Degenerative Spondylolisthesis: When to Fuse and When Not to? A New Scoring System.

Study Design: A prospective cohort.

Objective: The objective of this study was to develop a scoring system for lumbar degenerative spondylolisthesis (LDS) that would guide decision-making.

Background: The management protocol for LDS has been under debate, with no guidelines. Most studies oversimplify LDS as a homogenous entity.

Materials And Methods: A retrospective analysis of 131 patients who underwent surgery for LDS between July 2007 and October 2011 with a minimum follow-up of 3 years was carried out on the basis of clinical, radiologic, and technical factors. A scoring system was conceptualized. Clinical: back pain score-2, age younger than 70 years-1, high-demand activity-1. Radiologic: segmental kyphosis-1.5, segmental dynamic translation-1, disk height >50% of adjacent level-1, facet effusion-1, sagittal facet-orientation-1. Technical: feasibility to decompress without causing instability-1.5. Its reliability was ascertained by a univariate analysis. The benchmark was set at 5.5 according to the Youden Index. This was followed by a prospective study for reliability analysis between November 2011 and January 2017 of 52 patients who underwent stand-alone decompression in LDS with a minimum follow-up of 24 months. Outcomes were evaluated using the Oswestry Disability Index and the Visual Analog Scale. Interobserver variability was determined. None of the patients in the retrospective or prospective group had undergone any lumbar surgery previously.

Results: The mean Oswestry Disability Index and Visual Analog Scale of both the groups in the retrospective and the stand-alone decompression groups in prospective studies showed significant improvement. The interobserver reliability was high, with a κ value of 0.847.

Conclusions: The proposed scoring system helps view LDS as a heterogenous condition and assists in tailoring treatment for individual patients. For a select subgroup of patients with LDS, minimally invasive decompression (unilateral laminotomy and bilateral decompression using a minimally invasive surgery tubular retractor system) without fusion is adequate.

Level Of Evidence: Level III.