[Rupture of the tendon of the m. flexor pollicis longus--a rare complication after surgery on the scaphoid bone].

Tendon ruptures in the hand without previous direct trauma are rare. Two cases are reported on with attrition of the flexor pollicis longus tendon. The first tendon rupture was along a dislocated cortico-cancellous bone graft following a Matti-Russe procedure; the second was by attrition over the screw of an AO-plate following internal fixation in scaphoid nonunion. Immediate tendon repair by interposition of a short tendon graft or by transposition of the superficialis flexor tendon of the ring finger is the treatment of choice. Further tendon ruptures can arise if surgical intervention is delayed.