Comminuted humeral head fractures: a multicenter analysis.

Three centers' experience with 93 comminuted humeral head fractures were clinically (Constant score) and radiologically (Neer) analyzed. The results revealed fundamental differences between the various types of fractures depending on the number of fragments. For three-part fractures open reduction and internal fixation (mean Constant scores 83 and 91 points, respectively) or conservative treatment (78 points) seem to be indicated. The prognosis for four-part fractures is determined largely by the vascular supply of the head fragment with a high risk of humeral head osteonecrosis. For this reason primary prosthetic replacement (mean Constant score, 74 points compared with 54 points for conservative treatment and 52 points for open reduction) should be recommended for this type of fracture. In conclusion, we stress the importance of fracture type directing the therapeutic modality.