单髁置换——手术创伤小，恢复快，在关节其他部分疾病进展后可以通过再次施行单间室手术治疗，并且在失败后转换成全膝关节置换术过程中手术难度远小于初次全膝关节置换术的翻修手术。因为上述优势，单髁置换与膝关节周围截骨被称为了保膝手术，是全膝关节置换术的有力替代治疗方案，可能给很大比例的患者带来更加微创的治疗手段。北京大学人民医院骨关节科李志昌

但对于外侧间室的病变，活动平台单髁置换手术不能像内侧间室那样给患者提供长期稳定的效果，其中重要原因是其脱位率要远高于内侧间室单髁手术。而由于外科大夫早已发现这一问题，并不断尝试各种方法进行改良，也取得了很大的进展。发表在关节置换杂志（JOA）的最新文章对英格兰、威尔士、北爱尔兰和马恩岛的国家关节登记系统中12年来所有的外侧间室单髁手术进行了回顾研究。结果发现，外侧间室单髁手术的10年假体生存率达到了88.6%，这和全膝置换手术的10年假体生存率已经十分接近。而其中55岁以下患者的失败率显著高于高龄患者，尤其是75岁以上患者的翻修率只有55岁以下患者的不到三分之一。肥胖患者的翻修率是BMI正常患者的2.33倍。最常见的翻修原因仍然是活动垫片的脱位，翻修率为2.3%占到了全部翻修原因的30%左右。

作者得出结论，对于单纯外侧间室骨关节炎，Oxford外侧间室蝶形单髁置换手术是一个很好的治疗选择。为了预防脱位，该假体设计可以在手术过程中评价脱位的风险，如果风险较大，则可以在不调整截骨的情况下直接更换为固定平台假体。

The mid to long term outcomes of the Lateral Domed Oxford Unicompartmental knee replacement: An analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

Abstract

Background

Lateral unicompartmental knee replacement (UKR) is an alternative to total knee replacement for isolated lateral unicompartmental knee arthritis. The geometry and mechanics of the lateral compartment differ to the medial compartment with the Lateral Domed Oxford UKR designed to address this. We used National Joint Registry (NJR) data to report the mid to long term outcomes of this device.

Methods

We performed a retrospective observational study using NJR data on 992 Lateral Domed Oxford UKRs implanted between 1 ^st January 2005 and 31 ^st December 2017. Outcomes of interest were implant survival and revision indications.

Results

The 10 year cumulative implant survival rates were 88.6% (CI 85.3-91.2). When compared to <55 year age group, the 55-64, 65-74 and ≥75 groups had significantly lower revision rates (Hazard Ratio (HR)=0.56 (CI 0.32-0.98, p=0.04), HR 0.40 (CI 0.22-0.72, p=0.003) and HR 0.27 (CI 0.12-0.58, p=0.001) respectively). The obese group had significantly (p=0.04) increased revision risk compared to normal BMI (HR 2.33, CI 1.06-5.12). The commonest reasons for revision surgery were dislocation (n=23, 2.3%), pain (n=15, 1.5%) and aseptic loosening (n=14, 1.4%).

Conclusion

The Lateral Domed Oxford UKR provides a good option for isolated lateral compartment osteoarthritis. However dislocation of the mobile bearing remains a problem, occurring in 2.3% of the patients and accounting for 30% of the revisions. To help prevent dislocation it is now possible to assess bearing stability intra-operatively and if very unstable to implant a compatible fixed bearing tibial component, without the need for further bone preparation.