Published online Jul 18, 2016. doi: 10.5312/wjo.v7.i7.448
Peer-review started: February 1, 2016
First decision: April 15, 2016
Revised: April 17, 2016
Accepted: May 7, 2016
Article in press: May 9, 2016
Published online: July 18, 2016
We are reporting a case of extensor pollicis longus tendon rupture which did not require tendon transfer owing to the ability of the intact extensor pollicis brevis (EPB) to fully hyperextend the thumb interphalangeal joint. The thumb metacarpophalangeal joint was also able to be fully actively extended by the EPB. Previous anatomical studies have demonstrated that the insertional anatomy of the EPB tendon is highly variable and sometimes inserts onto the extensor hood and distal phalanx, which is likely the mechanism by which our patient was able to fully extend the thumb interphalangeal joint. Despite the potential for the EPB to extend the IP joint of the thumb, virtually all previously reported cases of extensor pollicis longus (EPL) tendon rupture had deficits of thumb IP extension requiring tendon transfer. This case highlights the potential ability of the EPB tendon to completely substitute for the function of the EPL tendon in providing thumb IP joint extension.
Core tip: The extensor pollicis brevis may be able to substitute for extensor pollicis longus (EPL) function in some patients when EPL has ruptured.