Frimley Park NHS Foundation Trust, Camberley GU16 5UJ, UK.
Knee Surg Sports Traumatol Arthrosc. 2009 Oct;17(10):1178-83. doi: 10.1007/s00167-009-0779-z. Epub 2009 Mar 31.
Concerned by a perceived high revision rate, we retrospectively reviewed the survivorship of a series of 43 cemented, medial, mobile-bearing Preservation unicompartmental knee replacements implanted during a 2-year period at a single institution. The initial post-operative AP and lateral radiographs were independently assessed to test the hypothesis that suboptimal implantation of the prosthesis was responsible for early failure. An X-ray scoring system based on the criteria for assessing the Oxford mobile-bearing unicompartmental knee replacement was devised. The components of this score included assessment of prosthesis alignment, sizing and cementation. Nine (21%) LCS Preservation mobile-bearings prostheses had required revision at a mean of 22 months post-implantation. The commonest causes for failure were pain (44%) and tibial component loosening (33%). Analysis of post-operative radiographs showed no difference (n.s.) between the compound error scores for the revised and the surviving prostheses. No particular surgical error was identifiable leading to subsequent need for revision. The high failure rates shown in this study have led us to cease using this implant. The clinical relevance of this study is that the captive running track of the LCS mobile-bearing prosthesis may over constrain the meniscal component leading to early failure.
我们对一组 43 例在单中心接受固定型、内侧、活动型保膝单髁置换术患者的随访结果进行了回顾性研究，发现翻修率较高，因此感到担忧。我们假设假体植入位置不佳是导致早期失败的原因，对术后即刻的正侧位 X 线片进行了独立评估。我们设计了一种基于牛津活动型单髁膝关节置换术假体评估标准的 X 射线评分系统，该评分系统包括假体对线、尺寸和骨水泥固定情况的评估。9 例（21%）LCS 保膝活动型假体在植入后平均 22 个月需要翻修。最常见的失败原因是疼痛（44%）和胫骨组件松动（33%）。术后 X 线片分析显示，翻修组和存活组的复合误差评分无差异（无统计学意义）。没有发现导致后续翻修的特定手术错误。本研究中高失败率使我们停止使用这种植入物。本研究的临床意义在于，LCS 活动型假体的固定轨道可能会过度限制半月板组件，从而导致早期失败。
