OBJECTIVE: To study the sensitivity of magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) for the diagnosis of acetabular labrum lesions and of hip cartilage lesions. METHODS: 90 patients (90 hips) were included, who had been submitted to hip videoarthroscopy between May 2004 and July 2007, at the Ultralitho Medical Center and at the Governador Celso Ramos Hospital, both in the city of Florianópolis, State of Santa Catarina. Of the 90 patients, 25 (27.7%) were submitted to MRI without contrast, 54 (60%) were submitted to MRA, and 11 (12.22%) were submitted to both MRI and MRA. In patients submitted to MRA, the contrast was given together with a local anesthetic (bupivacaine 0.5%, or ropivacaine 1%, without adrenaline). Acetabular labrum lesion and chondral lesion were seen under videoarthroscopy in all cases. RESULTS: The authors found higher sensitivity to diagnose acetabular labrum lesion with MRA (96.9%) than with MRI (86.1%), such difference being statistically significant. With respect to the diagnosis of lesion in the hip cartilage, RMA sensitivity was 78.4%, and MRI sensitivity was 55.5%, which is also a statistically significant difference. There was a higher percent of false negative results in MRI, in the diagnosis of both labral lesion and chondral lesion. No false positive was found in this series. The introduction of a local anesthetic to perform MRA showed pain relief in 56.9% of the cases. CONCLUSION: The authors conclude that MRA presented higher diagnostic sensitivity than MRI for acetabular labrum lesions and hip cartilage lesions. Lack of difference in pain or the worsening of pain after introduction of a local anesthetic for MRA was not considered a predictive factor for intra-articular lesions.
Magnetic resonance imaging; Arthroscopy; Hip joint
