A case of anomalous flexor carpi radialis brevis muscle and its clinical significance

Trowbridge S, Vidakovic H, Ham

Abstract

Aim: To present an atypical case of flexor carpi radialis brevis (FCRB) and its impact on minimally invasive procedures to the volar distal radius. Methods: Minimally invasive volar plate fixation was performed on 16 standard embalmed cadaveric forearms in the University of Otago anatomy department. The forearms were then dissected to analyse the effect on the local anatomy and the position of the metalware. Results: One case of a FCRB was identified, with an atypical split tendon and insertion into the transverse carpal ligament and base of the index and middle metacarpal. The surgical procedure caused radial muscle fibre tearing of the FCRB. Conclusions: The FCRB is a rare anomalous muscle of the wrist. Its presence has a detrimental effect on minimally invasive procedures to the volar distal radius. Surgeons operating on the distal forearm should be aware of this anatomical variation to prevent inadvertent injury.