Risk factors for malunion of distal tibia fractures treated by intramedullary nailing

Background The treatment of distal tibia fractures (DTF) has historically been a difficult challenge for orthopedic surgeons because of the particular characteristics of this anatomical region. Intra medullary nailing (IMN) remains the best treatment option. However, achieving and maintaining perfect reduction and stable fixation with IMN can be technically challenging due to the large medullary cavity within a short distal fragment. The aim of our study is to determine the risk factors for malunion in DTF treated with IMN. Methods It is a retrospective study including DTF treated surgically by IMN in the Orthopedics and Trauma Department at a tertiary hospital over a period of 7 years. The quality of reduction was evaluated by radiological assessment of the antero-posterior (AP) and lateral views of the tibia and ankle at the last follow-up. Results Our series included 90 patients with an average age of 44.8 years. Sex-ratio was 2.6. Tobacco use was reported in 35.6% of the patients. Diabetes was present in 11.1% of the patients, and 12.2% of them had open fractures. According to the OTA/AO classification, the majority of injuries were classified as type A1 (76.7%). Fibula fractures were present in 86.7% of cases. The mean follow-up was 48 months. Malunion occurred in 13 cases. Based on the univariate analysis, smoking and dynamic fixation were significantly associated with malunion. In the multiple logistic regression analysis, dynamic fixation was found to be a significant factor that increased the risk of malunion by 7.5 times. Conclusion Neither patient demographics nor fracture characteristics were risk factors for malunion. Nevertheless, it should be noted that dynamic nailing must be avoided as it is associated with a higher risk of malunion. Furthermore, one to two medial to lateral distal locking screws provide sufficient stability without the need for additional fibular fixation. Trial registration Not applicable.