Significance of Tip Apex Distance in Intertrochanteric Fracture femur managed with Proximal femoral nailing

Abstract

IntroductionTip Apex distance (TAD) is well established method of prediction of outcome in intertrochanteric fractures managed by Dynamic Hip Screw. This retrospective study was done to assess the significance of Tip Apex Distance in the management of the intertrochanteric fractures by Proximal femoral nail. Material and methodsThe study was done in a tertiary care centre where 174 follow-up patients operated for intertrochanteric fractures with proximal femoral nail were included in the study. The radiological outcome of patients was assessed using the neck shaft angle, neck length and the offset whereas the functional status was assessed using the Harris hip score and the Lower extremity functional scoring system. These functional and radiological outcomes were compared with the TAD for any significant findings. ResultsThe tip apex distance on the postoperative X-ray was found to be 22.93+3.88mm. The Lower Extremity Functional Score was found to be 70.71+8.153. The Harris Hip Score was found to be 85.408+9.586. Change in the neck length as compared to the uninjured hip was found to be 1.46+1.705. Change in the offset and neck shaft angle was 1.38+1.567 and -2.61+1.27 respectively. There were 8 cases of screw cut out and 8 cases of superficial infection. DiscussionThe Harris hip score and the LEFS increased with decreasing values of the Tip Apex distance. The Neck shaft angle, Neck length and the offset all decreased with the increase in the Tip Apex Distance. The Harris hip score and the LEFS decreased with the decrease in the Neck shaft angle, Neck length and the offset. On examining the 2 groups one with TAD <25mm and the other with TAD >25mm it was seen that both functionally and radiologically, the outcome was better in the group having TAD<25mm. ConclusionThis study indicates that the Tip Apex Distance can be used as a useful predictor of the outcome of the proximal femoral nail in intertrochanteric fractures. Level of evidenceIV.