[Flexor carpi radialis tendon rupture following percutaneous osteosynthesis of the scaphoid: a case report]

We present a rare complication of percutaneous osteosynthesis of a scaphoid fracture. A 19-year-old professional handballer presented with a fracture of the scaphoid classified B2 according to the Herbert classification: the fracture was fixed with a percutaneous screw. The fracture was united by six weeks despite resumption of training eight days postoperatively. Subsequently, the patient presented with pain over the flexor carpi radialis (FCR) tendon together with reduction of wrist flexion strength suggested an FCR tendonitis. A CT scan with injection eliminated the diagnosis of non-union and showed protrusion of the distal end of the screw. After the failure of conservative treatment (corticosteroid injection), removal of the screw and synovectomy of the FCR were scheduled. During the procedure, attrition of the FCR tendon with scar tissue and metal inclusions in its fibres were observed. A visual examination of the screw's distal end showed a distortion of its hexagonal outline due to hammering, leading to metal projection likely to have caused the FCR tendon's attrition. We recommend the systematic burying of these canulated screws as well as changing any screw damaged during its insertion.