askST: Is stem cell therapy for osteoarthritis approved in Singapore?

Reader Sam Tay wrote to askST about an old article in The Straits Times about a therapy to treat those with osteoarthritis using stem cells.

He would like to know whether this procedure is approved for use in Singapore and if approved, where one can seek such treatment.

Ng Wan Ching, editor, Mind&Body, finds an answer.

Stem cell therapy involves harvesting mesenchymal stem cells from either the bone marrow or adipose tissues (fats), multiplying them in the laboratory and then injecting these stem cells into the affected organ or joint.

These cells are capable of regeneration and differentiating into various cell types.

Stem cells can be induced to become cartilage, bone, tendons and so forth.

It is thus this hope, that stem cells can be used to replace any injured cells, and regenerate any injured organs, that makes stem cell therapy so attractive, said Associate Professor Denny Lie, senior consultant in the department of orthopaedic surgery at the Singapore General Hospital.

However, in elderly patients, where arthritis is severe, even stem cell therapy would have limited use, he added. Currently, stem cell therapy is not officially approved as mainstream treatment for osteoarthritis here.

For elderly patients with severe arthritis, the condition can be debilitating and negatively impact lifestyle, said Prof Lie. For such patients, a knee replacement is usually recommended.

The condition, which affects up to 40 per cent of patients aged 70 years and above, is a chronic degenerative disorder of the joints, a form of "wear and tear" which usually involves the knee and hip joints.

Certain risk factors can predispose a person to arthritis. These include obesity and previous injuries or infections to the joint.

Joints inflicted with arthritis are usually swollen, painful and have limited movement. Up to a quarter of such patients have difficulty in daily living, said Prof Lie.

Occasionally, young patients (up to 40 years of age) seek medical help for knee pain after sports or injuries.

A magnetic resonance imaging scan (MRI) is often done to rule out ligament and meniscus injuries, said Prof Lie.

An MRI is also useful to diagnose and visualise cartilage ulcers, which if left untreated, could lead to early arthritis, he added.

Cartilage ulcers can be treated by arthroscopic (key-hole) surgery only if they are not bigger than 4cm in diameter, well contained, meaning it is surrounded by a rim of healthy cartilage, and have healthy bone at the base of the ulcer.

There are a few available treatment options for those with cartilage ulcers and osteoarthritis, said Prof Lie. He outlines the options:

1. Hyaluronic acid injection and platelet-rich plasma injection

Hyaluronic acid injections (like Synvisc, Monovisc) are frequently used in the clinics and serve as a lubricant for the knee. It can help reduce inflammation of the knee but it does not regenerate the damaged cartilage.

Another injection used is the platelet-rich plasma injection. In this technique, about 10 mls of blood is drawn from the patient and spun in a centrifuge to separate the plasma from the red blood cells. After filtering the plasma, the platelet-rich component is then injected to the affected joint.

As a concentrated source of autologous platelets, it contains several different growth factors that can stimulate healing of bone and soft tissue.

International studies have shown patients do feel better after platelet-rich plasma injections but this injection is currently not approved in Singapore for use in arthritic conditions.

2. Arthroscopic microfracture and chondroplasty

This is the most common arthroscopic (key-hole) procedure performed for patients with mild arthritis. The cartilage ulcer base is cleaned up, its edges smoothed out and small perforations (holes) are made in the base of the ulcer.

This will enable blood and stem cells from the bone marrow to be released and help in the healing of the cartilage ulcer. The blood will form a fibrin clot and over time, fibrocartilage which is similar to the native original hyaline cartilage, is formed.

Though this is not the actual hyaline cartilage being regenerated, the fibrocartilage acts as a scar that reduces pain and hopefully prevents progression of the injury.

Though this involves stem cells which are released from the bone marrow, it is different from stem cell therapy which involves harvesting stem cells, multiplying them before injecting them for therapeutic purposes.

3. Cartilage patch repair

Cartilage ulcers can also be patched up, much like covering up a pothole on the road.

In suitable patients, the arthroscopic surgery involves cleaning up the cartilage ulcer (chondroplasty), making holes (microfracture) then patching up the ulcer with a hyaluronic acid patch.

The patch eventually coalesces with a blood clot and forms a layer.

Over a period of three to six months, the patch which acts as a scaffold for cells, becomes re-populated by the patient's cells and hopefully becomes similar to the native cartilage.

4. Cartilage transplant

In order to fill up a cartilage ulcer, healthy cartilage cells can be harvested and multiplied in the laboratory. These can then be transplanted to the cartilage ulcer, either with a scaffold or with a gel matrix.

Cartilage transplant is expensive and needs about six weeks to multiply the healthy cartilage. This option is available at the Singapore General Hospital but is not popular.

In younger patients, when the cartilage injury is minimal, they can see an orthopaedic surgeon and explore the available options, said Prof Lie.

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