Management of Lower Extremity Deformity in Children with Hereditary Multiple Exostoses.

Hereditary multiple exostoses (HME) is a rare genetic disorder characterized by multiple benign, cartilage-capped bony tumors, most often found at the juxta-epiphyseal regions of long bones. Patients with HME often present with lower limb deformities, including coxa valga, genu valga or vara, and ankle valgus. This review aims to thoroughly examine the existing literature on surgical options for addressing angular deformities of the hip, knee, and ankle associated with HME in children and to recommend the most effective surgical management. It does not cover the simple removal of exostoses or isolated treatment for limb-length discrepancy. Key Concepts: (1)The most common lower extremity malalignment deformities secondary to hereditary multiple exostoses (HME) are coxa valga of the hips, genu valgum or varum of the knees, and ankle valgus.(2)Temporary hemiepiphysiodesis (growth guidance) using transphyseal screws, staples, and tension band plates has become a mainstay for treating deformity in children with HME, but there is still much unknown.(3)Tibial deformities are largely proximal and/or distal valgus angulations, which are associated with short fibulas.(4)Ankle valgus should be addressed to prevent late ankle pain and degeneration.