Impact of Drop Foot Recovery on Patient-Reported Outcomes following Surgery for Lumbar Degenerative Disease.

Introduction: In patients with lumbar degenerative diseases (LDDs) presenting with drop foot, surgical outcomes have traditionally been assessed by neurological recovery, while studies using patient-reported outcomes (PROs) have been limited. This study retrospectively investigated whether recovery of drop foot influences improvements in PROs following surgery for LDDs. Methods: We retrospectively analyzed 54 surgically-treated patients with LDDs presenting with drop foot, with a minimum follow-up of 1 year. PROs were evaluated using the visual analog scale, the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), the Zurich Claudication Questionnaire, and the Roland-Morris Disability Questionnaire (RMDQ). Results: Patients were divided into recovered (R, manual muscle test [MMT] ≥3) and unrecovered (U, MMT <3) groups. Demographics, etiology, and responsible roots were comparable. The R group had a higher proportion with a preoperative tibialis anterior (TA) MMT score of 2 (64.3% vs. 34.6%, p=0.029) and a shorter paralysis duration (31.7 vs. 70.9 days, p=0.001). Preoperative TA MMT was slightly higher in the R group, which improved to 4.4 at final follow-up compared with 1.3 in the U group (p=0.001). At final follow-up, the R group showed significantly better JOABPEQ walking ability and RMDQ scores. Minimal clinically important difference achievement rates were consistently higher in the R group, although most differences were not statistically significant. Conclusions: TA recovery in drop foot due to LDDs was associated with better walking ability and favorable PRO trends. Although statistical significance was limited, timely intervention and muscle recovery appear crucial for optimizing mid-term functional outcomes.