Purpose: Leaving extensor pollicis longus (EPL) tendon out of the retinaculum in cases performed through a dorsal approach at the level of the extensor retinaculum after opening the 3rd extensor compartment reduces risk of adhesion and rupture. The aim of this study was to attempt to understand whether leaving EPL in the subcutaneous tissue that is released from the extensor compartment during surgery, without reconstructing the third extensor compartment, causes any change to extension strength and range of motion (ROM) of the interphalangeal (IP) and metacarpophalangeal (MCP) joints of the thumb.