A Simple Guide to Knee cap Dislocation

A Simple Guide to Knee cap Dislocation
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What is Knee cap Dislocation?
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Knee cap Dislocation is when the knee cap (patella) moves or slides out of place. This usually occurs on the outer side of the knee.


What are the causes of Knee cap Dislocation?
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1.Dislocated knee caps most often occur in people with loose joint ligaments.

It can occur due to sudden strain on the knee ligaments causing the kneecap to protrude out of its loose ligaments.

2.Dislocation of the knee cap may also occur due to trauma.

A sudden blow to the medial part of the knee can cause the knee cap to dislocate laterally.

3.People who are prone to dislocated knee caps usually have loose ligaments with hyperflexion of the wrists or flat feet.

This condition is usually inherited and are more common in women than in men.


What are the symptoms and signs of Knee cap Dislocation?
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Symptoms:

1.Knee cap is displaced to the lateral position

2.knee swelling and effusion due to displacement of the knee cap.

3.Knee pain and tenderness is present.

4.The knee is usually held in slight flexion.

5.There is difficulty in lifting the leg

6. Patient usually walks with a limp.

Signs:

1.Tenderness and swelling of the knee

2.Knee cap is displaced to the outside or lateral part of the knee

3.In most cases the knee cap may have returned to the central position of the knee but there is still tenderness and swelling.

4.The knee cap can move excessively from right to left.(hypermobile)

How to investigate the cause of Knee cap Dislocation?
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1.examination of the knee would confirm presence of the dislocated knee cap.

There is lateral displacement of the knee cap and swelling of the knee.
Movement of the knee may be painful.

2.A knee x-ray should be done to exclude any fracture especially in the case of injury or in the elderly.

A skyline view of the knee should show the shift of the patella laterally.

3.MRI of the knee can be done to see any damage in the cartilage or meniscus of the knee.


What is the Treatment of Knee cap Dislocation?
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Conservative treatment:
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1. Most cases of knee dislocation can treated by simple reduction of the dislocated knee cap.

The heel of the leg is lifted to extend the knee and flex the hip thus relaxing the quadriceps muscles(front muscles of the thigh)

Gentle pressure is exerted on the knee cap to place it to its normal position.

The knee is then immobilized for 2-3 weeks.

Quadriceps exercises are begun as soon as possible to build back your muscle strength and improve the knee's range of motion.

Drug Therapy:
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1.Pain killers such as NSAID(non-steroidal anti-inflammatory drugs) for pain

2.Muscle relaxant to relax muscles

Surgery:
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Surgery is required if:

1.the knee remains unstable

2.Injury of the knee cap cause a partial rupture of the medial retinaculum and supporting ligaments of the knee cap.
This can cause recurrent episodes of subluxation or dislocation of knee cap.

Surgery is done to stabilize the knee cap.
Reconstruction of the quadriceps extensor muscles is done to tighten the ligaments surrounding the knee cap.


What is the prognosis of Knee cap Dislocation?
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Prognosis using conservative methods is fair.

Recurrences are quite common.

Preventative measures such as knee guard, quadriceps exercises, avoidance of sudden turns and twisting of the knee may help.

Prognosis after surgery is usually good as there is tightening of the knee cap ligaments and the quadriceps muscles.


What is the Prevention of Knee cap Dislocation?
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1.proper technique when exercising.

2.Maintain strength and flexibility of the knee by exercising the quadriceps muscles.

3.Wearing a knee guard