The assessment of adolescent hallux valgus before and after first metatarsal osteotomy--clinical and walkway studies.

A comprehensive method of evaluating the feet of patients with adolescent hallux valgus both before and after surgical correction is described. Serial clinical, photographic and radiological studies were made and a dynamic assessment of gait was carried out using a load-sensitive walkway. Observations were made on 36 feet in which hallux valgus was treated by a modification of the Wilson oblique metatarsal osteotomy, with removal of a wedge of bone and screw fixation. In the first six months after operation, there was a lateral shift of the weight-bearing pattern in the forefoot and less weight was taken on the toes, but there was a tendency to return to the pre-operative distribution of weight during the next four years. Persistence of the lateral shift of weight-bearing appeared to result from elevation of the first metatarsal head secondary to shortening of the first metatarsal during the osteotomy. This can be avoided by deliberate depression of the first metatarsal head at the time of operation and fixation of the fragments in the required position with a screw.