Arthrodesis of the first tarsometatarsal joint for correction of the advanced splayfoot accompanied by a hallux valgus.

OBJECTIVE: Arthrodesis of the first tarsometatarsal joint for the treatment of a painful splayfoot with the aim to restore a normal weight bearing on the first ray. Correction of hallux valgus deformity.

INDICATIONS: Advanced splayfoot deformity with a first intermetatarsal angle > 18 degrees. Hypermobility of the first tarsometatarsal joint with reduced weight bearing on the first ray and development of a transfer metatarsalgia. Painful, primary or secondary osteoarthritis of the first tarsometatarsal joint. Recurrence of splayfoot deformity after previous attempt at surgical correction. Elevation of the first ray such as after developmental clubfoot. Metatarsus primus varus deformity accompanied by hallux valgus in the presence of a hypermobile flatfoot.

CONTRAINDICATIONS: Minimal or moderate splayfoot deformity with a first intermetatarsal angle < 17 degrees and a clinically stable first tarsometatarsal joint. Untreated hindfoot deformities such as flatfoot combined with heel valgus. Inability to use walking aids for postoperative partial weight bearing. Insufficient circulation of forefoot.

SURGICAL TECHNIQUE: Dorsomedial incision overlying the first tarsometatarsal joint. Splitting of the extensor aponeurosis medial to the tendon of the extensor hallucis longus. Subperiosteal exposure of the first tarsometatarsal joint. Opening of the joint. Judicious removal of articular cartilage and resection of a laterally based bony wedge from the medial cuneiform for correction of the increased first intermetatarsal angle. Manual correction of the splayfoot with concomitant plantar displacement of the base of the first metatarsal. Selection of properly fitting fixed-angle plate and internal fixation. Soft-tissue correction at the first metatarsophalangeal joint or metatarsal neck osteotomy to realign the articular surface of the first metatarsal head.

RESULTS: Clinical and radiologic results based on 56 patients (64 feet) followed up for an average of 8.2 months.

COMPLICATIONS: one reflex sympathetic dystrophy, four nonunions of the first tarsometatarsal joint (6.2%). Radiologic evidence of consolidation at a mean of 9 weeks. Improvement of the first intermetatarsal angle from 20.4 degrees to 11.2 degrees. Pressure measurement showed a significantly improved load-carrying capacity of the first ray. The score of the American Orthopaedic Foot and Ankle Society improved significantly (p < 0.01) from 51 to 92 points.