Displaced three- and four-part proximal humerus fractures: evaluation and management.
Three- and four-part fractures are the most severe injuries in the spectrum of fractures of the proximal humerus. Despite the shortcomings of the currently available imaging techniques, fracture displacement remains an important principle in guiding management. As a result, increasing emphasis has been placed on the use of Neer's criteria in intraoperative decision making. Patients with four-part fractures with valgus impaction of the head fragment should be treated with limited open reduction and minimal internal fixation, as the blood supply to the humeral head is better preserved than with other fracture patterns and the potential for osteonecrosis is less. In the case of displaced three- and four-part fractures, the physiologic age and bone quality also help guide treatment selection. In young patients with good bone quality, attempts to preserve the humeral head by meticulous handling of soft tissues and the use of low-profile implants to secure fracture fragments is recommended. Vertical fixation alone with Rush rods in patients with poor bone quality and in those with four-part fractures is no longer considered adequate and should not be used. For selected patients with three-part fractures and satisfactory bone quality, fixation with Ender rods and tension-band wiring may be appropriate. Elderly patients and those with poor bone quality have a greater risk of loss of reduction after open reduction and internal fixation, and the current consensus is that early hemiarthroplasty is the appropriate treatment. Late reconstruction necessitated by malunion and soft-tissue contracture is technically difficult, and the outcome is less favorable. The outcome of treatment of three- and four-part fractures is dependent on the surgeon's ability to analyze the fracture pattern and execute appropriate techniques to restore anatomy and function. The use of cement for prosthetic fixation and rigorous attention to tuberosity stabilization and anatomic reduction are two factors that will optimize outcome. Adequate pain relief after hemiarthroplasty has been consistently demonstrated, but return of motion and function is less predictable.