PDF(Pubmed)
Abstract：
BACKGROUND: Modular acetabular components for total hip arthroplasty (THA) provide intraoperative flexibility; however, polyethylene liner dissociation may occur. This study aimed to examine the incidence and causes of liner dissociation associated with a specific acetabular component design at a single centre.
METHODS: A retrospective analysis of 7027 patients who underwent primary THA was performed to identify isolated liner dislocations. Patient demographics, clinical presentations, surgical and implant details, and both radiographic and computed tomography (CT) findings were analysed. Patients with liner dislocation were matched to a control group via 2:1 propensity score matching, and a logistic regression analysis was employed to identify associated risk factors.
RESULTS: A total of 32 patients (0.45%) experienced liner dislocation at a mean 71.47 ± 60.10 months post surgery. Significant factors contributing to dislocations included the use of a conventional compared with a highly crosslinked polyethylene component (p = 0.049) and screw fixation (p = 0.028). Radiographic and CT analysis highlighted the importance of proper component orientation, revealing that patients experiencing dislocations demonstrated significantly lower acetabular cup anteversion angles (p = 0.001) compared with the control group. Impingement and malposition, identified in 41% and 47% of the cases, respectively, further underscored the multifactorial nature of dislocation risks.
CONCLUSIONS: While the overall rate of polyethylene liner dislocation was low, the findings of this study highlight the importance of appropriate cup placement to decrease the risk of dissociation. It further substantiates the influence of impingement and malposition in liner displacement, with increased mechanical stress exerted on the locking mechanism under adverse conditions and the potential risk increase due to screw placement.
METHODS: A retrospective analysis of 7027 patients who underwent primary THA was performed to identify isolated liner dislocations. Patient demographics, clinical presentations, surgical and implant details, and both radiographic and computed tomography (CT) findings were analysed. Patients with liner dislocation were matched to a control group via 2:1 propensity score matching, and a logistic regression analysis was employed to identify associated risk factors.
RESULTS: A total of 32 patients (0.45%) experienced liner dislocation at a mean 71.47 ± 60.10 months post surgery. Significant factors contributing to dislocations included the use of a conventional compared with a highly crosslinked polyethylene component (p = 0.049) and screw fixation (p = 0.028). Radiographic and CT analysis highlighted the importance of proper component orientation, revealing that patients experiencing dislocations demonstrated significantly lower acetabular cup anteversion angles (p = 0.001) compared with the control group. Impingement and malposition, identified in 41% and 47% of the cases, respectively, further underscored the multifactorial nature of dislocation risks.
CONCLUSIONS: While the overall rate of polyethylene liner dislocation was low, the findings of this study highlight the importance of appropriate cup placement to decrease the risk of dissociation. It further substantiates the influence of impingement and malposition in liner displacement, with increased mechanical stress exerted on the locking mechanism under adverse conditions and the potential risk increase due to screw placement.
摘要：
背景：用于全髋关节置换术（THA）的模块化髋臼组件提供了术中灵活性；然而，聚乙烯衬里可能发生解离。这项研究旨在检查与单个中心的特定髋臼组件设计相关的衬里解离的发生率和原因。
方法：对7027例原发性THA患者进行回顾性分析，以确定孤立的衬里脱位。患者人口统计学，临床表现,手术和植入细节，并分析了影像学和计算机断层扫描（CT）的发现。衬垫脱位患者通过2:1倾向评分匹配与对照组匹配，并采用logistic回归分析确定相关危险因素.
结果：共有32例患者（0.45%）在术后平均71.47±60.10个月出现衬垫脱位。导致位错的重要因素包括与高度交联的聚乙烯组分（p=0.049）和螺钉固定（p=0.028）相比，使用了常规的位错。射线照相和CT分析强调了正确定位组件的重要性，与对照组相比，发生脱位的患者显示出明显较低的髋臼杯前倾角（p=0.001）。撞击和错位，在41%和47%的病例中发现，分别,进一步强调了脱位风险的多因素性质。
结论：虽然聚乙烯衬垫的整体脱位率很低，这项研究的结果强调了适当放置杯子对降低解离风险的重要性.它进一步证实了冲击和错位对衬垫位移的影响，在不利条件下施加在锁定机构上的机械应力增加，并且由于螺钉放置而导致的潜在风险增加。
方法：对7027例原发性THA患者进行回顾性分析，以确定孤立的衬里脱位。患者人口统计学，临床表现,手术和植入细节，并分析了影像学和计算机断层扫描（CT）的发现。衬垫脱位患者通过2:1倾向评分匹配与对照组匹配，并采用logistic回归分析确定相关危险因素.
结果：共有32例患者（0.45%）在术后平均71.47±60.10个月出现衬垫脱位。导致位错的重要因素包括与高度交联的聚乙烯组分（p=0.049）和螺钉固定（p=0.028）相比，使用了常规的位错。射线照相和CT分析强调了正确定位组件的重要性，与对照组相比，发生脱位的患者显示出明显较低的髋臼杯前倾角（p=0.001）。撞击和错位，在41%和47%的病例中发现，分别,进一步强调了脱位风险的多因素性质。
结论：虽然聚乙烯衬垫的整体脱位率很低，这项研究的结果强调了适当放置杯子对降低解离风险的重要性.它进一步证实了冲击和错位对衬垫位移的影响，在不利条件下施加在锁定机构上的机械应力增加，并且由于螺钉放置而导致的潜在风险增加。
