Management of a Massive Acromioclavicular Joint Cyst: The Geyser Sign Revisited

Acromioclavicular (AC) joint cysts can occur secondary to rotator cuff athropathy. These can cause both symptoms and cosmetic impairment. We describe the first reported case of complete and spontaneous resolution of a massive AC joint cyst secondary to rotator cuff athropathy. The current guidelines for treatment involve surgical intervention, including arthrodesis, joint debridement and arthroplasty depending on the patients demand and co-morbidities. Each carries its own risk of potential complication, which is clearly not the case with non-operative management. Within the guidelines, there is no recommendation for conservative treatment; however, given the inevitable potential risk of surgery, we would strongly support a trial of conservative treatment before resorting to surgery.