Background: Diaphyseal tibial fractures are the most frequent bone fractures in the body and are usually treated with intramedullary nailing method. However, this approach is responsible for 41% of the rotational deviation. 
Objectives: This study aimed to provide a radiographic evaluation method to determine tibial malrotation in closed fixation of tibia bone fractures during or after the operation.
Methods: This study was conducted in a university hospital from May 2015 to March 2016. All patients referring to the hospital with the complaints of minor trauma around the ankle and knee requiring radiographic evaluation of both joints were enrolled in the study. The inclusion criteria included being 20 and 50 years old; having normal axial, sagittal, and coronal lower limb alignment; lacking previous lower limb injury (such as fractures of the tibia or fibula), ankle or knee sprain; not having previous lower limb surgery, metabolic or congenital bone diseases, or malignancy. In all cases, a standard Anteroposterior (AP) radiograph of the knee was taken, and then, without changing the limb position or image setting, an AP radiograph of the ankle was obtained. The overlap between the distal tibia and fibula was measured in the PACS program environment.  
Results: Fifty cases were included in this study. The Mean±SD ages of males and females were 29.08±2.49 years and 31.46±2.04 years, respectively. The range of distal tibia-fibula overlap one centimeter above the tibiotalar joint line was 7.81 to 9.09 mm (confidence interval of 95%), and its percentage to the fibula shaft width at the same level was 49.43% to 54.35%.
Conclusion: According to the results, distal tibia-fibula overlap when the knee is in the true AP position, regardless of the side and gender, is 7.81 to 9.09 mm or 49.43% to 54.35%.