RESTORATION OF THE SEAL FUNCTION OF THE ACETABULAR LABRUM: IN VITRO STUDY

An effective acetabular labrum is able to create a seal between the peripheral and central compartment of the hip joint. The goal of this study was to determine the effects of labral tears, repair and labrectromy on labrum function by using a navigation system and a load cell. The hip joint center displacement (mm) and the distraction load (N) was measured in 8 cadaveric hips during distraction maneuvers. These measurements were repeated after creating an anterolateral tear, cercalge repair, vertical mattress repair and labrectomy, respectively. Compared to the intact condition, 3% and 15% higher displacement was provoked during distraction test after labral–chondral separation and labrectomy. Moreover, significantly less force was required to distract the femur after cercalge repair (25%), vertical mattress repair (22%) and labrectomy (40%). A breach of the integrity of labral function was shown to lead to decreased femoral stability relative to the acetabulum during extreme ranges of motion.