Characterizing Spinal Decompression for Foot Drop Caused by Lumbar Degenerative Disease: A Systematic Review and Meta-Analysis of Cohorts

Background/Objectives: There exists a need to capture the current landscape of the literature for lumbar decompression on muscle strength, as measured by manual muscle testing (MMT), in cohorts with foot drop secondary to lumbar degenerative disease (LDD). Methods: A literature search of PubMed, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Scopus, and Web of Science was conducted from each database's inception to 21 March 2025. Eligible studies reported patients with LDD-related foot drop treated surgically. This review was registered in PROSPERO (ID: CRD42024550980). Results: A total of 20 studies comprising 918 patients met the eligibility criteria, with most cases attributable to lumbar disc herniation (79% of patients, 95% CI: 0.72-0.85, I² = 96%) or spinal stenosis (22% of patients, 95% CI: 0.15-0.30, I² = 96%). Following surgery, 60% of patients (95% CI: 0.44-0.75, I² = 97%) achieved an MMT score of 4-5, indicating recovery, while 82% (95% CI: 0.76-0.88, I² = 89%) demonstrated an improvement of at least one MMT grade. No improvement was seen in 18% of patients (95% CI: 0.12-0.24, I² = 89%). For pain, the preoperative VAS mean was 5.91 (95% CI: 4.21-7.60, I² = 99%), while the postoperative mean was 1.00 (95% CI: -0.05-2.06, I² = 99%). Overall complications were reported at 1% (95% CI: -0.00-0.02, I² = 0%). Conclusions: Lumbar decompression achieves clinically meaningful recovery of LDD-induced foot drop. However, this meta-analysis highlights the overlooked portion of patients who will not respond, providing a sequential approach for future investigation of these cohorts through foundational evidence of the present literature base.