Distal Nerve Transfers for Foot Drop: A Systematic Review and Meta-Analysis.

BACKGROUND

Foot drop from peroneal nerve palsy causes steppage gait and functional disability. Tendon transfer is reliable but sacrifices native biomechanics. Distal nerve transfer (DNT) reinnervates dorsiflexors, potentially restoring more physiologic function. This study aimed to systematically review and meta-analyze the clinical outcomes of DNT for foot drop and to identify key prognostic and technical factors that inform contemporary reconstructive decision-making.

METHODS

Following PRISMA, we searched MEDLINE, EMBASE, and Cochrane (through September 2025) for clinical studies of DNT to the deep peroneal nerve (DPN) or its branches. Primary outcome was the proportion achieving Medical Research Council (MRC) grade ≥ 3 dorsiflexion; secondary outcome was MRC ≥ 4. Pooled proportions were estimated with random-effects meta-analyses using binomial generalized linear mixed models, reporting 95% confidence intervals, heterogeneity (I2), and 95% prediction intervals; sensitivity and small-study analyses are detailed in the Supplement.

RESULTS

Ten studies (nine clinical, one cadaveric; n = 120) met inclusion. Across k = 7 clinical series (N = 101) with extractable data, pooled MRC ≥ 3 was 0.57 (95% CI 0.41-0.72, I2 = 59.6%, τ2 = 0.032, 95% PI 0.29-0.83). Excluding the iatrogenic series yielded 0.50 (95% CI 0.35-0.66; I2 = 42.1%). For MRC ≥ 4 across k = 5 series (N = 42), the pooled estimate was 0.33 (95% CI 0.12-0.58; I2 = 67.9%, τ2 = 0.041, 95% PI 0.08-0.73). AFO independence paralleled strength recovery. Donor morbidity was low.

CONCLUSIONS

DNT restores antigravity dorsiflexion in approximately half of appropriately selected patients, with one-third reaching near-normal strength. Early surgery (≤ 12 months) and viable anterior compartments optimize outcomes. Tendon transfer remains a reliable fallback and can be combined with DNT in complex cases.