Title : Outcomes and prognostic factors of surgical decompression in neurological foot drop: A systematic review and meta-analysis.
Abstract:
Objective: To evaluate the outcomes of surgical decompression and determine the factors predicting post-operative motor recovery in patients with unilateral footdrop and to propose a critical time frame for operative management.
Design: Systematic review and meta-analysis (using individualised patient-data for ordered logistic regression)
Subjects: The Population, Intervention, Comparator and Outcome (PICO) framework was used to define the eligibility criteria for the study. Adult patients (≥18 years) presenting with unilateral foot drop managed with surgical decompression +/- neurological rehabilitation
Methods: The systematic review and meta-analysis were carried out in accordance with the guidelines of the PRISMA statement. The MRC Power scale for ankle dorsiflexion was used uniformly throughout the review. The clinical outcome was the stage of recovery of motor function at final follow-up. An improvement in this parameter to >3 was used as the definition of recovery from foot drop. Predictors of outcome (patient age, gender, pre-operative severity, symptom duration, and level of pathology) were tested for statistical significance at the alpha level 0.05 using a multi-variate cumulative odds statistical model.
Results: The search returned 1037 studies of which 66 extractable individual patient cases were eligible for inclusion. Statistical analysis showed that patients aged ≤ 47 (median age in our sample) [P=0.045], and symptom duration ≤6 [P=0.01] had favourable post-operative outcomes. When comparing patiences across pre-operative severity, patients with the highest severity of footdrop (MRC=0/5) were up to 23 times more likely to have poorer post-operative motor function as compared to patients with lower severity clinical foot drop (MRC 3/5) [P=0.001]. Gender and level of pathology were not statistically significant prognostic factors. A critical time frame of </=6 weeks from onset was isolated as the sweet spot for surgical decompression after which outcomes started to dramatically shift towards poorer motor recovery
Conclusion: This meta-analysis isolated three factors significantly influencing motor recovery: (1) ≤47 years age, (2) symptom duration ≤6 weeks, and (3) pre-operative foot drop severity. We recommend a critical time-frame of under 6 weeks for surgical intervention from onset for this population. Further prospective, multi-centred research is required to explore these factors further.
