Lateral Acetabular Coverage Predicts the Size of the Hip Labrum

Tigran Garabekyan; Zachary Ashwell; Vivek Chadayammuri; Mary Kristen Jesse; Cecilia Pascual-Garrido; Brian Petersen; Omer Mei-Dan

doi:10.1177/0363546516634058

Lateral Acetabular Coverage Predicts the Size of the Hip Labrum

Am J Sports Med. 2016 Jun;44(6):1582-9. doi: 10.1177/0363546516634058. Epub 2016 Mar 17.

Authors

Tigran Garabekyan¹, Zachary Ashwell², Vivek Chadayammuri³, Mary Kristen Jesse², Cecilia Pascual-Garrido¹, Brian Petersen⁴, Omer Mei-Dan⁵

Affiliations

¹ Division of Sports Medicine and Hip Preservation, Department of Orthopaedics, University of Colorado School of Medicine, Aurora, Colorado, USA.
² Division of Musculoskeletal Radiology, Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado, USA.
³ University of Colorado School of Medicine, Aurora, Colorado, USA.
⁴ Division of Musculoskeletal Radiology, Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado, USA Inland Imaging, Spokane, Washington, USA.
⁵ Division of Sports Medicine and Hip Preservation, Department of Orthopaedics, University of Colorado School of Medicine, Aurora, Colorado, USA omer.meidan@ucdenver.edu.

PMID: 26989071
DOI: 10.1177/0363546516634058

Abstract

Background: Bony morphological abnormalities of the hip joint are often accompanied by adaptive soft tissue changes. These adaptive changes, if better understood and characterized, may serve to inform clinical decision making.

Purpose: To investigate the correlation between the size of the hip labrum and lateral acetabular coverage in patients at our hip preservation clinic.

Study design: Cross-sectional study; Level of evidence, 3.

Methods: A cohort of 236 patients seen at a dedicated hip preservation service between June 2013 and June 2015 were retrospectively analyzed. Patients were grouped according to the degree of acetabular coverage, as measured by the lateral center-edge angle (LCEA): normal acetabular coverage (25°-39.9°), acetabular overcoverage (≥40°), borderline dysplasia (20°-24.9°), and frank dysplasia (<20°). Preoperative magnetic resonance imaging was utilized to measure the length of the labrum at 3 locations: laterally, anteriorly, and anteroinferiorly.

Results: Frankly dysplastic and borderline dysplastic hips exhibited larger values of labral length at all locations when compared with hips with normal acetabular coverage (P < .001) or acetabular overcoverage (P < .001). Interestingly, mean labral length values in frank dysplasia were statistically similar to corresponding measurements in borderline dysplasia. In hips with frank dysplasia, borderline dysplasia, or normal acetabular coverage, labral length was consistently greatest at the lateral labrum and correspondingly lowest at the anteroinferior labrum (P < .001). In hips with acetabular overcoverage, labral length did not vary significantly between the lateral, anterior, and anteroinferior locations. Multivariate analyses confirmed LCEA to be the strongest predictor of labral length, irrespective of measurement location.

Conclusion: Patients with borderline dysplasia and frank dysplasia exhibited increased values of labral length in the weightbearing zone, potentially indicating a compensatory reaction to the lack of bony coverage. Labral length may serve as an instability marker and inform clinical decision making for patients with borderline dysplasia.

Keywords: dysplasia; femoroacetabular impingement; hip; hip arthroscopic surgery; labrum.

MeSH terms

Acetabulum / diagnostic imaging*
Adult
Cross-Sectional Studies
Female
Hip Dislocation / diagnostic imaging*
Humans
Male
Middle Aged
Retrospective Studies
Young Adult