Supernumerary extensor pollicis longus tendon masking an extensor pollicis longus rupture following non-surgical treatment of a distal radius fracture

Abstract

Extensor pollicis longus tendon pathology is a recognised complication following non-surgical treatment of non-displaced distal radius fractures. Tendon entrapment typically presents with pain, but preservation of thumb retropulsion during complete rupture results in loss of active thumb retropulsion and tenodesis effect. We present the case of a 52-year-old woman who developed extensor pollicis longus tendon entrapment with full active thumb extension following a non-displaced distal radius fracture. During her elective third dorsal compartment release, the extensor pollicis longus tendon was found to be completely ruptured and a rare supernumerary extensor pollicis longus tendon was found emerging from the fourth dorsal compartment. Gentle traction of this tendon resulted in thumb interphalangeal joint extension and simultaneous index finger metacarpophalangeal joint extension. An extensor indicis proprius to extensor pollicis longus tendon transfer was performed. At her final 6-month follow-up, she had painless full active thumb motion comparable to her contralateral side.

Accessory Extensor Pollicis Longus Spanning the Fourth Dorsal Compartment of the Wrist: A Case Report

“…For instance, in a report describing a full EPL tendon rupture following a distal radius fracture, the patient could extend their distal thumb phalanx, albeit to a lesser extent, due to the accessory EPL tendon [ 7 ]. Another advantage would be to use this accessory tendon as a graft in light of a tendon rupture repair.…”

Accessory Extensor Pollicis Longus Tendon Classification Modification

“…There have been case reports of accessory tendons to the thumb and index finger identified during cadaveric dissection and during emergency and elective surgery. 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 A cadaveric study of 95 dissections reported the observed incidence of duplicate EPL tendons to be 32.6% and the observed incidence of accessory tendons to the index finger to be much rarer at 3.2%. 13 The deviation in tendon morphology of the thumb and index finger has been reported as either connections between the EIP and EPL tendons, doubling of the individual tendons, doubling of the muscle belly or abnormal origin or insertion.…”