81. Seven-year results of a randomized controlled IDE trial for lumbar artificial discs in single-level degenerative disc

Abstract

BACKGROUND CONTEXT The activL artificial disc received Food and Drug Administration approval in 2015 based on 2-year follow-up data. PURPOSE To compare the 7-year safety and efficacy of the activL® artificial disc with ProDisc-L total disc replacement (TDR) in the treatment of patients with symptomatic single-level lumbar degenerative disc disease (DDD). Study Design/Setting Prospective, randomized, multicenter IDE. Patient Sample A total of 206 patients who underwent single-level lumbar arthroplasty with either Activ L or Prodisc L. OUTCOME MEASURES ODI, SF-36, VAS, complications, re-operations. METHODS Eligible patients presented with symptomatic, single-level, lumbar DDD who failed ≥6 months of nonsurgical management. At entry, 283 patients were randomly allocated to treatment with activL (n=218) or ProDisc-L (n=65) TDR. At 7-years follow-up, a total of 206 patients (activL: 160, ProDisc-L: 46) were available for analysis. RESULTS The activL group was non-inferior compared to the ProDisc-L group in the primary composite end point at 7 years (p=0.0369). Relative to baseline, significant reductions in visual analog scale (VAS) back/leg pain severity as well as improvements in Oswestry Disability Index (ODI) and SF36 Questionnaire were observed in both treatment groups at 7 years. The activL group showed significantly better range of motion for flexion-extension (FE) rotation, disc height/angle and higher proportion of patients without heterotopic ossification, compared with ProDisc-L. Freedom from a serious adverse event through 7 years was 62% in activL patients and 43% in ProDisc-L patients (log-rank p=0.011). Significant reduction in narcotic usage compared to baseline were observed in both treatment groups over time, with 0% of TDR patients using narcotics at 7 years. Freedom from reoperation was high for TDR patients at 95%. Patients who experienced improvements in radiographic (FE rotation, FE translation, lateral rotation), VAS leg pain, ODI, and SF36 measures at 2 years were more likely to experience improvements at 7 years. CONCLUSIONS Long-term evidence supports TDR as safe and efficacious treatment for lumbar DDD. The results demonstrated short-term benefits of TDR are maintained at 7 years, with patients no longer requiring narcotic use. The next generation activL Artificial Disc is more effective at preserving range of motion compared to first generation TDR (ProDisc-L) and offers an improved safety profile. Other primary and secondary outcomes are similar between disc designs. FDA DEVICE/DRUG STATUS Activ L (Approved for this indication), Prods L (Approved for this indication)