ePoster #1001 - ISHA Annual Scientific Meeting 2016

Labral Morphology Is Variable In The Young Adult Dysplastic Hip: An Mri-Based Analysis

Robert Staples, MD, St. Louis UNITED STATES
Jeffrey J. Nepple, MD, St. Louis, MO UNITED STATES
Travis Hillen, MD, St. Louis UNITED STATES
John Clohisy, MD, St. Louis, MO UNITED STATES

Washington University School of Medicine, St. Louis, MO, UNITED STATES

FDA Status Cleared

Summary: Variable size in variable in dysplastic hips undergoing periacetabular osteotomy, but does not correlate with radiographic parameters of dysplasia severity.

Abstract:
Background: Labral hypertrophy is commonly present in the young adult with symptomatic acetabular dysplasia and is viewed as a sign of hip instability. However, the variability in labral size and prevalence of labral hypertrophy have not been previously reported. Methods: Thirty consecutive patients with symptomatic acetabular dysplasia undergoing hip preservation surgery were identified. Preoperative MR arthrograms were performed on all patients according to a standardized protocol. Labral size was quantified as the length along the femoral head on axial, coronal, and sagittal T1 images at the center of the femoral head. The intraobserver (and interobserver ) reliability of measurements was determined to be 0.48 (0.57), 0.80 (0.61), and 0.78 (0.54) for axial, coronal, and sagittal images. Results: The maximal labral length average 11.3 + 3.0 mm (range 6.2 mm to 19.6 mm). The mean labral length was 9.7 mm on axial images, 9.6 mm on coronal images, and 8.4 on sagittal images. Maximum labral length was seen on axial (43%), coronal (30%), and sagittal (27%) images, respectively. Labral size greater than 8 mm was present in at least one plane in 90% of dysplastic hips, and greater than 10 mm in 67% of hips. Maximal labral size was not significantly correlated with measurements of lateral center angle, acetabular inclination, or anterior center edge angle (all p>0.15). Conclusions: Variable size in variable in dysplastic hips undergoing periacetabular osteotomy, but does not correlate with radiographic parameters of dysplasia severity. Further research is needed to fully understand the etiology and implications of labral hypertrophy