What should you know about MCL and PCL injury?

The MCL supports the inner side of the knee. The PCL helps prevent the shinbone from moving too far backwards beneath the thighbone. A force to the front of a bent knee, a twisting event or a collision can injure one or both. Symptoms may include deep knee pain, swelling, difficulty using stairs and a feeling that the knee shifts. A clinician compares both knees, checks circulation and nerve function, and may use magnetic resonance imaging or X-rays to look for ligament and bone involvement.

Stop activities that involve contact, jumping or turning, and use support if walking is uncomfortable. Keep the knee in a comfortable position and follow the examination plan rather than testing its stability yourself. A clinician may suggest [Knee Bracing](/treatments/non-surgical-orthopedics/knee-bracing/) and a staged exercise plan. [Physiotherapy](/treatments/physiotherapy-and-rehabilitation/physiotherapy/) can address swelling, range of motion, thigh strength and controlled balance. Combined injuries sometimes need specialist planning before active rehabilitation progresses.

Seek prompt medical assessment after a substantial knee impact, especially when weight bearing is difficult, swelling appears quickly, or the knee repeatedly gives way. Urgent care is appropriate for a deformed knee, severe escalating pain, a numb or weak foot, or a foot that is unusually cold or pale. Do not drive if you cannot control the pedals safely.

Are both ligaments injured, and how severe is each injury? Is there damage to the meniscus, cartilage, nerves or blood vessels? Should I use a brace or crutches? What range of motion and strengthening work is safe now, and who will coordinate follow-up?