LCL and MCL injury

An LCL or MCL injury damages a side ligament of the knee, so treatment depends on stability, associated injuries and safe gradual rehabilitation. The LCL supports the outer side of the knee; the MCL supports the inner side.

A blow to the outside of the knee can stress the MCL, while force that pushes the knee outward or twists it can affect the LCL. Pain along the inner or outer joint line, swelling, tenderness and a feeling of giving way may occur. A clinician checks alignment, ligament stability, walking and the possibility of meniscus, bone or cruciate-ligament injury.

The label alone does not show how much the ligament is injured. Examination and, when appropriate, imaging help determine whether protection, supervised rehabilitation or specialist treatment is needed.

Reduce pivoting, cutting and contact activity while the knee is unstable or painful. Follow advice about weight-bearing, ice or compression, and use a brace only as directed; knee bracing can support protection but does not replace rehabilitation. Physiotherapy can restore knee motion, leg strength, balance and control. Increase activity in stages rather than testing the knee with a sudden match or hard run.

Have prompt assessment after a twisting injury with a pop, rapid swelling, marked instability or inability to bear weight. Seek urgent help if the foot becomes cold, pale, numb or weak, or if the knee is visibly deformed. Persistent locking, worsening swelling or pain that prevents sleep also warrants review before progressing activity.

Ask which ligament is involved, whether the knee is stable, how much weight you may place through the leg, and which exercises are appropriate now. Discuss when driving, work, running and contact sport can resume, and whether a return-to-sport programme would make the progression safer.