Kneecap Dislocation

[tdarko]

hoterdoc,

I know exactly where the patella is. Maybe the OP doesn't understand what is exactly going on. The action that happens when you extend and flex your leg is called the "Screw Home Movement" and this is where in the last few degrees of extension, the small degree of rotation that occurs between the tibia and femur that "locks" the knee joint in place are rotationally screwed together (screwed home). When beginning flexion from full extension, the knee joint "unscrews" and the rotation is reversed.

Your patella ALWAYS essentially locks and unlocks itself. The only part of the knee that locks from injury is the meniscus. When you tear your cruciate or your collateral ligaments the exact opposite of "locking" happens, your leg is loose because those ligaments are there for stability in internal/external rotation, flexion, and extension--w/o one of these ligaments all of the sudden your leg hasn't any stability.

Everything he said adds up to a bucket handle tear.

1) His knee locks up
2) Bucket handle tears are the most common tears in the knee that are overlooked and the patient is sent home
3) It hurts when his knee locks up, not during daily living.

He also said it happens when his knee is in a semi-bent position, this is exactly when the meniscus rolls up and gets trapped in the intercondylar notch.

Please understand that everything he has said in this thread makes it seem that it is almost certainly what I said it is.

[Drew16]

[ QUOTE ]
hoterdoc,

I know exactly where the patella is. Maybe the OP doesn't understand what is exactly going on. The action that happens when you extend and flex your leg is called the "Screw Home Movement" and this is where in the last few degrees of extension, the small degree of rotation that occurs between the tibia and femur that "locks" the knee joint in place are rotationally screwed together (screwed home). When beginning flexion from full extension, the knee joint "unscrews" and the rotation is reversed.

Your patella ALWAYS essentially locks and unlocks itself. The only part of the knee that locks from injury is the meniscus. When you tear your cruciate or your collateral ligaments the exact opposite of "locking" happens, your leg is loose because those ligaments are there for stability in internal/external rotation, flexion, and extension--w/o one of these ligaments all of the sudden your leg hasn't any stability.

Everything he said adds up to a bucket handle tear.

1) His knee locks up
2) Bucket handle tears are the most common tears in the knee that are overlooked and the patient is sent home
3) It hurts when his knee locks up, not during daily living.

He also said it happens when his knee is in a semi-bent position, this is exactly when the meniscus rolls up and gets trapped in the intercondylar notch.

Please understand that everything he has said in this thread makes it seem that it is almost certainly what I said it is.

[/ QUOTE ]

this sounds exactly right. The first time did happen when I was young and wearing cleats. I grew up playing baseball and soccer.

Is this something worth seeing a specialist over if they are hard to detect, and no particular cure?

[hobbes9324]

Thanks for the correction...thats what I get for not looking things up that I think I remember....

MM MD

[tdarko]

[ QUOTE ]
this sounds exactly right. The first time did happen when I was young and wearing cleats. I grew up playing baseball and soccer.

Is this something worth seeing a specialist over if they are hard to detect, and no particular cure?

[/ QUOTE ]

This all depends on you. How bad is it? Can you live with it? If it is a problem I would see a specialist, especially since they will now have an idea of what to look for. The reason it is hard to detect is b/c they aren't looking for it and "cure" is the probably the wrong word since it is something you fix.

Good luck with this either way.

[Drew16]

Ive lived with it for 17 years. It hurts like hell when it happens but it doesnt happen everyday. The only real problem is I find myself being careful how I twist and bend my knees and when I play sports I try to go easy on my knee.

Im just worried if it "pops" out 10, 15, 20 more times its gonna ruin my knee and cripple me with arthritis.

[Jeff W]

Do squats with perfect form--no lateral movement of the knees. Eventually you'll rectify the problem by strengthening the muscles that keep the kneecap in place.

[cbloom]

Wow, we have a lot of docs lurking. There should be an "Official Ask Dr. OOT" where we can get medical advice.

[hoterdoc]

o.k.,
I admit I could be wrong, and may indeed be a meniscal injury,

I presumed the OP was correct, when he self diagnosed a 'kneecap' dislocation. After 9.5 years of Emergency Medicine, I well know the dangers of ASSuming anything. ( no offense intended)


to settle it, a picture is worth a thousand words, as they say . . .

when it happens, does it look like THIS???

[hoterdoc]

in exchange for some coaching?

[tdarko]

[ QUOTE ]
o.k.,
I admit I could be wrong, and may indeed be a meniscal injury,

I presumed the OP was correct, when he self diagnosed a 'kneecap' dislocation. After 9.5 years of Emergency Medicine, I well know the dangers of ASSuming anything. ( no offense intended)


to settle it, a picture is worth a thousand words, as they say . . .

when it happens, does it look like THIS??

[/ QUOTE ]

Oh, I sure do understand that bolded part and you are completely right and it is why I realize you could be right and I may very well be wrong. This is also why he should probably see a specialist and not have this diagnosed blindly over the internet.

The reason it sounded meniscal was b/c of the locking and pain only during this locking.

The picture you showed me was just a subluxed kneecap right?

Like you said, I could be wrong but a dislocated knee cap will be very tender, swell, and he will have constant pain. I had thought he said it didn't hurt until his leg was in a certain position and then it "catches" and "locks."

He hasn't said anything in this thread that would lead me to think otherwise, even from your picture...but like you said nobody is every a 100% right--so uh thanks for pointing that out.