If you suffer a knee injury, what do you do about it? Should you be concerned? On one hand, you could give it a few days to see if it gets better on its own. How can you know if you risk making the problem worse? In this Ask Dr. Geier video, I offer four signs you have a serious knee injury that could require surgery.


If you have a knee that is much more swollen than the opposite knee, especially if the swelling developed soon after you got hurt, then it could be a sign of structural damage. While a small amount of swelling could be normal or a sign of inflammation in the knee, a knee that is really swollen and much larger than the other knee could represent a fracture, torn ACL or other ligament or some other damaged structure.

Inability to fully straighten your knee

Pain can make it difficult for you to straighten your knee. But being unable to get your knee completely flat can be a sign of an injury like an ACL tear or meniscus tear.

Man with knee pain from a serious knee injury

Locking of the knee

Locking is a term orthopedic surgeons use to describe a knee that gets stuck in a certain position. Maybe you can straighten it to a certain point, but it gets stuck around 30 degrees short of fully straight. Or you can’t bend it past a certain point because something inside the knee is blocking it. Catching is a milder form of the same problem, where you can get to the point that the motion stops, but you can twist or rotate your knee past that point.

Buckling or giving way

Having the tibia (shin bone) shift out from under the femur (thigh bone) usually represents an ACL injury. If your knee buckled during the traumatic injury and keeps happening in the days after the injury, you risk doing more damage to the other structures inside the knee.

This list is not comprehensive, so if you are concerned about your knee injury or knee pain, it never hurts to see your doctor or an orthopedic surgeon.

Also read:
Should I see a doctor for a knee injury?
What type of doctor should I see for my knee injury?

Please remember, while I appreciate your questions, I cannot and will not offer specific medical advice by email, online, on my show, or in the comments at the end of these posts. My responses are meant to provide general medical information and education. Please consult your physician or health care provider for your specific medical concerns.

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