Extensor carpi radialis longus avulsion: Presentation, treatment rationale and outcome of an unusual fracture

Abstract

Avulsion fracture of the base of the second metacarpal is a rare injury due to the stability of the carpometacarpal joints. There are few documented cases in the literature of extensor carpi radialis longus (ECRL) avulsion. The ECRL avulses from the base of the second metacarpal usually as a result of forced wrist hyperflexion and can be exacerbated with the hand in ulnar deviation. This is often as a result of a fall and the patient usually presents with pain in the region of, and dorsal to, the anatomical snuffbox. The base of the second metacarpal articulates with the base of the third metacarpal, capitate, trapezium and trapezoid. The ECRL has its origin on the lower third of the lateral epicondyle and the supracondylar ridge of the humerus and inserts distally into the base of the second metacarpal. The actions of ECRL are wrist radial deviation and wrist extension, the ECRL imparting a greater moment for radial deviation than the extensor carpi radialis brevis, while the opposite relationship is found for wrist extension. This paper presents the case of a patient with this injury, the diagnostic images, subsequent surgical and therapy management and final outcome.