Howie Donald W, Holubowycz Oksana T, Callary Stuart A
Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Adelaide, SA, Australia.
J Bone Joint Surg Am. 2016 Nov 2;98(21):1786-1793. doi: 10.2106/JBJS.15.01248.
Larger articulations reduce the risk of dislocation following primary total hip arthroplasty, leading to increased use of these articulations. The wear rate of highly cross-linked polyethylene (XLPE) is low in standard-diameter articulations but remains unclear in larger articulations. The aim of this randomized controlled trial was to compare the mean wear rates of 36-mm and 28-mm metal-on-XLPE articulations between 1 and 3 years postoperatively.
Fifty-six elderly patients undergoing primary total hip arthroplasty were randomized intraoperatively to receive either a 36-mm or 28-mm metal-on-XLPE articulation. Factors that may affect wear were controlled by study design. Wear was measured using radiostereometric analysis.
Mean annual proximal wear rates between 1 and 3 years were 0.00 and 0.01 mm/yr for the 36 and 28-mm articulation cohorts, respectively. No patient had a proximal wear rate of >0.1 mm/yr. Mean wear was very low in all directions, and the wear rate of 36-mm articulations was not significantly greater than that of 28-mm articulations on the basis of proximal, medial 2-dimensional, and 3-dimensional wear.
The wear rate of a larger 36-mm metal-on-XLPE articulation between 1 and 3 years following primary total hip arthroplasty was low and no greater than that of a 28-mm articulation. However, before a 36-mm metal-on-XLPE articulation is widely recommended, particularly in young active patients, long-term wear rates and association between wear and periprosthetic osteolysis should be determined.
Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
更大尺寸的关节在初次全髋关节置换术后可降低脱位风险，这使得此类关节的使用增多。在标准直径的关节中，高交联聚乙烯（XLPE）的磨损率较低，但在更大尺寸的关节中情况仍不明确。本随机对照试验的目的是比较术后1至3年36毫米和28毫米金属对XLPE关节的平均磨损率。
56例接受初次全髋关节置换术的老年患者在术中随机接受36毫米或28毫米金属对XLPE关节。可能影响磨损的因素通过研究设计加以控制。采用放射立体分析测量磨损情况。
1至3年期间，36毫米和28毫米关节组的年近端平均磨损率分别为0.00和0.01毫米/年。没有患者的近端磨损率>0.1毫米/年。各个方向的平均磨损都非常低，基于近端、内侧二维和三维磨损情况，36毫米关节的磨损率并不显著高于28毫米关节。
初次全髋关节置换术后1至3年，更大尺寸的36毫米金属对XLPE关节的磨损率较低，且不高于28毫米关节。然而，在广泛推荐使用36毫米金属对XLPE关节之前，尤其是在年轻活跃患者中，应确定其长期磨损率以及磨损与假体周围骨溶解之间的关联。
治疗性二级。有关证据水平的完整描述，请参阅作者须知。
