When people mention knee 'cartilage' injury, they are usually referring to the meniscus.
However, the surface of the bones inside the knee joint is covered by a smooth glistening tissue called cartilage. This cartilage has a high water content and helps in smooth, friction free movement of the joint and the it is nourished by the joint fluid, which is minimal in content normally.
This lining when damaged can cause pain and this is the tissue which gets thinned out and often disappears in arthritis.
Minor damage or thinning out of the cartilage, especially if away from the weight bearing regions of the joint, does not cause any symtoms. However, if it involves the crucial weight bearing areas of the joint, this can lead to severe pain and disability.
Symptoms of Cartilage problem
Pain, especially when walking.
Pain on climbing stairs.
Grating sensation inside the knee
Discomfort and difficulty when standing up after prolonged sitting (like after driving, cinema seat, toilet seat)
Stiffness and decreased range of movement.
The diagnosis is usually made by your doctor after a thorough assessment of your knee including a history and physical examination. This will usually be supported by X rays and MRI scan.
What is the treatment for cartilage damage?
Conservative treatment - some patients respond well to conservative (non-surgical) treatment, which may include special exercises, the use of NSAIDs (non-steroidal anti-inflammatory drugs), and maybe a steroid injection. Exercises may include physical therapy (physiotherapy) and/or a program the patient can do at home. If the damage is not extensive, this may be all the patient needs (without surgery).
Surgery - patients who do not respond to conservative treatment will need surgery. There are several surgical options. The surgeon will recommend one based on several factors, including the age and activity level of the patient, how big the lesion is, and how long the injury has been present. Surgical options include:
Debridement - smoothing the lesion and removing loose edges to prevent irritation. The procedure is done using small arthroscopic instruments, such as a mechanical shaver.
Marrow stimulation - under the damaged cartilage the surgeon drills tiny holes (micro fractures), exposing the blood vessels that lie inside the bone. This causes a blood clot to form inside the target area of the cartilage. The blood cells trigger the production of new cartilage. One drawback is that this procedure does not produce the desired type of cartilage - fibro cartilage instead of hyaline cartilage (which is much more supple). Fibro cartilage is will wear away more quickly and the patient may need further surgery later on.
Mosaicplasty - cartilage from undamaged areas of the joint is moved to the damaged area. The cartilage that is moved has to be in a non-weight-bearing part of the joint. This procedure is not suitable when there is widespread damage, as in osteoarthritis. This treatment is only recommended for isolated areas of cartilage damage, generally limited to 10-20mm in size, most commonly found in patients under the age of 50 years who experienced an injury in the affected area.
Autologous chondrocyte implantation (ACI) - a small piece of cartilage is taken from, for example, the knee (biopsy) and sent to a laboratory which grows more cartilage cells from the sample. About 1 to 3 months later the new cartilage cells are implanted into the knee. A piece of outer layer of bone from the lower leg (periosteum) is taken and sewn into the area of cartilage damage. The cartilage cells that were cultivated in the lab are then injected into that area and the periosteum is sealed - the cartilage then grows back. This treatment is quite expensive and only available in certain centres.
What are the possible complications of articulate cartilage damage?
If left untreated, the joint, especially if it is a weight-bearing one, such as the knee, can eventually become so damaged that the person cannot walk. Apart from immobility, the patient may experienced progressively worsening pain.
Dr Vinod Kumar Abu Dhabi
Sports surgeon Abu Dhabi
Shoulder surgeon Abu Dhabi
NMC Royal Hospital
Knee Cartilage injury
Normal Articular cartilage (above)
Arthroscopic view of normal cartilage (below)