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.

Object Total disc replacement is an alternative to lumbar fusion, but patients with spinal stenosis, spondylolisthesis, and facet arthropathy are often excluded from this procedure because increased adjacent-segment motion can exacerbate dorsal spondylotic changes. In such cases of degenerative spondylolisthesis with stenosis, decompression and fusion remain the gold standard of treatment. To avoid attendant loss of motion at the treated segment, the TOPS system is a novel total posterior arthroplasty prosthesis that allows for an alternative dynamic, multiaxial, three-column stabilization and motion preservation. The purpose of this study is to report preliminary surgical data and clinical outcomes in patients treated with the TOPS lumbar total posterior arthroplasty system. Methods Twenty-nine patients were enrolled in a nonrandomized, multicenter, prospective pilot study outside the US. All patients had spinal stenosis and/or spondylolisthesis at L4–5 due to facet arthropathy. Radiographs and scores on outcome measures including the visual analog scale (VAS) for pain, Oswestry Disability Index (ODI), Short Form-36, and Zurich Claudication Questionnaire were prospectively recorded before surgery and at 6-week, 3-month, 6-month, and 1-year intervals after surgery. Prior to instrumentation, a bilateral total facetectomy and laminectomy at L4–5 or L3–4 was performed via a standard midline posterior approach. After decompression, the TOPS screws were inserted into four pedicles to achieve maximal purchase with triangulating bicortical trajectories. An appropriately sized TOPS arthroplasty implant was then applied. The mean surgical time was 3.1 hours, and patients' clinical status improved significantly following treatment with the TOPS device. The mean ODI score decreased compared with baseline by 41% at 1 year, and the 100-mm VAS score declined by 76 mm over the same time period. Radiographic analysis showed that lumbar motion was maintained, disc height was preserved, and no evidence of screw loosening was found. No device malfunctions or migrations and no device-related adverse events were reported during the study. Conclusions The TOPS total posterior arthroplasty system represents a novel, dynamic, posterior arthroplasty device that provides multiaxial stability in flexion, extension, rotation, and lateral bending after total facetectomy and neural decompression. The surgical data indicate that it can be safely applied via a traditional approach with low surgical morbidity and excellent 1-year functional and radiographic outcomes in patients with degenerative spondylolisthesis accompanied by stenosis and back pain.

<p class="abstract"><strong>Background:</strong> Same-level reherniation and progressive degeneration with disc height loss are main causes of poor outcome after discectomy and may necessitate reoperation.  A novel prosthesis for anular closure was developed to address these causes.</p><p class="abstract"><strong>Methods:</strong> The design of a multicenter, prospective, randomized, post-market superiority trial comparing limited lumbar discectomy augmented with this device (intervention group) with limited lumbar discectomy alone (control group) is presented.</p><p class="abstract"><strong>Results:</strong> Patients with single-level (L1-S1) posterior or posterolateral disc herniation and radiologic confirmation of neural compression for whom at least six weeks of conservative treatment has failed are eligible.  Patients must have posterior disc height ≥5 mm at index level and baseline Oswestry and VAS leg pain scores of ≥40/100.  Intraoperatively, subjects meeting anular defect size criteria post-discectomy (4-6 mm tall and 6-10 mm wide) will be randomized to study groups in a 1:1 ratio using centralized, web-based software. A Bayesian statistical approach will be used to enroll 400 to 800 subjects who will be followed for at least 24 months.  Two co-primary endpoints will be assessed at 24 months: 1) a composite of leg pain, clinical function, disc height maintenance, and absence of reherniation, reoperation, and device failure; and 2) absence of reherniation based upon independent radiologic analysis.  </p><strong>Conclusions:</strong> This type of analysis is becoming increasingly important as governments and health insurers continue to be pressured to spend limited healthcare funding wisely.

Background:The purposes of the present study were to (1) confirm the risk of recurrent lumbar disc herniation in patients with a large anular defect who had undergone limited discectomy and (2) assess potential risk factors within this population.Methods:The patient population was extracted from the control cohort of a prospective, randomized, multicenter controlled trial investigating the efficacy of an anular closure device following standard limited discectomy. All control patients underwent limited discectomy for the treatment of a single-level symptomatic posterior or posterolateral lumbar disc herniation. Only patients presenting with a large anular defect (6 to 10 mm wide by 4 to 6 mm long) were included in the study (n = 278). Baseline demographic, clinical, and surgical characteristics were recorded. Follow-up evaluations were performed at 6 weeks and at 3, 6, 12, and 24 months. Imaging modalities included magnetic resonance imaging, low-dose computed tomography, and radiographs. Symptomatic recurrent lumbar disc herniation was defined as any symptomatic postoperative herniation on either side of the index level. A multivariate logistic regression analysis of demographic and surgical variables associated with the incidence of recurrent lumbar disc herniation was performed.Results:The mean anular defect area (and standard deviation) was 39.3 ± 9.1 mm2, and the mean excised nuclear tissue volume was 1.3 ± 0.8 mL. At 2 years, the incidence of symptomatic recurrent lumbar disc herniation was 25.3% (64 of 253), with the herniation occurring at a mean of 264 days after the index procedure. Of the 64 patients with recurrent lumbar disc herniation, 36 underwent a subsequent surgical procedure. Logistic regression analysis identified an increased risk for recurrent lumbar disc herniation in females (odds ratio, 2.2) and in patients with greater anular defect widths (odds ratio, 1.3). Furthermore, multivariate logistic regression analyses revealed a significant interaction between age and sex (p = 0.005).Conclusions:The outcomes of the present study provide the most substantial evidence to date in confirming previous reports of a high risk of reherniation among patients with large anular defects. Among those with large anular defects (width, ≥6 mm), females ≤50 years of age had the highest risk (up to ∼10 times higher) of recurrent lumbar disc herniation. It is recommended that an anular repair or closure should be performed after limited discectomies in patients with large anular defects.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Key Points Question In patients at high risk for lumbar disc reherniation owing to a large annular defect following lumbar microdiscectomy, does implantation with an annular closure device reduce the risk of reherniation and reoperation? Findings In this secondary analysis of a randomized clinical trial of 554 patients with large annular defects following lumbar microdiscectomy for symptomatic lumbar disc herniation, the addition of an annular closure device statistically significantly reduced the risk of symptomatic reherniation (18.8% vs 31.6%) and reoperation (16.0% vs 22.6%) through 5 years follow-up with no statistical difference in the risk of serious adverse events. Meaning These findings suggest that the use of an annular closure device may reduce the risk of symptomatic reherniation and reoperation in patients with large annular defects following lumbar microdiscectomy.