Recently, there are some reports of arthroscopic treatment for snapping scapula. We presented snapping scapula with twice arthroscopic treatment. [Case] A 21-year-old woman. She noticed snapping of her left scapula as a flag-bearer of her high school's marching band at the age of 16. Since then, flexion or abduction of her left shoulder within the range of 80-90 degrees caused painful snapping. Imaging studies did not demonstrate any deformity or tumor of the scapula, but incongruity between the scapula and the chest wall was detected by an MRI. To improve the functional disability of the scapulothracic joint, she received conservative therapy. She did not respond to conservative treatment and she felt dysesthesia of the upper extremities like a thoracic outlet syndrome.She underwent arthrosopic bursectomy at the age of 19. The operation finding was mild bursitis. Snapping was relieved by the surgery. 2 months later, when she tried to lift a heavy box, she felt ripping sensation within the scapulothracic joint and painful snapping relapsed. At the age of 21, an ultrasonography showed a nodule which seemed to be involved with snapping. Therefore arthroscopic surgery was performed again. The scapulothracic joint was covered with white scaring tissue which we removed. We also resected the bone edge surrounding superomedial angle of the scapula. The pathological finding of scaring tissue was scattered elastic fibers characteristic of elastofibroma, pseudo-tumor thought to be the result of mechanical stimulations under some genetic background. This case was guessed to be the state on the way to elastofibroma. 6 months after the surgery, she retuned to her school with the symptoms relieved. Arthroscopic treatment was effective for this snapping scapula. However, we think that more clearly defined indications for and contraindications against surgery are required.This case suggests that snapping scapula is a stimulator of elastofibroma formation.
