Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Nuffield Orthopaedic Centre, University of Oxford, Oxford, United Kingdom.
Barts Bone & Joint Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.
J Bone Joint Surg Am. 2024 Sep 4;106(17):1553-1562. doi: 10.2106/JBJS.23.01418. Epub 2024 Jul 9.
Unicompartmental knee replacement (UKR) is an effective treatment for end-stage medial compartment osteoarthritis, but there can be problems with fixation. The cementless UKR was introduced to address this issue. It is unknown how its functional outcomes compare with those of the cemented version on a national scale. We performed a matched comparison of the clinical and functional outcomes of cementless and cemented UKRs.
Using the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR), 14,764 Oxford UKRs with linked data regarding patient-reported outcomes were identified. A total of 6,906 UKRs (3,453 cemented and 3,453 cementless) were propensity score matched on the basis of patient, surgical, and implant factors.
The 10-year cumulative implant survival rate was 93.0% (95% confidence interval [CI], 90.0% to 95.1%) for cementless UKRs and 91.3% (95% CI, 89.0% to 93.0%) for cemented UKRs. The cementless UKR group had a significantly lower revision risk (hazard ratio [HR], 0.74; p = 0.02). Subgroup analyses showed a stronger effect size (HR, 0.66) among UKRs performed by high-caseload surgeons (i.e., surgeons performing ≥30 UKRs/year). In the overall cohort, the postoperative Oxford Knee Score (OKS) in the cementless group (mean and standard deviation, 39.1 ± 8.7) was significantly higher (p = 0.001) than that in the cemented group (38.5 ± 8.6). The cementless group gained a mean of 17.6 ± 9.3 points in the OKS postoperatively and the cemented group gained 16.5 ± 9.6 points, with a difference of 1.1 points between the groups (p < 0.001). The difference in OKS points gained postoperatively was highest among UKRs performed by high-caseload surgeons, with the cementless group gaining 1.8 points more (p < 0.001) than the cemented group.
The cementless UKR demonstrated better 10-year implant survival and postoperative functional outcomes than the cemented UKR. The difference was largest among UKRs performed by high-caseload surgeons, with the cementless fixation group having an HR for revision of 0.66 and an approximately 2-point greater improvement in the OKS compared with the cemented fixation group.
Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.
单髁膝关节置换术（UKR）是治疗终末期内侧间室骨关节炎的有效方法，但存在固定问题。为了解决这个问题，引入了非骨水泥 UKR。目前尚不清楚其在全国范围内的功能结果与骨水泥版本相比如何。我们对非骨水泥和骨水泥 UKR 的临床和功能结果进行了匹配比较。
利用英格兰、威尔士、北爱尔兰和马恩岛国家联合登记处（NJR），确定了 14764 例牛津 UKR，并对患者报告的结果进行了数据链接。根据患者、手术和植入物因素，对总共 6906 例 UKR（骨水泥 3453 例，非骨水泥 3453 例）进行了倾向评分匹配。
非骨水泥 UKR 的 10 年累积植入物生存率为 93.0%（95%置信区间[CI]，90.0%至 95.1%），骨水泥 UKR 为 91.3%（95%CI，89.0%至 93.0%）。非骨水泥 UKR 组的翻修风险显著降低（风险比[HR]，0.74；p=0.02）。亚组分析显示，在高病例量外科医生（即每年行≥30 例 UKR 的外科医生）中，效应大小更强（HR，0.66）。在总体队列中，非骨水泥组的术后牛津膝关节评分（OKS）（平均值和标准差，39.1±8.7）显著更高（p=0.001），骨水泥组为 38.5±8.6。非骨水泥组术后 OKS 平均增加 17.6±9.3 分，骨水泥组增加 16.5±9.6 分，两组之间相差 1.1 分（p<0.001）。高病例量外科医生行 UKR 术后 OKS 增加幅度最大，非骨水泥组比骨水泥组多增加 1.8 分（p<0.001）。
非骨水泥 UKR 与骨水泥 UKR 相比，10 年植入物生存率和术后功能结果更好。在高病例量外科医生行 UKR 中差异最大，非骨水泥固定组的翻修风险 HR 为 0.66，与骨水泥固定组相比，OKS 平均改善约 2 分。
预后 III 级。有关证据水平的完整描述，请参见作者说明。
