Objectives: The aim of the study reported here was to investigate whether the use of magnetic resonance imaging (MRI) impacts on the clinical management of patients presenting with chronic knee problems, reduces costs, and improves patient outcome.

Methods: A single-center randomized controlled trial was conducted. Patients attending with knee problems in whom surgery was being considered were randomized either to investigation using an MRI scan or to investigation using arthroscopy. The study investigated benefits in terms of avoidance of surgery and patient health-related quality of life (using SF-36 and EQ-5D). Costs were assessed from the perspectives of the National Health Service and patients. All analyses were by intention to treat.

Results: The trial recruited 118 patients. No statistically significant differences were found between groups in terms of health outcome. However, the use of MRI was associated with a positive diagnostic/therapeutic impact: a significantly smaller proportion of patients in the MRI group underwent surgery (MRI=0.41, No-MRI=0.71; p value=.001). There was a similar mean overall cost for both groups.

Conclusions: The use of MRI in patients with chronic knee problems, in whom surgery was being considered, did not increase costs overall, was not associated with worse outcomes, and avoided surgery in a significant proportion of patients.