Department of Orthopaedic Surgery, Lampang Hospital and Medical Educational Centre, Lampang, Thailand.
Hip Int. 2021 Jan;31(1):50-57. doi: 10.1177/1120700019873886. Epub 2019 Sep 4.
Malposition of the acetabular component mainly results from intraoperative pelvic motion and manual errors during cup placement. We investigated the outcomes of a device that uses a level indicator application of a smartphone to function as a pelvic tilt goniometer to assess intraoperative motion. The cup positions outside Lewinnek's safe zone were compared between the smartphone-assisted technique and the conventional method that uses a mechanical alignment guide.
A randomised controlled trial was conducted among 64 patients receiving primary cementless total hip arthroplasties (THAs) via a posterolateral approach from June 2015 to February 2017. Acetabular components were implanted either by conventional technique ( = 32) or using smartphone technique ( = 32). Inclination and anteversion angles were measured in supine pelvic radiographs.
The inclination angle in the smartphone group was not significantly different from the conventional group (41.2° ± 3.9° vs. 40.3° ± 7.9°, = 0.567). The anteversion angle was also similar (19.3 ± 3.8° vs 19.1° ± 5.9°, = 0.856). However, the standard deviation of the angle in the smartphone group was significantly lower for inclination (< 0.001) and anteversion (= 0.016). There were 3 outliers (9.4%) in the smartphone group, but 13 (40.6%) in the conventional group ( = 0.008). The risk ratio was 0.23 (95% CI, 0.07-0.73). The risk difference was -0.31 (95% CI, -0.51- -0.11).
The smartphone-assisted technique in THA improves the precision of cup placement and decreases the percentage of safe zone outliers.Thai Clinical Trials Registry (ID: TCTR20151123002).
髋臼部件的位置不当主要是由于术中骨盆运动和杯放置过程中的手动错误导致的。我们研究了一种使用智能手机水平指示器应用作为骨盆倾斜角度计的设备的结果，以评估术中运动。比较了智能手机辅助技术和使用机械对准引导的传统方法的杯位置超出 Lewinnek 安全区的情况。
2015 年 6 月至 2017 年 2 月，我们对 64 例接受后外侧入路初次非骨水泥全髋关节置换术（THA）的患者进行了随机对照试验。髋臼部件通过传统技术（ = 32）或使用智能手机技术（ = 32）植入。在仰卧骨盆射线照片中测量倾斜和前倾角。
智能手机组的倾斜角与常规组无显著差异（41.2°±3.9°对 40.3°±7.9°， = 0.567）。前倾角也相似（19.3±3.8°对 19.1°±5.9°，= 0.856）。然而，智能手机组的角度标准差在倾斜度（< 0.001）和前倾角（= 0.016）方面显著较低。智能手机组有 3 个离群值（9.4%），但常规组有 13 个（40.6%）（ = 0.008）。风险比为 0.23（95%CI，0.07-0.73）。风险差为-0.31（95%CI，-0.51- -0.11）。
THA 中的智能手机辅助技术提高了杯放置的精度，并降低了安全区离群值的百分比。泰国临床试验注册处（ID：TCTR20151123002）。
