Hoffa fracture associated with ipsilateral femoral shaft fracture: clinical feature and treatment.

Hoffa fracture associated with ipsilateral femoral shaft fracture is very rare. Three cases of this rare type of injury were retrospectively reviewed. The sites of femoral shaft fractures and Hoffa fractures were documented. All femoral shaft fractures were managed with internal fixation. The rate of misdiagnosis for the Hoffa fractures was documented. Functions of the affected knees were evaluated according to the modified Hospital for Special Surgery (HSS) scores at two years follow-up. Femoral fractures were either transverse or composite in all three cases. Ipsilateral Hoffa fractures occurred at medial condyle in two cases, and lateral condyle in one case. Only one Hoffa fracture was identified preoperatively. All the femoral shaft fractures healed uneventfully. In the patient whose Hoffa fracture was correctly diagnosed, the modified HSS score was 94. In another patient, whose Hoffa fracture was treated by a second operation, the modified HSS score was 93. And in the third case, who refused additional operation for the Hoffa fracture, the modified HSS score was only 70. Conclusively femoral shaft fracture can be associated with ipsilateral Hoffa fracture, especially in motorcycle accident. This type of injury is very rare and misdiagnosis is common.