Dynamic plantar pressure distribution, strength capacity and postural control after Lisfranc fracture-dislocation

Substantial progress has been made in the operative treatment of Lisfranc fractures, however, the prognosis remains poor. We hypothesized that Lisfranc injuries change the postural control and muscle strength of the lower limb. Both are suggested to correlate with the clinical outcome and quality of life. 17 consecutive patients suffering from a Lisfranc fracture dislocation were registered, underwent open reduction and internal fixation and were followed-up for 50.5±25.7months (Mean±SDM). Biomechanical analysis of muscle strength capacities, postural control and plantar pressure distribution was assessed >6 month postoperatively. Results were correlated to clinical outcome (AOFAS, FFI, Pain, SF-36). The isokinetic assessment revealed a significant reduction in plantar flexor and dorsal extensor peak torque of the injured limb compared to the uninjured limb. The dorsal extensor peak torque thereby correlated well with clinical outcome. Altered postural control was evident by a significant reduction in unilateral stance time, from which we calculated a strong correlation between stance time and the isokinetic strength measurement. Plantar pressure measurements revealed a significant reduction in peak pressure under the midfoot and of Force-Time Integral beneath the second metatarsal. Sufficient rehabilitation is crucial to the clinical outcome following anatomical open reduction of Lisfranc fracture-dislocation. The present study supports a rehabilitation approach focussing on restoring proprioception and calf muscular strength including isometric exercises of the dorsal extensors.