Posterior shoulder dislocation associated with proximal humeral comminuted fracture

Posterior shoulder dislocation associated with proximal humeral comminuted fracture is rare. The posterior dislocation component is usually hidden behind comminuted fracture and not easy to be detected in routine roentgenogram. Comminuted proximal humeral fracture will cause patients to experience too much pain to receive a thorough physical examination, which can make this type of injury more frequently neglected. We present three cases of posterior shoulder dislocation associated with proximal humeral comminuted fracture. The components of the posterior shoulder dislocations were initially neglected, which led to late sequelae in the first case, reoperation in the second case, and a change of operation planning in the third case. Computed tomography is valuable in preoperative planning and detection of posterior dislocation. If it is not available, good patient positioning on the operation table with full access to a fluoroscopic guide is another way to detect posterior dislocation component. Since this type of injury is rare and easily neglected, orthopedic surgeons should have a high clinical suspicion in daily practice so as to avoid misdiagnoses.