Surgical Treatment of Proximal Humerus Unicameral Bone Cyst: A Case Report.

Unicameral bone cysts (UBCs) are noncancerous, fluid-containing sacs commonly seen in the metaphysis of long bones among young individuals, mainly affecting the proximal humerus and femur. Since they are painless, 80% of patients do not experience any symptoms from UBCs unless it is complicated by a pathological or stress fracture. These patients usually present with no history of trauma, with mild pain, local tenderness, and occasionally swelling. The diagnosis of UBCS can either be an incidental finding or can be made with the help of clinical features, radiographs, and differential diagnoses of UBCs like aneurysmal bone cyst, fibrous dysplasia, enchondroma, eosinophilic granuloma, and intraosseous ganglia can be ruled out. While identifying these cysts is often straightforward, there is ongoing debate regarding the optimal management approach. We report a case of a 16-year-old female with proximal humerus UBC who presented with a pathological fracture of the right proximal humerus. The patient was initially managed conservatively. However, she sustained a refracture at the same site twice over four years. Due to fracture recurrence and residual deformity, it was treated surgically with curettage, bone grafting, and internal fixation. The normal alignment and function of the right upper limb were restored postoperatively.