For a prospective cohort study, researchers compared mid-to-long-term patient-reported outcome measures (PROMs) for symptomatic degenerative disc disease between single-level total disc arthroplasty (TDA), multi-level TDA, and hybrid constructs (combination of TDA and anterior lumbar interbody fusion [ALIF] across multiple levels) degenerative disk disease (DDD). TDA had shown to be effective in the treatment of single-level DDD. However, there was still a scarcity of published evidence on long-term results for multi-level TDA and hybrid constructs in the treatment of multi-level DDD, as well as long-term comparisons between single-level and multi-level DDD treatment. A total of 950 patients underwent surgery for single-level or multi-level DDD between July 1998 and February 2012 with single-level TDA (n=211), multi-level TDA (n=122), or hybrid construct (n=617). Visual Analog Score for the back (VAS-B) and leg (VAS-L) were recorded, along with the Oswestry Disability Index (ODI) and Roland Morris Disability Questionnaire (RMDQ).
All PROMs in all groups demonstrated statistically and clinically significant improvements in pain and function (P<0.005), which were well above the appropriate minimum clinically important difference (MCID) and exceed literature thresholds for substantial clinical benefit (SCB). Up to an 8-year follow-up, the unadjusted analysis revealed no statistically significant differences in change ratings between the surgery groups for VAS back and leg pain and RMDQ. Adjusted analyses showed the ODI improvement score for the single group was 2.2 points better (95% CI: 0.6–3.9, P=0.009) than in the hybrid group. The RMDQ change score was better in the hybrid group than in the multi-level group by 1.1 points (95% CI: 0.4–1.9, P=0.003) at 6 months and a further 0.4 point at 2 years (95% CI: 0.1–0.8, P=0.011).
When treating symptomatic DDD with single-level TDA, multi-level TDA, and hybrid constructs in the context of rigorous preoperative evaluation in order to obtain a precision diagnosis, clinically and statistically similar results can be attained. These findings hold up over the course of a mid-to-long-term follow-up.