The extensor pollicis longus tendon changes direction approximately 90 degrees around Lister tubercle at the dorsal distal radius as it crosses from the dorsum of the forearm to the dorsum of the thumb. The EPL uses the tubercle as a pulley, and this zone of tendon angulation is prone to attritional wear from the hard bony edge, particularly when the groove between the EPL and Lister tubercle is narrowed by callus following distal radius fracture.
Spontaneous EPL rupture at the Lister zone is a recognised complication occurring 4-12 weeks after distal radius fractures, even undisplaced ones, due to ischaemia and mechanical attrition within the narrow groove as post-fracture oedema subsides. It presents as sudden loss of active thumb IP extension. Emergency MRI confirms the diagnosis. Reconstruction uses extensor indicis proprius tendon transfer through the EPL tunnel from the index finger to the thumb. EPL tenosynovitis at Lister tubercle from inflammatory arthritis or repetitive trauma causes dorsal wrist pain reproduced by thumb extension.
EPL tendon rupture at the Lister tubercle zone 4-12 weeks after distal radius fracture from ischaemia and attritional wear in the narrowed groove, producing sudden loss of thumb IP extension, reconstructed by extensor indicis proprius tendon transfer.
Inflammatory or attritional tenosynovitis of the EPL in its groove around Lister tubercle produces dorsal wrist pain with thumb extension, point tenderness at the tubercle, and crepitus on thumb movement, managed by corticosteroid injection into the third extensor compartment.
