Magnetic resonance arthrography for femoroacetabular impingement surgery: is it reliable?

Abstract

BackgroundMagnetic resonance arthrography (MRA) is commonly used to demonstrate injury to the labrum and hyaline cartilage in patients with femoroacetabular impingement (FAI). The purpose of this study was to assess the diagnostic correlation between MRA and findings at arthroscopic and open surgery.Materials and methodsMRA reports of 41 hips with symptomatic FAI were reviewed and compared with subsequent intraoperative findings (n = 21 surgical dislocations and n = 20 therapeutic hip arthroscopies). Each case was assessed for the presence of a cam deformity, a cartilage lesion of the femoral head, an os acetabuli, an injury to the labrum and injury to the acetabular cartilage. Results were collected prospectively in a cross-table and analysed retrospectively for sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).ResultsThe sensitivity, specificity, PPV and NPV in the presence of reported cam-type deformity or an os acetabuli were 100 %. In the presence of cartilage lesions of the femoral head, the values were 46, 81, 55 and 73 %, respectively. For labral tears, the values were 91, 86, 97 and 67 %. In the presence of acetabular cartilage injuries, the values were 69, 88, 78 and 81 %, respectively.ConclusionsMRA appears to be an efficacious imaging modality in the evaluation of labral tears, cam-type impingement lesions and os acetabuli of the hip. MRA is less efficacious in the diagnosis of cartilage abnormalities in the hip, both femoral and acetabular. Researchers should focus on further improvements in imaging techniques in order to give reliable preoperative information to the surgeon.

Diagnostic accuracy of clinical tests for the diagnosis of hip femoroacetabular impingement/labral tear: a systematic review with meta-analysis

“…Four studies (n=188 participants)65 68 79 81 investigated the use of the FADDIR test with MR angiogram (MRA) reference standard, four studies (n=319 participants)68 69 71 76 investigated the use of the FADDIR test with surgery reference standard, and two studies (n=27 participants)63 74 investigated the use of the Flex IR test with surgery reference standard.…”

No Regeneration of the Human Acetabular Labrum After Excision to Bone

“…Because we performed a resection to bone, it is difficult to compare our results with other studies where the amount of resection is unspecified [1,3,5,6,11,18,29,34,38,53] and was probably limited to partial débridement in many cases. We attempt to repair most labral tears, but the patients here had no option other than reconstruction with a graft, a procedure we had not adopted at the time.…”

“…Abrams et al [1] found a positive relationship between age and the presence of ''inhomogeneous regrowth'' of the labrum, and the average age of their subjects was 29 years. The condition of the labrum after various hip preservation procedures has been examined by arthroscopy [1,18,29,34,53], MRA [3,5,11,18], and during open procedures [6,38]. Overall, these reports contain only limited information on the extent of the initial labral resection.…”

Evaluation of Hip Pain in Young Adults

“…Magnetic resonance imaging is especially useful in the evaluation of avascular necrosis, a cause of symptoms, as well as in the evaluation of femoral neck stress fractures, 21 whereas MRA may be most helpful in the evaluation of labral tears, cam-type lesions, and os acetabula, with a sensitivity and specificity for detecting labral tears of 81% and 51%, respectively. 45 It should be noted, however, that for patients for whom the physician has an already high clinical suspicion of labral pathology, MRA has a poor negative predictive value and thus is unhelpful in ruling out labral lesions. 46 Imaging findings may be helpful in preoperative planning, especially with regard to determining the need for labral repair and potential femoral head or acetabular microfracture.…”