类风湿关节炎膝股骨髁软骨厚度与临床特征的相关性

Correlation between knee femur condylar cartilage thickness and clinical features of rheumatoid arthritis

目的通过超声观察类风湿关节炎(rheumatoid arthritis,RA)患者膝关节病变特点,探讨膝股骨髁软骨(femoral condylar cartilage,FCC)厚度与RA临床特征的相关性。方法应用超声探查70例RA、50例膝骨性关节炎(knee osteoarthritis,KOA)和30例健康对照者(healthy controls,HC)的双膝关节,测量FCC外侧、中间、内侧厚度。收集入组者体重指数(body mass index,BMI)、红细胞沉降率(erythrocyte sedimentation rate,ESR)、C反应蛋白(C-reaction protein,CRP)、类风湿因子(rheumatoid factors,RF)、抗环瓜氨酸肽抗体(anti-cyclic citrullinated peptide antibody,抗CCP抗体)和基于CRP的28个关节疾病活动度评分,比较各组实验室指标和超声指标的差异,FCC厚度与疾病特点的相关性分析采用Pearson相关系数检验。结果①KOA组BMI高于RA组和HC组(P<0.05);RA组和KOA组FCC厚度均低于HC组(P<0.05),RA组和KOA组FCC厚度差异无统计学意义(P>0.05)。②RA组膝关节超声病变形式较KOA组多样化,RA组软骨病变、关节积液、骨赘阳性率低于KOA组(P<0.05);2组滑膜增生、腘窝囊肿阳性率差异无统计学意义(P>0.05)。RA组还表现为滑膜内血流、骨侵蚀、游离体、附着点炎、腱周炎。③RA膝关节肿痛组年龄、BMI、ESR、CRP、抗CCP抗体、疾病活动度评分均高于膝关节无肿痛组(P<0.01),2组FCC厚度差异无统计学意义(P>0.05);RA组(≤50岁)FCC外侧厚度低于HC组(≤50岁)(P<0.05);RA病程≥5年组FCC外侧厚度低于病程≤2年组(P<0.05)。④FCC外侧厚度与RA病程呈负相关(r=-0.301,P=0.019)。结论RA膝关节病变超声多样表现有助于RA和KOA的鉴别诊断。无论RA患者临床是否有膝关节症状,FCC可能已发生损伤;50岁以下RA患者早发FCC外侧厚度变薄;患病时间5年以上的RA患者FCC外侧厚度更薄。

Objective To observe the ultrasonic features of knee lesions in rheumatoid arthritis(RA)patients and to explore the relationship between the thickness of femoral condylar cartilage(FCC)and clinical features of RA.Methods The lateral,middle and medial thickness of FCC was measured by ultrasound in 70 patients with RA,50 patients with knee osteoarthritis patients(KOA)and 30 healthy controls(HC).Body mass index(BMI),erythrocyte sedimentation rate(ESR),C-reaction protein(CRP),rheumatoid factors(RF),anti-cyclic citrullinated peptide antibody(anti-CCP antibody),and 28-joint disease activity score(DAS28)were recorded,and the differences in laboratory and ultrasonic indexes in each group were compared.The correlation between FCC thickness and clinical features was analyzed by Pearson correlation coefficient test.Results①The BMI of KOA group was higher than that of RA group and HC group(P<0.05).The thickness of FCC in RA group and KOA group was thinner than that in HC group(all P<0.05).There was no significant difference in thickness of FCC between RA group and KOA group(P>0.05).②The ultrasonic lesions of knee joint in RA group were more diverse than those in KOA group.The positive rates of cartilage lesions,joint effusion and osteophytes in RA group were lower than those in KOA group(all P<0.05).There was no significant difference in the positive rate of synovial hyperplasia and Baker′s cyst between two groups(P>0.05).In addition,the RA group had blood flow signal in synovial membrane,bone erosion,loose body,enthesitis and peritendinitis.③Age,BMI,ESR,CRP,anti-CCP antibody and DAS28 in RA knee swollen/tender group were higher than that in RA knee without swollen/tender group(all P<0.01),and there was no significant difference in thickness of FCC between two groups(P>0.05).The lateral thickness of FCC in RA group(≤50 years of age)was thinner than that in HC group(≤50 years of age)(P<0.05).The lateral thickness of FCC in RA≥5 years group was thinner than that in RA≤2 years group(P<0.05).④FCC lateral thickness was negatively correlated with RA duration(r=-0.301,P=0.019).Conclusion Multiple ultrasound presentations of RA knee lesions may be helpful in the differential diagnosis of RA and KOA.FCC injury may occur in RA patients regardless of whether they have clinical symptoms in the knee.RA patients younger than 50 years of age have a thinning of the FCC lateral thickness.The FCC lateral thickness is thinner in RA patients with more than 5 years of duration.