My knee gets stuck and I have to wiggle it to straighten it. What is happening?

What the wiggle is actually doing

A torn meniscus can leave a loose tongue or flap of tissue still attached at one end. When you bend the knee, that flap can slide between the thigh bone and shin bone, where it acts like a wedge in a door. Twisting or shaking the leg changes the angle of the joint and lets the flap slip back to where it belongs, often with a felt or audible clunk.

Other causes of the same sensation include a loose fragment of bone or cartilage floating in the joint, and less often an irritated plica or a kneecap problem.

Why it should not be ignored

Each time the flap is trapped and pulled free, it can extend the tear and rub the cartilage that covers the bones. A tear that starts small and repairable can become larger and more complex. In some cases a bucket-handle tear develops, where a large piece of meniscus flips over and the knee locks completely.

This is different from a painless click when you bend, which is very common and usually harmless.

What to do until you are seen

• Avoid deep squatting, sitting on your heels and pivoting on that leg
• Get up from low seats slowly and straighten the knee before turning
• If it jams, sit down, relax the thigh, and gently bend and straighten it rather than forcing it
• Avoid football, padel and running until it has been assessed

Assessment at Aman Hospital

Dr. Gelber will ask exactly when the knee sticks and how it frees, then examine the joint line and rotation. An MRI usually shows the flap or a loose body and helps plan treatment. Repeated catching from a displaced flap is one of the clearer reasons for arthroscopy, during which the flap is repaired if the tissue allows, or trimmed back to a stable edge.