ABSTRACT

Detailed anatomical knowledge of the accessory tendons of the dorsal compartments of the wrist is crucial for understanding the effects of tendon injury due to external trauma or rupture. This study was performed to investigate the variations of the extensor compartments of the wrist and a relation between the thickness of extensor digiti minimi (EDM) and abductor pollicis longus (APL) tendons and accessory extensor digiti quinti proprius (EDQP) slip to the little finger.

Fourteen fixed wrists of adult cadavers were dissected. The tendon variations in the extensor compartments of the wrist and their abnormal insertion sites were recorded, and the number, length, width, and type of accessory tendons were also recorded.

A double tendon of the extensor digiti minimi was detected in one female cadaver out of the 14 fixed cadavers. Ulnar and radial tendons of the EDM were detected in the right wrist of one female cadaver. The radial tendon was accepted as an accessory EDQP but did not join the extensor digitorum (ED), and the ulnar tendon was normal. Four out of fourteen wrists (28.5%) had APL tendon variations. The lateral was accepted as the main APL and the medial as the accessory tendon. A thin accessory tendon was detected from the extensor carpi ulnaris (ECU) at the ulnar styloid process.

Tendon variations of the dorsal compartments of the wrist and the relationship between the ED slip and accessory tendons should be considered when planning surgical treatment. The presence of accessory tendons might assist in finding alternative tendon sources for tendon grafts.