CT scan to measure fracture malrotation after interlocking intramedullary nailing of femoral fracture / 中国矫形外科杂志

ABSTRACT

Objective To measure the extent of malrotation of femur fractures with CT scan after fixation with interlocking intramedullary nailing , and to discuss the methods which can help to correct the malrotation of femur fracture during the operation. MethodWith CT scan, the anteversion of femur fracture after the close reduction and fixation with interlocking intramedullary nailing in 56 cases was measured, and the difference of anteversion between the fracture side and the contralateral side was evaluated. The increase of anteversion represented internal rotation of the distal fragment, whereas the decrease of anteversion meaned external rotation. According to AO classification system, the type A of infratrochanteric fractures happened in 9 cases, type A of femoral shaft fractures happened in 12 cases, type B in 15 cases,type C in 7 cases,and 13 cases of femoral supercondyle fractures were type A. ResultThe results of measurement showed that the femoral anteversion after fixation with interlocking intramedullary nailing was changed in all patients. The anteversion of the femoral shaft fracture ranged from 13.35?to 47.21?. The aneversion of infrotrochanteric fractures ranged from -7.12?to 36.35?, and the supercondyle fracture of femur from -11.10?to 39.22?. For the extent of malrotation of distal femoral fracture, the internal rotation was more obvious than the external rotation. The number of Internal rotation cases accounted for 60.71%, and the external cases accounted for 39.29%. The maximum internal malrotation happened in femoral shaft fracture, from 1.37?to 29.82?with average malrotation 12.34?. and the minimum internal malrotation happened in infratrochanteri fracture, from 0.81?to 23.21?,with the average malrotation 8.32?. The medium internal malrotation was femoral supercondyle fracture, from 1.72?to 27.11? with the average malrotation 8.38?. The maximum external malrotation happened in femoral shaft fracture, from 1.11?to 21.12?with the average of them 9.33?. The minimum external malrotation happened in infratrochanteri fracture, from 1.31?to 16.23?with the average 7.71?. The medium external malrotation was seen in femoral supercondyle fracture, from 0.97?to 17.96?with average 8.22?. For these three parts of femoral fracture, the partnership T test was done between the fracture side and the contralateral side, the results showed that there were significant differences among of them,P