Thenar muscle anatomic variation in carpal tunnel syndrome

Backgraound: Carpal tunnel syndrome (CTS) is the most common nerve compression neuropathy. It is a multifactorial syndrome and several systemic and local factors such as carpal tunnel anatomy and its variation change the size, shape and volume of this tunnel. In this study, we seek to explain the relation between anatomic variation of thenar muscle and CTS. This descriptive study was conducted on 155 patients with CTS undergoing operation. Care was taken to exclude patients with Rhumatoid Artritis, Hyperthyroidisem, Hypothyroidisom, Diabetic Melitus, acromegaly and previous fracture of distal wrist. During surgery thenar muscle anatomic variations of carpal tunnel have been observed. Of 155 patients, 140 were female (90.3%), and 15 male (9.7%) patients with the mean age of 57.9 years. The anatomic variations have been observed in 35(22.5%) patients. Thenar muscle anatomic variation in CTS is prevalent but further evidence is required.