Knee arthrography for the preoperative evaluation of juxta-articular masses.

Knee arthrography was performed on twenty-one patients with osseous and extraosseous masses about the knee. Twelve patients had arthrographic abnormalities. Joint involvement was accurately delineated in nine of the ten cases where it was present. Three other patients had small suprapatellar bursae with superior flattening, characteristic of noncommunicating suprapatellar synovial cysts. Fluoroscopic spot radiographs and conventional radiographs after injection of contrast material adequately defined the synovial recesses. Tomograms were needed whenever articular cartilage invasion was a possibility. The arthrographic findings were useful in planning the operative approach in all cases except for the one case where the arthrogram did not detect the intra-articular invasion.