Assistant
Definition
By Gregory R. Waryasz, MD
The arcuate ligament of the musculoskeletal system is characterized by being related to the fabella, a bone that may or may not be present in the lateral head of the gastrocnemius origin.
It is part of the knee joint. It consists of fibrous dense regular connective tissue of collagen fibers.
Its unique structural feature is that it forms the arcuate complex with the fibers of the popliteus origin. The arcuate ligament is Y-shaped. It originates at the posterior fibular head and passes over the popliteal tendon to then become continuous with the oblique popliteal ligament in the posterior knee.
The arcuate ligament as well as all other bones, muscles, and ligaments of the body are derived of mesodermal origin in the embryo.
The function of the arcuate ligament strengthens the joint capsule posterolaterally.
Common diseases include congenital absence, and tears.
Congenital absence of the arcuate ligament occurs when there is a large fabella. This makes the fabellofibular ligament more robust.
Commonly used diagnostic procedures include clinical history, physical exam, x-ray, and MRI.
It is usually treated with surgery or nonoperative methods depending upon what other structures are injured. The absence of the arcuate ligament does not require treatment.
References
Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.
Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.
Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.