Anatomy of the extensor mechanism of the thumb in relation to the clinical presentation of extensor pollicis longus rupture

ConclusionsA DEE is present in the thumb that structurally and functionally resembles that of the fingers. Traction on the EPL tendon produced a compound movement including IPJ and metacarpophalangeal joint extension and supination of the entire first ray around the carpometacarpal joint. This compound movement is, in effect, the antagonistic movement to thumb opposition. This explains the profound loss of function associated with EPL rupture and suggests a more accurate test for EPL function than simply assessing for active IPJ extension.Level of evidence: Level IV, diagnostic study.
Source: European Journal of Plastic Surgery - Category: Cosmetic Surgery Source Type: research