To investigate the surgical outcomes of patients with femoral mid-diaphyseal fractures treated with minimally invasive plate osteosynthesis (MIPO), which were difficult to intramedullary nailing.

We evaluated 11 patients with femoral mid-diaphyseal fractures who were treated with MIPO. There were 7 males and 4 females and the mean age was 47 years (20-85 years). According to AO/OTA classification, there were 1 type of A1, 5 types of A3, 1 of B2 and 4 of B3. The reason of plate fixation instead of intramedullary nailing is as follows: femoral vessel and severe soft tissue injuries-2 cases, polytrauma patients with chest injury-6 cases, and narrow medullary canal diameter-3 cases. Six out of 11 cases were treated with initial external fixation as a damage control orthopedics.

The mean union time of 6 cases was 3.7 months (3-5 months). There were 5 cases (45%) of nonunion, which should be treated with autogenous bone graft. All cases of nonunion resulted from severe soft tissue damage and polytrauma, which needed initial external fixation. There was no case of malalignment and implant-related complication.

In cases of difficult intramedullary nailing for the femoral mid-diaphyseal fractures, MIPO could be an alternative surgical option, but concurrent soft tissue injuries and multiple trauma may increase the risk of nonunion in spite of biological fixation.