Accessory head of flexor pollicis longus muscle and its clinical significance

Flexor pollicis longus muscle may have accessory slips which arise from coronoid process of ulna or medial epicondyle of humerus; known as accessory head of flexor pollicis longus or Gantzer’s muscle. It runs downwards and obliquely to join the tendon of flexor pollicis longus. It may compress median, ulnar and anterior interosseous nerves and produce many neurological conditions. Aim of this study was to note incidence and morphology of accessory head of flexor pollicis longus. We used 57 adult Indian cadavers (52 males and 5 females) and each forearm was dissected carefully to see the existence of accessory heads of the flexor pollicis longus and its morphology, its relations with nearby structures. Weobserved it in 76.31 % specimens. It was present bilaterally in 53.84% male cadavers. We noted that, the median nerve ran over the accessory head of flexor pollicis longus while the anterior interosseous nerve ran posteriorly. Compression of these nerves from this muscle could occur and give rise to anterior interosseous syndrome. Therefore, the precise knowledge about this muscle should be kept in mind by clinician and surgeons.