A hyperextended knee injury occurs when the ligaments are stretched beyond their normal range of motion, resulting in a strain or even a tear in ligament tissue. A person who hyperextends his or her knee usually notices the injury immediately; an individual may feel a popping sensation and notice immediate pain and swelling. Depending on the severity of a hyperextended knee injury, a person may not be able to walk or put weight on the hurt leg for several days after the accident. Doctors usually recommend that patients get plenty of rest, ice their knees occasionally, and engage in light exercises to regain flexibility and strength. Surgery may be necessary if the knee does not heal properly or a ligament is completely torn.
A knee can become hyperextended when it is twisted or bent in an awkward way. Knee injuries are very common in high-intensity sports when athletes make sudden turns or stop immediately. When too much stress is placed on the ligaments in the knee, they can become strained or torn, which leads to inflammation and intense pain. A strained ligament is usually considered a mild injury, and symptoms typically subside after about two weeks. A severely torn ligament, especially the anterior cruciate ligament, is extremely painful and often necessitates months of surgeries and rehabilitation to heal.
The first symptoms of a hyperextended knee are a popping feeling or noise as the ligament stretches beyond its normal range of motion, followed by pain and swelling. Even a mild injury can cause the knee to feel as if it is locked up, making it difficult or even impossible to bend and straighten it. Severe pain and swelling usually persists for several days after an injury without treatment, and a damaged knee may appear out of line with the rest of the leg.
An individual who believes he or she has this condition should consult a physician immediately to inspect the severity of ligament damage and recommend treatment. The doctor will perform a physical examination and possibly take x-rays to detect problems. For minor strains, a doctor will usually suggest prescription or over-the-counter pain medication and anti-inflammatory drugs, and instruct the patient to rest his or her knee as much as possible for about a week.
If a ligament has torn, the doctor usually arranges for surgical procedures and follow-up physical therapy. A surgeon may conduct an arthroscopic procedure or actually cut open the knee to survey the damage and decide on the best means of fixing a torn ligament. Reconstruction surgery is a common procedure in which the surgeon removes a less essential ligament from the knee or another part of the body, and puts it in the place of the torn ligament. Following surgery for a hyperextended knee, it is common to take up to nine months in rehabilitative physical therapy sessions to build back strength.