FA1: THE RESULTS OF OPENING WEDGE OSTEOTOMY OF THE MEDIAL CUNEIFORM. A RADIOGRAPHIC ANALYSIS

Abstract

We analyzed the radiographic results of patients treated surgically for flatfoot deformity and who underwent medial cuneiform opening wedge osteotomy as part of the operative procedure. The aim of this study was to confirm the utility of the cuneiform osteotomy as part of the correction of hindfoot and ankle deformity. All patients requiring operative management of flatfoot deformity between January 2002 and December 2007 were prospectively entered in a database. We selected all patients who underwent medial cuneiform opening wedge osteotomy. We measured standardized and validated radiographic parameters on pre and post-operative weight bearing radiographs of the foot. All radiographs were assessed using the digital imaging software package (Siemens). The following measurements were used: lateral talus-1st metatarsal angle; medial cuneiform to floor distance (mm), talar declination angle, calcaneal-talar angle, calcaneal pitch angle, 1st metatarsal declination angle, talonavicular coverage angle, and anteroposterior talus-1st metatarsal angle. Other variables including concomitant surgical procedures, healing of the osteotomy, malunion, and adjacent joint arthritis were also noted. There were 86 patients with a mean age of 36 years (range 9–80). 15 patients had bilateral surgery. The aetiology of the deformity was flexible flat-foot in 48, rupture of the posterior tibial tendon in 41, rigid flatfoot deformity with a fixed forefoot supination deformity in 7, and fixed forefoot varus with metatarsus elevatus in 5. In addition to an opening wedge medial cuneiform osteotomy, a lateral column lengthening calcaneus osteotomy was performed in 80, a gastrocnemius recession in 76, a supramalleolar osteotomy in 2, a triple arthrodesis in 4, a subtalar arthroerisis in 13, excision of an accessory navicular in 6, a tendon transfer in 15 and medial-slide calcaneal osteotomy in 8 patients. The mean lateral talus-1st metatarsal angle improved from 23° to 1°; the mean medial cuneiform to floor distance improved from 20mm to 34mm; the mean talar declination angle improved from 39° to 27°; the mean calcaneal-talar angle improved from 64° to 55°; the calcaneal pitch angle improved from 14° to 23°; the mean 1st metatarsal declination angle improved from 17° to 26°; the mean talonavicular coverage angle improved from 45° to 18°; and the mean anteroposterior talus-1st metatarsal angle improved from 19° to 0° Radiographical analysis confirms that the medial cuneiform opening wedge osteotomy is a reliable and valuable surgical tool in the correction of the forefoot which is associated with flatfoot deformity and that arthrodesis of the 1st metatarsocuneiform joint may not be required to obtain correction of the elevated 1st metatarsal.