Knee hyperextension refers to the injury that occurs when the leg straightens excessively at the knee joint, stressing the knee structures and the rear of the joint. Although this injury can in general happen to anyone, in practice it most often happens to athletes in certain sports. It is usually the result of a direct blow to the knee or of the forces exerted on the joint when the athlete is forced to stop or decelerate abruptly. These events tend to happen frequently in sports like football, lacrosse, skiing or soccer, which makes athletes in those sports especially vulnerable. The typical symptom of a knee hyperextension include pain and swelling at the knee joint. If the injury is severe, it may be accompanied by a knee sprain due to over stretched ligaments or even by an ACL or PCL tear. The popliteal ligament (that runs along the back of the knee) may also suffer damage during knee hyperextension.
Symptoms Of Knee Hyperextension
Typical symptoms of knee hyperextension can include the following:
Knee instability or a “giving away” feeling in the knee as though it is unable to bear the body’s weight. Standing on one leg may become difficult or impossible;
Pain at the back of the knee. This can range from a mild ache to a sharp pain depending on whether there is ligament damage;
In addition to pain at the back of the knee, a patient with a knee hyperextension may also feel a pinching pain at the front of the knee;
Difficulty bending the knee;
Swelling and bruising around the knee.
Treatment Of Knee Hyperextension
Conservative treatment of this injury usually follows the R.I.C.E. approach:
Resting the knee by ceasing the activity that caused the injury, as well as any activities that may aggravate it. A hinged knee brace can help to prevent any additional hyperextension while the injury heals.;
Applying ice or a cold pack to the knee several times a day(say for 20-30 minutes at a time, every 3-4 hours);
Elevating the knee above heart level whenever lying or sitting down.
In severe cases, knee hyperextension can result in tearing or rupturing of knee ligaments. ACL Tear injuries are especially likely to occur together with severe knee hyperextension. Severe ligament damage (tearing or rupturing) require correction via surgery.
How Much time May Be Needed For Recovery?
The recovery time from a knee hyperextension depends obviously on the severity of the injury. A mild to moderate injury that requires conservative treatment may take 2-4 weeks for recovery.
However, if surgery is performed to repair a torn or ruptured ligament, the patient may need a much longer time (as much as 6 months in some cases) to recover.
After the surgery, the patient should start a program of rehabilitative exercises as soon as possible to strengthen the knee and return it to normal function.
His or her doctor will usually make a referral to a physiotherapist to prescribe an exercise program and supervise the rehabilitation process.