There are a number of surgical and non-surgical treatments that can help relieve symptoms of damaged articular cartilage, depending on how severe the damage is.

Non-surgical treatment

Non-surgical options may include:

• physiotherapy – exercises that strengthen the muscles surrounding or supporting your joint, which may help reduce both pain and pressure on the joint
• painkillers – non-steroidal anti-inflammatory drugs (NSAIDs) can help reduce swelling and pain
• supportive devices – such as a cane or leg brace
• lifestyle changes – such as reducing activity that involves the affected joint

In more severe cases of articular cartilage damage, non-surgical treatment may only provide short-term relief and surgery may be required.

Surgical treatment

Surgical treatment for damaged articular cartilage includes the following procedures:

• arthroscopic lavage and debridement
• marrow stimulation
• mosaicplasty
• allograft osteochondral transplantation
• autologous chondrocyte implantation

These procedures are described in more detail below.

Marrow stimulation

Marrow stimulation involves making tiny holes called microfractures into the bone beneath the damaged cartilage using a small, pointed instrument known as an awl.

This releases the bone marrow from inside the bone and leads to a blood clot forming within the damaged cartilage. The marrow cells then begin to stimulate production of new cartilage.

The drawback to marrow stimulation is that the newly generated cartilage is fibrocartilage, rather than hyaline cartilage.

As fibrocartilage is not as supple as hyaline cartilage, there is a risk that after a few years it will wear away and further surgery may be needed.

Mosaicplasty

Mosaicplasty is a technique where small dowels (rods) of healthy cartilage from the non-weightbearing areas of a joint, such as the side of the knee, are removed and used to replace the damaged cartilage.

Mosaicplasty can be successful in most people. However, it is only suitable for treating relatively small areas of cartilage damage. This is because removing too much healthy cartilage could damage the section of the body where the cartilage was taken from. 

Before having mosaicplasty, your surgeon should discuss the possible risks and benefits of the technique with you.

Allograft osteochondral transplantation (AOT)

If damage to your cartilage is thought too extensive to be treated with mosaicplasty, an alternative procedure called allograft osteochondral transplantation (AOT) may be considered.

AOT is a similar procedure to mosaicplasty, but the cartilage is obtained from a recently deceased donor. The cartilage will be tested in a laboratory to make sure it is free from infection before being prepared for transplant. 

Unlike mosaicplasty, large areas can be covered by this technique. This procedure will need special funding from your clinical commissioning group (CCG).

Autologous chondrocyte implantation (ACI)

Autologous chondrocyte implantation (ACI) uses a two-stage technique. During the first stage, the surgeon takes a small sample of cartilage cells from the edge of your knee during an arthroscopy.

The cells are sent to a laboratory and placed in an incubator, where they are given nutrients to encourage them to divide and produce new cells.

After a few weeks, the number of cartilage cells will have increased from 2 to 20 million. The new cartilage cells are used to replace the damaged cartilage.

The second stage involves placing these cells on a collagen patch, which is then sutured or glued on to the damaged area, usually through a small incision.

After studying ACI, the National Institute for Health and Care Excellence (NICE) decided there is not enough evidence about the procedure's long-term effects or safety. The procedure is therefore currently only offered by very few hospitals.

However, a number of private clinics may offer ACI. The cost of treatment can be expensive and depends on the complexity of the operation. In some cases, you may have to pay in the region of £25,000.

Artificial scaffolds

A new technique being used to treat cartilage damage involves implanting an artificial scaffold into the damaged area. The scaffold can be either a patch or gel, and is usually made up of a combination of collagen and proteins.

They can be used in combination with microfracture or on their own. Some recent techniques include soaking the scaffold in bone marrow to attempt to use stem cells to repair the cartilage.

The frame helps bone marrow cells form cartilage, and is gradually absorbed over time until only the regenerated cartilage remains.

This technique is not currently widely available on the NHS, however.  

Ongoing research

A number of ongoing research projects are currently investigating more efficient and effective ways of repairing cartilage.

Examples of current research projects include:

• investigating ways of using different sources of stem cells to generate new cartilage (for example, bone marrow or fat)
• using donor stem cells to regenerate cartilage
• combining cartilage and stem cells to improve repair

Although these projects are still in the early stages, researchers are optimistic they will lead to new kinds of treatment.