[Baker's cysts in patients with gonarthrosis in early stages according to arthrosonography and magnetic resonance tomography].

We studied potentialities of MR-tomography (MRT) and arthrosonography (ASG) for diagnosis of Baker's cysts in patients with early gonarthrosis (GA) regarding X-ray stage and presence of reactive synovitis. A total of 50 GA patients were examined. 100 knee joints were examined by x-ray and ASG, 79 ones by MRT (ALOKA-2200 ultrasound unit, 7.5 MHz sensor; 1.5 T Eclipse tomography, 1.5 T, Marconi, Picker). The ultrasound sensor was applied to the anterior and posterior surface of the knee joints in maximally extended joint in a dorsal position. MRT was made in a partially flexed fixed joint. It was found that the percentage of Baker's cyst (BC) diagnosis by MRT and ASG varies insignificantly (35.4 and 30.4%, respectively). Combined use of MRT and ASG detected the cysts more frequently in GA stage II by Kellgren (60.7% by MRT and 62.5% by ASG, p > 0.05). Combination of subclinical synovitis and the cysts was detected by MRT and sonography in 66.6 and 60% of the joints. Both MRT and ASG revealed no correlations between the frequency of BC and clinical synovitis. Both methods more frequently detected popliteal cysts and BC in subclinical synovitis.