Correlation between Sonographic Severity and Biochemical Markers of Synovium and Cartilage in Knee Osteoarthritis Patients

Jung, Young Ok; Kim, Hae Rim; Kang, Hyo Jong; Yoo, Seung Ah; Nah, Jong Myoung; Cho, Chul Soo; Kim, Ho Youn; Kim, Wan Uk

Abstract

OBJECTIVE
Ultrasonography has benefit in detecting soft tissue abnormalities within the joints, which cannot be assessed by conventional X-ray. In this study, we investigated the relationship between soft tissue and/or bony abnormalities on ultrasonography and biochemical markers of synovium and cartilage in knee osteoarthritis (OA) patients
METHODS
Fifty-one knee OA patients who fulfilled the ACR criteria were enrolled in this study. Knee ultrasonography was performed in affected knee joints with a 12 MHz linear probe to assess the presence of effusion, synovial proliferation, capsular distension, length of osteophytes, and thickness of cartilage. At the same time, the serum levels of hyaluronic acid (HA) and cartilage oligomeric protein (COMP) were measured by ELISA and serum osteocalcin levels were determined by RIA.
RESULTS
The patients with longer medial osteophytes showed higher levels of serum HA and COMP than those with shorter ones. Serum HA levels were significantly higher in patients with larger amount of effusion and/or synovial proliferation, suggesting inflammatory changes within the joint, than those without. In addition, the severity of capsular distention was also correlated well with serum HA and COMP levels. However, the length of lateral osteophytes and thickness of femoral cartilage were not correlated with serum HA or COMP levels. Serum osteocalcin levels did not show any association with above ultrasonographic parameters, either.
CONCLUSIONS
Using knee ultrasonography, we demonstrated that serum HA and COMP levels were elevated in more severe OA patients than less severe patients. This result suggests that detailed pathologic changes in the soft tissue and/or bone of OA joints on ultrasonography are being directly reflected to biochemical markers measured in the peripheral blood.