Effect of Tendon Transfers and Extra-Articular Soft-Tissue Balancing on Glenohumeral Development in Brachial Plexus Birth Palsy
Background: Persistent muscle imbalance and soft-tissue contractures can lead to progressive glenohumeral joint deformity in patients with brachial plexus birth palsy. The objective of this investigation was to determine the effects of correction of external rotation weakness and internal rotation contractures with tendon transfers and extra-articular soft-tissue releases on glenohumeral development in patients with brachial plexus birth palsy.
Methods: Twenty-five patients with brachial plexus birth palsy who underwent latissimus dorsi and teres major tendon transfers to the rotator cuff—with or without concomitant musculotendinous lengthenings—were evaluated clinically and radiographically before the operation and at a minimum of two years (average, forty-three months) postoperatively. Shoulder function was prospectively assessed with use of the modified Mallet classification system, in which aggregate shoulder function is assigned a score of 5 to 25 points. Glenoid version and humeral head subluxation were quantified with magnetic resonance imaging or computed tomography, and glenohumeral deformity was graded.
Results: Clinically, all patients demonstrated improved global shoulder function, with the mean aggregate Mallet score improving from 13 points preoperatively to 18 points postoperatively (p < 0.01). As seen radiographically, the mean glenoid retroversion improved from 22° preoperatively to 16.5° postoperatively (p = 0.012). The mean posterior humeral head subluxation improved from 30% to 37% (p = 0.03). No patient had progressive worsening of the glenohumeral deformity.
Conclusions: Latissimus dorsi and teres major tendon transfers to the rotator cuff, combined with appropriate extraarticular musculotendinous lengthenings, significantly improved global shoulder function but led to only modest improvements in glenoid retroversion and humeral head subluxation. No profound glenohumeral remodeling occurs after these extra-articular rebalancing procedures, even when they are performed in patients of a young age. While the long-term clinical and radiographically apparent effects at skeletal maturity are uncertain, soft-tissue rebalancing procedures alone were found to have halted the progression of, but not to have markedly decreased, glenohumeral dysplasia at the time of a two to five-year follow-up.
Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.