Gratiot County Herald

Transforming patient information into patient understanding.

The kneecap (patella) has a very predictable place right in the center of the knee.
It lies in a groove on the front of the thigh bone (femur).

What Use Is It?

Good question. Well for one it is a protection for the front of the knee. It is a fairly thick bony structure. It gives the thigh muscles (quadriceps) leverage in their job of straightening the knee which is extremely important.

Normally the kneecap slides up and down slightly as your knee bends and straightens.

Dislocation

If the kneecap slides too far to one side or the other instead of going straight up and down, the kneecap can dislocate.

Dislocation can happen after a fall or a sharp blow to the side of the knee. The kneecap can partially or completely dislocate.

Causes

Dislocation is more likely to happen when

• the groove the kneecap fits in is too shallow

• if the person is slightly knock kneed

• if weakness exists in the quadriceps

• if the kneecap had dislocated before

Symptoms

The degree of symptoms depends on how far out of place the kneecap slips and how much trauma occurred when it happened.

Partial. If the slip is only partial and the patella goes back into place by itself you are lucky. You have probably saved a trip to the ER. You definitely will have acute pain, swelling and stiffness that is worse when you move around.
Complete. The knee will buckle and be unable to support weight. You will hear a pop when the patella dislocates and the knee looks deformed. ER, here we come!

Treatment

Partial dislocations (subluxation) need to be thoroughly evaluated by examination and x-ray, but I usually can do this in the office at an early time. A special knee brace and a rehab program follow if there is no other damage.

Complete dislocations of the patella need careful exam and x-rays followed by sedation/pain medication and gentle pressure to put it back in place. This is followed by immobilization, then a knee brace and rehab by a physical therapist. If the thigh muscles are strong, they are better able to hold the kneecap in its correct position.

What Else?

I wish it were always that simple as I have outlined above. Depending on several factors including the amount of tissue damage at dislocation, the patella may remain loose and unstable. It can have a tendency to continue to partially or even completely “slip out”.

If that happens, I often need to do arthroscopic or even open surgery to keep the kneecap in place.

I hope this sheds some light on a fairly common problem I deal with.

Gratiot County Herald Archive and Office Website

The new all redesigned website also has the Archive of all previous articles I have written for Gratiot County Herald.

Please check out the website www.orthopodsurgeon.com for a great collection of articles about all the things I treat in the office and hospital.

Our goal is simple – To help people return to more pain free, functional lives. I specialize in you.

Good health. Good life. All the best to you.

Be well.

Dr. Haverbush