Surgical Management of Pediatric Muller-Weiss Disease.

INTRODUCTION: Muller-Weiss disease (MWD) involves the idiopathic collapse and fragmentation of the navicular bone. Patients present with pain and deformity. Pediatric cases are rare, and it is distinct from Kohler disease. Surgical management can include internal fixation of the navicular, calcaneal lengthening osteotomy, and arthrodesis. CLINICAL PRESENTATION: A healthy 10-year-old boy with a family history of MWD presented with midfoot pain and toe walking. He had hindfoot equinization, pes planus deformity, and forefoot abduction. Imaging revealed a comma-shaped navicular with lateral collapse and fragmentation. He had a short lateral calcaneal column relative to the talus. Following unsuccessful nonsurgical management, he underwent internal fixation of the navicular, calcaneal lengthening osteotomy, and sliding tendoachilles lengthening. Following recovery, he was pain-free with radiographic union of the navicular fragment. DISCUSSION: We propose he developed MWD through mechanical compression of the lateral navicular, resulting from a short lateral calcaneal column relative to the talus. Our poor understanding of MWD creates challenges in its diagnosis and management. Although rare in children, it is not exclusively a disease of adulthood. Early recognition may allow correction of underlying deformity to prevent progressive fragmentation and degenerative deformity.