ePoster #803 - ISHA Annual Scientific Meeting 2016

Three-Dimensional Characterization Of Acetabular Morphology In Borderline Acetabular Dysplasia: Variable Deformity Patterns

Jeffrey J. Nepple, MD, St. Louis, MO UNITED STATES
James R. Ross, MD, Deerfield Beach, FL UNITED STATES
Asheesh Bedi, MD, Ann Arbor, MI UNITED STATES
John Clohisy, MD, St. Louis, MO UNITED STATES

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

FDA Status Cleared

Summary: Hips with radiographic borderline acetabular dysplasia demonstrate variable patterns of acetabular deformity, with anterosuperior deficiency occurring most commonly (30%).

Abstract:
Borderline hip dysplasia is a controversial and poorly understood clinically entity. A subset of patients with radiographic borderline hip dysplasia appear to have instability-based symptoms while other have impingement-based symptoms, as well as some patients potentially having both. The three-dimensional acetabular deformity in this population remains poorly understood. The purpose of the current study was to characterize the three-dimensional acetabular anatomy in patients with symptomatic borderline acetabular dysplasia. Methods: Twenty-five consecutive hips undergoing surgical treatment of symptomatic instability with radiographic evidence of borderline acetabular dysplasia were included. Preoperative CT scans were analyzed to characterize the acetabular anatomy relative to normative data. Results: The radiographic lateral center edge angle averaged 21.4 degrees (range 20 -24). A positive crossover sign was seen in 30% of hips and a positive posterior wall sign in 50% of hips. Cranial retroversion (1:00) was present in 15% of hips. The most common pattern of acetabular deficiency was anterosuperior (30% of hips), followed by isolated lateral (25%), posterosuperior (25%), and global (20%) deficiency. Regional anterior coverage averaged 36.7% (range 33.6-39.5%), lateral coverage averaged 55.5% (range 49.5-60.9%), and posterior coverage averaged 45.3% (range 39.9-53.1%). Total coverage averaged 36.5% (range 31.3-41.1%). Conclusions: Hips with radiographic borderline acetabular dysplasia demonstrate variable patterns of acetabular deformity, with anterosuperior deficiency occurring most commonly (30%). Lateral, posterior superior, and global acetabular deficiency patterns also commonly occur. Three-dimensional characterization of radiographic borderline acetabular dysplasia is valuable for precise characterization of underlying deformity to guide treatment decisions.