Posterior lumbar facet arthroplasty versus fusion for the treatment of spondylolisthesis: 3-year results from the Total Posterior Spine System investigational device exemption study
OBJECTIVE The optimal surgical treatment for lumbar spinal stenosis (LSS) with degenerative spondylolisthesis (DS) remains controversial. Posterior lumbar facet arthroplasty preserves motion after decompression and may address some of the limitations of fusion techniques. The Total Posterior Spine System (TOPS) investigational device exemption trial compared decompression with facet arthroplasty to decompression plus fusion (open with interbody). This study reports the 3-year outcomes from this trial. METHODS This randomized, controlled, multicenter trial enrolled 321 patients with LSS and grade I DS across 37 sites (2:1 randomization of arthroplasty to fusion). Eligible patients were 35–80 years old, had failed ≥ 6 months of nonsurgical treatment, and met thresholds for disability and leg pain. The primary endpoint was a composite clinical success score at 36 months, defined by four criteria: 1) no reoperation or lumbar injection, 2) no major device adverse events, 3) ≥ 15-point improvement in the Oswestry Disability Index (ODI), and 4) no new/progressive neurological deficit. Secondary outcomes included the ODI score, visual analog scale (VAS) scores for back and leg pain, the Zurich Claudication Questionnaire (ZCQ), device-related adverse events, and reoperations. RESULTS One hundred seventy-nine patients in the arthroplasty (TOPS) group and 74 in the fusion group were eligible for the 36-month analysis. The composite clinical success achievement rate was significantly higher in the arthroplasty group (76.0%) than in the fusion group (56.8%; p = 0.0038). The rate of reoperation or lumbar injection was significantly lower for the arthroplasty group (14.0%) compared to the fusion group (25.3%; p = 0.0222). Arthroplasty was associated with a significantly higher minimal clinically important difference (MCID) achievement rate for VAS back pain score compared with fusion (85.2% vs 72.2%; p = 0.041). Although there was no significant difference in ODI score, VAS leg pain score, or ZCQ component scores between groups, the arthroplasty group trended toward higher MCID achievement rates across all patient-reported outcome measures. There was no significant difference in reoperation failure rates between groups (5.8% for arthroplasty vs 9.5% for fusion; p = 0.329). CONCLUSIONS Decompression and dynamic stabilization with lumbar facet arthroplasty was associated with statistically significantly superior clinical outcomes and lower rates of secondary invasive procedures, including reoperations and injections, compared with decompression and fusion. Long-term follow-up is critical in defining the role of lumbar facet arthroplasty for the treatment of DS.
Five-Year Outcomes from Deep Brain Stimulation of the Subthalamic Nucleus for Parkinson Disease
Importance The Implantable Neurostimulator for the Treatment of Parkinson’s Disease (INTREPID) trial was a randomized, double-blind, sham-controlled study of subthalamic nucleus (STN) deep brain stimulation (DBS) for the treatment of Parkinson disease (PD). Objective To evaluate the long-term (5-year) outcomes and safety of STN-DBS for PD. Design, Setting, and Participants This was a prospective, randomized (3:1), 12-week double-blind sham-controlled study at 23 movement disorder centers across the US with an open-label 5-year follow-up. Patients were implanted and followed up with the Vercise DBS system from May 2013 to December 2022. Eligibility required diagnosis of bilateral idiopathic PD with more than 5 years of motor symptoms, more than 6 hours per day of poor motor function, modified Hoehn and Yahr Scale scores higher than 2, Unified Parkinson’s Disease Rating Scale (UPDRS-III) score of 30 or higher (medication-off state), and 33% or higher improvement in UPDRS-III medication-on score. Intervention Bilateral STN-DBS for moderate to advanced PD. Main Outcomes and Measures Primary outcomes included changes in UPDRS and dyskinesia scores, quality-of-life measures, and safety assessments. Exploratory analyses included medication reduction and DBS association with motor signs. Results A total of 313 patients were enrolled with 191 receiving the DBS system, and 137 participants (72%) completed the study. The study population had a mean (SD) age of 60 (7.9) years, with 139 (73%) male participants. Motor function without medication as measured by UPDRS-III improved from a mean (SD) of 42.8 (9.4) to 21.1 (10.6) at year 1 (51%; 95% CI, 49%-53%; P < .001) and 27.6 (11.6) at year 5 (36%; 95% CI, 33%-38%; P < .001). Activities of daily living without medication as measured by UPDRS-II improved from a mean (SD) of 20.6 (6.0) to 12.4 (6.1) at year 1 (41%; 95% CI, 38%-42%; P < .001) and 16.4 (6.5) at year 5 (22%; 95% CI, 18%-23%; P < .001). Dyskinesia scores decreased from 4.0 (5.1) to 1.0 (2.1) at year 1 (75%; 95% CI, 73%-75%; P < .001) and to 1.2 (2.1) at year 5 (70%; 95% CI, 63%-75%; P < .001). The levodopa equivalent dose was reduced by 28% at year 1, remaining stable at year 5 (28%; 95% CI, 26%-31%; P < .001). The most common serious adverse event was infection (9 participants). Ten deaths were reported, none related to the study. Conclusions and Relevance Although STN-DBS outcomes declined slightly, possibly due to the progressive nature of the disease, patients with PD sustained significant improvement in motor and activities of daily living scores, along with a stable reduction in anti-parkinsonian medication over the 5-year follow-up period.
Lumbar Facet Arthroplasty Versus Fusion for Grade-I Degenerative Spondylolisthesis with Stenosis
Background: The comparative effectiveness of decompression plus lumbar facet arthroplasty versus decompression plus instrumented lumbar spinal fusion in patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis is unknown. Methods: In this randomized, controlled, Food and Drug Administration Investigational Device Exemption trial, we assigned patients who had single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis to undergo decompression plus lumbar facet arthroplasty (arthroplasty group) or decompression plus fusion (fusion group). The primary outcome was a predetermined composite clinical success score. Secondary outcomes included the Oswestry Disability Index (ODI), visual analog scale (VAS) back and leg pain, Zurich Claudication Questionnaire (ZCQ), Short Form (SF)-12, radiographic parameters, surgical variables, and complications. Results: A total of 321 adult patients were randomized in a 2:1 fashion, with 219 patients assigned to undergo facet arthroplasty and 102 patients assigned to undergo fusion. Of these, 113 patients (51.6%) in the arthroplasty group and 47 (46.1%) in the fusion group who had either reached 24 months of postoperative follow-up or were deemed early clinical failures were included in the primary outcome analysis. The arthroplasty group had a higher proportion of patients who achieved composite clinical success than did the fusion group (73.5% versus 25.5%; p < 0.001), equating to a between-group difference of 47.9% (95% confidence interval, 33.0% to 62.8%). The arthroplasty group outperformed the fusion group in most patient-reported outcome measures (including the ODI, VAS back pain, and all ZCQ component scores) at 24 months postoperatively. There were no significant differences between groups in surgical variables or complications, except that the fusion group had a higher rate of developing symptomatic adjacent segment degeneration. Conclusions: Among patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis, lumbar facet arthroplasty was associated with a higher rate of composite clinical success than fusion was at 24 months postoperatively. Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.
A Prospective Study of Lumbar Facet Arthroplasty in the Treatment of Degenerative Spondylolisthesis and Stenosis
Study Design: Prospective randomized Food and Drug Administration investigational device exemption clinical trial. Objective: The purpose of the present study is to report the 1-year clinical and radiographic outcomes and safety profile of patients who underwent lumbar facet arthroplasty through implantation of the Total Posterior Spine System (TOPS) device. Summary of Background Data: Lumbar facet arthroplasty is one proposed method of dynamic stabilization to treat grade-1 spondylolisthesis with stenosis; however, there are currently no Food and Drug Administration-approved devices for facet arthroplasty. Methods: Standard demographic information was collected for each patient. Radiographic parameters and patient-reported outcome measures were assessed preoperatively and at regular postoperative intervals. Complication and reoperation data were also collected for each patient. Results: At the time of this study, 153 patients had undergone implantation of the TOPS device. The mean surgical time was 187.8 minutes and the mean estimated blood loss was 205.7cc. The mean length of hospital stay was 3.0 days. Mean Oswestry Disability Index, Visual Analog Score leg and back, and Zurich Claudication Questionnaire scores improved significantly at all postoperative time points (P>0.001). There were no clinically significant changes in radiographic parameters, and all operative segments remained mobile at 1-year follow-up. Postoperative complications occurred in 11 patients out of the 153 patients (7.2%) who underwent implantation of the TOPS device. Nine patients (5.9%) underwent a total of 13 reoperations, 1 (0.6%) of which was for device-related failure owing to bilateral L5 pedicle screw loosening. Conclusions: Lumbar facet arthroplasty with the TOPS device demonstrated a statistically significant improvement in all patient-reported outcome measures and the ability to maintain motion at the index level while limiting sagittal translation with a low complication rate.
Prospective, randomized controlled multicenter study of posterior lumbar facet arthroplasty for the treatment of spondylolisthesis
OBJECTIVE The purpose of this study was to evaluate the safety and efficacy of a posterior facet replacement device, the Total Posterior Spine (TOPS) System, for the treatment of one-level symptomatic lumbar stenosis with grade I degenerative spondylolisthesis. Posterior lumbar arthroplasty with facet replacement is a motion-preserving alternative to lumbar decompression and fusion. The authors report the preliminary results from the TOPS FDA investigational device exemption (IDE) trial. METHODS The study was a prospective, randomized controlled FDA IDE trial comparing the investigational TOPS device with transforaminal lumbar interbody fusion (TLIF) and pedicle screw fixation. The minimum follow-up duration was 24 months. Validated patient-reported outcome measures included the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. The primary outcome was a composite measure of clinical success: 1) no reoperations, 2) no device breakage, 3) ODI reduction of ≥ 15 points, and 4) no new or worsening neurological deficit. Patients were considered a clinical success only if they met all four measures. Radiographic assessments were made by an independent core laboratory. RESULTS A total of 249 patients were evaluated (n = 170 in the TOPS group and n = 79 in the TLIF group). There were no statistically significant differences between implanted levels (L4–5: TOPS, 95% and TLIF, 95%) or blood loss. The overall composite measure for clinical success was statistically significantly higher in the TOPS group (85%) compared with the TLIF group (64%) (p = 0.0138). The percentage of patients reporting a minimum 15-point improvement in ODI showed a statistically significant difference (p = 0.037) favoring TOPS (93%) over TLIF (81%). There was no statistically significant difference between groups in the percentage of patients reporting a minimum 20-point improvement on VAS back pain (TOPS, 87%; TLIF, 64%) and leg pain (TOPS, 90%; TLIF, 88%) scores. The rate of surgical reintervention for facet replacement in the TOPS group (5.9%) was lower than the TLIF group (8.8%). The TOPS cohort demonstrated maintenance of flexion/extension range of motion from preoperatively (3.85°) to 24 months (3.86°). CONCLUSIONS This study demonstrates that posterior lumbar decompression and dynamic stabilization with the TOPS device is safe and efficacious in the treatment of lumbar stenosis with degenerative spondylolisthesis. Additionally, decompression and dynamic stabilization with the TOPS device maintains segmental motion.