Longitudinal Epiphyseal Bracket of the First Metatarsal: A Case Series on Treatment of Deformities Associated.

Abstract

Longitudinal epiphyseal bracket of the first metatarsal, also known as first enclosed metatarsal, is a rare congenital disorder characterized by an abnormal development in the length of the first metatarsal ray because of the asymmetric presence of a longitudinal epiphyseal bracket. This causes interruption in the lengthways development of the affected bone, which becomes squat and short, with a trapezoidal or triangular shape, leading to a hallux varus deformity. First enclosed metatarsal occurs in 2% to 14% of all congenital defects in the hands and feet; with bilateralism in 75% of cases and a greater incidence in male patients. The deformity is classified as a differentiation defect; it is frequently associated with abnormalities such as syndactyly or polydactyly. There are different surgical treatments reported in the literature. Most of them are aimed at the excision of the epiphyseal bracket before complete skeletal maturity and frequently in the first year of life to promote a normal lengthways growth of the bone. In this study, the authors present three cases of bilateral first enclosed metatarsal in which the surgical treatment, aimed at lengthening the first metatarsal ray by using the Penning Minifixator, was instead carried out at the end of growth. This different surgical approach allowed the planning of a surgical operation involving both the skeletal structures and the surrounding soft tissue.