Imaging risk factors for predicting postoperative complications of intramedullary nailing for tibial fracture

Abstract

Abstract Objective The objective of this study was to analyze the ratio of fracture site diameter to tibial isthmus diameter (RFTI) as a predictor of postoperative complications, including malunion and delayed union, after tibial intramedullary nailing for middle and lower tibial fractures. Methods Data were collected from all adult patients older than 20 years of age who underwent tibial intramedullary nailing for middle and lower tibial fractures between January 2015 and January 2022 and were followed up for at least 1 year. Diabetes history, smoking history, fracture type, injury mechanism, surgical method, surgical approach, diameter of the medullary cavity at the fracture site, and diameter of the tibial isthmus were recorded. Logistic regression analysis was used to determine the variables affecting the occurrence of complications. RFTI was used to calculate the sensitivity and specificity of the parameters, and ROC curves were generated to establish RFTI thresholds for predicting complications. Results A total of 123 patients with middle and lower tibial fractures were treated with intramedullary nails. The mean age of the patients was 43.72 years (range, 21–81 years); 89 were males and 34 were females. Univariate logistic regression analysis showed that fracture type, open reduction surgery, superior patellar approach, and RFTI value were significantly correlated with postoperative complications after intramedullary nailing of a tibial fracture. Multivariate logistic regression analysis showed that the RFTI value was an independent risk factor for complications (P = 0.001*). By using the RFTI values as predictors of complications, a ROC curve was generated to establish a threshold. The ROC curve showed that a RFTI value ≥ 1.31 had a sensitivity of 0.89, a specificity of 0.71 and an area under the ROC curve of 0.82 for predicting complications. Conclusions The results of this study suggest that a wider intramedullary diameter and a shorter fixed length at the fracture site are associated with a higher incidence of complications after tibial intramedullary nailing. The RFTI value may be used as a reliable parameter for predicting complications after such surgery. For patients with a high RFTI (≥ 1.31), additional reduction and fixation techniques may be required to obtain and maintain fracture reduction.