Morphological study on the acetabular labrum.

For the diagnosis and treatment of the labral pathology, the cross sectional morphology of the labrum is needed. Fifty-four labra (male:female=44:10) from 32 adult Korean cadavers were cut in radial and perpendicular fashions to their longitudinal axis. Each labrum was divided into 8 segments, resulting 8 equally distanced points. To analyze the 432 cut surfaces, which consisted of 378 labra and 54 transverse acetabular ligaments cut surfaces, all dimensions of the cut surfaces were measured, and the attachment patterns, including the sublabral slit, observed. The shapes of the cut surfaces were classified into four types (3 subtypes of triangle and 1 quadrangle) and the attachment patterns into five types. At the anterior portion of the labrum, which other studies reported as the predilection area for labral tears, there were several common findings: 1) Tall triangular shapes were dominant (61.1%) or relatively common type (25.9%). 2) The average heights of the labrum were longer (7.4 and 7.0 mm) than at the other sites (4.0 - 6.8 mm). 3) The attachment types with no extra-extended portion (68.5%) and sublabral slits (39.0%) were most commonly observed. It was concluded that there were different types of cut surface and attachment patterns of the acetabular labrum, and these findings had a tendency to be distributed with some labral tears. These anatomical data are believed could be useful in the management of an acetabular labral pathology.