SINGAPORE - Osteoarthritis may be a degenerative joint disease, but it is certainly not just an old person's disease.
Doctors said more young people are also seeking help for this most common form of arthritis.
Dr Yoon Kam Hon, a consultant rheumatologist at the department of medicine at Changi General Hospital, who also runs his own private practice at Towner Road, said one to two out of every 10 osteoarthritis patients he has seen in the last three years are younger than 50 years old, compared with one out of every 30 previously.
Dr Kevin Lee, the medical director of Singapore Medical Group's Centre for Joint & Cartilage Surgery and Singapore Sports Orthopaedic Surgery Centre, said four in every 10 patients he sees are below 65 years old, up from just one in every 10 a decade ago.
At Singapore General Hospital (SGH), 30 per cent of osteoarthritis patients are aged 45 to 60. The reason is because more people are exercising and they are exercising too hard or infrequently, both of which are hard on the joints. Osteoarthritis is caused by the gradual deterioration of the cartilage - the tough material which protects the ends of the bones where they meet and form the joint, thus ensuring the joint works smoothly.
In primary osteoarthritis, this is probably influenced by genetics, hormones, a person's activity level and the alignment of the lower limbs, said DrDarren Tay, a consultant at the department of orthopaedic surgery at SGH.
Doctors agree that secondary osteoarthritis, however, is caused by various types of trauma to the joints. The degeneration could be triggered by inflammation from diseases such as lupus and gout, a previous infection of the joint or injury to the bone or ligament.
These are the likely reasons young patients have osteoarthritis.
In recent years, a surge of interest in long-distance running has contributed to more people getting the disease.
While exercise itself is not considered bad for the joints, it becomes a problem when people do not properly condition their bodies or neglect sporting injuries.
Dr Benedict Tan, the head and senior consultant at Changi Sports Medicine Centre at Changi General Hospital, said a common sports injury which snaps the anterior cruciate ligament (ACL) in the knee is likely to damage the cartilage too, though it may not be immediately apparent to the athlete.
He said: "The cells that form the scaffold for the cartilage may die from the injury, but it takes some time before the scaffold collapses."
This is why the symptoms of osteoarthritis, such as pain and stiffness, may manifest only years later.
In any case, people should take more care because even when injuries of the meniscus (the shock-absorbing cartilage in the knee joint) or ACL are treated, a person may get back only 60 per cent of what their knee function used to be, warned Associate Professor Wilson Wang, head and senior consultant at the division of hip and knee surgery at National University Hospital.
It is not known how common osteoarthritis is here, but in South-east Asia, 5 per cent of women and 3per cent of men aged 40 to 60 have osteoarthritis of the knee, Prof Wang said.
In those above 60, the incidence goes up to 15 per cent for women and 10 per cent for men.
Out of every three patients with osteoarthritis of the knee, two will be women, said Dr Lee.
No one really knows why, though their wider hips and hormonal changes, which affect the tension of ligaments, are thought to be possible reasons.
After a diagnosis of osteoarthritis is confirmed with an X-ray, treatment is aimed at addressing the symptoms, such as muting the pain with medication, and protecting the joints through weight control.
When the disease has progressed to the point when a person can no longer walk the distance of one bus stop without pain, surgery is an option.
A total of 3,169 knee replacements were performed in public hospitals here last year, said the Ministry of Health.
This is a 30 per cent increase from 2007, which had a total of 2,418 knee replacement cases.
Dr Lee estimated that nine in 10 of these knee replacements are due to osteoarthritis.
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