Kneecap Dislocation Symptoms

A kneecap dislocation causes significant pain and deformity of the knee joint.

The kneecap almost always dislocates to the outside of the joint.

Pain and swelling are common symptoms of kneecap dislocation.

Woman getting a knee exam

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Over time, bruising may also develop around and below the knee joint.

Kneecap dislocation occurs with the kneecap dislodges from its groove on the thigh bone.

Sometimes people use the words knee dislocation to describe a kneecap dislocation; this is incorrect.

A subluxation implies that the kneecap shifting, but not coming completely out of place.

The most important torn structure is called the medial patellofemoral ligament, or MPFL.

This ligament secures the patella to the inside (medial) part of the knee.

When a kneecap dislocation occurs, the MPFL can be torn or stretched.

That is why recurrent dislocations of the kneecap can continue to occur in some patients who have this injury.

Therefore, anesthesia (either local or general) may be administered to help reposition the kneecap.

Most kneecap dislocations can be repositioned by simply straightening the knee once control of the pain and spasm allows.

After repositioning the kneecap, treatment usually begins with R.I.C.E.

treatment (rest, ice, compression, elevation) to control pain and help with swelling.

Crutches and a knee brace are usually offered to help control pain.

Once the acute swelling has subsided, treatment may progress.

The next phase of treatment usually consists ofphysical therapyand bracing the kneecap.

As discussed earlier, kneecap dislocations can become a recurrent problem.

In patients who have recurrent (repeat) dislocations, there aresurgical options.

In some circumstances, a realignment of the extremity, involving cutting and repositioning bone, may be recommended.

Surgery After First Dislocation?

Recent interest has developed in preventing these recurrent dislocations.

Some surgeons are trying to restore the normal anatomy by repairing the MPFL after a first-time dislocation.

Surgery after the first dislocation is controversial because not all patients who dislocate their kneecap will have another dislocation.

In addition, early surgery has not been shown through scientific study to be helpful in preventing arthritis.

Just remember: there is not always a right and a wrong answer.

It never hurts to seek out some other advice.

That said, it is also important to remember that too much advice can clutter thinking.

Respizzi S, Cavallin R.First patellar dislocation: from conservative treatment to return to sport.Joints.

2015;4(3):e29301.

doi:10.5812/atr.29301

Mohseni M, Simon LV.Knee dislocation.

John Hopkins Medicine.Patellar instability.

2011;(11):CD008106.

A systematic review of overlapping meta-analyses.Arthroscopy.

2015;31(6):1207-15. doi:10.1016/j.arthro.2014.11.040