Superficial part of tibial collateral ligament
Pars superficialis ligamenti collateralis tibialis
- Synonym: Superficial part of medial collateral ligament of knee
- Acronym: sMCL
- Related terms: Superficial part of medial collateral ligament
Definition
The superficial part of the tibial collateral ligament (superficial medial collateral ligament; sMCL ), is a key stabilizer of the medial aspect of the knee. It has a consistent anatomical structure and attachment pattern.
The sMCL originates from the medial epicondyle of the femur, specifically 3.2 mm proximal and 4.8 mm posterior to the medial epicondyle. It extends distally and has two distinct attachment sites on the tibia. The proximal tibial attachment is located approximately 42 mm below the tibial plateau, while the distal attachment is about 61.2 mm distal to the knee joint.
The sMCL is composed of two layers of collagen fibers: an unidirectional fibrous layer and a multidirectional fibrous layer, which decrease in thickness distally.This ligament is near-isometric, meaning it maintains a relatively constant length throughout the range of knee motion, which is crucial for its function in stabilizing the knee during various activities.
References
1.The Anatomy of the Medial Part of the Knee.LaPrade RF, Engebretsen AH, Ly TV, et al.The Journal of Bone and Joint Surgery. American Volume. 2007;89(9):2000-10. doi:10.2106/JBJS.F.01176.
2.The Bone Attachments of the Medial Collateral and Posterior Oblique Ligaments Are Defined Anatomically and Radiographically.Athwal KK, Willinger L, Shinohara S, et al.Knee Surgery, Sports Traumatology, Arthroscopy : Official Journal of the ESSKA. 2020;28(12):3709-3719. doi:10.1007/s00167-020-06139-6.
3.Anatomical Evaluation of the Superficial Medial Collateral Ligament Distal Tibial Attachment of the Knee.Kikuchi K, Tabuchi K, Inoue S, et al.Clinical Anatomy (New York, N.Y.). 2024;. doi:10.1002/ca.24192.
4.How Isometric Are the Medial Patellofemoral, Superficial Medial Collateral, and Lateral Collateral Ligaments of the Knee?.Victor J, Wong P, Witvrouw E, Sloten JV, Bellemans J.The American Journal of Sports Medicine. 2009;37(10):2028-36. doi:10.1177/0363546509337407.
