This study evaluated 25 patients with persistent shoulder dysfunction due to obstetrical brachial plexus palsy who underwent latissimus dorsi and teres major tendon transfer to the rotator cuff with or without concomitant musculotendinous lengthenings at a minimum of 2 years (average, 43 months). There were 14 male and 11 female patients with a mean age at the time of surgery of 42 months (range, 14 to 168 months). Only 3 patients were operated on before the age of 2 years, and 2 patients were older than 6 years at the time of surgery. Therefore, 19 of the 25 patients were between the ages of 2 and 6 years of age. Clinically, the mean aggregate Mallet score improved from 13 points preoperatively to 18 points postoperatively. Each element of the modified Mallet classification improved and no patient exhibited deterioration in shoulder function. Radiographically, prior to tendon transfer surgery, the mean glenoid retroversion of the affected shoulders was 22 degrees (range, -3 degrees to 45 degrees) and the mean humeral head subluxation was 30 % (range, 0% to 70%). At a mean of 49 months following the tendon transfers and soft tissue releases, the mean glenoid retroversion of the affected shoulder was 16.5 degrees (range, -8 degrees to 40 degrees) and the mean humeral head subluxation of the affected shoulder was 37 % (range, 7 % to 66 %). The mean improvement in glenoid version was –5.4 degrees and the mean improvement in humeral head subluxation was 7 %. Overall, the glenohumeral joint morphology of the affected shoulder improved in 10 (40%) of the 25 patients but remained static in 15 (60%).
This is the first report on the affect of rebalancing the dynamic muscular forces about the shoulder combined with joint contracture release and ultimate glenohumeral joint morphology. It has been well documented that patients with persistent shoulder imbalance have a significant risk for progressive glenohumeral joint dysplasia, with increasing glenoid retroversion and posterior humeral head subluxation. Theoretically, this may be attributed to muscle imbalance about the shoulder as the vast majority of patients with persistent obstetrical brachial plexus palsy have quite strong internal rotators of the shoulder. This study revealed that the latissimus and teres major tendon transfers improved function and halted the progression of glenohumeral joint dysplasia. However, the improvements in glenohumeral dysplasia were quite modest. The authors do make note that during normal growth and development glenoid version progresses from approximately 7 degrees of retroversion at birth to 1 degree by 10 years of age. Therefore, a component of the improvement in glenohumeral joint version may be related to normal development. The authors recommend that tendon transfers with or without soft tissue releases be considered in patients who exhibit early radiographic evidence of glenohumeral joint dysplasia even to a mild degree in order to halt progressive deformity and improve shoulder function.
Journal of Bone and Joint Surgery