To produce smooth shoulder motion, the scapula must glide freely over the posterior thorax. Incongruence between the concave scapula and the convex thoracic wall, which can occur from anatomic predisposition, space-occupying skeletal lesions, fibrotic bursae, muscle imbalance, or a kyphotic posture, can produce painful crepitus and/or bursitis within the scapulothoracic articulation. While some patients are mildly symptomatic, others may complain of severe pain and poor shoulder function even with simple tasks.

The constellation of symptoms surrounding scapulothoracic crepitus or bursitis, commonly known as snapping scapula syndrome, can be classified according to the suspected cause. Excessive anterior angulation of the superomedial scapular angle or abnormal space-occupying lesions within the scapulothoracic space, such as elastofibromas, fibrotic bursae, or other osseous lesions, commonly result in mechanical crepitus. On the other hand, patients with scapular pain without mechanical symptoms are more likely to have symptomatic bursitis as a result of chronic overuse. However, this clear distinction is not commonly seen in clinical practice because mechanical crepitus can lead to symptomatic bursitis, and conversely, symptomatic bursitis can lead to mechanical crepitus. As a result, most patients have symptoms that may resemble both mechanical and nonmechanical origins.

Regardless of the etiology, current data support initial nonoperative management in patients with symptoms characteristic of scapulothoracic crepitus or bursitis. Surgical management is typically indicated after a trial of nonoperative treatment fails to result in symptomatic improvement. However, the thresh-old for early surgical intervention is lowered when an anatomic lesion capable of producing scapular snapping is identified on imaging studies because these patients are more likely to fail nonoperative treatment.

Scapulothoracic bursectomy with or without partial scapulectomy using an open, mini-open, or all-arthroscopic approach can result in considerable improvements in pain and function. However, several outcomes studies have shown that despite these improvements, many patients still suffer from continued pain and disability as evidenced by suboptimal clinical outcomes scores and marginal patient satisfaction ratings. Therefore, the purpose of this article is to review the current knowledge pertaining to snapping scapula syndrome and to identify areas of further research that may be helpful to improve clinical outcomes and patient satisfaction.

Full Article: Scapulothoracic Bursitis and Snapping Scapula Syndrome