What are the signs and symptoms of patellar dislocation?

Symptoms of kneecap dislocation include:

  • Knee appears to be deformed.
  • Knee is bent and cannot be straightened out.
  • Kneecap (patella) dislocates to the outside of the knee.
  • Knee pain and tenderness.
  • Knee swelling.
  • “Sloppy” kneecap — you can move the kneecap too much from right to left (hypermobile patella)

How do you check for patellar dislocation?

To diagnose a patellar subluxation, your doctor will bend and straighten the injured knee and feel the area around the kneecap. X-rays may be used to see how the kneecap fits into the groove at the bottom of the patella and to identify any other possible bone injuries.

What is crossing sign in knee?

The crossing sign is seen on true lateral plain radiographs of the knee when the line of the trochlear groove crosses the anterior border of one of the condyle trochlea. It is a predictor of trochlear dysplasia. Trochlear dysplasia has been linked to recurrent patellar dislocation 1,2,4.

What is the special test for a dislocated patella?

The best test to determine whether a patient is having symptoms from a subluxing or dislocating patella, is the lateral patellar apprehension test. It is performed with the knee flexed to 45° over the side of the examining table.

Can you bend a dislocated knee?

You won’t be able to move the knee or bear weight on it for a few weeks during the healing process. After the pain and swelling has gone down, your doctor may reassess the knee to determine if it needs reconstruction surgery to repair damaged tendons, ligaments and other soft tissues.

How does a dislocated knee feel?

When you dislocate your knee, you may hear a popping sound. Common symptoms include: It hurts a lot. Your knee is in so much pain that you can’t move or straighten it.

Can you dislocate your knee without tearing ligaments?

Causes. Patellar dislocations can occur either in contact or non-contact situations. An athlete can dislocate his/her patella when the foot is planted and a rapid change of direction or twisting occurs. Usually a pre-existence ligamentous laxity is required to allow a dislocation to occur in this manner.

What is a patella alta?

Patella alta or high-riding patella refers to an abnormally high patella in relation to the femur. The patella sits high on the femur where the groove is very shallow. Here, the sides of the femoral groove provide only a small barrier to keep the high-riding patella in place.

What is Patella Alta and Baja?

If the patella is sitting too high (equivalent to the patellar tendon being too long) then this is called patella alta. If the patella is sitting too low (i.e. a short patellar tendon) then this is patella baja (sometimes referred to as patella infera).

What is the difference between patellar subluxation and dislocation?

In a patellar dislocation, the patella gets pushed completely out of the groove. The other type of instability is known as chronic patellar instability. In this type, the kneecap usually only slides partly out of the groove. This is known as a subluxation.