Posterior shoulder dislocation associated with fracture of the humeral anatomic neck: treatment guidelines and long-term outcome.

OBJECTIVE: We describe here 10 cases of posterior shoulder dislocation associated with fracture of the humeral anatomic neck.
METHODS: Patients were treated according to our uniform treatment guidelines, in which only the dislocated humeral head (closed, if possible) was reduced, without any concomitant repositioning or internal fixation for fractures.
RESULTS: Reduction resulted in an acceptable repositioning of the fractured fragments in all but one case. Anatomic neck fractures were impacted by applying longitudinal pressure for stabilization. Although early physiotherapy was initiated, redisplacement of the bone fragments did not occur. Of nine patients who were followed for more than 2 years, complete recovery of function was achieved in all but two patients. The completely detached humeral head became avascular necrotic accompanied by subchondral collapse in one case, and in the other case the displaced lesser tuberosity caused a decreased range of movement.
CONCLUSION: We recommend initially treating such patients by either open or closed reduction of the dislocated humeral head and impaction of the fracture, with neither repositioning nor internal fixation of any of the fractured fragments. A completely detached humeral head or bone fragments displaced more than 10 mm after reduction of the dislocated humeral head contraindicate the use of this method.