Most people will suffer from cartilage damage at some point in their lives. In most cases the knee joint is involved. There are a number of symptoms which point to cartilage damage, including pain in the joints, stiffness, swelling and a lessening of movement in the relevant joint. Cartilage is an extremely flexible yet tough tissue that is found in all areas of the body. It has two principle functions: as a shock absorber and as a mould.
All the joints within our body are covered with cartilage. The presence of the cartilage enables our bones to move over one another smoothly — it reduces friction and therefore the potential for damage. It helps support the weight of movement, whether that is walking, stretching, bending or running. Knee cartilage damage is particularly common and treatment can vary depending on the extent of the damage sustained.
Cartilage tissue is flexible and tough, and its purpose is ideally illustrated when it comes to our more unique features, such as the nose and ears. These two extremities consist almost wholly of cartilage.
What marks cartilage out from other types of tissue is its lack of blood supply. Blood cells play a very important part in the process of repair if our tissues become damaged. It therefore follows that knee cartilage damage and other common cartilage issues are unable to be repaired in the same way as damaged muscle or skin.
Cartilage is divided into three types. These comprise the following:
Hyaline Cartilage: Principally found between the joints and ribs and around the trachea (windpipe)
Elastic Cartilage: More flexible and supple and makes up much of the nose, outer ear and epiglottis
Fibrocartilage: The strongest type of cartilage is fibrocartilage. This can withstand a great deal of weight and is found between the bones of the pelvis and hips and, crucially, between the vertebrae. Knee cartilage damage involves the fibrocartilage.
One of the most often reported and possibly serious sorts of damage is that to the cartilage between a joint — commonly knee cartilage damage. This type of injury can lead to swelling, pain and varying degrees of mobility loss.
However, all types of cartilage can become damaged. A common injury is the one known as 'cauliflower ear', where the elastic cartilage becomes damaged, leading to an appearance of deformity. This type of injury is very common among rugby players. Many people suffer from damage to the fibrocartilage that separates the vertebrae. Known as a 'slipped disc', this can be excruciatingly painful.
Symptoms of Cartilage Damage
The most common symptoms of knee cartilage damage are pain, stiffness, reduced movement and swelling. A high-quality support product can compress the area to reduce pain and swelling, whilst stabilising the area involved.
This can be important as cartilage damage can take some time to repair itself. This type of tissue does not have its own supply of blood providing the cells that help to repair damage, meaning that it does not heal as fast as muscles or skin, for example.
Sources of damage
Knee cartilage damage typically involves meniscal injury, although articular cartilage injury, known as chondral injury, or osteochondral injury if there is also damage to the underlying bone, can also occur. Knee cartilage damage usually occurs as part of a twisting injury to the knee, and often in association with damage to other soft tissues. Initial treatment involves rest, icing, compression and elevation, while the use of a knee support can help protect against further injury. Further treatment will depend on the age and general health of the patient, the impact of the injury, and the severity of the symptoms. Untreated articular cartilage damage may lead to the early onset of osteoarthritis.
Articular cartilage does not contain blood vessels or nerve endings, but pain can still be experienced by patients. 'Locking' can occur when a piece of damaged cartilage hinders the smooth movement of the joint. The knee may become swollen, and weight-bearing activities can be painful.
Diagnosis of articular cartilage damage involves analysis of injury history and examination of joint for swelling, locking and 'crouching'. X-rays can help with the diagnosis, but MRI scans provide the most objective data for diagnosing knee cartilage damage.
Menisci are rubber-like C-shaped pads of cartilage which sit on top of the thin cartilage layer which covers the top of the tibia. These cartilage pads absorb the shock caused by impact between the upper and lower leg, improve stability and aid smooth movement of the joint. Meniscal damage involving a partial or full tear, tends to occur during a forceful knee movement in a leg which is bearing weight. This is very common in sports such as football, rugby and skiing, when the athlete twists or rotates the knee of a weight-bearing leg. The location of the tear within the meniscus, and the length of the tear will determine the seriousness of the injury. In traumatic injuries, the cartilage damage is often in addition to ligament tears or sprains. Injury can also occur as a result of repeated minor trauma to the area, or general wear and tear.
Diagnosis of meniscal knee cartilage damage typically involves physical examination, and confirmation by MRI scan or arthroscopy. Symptoms may disappear after a few weeks, but for most people, pain can persist long-term until the tear is treated. Use of a knee support may protect against further injury in the initial stages, and help to reduce pain from swelling.
The simplest and most rudimentary non-surgical treatment for cartilage damage is the prescription of painkillers such as ibuprofen or NSAIDs that help alleviate pain and reduce swelling. In addition to painkillers, knee support such as a brace or bandage may be utilised to prevent further knee cartilage damage and give the existing injury time to heal.
Physiotherapy is often used with great success and physio-controlled exercises that strengthen supporting muscles can offer huge relief and reduce pressure on the joint effectively. Lastly, a common non-surgical treatment to either cure or prevent knee cartilage damage is a lifestyle change. By reducing activities that affect the joint sufferers are less likely to incur injury and further damage.
Non-surgical treatments may, however, only perform short term relief and in extreme or serious cases there may be no other alternative than surgery.
There are several surgical treatments that are used in repairing and alleviating the pain from knee cartilage damage and the procedures and what they entail are as follows.
Arthroscopic lavage and debridement
This technique is used when cartilage pieces have become loose within the joint, causing it to lock. An arthroscope is used to assess the damage and the joint is then cleaned using saline solution. Once clean, the loose cartilage fragments are removed using a shaver and the small incisions made to complete the procedure are closed. This common surgical procedure does not repair damaged cartilage but is designed to alleviate the pain it causes and increase mobility.
In this procedure tiny holes are made in the bone in order to release bone marrow which in turn leads to a blood clot forming in the damaged cartilage, stimulating the production of new cartilage. This surgical procedure may have a limited lifespan as new cartilage may also wear down and have to be replaced in future.
Mosaicplasty and Allograft osteochondral transplantation (AOT)
Mosiacplasty is a technique where tiny rods of healthy cartilage are used to replace damaged cartilage. If the damage is too severe then Allograft osteochondral transplantation is offered as an alternative, and donor cartilage is used to perform the procedure.
Autologous chondrocyte implantation (ACI)
This two-stage technique begins with a small sample of cartilage being removed during an arthroscope and then being sent to a lab where new cartilage cells are grown in an artificial environment. The new cartilage is then used to replace the damaged cartilage via a collagen patch that is placed on the affected area.
This new technique involves implanting a frame made up of collagen and proteins which then stimulates growth of cartilage cells. The frame is slowly absorbed, leaving behind healthy cartilage.
Knee cartilage damage is a common occurrence and can often be addressed by simply easing off on certain activities or by ensuring adequate knee support is offered when strain is placed on the body. Researchers continue to address the techniques used in treating this ailment and new surgical procedures may be available within the next few years.