First Metatarsal Lengthening

Abstract

ABSTRACT Shortening of the first metatarsal is known to occur during hallux valgus surgeries. If the shortened first ray disrupts the normal weight transfer, then transfer metatarsalgia may result. After failed conservative treatment, a common operative option is osteotomy of the lesser metatarsals. However, osteotomies of normal metatarsals further alter the normal anatomy and can significantly shorten the forefoot. Restoration of the first metatarsal length using distraction osteogenesis may more closely restore normal foot anatomy and biomechanics and subsequently treat transfer metatarsalgia. This article describes the operative technique and results from distraction osteogenesis using a 4-pin single mini-external fixator. Lengthening is complete once the affected first metatarsal is equal in length to the adjacent second metatarsal. In the authors' series of 5 patients, the mean consolidation period was 15.8 weeks. Preoperative and postoperative length of the first metatarsal was expressed as a percentage of the length of the ipsilateral second metatarsal. The preoperative mean was 77.1%, and the postoperative mean was 93.8%. There were no nonunions or malunions, and no secondary procedures such as bone grafting were required. There were no infections, malrotation, or malalignment. All patients reported reduction in their forefoot pain and returned to a nonantalgic full weight-bearing gait.