Coronary Ligament Injury…an often overlooked cause of medial or lateral knee pain
A practitioner recently requested a post on the topic of coronary ligament injury…..
Named after the Latin word corona, meaning crown (referring to their crown-like shape), the coronary ligaments are two in number and are termed medial and lateral coronary ligaments. These often forgotten, but clinically important ligaments are in truth part of the fibrous capsule of the knee
The medial coronary ligament is that part of the capsule which connects the medial edge of the medial meniscus to the medial aspect of the medial tibial condyle just distal to the articular margin.
The lateral coronary ligament is that part of the capsule which connects the lateral edge of the lateral meniscus to the lateral aspect of the lateral tibial condyle just distal to the articular margin.
These ligaments are responsible for limiting rotation of the knee as well as for stabilizing the medial and lateral menisci. While they anchor the menisci to the tibia, they do allow for a controlled amount of anterior and posterior translation.
Clinically: Traumatic & Non-traumatic Injury
Injury to these structures is very common, however more commonly overlooked. Activities that particularly stress them involve rotation/torsion of the tibia on the femur as often occurs during sports such as dancing, martial arts, racquet sports, football, and soccer; particularly if the athlete has poor foot and/or knee alignment. Another pre-disposing factor is laxity in either the cruciate and/or collateral ligaments.
Injury to the coronary ligaments commonly stems from traumatic injury. For example, they are frequently ruptured in medial collateral ligament disruption and lateral collateral ligament complex tears; although injury to the structures can occur independently. Typically, the precipitating incident is a sudden and forceful medial or lateral twist of the knee occurring on a planted foot. The resultant pain is often sharp with sudden movements and may or may not be accompanied by mild swelling depending on the degree of the injury. In most cases flexion and extension ROM will remain full with discomfort at end range although with higher grades, effusion may restrict full end ranges.
As the coronary ligaments are not clearly described in most anatomy texts, many manual therapists are unaware of their significance. Injury to these structures are often confused with damage to other structures in the knee. For example, acute, traumatic injury is often misdiagnosed as meniscal tears, or collateral ligament sprains. Confounding the incidence of incorrect diagnoses is the misinterpretation of a widely utilized orthopedic test, namely ‘joint line tenderness.’ This test is performed by simply applying pressure to the medial or lateral joint line. Pain with pressure is often considered a positive test for meniscal tears/damage….however more often this represents injury to the collateral ligaments. This misinterpretation occurs, as coronary ligament damage can be present with meniscal injury, however from my clinical experience sole injury to the coronary ligaments is most often the case.
Perhaps even more important to manual practitioners are incidences of injury to these ligaments from non-traumatic factors. Such injuries can often develop slowly over time through constant pounding from some of the previously mentioned sports (in addition to distance running, especially if performed over inconsistent terrains). Clinically I have found these injuries to be very common and often mis-diagnosed for example as Iliotibial band syndrome at the lateral attachment to the knee. Chronic injury to the ligaments will result in connective tissue fibrosis/contraction, which then, in addition to causing pain, can limit proper translation of the menisci; this can theoretically lead to injury to the menisci, or the stabilizing ligaments of the knee due to altered biomechanics.
Diagnosis of injury to these ligaments can be challenging. In order to stress these ligaments, the practitioner should utilize tibial torsion as done when
performing the ‘passive medial or lateral rotation tests’ (for the medial and lateral coronary ligaments respectively. These tests are done simply by rotating the tibia on the femur by way of applying rotational force via the foot. For traumatic type injuries, this will often reproduce pain symptoms in the joint line. However these tests also stress many other structures. Thus, the application of specific clinical palpation techniques is often needed in conjunction with these tests….and is often the only diagnostic procedure for non-traumatic cases. As demonstrated in figure 2 which demonstrate passive medial rotation, the movement causes anterior translation of the medial tibial plateau thus exposing the joint line and allowing the practitioner to apply inferior pressure on the plateau’s coronary ligament (figure taken from FUNCTIONAL ANATOMIC PALPATION SYSTEMS™ Lower Limb seminar – which teaches advanced assessment/palpation of the ligaments).
- Manage histological components – inflammation, pain
- Limit connective tissue fibrosis – Functional Range Release™ following the acute phase
- If associated meniscal damage – Open operations to repair these structures are always indicated on the lateral side but the medial side usually heals and with it, the coronary ligament. The peripheral meniscal tears which may occur with severe medial collateral ligament ruptures are usually associated with damage to the coronary ligament. Open medial collateral repair or posteromedial repair must also address this peripheral meniscal avulsion and suture of the meniscus with either non-absorbable or Vicryl type sutures.
- Kinetic chain rehab as directed by examination
- Reduce connective tissue fibrosis and promote A-P meniscal motion – Functional Range Release™
- Kinetic chain rehabilitation as directed by examination