: The present study compared a 3-dimensional computed tomography 3DCT classi cation Nakano classi cation with conventional x-ray classi cations Jensen classi cation and AO classi cation in 44 patients with trochanteric femoral fractures, and evaluated the patterns of fracture lines using 3DCT images. The concordance rate between the Jensen and 3DCT classification, and between the AO and 3DCT classification was 65.9 and 75.0 , respectively. 3DCT scans enabled the creation of detailed images of fracture lines. The anterior fracture line was found to run along the intertrochanteric crest in 90.9 of patients, while the location of the posterior fracture line was in the same approximate position in all patients, including those with comminuted fractures 34.1 . Posterior destruction along lateral fracture lines was present in 63.6 of patients. Furthermore, the preoperative and postoperative CT images of 33 patients with fractures treated via insertion of short femoral nails demonstrated that there was dif culty reducing greater trochanteric fractures. This included reducing fracture sites separated by nail insertion 42.4and greater trochanteric fracture sites displaced after surgery 54.5 , suggesting that the use of short femoral nails is limited.