Walking and Running Plantar Pressure Analysis before and after Resection of Tarsal Coalition

Abstract

Conservative treatment failure in symptomatic tarsal coalition usually mandates bar resection as a preferred operative alternative. The outcome of this procedure generally has been assessed by clinical measures. The purpose of our study was to evaluate whether plantar pressure distribution is normalized after bar resection. This study compared three groups: nine candidates for resection of tarsal coalition, nine patients between 2 and 4 years after bar resection (not the same patients who were candidates for resection), and nine control subjects. The ankle and hindfoot were evaluated according to the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale. Mean plantar pressure and mean normalized impulses were calculated during walking and running. Significantly higher AOFAS scores were demonstrated in the postoperative group compared with the preoperative group (p<0.01). Medial midfoot pressures demonstrated the most consistent differences between groups. Preoperative feet had significantly higher medial midfoot pressures compared with the control group both during walking and running. Feet that had resection did not demonstrate significantly higher medial midfoot pressures during walking compared with the control group. However, during running, this segment's pressures were significantly higher both in preoperative (p=0.000) and in postoperative (p=0.023) feet compared with the control group. Heel segments revealed decreased pressures laterally both in preoperative feet and in postoperative feet compared with the control group. Running demonstrates that normal plantar pressures are not recreated after resection of tarsal coalition. However, close to normal walking pressure distribution is consistent with the favorable clinical outcome observed in most patients after bar resection. Regaining full recreational activity after resection of a tarsal coalition, i.e. running, may have implications on abnormal foot loading and torque, thus promoting degenerative changes in the subtalar and adjacent joints.