Chapter 9 - Bobby Marcelo: A 48-Year-Old Male With a Painful Bump on the Back of His Wrist

Abstract

Carpal boss syndrome, or os styloideum, is characterized by localized tenderness and sharp pain over the junction of the second and third carpometacarpal joints. The pain of carpal boss syndrome results from exostosis of the second and third carpometacarpal joints or, more uncommonly, a loose body involving the intraarticular space. Patients often report that the pain is worse after rigorous physical activity involving the hand rather than during the activity itself. The pain of carpal boss syndrome may also radiate locally, thus confusing the clinical presentation. The disease typically affects the dominant hand, although carpal bossing is present approximately 15% of the time in patients suffering from carpal boss syndrome. Carpal boss syndrome has a slight male predominance and a peak incidence in the middle of the third decade of life. Trauma is often the common denominator in the development of carpal boss syndrome.