University of Toronto, Toronto, Ontario, Canada.
Arthritis Rheumatol. 2014 Feb;66(2):254-63. doi: 10.1002/art.38231.
Most of the evidence regarding complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA) are based on patients with osteoarthritis (OA); less is known about outcomes in rheumatoid arthritis (RA). Using a validated algorithm for identifying patients with RA, we undertook this study to compare the rates of complications among THA and TKA recipients between those with RA and those without RA.
In patients who underwent a first primary elective THA or TKA between 2002 and 2009, those with RA were identified using a validated algorithm: a hospitalization with a diagnosis code for RA or 3 physician billing claims with a diagnosis code for RA, with at least 1 claim by a specialist (rheumatologist, orthopedic surgeon, or internist) in a 2-year period. Recipients with diagnostic codes suggesting an inflammatory arthritis, but not meeting RA criteria, were classified as having inflammatory arthritis. All remaining patients were deemed to have OA. Cox proportional hazards models, censored on death, were used to determine the relationship between the type of arthritis and the occurrence of specific complications, adjusting for potential confounders (age, sex, comorbidity, and provider volume).
We identified 43,997 eligible THA recipients (3% with RA) and 71,793 eligible TKA recipients (4% with RA). Total joint arthroplasty recipients with RA had higher age and sex-standardized rates of dislocation following THA (2.45%, compared with 1.21% for recipients with OA) and higher age and sex-standardized rates of infection following TKA (1.26%, compared with 0.84% for recipients with OA). Controlling for potential confounders, recipients with RA remained at increased risk of dislocation within 2 years of THA (adjusted hazard ratio [HR] 1.91, P = 0.001) and remained at increased risk of infection within 2 years of TKA (adjusted HR 1.47, P = 0.03) relative to recipients with OA.
Patients with RA are at higher risk of dislocation following THA and are at higher risk of infection following TKA relative to those with OA. Further research is warranted to elucidate explanations for these findings, including the roles of medication profile, implant choice, postoperative antibiotic protocol, and method of rehabilitation following joint replacement.
大多数关于全髋关节置换术（THA）和全膝关节置换术（TKA）后并发症的证据都基于骨关节炎（OA）患者；关于类风湿关节炎（RA）患者的结果知之甚少。本研究采用一种经过验证的识别 RA 患者的算法，旨在比较 RA 和非 RA 的 THA 和 TKA 接受者之间并发症的发生率。
在 2002 年至 2009 年间接受首次原发性选择性 THA 或 TKA 的患者中，通过使用经过验证的算法识别出 RA 患者：有 RA 诊断代码的住院治疗或 3 次有 RA 诊断代码的医生计费索赔，其中至少有 1 次由专家（风湿病专家、骨科医生或内科医生）在 2 年内开具。有提示炎症性关节炎但不符合 RA 标准的诊断代码的患者被归类为患有炎症性关节炎。所有其余患者被认为患有 OA。使用 COX 比例风险模型，以死亡为删失变量，确定关节炎类型与特定并发症发生之间的关系，调整潜在混杂因素（年龄、性别、合并症和提供者数量）。
我们确定了 43997 名合格的 THA 接受者（3%患有 RA）和 71793 名合格的 TKA 接受者（4%患有 RA）。RA 全关节置换术接受者 THA 后脱位的年龄和性别标准化发生率更高（2.45%，而 OA 接受者为 1.21%），TKA 后感染的年龄和性别标准化发生率更高（1.26%，而 OA 接受者为 0.84%）。控制潜在混杂因素后，RA 患者在 THA 后 2 年内脱位的风险仍然增加（校正后的危险比[HR]1.91，P=0.001），在 TKA 后 2 年内感染的风险仍然增加（校正后的 HR 1.47，P=0.03）相对于 OA 患者。
与 OA 患者相比，RA 患者在 THA 后脱位的风险更高，在 TKA 后感染的风险更高。需要进一步研究阐明这些发现的原因，包括药物概况、植入物选择、术后抗生素方案以及关节置换术后康复方法的作用。
