Patellar Instability

Patellar Instability

 What exactly is patellar instability?

Tendons connect the patella (kneecap) to the femur (thigh bone) and tibia (shin bone). The patella glides up and down in a groove at the end of the femur (trochlear groove) as the knee bends and straightens. When the kneecap travels outside of this groove, it causes patellar instability.

Patellar instability is classified into two categories. The first type is referred to as a traumatic patellar dislocation. This is most typically the result of a knee injury. The patella is moved fully out of the groove in a patellar dislocation. Chronic patellar instability is the other type of instability. In this case, the kneecap normally only partially moves out of the groove. This is referred to as a subluxation.

What are the symptoms and indicators of patellar instability?

Pain, swelling, stiffness, trouble walking on the affected leg, and/or buckling, catching, or locking sensation in the knee are all possible symptoms. Finally, there may be a visible deformity in the affected knee.

The majority of patients report that their kneecap has shifted or migrated out of place. Usually, the kneecap will return on its own, but in other cases, it will need to be replaced in the emergency room.

Pain from persistent patellar subluxations may be less severe than pain from a catastrophic injury.

Patients may complain of soreness beneath the kneecap, particularly during activities that require deep knee bending.

Patellar Instability Diagnosis

Your provider will most likely make the diagnosis after collecting a medical history and completing a physical exam. X-rays will most certainly be taken, however they may be unnecessary if the kneecap has already returned to its natural position. An MRI may also be required to assess any cartilage damage induced by a severe patellar dislocation. An MRI, on the other hand, is usually not indicated until your knee has had a chance to heal.

Treatment for Patellar Instability

If the kneecap does not return to its original position (reduction) on its own, quick medical treatment is required to reduce the patella. Initial dislocations are usually treated non-surgically with rest, a knee brace, and crutches. Physical Therapy is usually started after a period of rest to strengthen the muscles in the knee that assist maintain the kneecap from sliding out of the groove.

In some cases, surgical intervention may be necessary. There may be cartilage that is knocked loose and sits in the knee during bouts of acute patellar dislocation. This is known as a loose body, and it must be removed.

If a ligament in the knee, such as the medial patellofemoral ligament, ruptures, reconstruction of the ligament may be indicated.

If your child continues to have repeated patellar dislocations (the kneecap comes out of the groove despite non-operative treatment), he or she may be a candidate for a surgical surgery to realign the kneecap and place the patella in a better position. One of these procedures is an arthroscopic procedure. Another “open” operation is an osteotomy, which involves cutting and repositioning the bone to improve patellar tracking (the way the patella moves when you bend and straighten your knee).

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source : hopkinsmedicine