Anatomic study of the abductor pollicis longus: a source for grafting material of the hand.

Interposition grafting material is used frequently to treat osteoarthritis of the base of the thumb or tendinous and ligamentous injuries of the hand. The observation of duplicated tendons in the first dorsal compartment of the hand prompted us to explore the possibility of using the accessory abductor pollicis longus (AAPL) tendon as grafting material. Based on dissections of 78 cadaveric upper limbs, we describe the number of tendons in the first dorsal compartment of the hand, the number of muscle bellies, their innervation, their insertion site, and the tendon dimensions to determine whether the AAPL can be considered a true tendon. The AAPL was present in 85% of the hands. Average length, width, and thickness (in millimeters) of the APL were of 69.3, 5.2, and 2.1, respectively. Average length, width, and thickness (in millimeters) of the AAPL were of 69.2, 3.3, and 1.6, respectively. No differences in dimension of the tendons were found between the APL and the AAPL. The dimensions of the tendinous portion of the AAPL are similar to those of the APL and can be considered a true tendon. When present, the AAPL is a suitable source of local grafting material.