[Dislocation of the extensor tendons of the hand at the metacarpo-phalangeal level (zone V of Verdan)].
Traumatic dislocation of the extensor tendon over the metacarpophalangeal (MCP) joint is a rare lesion that is caused by the dysfunction or rupture of the sagittal band, which is an important stabilizing structure of the extensor tendon. This mechanical alteration presents itself as instability that affects function and may cause pain or snapping during finger motion. The diagnosis is made when ulnar dislocation of the extensor tendon is observed over the MCP joint. Nonsurgical treatment is successful and should be attempted when injuries are diagnosed within the first three weeks. Several surgical repairs have been described. We searched medical databases (Ovid, Medline) for papers on extensor tendon dislocation. We also revised our own cases of this injury. Our search resulted in 10 articles and four books. We found 18 patients with 21 injuries, 10 men and eight women. The most frequently affected finger was the middle one (in thirteen cases), followed by the index (in five cases), the fourth finger (in two cases) and the third one (in one case). Eight of our patients were treated conservatively and thirteen required surgical treatment. The surgical procedures performed were Wheeldons in seven cases; primary repair of the sagittal band and Wheeldon in four cases; primary repair alone in one case; and Carrolls in one case. The follow-up was between one and 34 years (average: 17.5 years). Extensor tendon dislocation in zone V is rare. When the diagnosis is made after three weeks of the lesion, the surgical treatment is recommended.