Magnetic Resonance Arthrogram Referrals by Subspecialist and Non-Subspecialist Orthopaedic Surgeons: What are the Findings?

BACKGROUND: Although subspecialist orthopaedic surgeons usually request Magnetic Resonance Arthrogram (MRA) examinations, some orthopaedic surgeons may request this examination for a body part that is different from their subspecialty. The purpose of the study is to compare the MRA and the clinical findings in the subspecialist and non-subspecialist groups. METHOD: Retrospective analysis of MRA examinations over a 6-month period. Findings were compared with the clinical information. RESULTS: There were 144 examinations (69 shoulder, 42 wrist and 33 hip). 85% of these were subspecialist referrals; 60% of them showed findings compatible with the clinical diagnosis. 15% of the MRA examinations were non-subspecialist referrals; 52% of them correlated with the clinical findings. Overall, clinical information agreed with MRA findings for shoulder labral tears, hip labral tears and wrist triangular fibrocartilage complex tears in 63.3%, 64.5% and 61.5% respectively. The subspecialist group were more accurate than the non-subspecialist group in diagnosing hip labral tears (68% vs. 50%) and triangular fibrocartilage complex tears (62.5% vs. 50%). On the contrary, shoulder MRA and clinical findings correlated better in the non-subspecialist group (77.8%) compared to the subspecialist group (63.3%). However, the small number of requests generated by the non-subspecialist group may affect the results. Suspected scapholunate ligament injury showed low correlation with MRA at 26.7% (33.3% in the subspecialist group and 0% in the non-subspecialist group). CONCLUSION: Generally, the clinical findings are more accurate in the subspecialist referrals when compared to MRA findings and therefore a subspecialist referral is preferred. The low agreement between clinically suspected scapholunate ligament injuries and wrist MRA probably reflects the relative difficulty in establishing this diagnosis clinically.