The medial shelf of the knee. A follow-up study.

After a publication in 1979 on Plica Synovialis Mediopatellaris a review of 1328 arthroscopies from 1978 onwards has been done at the Orthopedic Department of the University Clinic Duesseldorf. One hundred and eighty knees with medial shelf of the knee were found. Forty-three patients were treated by arthroscopic surgery. Plica excision alone was carried out in 17 knees. Twenty-six times multiple intraarticular surgery like patella-shave, lateral release, meniscectomy or local synovectomy have been performed in addition to plica excision. A shelf alone was present in 21.1%. Additional lesion like chondromalacia of the patella occurred in 38.8%. Control of biopsy material and tissue specimen from arthroscopic surgery revealed shelf fibrosis in 15.5% of the 180 knees with Plica Synovialis Mediopatellaris. The best results were obtained in those patients with a medial shelf as the only abnormality in the knee joint. The reason for the relatively high amount of unsatisfactory results in knees with multiple lesion and medial shelf excision is caused by overlap of other lesions accompanied by the Plica Synovialis Mediopatellaris. Under the impression of the results of the follow-up study a detailed proposal as indication for Plica excision is discussed.