Lilly Ryan J, Koueiter Denise M, Graner Kelly C, Nowinski Gregory P, Sadowski Jason, Grant Kevin D
Department of Orthopaedic Surgery, Beaumont Hospital, Royal Oak, MI, United States.
Department of Orthopaedic Surgery, Beaumont Hospital, Royal Oak, MI, United States.
Injury. 2018 Feb;49(2):345-350. doi: 10.1016/j.injury.2017.12.006. Epub 2017 Dec 7.
Lag screw cutout is one of the most commonly reported complications following intramedullary nail fixation of intertrochanteric femur fractures. However, its occurrence can be minimized by a well-positioned implant, with a short Tip-to-Apex Distance (TAD). Computer-assisted navigation systems provide surgeons with the ability to track screw placement in real-time. This could allow for improved lag screw placement and potentially reduce radiation exposure to the patient and surgeon.
Between Oct 2014 and Jan 2016, patients with intertrochanteric femur fractures being treated with intramedullary nail fixation by one of three fellowship-trained orthopaedic traumatologists were enrolled. Inclusion criteria were low-energy mechanism of injury and fracture class 31-A1/A2. Open fractures and patients with multiple injuries to the lower extremity were excluded. Patients were randomly assigned to computer-assisted navigation or a conventional fluoroscopic technique for lag screw placement. The primary outcomes were TAD, measured by postoperative anteroposterior and lateral x-rays by an independent reviewer, and radiation exposure measured in seconds of fluoroscopy time. Surgical time was also recorded.
50 patients were randomized, 26 to the computer-assisted navigation group and 24 to the control group. The mean manually-measured TAD in the computer-assisted navigation group was 14.1mm±3.2 and in the control group was 14.9mm±3.0 (p=0.394). There was no difference between groups in total radiation time (navigation: 58.8 s±23.6, control: 56.5 s±28.5, p=0.337) or radiation time during lag screw placement (navigation: 19.4 s±8.8, control: 18.8 s±8.0, p=0.522). The surgical time was significantly longer in the computer-assisted navigation group with a mean surgical time of 45.8min±9.8 compared to 38.4min±9.3 in the control group (p=0.009).
Computer-assisted navigation consistently produced excellent TADs, however it was not significantly better than conventional methods when done by fellowship-trained orthopaedic traumatologists. Surgeons with a lower volume trauma practice could potentially benefit from computer-assisted navigation to obtain better TAD.
拉力螺钉穿出是股骨转子间骨折髓内钉固定术后最常报道的并发症之一。然而，通过植入位置良好、尖顶距（TAD）短的植入物可将其发生率降至最低。计算机辅助导航系统使外科医生能够实时跟踪螺钉置入情况。这可能会改善拉力螺钉的置入，并有可能减少患者和外科医生所受的辐射暴露。
2014年10月至2016年1月期间，纳入了由三名接受过专科培训的骨科创伤外科医生之一采用髓内钉固定治疗的股骨转子间骨折患者。纳入标准为低能量损伤机制和31 - A1/A2级骨折。开放性骨折和下肢多处损伤的患者被排除。患者被随机分配至计算机辅助导航组或传统透视技术组进行拉力螺钉置入。主要结局指标为TAD（由独立评估者通过术后前后位和侧位X线测量）以及透视时间（以秒为单位）测量的辐射暴露。还记录了手术时间。
50例患者被随机分组，26例进入计算机辅助导航组，24例进入对照组。计算机辅助导航组手动测量的平均TAD为14.1mm±3.2，对照组为14.9mm±3.0（p = 0.394）。两组在总辐射时间（导航组：58.8 s±23.6，对照组：56.5 s±28.5，p = 0.337）或拉力螺钉置入期间的辐射时间（导航组：19.4 s±8.8，对照组：18.8 s±8.0，p = 0.522）方面无差异。计算机辅助导航组的手术时间明显更长，平均手术时间为45.8min±9.8，而对照组为38.4min±9.3（p = 0.009）。
计算机辅助导航始终能产生优异的TAD值，然而，由接受过专科培训的骨科创伤外科医生操作时，其并不比传统方法显著更优。创伤手术量较少的外科医生可能会从计算机辅助导航中获益，以获得更好的TAD值。
