the study, 851 (25.1%) received temporary benefits one year before surgery. The proportion of recipients increased steadily towards surgery. Postoperatively the medical benefit payment decreased rapidly, and half of the patients had already returned to work by four months. The rate of RTW reached a plateau at one year. By the end of the third year, 2429 patients (71.7%) had returned to work. The number of sick days, categorized as 90 or less, during the year before surgery had the most powerful association with RTW at two years (odds ratio: 4.54, 95% CI: 3.42-6.03, P <0.001). Improvement in neck-related disability was the second strongest predictor (odds ratio: 2.17, 95% CI: 1.69-2.78, P <0.001).

CONCLUSION

RTW after cervical radiculopathy surgery occurs primarily during the first year. The strongest predictor of RTW was fewer sick days before surgery. The clinical improvement after surgery had a lesser impact.

LEVEL OF EVIDENCE

2.

Management of lumbar spinal stenosis: a systematic review and meta-analysis of rehabilitation, surgical, injection, and medication interventions

BACKGROUND

Lumbar spinal stenosis (LSS) has a substantial impact on mobility, autonomy, and quality of life. Previous reviews have demonstrated inconsistent results and/or have not delineated between specific nonsurgical interventions.

OBJECTIVE

The purpose of this systematic review is to assess the effectiveness of interventions in the management of LSS.

METHODS

Eligible studies were randomized controlled trials (RCTs) or prospective studies, included patients with LSS, assessed the effectiveness of any interventions (rehabilitation, surgical, injection, medication), included at least two intervention groups, and included at least one measure of pain, disability, ambulation assessment, or LSS-specific symptoms. Eighty-five articles met inclusion criteria. Meta-analyses were conducted across outcomes. Effect sizes were calculated using Hedge's g and reported descriptively. Formal grading of evidence was conducted.

RESULTS

Meta-analysis comparing rehabilitation to no treatment/placebo demonstrated significant effects on pain favoring rehabilitation (mean difference, MD -1.63; 95% CI: -2.68, -0.57; I² = 71%; p = .002). All other comparisons to no treatment/placebo revealed nonsignificant findings. The level of evidence ranged from very low to high for rehabilitation and medication versus no treatment/placebo for pain, disability, ambulation ability, and LSS symptoms.

CONCLUSIONS

Although the findings of this review are inconclusive regarding superiority of interventions, this accentuates the value of multimodal patient-centered care in the management of patients with LSS.

Predictors for failure after surgery for lumbar spinal stenosis: a prospective observational study

BACKGROUND/CONTEXT

Some patients do not improve after surgery for lumbar spinal stenosis (LSS), and surgical treatment implies a risk for complications and deterioration. Patient selection is of paramount importance to improve the overall clinical results and identifying predictive factors for failure is central in this work.

PURPOSE

We aimed to explore predictive factors for failure and worsening after surgery for LSS.

STUDY DESIGN /SETTING

Retrospective observational study on prospectively collected data from a national spine registry with a 12-month follow-up.

PATIENT SAMPLE

We analyzed 11,873 patients operated for LSS between 2007 and 2017 in Norway, included in the Norwegian registry for spine surgery (NORspine). Twelve months after surgery, 8919 (75.1%) had responded.

OUTCOME MEASURES

Oswestry Disability Index (ODI) 12 months after surgery.

METHODS

Predictors were assessed with uni- and multivariate logistic regression, using backward conditional stepwise selection and a significance level of 0.01. Failure (ODI>31) and worsening (ODI>39) were used as dependent variables.

RESULTS

Mean (95%CI) age was 66.6 (66.4-66.9) years, and 52.1% were females. The mean (95%CI) preoperative ODI score was 39.8 (39.4-40.1). All patients had decompression, and 1494 (12.6%) had an additional fusion procedure. Twelve months after surgery, the mean (95%CI) ODI score was 23.9 (23.5-24.2), and 2950 patients (33.2%) were classified as failures and 1921 (21.6%) as worse. The strongest predictors for failure were duration of back pain > 12 months (OR [95%CI]=2.24 [1.93-2.60]; p<.001), former spinal surgery (OR [95%CI]=2.21 [1.94-2.52]; p<.001) and age>70 years (OR (95%CI)=1.97 (1.69-2.30); p<.001). Socioeconomic variables increased the odds of failure (ORs between 1.36 and 1.62). The strongest predictors for worsening were former spinal surgery (OR [95%CI]=2.04 [1.77-2.36]; p<.001), duration of back pain >12 months (OR [95%CI]=1.83 [1.45-2.32]; p<.001) and age >70 years (OR [95%CI]=1.79 [1.49-2.14]; p<.001). Socioeconomic variables increased the odds of worsening (ORs between 1.33-1.67).

CONCLUSIONS

After surgery for LSS, 33% of the patients reported failure, and 22% reported worsening as assessed by ODI. Preoperative duration of back pain for longer than 12 months, former spinal surgery, and age above 70 years were the strongest predictors for increased odds of failure and worsening after surgery.

A Comparative Analysis of Bi-Portal Endoscopic Spine Surgery and Unilateral Laminotomy for Bilateral Decompression in Multilevel Lumbar Stenosis Patients

The clinical and radiological results before and after surgery were compared and analyzed for patients with multilevel lumbar stenosis who underwent bi-portal endoscopic spine surgery (BESS) and microscopic unilateral laminotomy for bilateral decompression (ULBD). We retrospectively identified 47 and 49 patients who underwent BESS and microscopic ULBD, respectively, who were diagnosed with multi-level lumbar stenosis. Clinical outcomes were evaluated using the visual analog scale score for both back and leg pain, and medication (pregabalin) use and Oswestry Disability Index (ODI) scores for overall treatment outcomes were used pre-operatively and at the final follow-up. Radiological outcomes were evaluated as the percentage of dura expansion volume, and percentage preservation of both facets and both lateral recess angles. The follow-up period of patients was about 17.04 months in the BESS group and about 16.90 months in the microscopic ULBD group. The back and leg visual analog scale (VAS) scores and average pregabalin use decreased more significantly in the BESS group than in the microscopic ULBD group (each p-value 0.0443, <0.001, 0.0378). All radiological outcomes were significantly higher in the BESS group than in the ULBD group. The change in ODI in two-level spinal stenosis showed a significantly higher value in the BESS group compared to the microscopic ULBD group (p-value 0.0335). Multilevel decompression with the BESS technique in multiple spinal stenosis is an adequate technique as it shows better clinical and radiological results than microscopic ULBD during a short-term follow-up period.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication

BACKGROUND

The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine.

METHODS

The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members.

RESULTS

Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided.

CONCLUSIONS

The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

Full-endoscopic versus microscopic unilateral laminotomy for bilateral decompression of lumbar spinal stenosis at L4-L5: comparative study

PURPOSE

Full-endoscopic spine surgery for degenerative lumbar diseases is growing in popularity and has shown favourable outcomes. Lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has been used to treat lumbar spinal stenosis (LSS). However, studies comparing LE-ULBD to microscopic ULBD are lacking. This study compared the clinical efficacy and radiological outcomes between the LE-ULBD and microscopic ULBD.

METHODS

The study retrospectively enrolled patients undergoing either LE-ULBD or microscopic ULBD for spinal stenosis at the L4-L5 level. The demographic data, operative details, radiological images, clinical outcomes, and complications of patients from the two groups were compared through matched-pairs analysis. The minimum follow-up duration was 24 months.

RESULTS

There were 93 patients undergoing either LE-ULBD (n = 42) or microscopic ULBD (n = 51). The patient demographics were similar between the two groups. The LE-ULBD group had significantly less estimated blood loss, less analgesic use, and shorter hospitalization duration (P < .05). The endoscopic group had a significantly lower visual analog scale for back pain at all follow-up intervals compared with the microscopic group (P < .05). There were no significant differences in leg pain or Oswestry Disability Index. The cross-section area of the spinal canal was significantly wider after microscopic ULBD. There were no significant differences in post-operative degenerative changes in disc height, translational motion, or facet preservation rate.

CONCLUSIONS

LE-ULBD is comparable in clinical and radiological outcomes with enhanced recovery for single-level LSS. The endoscopic approach might further minimize tissue injury and enhance post-operative recovery.

Microscopic Unilateral Approach for Bilateral Decompression of Lumbar Spinal Stenosis

BACKGROUND

This is a study based on single-surgeon data on spinal stenosis surgery via microscopic approach. The aim is to evaluate the effectiveness of the unilateral approach to bilateral decompression and the usage of Taylor retractors and brain spatula in patients with spinal stenosis.

METHODS

This is a retrospective study on bilateral decompression for lumbar spinal stenosis using a microscopic unilateral approach by a single surgeon, between April 2015 and March 2018. In total, 50 patients were operated due to single level lumbar spinal stenosis. All patients were evaluated by preoperative and postoperative plain radiographs and magnetic resonance (MR) images. Walking distance (WD), visual analog scale (VAS) for pain and Odom's criteria were evaluated for follow-up.

RESULTS

One level of the lumbar spine was surgically decompressed in all patients. The median age of patients was 64.6 (51- 82). Of the patients, 72% (36) were women, and 28% (14) were men. Most patients had refractory low back pain (96%) after conservative treatment. The stenotic levels of the cases were as follows: L3-4, 23(46%); L4-5, 24(48%); and L5-S1, 3 (6%). VAS scores decreased in all patients after surgery. According to Odom's criteria, an excellent or good score was found in 43 patients at the 12th follow-up examination. WDs increased up to 1000 meters for 41 patients.

CONCLUSION

The microscopic unilateral approach to bilateral decompression is an effective method for decompression in spinal stenosis. Via this approach, surgical trauma is reduced and surgically induced instability is avoided as much as possible.

Effect of Spinal Cord Burst Stimulation vs Placebo Stimulation on Disability in Patients With Chronic Radicular Pain After Lumbar Spine Surgery: A Randomized Clinical Trial

IMPORTANCE

The use of spinal cord stimulation for chronic pain after lumbar spine surgery is increasing, yet rigorous evidence of its efficacy is lacking.

OBJECTIVE

To investigate the efficacy of spinal cord burst stimulation, which involves the placement of an implantable pulse generator connected to electrodes with leads that travel into the epidural space posterior to the spinal cord dorsal columns, in patients with chronic radiculopathy after surgery for degenerative lumbar spine disorders.

DESIGN, SETTING, AND PARTICIPANTS

This placebo-controlled, crossover, randomized clinical trial in 50 patients was conducted at St Olavs University Hospital in Norway, with study enrollment from September 5, 2018, through April 28, 2021. The date of final follow-up was May 20, 2022.

INTERVENTIONS

Patients underwent two 3-month periods with spinal cord burst stimulation and two 3-month periods with placebo stimulation in a randomized order. Burst stimulation consisted of closely spaced, high-frequency electrical stimuli delivered to the spinal cord. The stimulus consisted of a 40-Hz burst mode of constant-current stimuli with 4 spikes per burst and an amplitude corresponding to 50% to 70% of the paresthesia perception threshold.

MAIN OUTCOMES AND MEASURES

The primary outcome was difference in change from baseline in the self-reported Oswestry Disability Index (ODI; range, 0 points [no disability] to 100 points [maximum disability]; the minimal clinically important difference was 10 points) score between periods with burst stimulation and placebo stimulation. The secondary outcomes were leg and back pain, quality of life, physical activity levels, and adverse events.

RESULTS

Among 50 patients who were randomized (mean age, 52.2 [SD, 9.9] years; 27 [54%] were women), 47 (94%) had at least 1 follow-up ODI score and 42 (84%) completed all stimulation randomization periods and ODI measurements. The mean ODI score at baseline was 44.7 points and the mean changes in ODI score were -10.6 points for the burst stimulation periods and -9.3 points for the placebo stimulation periods, resulting in a mean between-group difference of -1.3 points (95% CI, -3.9 to 1.3 points; P = .32). None of the prespecified secondary outcomes showed a significant difference. Nine patients (18%) experienced adverse events, including 4 (8%) who required surgical revision of the implanted system.

CONCLUSIONS AND RELEVANCE

Among patients with chronic radicular pain after lumbar spine surgery, spinal cord burst stimulation, compared with placebo stimulation, after placement of a spinal cord stimulator resulted in no significant difference in the change from baseline in self-reported back pain-related disability.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03546738.

Clinical Application of Large Channel Endoscopic Systems with Full Endoscopic Visualization Technique in Lumbar Central Spinal Stenosis: A Retrospective Cohort Study

INTRODUCTION

Recently, large channel endoscopic systems and full endoscopic visualization technique have been used to perform unilateral laminotomy for bilateral decompression (ULBD) treatment for lumbar central spinal stenosis (LCSS). However, various endoscopic systems possess different design parameters, which may affect the technical points and treatment outcomes. The object of this retrospective study was to compare the efficiency, safety, and effectiveness of ULBD under the iLESSYS Delta system versus the Endo-Surgi Plus system.

METHODS

In the period from October 2020 to April 2021, ULBD was performed using the iLESSYS Delta system or Endo-Surgi Plus system to treat LCSS. Patients were classified into two groups based on the endoscopy system employed. Patient demographics, perioperative indexes, complications, and imaging characteristics were reviewed. Clinical outcomes were quantified using back and leg visual analog scale (VAS) scores and Oswestry Disability Index (ODI) at the time points of follow-up.

RESULTS

Thirty-two patients were assigned to the iLESSYS Delta system group and 37 to the Endo-Surgi Plus system group. In the comparison between the two groups, the Endo-Surgi Plus system possessed a shorter incision length and operation time (p < 0.005), and no statistical differences in other aspects were observed. The dural sacs of both groups were significantly expanded postoperatively compared to preoperatively (p < 0.001). Both groups experienced improvements in VAS and ODI scores at all time points (p < 0.001) and equally low frequency of complications.

CONCLUSIONS

Current research suggests that both the Endo-Surgi Plus system and iLESSYS Delta system achieved favorable high safety and clinical outcomes in ULBD for treatment of LCSS. The use of a fully visualized trephine may have increased the efficiency of the Endo-Surgi Plus system. Moreover, the Endo-Surgi Plus system may be associated with a wider decompression range and indications.

Surgery for degenerative cervical myelopathy in the elderly: a nationwide registry-based observational study with patient-reported outcomes

BACKGROUND

The aim of this study was to investigate whether clinical outcomes in patients aged ≥ 70 undergoing decompressive surgery for degenerative cervical myelopathy (DCM) differ from those of younger patients (50-70 years) at 1 year.

METHODS

Data were obtained from the Norwegian Registry for Spine Surgery (NORspine). Among 651 patients included, 177 (27.2%) were ≥ 70 years old. The primary outcome was change in the Neck Disability Index (NDI). Secondary outcomes were changes in the European Myelopathy Score (EMS), quality of life (EuroQoL EQ-5D), numeric rating scales (NRS) for headache, neck pain, and arm pain, and complications.

RESULTS

Significant improvements in all patient-reported outcomes (PROMs) were detected for both age cohorts at 1 year. For the two age cohorts combined, there was a statistically significant improvement in the NDI score (mean 9.2, 95% CI 7.7 to 10.6, P < 0.001). There were no differences between age cohorts in mean change of NDI (- 8.9 vs. - 10.1, P = 0.48), EQ-5D (0.13 vs. 0.17, P = 0.37), or NRS pain scores, but elderly patients experienced a larger improvement in EMS (0.7 vs. 1.3, P = 0.02). A total of 74 patients (15.6%) in the younger cohort and 43 patients (24.3%) in the older cohort experienced complications or adverse effects within 3 months of surgery, mainly urinary and respiratory tract infections.

CONCLUSION

Surgery for DCM was associated with significant improvement across a wide range of PROMs for both younger and elderly patients. Surgery for DCM should not be denied based on age alone.

Systematic Review of Cost-Effectiveness Analyses Comparing Open and Minimally Invasive Lumbar Spinal Surgery

BACKGROUND

Minimally invasive surgery (MIS) has benefits over open surgery for lumbar decompression and/or fusion. Published literature on its cost-effectiveness vs open techniques is mixed.

OBJECTIVE

Systematically review the cost-effectiveness of minimally invasive vs open lumbar spinal surgical decompression, fusion, or discectomy using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

METHODS

A systematic electronic search of databases (MEDLINE, Embase, and Cochrane Library) and a manual search from the cost-effectiveness analysis (CEA) database and National Health Service economic evaluation database was conducted. Studies that included adult populations undergoing surgery for degenerative changes in the lumbar spine (stenosis, radiculopathy, and spondylolisthesis) and reported outcomes of costing analysis, CEA, or incremental cost-effectiveness ratio were included.

RESULTS

A total of 17 studies were included. Three studies assessed outcomes of MIS vs open discectomy. All 3 reported statistically significant lower total costs in the MIS, compared with the open group, with similar reported gains in quality-adjusted life years (QALYs). Two studies reported cost differences in MIS vs open laminectomy, with significantly lower total costs attributed to the MIS group. Twelve studies reported findings on the relative direct costs of MIS vs open lumbar fusion. Among those, 3 of the 4 studies comparing single-level MIS-transforaminal lumbar interbody fusion (TLIF) and open TLIF reported lower total costs associated with MIS procedures. Six studies reported cost evaluation of single- and 2-level TLIF procedures. Lower total costs were found in the MIS group compared with the open fusion group in all studies except for the subgroup analysis of 2-level fusions in a single study. Three of these 6 studies reported cost-effectiveness (cost/QALY). MIS fusion was found to be more cost-effective than open fusion in all 3 studies.

CONCLUSION

The studies reviewed were of poor to moderate methodological quality. Generally, studies reported a reduced cost associated with MIS vs open surgery and suggested better cost-effectiveness, particularly in MIS vs open single- and 2-level TLIF procedure. Most studies had a high risk of bias. Therefore, this review was unable to conclusively recommend MIS over open surgery from a cost-effectiveness perspective.

CLINICAL RELEVANCE

The incidence of spinal decompressive and fusion surgey and financial constraints on healthcare services continue to increase. This study aims to identify the cost and clinical effectiveness of common approaches to spinal surgery.

LEVEL OF EVIDENCE

3a.

Challenges Hindering Widespread Adoption of Minimally Invasive Spinal Surgery

Minimally invasive spinal surgery (MISS) techniques offer several beneficial prospects and are being increasingly requested by patients. However, these techniques have not been uniformly adopted by spinal surgeons, and they remain controversial among some. Several barriers have prevented widespread adoption of MISS. These include concerns regarding high start-up costs, limited evidence base, and lack of surgeon training. In addition, the unique approaches involved in MISS expose spinal surgeons to unfamiliar anatomy. Further, while MISS can address a growing spectrum of spinal pathology, some conditions, as well as complications encountered during MISS procedures, require open surgery. This requires surgeons to not only acquire the new and specialized MISS skillset but also maintain their ability to perform open surgery. These factors present challenges common to developing and innovative surgical techniques. Here, we review the barriers preventing wider adoption of MISS and present a framework to promote the safe and effective growth of MISS.

The Future of Minimally Invasive Spinal Surgery

Strong forces are pushing minimally invasive spinal surgery (MISS) to the forefront of spine care. Less-invasive surgical techniques have been enabled by a variety of technical advances. Despite the promise of MISS, however, several factors, including few training opportunities, perception of a steep learning curve, and high upfront costs, have limited the adoption of these techniques. The "6 T's" is a framework highlighting key factors that must be accounted for to ensure safe and effective MISS as techniques continually evolve. Further, technological advancement in endoscopy, robotics, and augmented/virtual reality is enhancing minimally invasive surgeries to make them even less invasive and safer for patients. The evolution of these new techniques and technologies is driving the future of MISS.

Minimally Invasive Spine Surgery: An Overview

Spinal surgery is undergoing a major transformation toward a minimally invasive paradigm. This shift is being driven by multiple factors, including the need to address spinal problems in an older and sicker population, as well as changes in patient preferences and reimbursement patterns. Increasingly, minimally invasive surgical techniques are being used in place of traditional open approaches due to significant advancements and implementation of intraoperative imaging and navigation technologies. However, in some patients, due to specific anatomic or pathologic factors, minimally invasive techniques are not always possible. Numerous algorithms have been described, and additional efforts are underway to better optimize patient selection for minimally invasive spinal surgery (MISS) procedures in order to achieve optimal outcomes. Numerous unique MISS approaches and techniques have been described, and several have become fundamental. Investigators are evaluating combinations of MISS techniques to further enhance the surgical workflow, patient safety, and efficiency.

Best Practices for Minimally Invasive Lumbar Spinal Stenosis Treatment 2.0 (MIST): Consensus Guidance from the American Society of Pain and Neuroscience (ASPN)

Introduction

Methods

Results

Discussion

Conclusion

Persistent Use of Prescription Opioids Following Lumbar Spine Surgery: Observational Study with Prospectively Collected Data From Two Norwegian Nationwide Registries

STUDY DESIGN

Prospective pharmacoepidemiological study.

OBJECTIVE

To investigate the use of prescription opioids 2 years following degenerative lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

There are limited data providing details to evaluate patterns of opioid use. The number of patients is often limited and data on opioid use following some of the most common surgical procedures are lacking.

METHODS

Data from the Norwegian Registry for Spine Surgery and the Norwegian Prescription Database were linked on an individual level. The primary outcome measure was persistent opioid use the second year after surgery. Functional disabilitywas measured with the Oswestry disability index (ODI). Study participants were operated between 2007 and 2017.

RESULTS

Among 32,886 study participants, 2754 (8.4%) met criteria for persistent opioid use the second year after surgery. Among persistent opioid users in the second year after surgery, 64% met the criteria for persistent opioid use the year preceding surgery. Persistent opioid use the year preceding surgery (odds ratio [OR] 31.10, 95% confidence interval [CI] 26.9-36.0, P  = 0.001), use of high doses of benzodiazepines (OR 1.62, 95% CI 1.30-2.04, P  = 0.001), and use of high doses of z-hypnotics (OR 1.90, 95% CI 1.58-2.22, P  = 0.001) the year before surgery were associated with increased risk of persistent opioid use the second year after surgery. A higher ODI score at 1 year was observed in persistent opioid users compared with non-persistent users (41.5 vs. 18.8 points) and there was a significant difference in ODI change (-13.7 points). Patients with persistent opioid use in the year preceding surgery were less likely to achieve a minimal clinically important ODI change at 1 year compared with non-persistent users (37.7% vs. 52.6%, P  = 0.001).

CONCLUSION

Patients with or at risk of developing persistent opioid should be identified and provided counseling and support to taper off opioid treatment.Level of Evidence: 2.

No Benefit with Preservation of Midline Structures in Decompression for Lumbar Spinal Stenosis: Results From the National Swedish Spine Registry 2-Year Post-Op

STUDY DESIGN

Observational cohort study.

OBJECTIVE

The aim of this study was to investigate whether preservation of the midline structures is associated with a better clinical outcome compared to classic central decompression for lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

The classic surgical procedure for LSS is a central, facet joint sparing decompressive laminectomy (LE). Alternative approaches have been developed to preserve the midline structures. The effect of the alternative techniques compared to LE remains unclear.

METHODS

All patients >50 years of age who underwent decompression surgery for LSS without concomitant fusion in the National Swedish Spine Registry (Swespine) from December 31, 2015 until October 6, 2017 were included in this study based on surgeon-reported data and patient questionnaires before and 2 years postoperatively. Propensity score matching was used to compare decompression with preservation of midline structures with patients who underwent LE. The primary outcome was the Oswestry Disability Index (ODI) and secondary outcomes were the Numeric Rating Scale (NRS) for leg and back pain, EuroQol-5 Dimensions (EQ-5D), Global Assessment (GA), patient satisfaction and rate of subsequent surgery.

RESULTS

Some 3339 patients completed a 2-year follow-up. Of these, 2974 (89%) had decompression with LE and 365 underwent midline preserving surgery. Baseline scores were comparable between the groups. Mean ODI improvement at follow-up was 16.6 (SD = 20.0) in the LE group and 16.9 (SD = 20.2) in the midline preserving surgery group. In the propensity score-matched analysis the difference in improved ODI was 0.53 (95% confidence interval, CI -1.71 to 2.76; P = 0.64). The proportion of patients who showed a decreased ODI score of at least our defined minimal clinically important difference (=8) was 68.3% after LE and 67.0% after preserving the midline structures (P = 0.73). No significant differences were found in the improvement of NRS for leg and back pain, EQ-5D, GA or patient satisfaction. The rate of subsequent surgery was 5.5% after LE and 4.9% after midline preserving surgery without a significant difference in the propensity score-matched analysis (hazard ratio, HR 0.87; 95% CI 0.49-1.54; P = 0.64).

CONCLUSION

In this study on decompression techniques for LSS, there was no benefit in preserving the midline structures compared to LE 2 years after decompression. The conclusion is that the surgeon is free to choose the surgical method that is thought most suitable for the patient and the condition with which the patient presents.Level of Evidence: 3.

Trans-Sacral Epiduroscopic Ho:YAG Laser Ablation of the Ligamentum Flavum in a Live Pig

Introduction

For the aging population, surgery for lumbar spinal canal stenosis (LSCS) requires minimally invasive procedures. Recently, trans-sacral epiduroscopic laser decompression for lumbar disc herniation has been reported with good results. In this study, we devised a new method to perform trans-sacral epiduroscopic laser ablation of the ligamentum flavum (LF), known to be the major cause of LSCS. Using a live pig, this study aims to evaluate the efficacy, safety, and drawbacks of this procedure.

Methods

Using an epiduroscope, we observed intra-spinal canal structures and then examined the feasibility and problems of a decompression procedure to ablate the LF using holmium:YAG (Ho:YAG) laser. The pig was observed for behavioral changes and neurological deficits after the procedure. Histological analysis was performed to evaluate the amount of tissue ablation and damage to surrounding tissues.

Results

Although it was possible to partially ablate the LF using the Ho:YAG laser under epiduroscopy, it was difficult to maintain a clear field of view, and freely decompressing the target lesion has been a challenge. After the first two experiments, the pig neither showed abnormal behavior nor any signs of pain or paresis. However, in the third experiment, the pig died during the operation. On autopsy, no thermal or mechanical injury was noted around the ablated site, including the dura mater and nerve root. Histological analysis showed that the LF and lamina were deeply ablated as the laser power increased, and no damage was noted on surrounding tissues beyond a depth of 500 μm.

Conclusions

Although Ho:YAG laser could ablate the ligamentum and bone tissues without causing damage to surrounding tissues, it was difficult to completely decompress the LF under epiduroscopy. This method is a potentially highly invasive procedure that requires caution in its clinical application and needs further improvement in terms of the instruments and techniques used.

Comparison of 3 Different Minimally Invasive Surgical Techniques for Lumbar Spinal Stenosis: A Randomized Clinical Trial

IMPORTANCE

Operations for lumbar spinal stenosis is the most often performed surgical procedure in the adult lumbar spine. This study reports the clinical outcome of the 3 most commonly used minimally invasive posterior decompression techniques.

OBJECTIVE

To compare the effectiveness of 3 minimally invasive posterior decompression techniques for lumbar spinal stenosis.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial used a parallel group design and included patients with symptomatic and radiologically verified lumbar spinal stenosis without degenerative spondylolisthesis. Patients were enrolled between February 2014 and October 2018 at the orthopedic and neurosurgical departments of 16 Norwegian public hospitals. Statistical analysis was performed in the period from May to June 2021.

INTERVENTIONS

Patients were randomized to undergo 1 of the 3 minimally invasive posterior decompression techniques: unilateral laminotomy with crossover, bilateral laminotomy, and spinous process osteotomy.

MAIN OUTCOMES AND MEASURES

Primary outcome was change in disability measured with Oswestry Disability Index (ODI; range 0-100), presented as mean change from baseline to 2-year follow-up and proportions of patients classified as success (>30% reduction in ODI). Secondary outcomes were mean change in quality of life, disease-specific symptom severity measured with Zurich Claudication Questionnaire (ZCQ), back pain and leg pain on a 10-point numeric rating score (NRS), patient perceived benefit of the surgical procedure, duration of the surgical procedure, blood loss, perioperative complications, number of reoperations, and length of hospital stay.

RESULTS

In total, 437 patients were included with a median (IQR) age of 68 (62-73) years and 230 men (53%). Of the included patients, 146 were randomized to unilateral laminotomy with crossover, 142 to bilateral laminotomy, and 149 to spinous process osteotomy. The unilateral laminotomy with crossover group had a mean change of -17.9 ODI points (95% CI, -20.8 to -14.9), the bilateral laminotomy group had a mean change of -19.7 ODI points (95% CI, -22.7 to -16.8), and the spinous process osteotomy group had a mean change of -19.9 ODI points (95% CI, -22.8 to -17.0). There were no significant differences in primary or secondary outcomes among the 3 surgical procedures, except a longer duration of the surgical procedure in the bilateral laminotomy group.

CONCLUSIONS AND RELEVANCE

No differences in clinical outcomes or complication rates were found among the 3 minimally invasive posterior decompression techniques used to treat patients with lumbar spinal stenosis.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02007083.