Anatomic variation of the extensor tendons to the ring and little fingers: a cadaver dissection study.

We found an anatomic variation of the extensor digiti minimi (EDM) and extensor digitorum communis (EDC) in a cadaveric dissection. The EDM had three tendon slips; two slips to the little finger and one to the ring finger metacarpophalangeal (MP) joint. The ring finger slip inserted in the extensor hood with the EDC. The EDC had a separate tendon to the little finger extensor hood. The EDM had an additional pulley distal to the extensor retinaculum. The MP joints of the little and ring fingers extended simultaneously upon pulling the EDM or the EDC. The third slip of the EDM could provide an extra donor site and possibly poses a unique clinical presentation.