Introduction and Aims: A retrospective review of the medical records and radiographs of patients treated with operative fixation of two-part proximal humerus fractures was undertaken to compare the results of different modes of fixation. Comparison was made between ORIF with a blade plate, percutaneous Kirschner wire fixation, and intramedullary nail fixation utilising a Polarus nail.

Method: Thirty-six patients were treated with intramedullary fixation, 11 with blade plate fixation and 10 with percutaneous fixation, utilising Kirschner wires. Union rates were 34/36 (94%) for the Polarus nail, 9/10 (90%) for K-wire fixation and 9/11 (82%) for blade plate fixation. Time to union averaged 12.4 weeks for the Polarus nail, 11 weeks for K-wire fixation and 21 weeks for blade plate fixation. Average active shoulder range of motion in forward flexion/abduction were 125/118 degrees for intramedullary nail, 132/132 degrees for the blade plate and 112/111 degrees for patients treated with K-wire fixation.

Results: The major discrepancy in comparison of the different modes of fixation was in the complication rate. Ten complications occurred in the group treated with intramedullary fixation. These included one non-union, one painless fibrous non-union and back out of the proximal interlocking screw in eight patients, five of which required screw removal. Seven of 11 patients treated with blade plate fixation experienced complications, including two non-unions, two malunions, two with functionally limiting heterotopic ossification, one arthrofibrosis and one with persistent pain. The complications associated with percutaneous Kirschner wire fixation included one non-union, two malunions, four developed functionally limiting heterotopic ossification, five incidences of early pin removal secondary to pin migration, one arthrofibrosis requiring surgical intervention and one infection requiring surgical irrigation and debridement.

Conclusion: Results comparable in all groups. Fewer complications seen with intramedullary fixation. Majority of complications with Polarus nail related to backing out of proximal interlocking screw. Modification of implant to include end cap, which locks the proximal screw seems to eliminate complication. Results indicate that intramedullary nail fixation is superior to blade plate fixation or pecutaneous Kirschner wire fixation for two-part proximal humerus fractures.