First Extensor Compartment Entrapment After Distal Radius Fracture: Case Report

We report a unique case of first extensor compartment tendon entrapment (abductor pollicis longus [APL] and extensor pollicis brevis [EPB]) after a volarly displaced Salter-Harris type II distal radius fracture in a 16-year-old male. After unsuccessful treatment with closed reduction and pinning, open reduction was performed, which revealed the entrapment of the APL and EPB tendons within the fracture, requiring surgical dis-impaction, freeing of tendons, and stabilization with volar locking plate fixation. Post-operatively, there was no loss of reduction and the patient demonstrated full, pain-free thumb range of motion at follow-up. Extensor tendon entrapment typically presents with loss of motion or unsuccessful closed reduction. The extensor pollicis longus (EPL) tendon was most commonly involved and there were no prior reports of APL or EPB entrapment. Our case highlights the importance of considering tendon entrapment after a volar-displaced distal radius fractures, particularly when closed reduction is unsuccessful and recommend prompt surgical exploration in this setting.