What are the 2 causes for a patella dislocation?

A patella dislocation occurs when the knee cap pops sideways out of its vertical groove at the knee joint. It’s usually caused by force, from a collision, a fall or a bad step.

What is the most common patellar dislocation?

Lateral – The most common type of patellar dislocation. Horizontal – A rare occurrence, in which the patella has rotated on its horizontal axis with the articular surfaces facing either proximally or distally.

What is the difference between a patellar dislocation and subluxation?

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.

What is the mechanism for a dislocated patella?

Acute patellar dislocations typically occur as a result of trauma, usually a non-contact twisting injury to the knee, or from a direct blow to the medial aspect of the knee. A common mechanism is external tibial rotation with the foot fixed on the ground.

How is patella dislocation treated?

A dislocated kneecap will be quickly put back into position (referred to as “reduction”) by the consultant. This may need to be performed under local or general anaesthetic. Once the kneecap has been put back into place, you will need to rest the knee and use ice, compression and elevation to control swelling.

How is a dislocated patella treated?

Is patella dislocation common?

Patellar Dislocations: Signs, Symptoms, Treatments. Patellar dislocation is a common and often painful injury. The patella bone connects the muscles of the thigh to the front of the tibia, or lower leg.

How long does it take to heal from a patella dislocation?

A dislocated kneecap is a common injury that normally takes about 6 weeks to heal. It’s often caused by a blow or a sudden change in direction when the leg is planted on the ground, such as during sports or dancing. The kneecap (patella) normally sits over the front of the knee.

How serious is a dislocated patella?

A dislocated kneecap is not usually serious and will often pop back into place by itself. But it’s still a good idea to get it checked by a health professional: if your kneecap has gone back into place by itself – go to your nearest urgent treatment centre or A&E.

What is the glide test for patella dislocation?

Patella apprehension test of Fairbank or Apley : displacement of the patella laterally in slight flexion causes pain and expectation of pending dislocation Patellar shift (glide) test : knee flexed 20° to 30°; 1 quadrant or less medial glide is indicative of tight lateral Patellar tilt test : evaluates tension of the lateral restraint

What causes a dislocation of the patella?

Pathology. Patella dislocation most commonly results from a twisting motion, with the knee in flexion and the femur rotating internally on a fixed foot (valgus-flexion-external rotation) 1.

Why does the patella have a large Q angle?

A large Q angle has been linked to increased internal rotation of the femur. An increase in Q angle could occur due to deficiencies above and/or below the patella. Weakness of the hip external rotators (gluteus maximus and posterior gluteus medius(PGM)) leads to increased internal rotation.

How to diagnose lateral patellar retinaculum dislocation?

The presence of an abnormal medial patellar retinaculum should suggest the diagnosis of transient lateral patellar dislocation 1. The images should be scrutinized for the presence of chondral or osteochondral injury, especially if displaced as an intra-articular body, as this may affect surgical management.