MRI may accurately measure hip labral width in patients in femoroacetabular impingement
Published results showed MRI may be an accurate tool in measuring hip labral width in patients with femoroacetabular impingement, with strong agreement between radiologic and arthroscopic measurements, as well as no significant differences between MRI modalities.
Daniel J. Kaplan, MD, and colleagues performed preoperative MRIs for 51 patients undergoing hip arthroscopy for femoroacetabular impingement who had MRI availability in a picture archiving and communication system; performance on a 1.5T or 3T MRI or 3T magnetic resonance angiography; and adequate quality and lack of labrum ossification. Using an established acetabular clockface paradigm, researchers performed intraoperative labral width measurements and two-blinded musculoskeletal fellowship-trained radiologists performed MRI measurements at standardized locations. These standardized locations included the 11:30 position on coronal proton density sequence, the 3 o’clock position on axial oblique proton density sequence and the 1:30 position on sagittal fat-suppressed proton density, according to researchers.
Researchers compared intraoperative and radiographic labral width measurements using an intraclass correlation coefficient, absolute agreement and two-way random effects model, while interrater reliability using the same intraclass correlation coefficient was used to compare radiologists’ measurements.
Results showed patients had an average labrum width of 5.8 mm at the 3 o’clock position, of 6.3 mm at the 11:30 position and of 6 mm at the 1:30 position by arthroscopic measurements. Researchers also found an average labrum width of 6.3 mm, 6.7 mm and 6.1 mm at the 3 o’clock, 11:30 and 1:30 positions by MRI, respectively. Researchers noted all good to excellent intraclass correlation coefficient agreements between surgeon and radiologist and all good to excellent MRI modalities between radiologists. Radiologists had stronger interrater agreement at each position than agreement between intraoperative assessment and radiologic assessment, according to results.
Results showed excellent 3T MRI and arthroscopic agreement and good interrater radiologic agreement for the 3 o’clock position. Researchers also found good arthroscopic vs. radiologic agreement at the 11:30 position but excellent radiologic interrater assessment. Magnetic resonance arthrography showed higher arthroscopic and radiologic agreement at the 3 o’clock and 11:30 positions compared with the 1:30 position, according to results. However, researchers noted excellent interrater radiologic improvement at all positions.
“Results from this study demonstrate that hip labral width may be assessed preoperatively via MRI,” Kaplan, a resident in the department of orthopedic surgery at NYU Langone Health, told Healio Orthopedics. “This additional diagnostic information may assist with preoperative planning and could help guide the decision to repair or reconstruct the labrum.” – by Casey Tingle
Disclosure: Kaplan reports no relevant financial disclosures.