Risk factors for early reherniation after lumbar discectomy with or without annular closure: results of a multicenter randomized controlled study.

BACKGROUND: Reherniation after lumbar discectomy is classified as a failure and occurs in 3 to 18% of cases. Various risk factors for reherniation such as age, sex, body mass index, smoking, and size of annular defect have been reported. The aim of this study was to identify risk factors for early reherniation after one-level lumbar discectomy with or without annular closure within 3 months after surgery. METHODS: This study is based on data analysis of a prospective, multicenter randomized controlled trial in Europe. Patients included underwent standard lumbar discectomy-with or without implantation of an annular closure device (ACD). Enrollment of 554 patients in 21 centers in Europe (Germany, Switzerland, Austria, Belgium, The Netherlands, and France) started in 2010 and was completed in October 2014. A total of 276 patients were randomized to the ACD group (ACG) and 278 patients to the control group (CG). RESULTS: Four (1.5%) symptomatic reherniations occurred in the ACG and 18 (6.5%) in the CG. In the overall population, a significant correlation was found with recurrent herniation for disc degeneration (Pfirrmann p = 0.009) and a trend for current smoker status (p = 0.07). In CG, age ≥ 50 years (p = 0.05) and disc degeneration (Pfirrmann p = 0.026, Kellgren and Lawrence p = 0.013) were predictive factors for reherniation. CONCLUSION: In the current study, risk factors for early recurrent disc herniation after lumbar discectomy were age ≥ 50 years and moderate disc degeneration. The annular closure device reduced the risk of early reherniation. TRIAL REGISTRATION: Clinicaltrials.gov NCT01283438.

Endplate changes following discectomy: natural history and associations between imaging and clinical data.

PURPOSE: Some patients will experience post-operative back pain following lumbar discectomy, and the potential sources for that pain are poorly understood. One potential source is the vertebral endplates. The goal of this study was to document the changes that occur in lumbar endplates following discectomies, and to assess associations between endplate changes and clinical outcomes. METHODS: Changes in lumbar endplates and discs were assessed from X-rays, CT and MRI exams by comparing preoperative imaging with imaging obtained at yearly intervals up to 5 years. 260 endplates in 137 patients with single-level herniation and discectomy were analyzed. The geometry of osseous defects in the endplates was measured from the CT exams, and marrow and disc changes adjacent to endplates were assessed from the MRI exams. Clinical outcome assessments were collected at each time point. Descriptive statistics were used to describe endplate defect sizes, and logistic regression and analysis of variance were used to identify potential associations between endplate and vertebral body changes and clinical outcomes. RESULTS: Approximately 14 % of the endplates had osseous defects prior to surgery. After surgery, 24 % of inferior and 43 % of superior endplates had defects. Change occurred within the first year and remained relatively constant over the next few years. Disc signal intensity worsened and disc height decreased following surgery. New Modic changes were also observed. None of these changes were associated with having achieved a clinically significant improvement in outcome scores. The follow-up rates were low at the later time points and significant associations cannot be ruled out. CONCLUSIONS: This study documents lesion characteristics in detail and supports that osseous defects in the endplates at the level of a lumbar discectomy may be a relatively common finding following surgery, along with disc height loss, loss of disc signal intensity, and Modic changes. The clinical significance of these imaging findings could not be conclusively determined in this study.

Spinal Arachnoiditis Ossificans: A Case-Based Update.

Arachnoiditis ossificans is a rare disease, characterized by intradural ossifications, representing the end stage of chronic adhesive arachnoiditis. We describe the case of a 55-year-old patient who developed symptoms of a cauda equina syndrome after an open microdiscectomy at the L5 to S1 segment. A subsequent exploratory surgery revealed an intradural concentric bony structure with partly incorporated and partly adherent nerve roots. A partial removal of the intradural calcifications was performed. Postoperatively, the patient showed neurological improvement. The removed intradural calcifications were submitted for histological analysis and proved to be normal bone tissue, notably containing yellow bone marrow. To our knowledge, the presence of yellow bone marrow within bony cavities of arachnoiditis ossificans has not previously been reported.

Effectiveness of an Annular Closure Device to Prevent Recurrent Lumbar Disc Herniation: A Secondary Analysis With 5 Years of Follow-up.

Importance: Patients with large annular defects following lumbar microdiscectomy for disc herniation are at increased risk for symptomatic recurrence and reoperation. Objective: To determine whether a bone-anchored annular closure device in addition to lumbar microdiscectomy resulted in lower reherniation and reoperation rates vs lumbar microdiscectomy alone. Design, Setting, and Participants: This secondary analysis of a multicenter randomized clinical trial reports 5-year follow-up for enrolled patients between December 2010 and October 2014 at 21 clinical sites. Patients in this study had a large annular defect (6-10 mm width) following lumbar microdiscectomy for treatment of lumbar disc herniation. Statistical analysis was performed from November to December 2020. Interventions: Lumbar microdiscectomy with additional bone-anchored annular closure device (device group) or lumbar microdiscectomy only (control group). Main Outcomes and Measures: The incidence of symptomatic reherniation, reoperation, and adverse events as well as changes in leg pain, Oswestry Disability Index, and health-related quality of life when comparing the device and control groups over 5 years of follow-up. Results: Among 554 randomized participants (mean [SD] age: 43 [11] years; 327 [59%] were men), 550 were included in the modified intent-to-treat efficacy population (device group: n = 272; 270 [99%] were White); control group: n = 278; 273 [98%] were White) and 550 were included in the as-treated safety population (device group: n = 267; control group: n = 283). The risk of symptomatic reherniation (18.8% [SE, 2.5%] vs 31.6% [SE, 2.9%]; P < .001) and reoperation (16.0% [SE, 2.3%] vs 22.6% [SE, 2.6%]; P = .03) was lower in the device group. There were 53 reoperations in 40 patients in the device group and 82 reoperations in 58 patients in the control group. Scores for leg pain severity, Oswestry Disability Index, and health-related quality of life significantly improved over 5 years of follow-up with no clinically relevant differences between groups. The frequency of serious adverse events was comparable between the treatment groups. Serious adverse events associated with the device or procedure were less frequent in the device group (12.0% vs 20.5%; difference, -8.5%; 95% CI, -14.6% to -2.3%; P = .008). Conclusions and Relevance: In patients who are at high risk of recurrent herniation following lumbar microdiscectomy owing to a large defect in the annulus fibrosus, this study's findings suggest that annular closure with a bone-anchored implant lowers the risk of symptomatic recurrence and reoperation over 5 years of follow-up. Trial Registration: ClinicalTrials.gov Identifier: NCT01283438.

Challenges in the Analysis of Longitudinal Pain Data: Practical Lessons from a Randomized Trial of Annular Closure in Lumbar Disc Surgery.

Purpose. To analyze leg pain severity data from a randomized controlled trial (RCT) of lumbar disc surgery using integrated approaches that adjust pain scores collected at scheduled follow-up visits for confounding clinical events occurring between visits. Methods. Data were derived from an RCT of a bone-anchored annular closure device (ACD) following lumbar discectomy versus lumbar discectomy alone (Control) in patients with large postsurgical annular defects. Leg pain was recorded on a 0 to 100 scale at 6 weeks, 3 months, 6 months, 1 year, and 2 years of follow-up. Patients with pain reduction ≥20 points relative to baseline were considered responders. Unadjusted analyses utilized pain scores reported at follow-up visits. Since symptomatic reherniation signifies clinical failure of lumbar discectomy, integrated analyses adjusted pain scores following a symptomatic reherniation by baseline observation carried forward for continuous data or classification as nonresponders for categorical data. Results. Among 550 patients (272 ACD, 278 Control), symptomatic reherniation occurred in 10.3% of ACD patients and in 21.9% of controls (p < 0.001) through 2 years. There was no difference in leg pain scores at the 2-year visit between ACD and controls (12 versus 14; p = 0.33) in unadjusted analyses, but statistically significant differences favoring ACD (19 versus 29; p < 0.001) in integrated analyses. Unadjusted nonresponder rates were 6.0% with ACD and 6.7% with controls (p = 0.89), but 15.7% and 27.8% (p = 0.001) in integrated analyses. The probability of nonresponse was 16.4% with ACD and 18.3% with controls (p = 0.51) in unadjusted analysis, and 23.7% and 31.2% (p = 0.04) in integrated analyses. Conclusion. In an RCT of lumbar disc surgery, an integrated analysis of pain severity that adjusted for the confounding effects of clinical failures occurring between follow-up visits resulted in different conclusions compared to an unadjusted analysis of pain scores reported at follow-up visits only.

Reoperation After Primary Lumbar Discectomy with or without Implantation of a Bone-Anchored Annular Closure Device: Surgical Strategies and Clinical Outcomes.

OBJECTIVE: To determine whether presence of a bone-anchored annular closure device (ACD) impacts reoperation strategies and subsequent outcomes. METHODS: Patients with large annular defects after single-level limited lumbar discectomy were randomly allocated to receive an ACD or discectomy alone (controls) and were followed for at least 3 years. RESULTS: Among 550 patients, reoperation risk was lower with ACD (11.0% vs. 19.3%). The types of reoperations and operative time were similar in each group, and the ACD did not interfere with surgical planning or operative technique. Fusion success was 87% with ACD versus 85% for controls. Perioperative complications occurred in 22% and 19% of reoperations, respectively. Leg pain and back function were improved with ACD versus controls after fusion procedures, and no group differences were observed after non-fusion reoperations. CONCLUSIONS: In patients undergoing post-discectomy reoperation, patients with an ACD were treated with similar operative techniques, were not exposed to additional surgical risks, and reported comparable clinical outcomes versus those without an ACD.

Annular closure in lumbar microdiscectomy for prevention of reherniation: a randomized clinical trial.

BACKGROUND CONTEXT: Patients with large annular defects after lumbar discectomy for disc herniation are at high risk of symptomatic recurrence and reoperation. PURPOSE: The present study aimed to determine whether a bone-anchored annular closure device, in addition to lumbar microdiscectomy, resulted in lower reherniation and reoperation rates plus increased overall success compared with lumbar microdiscectomy alone. DESIGN: This is a multicenter, randomized superiority study. PATIENT SAMPLE: Patients with symptoms of lumbar disc herniation for at least 6 weeks with a large annular defect (6-10 mm width) after lumbar microdiscectomy were included in the study. OUTCOME MEASURES: The co-primary end points determined a priori were recurrent herniation and a composite end point consisting of patient-reported, radiographic, and clinical outcomes. Study success required superiority of annular closure on both end points at 2-year follow-up. METHODS: Patients received lumbar microdiscectomy with additional bone-anchored annular closure device (n=276 participants) or lumbar microdiscectomy only (control; n=278 participants). This research was supported by Intrinsic Therapeutics. Two authors received study-specific support morethan $10,000 per year, 8 authors received study-specific support less than $10,000 per year, and 11 authors received no study-specific support. RESULTS: Among 554 randomized participants, 550 (annular closure device: n=272; control: n=278) were included in the modified intent-to-treat efficacy analysis and 550 (annular closure device: n=267; control: n=283) were included in the as-treated safety analysis. Both co-primary end points of the study were met, with recurrent herniation (50% vs. 70%, P<.001) and composite end point success (27% vs. 18%, P=.02) favoring annular closure device. The frequency of symptomatic reherniation was lower with annular closure device (12% vs. 25%, P<.001). There were 29 reoperations in 24 patients in the annular closure device group and 61 reoperations in 45 control patients. The frequency of reoperations to address recurrent herniation was 5% with annular closure device and 13% in controls (P=.001). End plate changes were more prevalent in the annular closure device group (84% vs. 30%, P<.001). Scores for back pain, leg pain, Oswestry Disability Index, and health-related quality of life at regular visits were comparable between groups over 2-year follow-up. CONCLUSIONS: In patients at high risk of herniation recurrence after lumbar microdiscectomy, annular closure with a bone-anchored implant lowers the risk of symptomatic recurrence and reoperation. Additional study to determine outcomes beyond 2 years with a bone-anchored annular closure device is warranted.

Protecting facet joints post-lumbar discectomy: Barricaid annular closure device reduces risk of facet degeneration.

Lumbar discectomy is an effective treatment for lumbar disc herniation (LDH). Although the majority of patients experience successful outcomes, a significant fraction will experience a recurrence of their back pain due to facet joint degeneration. Facet joint degeneration after discectomy may be the result of excessive nuclear removal, disc space narrowing, and annular injury. This study investigated whether implantation with the Barricaid annular closure device (ACD) during discectomy reduced the rate of facet degeneration. Inclusion criteria were primary lumbar disc herniation failing conservative treatment, Visual Analog Scale (VAS) Leg≥40/100, Oswestry Disability Index (ODI)≥40/100 and defects that were ≤60 mm2 (Barricaid arm only), and patient age 18-75. CT interpretations were collected preoperatively and 12 months post-discectomy. Patients implanted with Barricaid had significantly reduced rates and grades of facet degeneration than patients without Barricaid. Reinforcing the annulus fibrosus with Barricaid during lumbar discectomy may slow the progression of facet joint degeneration.

A prospective cohort study of close interval computed tomography and magnetic resonance imaging after primary lumbar discectomy: factors associated with recurrent disc herniation and disc height loss.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: We performed a prospective cohort study with standardized postoperative lumbar imaging every 3 months for a year then annually to assess the incidence and factors associated with same-level recurrent disc herniation. SUMMARY OF BACKGROUND DATA: The true incidence of same-level recurrent disc herniation after lumbar discectomy is unclear. Retrospective studies have reported widely varying incidences between 3% and 18%. Prospective controlled studies are lacking. METHODS: A total of 108 patients undergoing first-time lumbar discectomy for refractory radiculopathy were enrolled. Baseline lumbar CT and MRI and standardized clinical data were assessed before surgery, and CT and MRI scans repeated 6 weeks, 3, 6, 9, 12, and 24-months after surgery and at the time of recurrent sciatica. Age, weight, preoperative disc volume, and height, volume of disc removed, and size of anular defect were compared with postoperative disc height loss and recurrent disc herniation using regression analysis. RESULTS: One hundred patients (41 +/- 10 years old) were available for 1-year (93%) and 76 (70%) for 2-year follow-up (mean follow-up: 25 +/- 12 months). Improvement in all outcome measures was observed by 6 weeks after surgery (P < 0.005). An 18% loss of disc height was observed 3 months after surgery, progressing to 26% by 2 years. Eleven (10.2%) patients experienced recurrent disc herniation requiring revision discectomy a mean 10.5 months after surgery. Subjects with larger anular defects (P = 0.019) and with smaller percentage of disc volume removed (P = 0.028) were associated with an increased risk of recurrent disc herniation. Conversely, those from whom greater disc volumes were removed (P = 0.024) had more progressive disc height loss by 6 months after surgery. CONCLUSION: Larger anular defects and less disc removal increased the risk of reherniation. Greater volumes of disc removal were associated with accelerated disc height loss. In the setting of larger anular defects or less aggressive disc removal, concern for recurrent herniation should be increased during outpatient follow-up. In this situation effective anular repair may be helpful.