Assessment of acetabular chondral damage and labral pathologies via direct MR arthrography: specialization matters

Abstract

Aims To compare the diagnostic accuracy of investigators from different specialities (radiologists and orthopaedic surgeons) with varying levels of experience of 1.5 T direct magnetic resonance arthrography (dMRA) against intraoperative findings in patients with femoroacetabular impingement syndrome (FAIS). Methods A total of 272 patients were evaluated with dMRA and subsequent hip arthroscopy. The dMRA images were evaluated independently by two non-hip-arthroscopy-trained orthopaedic surgeons, two fellowship-trained musculoskeletal radiologists, and two hip-arthroscopy-trained orthopaedic surgeons. The radiological diagnoses were compared with the intraoperative findings. Results Hip arthroscopy revealed labral pathologies in 218 (79%) and acetabular chondral lesions in 190 (69%) hips. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for evaluating the acetabular labral pathologies were 79%, 18%, 79%, 18%, and 66% (non-hip-arthroscopy trained orthopaedic surgeons), 83%, 36%, 83%, 36%, and 74% (fellowship-trained musculoskeletal radiologists), and 88%, 53%, 88%, 54% and 81% (hip-arthroscopy trained orthopaedic surgeons). The sensitivity, specificity, PPV, NPV and accuracy of dMRA for assessing the acetabular chondral damage were 81%, 36%, 71%, 50%, and 66% (non-hip-arthroscopy trained orthopaedic surgeons), 84%, 38%, 75%, 52%, and 70% (fellowship-trained musculoskeletal radiologists), and 91%, 51%, 81%, 73%, and 79% (hip-arthroscopy trained orthopaedic surgeons). The hip-arthroscopy trained orthopaedic surgeons displayed the highest percentage of correctly diagnosed labral pathologies and acetabular chondral lesions, which is significantly higher than the other two investigator groups (p < 0.05). Conclusion The accuracy of dMRA on detecting labral pathologies or acetabular chondral lesions depends on the examiner and its level of experience in hip arthroscopy. The highest values are found for the hip-arthroscopy-trained orthopaedic surgeons. Level of evidence Retrospective cohort study; III.

Gadolinium injected concurrently with anesthetic can result in false-negative diagnostic intra-articular hip injections

“…Moreover, the response to an intra‐articular injection has been shown to improve diagnostic accuracy of femoroacetabular impingement (FAI) in patients with atypical symptoms [9, 12, 19, 23]. In patients with suspected FAI, the combination of MRA and diagnostic hip injection can improve diagnostic accuracy [5, 22, 30] and these tests are often performed concurrently in a single injection to minimize the additional risk and procedural invasiveness to the patient. However, multiple authors have cautioned against interpreting diagnostic injection results in this setting, or have specifically excluded these patients from study, citing increased risk of false‐negative results due to post‐arthrography pain [2, 7, 15, 25, 26].…”