Accessory bones of the foot: clinical significance

In an effort to improve orthopedic clinic utilization, we reviewed the incidence of normal radiographic variants in the foot referred from the emergency room or outpatient clinic. The study was undertaken because normal radiographic variants are often confused with fracture. A retrospective study of all foot radiographs referred to the foot clinic at Madigan Army Medical Center was carried out. Distribution of normal radiographic variants and their confusion with fracture were evaluated. Thirty-six percent of all foot radiographs had identifiable accessory bones. The most common accessory bones in descending order were: os peroneum, accessory navicular, and os trigonum. All of the accessory bones identified in our study were asymptomatic. A thorough knowledge of location of normal accessory bones is mandatory and localization of foot symptoms by history and physical examination are necessary to facilitate correct diagnosis and treatment and to avoid unnecessary referral of these patients.