[Arthrography and ultrasound scanning for the detection of Baker cysts (author's transl)].

23 knee joints with clinical evidence of Baker's cysts have been studied in comparison by arthrography and ultrasound-scanning. In 20 knees, there was correlation between arthrographic and sonographic findings. In 3 cases, a positive sonogram was not confirmed by arthrography. Possible causes for faulty interpretation and differential diagnoses have been discussed. We prefer ultrasound scanning for the diagnosis in inflammatory and degenerative joint diseases because it is entirely harmless. In cases of traumatic Baker cysts the arthrogram may reveal an additional meniscal injury.