Arthrodesis of the first metatarsophalangeal joint (MTPJ) is the gold standard treatment of a wide range of pathologies involving the 1st MTPJ. Numerous methods of internal fixation and bone end preparation have been reported to perform this procedure, however there is no universal technique. Therefore in an effort to bring together the best features of the different surgical techniques, a low profile contoured titanium plate (Hallu-S plate), with a compression screw, with a ball and socket bone end preparation were designed. A prospective study was carried out to determine the efficacy of using the Hallu-S plate for 1st MTPJ arthrodesis.

1st MTPJ arthrodesis, using the Hallu-S plate, was carried out in 11 consecutive patients. The procedure was performed in isolation and with other forefoot procedures. Cast immobilization was not used in patients with an isolated 1st MTPJ arthrodesis and the patients were allowed to mobilize (heel walking – full weight bearing) between 2 and 6 weeks postoperatively. The changes in the level of pain and activities of daily living using the AOFAS Hallux score, pre-operatively and at the last assessment, and the time to bone union were assessed.

The mean follow-up time was 10 months (STD 6 months) and there was statistically significant increase in the AOFAS Hallux score. All radiographs at 6 weeks showed bone union and an appropriate degree of dorsiflexion in relation to 1st metatarsal (20–25). The combination of the Hallu-S plate and a ball and socket preparation has both operative and biomechanical advantages over previously described techniques. This combination ensures the biomechanics of the 1st ray are maintained and a better functional result is achieved.

Introduction

The aetiology of hallux valgus is almost certainly multifactoral. The biomechanics of the first ray is a common factor to most. There is very little literature examining the anatomy of the proximal metatarsal articular surface and its relationship to hallux valgus deformity.