Correlation of Magnetic Resonance Arthrography with Revision Hip Arthroscopy

Background Arthroscopic approaches for the diagnosis and treatment of hip disorders are well established; however, there are limited data regarding revision hip arthroscopy. There have been several studies evaluating the findings of MR arthrography with primary hip arthroscopy, but to our knowledge, no study has evaluated the diagnostic value of MR arthrography before revision hip arthroscopy.

Questions/purposes We obtained sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MR arthrography to detect labral lesions, chondral lesions and loose bodies before revision hip arthroscopy.

Methods We performed a single-surgeon, retrospective review of 70 revision hip arthroscopies (62 patients) and assessed the association between MR arthrography findings and intraoperative findings. There were 43 females and 19 males with a mean age of 36 years (range, 17-59 years). Radiographic interpretation was performed by one of four fellowship-trained musculoskeletal radiologists at three institutions, who had at least 5 years of experience. Radiographic findings were compared with surgical findings by one of the authors for calculation of sensitivity, specificity, PPV, and NPV.

Results The sensitivity, specificity, PPV, and NPV of MR arthrography for detecting labral tears were 82%, 70%, 94%, and 39%, respectively. The sensitivity, specificity, PPV, and NPV of MR arthrography for detecting chondral damage were 65%, 90%, 94%, and 50%, respectively. The sensitivity, specificity, PPV, and NPV of MR arthrography for detecting loose bodies were 33%, 100%, 100%, and 88%, respectively.

Conclusions Our study showed the utility of MR arthrography to assist in the diagnosis and treatment of patients with ongoing or recurrent symptoms who have had prior hip arthroscopy. Our data show that MR arthrography is superior at ruling in, rather than ruling out, labral lesions, chondral lesions, and loose bodies, as there were studies interpreted as normal which in fact showed disorders.

Level of Evidence Level III, diagnostic study. See the Instructions for Authors for a complete description of levels of evidence.