Ultrasound Imaging Supplements the Plain Radiography in the Evaluation of the Knee Osteoarthritis / 대한류마티스학회지

ABSTRACT

OBJECTIVE: Ultrasonography (USG) of joints has a unique position for the diagnosis of joint diseases. Bone surface, cartilage, periarticular soft tissue and their pathologic changes can be assessed by USG. This study was aimed to compare the radiographic and ultrasonographic findings in osteoarthritis (OA) of the knee joint and to evaluate the usefulness of each modality to evaluate the disease early and determine the severity of the arthritis. METHODS: Fifty osteoarthritis patients classified by the American College of Rheumatology (ACR) clinical criteria from December 2002 to April 2003 were included in the study. Routine radiography (standing anteroposterior, lateral, skyline view) and systemic USG examination of both knee were performed. We compared the incidence of the radiographic and ultrasonographic abnormality related to the pathologic change of the knee OA and suggesting the severity of the OA which would help to decide the therapeutic modality. RESULTS: In patient with knee OA, plain radiography showed abnormal findings in 37/50 (74%) patients, but USG showed at least five abnormal findings in all 50 patients. The abnormal findings detected only by plain radiography were subchondral sclerosis and subchondral cyst (14% and 4% each). But, the thinning of cartilage (94%), Baker's cyst (94%), cartilage degeneration (54%), meniscal protrusion (44%), meniscal tear (34%), meniscal cyst (32%), and the pannus (22%) were detected only by USG. Among the findings shared by both method, joint space narrowing was detected better by plain radiography than USG, but fluid accumulation, spur, meniscal calcification and osteochondroma were detected more frequently by USG. CONCLUSION: USG is more sensitive to find the pathologic changes related to the knee OA and to diagnose OA than the plain radiography. But each of the plain radiography and USG have their own unique value for the evaluation of OA in the knee. So the USG supplements the plain radiography in the examination of the knee OA.