patellar dislocation

Quick Overview

• What to do with a patellar luxation? Soothe those affected, restrain leg, possibly cool, bring to the doctor or call ambulance
• Patellaluxation risks: Violation of surrounding structures (such as ligaments, bones); painful bruising in the joint; Inability to move the lower leg
• When to the doctor? In principle, any patellar luxation should be evaluated and treated by a physician.

Attention!

• Never try to repair a cracked kneecap yourself. It would probably worsen the injury.
• Never place ice cubes or coolpacks directly on the skin to cool the knee, but always with at least one layer of fabric in between. Otherwise threaten local frostbite.
• If the articular cartilage is damaged during the patellar dislocation, this can lead to premature joint wear (arthrosis).
• Even with optimal treatment, renewed patellar luxations are not excluded. This is especially true if the operation was late.

Patellar Luxation: What to do?

A patellar dislocation is very painful – and often a shock to the person affected: If your own patella suddenly protrudes sideways out of your leg as a knobby, it can be very frightening. It is all the more important that you, as a first responder, act courageously when someone has knocked out the kneecap. What you should do is this:

• Reassure the person concerned and explain to him everything you do. That creates trust.
• Remove tight-fitting clothing in the wrist area (trousers). In the case of a dislocation, the area around the joint usually swells considerably.
• Relieve the knee, that is: put the affected person down, if he does not already sit. Often people with a dislocation instinctively take a restraint in which the pain subsides somewhat. Do not force the affected person to another position.
• Very important: Do not move your knee! Otherwise you could damage the surrounding ligaments, muscles and nerves!
• If possible, cool the swollen area (for example with Coolpack). This can relieve bruising, swelling and pain.
• Bring the victim to the doctor as soon as possible or call an ambulance. This also applies if the kneecap has slipped back into the joint by itself.

Patellar luxation: risks

If the kneecap has jumped out, usually forms a bruise in the joint quickly. This increases the pressure within the joint, which increases the pain.

Occasionally, in the course of a patellar dislocation, smaller pieces of bone may break off the patella or femur. The bone fragments then float loose in the joint. The straps around the kneecap can tear.

Patellar Luxation: When to the doctor?

If the kneecap has jumped out, it should be retracted as soon as possible by a doctor. Even if she has regained herself by herself, a doctor is needed: he can check whether surrounding structures have been damaged in the dislocation.

Patellar luxation: examinations at the doctor

The doctor usually recognizes at first glance whether the kneecap has jumped out. Sometimes, as soon as the doctor examines the patient, she has already slipped back to her original position by herself (“spontaneous reduction”). The doctor can then conclude that the patient is patellar on the basis of the information provided by the patient.

Physical examination

Using certain examinations, the doctor checks whether the knee joint is actually dislocated. An example is the so-called apprehension test. The doctor exerts lateral pressure on the patella to the outside. If the patient shows a defensive posture or if the thigh muscle (quadriceps) reacts more frequently, this is a sign of a dislocation.

Imaging procedures

They help to examine the patellar joint and its surrounding structures for possible accompanying injuries. First and foremost, an X-ray examination is used. In some cases magnetic resonance imaging (magnetic resonance imaging, MRI) or articulation (arthroscopy) is also necessary.

Arthrocentesis

If an effusion in the joint, a puncture may be useful. The doctor removes effusion fluid with a hollow needle. This relieves the joint and at the same time makes it possible to analyze the fluid more precisely. When she is bloody, this often indicates torn straps. In addition, if there are still grease eyes in the effusion fluid, a bone in the area of ​​the patellar joint is probably also fractured (fracture).

Patellar dislocation: treatment by the doctor

In the case of patellar dislocation, manual reduction (reduction) is usually sufficient as therapy when the kneecap has come out for the first time and by force (traumatic patellar dislocation). The doctor slowly stretches the leg in the knee and carefully guides the patella into its correct position. Previously, he can give the patient a painkiller and sedative.

As soon as the patella is back in place, the patient usually gets a special brace (orthosis) for three to four weeks. This stabilizes the leg in the extended position. This rail can fully load the leg.

Surgical procedure for patellar luxation

If the doctor fails to retract the knee joint manually and / or if there are concomitant injuries, surgery is necessary. The same applies if the kneecap has jumped out again. Because the more frequently a joint dislocates, the more unstable the support structures become. During surgery, the surgeon can tighten and stabilize the joint.

Finally, there are over 100 different surgical techniques for treating patellar dislocation. They all aim to reduce the pull on the kneecap to the outer side of the knee and thereby reduce the risk of dislocation. For a number of procedures today, a so-called arthroscopic procedure is sufficient. The knee is operated through small accesses in the tissue (keyhole technique). The best results can be achieved by a combination of different surgical procedures.

In young, athletic people with patellar dislocation, doctors operate more often than in older patients.

Prevent patellar luxation

The most effective measure to prevent a patellar dislocation is targeted training for the musculature that stabilizes the knee. This is especially important if someone has risk factors for such a dislocation. Such risk factors are:

• Patellar dislocation in the prehistory: If ever a patella has jumped out, the probability of a new dislocation is increased. Because every dislocation and the associated stretching or injury of surrounding structures makes the joint more unstable.
• Female gender: Patellar luxation is especially common in adolescent, slim athletes.
• X-Legs: Axial misalignment increases lateral pull on the patella than normal. This favors a dislocation.
• congenital malformations of the patella or the patella sliding bearing
• congenital or accidental elevation of the kneecap
• Weakness or imbalance of the extensor muscles on the thigh
• Systemic diseases with connective tissue weakness: For example, the hereditary diseases Marfan syndrome and Ehlers-Danlos syndrome promote patellar dislocation.