Clinical and Radiological Results of PLIF for Degenerative Spondylolisthesis

Abstract

This is a follow-up study of the surgical efficacy of posterior lumbar interbody fusion (PLIF) for degenerative spondylolisthesis. Over the past 17 years, the authors have applied 7 alternative forms of reinforcement/augmentation to the basic/simple PLIF in an attempt to minimize the rate of fusion complications such as graft collapse, delayed fusion and nonunion. Each variant of the PLIF, along with the basic PLIF was performed on a significant number of patients, yielding a large population for this study. Clinical, radiological and statistical analyses were performed to determine the success of each variant, the basic PLIF, as well as the efficacy of the PLIF in aggregate for cases of degenerative spondylolisthesis. 166 patients were enrolled in this study. The average post-surgical follow-up occurred at 60 months, with a range of 13–188 months encompassing all subjects. Group A (basic/simple PLIF with autologous iliac bone graft)'s rate of fusion complications was 50%. Group B (autologous graft with internal fixation) rate of fusion complications was 36%. Group C (VSP with intervertebral spacers) rate of fusion complications was 13%. The mean recovery rates increased in a stepwise fashion from Group A to B to C. The mean recovery rates in patients with optimal fusion was significantly higher than in patients with fusion complications. The authors conclude that rigid fixation and graft solidarity are essential for achieving optimal results when performing the PLIF. Optimal fusion was correlated with significantly better clinical results.