AB105. SOH23ABS_127. The utility of magnetic resonance imaging in assessing knee pain in patients over 45 years old

Background: Non-invasive advanced imaging modalities have gained traction over the past years as a tool for diagnosing bony and soft tissue injuries. Magnetic resonance imaging (MRI) in particular are used widely in the community settings for diagnosing both traumatic and atraumatic knee pain. One of the major aetiologies of atraumatic knee pain is osteoarthritis (OA). According to the National Institute for Health and Care Excellence (NICE) guidelines, OA is diagnosed clinically when an individual more than 45 years old presents with history of activity-related joint pain, and has no morning joint-related stiffness lasting beyond 30 minutes. The use of imaging was not recommended in the guidelines for the diagnosis of OA. However, many patients were referred to the orthopaedic services with MRI and X-rays done in the community prior to specialist review. Plain film knee X-ray alone has a sensitivity of 91% and specificity of 86% in aiding the diagnosis and assessing the severity of OA. On the other hand, MRI knee has a sensitivity of 61% and specificity of 82% on diagnosing OA.

Methods: In this study, we looked into all orthopaedic consultants referral in Tallaght University Hospital in a 12-month period.

Results: Out of all community referrals, 130 patients over 45 years old referred for knee pain were identified. They were further stratified into patients undergone plain film X-ray alone prior to referral, MRI alone, versus patients undergone both X-ray and MRI prior to referral.

Conclusions: We have studied the cost effectiveness of patients receiving scans with multiple modalities in the community and the impact on our clinical practise.

Keywords: Arthroplasty; community referral; knee pain; magnetic resonance imaging (MRI); osteoarthritis (OA)