Patella Dislocation: A Real Pain In The Knee

Patella dislocations are a painful injury to endure. Making sure you rehabilitate them well, will help you to keep moving and living your life.

The knee joint is composed of the thigh bone (femur) and leg bone (tibia) and a small floating bone at the front, commonly known as the kneecap (patella). The interaction between these bones allows for smooth movement of the knee as it bends and straightens.

During movement, the kneecap sits in a groove at the front of the knee and acts as a mechanical see-saw. This protects the knee joint and improves the efficiency of the muscles working to move it. When the patella moves out of this groove and back in, it is called a subluxation. If the patella moves and stays out of this groove it becomes a dislocation.

What are the symptoms of a patella dislocation?

The first time the patella dislocates is usually the most traumatic and painful. The knee may give way, and a visible lump can be noticed where the patella has dislocated. There will often be bruising, swelling and the knee may feel unstable. First time dislocations may also cause a hemarthrosis or bleeding within the knee joint. If there is damage to the ligaments of the knee, subsequent dislocations can happen more easily, and from everyday activities, causing the knee to give way suddenly.

What are the causes?

First time patella dislocations often occur due to a traumatic event. The most common cause of patellar dislocation is a non-contact injury to the knee with a twist of the leg (the thigh bone rotates internally on a fixed leg and foot). In addition, a direct blow to the side of the knee can also dislocate the patella.

If there is some instability of the joint, dislocations can occur more regularly and from smaller forces. Dislocations usually occur when the knee is bent and the kneecap slips back into place when the knee is straightened again. While the kneecap can be dislocated in both directions, it usually dislocates towards the outside of the knee.

Certain factors can make dislocation more likely, including overall hyper-flexibility, damage to the ligaments of the knee and muscular imbalance of the quadriceps. The structure and angle of the knee joint itself can also make dislocation more likely. This can be seen in the increased prevalence of dislocations for women as they have a slightly different angle of femur compared to the tibia than men. A traumatic dislocation can cause instability that can lead to future dislocations.

How can physiotherapy help?

An acute patella dislocation should be treated like any traumatic injury and assessed by a medical professional to reduce pain and swelling, make an accurate diagnosis and check for fractures. While the kneecap may relocate itself quickly, ensuring that it is able to heal correctly to prevent further dislocations may require immobilization for up to six weeks.

Our physiotherapists will be able to identify any factors that may predispose you to further dislocations and provide you with a personalized treatment program. Once your initial pain has been settled, a strengthening program will be the main stay of your rehabilitation. Strengthening exercises for your core, gluteals, quads and hamstrings will be used. Balance and proprioception (your sense of where your body is in space) are often reduced following an injury. Specific exercises that help increase your balance/proprioception will be used to help regain control of your knee. Your therapist may provide you with education and advice regarding bracing or taping.

In severe cases of instability, surgery may be recommended to stabilize the knee however this is usually not considered unless there has been a fracture or until a full rehabilitation with physiotherapy has been completed.

If you or someone you know have suffered from a patella dislocation, get in touch with the team at Cairnhill Physiotherapy to start your road to recovery and getting back to what you love doing.