Effectiveness of Minimally Invasive Decompression Alone in L4-5 Degenerative Spondylolisthesis With Translational Motion: Short-term Results in a Preliminary Cohort.

Methods: Retrospective cohort.

Background: Although fusion surgery is the established recommendation for degenerative lumbar spondylolisthesis (DLS) with instability, a decompression alone might be needed in some cases based on the patient's age, comorbidity burden, surgical fitness, and preference.

Objective: To analyze the outcomes of minimally invasive decompression alone in patients with L4-5 DLS and translational motion ≥2 mm and compare with fusion over short term.

Methods: Patients who underwent minimally invasive decompression or fusion for L4-5 DLS with translational motion ≥2 mm and had a minimum of 1-year follow-up (maximum follow-up of 2 y) were included. Postoperative improvement in patient-reported outcome measures (PROMs) was analyzed. The decompression and fusion groups were compared for improvement in PROMs, minimal clinically important difference (MCID), patient acceptable symptom state (PASS), and response on global rating change (GRC) scale.

Results: Eighty-four patients were included, out of which 60 (71.4%) underwent fusion. The decompression group had a significantly higher average age compared with fusion (69.3 vs. 64.8 y, P=0.036). There was no significant difference between the groups in other demographic variables and preoperative PROMs. The decompression group showed significant improvement in PROM postoperatively. The decompression group had a comparable magnitude of improvement in PROMs and MCID and PASS achievement rates as fusion over short term follow-up. More than 80% of patients reported feeling better compared with preoperative at both the timepoints with no significant difference in the responses between the 2 groups.

Conclusions: Minimally invasive decompression alone does lead to significant postoperative improvement over the short term and may be considered as an option in patients with unstable spondylolisthesis where fusion cannot be done. However, these are preliminary results and future research with a larger sample size and longer follow-up is required to further investigate this topic. Methods: Level III.