Surgical Reconstruction of Metatarsal Type Preaxial Polydactyly Using an Amalgamating Osteotomy.

ABSTRACT

BACKGROUND: Polydactyly of the foot is a relatively common condition. Approximately 15% of cases are preaxial, with one third of these cases involving duplication of the metatarsal [metatarsal type preaxial polydactyly (MTPP)].Surgical reconstruction of polydactyly is indicated to improve shoe tolerance. Reconstruction of MTPP has traditionally involved resection of the hypoplastic lateral ray in addition to soft tissue reconstruction to correct hallux varus. Poor postoperative results have frequently been reported, primarily due to residual hallux varus. We present a novel surgical technique for the treatment of children with MTPP presenting with a cosmetic lateral hallux, involving an amalgamating osteotomy that permits retention of the stable medial metatarsotarsal joint while avoiding the complication of residual hallux varus. METHODS: This was a retrospective case series describing the surgical technique of an amalgamating osteotomy in the treatment of patients with MTPP and a cosmetic lateral hallux. The surgical technique involves corresponding metatarsal osteotomies of the medial and lateral halluces, with amalgamation of the metatarsals and ablation of the residual medial hallux, without the need for extensive soft tissue reconstruction. Clinical and radiologic outcomes were evaluated at a minimum of 2 years postoperatively in 2 patients who underwent this technique. RESULTS: Two children, 1 female and 1 male, underwent an amalgamating osteotomy at the age of 31 and 18 months, respectively. At latest follow-up, 7.3 and 2.8 years after osteotomy, respectively, both patients displayed an excellent functional result according to the Phelps and Grogan clinical outcome scale. Plain radiographs in both cases demonstrated a well-aligned first ray with no growth abnormality and no hallux varus. CONCLUSIONS: We have presented a novel surgical technique for the reconstruction of MTPP presenting with a cosmetic lateral hallux, involving an amalgamating osteotomy without extensive soft tissue reconstruction. This simple technique maintains the stable medial metatarsotarsal joint, permits ongoing longitudinal metatarsal growth, and avoids the complication of hallux varus. LEVEL OF EVIDENCE Level IV-case series.