Nishio Shoji, Fukunishi Shigeo, Fukui Tomokazu, Fujihara Yuki, Yoshiya Shinichi
Department of Orthopedic Surgery, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
J Orthop Sci. 2011 Mar;16(2):171-6. doi: 10.1007/s00776-011-0038-2. Epub 2011 Mar 11.
Adjustment of leg length discrepancy is an important factor influencing the outcome of total hip arthroplasty (THA). However, leg length discrepancy after THA has been reported to be associated with inferior clinical outcome in previous studies. A new version of the imageless navigation software "OrthoPilot THAplus" has been developed to assess the leg length adjustment and offset value. The clear advantage of this system is the elimination of the need for femoral pin insertion, which is associated with potential complications and additional surgical invasion.
In this study, the accuracy of this newly developed system was evaluated in 50 consecutive hips implanted with primary THA. The operative results of these 50 patients were compared with those of another 50 consecutive primary THA patients operated on with the previous navigation system that was not equipped with the leg length adjustment system.
After surgery, the average leg length discrepancy in the THA plus group was 0.9 mm (range -5 to 5 mm), while the corresponding value in the other group with the older software was 2.9 mm (range -13 to 20 mm), showing a significant difference.
The accuracy and reproducibility of new software added to the imageless THA navigation system in achieving equalization of leg length were assessed. Comparison of the surgical results as compared with the control group performed with the conventional navigation system showed the advantage of this system over the previous system.
肢体长度差异的调整是影响全髋关节置换术（THA）结果的重要因素。然而，先前的研究报道THA术后肢体长度差异与较差的临床结果相关。已开发出一种新版本的无图像导航软件“OrthoPilot THAplus”来评估肢体长度调整和偏移值。该系统的明显优势在于无需插入股骨钉，而这与潜在并发症及额外的手术创伤相关。
在本研究中，对连续50例接受初次THA的髋关节使用这种新开发的系统进行准确性评估。将这50例患者的手术结果与另外50例连续接受初次THA且使用未配备肢体长度调整系统的旧导航系统进行手术的患者的结果进行比较。
术后，THAplus组的平均肢体长度差异为0.9毫米（范围为-5至5毫米），而使用旧软件的另一组相应值为2.9毫米（范围为-13至20毫米），显示出显著差异。
评估了添加到无图像THA导航系统中的新软件在实现肢体长度均衡方面的准确性和可重复性。与使用传统导航系统的对照组相比，手术结果的比较显示了该系统相对于先前系统的优势。
