What causes your knee to lock up? Hint: It’s not the meniscus

I hear it everyday - someone comes in after getting meniscus surgery because their knee was locking up and they still have pain. Patients with locked knee usually notice their knee locks up when going from sitting to standing or for no reason at all. The theory goes that a piece of a torn meniscus gets in the way and doesn’t let your knee unlock. But here’s the thing, there isn’t much scientific evidence that this meniscus surgery is necessary. What if I told you there was a key muscle in the back of your knee that unlocks it and most doctors completely forget about it and just go straight to surgery.

I hear it everyday – someone comes in after getting meniscus surgery because their knee was locking up and they still have pain. Patients with locked knee usually notice their knee locks up when going from sitting to standing or for no reason at all. The theory goes that a piece of a torn meniscus gets in the way and doesn’t let your knee unlock. But here’s the thing, there isn’t much scientific evidence that this meniscus surgery is necessary. What if I told you there was a key muscle in the back of your knee that unlocks it and most doctors completely forget about it and just go straight to surgery.

The real cause: The Popliteus Muscle

What if the cause of your knee locking up and the eventual meniscus tear was a tight muscle that most doctors don’t know about or just ignore? Let me explain. The Popliteus muscle is one of those muscles that you’ve likely never heard of before. It’s the key that pulls the lateral meniscus out of the way and unlocked your knee.

it pulls the lateral meniscus back and out of the way so that the meniscus isn’t crushed between the tibia and femur bones as the knee flexes. So if this important muscle that keeps the lateral meniscus out of harms way wasn’t working properly, your lateral meniscus would be crushed (and your knee would feel like it was locking).

Surgeons cut out everything but the cause

If your lateral meniscus is getting crushed 100’s of times because your popliteus isn’t pulling it out of the way, your lateral meniscus would get a tear, that you can see on MRI. In our modern medical system, your trained to go to an orthopedic surgeon to get an MRI when you have pain. A knee meniscus tear on MRI usually leads to surgery for the tear. The thing is in meniscus tear surgery nothing is repaired, the surgeon cuts out of the piece of meniscus getting in the way. Operating on a lateral meniscus tear caused by a dysfunctional Popliteus muscle makes no common sense. The focus should be on the cause (the Popliteus muscle) and not the effect (the meniscus tear).

A simple test

The next time your knee locks up, look at the picture and massage the back of your knee hard in the popliteus area for a few minutes. If it helps the locking then cutting part of your meniscus out is a terrible idea.

What causes your popliteus to become dysfunctional

If you have an irritated nerve coming from your low back then it could cause your popliteus to develop trigger points and not work correctly. Or if you have ever sprained an ankle that was never properly treated, or have hip pain, then your gait could be altered causing your popliteus muscle to lock up.

The Good News

If your locked knee is caused by muscle issue, then it makes sense to treat the muscle causing the problem and not cut out a perfectly good meniscus. At my clinic in Tampa, FL I use dry needling, electro-acupuncture and perineural injections to treat the nerves and muscles causing your pain.

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