[Related factors of revision of distal femoral fractures treated with lateral locking plate]

OBJECTIVE: To analyze the factors related to the need for revision surgery due to nonunion or internal fixation failure after the treatment of distal femoral fracture with lateral locking plate (LLP). METHODS: Retrospective analysis was made of the clinical data of 130 cases with distal femoral fracture treated in our hospital from March 2005 to March 2019. SPSS 17.0 software (univariate analysis and Logistic regression analysis) was used to analyze the general condition [gender, age, body mass index (BMI), comorbidities, smoking history], injury related factors (energy of injury, open or closed injury, AO/OTA classification of fracture, fracture area distribution), operation related factors (operation time, reduction quality, postoperative infection) and construct characteristics of internal fixation. RESULTS: Twelve of 130 patients who were included in the study underwent revisional surgery, with a revision rate 9.2%. Univariate analysis showed that there were significant differences in age, BMI, AO/OTA classification, fracture area distribution, operation time, reduction quality, length of plate/fracture area, length of plate/fracture area above condylar between the two groups (P < 0.05). Logistic regression analysis showed that AO/OTA classification (A3), supracondylar involved fracture, operation time, reduction quality and the length of the plate/fracture area above the condylar were the possible related factors (P < 0.05). Destruction of the medial support ability of the femur in comminuted type A3 fracture, supra-condylar cortex area fracture involvement, increase of the bending stress of the LLP due to poor fracture reduction quality, damage of the blood supply of fracture end due to long-time operation, and stress concentration caused by insufficient length of plate might be risk factors of revisional operation after the treatment of distal femoral fracture with LLP. For the patients who needed revision after LLP treatment, additional use of medial minimally invasive plate fixation and autologous bone transplantation, change to intramedullary nail fixation were commonly used clinical treatment strategies. CONCLUSION: AO/OTA classification (A3), supracondylar involved fracture, long operation time, poor reduction quality and the length of the plate/fracture area above the condylar were the possible predictive factors of the revision in distal femoral fractures treated with lateral locking plate. The appropriate application of the locking plate and operation strategy are the key to reduce the revision rate in distal femoral fractures.