Aim: To assess and establish the reason for repeating knee arthroscopies. A retrospective study at Torbay General Hospital.

Methods and results: The sample period was from January-2004 to July 2007 during which 695 knee arthroscopies were done, of which 71 patients (10 %) were coded as having same knee scoped again. A total of 58 out of 71 patients notes were available for review of which 12 were excluded due to coding-error and septic-arthritis. Among the 45 patients included, 67% were males and mean age was 44 years (range 17 to 70 years). The average time from listing the patient to actual scope was 20 weeks (range 0 to 54). At their first scope 24 patients required partial meniscectomies, of which 11 (45%) and 6 (25%) patients had posterior-horn and body of medial meniscal tears respectively, and 7 (29%) had tears in posterior-horn of lateral meniscus. Among the 23 who had chondral defects, 73% had changes on medial femoral condyle, 70% on patella, 52% on medial tibial condyle, 47% over lateral femoral condyle, 43% on trochlear grove, and 39% on lateral tibial condyle. Thirty-three-percent patients had anterior cruciate ligament (ACL) tears and 6% require loose bodies removal.

Average time between re-scopes was 16 months (range 0 to 3.5 years). The numbers of patients requiring repeat knee arthroscopy for similar clinical problems were 16 out of 695 patients (2.3%). During repeat arthroscopies, 10/16 (62%) required procedures on meniscus, 4/16 (25%) for osteochondral lesions 2 patients had same diagnosis as ACL tears. 90% of partial meniscectomies were repeated on the posterior horn of both medial and lateral meniscus, and 20% required trimming of body of the meniscus.

Conclusion: Contrary to general opinion being too many patients knees are been re-scoped, only 16/695 patients (2.3%) had their knees re-scoped for similar problem as found at first arthroscopy. 62% of these patients required partial meniscectomy mainly on the posterior-horns and 25% had chondral defects. We concluded that MR-arthrogram should be considered due to its specificity and sensitivity as detailed in literature, before performing repeated knee arthroscopy.