title: Accuracy of magnetic resonance studies in the detection of chondral and labral lesions in femoroacetabular impingement: systematic review and meta-analysis.
abstract: Several types of Magnetic resonance imaging (MRI) are commonly used in imaging of femoroacetabular impingement (FAI), however till now there are no clear protocols and recommendations for each type. The aim of this meta-analysis is to detect the accuracy of conventional magnetic resonance imaging (cMRI), direct magnetic resonance arthrography (dMRA) and indirect magnetic resonance arthrography (iMRA) in the diagnosis of chondral and labral lesions in femoroacetabular impingement (FAI).
  
  
  
  A literature search was finalized on the 17th of May 2016 to collect all studies identifying the accuracy of cMRI, dMRA and iMRA in diagnosing chondral and labral lesions associated with FAI using surgical results (arthroscopic or open) as a reference test. Pooled sensitivity and specificity with 95% confidence intervals using a random-effects meta-analysis for MRI, dMRA and iMRA were calculated also area under receiver operating characteristic (ROC) curve (AUC) was retrieved whenever possible where AUC is equivocal to diagnostic accuracy.
  
  
  
  The search yielded 192 publications which were reviewed according inclusion and exclusion criteria then 21 studies fulfilled the eligibility criteria for the qualitative analysis with a total number of 828 cases, lastly 12 studies were included in the quantitative meta-analysis. Meta-analysis showed that as regard labral lesions the pooled sensitivity, specificity and AUC for cMRI were 0.864, 0.833 and 0.88 and for dMRA were 0.91, 0.58 and 0.92. While in chondral lesions the pooled sensitivity, specificity and AUC for cMRI were 0.76, 0.72 and 0.75 and for dMRA were 0.75, 0.79 and 0.83, while for iMRA were sensitivity of 0.722 and specificity of 0.917.
  
  
  
  The present meta-analysis showed that the diagnostic test accuracy was superior for dMRA when compared with cMRI for detection of labral and chondral lesions. The diagnostic test accuracy was superior for labral lesions when compared with chondral lesions in both cMRI and dMRA. Promising results are obtained concerning iMRA but further studies still needed to fully assess its diagnostic accuracy.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium. ahmed.saied@ugent.be.|Department of Orthopaedic Surgery, Mansoura University Hospital, Mansoura University, Mansoura, Egypt. ahmed.saied@ugent.be.
authors.forename: A M
authors.identifier: 0000-0002-1033-1490
authors.initials: AM
authors.lastname: Saied
authors.affiliation: Department of Physical Medicine and Rehabilitation, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Redant
authors.affiliation: Department of Orthopaedic Surgery, Mansoura University Hospital, Mansoura University, Mansoura, Egypt.
authors.forename: M
authors.initials: M
authors.lastname: El-Batouty
authors.affiliation: Department of Orthopaedic Surgery, Mansoura University Hospital, Mansoura University, Mansoura, Egypt.
authors.forename: M R
authors.initials: MR
authors.lastname: El-Lakkany
authors.affiliation: Department of Orthopaedic Surgery, Mansoura University Hospital, Mansoura University, Mansoura, Egypt.
authors.forename: W A
authors.initials: WA
authors.lastname: El-Adl
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Anthonissen
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Verdonk
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, De Pintelaan 185, B-9000, Ghent, Belgium.
authors.forename: E A
authors.initials: EA
authors.lastname: Audenaert
mesh_terms: D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging
keywords: Cartilage defect; Chondral lesion; Femoroacetabular impingement; Hip joint; Labral lesion; Magnetic resonance; Sensitivity; Specificity