The function and the strength of the thumb is not affected when the extensor pollicis longus tendon is left out of the extensor retinaculum

ABSTRACT
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.
Patients and methods: 20 patients operated on between 1995 and 2013 were evaluated retrospectively. The EPL tendons
of all patients were left out of the extensor retinaculum after opening the 3rd extensor compartment through a dorsal
approach to wrist. The following surgeries were performed: wrist arthrodesis in four patients, vascularized bone flaps
from the 4th ECA (extensor compartmental artery) for Kienböck’s disease in two patients, open reduction after perilunate
fracture-dislocations in two patients, proximal row carpectomy after Kienböck’s disease in two patients, and distal radius
fracture surgery through a dorsal approach in six patients. Extension strength (in kg) and voluntary ROM (in degree) of
the MCP and IP joints of the thumb were measured. Opposite extremity values were assessed and compared statistically.
Results: No statistically significant reduction was determined in strength and ROM of IP and MCP joints of the thumb on
the operated side of patients whose EPLs were left out of the retinaculum compared with the non-operated side.
Conclusion: It was determined that leaving the EPL tendon out of the retinaculum in cases with increased risk of adhesions
and rupture did not cause marked muscle weakness or loss of range of movement.