Malhotra Rajesh, Gaba Sahil, Wahal Naman, Kumar Vijay, Srivastava Deep N, Pandit Hemant
Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India.
Department of Radiodiagnosis, All India Institute of Medical Sciences, New Delhi, India.
J Knee Surg. 2019 Mar;32(3):205-210. doi: 10.1055/s-0038-1635113. Epub 2018 Feb 28.
Oxford unicompartmental knee replacement (OUKR) has shown excellent long-term clinical outcomes as well as implant survival when used for correct indications with optimal surgical technique. Anteromedial osteoarthritis is highly prevalent in Indian patients, and OUKR is the ideal treatment option in such cases. Uncertainty prevails about the best method to determine femoral component size in OUKR. Preoperative templating has been shown to be inaccurate, while height- and gender-based guidelines based on European population might not apply to the Indian patients. Microplasty instrumentation introduced in 2012 introduced the sizing spoon, which has the dual function of femoral component sizing and determining the level of tibia cut. We aimed to check the accuracy of sizing spoon and also to determine whether the present guidelines are appropriate for use in the Indian patients. A total of 130 consecutive Oxford mobile bearing medial cemented UKR performed using the Microplasty instrumentation were included. The ideal femoral component size for each knee was recorded by looking for overhang and underhang in post-operative lateral knee radiograph. The accuracy of previous guidelines was determined by applying them to our study population. Previously published guidelines (which were based on Western population) proved to be accurate in only 37% of cases. Hence, based on the demographics of our study population, we formulated modified height- and gender-based guidelines, which would better suit the Indian population. Accuracy of modified guidelines was estimated to be 74%. The overall accuracy of sizing spoon (75%), when used as an intraoperative guide, was similar to that of modified guidelines. Existing guidelines for femoral component sizing do not work in Indian patients. Modified guidelines and use of intraoperative spoon should be used to choose the optimal implant size while performing OUKR in Indian patients.
牛津单髁膝关节置换术（OUKR）在采用最佳手术技术用于正确适应证时，已显示出优异的长期临床疗效以及假体生存率。前内侧骨关节炎在印度患者中极为普遍，在这种情况下OUKR是理想的治疗选择。关于OUKR中确定股骨组件尺寸的最佳方法尚无定论。术前模板测量已被证明不准确，而基于欧洲人群的身高和性别指南可能不适用于印度患者。2012年引入的微型塑形器械配备了尺寸测量匙，其具有确定股骨组件尺寸和胫骨截骨水平的双重功能。我们旨在检验尺寸测量匙的准确性，并确定当前指南是否适用于印度患者。共纳入了130例连续使用微型塑形器械进行的牛津活动平台内侧骨水泥固定UKR手术。通过观察术后膝关节侧位X线片上的悬垂和不足来记录每个膝关节的理想股骨组件尺寸。通过将先前的指南应用于我们的研究人群来确定其准确性。先前发表的指南（基于西方人群）仅在37%的病例中被证明是准确的。因此，基于我们研究人群的人口统计学特征，我们制定了经修改的基于身高和性别的指南，该指南更适合印度人群。经修改指南的准确性估计为74%。尺寸测量匙作为术中引导工具时的总体准确性（75%）与经修改指南的准确性相似。现有的股骨组件尺寸测量指南不适用于印度患者。在为印度患者进行OUKR手术时，应使用经修改的指南和术中尺寸测量匙来选择最佳的植入物尺寸。
