Functional results after extensor indicis proprius to extensor pollicis longus tendon transfer for ruptures associated with distal radius fractures.

Rupture of the extensor pollicis longus (EPL) tendon is a recognised complication after distal radius fracture (DRF) that leads to loss of active thumb extension. Transfer of the extensor indicis proprius (EIP) tendon to the EPL is one of the most common reconstructive procedures, but prospective outcome data are limited. This study evaluated functional and patient-reported outcomes after EIP-to-EPL tendon transfer exclusively in patients with EPL rupture secondary to DRF. Thirty consecutive patients (26 women, 4 men; median age 65 years, range 17-80) underwent EIP-to-EPL tendon transfer between 2021 and 2025 for EPL rupture secondary to DRF. Thumb motion, grip and pinch strength and QuickDASH scores were recorded at 3 and 6 months postoperatively. All motion parameters improved between 3 and 6 months. At 6 months, lift-off height recovered to approximately two-thirds, total thumb flexion to > 80% and radial/palmar abduction to about 90% of the contralateral side. Grip and pinch strength reached 79-85% of the uninjured hand. Mean QuickDASH score improved from 29 to 21 points (p = 0.015). In conclusion, EIP-to-EPL tendon transfer restores satisfactory thumb motion, strength and patient-rated function following EPL rupture associated with DRF. Functional recovery at 6 months is comparable to that of patients with uncomplicated DRFs. Clinical Trials registry no. NCT05264675.