A Prospective Study of Lumbar Facet Arthroplasty in the Treatment of Degenerative Spondylolisthesis and Stenosis: Results from the Total Posterior Spine System (TOPS) IDE Study.

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.

Success Using Neuromodulation With BURST (SUNBURST) Study: Results From a Prospective, Randomized Controlled Trial Using a Novel Burst Waveform.

OBJECTIVE: The purpose of the multicenter, randomized, unblinded, crossover Success Using Neuromodulation with BURST (SUNBURST) study was to determine the safety and efficacy of a device delivering both traditional tonic stimulation and burst stimulation to patients with chronic pain of the trunk and/or limbs. METHODS: Following a successful tonic trial, 100 subjects were randomized to receive one stimulation mode for the first 12 weeks, and then the other stimulation mode for the next 12 weeks. The primary endpoint assessed the noninferiority of the within-subject difference between tonic and burst for the mean daily overall VAS score. An intention-to-treat analysis was conducted using data at the 12- and 24-week visits. Subjects then used the stimulation mode of their choice and were followed for one year. Descriptive statistics were used analyze additional endpoints and to characterize the safety profile of the device. RESULTS: The SUNBURST study demonstrated that burst stimulation is noninferior to tonic stimulation (p < 0.001). Superiority of burst was also achieved (p < 0.017). Significantly more subjects (70.8%) preferred burst stimulation over tonic stimulation (p < 0.001). Preference was sustained through one year: 68.2% of subjects preferred burst stimulation, 23.9% of subjects preferred tonic, and 8.0% of subjects had no preference. No unanticipated adverse events were reported and the safety profile was similar to other spinal cord stimulation studies. CONCLUSIONS: The SUNBURST study demonstrated that burst spinal cord stimulation is safe and effective. Burst stimulation was not only noninferior but also superior to tonic stimulation for the treatment of chronic pain. A multimodal stimulation device has advantages.

Spinal Cord Stimulation Provides Pain Relief with Improved Psychosocial Function: Results from EMP3OWER.

OBJECTIVE: The EMP3OWER™ study evaluated spinal cord stimulation (SCS) safety and efficacy and the associated changes in psychosocial and functional outcomes. METHODS: Upon informed consent and IRB approval, 620 eligible subjects were enrolled prior to SCS trial evaluation and were assessed at baseline, 3, 6 and 12 months post-implant. Patient-reported pain relief (PRP), numerical rating scale (NRS), satisfaction, quality of life (QOL), and pain disability index (PDI) were assessed at all follow-up visits while the pain catastrophizing scale (PCS), short form-36 (SF-36), short form-McGill pain questionnaire version 2 (SF-MPQ-2), and the state-trait anxiety inventory (STAI) were assessed at the 6- and 12-month follow-up visits. Device and/or procedure-related adverse events were also recorded and reported. Subjects reporting a PRP ≥ 50% were considered responders. Repeated measures analysis of variance (RMANOVA) examined the changes across time for all continuous measures. RESULTS: A total of 401 (71%) subjects received a permanent implant. Mean (±SD) patient-reported pain relief was 59.3% (±26.2), 59.2% (±28.9), and 58.2% (±32.0) at 3, 6, and 12 months, respectively. A majority of enrolled subjects were responders at 3 (75.5%), 6 (74.7%), and 12 months (69.7%). RMANOVA revealed a statistically significant change for NRS, PCS, PDI, SF-36, SF-MPQ-2, and STAI scores. At 3 months, the majority of subjects (85.7%) were either very satisfied or satisfied with their device, with similar results at 6 and 12 months. At 3 months, the majority of subjects (73.3%) reported greatly improved or improved QOL with similar results at 6 and 12 months. CONCLUSIONS: Spinal cord stimulation provided pain relief and significant improvement of patient psychological and functional outcome measures.