Advances in small arthroscopy have enabled a minimally invasive surgery for thumb carpometacarpal joints. However, surgery is often difficult using standard CM-radial (CM-R) and CM-ulnar portals (CM-U). Here, we describe the clinical applications and complications associated with using thenar portal (TP) and standard portals.

Arthroscopic surgeries of thumb carpometacarpal joint were performed in twenty-one patients including fifteen patients with osteoarthritis and six Bennett's fracture-dislocations. Complications and the frequency of use associated with each portal were evaluated.

Complications associated with the CM-R portal comprised paresthesia due to damage of the radial nerve branches in two patients. No nerves were damaged but the operation scar became tender at the TP in three patients. The CM-R was used at a lower frequency when the TP was utilized.

The clinical use of TP may decrease the risk of radial sensory nerve damage through decreasing frequency of use of the CM-R that is located near the nerve.

IV.