Overview
what it is and why it mattersThe medial collateral ligament (MCL) is the cord-like ligament along the inside of your knee. It connects your femur (femur) to your tibia (tibia) and keeps the knee from buckling inward. MCL sprains are the most common knee ligament injuries, usually from a direct blow to the outside of the knee (which forces the inside open) or from any contact-sport play that pushes the knee inward. Severity is graded 1 (mild stretching), 2 (partial tear), or 3 (complete tear).
The good news: most isolated MCL tears heal very reliably without surgery, because the MCL has a strong blood supply. That is a major difference from the ACL inside the knee, which does not get enough blood flow to heal on its own.
Symptoms
what you may notice- Pain along the inner knee. Tenderness runs along the inside of the knee, from the thigh-bone attachment down toward the shin, worst right after the hit.
- Swelling on the medial side. Puffiness and bruising concentrate on the inner knee, in contrast to the diffuse swelling of an ACL tear.
- Feeling of instability. With a grade 2 or 3 tear the knee may feel loose or want to buckle inward, especially when changing direction or planting your foot.
- Stiffness and limited motion. Swelling and guarding make it hard to fully bend or straighten the knee in the first few days.
Diagnosis
exam first, imaging secondA focused physical exam of the knee, with pain and tenderness along the inside of the knee that gets worse when the joint is gently stressed. Swelling tends to be less dramatic than with an ACL tear. MRI grades the tear and looks for associated injuries, particularly the inside meniscus and the ACL. The combination of all three injured at once has a name: the unhappy triad.
How We Treat It
what we try first, in orderThe reassuring part of an MCL sprain is that most isolated tears heal on their own, because the ligament has a strong blood supply. The job of treatment is to protect the knee while that healing happens and to keep it from stiffening. The steps below are listed in the order we usually introduce them, and each one is added on top of the ones before, not instead of. Mild tears move through these phases quickly; complete tears need a longer protected period before returning to activity.
1
Hinged knee brace
A hinged knee brace gives the inside of the knee external support while the ligament heals.
2
Physical therapy
Range-of-motion work to keep the knee from stiffening, plus quad and hamstring strengthening, with a graded return to sport.
Surgical Options
if non-operative care isn't enoughIsolated MCL tears rarely need surgery. Surgical repair or reconstruction is considered for grade 3 tears that have not healed despite a real bracing trial, for combined ligament injuries (multiple knee ligaments torn at once), or when the MCL has pulled completely off the bone.
Frequently Asked
questions we hear in clinicWill my MCL heal without surgery?
Most isolated MCL tears do. The ligament has a strong blood supply, so it tends to heal reliably on its own with bracing and therapy. That is a major difference from the ACL inside the knee, which does not get enough blood flow to heal on its own. Isolated MCL tears rarely need surgery.
What causes an MCL sprain?
Usually a direct blow to the outside of the knee, which forces the inside open, or any contact-sport play that pushes the knee inward.
What do the grades mean?
MCL sprains are graded by severity: grade 1 is mild stretching, grade 2 is a partial tear, and grade 3 is a complete tear. Mild tears move through their protected-motion phase quickly, while complete tears need a longer protected period before returning to activity.
Do I need an MRI?
The diagnosis starts with the exam: pain and tenderness along the inside of the knee, made worse by a gentle outward push. An MRI grades the tear and looks for associated injuries, particularly the inside meniscus and the ACL. When the MCL, the meniscus, and the ACL are all injured at once, it has a name, the unhappy triad.
When is surgery considered?
Isolated MCL tears rarely need surgery. Surgical repair or reconstruction is considered for grade 3 tears that have not healed despite a real bracing trial, for combined ligament injuries when multiple knee ligaments are torn at once, or when the MCL has pulled completely off the bone.
Providers Who Treat MCL Sprain
sports-medicine team
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: