Hyperextension of the knee, also known as “genu recurvatum” occurs when the leg excessively straightens at the knee joint, putting stress on the knee structures and the back of the knee joint. Anybody can develop a hyperextended knee, but it is more common among athletes, especially those involved in contact sports such as football, lacrosse, skiing and soccer. The condition occurs when the knee suffers a strong blow, or when there is a quick deceleration or stop. There has been research that shows that the condition is more common in female athletes more than their male counterparts.
The knee joint is forced to bend in the wrong way, during hyperextension of the knee; this brings about tissue damage and a lot of pain and swelling. In some severe cases, the popliteal ligament (found at the back of the knee), the posterior Cruciate Ligament (PCL) and the Anterior Cruciate Ligament (ACL) are sprained or damaged.
The first symptom is instability of the knee – There will be a lot of instability in the knee joint, and patients will say that their legs are giving out when walking, making it difficult to stand on one leg or even take a walk.
Pain – There will be a lot of localized pain in the knee immediately after hyperextension. The pain varies from mild to severe; if there is more damage to the ligaments, then the pain will be stronger. The pain can be felt as a sharp pain at the back of the knee or it may feel like a pinch from the front of the knee.
Decreased Mobility – When a patient has a hyperextended knee, they have difficulty bending or straightening the leg. There will be a lot of swelling around the knee and this will affect the limits that you can move the leg. Others injuries to the three ligaments mentioned and the meniscus will also affect how much the leg can be moved.
Bruising and swelling – as is expected from this kind of physical injury, there will be immediate or delayed swelling and bruising of the knee and its surroundings. This can be serious or mild depending on the extent of the damage to the knee.
Causes of hyperextended knee
A hyperextended knee occurs when the knee is forced to go beyond the natural range of motion, due to high stress placed on the knee ligaments. This injury occurs in the anterior and posterior cruciate ligaments. This high kind of stress on the knee joint and its ligaments is usually brought about by sports and accidents.
Sports such as lacrosse and football are the main causes of this injury, but sometimes running for long distances ca also bring about the injury. This is why technique is very important for long distance runners. Some other times this injury can be caused by an athlete getting on one leg and placing all body weight on it. This is common in basketball as the player makes a shot.
When playing sports such as rugby and football, the power of being tackled at the knees can puch the femur in such a way that it goes over the patella, and this will also put pressure on the knee ligaments and cause the hyperextended knee.
Car accidents are said to bring about the most severe forms of hyperextended knee. There is a lot of force generated during a car accident, and these can bring about damage to the knee ligaments and surrounding tissue bringing the problem up.
Treatment of hyperextended knee
All soft tissue damage is best treated by using the RICE methods; the same is advised for a patient with a hyperextended knee
You should cease the activity that caused the injury and see you doctor immediately. You should avoid all forms of contact sports, high-impact activities or high-intensity motions. You should adopt exercises that have a gentle motion range for the knee. You should also use anti-inflammatory medication to reduce the pain and swelling.
You should use ice on the knee for 15-minute intervals several times a day. Ice is great for reducing pain and swelling. You should put the ice in a towel to prevent irritation of the skin by the ice.
You should use a compressions wrap or elastic bandage to help reduce the swelling and pain on the knee joint.
The leg should be placed in an elevated position as much as possible.
Knee hyperextension can sometimes result in the rupture or tear of a tendon, especially the ACL. In this case, surgery will be required to repair the damaged tendon. It is also possible for the PCL or Poplitieal tendons to rupture, but the ACL is the most common. Similarly, there may be damage to some of the structures around the knee such as the meniscus or the bones adjacent to the knee injury. This is another case where surgery will be required for the structures to be repaired and set.