What is the Rate of Revision Discectomies After Primary Discectomy on a National Scale?

Study on the clinical effect of percutaneous transforaminal endoscopic discectomy combined with annulus fibrosus repair in the treatment of single-segment lumbar disc herniation in young and middle-aged patients

Objective

To explore the clinical effect of percutaneous transforaminal endoscopic discectomy (PTED) combined with annulus fibrosus repair in the treatment of single-segment lumber disc herniation (LDH) in young and middle-aged patients.

Methods

Ninty-six patients with single-segment LDH admitted to Baoding First Central Hospital from March 2021 to November 2022 were selected in the retrospective study. The patients were divided into endoscopic group and combined group according to different surgical methods. The surgical conditions, VAS score and ODI score the two groups of patients were compared, as well as the postoperative review results.

Results

There were 50 patients in the endoscopic group the average operation time was 43.68 ± 10.77 minutes, the average intraoperative blood loss was 35.38 ± 10.02 ml, there were seven cases of surgical segment recurrence and 10 cases of postoperative intervertebral instability at the surgical segment. There were 46 patients in the combined group, the average operation time was 52.26 ± 8.39 minutes, the average intraoperative blood loss was 39.23 ± 9.02ml, there was one case of surgical segment recurrence and two cases of surgical segment intervertebral instability. The operation time (t=-4.328, P<0.01), postoperative recurrence cases (χ2=4.386, P<0.05) and intervertebral instability cases (χ2=5.366, P<0.05) of the two groups of patients). The difference was statistically significant. There was no significant difference in intraoperative blood loss between the two groups (t=-1.965, P>0.05). For six months after surgery, the differences in VAS and ODI scores between the two groups were statistically significant. In addition, there were statistically significant differences in the VAS scores and ODI scores of the two groups of patients at each time point after surgery compared with those before surgery (P<0.05).

Conclusion

The clinical efficacy of PTED combined with annulus fibrosus repair showed better clinical efficacy than PTED alone, and it can reduce the occurrence of surgical segment recurrence and intervertebral instability, suggesting that PTED combined with annulus fibrosus repair may be worthy of promotion in clinical practice.

Magnetic Resonance Imaging Evaluation of Multifidus Muscle in Patients with Low Back Pain after Microlumbar Discectomy Surgery

Cross-sectional area (CSA) and signal intensity ratio (SIR) of the multifidus muscle (MFM) on magnetic resonance imaging (MRI) was used to evaluate the extent of injury and atrophy of the MFM in patients with negative treatment outcomes following microlumbar discectomy (MLD). Negative treatment outcome was determined by pain score improvement of <50% compared to baseline. Patients in groups 1, 2, and 3 were evaluated at <4 weeks, 4-24 weeks, and >24 weeks postoperatively, respectively. The associations between the follow-up, surgery time and the changes in the MFM were evaluated. A total of 79 patients were included, with 22, 27, and 30 subjects in groups 1, 2, and 3, respectively. The MFM SIR of the ipsilateral side had significantly decreased in groups 2 (p = 0.001) and 3 (p < 0.001). The ipsilateral MFM CSA significantly decreased postoperatively in groups 2 (p = 0.04) and 3 (p = 0.006). The postoperative MRI scans found significant MFM changes on the ipsilateral side in patients with negative treatment outcomes regarding pain intensity following MLD. As the interval to the postoperative MRI scan increased, the changes in CSA of the MFM and change in T2 SIR of the MFM showed a tendency to increase.

Incidence and risk factors for five-year recurrent disc herniation after primary single-level lumbar discectomy

To identify the incidence and risk factors for five-year same-site recurrent disc herniation (sRDH) after primary single-level lumbar discectomy. Secondary outcome was the incidence and risk factors for five-year sRDH reoperation. A retrospective study was conducted using prospectively collected data and patient-reported outcome measures, including the Oswestry Disability Index (ODI), between 2008 and 2019. Postoperative sRDH was identified from clinical notes and the centre's MRI database, with all imaging providers in the region checked for missing events. The Kaplan-Meier method was used to calculate five-year sRDH incidence. Cox proportional hazards model was used to identify independent variables predictive of sRDH, with any variable not significant at the p < 0.1 level removed. Hazard ratios (HRs) were calculated with 95% confidence intervals (CIs). Complete baseline data capture was available for 733 of 754 (97.2%) consecutive patients. Median follow-up time for censored patients was 2.2 years (interquartile range (IQR) 1.0 to 5.0). sRDH occurred in 63 patients at a median 0.8 years (IQR 0.5 to 1.7) after surgery. The five-year Kaplan-Meier estimate for sRDH was 12.1% (95% CI 9.5 to 15.4), sRDH reoperation was 7.5% (95% CI 5.5 to 10.2), and any-procedure reoperation was 14.1% (95% CI 11.1 to 17.5). Current smoker (HR 2.12 (95% CI 1.26 to 3.56)) and higher preoperative ODI (HR 1.02 (95% CI 1.00 to 1.03)) were independent risk factors associated with sRDH. Current smoker (HR 2.15 (95% CI 1.12 to 4.09)) was an independent risk factor for sRDH reoperation. This is one of the largest series to date which has identified current smoker and higher preoperative disability as independent risk factors for sRDH. Current smoker was an independent risk factor for sRDH reoperation. These findings are important for spinal surgeons and rehabilitation specialists in risk assessment, consenting patients, and perioperative management.

Long-term outcome of redo discectomy for recurrent lumbar disc herniations

PURPOSE

Recurrent lumbar disc herniation (RLDH) is an important cause of morbidity and healthcare costs. The goal of this investigation is to assess surgical outcomes and their predictors in patients who underwent revision discectomy for RLDH, with a minimum follow-up of ten years, to shed light on the best treatment to offer to these patients.

METHODS

Patients who underwent revision discectomy to treat RLDH between 2004 and 2011 in our Department were enrolled. Demographic, clinical, and surgical data were collected. The need of third intervention for RLDH was the primary outcome. Patient's satisfaction, Core Outcome Measures Index, Oswestry Disability Index, and EuroQoL-5D scores were also evaluated.

RESULTS

This study includes 55 patients, with a mean follow-up time of 144 months [112-199]. In this period, a third intervention was needed in 30.9% (n = 17) of patients. Most recurrences took place in the first 2 years after the second surgery (58.8%, n = 10) and the risk of needing a third surgery decreased over time. After 5 years, the probability of not having surgery for recurrence was 71% [CI 95%: 60-84%], with a tendency to stabilize after that. An interval between the first discectomy and the surgery for recurrence shorter than 7.6 months was identified as a predictor for a second recurrence.

CONCLUSION

The risk of needing a third surgery seems to stabilize after five years. Patients with an early recurrence after the first discectomy seem to have a higher risk of a new recurrence, so an arthrodesis might be worth considering.

Reoperation Rates of Microendoscopic Discectomy Compared With Conventional Open Lumbar Discectomy: A Large-database Study

BACKGROUND

Microendoscopic discectomy for lumbar disc herniation has been shown to be as effective as traditional microdiscectomy or open discectomy in terms of clinical outcomes such as pain relief, and it is less invasive. Nevertheless, the reoperation rate for microendoscopic discectomy compared with microdiscectomy or open discectomy remains unclear, possibly due to difficulties in conducting follow-up of sufficient duration and in obtaining information about reoperation in other facilities.

QUESTIONS/PURPOSES

(1) What is the rate of reoperation after microendoscopic discectomy for primary lumbar disc herniation on a large scale at a median of 4 years postoperatively? (2) Is there any difference in revision rate at a median of 4 years and within 90 days postoperatively based on surgical method?

METHODS

We conducted a retrospective, comparative study of adult patients who underwent microendoscopic discectomy or microdiscectomy or open discectomy for lumbar disc herniation from April 2008 to October 2017 and who were followed until October 2020 using a commercially available administrative claims database from JMDC Inc. This claims-based database provided information on individual patients collected across multiple hospitals, which improved the accuracy of postoperative reoperation rates. We included 3961 patients who received microendoscopic discectomy or microdiscectomy or open discectomy between April 2008 and October 2017 in the JMDC claims database. After applying exclusion criteria, 50% (1968 of 3961) of patients were eligible for this study. Propensity score-weighted analyses were conducted in 646 patients in the microendoscopic discectomy group and in 1322 in the microdiscectomy or open discectomy group, with a median (IQR) of 4 years (3 to 6) of follow-up in both groups. Mean patient age was 42 ± 12 years in the microendoscopic discectomy group and 43 ± 12 years in the microdiscectomy or open discectomy group. Males accounted for 78% (505 of 646) of patients in the microendoscopic discectomy group and 79% (1050 of 1322) of patients in microdiscectomy or open discectomy group. The proportion of patients with diabetes mellitus in the microendoscopic discectomy group (10% [64 of 646]) was less than in the microdiscectomy or open discectomy group (15% [195 of 1322]). The primary outcome was Kaplan-Meier survivorship free from any type of additional lumbar spine surgery at a median of 4 years after the index surgery. The secondary outcome was survival probability using the Kaplan-Meier method with endpoints of any type of reoperation within 90 days after the index surgery. To determine which procedure had the higher revision rate, we conducted propensity score overlap weighting analysis, which controlled for potential confounding variables such as age, sex, comorbidities, and type of hospital as well as Cox proportional hazard models to estimate HRs and 95% confidence intervals (CIs).

RESULTS

The 5-year cumulative reoperation rate was 12% (95% CI 9% to 15%) in the microendoscopic discectomy group and 7% (95% CI 6% to 9%) in the microdiscectomy or open discectomy group. After controlling for potentially confounding variables like age, sex, and diabetes mellitus, the microendoscopic discectomy group had a higher reoperation risk than the microdiscectomy or open discectomy group (weighted HR 1.57 [95% CI 1.14 to 2.16]; p = 0.004). Within 90 days of the index surgery, after controlling for potentially confounding variables like age, sex, and diabetes mellitus, we found no difference between the microendoscopic discectomy group and microdiscectomy or open discectomy group in terms of risk of reoperation (weighted HR 1.38 [95% CI 0.68 to 2.79]; p = 0.38).

CONCLUSION

Given the higher reoperation risk with microendoscopic discectomy compared with microdiscectomy or open discectomy at a median of 4 years of follow-up, surgeons should select microdiscectomy or open discectomy, despite the current popularity of microendoscopic discectomy. The revision risk of microendoscopic discectomy compared with microdiscectomy or open discectomy in the long term remains unclear. Future large, prospective, multicenter cohort studies with long-term follow-up are needed to confirm the association between microendoscopic discectomy and risk of reoperation.

LEVEL OF EVIDENCE

Level Ⅲ, therapeutic study.

The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain

Introduction

Painful lumbar spinal disorders represent a leading cause of disability in the US and worldwide. Interventional treatments for lumbar disorders are an effective treatment for the pain and disability from low back pain. Although many established and emerging interventional procedures are currently available, there exists a need for a defined guideline for their appropriateness, effectiveness, and safety.

Objective

The ASPN Back Guideline was developed to provide clinicians the most comprehensive review of interventional treatments for lower back disorders. Clinicians should utilize the ASPN Back Guideline to evaluate the quality of the literature, safety, and efficacy of interventional treatments for lower back disorders.

Methods

The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations. Experts from the fields of Anesthesiology, Physiatry, Neurology, Neurosurgery, Radiology, and Pain Psychology developed the ASPN Back Guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Scopus, and meeting abstracts to identify and compile the evidence (per section) for back-related pain. Search words were selected based upon the section represented. Identified peer-reviewed literature was critiqued using United States Preventive Services Task Force (USPSTF) criteria and consensus points are presented.

Results

After a comprehensive review and analysis of the available evidence, the ASPN Back Guideline group was able to rate the literature and provide therapy grades to each of the most commonly available interventional treatments for low back pain.

Conclusion

The ASPN Back Guideline represents the first comprehensive analysis and grading of the existing and emerging interventional treatments available for low back pain. This will be a living document which will be periodically updated to the current standard of care based on the available evidence within peer-reviewed literature.

Reoperations after primary and revision lumbar discectomy: study of a national-level cohort with eight years follow-up

BACKGROUND CONTEXT

Published rates for disc reherniation following primary discectomy are around 6%, but the ultimate reoperation outcomes in patients after receiving revision discectomy are not well understood. Additionally, any disparity in the outcomes of subsequent revision discectomy (SRD) versus subsequent lumbar fusion (SLF) following primary/revision discectomy remains poorly studied.

PURPOSE

To determine the 8-year SRD/SLF rates and time until SRD/SLF after primary/revision discectomy respectively.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Patients undergoing primary or revision discectomy, with records in the PearlDiver Patient Records Database from the years 2010 to 2019.

OUTCOME MEASURES

Subsequent surgery type and time to subsequent surgery.

METHODS

Patients were grouped into primary or revision discectomy cohorts based off of the nature of "index" procedure (primary or revision discectomy) using ICD9/10 and CPT procedure codes from 2010 to 19 insurance data sets in the PearlDiver Patient Records Database. Preoperative demographic data was collected. Outcome measures such as subsequent surgery type (fusion or discectomy) and time to subsequent surgery were collected prospectively in PearlDiver Mariner database. Statistical analysis was performed using BellWeather statistical software. A Kaplan-Meier survival analysis of time to SLF/SRD was performed on each cohort, and log-rank test was used to compare the rates of SLF/SRD between cohorts.

RESULTS

A total of 20,147 patients were identified (17,849 primary discectomy, 2,298 revision discectomy). The 8-year rates of SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01) and SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) were higher after revision versus primary discectomy. Time to SLF was shorter after revision versus primary discectomy (709 vs. 886 days, p<.01). After both primary and revision discectomy, the 8-year rate of SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) is greater than SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01).

CONCLUSIONS

Compared to primary discectomy, revision discectomy has higher rates of SLF (10.4% vs. 6.2%), and faster time to SLF (2.4 vs. 1.9 years) at 8-year follow up.

Additional operations after surgery for lumbar disc prolapse : indications, type of surgery, and long-term follow-up of primary operations performed from 2007 to 2008

AIMS

Lumbar disc prolapse is a frequent indication for surgery. The few available long-term follow-up studies focus mainly on repeated surgery for recurrent disease. The aim of this study was to analyze all reasons for additional surgery for patients operated on for a primary lumbar disc prolapse.

METHODS

We retrieved data from the Swedish spine register about 3,291 patients who underwent primary surgery for a lumbar disc prolapse between January 2007 and December 2008. These patients were followed until December 2020 to record all additional lumbar spine operations and the reason for them.

RESULTS

In total, 681 of the 3,291 patients (21%) needed one or more additional operations. More than three additional operations was uncommon (2%; 15/906). Overall, 906 additional operations were identified during the time period, with a mean time to the first of these of 3.7 years (SD 3.6). The most common reason for an additional operation was recurrent disc prolapse (47%; 426/906), followed by spinal stenosis or degenerative spondylolisthesis (19%; 176/906), and segmental pain (16%; 145/906). The most common surgical procedures were revision discectomy (43%; 385/906) and instrumented fusion (22%; 200/906). Degenerative spinal conditions other than disc prolapse became a more common reason for additional surgery with increasing length of follow-up. Most patients achieved the minimally important change (MIC) for the patient-reported outcomes after the index surgery. After the third additional spinal operation, only 20% (5/25) achieved the MIC in terms of leg pain, and 29% (7/24) in terms of the EuroQol five-dimension index questionnaire visual analogue scale.

CONCLUSION

More than one in five patients operated on for a lumbar disc prolapse underwent further surgery during the 13-year follow-up period. Recurrent disc prolapse was the most common reason for additional surgery, followed by spinal stenosis and segmental pain. This study shows that additional operations after primary disc surgery are needed more frequently than previously reported, and that the outcome profoundly deteriorates after the second additional operation. The findings from this study can be used in the shared decision-making process. Cite this article: Bone Joint J 2022;104-B(5):627-632.

Emerging Issues Questioning the Current Treatment Strategies for Lumbar Disc Herniation

Lumbar disc herniation is among the common phenotypes of degenerative lumbar spine diseases, significantly affecting patients' quality of life. The practice pattern is diverse. Choosing conservative measures or surgical treatments is still controversial in some areas. For those who have failed conservative treatment, surgery with or without instrumentation is recommended, causing significant expenditures and frustrating complications, that should not be ignored. In the article, we performed a literature review and summarized the evidence by subheadings to unravel the cons of surgical intervention for lumbar disc herniation. There are tetrad critical issues about surgical treatment of lumbar disc herniation, i.e., favorable natural history, insufficient evidence in a recommendation of fusion surgery for patients, metallosis, and implant removal. Firstly, accumulating evidence reveals immune privilege and auto-immunity hallmarks of human lumbar discs within the closed niche. Progenitor cells within human discs further expand the capacity with the endogenous repair. Clinical watchful follow-up studies with repeated diagnostic imaging reveal spontaneous resolution for lumbar disc herniation, even calcified tissues. Secondly, emerging evidence indicates long-term complications of lumbar fusion, such as adjacent segment disease, pseudarthrosis, implant failure, and sagittal spinal imbalance, which get increasing attention. Thirdly, systemic and local reactions (metallosis) for metal instrumentation have been noted with long-term health concerns and toxicity. Fourthly, the indications and timing for spinal implant removal have not reached a consensus. Other challenging issues include postoperative lumbar stiffness. The review provided evidence from a negative perspective for surgeons and patients who attempt to choose surgical treatment. Collectively, the emerging underlying evidence questions the benefits of traditional surgery for patients with lumbar disc herniation. Therefore, the long-term effects of surgery should be closely observed. Surgical decisions should be made prudently for each patient.

The association between changes in multifidus muscle morphology and back pain scores following discectomy surgery for lumbar disc herniation: a systematic review and meta-analysis

PURPOSE

To evaluate the impact of discectomy on back muscles (e.g. multifidus muscle (MM)) morphology in patients with lumbar disc herniation (LDH) following discectomy surgery, address the association of back muscles morphology with pain score preoperatively and post-operatively, and investigate the relationships between the changes from pre- to post-operative back muscles measurements and pain score (primary outcome) and disability score (secondary outcome) change following discectomy if any.

METHODS

We searched three online databases for randomized controlled trials (RCTs) and observational studies. In LDH patients, eligible for discectomy surgery, pre- and post-operative and the changes from pre- to post-operative of back and/or leg pain with Visual Analogue Scale (VAS) and multifidus muscle morphology, were considered as primary outcomes. Cochrane Risk-of-Bias 2 tool and Newcastle-Ottawa Scale (NOS) were used to assess the methodological quality of RCTs and observational studies, respectively. Standardize mean difference (SMD) with 95% confidence intervals (CI) was evaluated. A meta-regression analysis was conducted. GRADE approach was used to summarize the strength of evidence.

RESULTS

One RCT and five observational studies were included in the analysis of 489 patients with LDH undergoing discectomy surgery. The mean overall follow-up was 64.9 weeks (6 to 148.7 weeks). There was a significant negative relationship between the change from pre- to post-operative cross-sectional area (CSA) in MM and change in VAS back pain [regression coefficient = -0.01, (95% CI = -0.02, -0.01), p = 0.044] after discectomy surgery. No significant relationship between preoperative CSA in MM and preoperative/post-operative clinical (any of the follow-up periods) scores could be established.

CONCLUSION

The results of this study found very low-quality grade evidence for an association between higher reduction of CSA in MM and less reductions of back pain scores following discectomy surgery for patients with LDH. Due to the heterogeneity and methodological limitations, further studies will improve understanding and aid preoperative counselling.

Retrospective Analysis of Reoperation Rate After Standard Lumbar Discectomy and Microdiscectomy - Single Center Experience

Discectomy is a surgical procedure in the treatment of lumbar disc herniation (LDH) if sciatica or neurological deficits occur and still persist after a course of conservative therapy. Standard discectomy (SD) and microdiscectomy (MD) are still equal in curent clinical practice. Many retrospective and prospective studies have shown that there is no clinically significant difference in the functional outcome after two treatment modalities.

The aim of our study was to determine whether there are differences in the incidence of reoperation after performing SD and MD.

The research included 545 patients with average period of postoperative follow-up of approximately 5.75 years. Standard discectomy was performed in 393 patients (72.11%), and micro-discectomy in 152 (27.8%) patients. The total number of reoperated patients was 37/545, or 6.78%. In the SD group, the number of reoperated patients was 33/393 (8.39%) and in the MD group 4/152 or 2.63%. Statistically significant difference (p <0.05) was recorded in favor of the MD group.

Although it has been proven that both SD and MD give good endpoints of treatment and similar functional recovery, the advantage is given to microdiscectomy due to statistically significantly lower rates of recurrent herniation. This result is attributed to better visualization of neural structures and pathological substrates, as well as their mutual relationship.

15-year survivorship analysis of an interspinous device in surgery for single-level lumbar disc herniation

BACKGROUND

Interspinous devices have been introduced as alternatives to decompression or fusion in surgery for degenerative lumbar diseases. This study aimed to investigate 15-year survivorship and risk factors for reoperation of a Device for Intervertebral Assisted Motion (DIAM) in surgery for 1-level lumbar disc herniation (LDH).

METHODS

A total of 94 patients (54 men and 40 women) underwent discectomy and DIAM implantation for 1-level LDH, with a mean follow-up of 12.9 years (range, 6.3-15.3 years). The mean age was 46.2 years (range, 21-65 years). Sixty-two patients underwent DIAM implantation for L4-5, 27 for L5-6, and 5 for L3-4. Reoperations due to any reason associated with DIAM implantation level or adjacent levels were defined as failure and used as the end point of determining survivorship.

RESULTS

During the 15-year follow-up, 8 patients (4 men and 4 women) underwent reoperation due to recurrence of LDH at the DIAM implantation level, a reoperation rate of 8.5%. The mean time to reoperation was 6.5 years (range, 0.8-13.9 years). Kaplan-Meier analysis showed a cumulative survival rate of the DIAM implantation of 97% at 5 years, 93% at 10 years, and 92% at 15 years after surgery; the cumulative reoperation rate of the DIAM implantation was 3% at 5 years, 7% at 10 years, and 8% at 15 years after surgery. Mean survival time was predicted to be 14.5 years (95% CI, 13.97-15.07). The log-rank test and Cox proportional hazard model showed that age, sex, and location did not significantly affect the reoperation rate of DIAM implantation.

CONCLUSIONS

Our results showed that DIAM implantation significantly decreased reoperation rate for LDH in the 15-year survivorship analysis. We suggest that DIAM implantation could be considered a useful intermediate step procedure for LDH surgery. To the best of our knowledge, this is the longest follow-up study in which surgical outcomes of interspinous device surgery were reported.

Characteristics and Short-Term Surgical Outcomes of Patients with Recurrent Lumbar Disc Herniation after Percutaneous Laser Disc Decompression

Background and Objectives: Although percutaneous laser disc decompression (PLDD) is one of the common treatment methods for patients with lumbar disc herniation (LDH), the recurrence of LDH after PLDD is estimated at 4–5%. This study compares the preoperative clinical data and clinical outcomes of patients who underwent primary microendoscopic discectomy (MED) or MED following PLDD. Materials and Methods: We retrospectively analyzed 2678 patients who underwent MED for LDH. The PLDD group included patients with previous PLDD history at the same level of LDH, and a matched control group was created using propensity score matching for age, sex, and body mass index. Preoperative data, preoperative radiographic findings, and surgical data of the groups were compared. To compare postoperative changes in clinical scores between the groups, a mixed-effect model was used. Results: As a result, 42 patients (1.6%) had previously undergone PLDD, and a control group with 42 patients were created. The disc degeneration severity was not significantly different between the groups. However, Modic changes were more frequent in the PLDD group than in the matched control group (p = 0.028). There were no significant differences in dural adhesion rate or surgery-related complications including dural injury, length of stay, and recurrence rate of LDH after surgery. In addition, the improvement of clinical scores did not significantly differ between the two groups (p = 0.112, 0.913, respectively). Conclusions: We concluded that patients with recurrent LDH after PLDD have advanced endplate degeneration, which may reflect endplate injury from a previous PLDD. However, a previous history of PLDD does not have a negative impact on the clinical result of MED.

Lumbar Discectomy and Reoperation Among Workers' Compensation Cases in Florida and New York: Are Treatment Trends Similar to Other Payer Types?

The aim of this study was to better understand current treatment trends and revision rates for lumbar disc herniation (LDH) in the workers’ compensation (WC) population compared with other payer types.

Artificial intelligence predicts disk re-herniation following lumbar microdiscectomy: development of the "RAD" risk profile

PURPOSE

Surgical treatment of herniated lumbar intervertebral disks is a common procedure worldwide. However, recurrent herniated nucleus pulposus (re-HNP) may develop, complicating outcomes and patient management. The purpose of this study was to utilize machine-learning (ML) analytics to predict lumbar re-HNP, whereby a personalized risk prediction can be developed as a clinical tool.

METHODS

A retrospective, single center study was conducted of 2630 consecutive patients that underwent lumbar microdiscectomy (mean follow-up: 22-months). Various preoperative patient pain/disability/functional profiles, imaging parameters, and anthropomorphic/demographic metrics were noted. An Extreme Gradient Boost (XGBoost) classifier was implemented to develop a predictive model identifying patients at risk for re-HNP. The model was exported to a web application software for clinical utility.

RESULTS

There were 1608 males and 1022 females, 114 of whom experienced re-HNP. Primary herniations were central (65.8%), paracentral (17.6%), and far lateral (17.1%). The XGBoost algorithm identified multiple re-HNP predictors and was incorporated into an open-access web application software, identifying patients at low or high risk for re-HNP. Preoperative VAS leg, disability, alignment parameters, elevated body mass index, symptom duration, and age were the strongest predictors.

CONCLUSIONS

Our predictive modeling via an ML approach of our large-scale cohort is the first study, to our knowledge, that has identified significant risk factors for the development of re-HNP after initial lumbar decompression. We developed the re-herniation after decompression (RAD) profile index that has been translated into an online screening tool to identify low-high risk patients for re-HNP. Additional validation is needed for potential global implementation.

Do Markers of Inflammation and/or Muscle Regeneration in Lumbar Multifidus Muscle and Fat Differ Between Individuals with Good or Poor Outcome Following Microdiscectomy for Lumbar Disc Herniation?

STUDY DESIGN

Observational study.

OBJECTIVE

The aim of this study was to evaluate whether inflammatory and/or muscle regeneration markers in paraspinal tissues (multifidus muscle/fat) during microdiscectomy surgery in patients with lumbar disc herniation (LDH) with radiculopathy, differ between individuals with good or poor outcome.

SUMMARY OF BACKGROUND DATA

Structural back muscle changes, including fat infiltration, muscle atrophy, and fiber changes, are ubiquitous with LBP and are thought to be regulated by inflammatory and regeneration processes. Muscle changes might be relevant for recovery after microdiscectomy, but a link between expression of inflammatory and muscle regeneration genes in paraspinal tissues and clinical outcome has not been tested.

METHOD

Paraspinal tissues from deep multifidus muscles and fat (intramuscular, sub-cutaneous, epidural) were harvested from twenty-one patients with LDH undergoing microdiscectomy surgery. Quantitative polymerase chain reaction (qPCR) measured expression of 10 genes. Outcome was defined as good (visual analogue scale (VAS) low back pain (LBP)+) or poor (VAS LBP-) by an improvement of >33% or ≤33% on the pain VAS, respectively. Good functional improvement was defined as 25% improvement on the physical functioning scale (PFS).

RESULTS

Brain-derived neurotrophic factor expression in deep multifidus was 91% lower (P = 0.014) in the VAS LBP- than VAS LBP+ group. Expression of interleukin-1β in subcutaneous fat was 48% higher (P = 0.026) in the VAS LBP- than VAS LBP+ group. No markers differed based on PFS.

CONCLUSION

Results show a relationship between impaired muscle regeneration profile in multifidus muscle and poor outcome following microdiscectomy for LDH. Inflammatory dysregulation in subcutaneous fat overlying the back region might predict poor surgical outcome.Level of Evidence: 4.

Analysis of the influence of species, intervertebral disc height and Pfirrmann classification on failure load of an injured disc using a novel disc herniation model

BACKGROUND CONTEXT

Annular repair devices offer a solution to recurrent disc herniations by closing an annular defect and lowering the risk of reherniation. Given the significant risk of neurologic injury from device failure it is imperative that a reliable preclinical model exists to demonstrate a high load to failure for the disc repair devices.

PURPOSE

To establish a preclinical model for disc herniation and demonstrate how changes in species, intervertebral disc height and Pfirrmann classification impacts failure load on an injured disc. We hypothesized that: (1) The force required for disc herniation would be variable across disc morphologies and species, and (2) for human discs the force to herniation would inversely correlate with the degree of disc degeneration.

STUDY DESIGN

Animal and human cadaveric biomechanical model of disc herniation.

METHODS

We tested calf lumbar spines, bovine tail segments and human lumbar spines. We first divided individual lumbar or tail segments to include the vertebral bodies and disc. We then hydrated the specimens by placing them in a saline bath overnight. A magnetic resonance images were acquired from human specimens and a Pfirrmann classification was made. A stab incision measuring 25% of the diameter of the disc was then done to each specimen along the posterior intervertebral disc space. Each specimen was placed in custom test fixtures on a servo-hydraulic test frame (MTS, Eden Prarie, MN) such that the superior body was attached to a 10,000 lb load cell and the inferior body was supported on the piston. A compressive ramping load was placed on the specimen in load control at 4 MPa/sec stopping at 75% of the disc height. Load was recorded throughout the test and failure load calculated. Once the test was completed each specimen was sliced through the center of the disc and photos were taken of the cut surface.

RESULTS

Fifteen each of calf, human, and bovine tail segments were tested. The failure load varied significantly between specimens (p<.001) with human specimens having the highest average failure load (8154±2049 N). Disc height was higher for lumbar/bovine tail segments as compared to calf specimens (p<.001) with bovine tails having the highest disc height (7.1±1.7 mm). Similarly, human lumbar discs had a cross sectional area that was greater than both bovine tail/calf lumbar spines (p<.001). There was no correlation between disc height and failure load within each individual species (p>.05). Cross sectional area and failure load did not correlate with failure load for human lumbar spine and bovine tails (p>.05) but did correlate with calf spine (r=0.53, p=.04). There was a statistically significant inverse correlation between disc height and Pfirrmann classification for human lumbar spines (r=-0.84, p<.001). There was also a statistically significant inverse relationship between Pfirrmann classification and failure load (r=-0.58, p=.02).

CONCLUSIONS

We have established a model for disc herniation and have shown how results of this model vary between species, disc morphology, and Pfirrmann classification. Both hypotheses were accepted: The force required for disc herniation was variable across species, and the force to herniation for human spines was inversely correlated with the degree of disc degeneration. We recommend that models using human intervertebral discs should include data on Pfirrmann classification, while biomechanical models using calf spines should report cross sectional area. Failure loads do not vary based on dimensions for bovine tails.

CLINICAL SIGNIFICANCE

Our analysis of models for disc herniation will allow for quicker, reliable comparisons of failure forces required to induce a disc herniation. Future work with these models may facilitate rapid testing of devices to repair a torn/ruptured annulus.

A challenging playing field: Identifying the endogenous impediments to annulus fibrosus repair

Intervertebral disc (IVD) herniations, caused by annulus fibrosus (AF) tears that enable disc tissue extrusion beyond the disc space, are very prevalent, especially among adults in the third to fifth decade of life. Symptomatic herniations, in which the extruded tissue compresses surrounding nerves, are characterized by back pain, numbness, and tingling and can cause extreme physical disability. Patients whose symptoms persist after nonoperative intervention may undergo surgical removal of the herniated tissue via microdiscectomy surgery. The AF, however, which has a poor endogenous healing ability, is left unrepaired increasing the risk for re-herniation and pre-disposing the IVD to degenerative disc disease. The lack of understanding of the mechanisms involved in native AF repair limits the design of repair systems that overcome the impediments to successful AF restoration. Moreover, the complexity of the AF structure and the challenging anatomy of the repair environment represents a significant challenge for the design of new repair devices. While progress has been made towards the development of an effective AF repair technique, these methods have yet to demonstrate long-term repair and recovery of IVD biomechanics. In this review, the limitations of endogenous AF healing are discussed and key cellular events and factors involved are highlighted to identify potential therapeutic targets that can be integrated into AF repair methods. Clinical repair strategies and their limitations are described to further guide the design of repair approaches that effectively restore native tissue structure and function.

Intra- and Post-Complications of Cervical Laminoplasty for the Treatment of Cervical Myelopathy: An Analysis of a Nationwide Database

STUDY DESIGN

Retrospective database study.

OBJECTIVE

To assess the intra- and postoperative complications of cervical laminoplasty and to evaluate the effect of intraoperative neuromonitoring use on postoperative limb paralysis incidence.

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty is a known procedure for the management of cervical spondylotic myelopathy (CSM).

METHODS

This was a retrospective study of 532 patients with CSM who underwent cervical laminoplasty between 2007 and the first quarter of 2016 using the Humana subset of the PearlDiver Database. The database was queried using the relevant International Classification of Diseases (ICD-9 and ICD-10) codes for CSM and Current Procedural Terminology (CPT) codes for cervical laminoplasty. The intra- and postoperative incidence of surgical and medical complications and reoperations was then determined and was compared with a propensity score-matched cohort of patients who had posterior laminectomy and fusion (490 patients in each group), using multivariate logistic regression analysis.

RESULTS

Laminoplasty was associated with a lower incidence of dysphagia (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.16-0.79; P = 0.014), 30-day readmission (OR = 0.51, 95% CI = 0.35-0.75; P < 0.001), urinary tract infection (OR = 0.58, 95% CI = 0.37-0.93; P = 0.023), and incision and drainage, exploration or evacuation (OR = 0.28, 95% CI = 0.08-0.79; P = 0.026). The use of intraoperative neuromonitoring was associated with a non-significant lower incidence of limb paralysis within 1 and 3 months postoperatively (OR = 0.52 and 0.51, 95% CI = 0.23-1.19 and 0.23-1.11; P = 0.119 and 0.091, respectively).

CONCLUSION

Compared with posterior laminectomy and fusion, laminoplasty had lower rates of dysphagia, urinary tract infection, and 30-day readmission. The use of intraoperative neuromonitoring was associated with a lower risk of postoperative limb paralysis, but it did not achieve statistical significance.

LEVEL OF EVIDENCE

4.

Effect of Nicotine Dependence and Smoking on Revision Diskectomy After Single-Level Lumbar Diskectomy

Removal of a herniated disk that is causing neural compression is among the most common indications for spinal surgery. Previous population database studies of risk factors for reoperation after this procedure analyzed small to medium numbers of patients. To date, no study has concurrently assessed the effect of modifiable risk factors, such as smoking and nicotine dependence, with a large number of patients. Data were obtained with commercially available software that houses de-identified data for several major US health care systems. A database search was conducted to find all patients who had undergone lumbar diskectomy. Obesity, scoliosis, spondylolisthesis, and depression were excluded as possible confounding variables. The remaining patients were divided into smoking and nonsmoking groups. Those who had undergone revision lumbar diskectomy within 2 years were counted. Pearson's chi-square statistical test was used to determine significance at P<.05. Of the 50 million patient records in the software platform, 53,360 patients were identified who had undergone single-level lumbar diskectomy. Of these, 26,980 fulfilled the inclusion criteria. A total of 890 of those patients had undergone revision lumbar diskectomy within 2 years of their original procedure. Those who smoked were found to have a relative risk of 2.47 compared with nonsmokers (95% confidence interval, 2.17-2.82; P<.0001). Nicotine dependence and smoking had a significant effect on the rate of reoperation. These findings support the importance of preoperative assessment of modifiable risk factors and their effects on surgical complications. [Orthopedics. 2020;43(5):e438-e441.].

How does preoperative opioid use impact postoperative health-related quality of life scores for patients undergoing lumbar microdiscectomy?

BACKGROUND CONTEXT

Narcotic use amongst patients suffering from lumbar radiculopathy is common, but the clinical benefit of narcotics for lumbar radiculopathy is likely minimal. It is unknown what the impact of preoperative use of narcotics has on outcomes related to lumbar microdiscectomy.

PURPOSE

Determine the impact that preoperative opioid use has on postoperative outcomes after lumbar microdisectomy.

STUDY DESIGN

Retrospective analysis of a prospectively collected database.

PATIENT SAMPLE

One hundred and twenty-six patients undergoing a microdiscectomy for a lumbar disc herniation.

OUTCOME MEASURES

Patient-reported outcomes measurement information system mental health scores (PROMIS MHS), patient-reported outcomes measurement information system physical health scores (PROMIS PHS) and oswestry disability index (ODI).

METHODS

We analyzed a prospectively collected database of patients undergoing a lumbar microdiscectomy for preoperative opioid use. We measured the severity of lumbar pathology on MRI based on degree of facet/disc degeneration and cross-sectional area of the dural tube at the disc herniation. We tracked PROMIS MHS, PROMIS PHS and ODI for patients both preoperatively and postoperatively. A Mann-Whitney test was used to compare HRQOL scores and time to MCID for the opioid using cohort (OC) and the nonopioid using cohort (non-OC). We performed a linear regression analysis to determine correlation between preoperative opioid use and postoperative HRQOLs.

RESULTS

There were 44 of 126 microdiscectomy patients in the OC (32.5%). There was no difference in the dural cross-sectional area (p=.91), degree of facet degeneration (p=.38), or disc degeneration (p=.5) between OC and non-OC. There were no differences in PROMIS PHS, PROMIS MHS or ODI between the OC and non-OC at the preoperative visit and all postoperative time points. There were no differences in time to reach MCID between the OC and non-OC for ODI (p=.9), PROMIS PHS (p=.64) or PROMIS MHS (p=.90). At three months out from surgery there was a statistically significant correlation between pre-op opioid use and ODI (p=.02), PROMIS MHS (p=.02) and PROMIS PHS (p=.049).

CONCLUSIONS

Our results demonstrate that patients that use opioids prior to lumbar microdiscectomy have equivalent postoperative outcomes as those that do not use opioids. Use of higher doses of opioids is associated with worse short-term outcomes.

Comparison of biomechanical studies of disc repair devices based on a systematic review

BACKGROUND CONTEXT

A variety of solutions have been suggested as candidates for the repair of the annulus fibrosis (AF), with the ability to withstand physiological loads of paramount importance.

PURPOSE

The objective of our study was to capture the scope of biomechanical test models of AF repairs. We hypothesized that common test parameters would emerge.

STUDY DESIGN

Systematic Review METHODS: PubMed and EMBASE databases were searched for studies in English including the keywords "disc repair AND animal models," "disc repair AND cadaver spines," "intervertebral disc AND biomechanics," and "disc repair AND biomechanics." This list was further limited to those studies which included biomechanical results from annular repair in animal or human spinal segments from the cervical, thoracic, lumbar and/or coccygeal (tail) segments. For each study, the method used to measure the biomechanical property and biomechanical test results were documented.

RESULTS

A total of 2,607 articles were included within our initial analysis. Twenty-two articles met our inclusion criteria. Significant variability in terms of species tested, measurements used to quantify annular repair strength, and the method/direction/magnitude that forces were applied to a repaired annulus were found. Bovine intervertebral disc was most commonly used model (6 of 22 studies) and the most common mechanical property reported was the force required for failure of the disc repair device (15 tests).

CONCLUSIONS

Our hypothesis was rejected; no common features were identified across AF biomechanical models and as a result it was not possible to compare results of preclinical testing of annular repair devices. Our analysis suggests that a standardized biomechanical model that can be repeatably executed across multiple laboratories is required for the mechanical screening of candidates for AF repair.

CLINICAL SIGNIFICANCE

This literature review provides a summary of preclinical testing of annular repair devices for clinicians to properly evaluate the safety/efficacy of developing technology designed to repair annular defects after disc herniations.

International Society for the Advancement of Spine Surgery Policy 2019-Surgical Treatment of Lumbar Disc Herniation with Radiculopathy

Lumbar disc herniation (LDH) is a frequent cause of low back pain and radiculopathy, disability, and diminution in quality of life. While nonsurgical care remains the mainstay of initial treatment, symptoms that persist for prolonged periods of time are well treated with discectomy surgery. A large body of evidence shows that, in patients with unremitting symptoms despite a reasonable period of nonsurgical treatment, discectomy surgery is safe and efficacious. In patients with symptoms lasting greater than 6 weeks, various forms of discectomy (open, microtubular, and endoscopic) are superior to continued nonsurgical treatment. The small but significant proportion of patients with recurrent disc herniation experience less improvement overall than patients who do not experience reherniation after primary discectomy. Lumbar discectomy patients with large annular defects (≥6 mm wide) are at a higher risk for recurrent herniation and revision surgery. Annular closure via a bone-anchored device has been shown to decrease the rate of recurrent disc herniation and associated reoperation in these high-risk patients. After a detailed review of the literature, current clinical evidence supports discectomy (open, microtubular, or endoscopic discectomy) as a medically necessary procedure for the treatment of LDH with radiculopathy in indicated patients. Furthermore, there is new scientific evidence that supports the use of bone-anchored annular closure in patients with large annular defects, who are at greater risk for recurrent disc herniation.

Improving Cell Therapy Survival and Anabolism in Harsh Musculoskeletal Disease Environments

Cell therapies are an up and coming technology in orthopedic medicine that has the potential to provide regenerative treatments for musculoskeletal disease. Despite numerous cell therapies showing preclinical success for common musculoskeletal indications of disc degeneration and osteoarthritis, there have been mixed results when testing these therapies in humans during clinical trials. A theory behind the mixed success of these cell therapies is that the harsh microenvironments of the disc and knee they are entering inhibit their anabolism and survival. Therefore, there is much ongoing research looking into how to improve the survival and anabolism of cell therapies within these musculoskeletal disease environments. This includes research into improving cell function under specific microenvironmental conditions known to exist in the intervertebral disc (IVD) and knee environment such as hypoxia, low-nutrient conditions, hyperosmolarity, acidity, and inflammation. This research also includes improving differentiation of cells into desired native cell phenotypes to better enhance their survival and anabolism in the knee and IVD. This review highlights the effects of specific musculoskeletal microenvironmental challenges on cell therapies and what research is being done to overcome these challenges. Impact statement While there has been significant clinical interest in using cell therapies for musculoskeletal pathologies in the knee and intervertebral disc, cell therapy clinical trials have had mixed outcomes. The information presented in this review includes the environmental challenges (i.e., acidic pH, inflammation, hyperosmolarity, hypoxia, and low nutrition) that cell therapies experience in these pathological musculoskeletal environments. This review summarizes studies that describe various approaches to improving the therapeutic capability of cell therapies in these harsh environments. The result is an overview of what approaches can be targeted and/or combined to develop a more consistent cell therapy for musculoskeletal pathologies.

Novel Intervertebral Technologies

Surgical procedures, such as spinal fusion and disk replacement, are commonly used for treatment following failure of conservative treatment in degenerative spine disease. However, there is growing consensus that currently available surgical technologies may have long-term inefficacy for successful management. Intervertebral disk degeneration is the most common manifestation of degenerative spine disease, hence, replacement/repair of this tissue is an important component of surgical treatment. Restoration of spinal alignment and preservation of natural kinematics is also essential to a good outcome. This article reviews novel intervertebral implant technologies that have the potential to significantly impact elective spine surgery for degenerative spine disease.

Closing the Treatment Gap for Lumbar Disc Herniation Patients with Large Annular Defects: A Systematic Review of Techniques and Outcomes in this High-risk Population

Lumbar disc herniation (LDH) is one of the most common spinal pathologies and can be associated with debilitating pain and neurological dysfunction. Discectomy is the primary surgical intervention for LDH and is typically successful. Yet, some patients experience recurrent LDH (RLDH) after discectomy, which is associated with worse clinical outcomes and greater socioeconomic burden. Large defects in the annulus fibrosis are a significant risk factor for RLDH and present a critical treatment challenge. It is essential to identify reliable and cost-effective treatments for this at-risk population. A systematic review of the PubMed and Embase databases was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies describing the treatment of LDH patients with large annular defects. The incidence of large annular defects, measurement technique, RLDH rate, and reoperation rate were compiled and stratified by surgical technique. The risk of bias was scored for each study and for the identification of RLDH and reoperation. Study heterogeneity and pooled estimates were calculated from the included articles. Fifteen unique studies describing 2,768 subjects were included. The pooled incidence of patients with a large annular defect was 44%. The pooled incidence of RLDH and reoperation following conventional limited discectomy in this population was 10.6% and 6.0%, respectively. A more aggressive technique, subtotal discectomy, tended to have lower rates of RLDH (5.8%) and reoperation (3.8%). However, patients treated with subtotal discectomy reported greater back and leg pain associated with disc degeneration. The quality of evidence was low for subtotal discectomy as an alternative to limited discectomy. Each report had a high risk of bias and treatments were never randomized. A recent randomized controlled trial with 550 subjects examined an annular closure device (ACD) and observed significant reductions in RLDH and reoperation rates (>50% reduction). Based on the available evidence, current discectomy techniques are inadequate for patients with large annular defects, leaving a treatment gap for this high-risk population. Currently, the strongest evidence indicates that augmenting limited discectomy with an ACD can reduce RLDH and revision rates in patients with large annular defects, with a low risk of device complications.

Cages in ACDF are Associated With a Higher Nonunion Rate Than Allograft: A Stratified Comparative Analysis of 6130 Patients

STUDY DESIGN

A retrospective database review.

OBJECTIVE

The purpose of this study was to analyze the rate of nonunion in patients treated with structural allograft and intervertebral cages in anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Existing literature consists primarily of single-center studies with inconsistent findings.

METHODS

We performed a retrospective analysis of 6130 patients registered in the PearlDiver national database through Humana Insurance from 2007 to 2016. All ACDF patients with anterior plating who were active in the database for at least 1 year were included in the study. Patients with a fracture history within 1 year of intervention, past arthrodesis of hand, foot, or ankle, or a planned posterior approach were excluded from the study. Patients were stratified by number of levels treated, tobacco use, and diabetic condition. Nonunion rates of structural allograft and intervertebral cage groups after 1 year were compared using Chi-squared analyses.

RESULTS

Four thousand sixty-three patients were included in the allograft group, while 2067 were included in the cage group. Overall nonunion rates were significantly higher in the cage group (5.32%) than in allograft group (1.97%) (P < 0.01). When controlling for confounders, increased rates of nonunion were consistently observed in the cage group, achieving statistical significance in 25 of the 26 analyses.

CONCLUSION

The increased rate of nonunion associated with intervertebral cages may suggest the superiority of allograft over cages in ACDF.

LEVEL OF EVIDENCE

3.

Annular closure device for disc herniation: meta-analysis of clinical outcome and complications

Background

Lumbar intervertebral disc herniation is a common cause of lower back and leg pain, with surgical intervention (e.g. discectomy to remove the herniated disc) recommended after an appropriate period of conservative management, however the existing or increased breach of the annulus fibrosus persists with the potential of reherniation. Several prosthesis and techniques to reduce re-herniation have been proposed including implantation of an annular closure device (ACD) – Barricaid™ and an annular tissue repair system (AR) – Anulex-Xclose™. The aim of this meta-analysis is to assist surgeons determine a potential approach to reduce incidences of recurrent lumbar disc herniation and assess the current devices regarding their outcomes and complications.

Methods

Four electronic full-text databases were systematically searched through September 2017. Data including outcomes of annular closure device/annular repair were extracted. All results were pooled utilising meta-analysis with weighted mean difference and odds ratio as summary statistics.

Results

Four studies met inclusion criteria. Three studies reported the use of Barricaid (ACD) while one study reported the use of Anulex (AR). A total of 24 symptomatic reherniation were reported among 811 discectomies with ACD/AR as compared to 51 out of 645 in the control group (OR: 0.34; 95% CI: 0.20,0.56; I² = 0%; P < 0.0001). Durotomies were lower among the ACD/AR patients with only 3 reported cases compared to 7 in the control group (OR: 0.54; 95% CI: 0.13, 2.23; I² = 11%; P = 0.39). Similar outcomes for post-operative Oswestry Disability Index and visual analogue scale were obtained when both groups were compared.

Conclusion

Early results showed the use of Barricaid and Anulex devices are beneficial for short term outcomes demonstrating reduction in symptomatic disc reherniation with low post-operative complication rates. Long-term studies are required to further investigate the efficacy of such devices.

Effectiveness of an annular closure device in a "real-world" population: stratification of registry data using screening criteria from a randomized controlled trial

Purpose

Increased focus has been put on the use of “‘real-world” data to support randomized clinical trial (RCT) evidence for clinical decision-making. The objective of this study was to assess the performance of an annular closure device (ACD) after stratifying a consecutive series of “real-world” patients by the screening criteria of an ongoing RCT.

Materials and methods

This was a single-center registry analysis of 164 subjects who underwent limited discectomy combined with ACD for symptomatic lumbar disc herniation. Patients were stratified into two groups using the selection criteria of a pivotal RCT on the same device: Trial (met inclusion; n=44) or non-Trial (did not meet inclusion; n=120). Patient-reported outcomes, including Oswestry Disability Index (ODI) and visual analog scale (VAS) for leg and back pain, and adverse events were collected from baseline to last follow-up (mean: Trial – 15.6 months; non-Trial – 14.6 months). Statistical analyses were performed with significance set at p<0.05.

Results

Patient-reported outcomes were not significantly different between groups at last (p≥0.15) and clinical success (≥15-point improvement in ODI score; ≥20-point improvement in VAS scores) was achieved in both the groups. Three non-Trial (2.5%) and three Trial (6.8%) patients experienced symptomatic reherniation (p=0.34). Rates of reoperation, ACD mesh dislocation/separation, and other radiographic findings were similar between groups (p=1.00).

Conclusion

Outcomes with the ACD appeared advantageous in both the groups, particularly in comparison with historical reherniation rates reported in the same high-risk, large annular defect population. Stratification of this “real-world” series on the basis of RCT screening criteria did not result in significant between-group differences. These findings suggest that the efficacy of the ACD extends beyond the strictly defined patient population being studied in the RCT of this device. Furthermore, reducing the reherniation rate following lumbar discectomy has positive clinical and economic implications.