Fibrocartilagenous tissue
Attached to transverse acetabular ligament anteriorly and posteriorly
Thin anteriorly and thick posteriorly
Recesses and variations:
Posterior inferior sublabral sulcus (recess): Seen superior to transition between labrum and tranverse ligament. Not to be confused for posterior labral tear on axials
Perilabral recess (sulcus): Between labrum and capsule on coronal images, seen on midsagittal images.
Transverse ligament-labral sulcus (recess): between transverse ligament and labrum, seen anteriorly or posteriorly. Seen on coronal and sagittal
Anterosuperior cleft: seen on coronal and sagittal images. Usually seen on only one image. Increased association with DDH
MR appearance:
Triangular in 70%; but may be round, flat, irregular or absent normally
References:
1.Resnick et al. Internal dergangements of joints. 2nd edition. Saunders Elsevier. 2007
