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What knee injuries in early life can lead to osteoarthritis in the future?29th June 2017
There are many factors that can increase the likelihood of developing osteoarthritis later on in life. People over the age of forty are more likely to have osteoarthritis than younger people, because the joints become worn, the muscles get weaker and the body is generally less able to heal as you grow older. Weight is another important factor, and overweight people are at higher risk of developing osteoarthritis, as are those who have physically demanding occupations that involve difficult repetitive activities. Osteoarthritis is more prevalent among women than men and there is sometimes a family predisposition towards the development of the condition.
Other factors that can predispose to osteoarthritis
Many knee injuries can lead to the development of osteoarthritis in the future, so even if you do not belong to any of the higher risk groups outlined above, a knee injury such as an Anterior Cruciate Ligament (ACL) injury or a torn meniscus can cause osteoarthritis in the knee years later. The knee is one of the most commonly injured joints, because it is involved in weight bearing and its anatomy is quite complex.
Operations on the knee, such as a repair to the cruciate ligaments or a meniscectomy, where the damaged cartilage is removed, can also make the development of osteoarthritis more likely. Diseases that affect the joints such as gout and rheumatoid arthritis are also predisposing factors.
Sprains and tears to the anterior cruciate ligament are very common among athletes. Surgery is frequently needed in order to restore complete function to the knee, but this depends on factors such as your activity level and the severity of the injury.
Causes of ACL injuries include stopping suddenly, making rapid changes in direction, slowing down when running, collision or direct contact and landing incorrectly from a jump. Some studies suggest that the incidence of an ACL injury is higher in female athletes than male athletes and this is thought to be due to differences in factors such as muscular strength, physical conditioning and neuromuscular control. Other possible causes include looser ligaments, the effects of estrogen on the ligaments and differences in the alignment of the pelvis and legs.
ACL injuries often occur (about 50% of the time) at the same time as other parts of the knee are damaged, such as the meniscus or other ligaments or cartilage. Ligament injuries are usually categorised according to their severity as grade 1, grade 2 or grade 3 sprains. A grade 1 sprain means that there has been mild damage to the ligament and although it has been slightly stretched, it can still help with keeping the knee joint stable. A grade 2 sprain may also be called a partial tear, and is when the ligament has been so stretched that it has become loose. A grade 3 sprain is actually a complete tear and the ligament is split into two, causing the knee joint to become unstable.
The symptoms of an ACL injury include sometimes hearing a popping sound and feeling as though the knee has given way. Pain and swelling are also common, as are being unable to move the knee to its full range and discomfort when walking.
Treatment options can vary depending on the age and activity level of the individual. For example, a young athlete will normally need surgery before being able to safely return to their sport or activity. Sometimes an older or less active person may be able to continue without surgery, as long as their activity levels are low and they do not expect too much from their knee.
Non-surgical treatment of an ACL tear that may be recommended for these patients, as long as their knee is relatively stable, could include bracing and physiotherapy. A brace can be used to protect the knee against instability and, in some cases, may be combined with crutches, which will prevent too much weight-bearing. Physiotherapy will include exercises to strengthen the muscles and restore function to the knee.
Unfortunately, the torn ligaments are not usually easy to repair surgically and cannot simply be stitched back together. The ligament normally needs to be reconstructed in order to restore the stability of the knee. This is done by replacing the torn ligament with a graft, to provide a platform on which a new ligament can grow. There are several different sources of grafts that can be used. These include grafts from the patellar tendon that is found between the shinbone and the kneecap, or the hamstring tendon that runs down the back of the thigh. Less commonly, a quadriceps tendon may be used. This runs from the kneecap to the thigh. Sometimes a cadaver graft is used. All the different sources of grafts have their advantages and disadvantages, and your surgeon will be able to help you understand which will be most suitable for you. Since regrowth of the tendon takes some time, it can be several months before a return to your sport or activity is possible.
Surgery is not normally undertaken immediately following an injury, as the inflammation should be given a chance to resolve and some motion should be restored to the joint before the reconstruction is undertaken. Undertaking this kind of surgical reconstruction too early can increase the risk of excessive scar tissue or arthrofibrosis forming in the knee. This could cause a loss of motion in the joint.
Whichever form of treatment, surgical or non-surgical, that you have, physiotherapy is vital to restore strength and motion to the knee joint.
In addition to ACL tears, other knee injuries can also contribute towards the development of osteoarthritis in the future. Any of the tendons, bursae and ligaments that surround the knee joint can be affected by injury, as can the bones, menisci, ligaments and cartilage that actually form the joint. Trauma is usually responsible for these injuries and ligaments are usually initially treated by rest, immobilisation, ice and elevation, before surgical repair is undertaken.
Tears of the meniscus
These can occur when shearing forces of rotation are applied to the knee. This happens during rapid sharp motions in sport and is more common as people grow older. There may be a popping sensation, sometimes associated with swelling or instability in the knee joint. Tears to the menisci are diagnosed by arthrography, arthroscopy or MRI. They cannot be seen on routine x-rays. These injuries are usually repaired arthroscopically.
Tendinitis of the knee occurs when the patellar tendon at the front of the knee or the popliteal tendon at the back of the knee becomes inflamed. This can occur as a result of jumping and, in fact, patellar tendonitis is also known as “jumper’s knee”. Symptoms of tendinitis include pain and tenderness around the tendon and treatment consists of ice, bracing, rest and anti-inflammatory drugs. Gradual rehabilitation will help to restore movement and function. Although cortisone injections are commonly used for tendinitis in other parts of the body, they are not normally used for patellar tendinitis, since they have been associated with an increased risk of tendon rupture.
The breaking of any of the three bones in the knee can occur with severe trauma, such as motor vehicle accidents or other impact trauma. They may need immobilisation by using supports and sometimes require surgical repair soon. Knee injuries have been linked with an increased risk of osteoarthritis developing in later life, and young people who experience these should be targeted for primary prevention of osteoarthritis. This could include the use of braces to stabilise the joint and modification of high impact exercise, so that the possibility of further damage is minimised. It is also important that proper sports equipment is used and sports are undertaken safely to prevent further joint injuries.