[Surgical treatment of cavovarus foot deformity considering dynamic pedobarography]

The operative management of cavovarus foot deformity using soft tissue and bony procedures turns out to be difficult. The present study was undertaken to evaluate an individualised operative treatment and changes in pathologic peak pressure pattern.

38 patients (average age 29.6 years, follow-up 44.6 months) with 59 operated feet were examined pre- and postoperatively. The clinical assessment included a questionnaire, ankle ROM and evidence of callosities. Correction of the longitudinal arch was measured on lateral X-rays using Hibbs', calcaneal pitch and Meary's angles. Plantar peak pressures were analysed in 16 patients (21 feet) using dynamic pedobarography (EMED SF4 system).

A good subjective functional and cosmetic result were achieved in 74.6 % of the feet. Walking distance, shoe wear and ankle ROM were improved. The height of longitudinal arch and calcaneal dorsiflexion decreased significantly (p = 0.001). An elevated first ray (overcorrection) was noted in 49.1 % of the cases. Postoperative plantar callosities occurred essentially under the lateral border of the foot but were improved compared to the preoperative situation. Dynamic pedobarography showed a significant postoperative (p = 0.002) decrease of loading under the lateral border, but peak pressures remained relatively high in the midfoot area. An increase of peak pressure under the great toe showed a functional improvement at push off.

The individualised operative concept has proved to be successful and leads to satisfaction with early improvement of foot function and shoe wear. Nevertheless it is difficult to restore muscular balance and normal foot posture in progressive neuromuscular disorders. A more selective use of the Jones procedure, an additional peroneus longus to peroneus brevis tendon transfer and a dorsal wedge extension osteotomy should prevent overcorrection of the first ray. To avoid a relapsed hindfoot varus deformity, a stabilising triple arthrodesis including lateral wedge resection should be performed early in severe deformities.