images/isrrt/16H45 DR JN CAKIC RM 1A SESSION 3 FRIDAY.pdf

Labral tearsLabral tears Twisting injury; degeneration; orcombination Predisposing morphology(dysplasia ⇄ impingement) 55% associated articular damage MRI arthrogrambest at showing labral pathologyRole of LabrumRole of LabrumExtension of Bony Acetabulum33% volume , 22% surface areaSuction effectTear loss of suction effect Resulting in relative instability May result in capsular attenuation and laxityConsolidation– gradual compression of thecartilage layers as interstitial fluidis expressed from thecollagenous/ proteoglycan-richsolid matrix of tissueRole of LabrumRole of LabrumMotion of the femur relative tothe acetabulum,vertically (a)laterally (b).The cartilage layerscompress appr. 40%quicker if the labrum isremovedCartilage contact stressDark grey – intact labrumLight grey – without labrumContact stressesin acetabular cartilageincrease with time, andup to 92% higher in theabsence of the labrum10