Outcomes of scapula stabilization in obstetrical brachial plexus palsy: a novel dynamic procedure for correction of the winged scapula.

Among the late consequences of obstetrical brachial plexus palsy is winging of the scapula, a functional and aesthetic deformity. This article introduces a novel surgical procedure for the dynamic correction of this clinical entity that involves the dynamic transfer of the contralateral trapezius muscle and/or rhomboid muscles and anchoring to the affected scapula. In more severe cases of scapula winging, the contralateral latissimus dorsi muscle may also need to be transferred to achieve dynamic scapula stabilization. The outcomes of this novel surgical procedure were analyzed in relation to the effect on abduction, external rotation, growth of the scapula, and distance of the scapula from the posterior midline. The results were analyzed in 26 patients who underwent this procedure and had adequate follow-up. The mean patient age was 6.39 years. Fourteen (54 percent) had a diagnosis of Erb palsy, and 12 (46 percent) had a diagnosis of global paralysis. All 26 patients had an additional secondary procedure performed prior to or simultaneously with the scapula stabilization procedure. In 19 patients, the contralateral trapezius was transferred and anchored to the medial border of the winged scapula alone, but in seven cases the underlying rhomboid major was transferred along with the trapezius muscle to provide sufficient scapula stabilization. In five cases in which the scapula winging was severe, the contralateral latissimus dorsi muscle was transferred at a second stage. After this procedure, all patients demonstrated improved scapula symmetry. The mean increase in abduction was 18 degrees (p < 0.001), the mean increase in external rotation was 19 degrees (p < 0.001), and the mean increase in anterior flexion was 12 degrees (p = 0.015). The improvement of the relative position of the winged scapula on the posterior thorax was analyzed by measuring the distance of the inferior angle of both scapulae from the midline, then calculating the difference between normal and affected sides and comparing this value before and after the scapula stabilization procedure. This value preoperatively was 3.24 cm; postoperatively it decreased to 0.36 cm (p < 0.001), demonstrating a statistically significant improvement.