INTERNAL DERANGEMENTS OF THE KNEE - RATES OF OCCURRENCE AT MR-IMAGINGIN PATIENTS REFERRED BY ORTHOPEDIC SURGEONS COMPARED WITH RATES IN PATIENTS REFERRED BY PHYSICIANS WHO ARE NOT ORTHOPEDIC SURGEON

PURPOSE: To compare the occurrence at magnetic resonance (MR) imaging of clinically important knee abnormalities in patients referred by ort hopedic surgeons with that in patients referred by other physicians. M ATERIALS AND METHODS: Knee MR images in all patients referred for eval uation of internal derangement for 12 months were retrospectively revi ewed. Meniscus, ligament, and articular cartilage abnormalities were t abulated. The numbers of abnormalities detected in the patients referr ed by orthopedic surgeons were compared with those in the patients ref erred by all other physicians by using chi(2) analysis. Significance w as defined at P less than .05. RESULTS: Knee MR images in 439 patients were reviewed; 328 patients were referred by orthopedic surgeons, and 111 were referred by other physicians. There was no significant diffe rence in the rates of occurrence of meniscus tear (149 [45%; orthopedi c surgeon referrals] vs 50 [45%; other physician referrals], P = .96); ligament tear (82 [25%] vs 21 [19%], P = .25); isolated hyaline carti lage defect (77 [23%] vs 20[18%], P = 29); meniscus or ligament tear ( 167[51%] vs 55[50%]; P = .86); or meniscus, ligament, or articular car tilage tear (242[74%] vs [65%], P = .34). The proportion of patients w ho subsequently underwent surgery of the knee was also similar (39%[11 8 of 300] vs 28%[23 of 82], P = .14). CONCLUSION: There was no signifi cant difference in the occurrences of clinically important knee intern al derangement at MR imaging between patients referred by orthopedic s urgeons and those referred by other physicians.