Coffey Simon P, Sorial Rami M, Sharma Rahul, Field John R
Department of Orthopaedics, Nepean Hospital, Penrith, New South Wales, Australia.
Department of Orthopaedics, Nepean Private Hospital, Penrith, New South Wales, Australia.
ANZ J Surg. 2021 Mar;91(3):398-403. doi: 10.1111/ans.16616. Epub 2021 Feb 1.
Radiostereometric analysis (RSA) is an established high precision tool enabling us to detect early implant migration in total hip arthroplasty. The aim of this study is to present the RSA and clinical results of a new cementless hip stem and to compare those with established benchmarks.
A total of 45 patients (46 hips) undergoing total hip arthroplasty were available for full radiographic and clinical assessment at 2 years post-operatively. Mean patient age was 69 (range 43-85) years and mean body mass index was 29 (range 21-38) kg/m . RSA was undertaken at day 1, 6 weeks, 6 months and 1 and 2 years post-operatively. Oxford hip score and EQ-5D-5L scores were recorded preoperatively and at the same other time points. Results were compared to published data of established implants.
At 2 years, mean subsidence and retroversion were 0.61 mm (standard deviation 0.7 mm, range -0.19 to 3.06 mm) and 0.44° (standard deviation 0.81°, range 0.98 to 3.29°), respectively. Stem migration occurred primarily in the first 6 weeks with no detectable subsidence or rotation at 6 months or 2 years. Mean Oxford hip score and EQ-5D-5L improved from 18.6 to 44.7, and 69 to 86, respectively. There was one cup-only revision and no revisions for stem loosening.
RSA serves as an accurate measure of femoral stem stability early in the post-operative period. Our data confirm that stability occurs as early as 6 weeks and is sustained at 2 years. The Paragon stem demonstrates stability parameters at 2 years that exceed other established benchmark implants.
放射性立体测量分析（RSA）是一种成熟的高精度工具，可使我们在全髋关节置换术中检测早期植入物移位。本研究的目的是介绍一种新型非骨水泥型髋关节柄的RSA及临床结果，并将其与既定基准进行比较。
共有45例（46髋）接受全髋关节置换术的患者在术后2年可进行全面的影像学和临床评估。患者平均年龄为69岁（范围43 - 85岁），平均体重指数为29（范围21 - 38）kg/m²。在术后第1天、6周、6个月以及1年和2年进行RSA。术前以及其他相同时间点记录牛津髋关节评分和EQ - 5D - 5L评分。将结果与已发表的既定植入物数据进行比较。
在2年时，平均下沉和后倾分别为0.61毫米（标准差0.7毫米，范围 - 0.19至3.06毫米）和0.44°（标准差0.81°，范围 - 0.98至3.29°）。柄的移位主要发生在最初6周，在6个月或2年时未检测到下沉或旋转。牛津髋关节评分和EQ - 5D - 5L评分分别从18.6提高到44.7和从69提高到86（满分100）。有1例仅进行了髋臼翻修，没有因柄松动而进行翻修。
RSA是术后早期股骨柄稳定性的准确测量方法。我们的数据证实稳定性早在6周时就已出现，并在2年时得以维持。Paragon柄在2年时显示出的稳定性参数超过其他既定的基准植入物。
