Comparison of knee magnetic resonance imaging findings in patients referred by orthopaedic surgeons versus nonorthopaedic practitioners

PURPOSE: To compare the percentages of normal magnetic resonance imaging (MRI) examination results and clinically significant knee abnormalities in patients referred for MRI of the knee by orthopaedic surgery residents and staff with those of patients referred by nonorthopaedic practitioners. TYPE OF STUDY: Retrospective review of MRI findings. METHODS: MRI reports of 754 patients (454 men and 300 women) were retrospectively reviewed; 373 patients were referred from the Department of Orthopaedic Surgery and 381 patients were referred from nonorthopaedic practitioners. The number of normal examination results, meniscal and ligament tears, chondral abnormalities, and Baker's cysts was tabulated and analyzed using a X-square injury analysis. RESULTS: The rate of normal results for nonorthopaedic practitioners was 33.9% (129 of 381) compared with 15.3% (57 of 373) for orthopaedic surgeons (P <.001). Nonorthopaedic surgeons referred 69.4% (129 of 186) of the patients who had normal examination results. The positive finding for a lateral meniscus tear was 29.2% (109 of 373) for orthopaedic surgeons compared with 19.1% (73 of 381) for nonorthopaedic practitioners, which was statistically significant (P =.002) in regard to the distribution of injuries. No difference was found in other abnormalities assessed. CONCLUSIONS: Patients referred by nonorthopaedic practitioners had significantly more normal knee MRI examination results than did those referred by orthopaedic surgeons.