Department of Orthopaedic Surgery, Asahikawa Medical University, Midorigaoka-Higashi 2-1-1-1, Asahikawa, 078-8510, Japan.
BMC Musculoskelet Disord. 2021 Mar 23;22(1):299. doi: 10.1186/s12891-021-04167-y.
Complications after total hip arthroplasty (THA) are frequently the consequence of malpositioned components or leg length discrepancy after surgery. Recently, a new version of a portable, accelerometer-based hip navigation system (New HipAlign) was made available with a change in the method of measuring cup abduction and the addition of a leg length measurement function. The purposes of this study were to investigate cup positioning and to examine the accuracy of leg length measurement with New HipAlign.
Cups were implanted and intraoperative leg length change was measured using New HipAlign in 60 THAs through a posterior approach in the lateral decubitus position. The cup position and radiographic leg length change were determined postoperatively on pelvic radiograph and computed tomography scans. We previously compared cup positioning with a previous version of a portable, accelerometer-based hip navigation system (Previous HipAlign) and conventional surgical techniques. Cup positioning in this study was compared with the results of out previous study using Previous HipAlign.
The mean cup abduction of 40.3° ± 4.9° (range, 26° to 53°) and the mean cup anteversion of 15.8° ± 5.6° (range, 6.7° to 29.5°) were found. The deviation of the postoperative measured angles from the target cup position was 3.7° ± 3.3° for cup abduction and 5.9° ± 3.6° for cup anteversion. 56/60 of the cups were inside the Lewinnek safe zone. Compared with our previous study using Previous HipAlign, there were no significant differences with regard to cup abduction, cup anteversion, the deviation from the target cup position for cup abduction, the value of deviation for cup anteversion, and the number of cups inside the Lewinnek safe zone (P = 0.218, 0.334, 0.651, 0.797, 0.592). The mean difference between the intraoperative and radiographic leg length changes was + 0.8 ± 3.4 mm. There was significant correlation between the intraoperative and radiographic leg length changes (r = 0.804, P = 0.000).
Use of New HipAlign allowed for accurate cup placement and reliable leg length measurement during THA.
Clinical trial is defined as 'any research study that prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcome' by the World Health Organization (WHO). Because this study is not a clinical trial, trial registration is not needed.
全髋关节置换术后（THA）的并发症通常是由于术后关节组件位置不当或下肢长度差异引起的。最近，一种新的便携式、基于加速度计的髋关节导航系统（New HipAlign）问世，该系统改变了测量杯外展的方法，并增加了下肢长度测量功能。本研究的目的是研究杯的位置，并检查 New HipAlign 测量下肢长度的准确性。
通过后路侧卧位对 60 例 THA 患者进行手术，使用 New HipAlign 植入髋臼杯并测量术中下肢长度的变化。术后在骨盆 X 线片和 CT 扫描上确定髋臼杯的位置和术后影像学下肢长度的变化。我们之前曾使用基于加速度计的便携式髋关节导航系统的前一版本（Previous HipAlign）和常规手术技术比较了髋臼杯的位置。本研究中的髋臼杯位置与我们之前使用 Previous HipAlign 的研究结果进行了比较。
发现髋臼杯外展平均为 40.3°±4.9°（范围为 26°至 53°），髋臼杯前倾角平均为 15.8°±5.6°（范围为 6.7°至 29.5°）。术后测量角度与目标髋臼杯位置的偏差为髋臼杯外展 3.7°±3.3°，髋臼杯前倾角 5.9°±3.6°。60 个髋臼杯中有 56 个位于 Lewinnek 安全区内。与我们之前使用 Previous HipAlign 的研究相比，髋臼杯外展、髋臼杯前倾角、髋臼杯外展目标位置的偏差、髋臼杯前倾角的偏差以及位于 Lewinnek 安全区内的髋臼杯数量均无显著差异（P=0.218、0.334、0.651、0.797、0.592）。术中与影像学下肢长度变化的平均差值为+0.8±3.4mm。术中与影像学下肢长度变化之间存在显著相关性（r=0.804，P=0.000）。
在 THA 中使用 New HipAlign 可以实现髋臼杯的准确放置和可靠的下肢长度测量。
无临床试验注册。
