BACKGROUND Intertrochanteric femoral fractures are prevalent among the elderly, and usually demands surgical treatments. Proximal femoral nail antirotation Asian version (PFNA-II) is widely used for intertrochanteric fracture treatment. The computer-assisted preoperative planning (CAPP) system has the potential to reduce the difficulty of PFNA-II in the treatment of intertrochanteric fractures. The aim of the study was to investigate and compare the learning curves of PFNA-II treatment with CAPP and conventional preoperational planning methods for intertrochanteric femoral fractures. METHODS A total of 125 patients with intertrochanteric fracture who were treated with PFNA-II between March 2012 and June 2015 were retrospectively analyzed. Patients who underwent surgery with CAPP procedure by a junior surgeon were regarded as group A (n = 53); patients who underwent the conventional surgery by another junior surgeon were regarded as group B (n = 72). Each group was divided into three subgroups (case 1-20, case 21-40, case 41-53 or case 41-72). RESULTS The average operation time of group A was 45.00(42.00, 50.00) minutes, and in group B was 55.00 (50.00, 60.00) minutes (P < 0.01). Average radiation frequency and blood loss were 13.02 ± 2.32, 160.00 (140.00, 170.00) ml and 20.92 ± 3.27, 250.00 (195.00, 279.50) ml, respectively, with significant differences (P < 0.01). The learning curve of the surgical procedure in group A was steeper than that in group B. There were no significant differences in patient reported outcomes, hospital stay and complication rate between the two groups. Significant differences were observed between group A and B in Harris score at last follow-up in the AO/OTA type 31-A2 intertrochanteric fracture (P < 0.05). CONCLUSION Compared with conventional preoperative planning methods, CAPP system significantly reduced operation time, radiation frequency and blood loss, thus reshaped the learning curve of PFNA-II treatment with lower learning difficulty. TRIAL REGISTRATION researchregistry4770. Registered 25 March 2019.

中文翻译：

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计算机辅助的术前计划可改善股骨粗隆间股骨骨折的PFNA-II学习曲线。

背景技术转子间股骨骨折在老年人中很普遍，并且通常需要手术治疗。股骨近端抗旋转亚洲版（PFNA-II）被广泛用于股骨转子间骨折的治疗。计算机辅助的术前计划（CAPP）系统有可能减少PFNA-II在股骨转子间骨折治疗中的难度。本研究的目的是研究和比较PFNA-II与CAPP的治疗曲线以及股骨粗隆间股骨骨折的常规术前计划方法。方法回顾性分析2012年3月至2015年6月行PFNA-II治疗的125例股骨转子间骨折患者。由初级医生进行了CAPP手术的患者被视为A组（n = 53）。由另一位初级医生进行常规手术的患者被视为B组（n = 72）。每个组分为三个子组（案例1-20，案例21-40，案例41-53或案例41-72）。结果A组的平均手术时间为45.00（42.00，50.00）分钟，而B组的平均手术时间为55.00（50.00，60.00）分钟（P <0.01）。平均辐射频率和失血量分别为13.02±2.32、160.00（140.00、170.00）ml和20.92±3.27、250.00（195.00、279.50）ml，差异有统计学意义（P <0.01）。A组的外科手术学习曲线比B组更陡。两组患者报告的结局，住院时间和并发症发生率均无显着差异。在最后一次随访中，AO / OTA型31-A2转子间骨折A组和B组在Harris评分方面存在显着差异（P <0.05）。结论与常规术前计划方法相比，CAPP系统显着减少了手术时间，辐射频率和失血量，从而重塑了PFNA-II治疗的学习曲线，学习难度较低。试用注册researchregistry4770。注册于2019年3月25日。