A novel lumbar total joint replacement may be an improvement over fusion for degenerative lumbar conditions: a comparative analysis of patient-reported outcomes at one year.

BACKGROUND CONTEXT

Effective alternatives to lumbar fusion for degenerative conditions have remained elusive. Anterior total disc replacement does not address facet pathology or central/recess stenosis, resulting in limited indications. A posterior-based motion-preserving option that allows for neural decompression, facetectomy, and reconstruction of the disc and facets may have a role.

PURPOSE

The purpose was to compare one-year patient-reported outcomes for a novel, all-posterior, lumbar total joint replacement (LTJR - replacing both the disc and facet joints) against transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar conditions warranting fusion (degenerative spondylolisthesis, recurrent disc herniation, severe foraminal stenosis requiring facet removal, and adjacent segment degeneration).

STUDY DESIGN/SETTING: A retrospective analysis of prospectively collected data comparing outcomes for LTJR patients to TLIF patients at an academic teaching hospital.

PATIENT SAMPLE

Analysis was conducted on 156 adult TLIF patients who were propensity matched to the 52 LTJR patients for a total sample of 208.

OUTCOME MEASURES

Self-reported Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back and leg pain were compared preoperatively, 3 months and 1 year after surgery.

METHODS

The implant is a motion-preserving lumbar reconstruction that replaces the function of both the disc and facets and is implanted using a bilateral transforaminal approach with complete facetectomies. Adult patients with degenerative lumbar pathology undergoing either LTJR or open TLIF were analyzed. These degenerative conditions included: grade 1 degenerative spondylolisthesis, recurrent disc herniation, adjacent segment disease, disc degeneration with severe foraminal stenosis). Trauma, tumor, grade 2 or higher spondylolisthesis, spinal deformity, and infection cases were excluded. Propensity score matching was performed to ensure parity between the cohorts. Multivariable regression analyses were done to compare the 1-year results as measured by 3 different standards to assess procedure success.

RESULTS

At 3 months, both the LTJR and TLIF cohorts showed significant and similar improvements in ODI and NRS back and leg pain. At 1 year, the LTJR cohort showed continued improvement in ODI and NRS back pain, while the TLIF group showed a plateau for ODI, back and leg pain. In a series of three multivariable logistic regressions, LTJR was shown to provide 3.3 times greater odds of achieving the minimal clinical symptom state in disability and pain (ODI <20%, NRS back and leg pain <2) and 2.4 and 4.1 times greater odds of achieving substantial clinical benefit (18% reduction in ODI) and minimal clinically important difference (30% reduction in ODI) as compared to TLIF.

CONCLUSIONS

Here we present a comparative analysis for the first 52 patients undergoing a novel, posterior-based LTJR for the lumbar spine versus TLIF for degenerative pathology. The approach for the LTJR 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. At 1 year, the LTJR cohort showed significant improvement in ODI and NRS back and leg pain as compared to TLIF. These results suggest that wide neural decompression combined with motion preservation using this novel LTJR may represent a viable alternative to TLIF for treating certain degenerative conditions. A prospective controlled trial is under development to further evaluate the efficacy, safety, and durability of this procedure.