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 thigh bone to your shin bone 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).
Good news on this one: most isolated MCL tears heal very reliably without surgery, because the MCL has a strong blood supply. That's a major difference from the ACL inside the knee, which doesn't 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 secondPain and tenderness along the inside of the knee, made worse by a gentle outward push (the valgus stress test). 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.
Treatment Path
how care progresses at OSI1
Hinged knee brace
A hinged knee brace gives the inside of the knee external support while the ligament heals. Mild tears move through their protected-motion phase quickly; complete tears need a longer protected period before returning to activity.
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 at OSI
if non-operative care isn't enoughIsolated MCL tears rarely need surgery. Surgical repair or reconstruction is considered for grade 3 tears that haven't 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.
Providers Who Treat MCL Sprain
sports-medicine team
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: