Segmental Lordosis Gain Is a Prognostic Radiological Factor of Good Functional Outcome After the Implantation of a Single-Level Prosthesis or a Hybrid Construct for Lumbar Disc Degeneration.

Abstract

To identify radiological factors and functional outcomes associated with good results after implantation of a single lumbar disc prosthesis or a hybrid construct (anterior lumbar interbody fusion and lumbar disc prosthesis) in the setting of painful degenerative lumbar discopathy. This single-center, retrospective 10-year study included 92 patients ˃18 years old with chronic low back pain evolving for at least 1 year. The patients had degenerative disc disease and had failed conservative treatment and underwent lumbar arthroplasty. Radiographic and clinical outcomes were assessed preoperatively and 1 year after surgery. Functional evaluation was based on the Oswestry Disability Index (ODI) and a numerical rating scale. Radiological analysis was based on lumbar x-rays and magnetic resonance imaging parameters. Patients were assigned to 2 groups according to the reduction in ODI score (>15 points or <15 points), and statistical analysis was done in both groups to find predictive radiological factors for a satisfactory functional outcome. Clinically, 60 patients (65.2%) had a satisfactory functional result and 32 patients (34.8%) had a poor outcome according to ODI score. Radiographically, gain in segmental lordosis was statistically associated with good functional outcomes (8.9° for ODI decrease >15 vs. 3.2° for ODI decrease <15). This study determined that gain in segmental lordosis is associated with a satisfactory functional outcome after a single-level lumbar disc prosthesis or a hybrid construct. Our study demonstrates that segmental lordosis gain may represent a significative useful positive predictor factor of patient outcome.