Objective To evaluate the clinical effect of the intertrochanteric fractures with or without lateral femoral wall fractures using proximal femoral nail antirotation (PFNA).Methods From May 2008 to June 2011,102 patients with intertrochanteric fractures were treated with PFNA.In accordance with the preoperative three dimensional CT reconstruction(3D CT) images,the group A included 41 cases with lateral femoral wall fractures,and the other 61 cases with an intact lateral wall were in group B.According to the AO/OTA classification,there were 5 cases in 31-A2,36 in 31-A3 in group A,and 61 in 31-A2 in group B.The operative time,operative blood loss,average length of stay,postoperative X-ray images,and 3D CT images were collected for each patient.Time of partial weight-bearing,full weight-bearing and fracture healing were also recorded.Clinical evaluation was made using the functional recovery scale (FRS) of hip fractures.Results The mean operation time was 56±8 min in group A vs 45±6 min in group B; the mean blood loss was 238±21 ml vs 175±11 ml; the average length of stay was 17±3 days vs 15±3 days.On the postoperative radiography,the blowout of lateral trochanteric wall only occurred in 8 (19.5％,8/41) cases in group A and 3 (4.9％,3/61) in group B.According to the postoperative 3D CT,the similar findings were seen in 36 (87.8％.36/41) cases in group A and 45 (73.8％,45/61) in group B.Eighty-two cases were followed up for 6 to 35 months (mean.19.5 months).The mean FRS score was 64.2±4.8 points in group A and 76.5±7.9 points in group B.Conclusion When treating unstable intertrochanteric fractures,iatrogenic fractures in lateral trochanteric wall could be easily caused with using PFNA.3D CT could effectively evaluate iatrogenic trauma in the intertrochanteric fractures.