Anatomical And Clinical Studies For Deep Branch Of Ulnar Nerve Entrapment Syndrome At The Arch Of Adductor Muscle Of Thumb

Objective : to investigate the anatomical factors and treatmentmethods of compression syndrome of deep branch of ulnar nerve at thearch of adductor muscle of thumb.Methods : Deep branch of ulnar nerve at the origin of adductor muscleof thumb in 20 adult cadaveric hand were observed. 5 cases of ulnarnerve entrapment syndrome at the arch of adductor muscle of thumb wereretrospectively analyzed.Results : At the origin of adductor muscle of thumb, the deep branchof ulnar nerve was covered by 3 types of anatomical structures: â‘ Membranous Type(12 cases, 60.0%, Type I);â‘¡Ligamentous Type(6 cases,30.0%, Type II);â‘¢Tendinous Type(2 cases, 10.0%, Type III). For 5patients, there existed Type III tendinous arch in 4 cases, and TypeII ligamentous arch in 1 case with a thecal cyst.Conclusion : Arch at the origin of adductor muscle of thumb is animportant factor for the ulnar nerve compression syndrome. Incisionof the fibrous arch at the base of the third metacapel could treatthe sydrome.