Unrecognized bony Bankart lesion accompanying a dislocated four-part proximal humerus fracture before surgery: a case report

Proximal humerus fractures are the third most common fractures, totaling 4% to 5% of all fractures. Here, we present the case of a 39-year-old man with a dislocated four-part fracture of the proximal humerus with a huge bony Bankart lesion. Preoperatively, the bony Bankart lesion of the glenoid was not visualized on computed tomography scans or magnetic resonance imaging because the fracture of the proximal humerus was comminuted, displaced, and complex. It was planned for only the humerus fracture to be treated by open reduction and internal fixation using a locking plate. However, a fractured fragment remained under the scapula after reduction of the dislocated humeral head. This was mistaken for a dislocated bone fragment of the greater tuberosity and repositioning was attempted. After failure, visual confirmation showed that the bone fragment was a piece of the glenoid. After reduction and fixation of this glenoid part with suture anchors, we acquired a well-reduced fluoroscopic image. Given this case of complex proximal humerus fracture, a glenoid fracture such as a bony Bankart lesion should be considered preoperatively and intraoperatively in such cases.