Restoration of Normal Rotator Cuff Function after Successful Treatment of a Displaced Non-union of a Fracture of the Body of the Scapula

Abstract

No previous reports have identified the mechanical disadvantage created by scapular body fractures or quantified the improvement in cuff function achieved by restoration of the scapular anatomy. We report a displaced non-union of the scapular body in a veteran pentathlete with weakness and early fatigue of rotator cuff function. Electromyography and magnetic resonance imaging excluded denervation, tendon rupture or muscle scarring. Characteristic anteromedial displacement of the lateral column fragment caused shortening of the transverse diameter of the scapula and the effective length of cuff muscle. Isokinetic dynamometry quantified cuff weakness, particularly in internal rotation. Healing of the non-union was demonstrated following open reduction, internal fixation, and bone grafting. Isokinetic dynamometry quantified restoration of normal cuff function, and an excellent clinical outcome was achieved. We conclude that measurable deficits in cuff function may follow scapular body fractures. Operative management to union can restore normal scapular and rotator cuff function.