Cadaveric modeling of the pronator teres rerouting tendon transfer.

The purpose of this study is to report the biomechanics of the supination effect of the pronator teres rerouting procedure and to determine the optimum insertion point for the transfer using a cadaveric model. Pronator teres rerouting procedures were performed on 5 fresh-frozen above-elbow cadaver specimens mounted in a forearm rotation mounting frame. The pronator teres was detached from its native insertion and tested at 6 insertions on the radius. The amount of rotation of the forearm was measured after loading of the pronator teres muscle for each insertion site. The experiments were repeated by placing the pronator teres 1 cm proximal to the 6 experimental insertion sites for a total testing of 12 insertions. The results of this study show that placement of the pronator teres through the interosseous membrane, around the radius, with reinsertion onto the volar surface produced the greatest amount of forearm supination. Rerouting of the pronator teres tendon produces supination through a windlass effect when the tendon is rerouted through an interosseous window and reinserted onto its original insertion or onto the volar surface of the radius. Placement of the insertion 1 cm proximal on the radius did not affect the amount of forearm supination compared with 6 original insertion sites.