249. A novel posterior total joint replacement for the lumbar spine as an alternative to fusion: pilot data for the first 84 patients

Abstract

BACKGROUND CONTEXT Effective alternatives to degenerative lumbar fusion have remained elusive. Fusion frequently results in adjacent level disease, reoperation, poor outcomes, and high costs. Anterior total disc replacement (TDR) does not address facet pathology or neural compression; thus, indications are limited. There is a need for a posterior-based motion-sparing option that allows for neural decompression, facetectomy, and disc replacement. PURPOSE To present the pilot data for the first 84 patients undergoing posterior lumbar total joint replacement for common degenerative conditions. STUDY DESIGN/SETTING Prospective case series. PATIENT SAMPLE Adult patients (age 18-79 years) with degenerative lumbar pathology were treated. Diagnoses included: degenerative spondylolisthesis, recurrent disc herniation, degenerative disc disease, foraminal stenosis, and central lumbar stenosis. Tumor, trauma, and infection cases were excluded. OUTCOME MEASURES Oswestry Disability Index (ODI), visual analogue scale (VAS) for back and leg pain, and opioid use. METHODS The implant is a motion-sparing lumbar reconstruction that replaces the function of both the disc and facets and is implanted using a bilateral trans-foraminal (TLIF) approach with complete facetectomies. For this IRB-approved pilot study, 84 adult patients (mean age 52.49) with degenerative lumbar pathology were treated. Diagnoses included: degenerative spondylolisthesis, recurrent disc herniation, degenerative disc disease, foraminal stenosis, and central lumbar stenosis. Tumor, trauma, and infection cases were excluded. ODI, VAS for back and leg pain, and opioid use were collected at baseline, 3 months, 6 months, and 1 year, with radiographs obtained at each time point. To date, follow up data is available for 70 patients at 3 months, 54 at 6 months, and 38 patients at 1 year. RESULTS A total of 125 levels were treated: L4-5 (57), L5-S1 (41), L3-4 (22), L2-3 (4), and L1-2 (1). Forty-seven patients had one level, 33 had two levels, and four patients had three levels treated. ODI improved significantly at each time interval following surgery (46.58 preop, 23.91 at 3 months, 18.87 at 6 months, and 13.80 at 1 year). VAS back and leg pain (calculated as the highest reported VAS score multiplied by the frequency of that pain level) also improved at each time point, from an average value of 51.59 at baseline to 17.40 at 3 months, 13.64 at 6 months, and 11.39 at 1 year. Minimal symptom state (ODI ≤ 20 and VAS back and leg pain ≤ 20) was maintained by 18 out of 27 one-level patients (67%), and by 7 out of 10 two-level patients (70%) at 1 year. Opioid usage was CONCLUSIONS Here we present pilot data for the first 84 patients undergoing a novel, posterior-based total joint replacement for the lumbar spine using a TLIF approach with complete facetectomies. The approach allows for wide neural decompression, facetectomy, and complete discectomy, with the implant working to replace the function of the disc and facets to preserve motion. ODI and VAS back/leg pain scores improved significantly at each time interval following surgery. At 1 year, a high percentage (66%) of patients have maintained a minimal symptom state, which is a significant improvement compared with the fusion literature where a recent study reported 18% of 396 patients maintained a minimal symptom state after 1 year following fusion. The greatest theoretical benefit of this device is preservation of lumbar motion segments resulting in more physiologic lumbar motion and the potential to decrease the risk for adjacent segment disease. Ongoing long-term follow-up is underway to evaluate the durability of this procedure and the impact on adjacent segments. FDA DEVICE/DRUG STATUS 3Spine BalancedBack Lumbar Joint Replacement (Investigational/Not approved)