Single Versus Double Tendon Transfer to Improve Shoulder External Rotation During the Treatment of Brachial Plexus Birth Palsy.

Abstract

<b>Background:</b> Tendon transfers are commonly performed in patients with brachial plexus birth palsy (BPBP) to improve function. Transferring 2 tendons in patients with C5-7 injury has the potential complication of loss of midline function. The purpose of this study was to investigate whether a single tendon transfer (1TT) as opposed to the traditional double tendon transfer (2TT) resulted in any differences in functional outcomes in patients with C5-7 BPBP. <b>Methods:</b> A retrospective review of all patients with C5-7 BPBP who underwent tendon transfers to improve shoulder external rotation over a 5-year period was performed at 2 institutions. Outcomes were assessed using the modified Mallet (MM) classification scores. <b>Results:</b> Twenty-two C5-7 patients had complete records of preoperative and postoperative MM scores, including 11 sex-matched patients in both the 1TT and 2TT groups. When comparing preoperative and postoperative MM categories, there were significant improvements in both the 1TT and 2TT groups for global abduction (<i>P</i> < .05 and <i>P</i> < .01, respectively) and external rotation (<i>P</i> < .00001 for both). Modified Mallet (MM) hand to neck scores were significantly improved in the 2TT group (<i>P</i> < .05) but not in the 1TT group (<i>P</i> = .053). Internal rotation scores significantly decreased in both groups (<i>P</i> < .001). Both groups demonstrated significant increases in total scores from the preoperative MM scores (<i>P</i> < .01). <b>Conclusion</b>: The 1TT and 2TT procedures result in substantial gains in upper extremity functions for patients with C5-7 BPBP as measured by the MM score, specifically within the global abduction and external rotation subcategories. However, a significant loss occurs in internal rotation for both groups.