Free Tissue Transfer versus Native Plantar Flap Reconstruction After Transmetatarsal Amputation: A Proof-of-Concept...

Free tissue transfer (FTT) can be used to achieve functional limb salvage in patients undergoing transmetatarsal amputation (TMA). However, the added bulk of the FTT can limit footwear options and hinder ambulation. Dysfunctional gait mechanics may lead to uneven pressure distribution and an increased risk of ulceration. In this proof-of-concept study, wearable sensor data were utilized to compare gait patterns between TMA patients closed with free tissue transfer (FTT) versus those closed with native plantar flaps to assess the biomechanical impact of FTT closure in patients undergoing TMA.

Nineteen patients who underwent TMA (n = 14 [73.7% with native plantar flap] and n = 5 [26.3% with FTT]) completed a 120-second gait test with wearable sensors. Gait parameters included cadence (steps per minute), speed (meters per second), stride length (meters), stride duration (seconds), single- and double-limb support (%), elevation at midswing (centimeters), and root mean square (RMS) sway (centimeters), a marker of postural instability. Demographics, comorbidities, and operative details were collected. Groups were compared using univariate and multivariate analyses.

There were no significant differences observed between cohorts with respect to gait speed (0.85 vs 0.85 m/s, P = 0.997), cadence (97.8 vs 98.5 steps/min, P = 0.883), stride duration ( P = 0.797), or elevation at midswing (1.64 vs 2.73 cm, P = 0.131). RMS sway was statistically significantly higher in the FTT group (0.35 vs 0.20 cm, P = 0.041), suggesting greater postural instability. On multivariate analysis, flap type was not independently associated with RMS sway ( P = 0.839), although higher BMI trended toward significance ( P = 0.116). The FTT group had significantly higher BMI (35.5 vs 28.1 kg/m 2 , P = 0.018) and greater prevalence of peripheral vascular disease (PVD) (80.0% vs 21.4%, P = 0.038).

Most spatiotemporal gait parameters were similar between TMA patients reconstructed with FTT and those with a native plantar flap. Although FTT patients had significantly higher RMS sway on univariate analysis, this was not independently associated with flap type after adjusting for confounders. This proof-of-concept analysis suggests that FTT, despite its bulk, may not significantly impair postamputation ambulation and remains a valuable limb salvage option when native plantar flap coverage may not be feasible.