Medial Collateral Ligament Injection

Indications and Clinical Considerations

Medial collateral ligament syndrome is characterized by pain at the medial aspect of the knee joint. It is usually a result of trauma to the medial collateral ligament from falls with the leg in valgus and externally rotated, typically during snow skiing accidents ( Fig. 154.1 ). The medial collateral ligament is a broad, flat, bandlike ligament that runs from the medial condyle of the femur to the medial aspect of the shaft of the tibia, where it attaches just above the groove of the semimembranosus muscle attachment. It also attaches to the edge of the medial semilunar cartilage. The ligament is susceptible to strain at the joint line or avulsion at its origin or insertion.

Patients with medial collateral ligament syndrome experience pain over the medial joint and increased pain on passive valgus and external rotation of the knee. Activity, especially involving flexion and external rotation of the knee, makes the pain worse; rest and heat provide some relief. The pain is constant and is characterized as aching and may interfere with sleep. Patients with medial collateral ligament strain will demonstrate a positive valgus stress and Swain tests ( Figs. 154.2 and 154.3 ). Coexistent bursitis, tendinitis, arthritis, or internal derangement of the knee may confuse the clinical picture after trauma to the knee joint.

Plain radiographs are indicated for all patients with medial collateral ligament syndrome pain. On the basis of the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging and/or ultrasound imaging of the knee is indicated if internal derangement or occult mass or tumor is suspected as well as to confirm the diagnosis of suspected medial collateral ligament injury ( Fig. 154.4 ). Bone scan may be useful for identifying occult stress fractures involving the joint, especially if trauma has occurred.

Clinically Relevant Anatomy

The medial collateral ligament is a broad, flat, bandlike ligament that runs from the medial condyle of the femur to the medial aspect of the shaft of the tibia, where it attaches just above the groove of the semimembranosus muscle attachment ( Fig. 154.5 ). It also attaches to the edge of the medial semilunar cartilage. The medial collateral ligament is crossed at its lower part by the tendons of the sartorius, gracilis, and semitendinosus muscles. A bursa is between these tendons and the medial collateral ligament and is subject to inflammation if the ligament or tendons are traumatized.