[Baker's cysts. A follow-up study after surgical therapy].

Baker's cysts have to be regarded as a secondary phenomenon of knee-joint diseases. In the treatment of Baker's cysts, therefore, arthroscopy should be done before extirpation. In our study we wanted to look at the results of this therapeutic concept. In the surgical clinic within the Ruhr University of Bochum 34 patients with Baker's cysts underwent an operation between 1985 and 1992. In 22 patients the main symptom was swelling in the hollow of the knee, while the others reported effusions of the knee joint, pain or restricted joint movement. In 27 cases the diagnosis was made by ultrasound alone; in the others arthrography or NMR tomography was necessary. Arthroscopy was performed in all patients, revealing lesions of the meniscus in 12 cases, rupture of the cruciate ligament in 1, degenerative changes in 15 and chronic polyarthritis in 1. In 5 patients we could not find any pathologic changes. We observed 1 severe postoperative complication in the form of a joint infection. Histological examination of the cysts showed chronic synovialitis in 21 patients and tuberculous arthritis in 1. In 25 of our patients clinical and ultrasound examination were then performed on average of 34 months after their operations. In 4 patients we found recurrence of cysts: 2 of these patients were found to be suffering from chronic knee-joint disease with effusions; 1 had recurrent hydrarthrosis together with chronic renal insufficiency; and the fourth patient had constant knee pain, though the arthroscopy did not show any pathologic changes. In the last case our diagnosis was therefore called in question.(ABSTRACT TRUNCATED AT 250 WORDS)