In vivo determination of available brachioradialis excursion during tetraplegia reconstruction

The brachioradialis muscle is a common donor in tetraplegia reconstruction. The purpose of this study was to determine the available excursion of the brachioradialis during graduated release of its insertion sites. Fourteen extremities in 10 patients with cervical spine injuries underwent surgical reconstruction for restoration of hand function using the brachioradialis as a donor for one of the restored movements. At the time of surgery the brachioradialis was exposed along the forearm and a wire was inserted into the muscle followed by excitation with a biphasic, asymmetrical, charge-balanced waveform. A 12-Hz frequency and 20-mA current were used to stimulate the muscle while the pulse duration was varied between 0 and 200 milliseconds to achieve maximum contraction. Average brachioradialis excursion after incision of the radial styloid insertion site was 8 mm and 14 mm after mobilization to the musculotendinous junction. Further release of the fascial connections and mobilization of the muscle belly increased the excursion to an average of 61 mm. The increase in excursion after fascial release and muscle mobilization was significant and should be performed to obtain maximum available excursion.