Resection of painful shelf (plica synovialis mediopatellaris) under arthroscopy.

In a series of 3,250 patients with knee disorders, a painful shelf was diagnosed and resected in 39 knees of 32 patients. Thirty of them were done by arthroscopy and nine by arthrotomy. There were 10 men and 22 women whose ages ranged from 4 to 55 years, with an average of 19 years. The follow-up period ranged from 1 to 6 years. Postoperatively, the pain was relieved in 26 knees and diminished in 13. A cord-like mass, palpable in 30 knees, disappeared in 25 postoperatively. Clicks were noted in 34 knees; 28 of these were not audible or palpable postoperatively. The provocation test 1 result was positive in 23 of 28 knees preoperatively, negative in 21, and diminished in 2 postoperatively. The provocation test 2 was performed in 23 knees; it produced pain and/or palpable click in 14 preoperatively, and was negative in 12 and diminished in 2 postoperatively.