Standalone Bilateral Decompression for Grade One Degenerative Spondylolisthesis Results in Durable Relief of Symptoms and Low Reoperation Rate: A Prospective Trial with 10 Years of Follow Up

Abstract

Study design: A prospective cohort study from 2013-2015 at a single academic medical center.

Objective: The purpose of this study was to assess patient reported outcome measures and long-term reoperation rates in degenerative spondylolisthesis (DS) patients undergoing standalone decompression, and to assess the clinical and radiographic factors associated with reoperation.

Summary of background data: DS is a common spine pathology with a continued treatment dilemma. The common surgical methods include standalone decompression or decompression with fusion; the patient characteristics leading to successful outcomes for either procedure, however, remain unknown.

Methods: Patients were identified with a 1-3 level Grade 1 DS and indicated for a standalone bilateral decompression. Following enrollment, multiple clinical and radiographic parameters were measured. Patients underwent standalone decompression. Clinical data was collected preoperatively and 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. Patients were followed for 10 years.

Results: Forty-six consecutive patients were enrolled in the study. VAS back and leg pain improved by 6 weeks postoperatively and was maintained through 2 years. There were several changes in radiographic measurements following surgery, including increases in mean slippage, mean flexion slippage, mean extension slippage, and mean segmental flexion angle. The mean angular motion decreased. Within 2 years, the cumulative incidence of reoperations after adjusting for the competing risk of death was 8.7% for same level reoperations and 13.0% for any level reoperation. The reoperation rate at 5 and 10 years was 23.9% at the same level and 32.6% at any level, as all reoperations within the cohort occurred within the first 5 years.

Conclusion: Patients who underwent a standalone decompression had improvement in their preoperative symptoms with a low revision rate up to 10 years following surgery. Several factors can result in an increased risk of revision surgery, which can be used to counsel patients.

Keywords: bilateral decompression; decompression; degenerative spondylolisthesis; laminectomy; minimally invasive surgery; spine.