Transverse acetabular ligament
Ligamentum transversum acetabuli
Definition
The transverse acetabular ligament spans the inferior aspect of the acetabulum and bridges the acetabular notch, which is a gap found inferiorly within the margin of the hip bone’s acetabulum.
When the transverse acetabular ligament crosses the acetabular notch, it forms a small space between the ligament and the bone, facilitating the entry of nutrient vessels into the hip joint.
The transverse acetabular ligament (TAL) is composed of dense fibrous tissue and is continuous with the acetabular labrum, contributing to the stability of the hip joint by forming part of the load-bearing surface for the femoral head.[1]
Histologically, the TAL contains fibrocartilage, particularly at its bony attachments and near its inner surface where it faces the femoral head. This fibrocartilage is adapted to withstand compression, suggesting that the TAL shares some biomechanical properties with tendons and ligaments that wrap around bony pulleys.[2]
Radiographically, the midpoint of the TAL can be identified at the 7 o'clock position on the acetabular clockface, providing a consistent reference point for surgical procedures
References
Standring, S. and Gray, H. (2016). ‘Chapter 80: Pelvic girdle gluteal region and thigh’ in Gray’s anatomy The anatomical Basis of Clinical Practice. (41st ed.) New York: Elsevier, pp. 1339-1342.
Wobser, A.M., Adkins, Z. and Wobser, R.W. Anatomy, Abdomen and Pelvis: Bones (Ilium, Ischium, and Pubis) [Updated 2022 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519524/