The objective of this study was to use an optimized noncontrast MRI protocol to identify hip labral pathology, including labral tears and paralabral cysts.
In this prospective prevalence study, 42 hips in asymptomatic patients with an average of 34 years old (range 27-43) were imaged with optimized noncontrast MRI scans. Two fellowship trained musculoskeletal radiologists interpreted the scans at two different points in time and commented on the presence of labral pathology including paralabral cysts. The results were analyzed for both interobserver and intraobserver reliability.
Acetabular paralabral cysts were identified in 11/42 (26.2%) and 9/42 (21.4%) of the hips by the two respective radiologists with an interobserver reliability of 90.5% (kappa value of 0.74) and intraobserver reliability of 95.2% (kappa value of 0.87). In addition, acetabular labral tears were identified in 35/42 (83.3%) and 33/42 (78.5%) of the hips with an interobserver reliability of 90.5% (kappa value of 0.70) and intraobserver reliability of 95.2% (kappa value of 0.83).
Acetabular labral tears, as a potential source of hip pain, have received a great deal of attention in recent literature. The gold standard for identifying acetabular labral tears is hip arthroscopy, but recent advances in optimized noncontrast MRI have proven effectiveness in identifying intra-articular hip pathology without the invasive nature of hip arthroscopy or gadolinium enhanced arthrography. Acetabular paralabral cysts have also been shown to be associated with underlying labral tears, similar to meniscal cysts in the knee or labral cysts in the shoulder. We report the previously undescribed prevalence of acetabular paralabral cysts and prevalence of labral tears in a young, asymptomatic population. This emphasizes the importance of correlating patient symptoms and using diagnostic, and potentially therapeutic, intra-articular injections when evaluating patients with hip pain and radiographic abnormalities as defined by MRI criteria.
© 2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.