medial collateral ligament injury

Medial collateral ligament injuries are one of the most common ligamentous injuries of the knee.

Epidemiology

Medial collateral ligament injuries are very common in athletes and it is likely that many low-grade medial collateral ligament injuries are unreported .

Risk factors

Common risk factors for medial collateral ligament injury include contact and non-contact sports such as:

football (soccer)
rugby / American football
martial arts
skiing

Clinical presentation

Usual complaints are medially located knee pain after acute trauma and the sensation of popping or giving way at the moment of injury. On a physical exam, a perceived medial joint opening in 30° flexion on valgus stress is indicative of a medial collateral ligament injury .

Pathology

Medial collateral ligament injuries range from a minor sprain, over tear and disruption of the superficial portion to complete disruption including the deep portions of the medial collateral ligament .

Associations

medial meniscal tears
anterior cruciate ligament tear
posteromedial corner injury
posterior cruciate ligament injury (rare)
Complications
valgus instability
rotatory instability
Pellegrini-Stieda syndrome
Stener lesion of the medial collateral ligament in case of distal injury

Mechanism

Medial collateral ligament injury or tears are usually the results of valgus stress , but different mechanisms can result in characteristic associated injury patterns :

direct impact on the lateral knee: isolated medial collateral ligament injury
high impact valgus force: medial collateral ligament, posterior oblique ligament and anterior cruciate ligament injury
valgus force and external rotation: medial collateral ligament and posteromedial corner injury
valgus force and hyperextension: medial collateral ligament and posterior cruciate ligament injury

Location

Most medial collateral ligament tears are proximal or distal.

Radiographic features

Imaging in medial collateral injuries is usually done if muli-ligamentous or meniscal injuries are suspected .

Plain radiograph / CT

Plain radiographs are of limited value, avulsion injuries of the femoral condyle can sometimes be seen. Rarely an avulsion injury of the meniscotibial component (coronary ligament) of the deep medial collateral ligament can be seen (reverse Segond fracture).

MRI

The most obvious sign of medial collateral ligament injury is its discontinuity in case of a partial or complete tear. Other signs include a wavy form of the ligament.

Injury of the deep portions of the medial collateral ligament is evident as high-signal intensity, swelling and discontinuity of the medial meniscofemoral and mensicotibial ligaments or an avulsion injury of the meniscotibial ligament (reverse Segond fracture).

Medial collateral ligament injuries can be graded on MRI according to the following grading scheme:

medial collateral ligament injury grading

In addition, MRI allows the depiction of associated injuries as bone bruises, posterior oblique ligament and anterior cruciate ligament injuries as well as meniscal tears .

Radiological reporting

In case of medial collateral injury the report should include the following:

medial collateral ligament injury grading
avulsion injuries (femoral avulsion, reverse Segond fracture)
displacement of torn fibers anterior to pes anserinus or into the joint space
possible concomitant injury of the posterior oblique ligament
possible concomitant anterior cruciate ligament tear or posterior cruciate ligament injury
associated meniscal tears
possible posteromedial corner injury

Treatment and prognosis

Grade 1, grade 2 and isolated grade 3 medial collateral ligament injuries are usually treated conservatively, including early mobilization and exercise therapy, taping, physical therapy, nonsteroidal anti-inflammatory drugs and orthotic management as a hinged knee brace.

Grade 1 and 2 injuries have usually favorable outcomes with a return to work/return to sport as early as after 10-20 days post-injury . Most grade 3 injuries (>75%) are associated with other ligamentous injuries, with anterior cruciate ligament injury being most common and therefore might need different management. But even in combined anterior cruciate/medial collateral ligament injuries ACL reconstruction after conservative medial collateral ligament injury management seems to be a widely accepted method . Surgical repair should be considered in chronic medial collateral ligament tears, bony avulsion injuries, and Stener-like lesions of the medial collateral ligament

Differential diagnosis

Practical points

It is important that the distal parts of the medial collateral ligament are captured within the field of view since many tears are located either proximal or distal.

Assessment of the superficial and deep portions of the medial collateral ligament superficial and posterior oblique ligament is usually done on coronal and axial images .