Dysplasia_Clinical.xlsx

<b>Abstract</b> <i>Background:</i> Arthritis secondary to developmental hip dysplasia often mandates implant surgery at a relatively young age. Hip resurfacing arthroplasty (HRA), compared with standard stemmed total hip arthroplasty (THA), affords a more active lifestyle including extreme-motion activities but stimulates concerns pertaining to implant failure. <i>Methods:</i><b> </b>We addressed the primary modes of failure through a series of interventions, including a new guideline for achieving proper implant alignment through intraoperative x-rays. We then compared two sequential cohorts in a single-surgeon practice: patients with developmental dysplasia who underwent HRA before (Group 1; 121 hips in 105 patients) and after (Group 2; 242 hips in 210 patients) June 2008, at which time the four interventions were all in place. <i>Results: </i>Implants in Group 2 failed less frequently within two years (0.8% vs. 6.6%, p = 0.002) and were more likely to have projected seven-year Kaplan-Meier survivorship (99% vs. 89%, p &lt; 0.0001 by log-rank test). Patients in Group 2 were more likely to have normal metal ion levels (77% vs. 56%, p = 0.0008) and optimum metal ion levels (99% vs. 86%, p = 0.0008). Patients in Group 2 also benefited from a 19-minute decrease in mean operation time, a 45% decrease in mean estimated blood loss, and a 0.9-day decrease in mean hospital stay (p &lt; 0.0001 in each instance). <i>Conclusions: </i>We believe the interventions reported here, combined with sufficient surgeon experience and properly designed implants, afford patients with developmental dysplasia a more active lifestyle with favorable implant survival.

<b>摘要</b> <i>背景：</i>继发于发育性髋关节发育不良（developmental hip dysplasia）的关节炎往往需要在相对年轻的年龄段接受植入手术。与标准柄型全髋关节置换术（standard stemmed total hip arthroplasty, THA）相比，髋关节表面置换术（hip resurfacing arthroplasty, HRA）可使患者拥有更为活跃的生活方式，包括参与极端运动活动，但也引发了人们对植入物失效的担忧。<i>方法：</i>本研究通过一系列干预措施探究植入物失效的主要模式，其中包括一项依托术中X线检查实现植入物精准对位的全新指南。随后，在同一位外科医生的临床实践中，我们比较了两个连续队列的患者：2008年6月之前接受HRA的发育性髋关节发育不良患者（第1组：105例患者共121髋），以及2008年6月之后接受HRA的患者（第2组：210例患者共242髋），此时四项干预措施均已全面实施。<i>结果：</i>第2组植入物的2年内失效发生率更低（0.8% vs. 6.6%，p=0.002），其预估7年Kaplan-Meier生存率更高（99% vs. 89%，经对数秩检验（log-rank test），p<0.0001）。第2组患者的金属离子水平更易维持正常（77% vs. 56%，p=0.0008），且达到最优金属离子水平的比例更高（99% vs. 86%，p=0.0008）。此外，第2组患者的平均手术时间缩短19分钟，平均预估失血量减少45%，平均住院时长缩短0.9天（各项指标p均<0.0001）。<i>结论：</i>我们认为，本文所述的干预措施结合充足的外科医师经验与经过合理设计的植入物，可使发育性髋关节发育不良患者拥有更为活跃的生活方式，同时获得良好的植入物生存率。