Rupture ferme des poulies du pouce pendant un accouchement. Résultat de la reconstruction de la poulie A1

Abstract

Closed rupture of thumb flexor tendon pulleys is rare. No standardized surgical management has yet been defined, in contrast to the situation when reconstruction of pulleys of the long fingers is required. We describe a case of rupture of the three pulleys of the thumb that probably occurred after violent thumb grasp during delivery in absence of any other trauma. We reconstructed only the A1 pulley using an extensor retinaculum graft in the absence of remnants of the native pulleys. An extensor retinaculum strip was harvested via a transverse incision on the dorsum of the wrist at the level of the fourth extensor compartment. The graft was inserted in the proximal third of the proximal phalanx and fixed with two anchors positioned at both edges. At one year postoperatively, the result was satisfactory: pain had disappeared, active and passive thumb motion was complete, grip strength on the operated from 15 kg preoperatively to 26 kg postoperatively and thumb mobility evaluated with Kapandji score improved from 8/10 to 10/10. Guidelines for conservative or surgical management of closed ruptures of long finger pulleys are available, but not for thumb pulleys. The anatomical and biomechanical studies on FPL function motivated us to reconstruct only the complex A1-Av pulley, but the exact location of the reconstructed pulley was not clear. The biomechanical work Meyer zu Reckendorf et al. and Roloff et al. have similar conclusions that the new pulley should be placed in front of the proximal third of the proximal phalanx. Guelmi et al. reconstructed an A1-oblique complex using a modified Lister technique. Lister described satisfactory reconstruction of the A2 and A4 long finger pulleys using free grafts of the extensor retinaculum. Moutet considered that use of a synovialized tissue such as the extensor retinaculum was better than that of a tissue without any synovial layer and Bouyer et al. reported a series of 38 rock climbers who underwent successful pulley reconstructions using the extensor retinaculum. Thus, we chose an extensor retinaculum graft and, as no remnant of the old pulleys remained, we fixed the graft using anchors; this is effectively the Lister approach. Surgery is essential when the goal is recovering thumb mobility and eliminating bowstringing. Reconstruction of a single A1-Av pulley is sufficient; remnants of the native pulleys do not seem to be necessary and the extensor retinaculum remains the graft of choice.