Anatomical variations of the abductor pollicis longus muscle tendon-relation to de Quervain`s disease

Anatomical variations of the abductor pollicis longus muscle tendons are essential for successful treatment of de Quervain`s disease. Surgery includes tenosynovectomy and decompression of the first extensor compartment of the hand. Many patients have additional tendons, usually the abductor pollicis longus.Materials and Methods: A total of 30 formol-carbol fixed human upper extremities from the autopsy material available at the Department of Anatomy, Histology and Embryology at the Medical University of Sofia were precisely examined for the presence of accessory tendons of the abductor pollicis longus muscle.Results: In all of the examined upper extremities, accessory tendons of the abductor pollicis longus muscle were detected. Accessory tendons of this muscle were established in 26 hands (86.7%), 18 of which had one accessory tendon (69.2%), 6 hands had two accessory tendons (23.1%), and 2 hands had three accessory tendons (7.7%). Mean length, width, and thickness of the accessory tendons were 63.2 mm, 4.9 mm, 1.9 mm respectively. The presence of accessory tendons showed no side-to side differences.Conclusion: Due to the high incidence of accessory tendons of the abductor pollicis longus muscle, we consider that such variation requires to pay close attention and could lead to misinterpretations during surgery of de Quervain disease.