A comparison of locking versus nonlocking plates in distal femur fractures

Comminuted distal femur fractures are associated with a high complication rate and their treatment is difficult. This type of fracture is more common in young people with major trauma and following motor vehicle accidents. In old patients with osteoporosis the fractures are often closed and occur following a minor trauma. The aim of our study was to compare the outcomes and complications of treatment of intra-articular distal femur fractures using locking and nonlocking condylar buttress plates. In this retrospective study, 79 patients undergoing surgery due to type C distal femur fractures (T or Y condylar fracture) from 2008-2010 were included. Patients with comorbidities such as diabetes or end stage diseases and patients with other lower extremity fractures on the same side were excluded. For each patient demographic data including age, sex, mechanism of injury, and type of injury was collected. All patients were followed for at least one year postoperatively for complications such as infection, non-union, and malunion. In this study 58 patients (73%) were male and 21 (23%) female. The mean age of the locking group was 37.4 ± 17.3 years and the nonlocking group 40.6 ± 17.3 years. There were no significant differences between the two groups in age and sex. In the locking group 36 patients (80%) had closed fractures and 9 (20%) open fractures and in the nonlocking group 25 patients (73.4%) had closed fractures and 9 (26.6%) open fractures. In both groups 5 patients had infections (11.1% in the locking group and 14.7% in the nonlocking group) and two patients each had nonunion (4.4% and 5.9% respectively). In the locking group 4 patients (8.9%) and in the nonlocking group 6 patients (17.6%) had plate failure. In our study the effects of treatment with both locking and nonlocking condylar buttress plates regarding infection and nonunion were similar but malunion and plate failure were higher in the nonlocking group. Nonetheless, this difference was not statistically significant.