07 Jul 2011
By: JOAN CHEW
At first, it was her feet. They felt sore whenever she walked.
Then her ankles, knees, hand and wrist joints were affected.
The pain was uneven. The left side of her body hurt more than her right.
She was 38 then and diagnosed with rheumatoid arthritis – an autoimmune inflammatory disorder which causes the immune system to attack its own joints.
No one really knows the cause.
But retiree Tang Geok Lee, 59, knows the pain.
She has lived with it for 21 years.
She was put on medication to control the inflammation and provide pain relief, but after a few years, these did little to help her left hand.
Her left hand gave her the most grief. Whenever she used it to pick up items, or accidentally knocked it against something, she felt as though a knife had sliced through it, she said in Mandarin.
When it got cool at night, the pain emanating from her left wrist intensified and kept her awake.
These days, she has been given a reprieve.
Last November, she went through a landmark operation to replace her wrist joint with an artificial implant designed to function like a normal wrist.
Tan Tock Seng Hospital (TTSH) said Madam Tang was its first such patient.
Checks with public and private hospitals here showed no others had carried out such a procedure, although they have doctors who have been trained to do so.
Dr Lim Beng Hai, who runs his own practice at Paragon, is scheduled to perform his first wrist replacement surgery on a patient in his late 30s next Tuesday.
The procedure, also known as wrist arthroplasty, can benefit those whose joints have been damaged by arthritis or in accidents.
About 0.5 per cent of the population have rheumatoid arthritis. Madam Tang’s surgeon, Dr Winston Chew, head of the hand and microsurgery section at TTSH, said the wrist would be affected to some degree in almost every patient.
More common among the population is osteoarthritis, which affects one in five women and one in 10 men who are over 60 years old. But fewer than 10 per cent of patients with osteoarthritis have their wrists affected, he added.
Patients with wrist problems similar to Madam Tang’s usually undergo surgery to fuse their wrists. This is done by screwing the bones in the wrist to a metal plate or pinning the bones together.
The procedure can involve fusing all, or just some, of the bones in the wrist, depending on the severity of the arthritis.
In partial wrist fusion, the two rows of bones at the base of the hand, called the carpal bones, are fused together.
Alternatively, the first row of the carpal bones is fused with the larger of the two bones in the forearm called the radial bone.
Partial wrist fusion preserves between 30 and 70 per cent of wrist mobility, said Dr Andrew Chin, head of the department of hand surgery at Singapore General Hospital.
The more drastic process, total wrist fusion, involves fusing both rows of carpal bones with the radial bone.
The result: The patient can no longer move his wrist in a circle, although he is still able to rotate his forearms.
Dr Lim said that was why his patient, a chef, would not opt for a total wrist fusion.
The chef was also not suitable for a partial wrist fusion because he had lost half his wrist through osteoarthritis in 2000.
A recent road traffic accident destroyed the remaining joints in his wrist, so he required surgery again.
As he relies on his hands for a living, he opted for a wrist replacement, which would retain between 50 to 80 per cent of his wrist movement, said Dr Lim.
Likewise, Madam Tang said she jumped at the chance to undergo wrist replacement surgery, which promised to eliminate her pain while retaining most of her wrist movements.
The X-rays of her left wrist showed that the cartilage between her bones had worn away so much that the bones were rubbing against one another.
Due to inflammation from her rheumatoid arthritis, her carpal bones had also fused into one block, resulting in a very stiff wrist that was limited in its range of motion, said Dr Chew.
During the operation, which lasted nearly four hours, a 10cm incision was made on the back of her left wrist and the tendons pulled apart to reach her bones.
Parts of the radial bone and the carpal bones were removed and the implant – made of cobalt chrome with titanium coating and a high-quality plastic called polyethylene – was inserted into her wrist.
For the next two months, Madam Tang wore a brace to support her wrist.
A week after surgery, she began physiotherapy sessions to exercise her fingers and strengthen her left hand and wrist.
She needed physiotherapy for three months.
With the implant expected to last 10 to 15 years before it loosens or fails due to wear and tear, there is every chance that Madam Tang will require a second surgery in future.
Then, she could either re-insert another implant or choose to have her wrist fused, said Dr Chew.
Dr Chin said as Singaporeans live longer, it is likely that patients who have undergone a wrist replacement will require revision surgery to the affected wrist in their lifetime.
Dr Chew said although wrist replacement surgery is less common worldwide than wrist fusion, it is not riskier.
As with any other surgery in which a foreign object is inserted into the body, the most immediate complication would be an infection of the wrist joint, he said.
If this happens, a second operation would be required to remove the implant to treat the infection, followed by a third operation to fuse the remaining bones.
Dr Chin added that other complications include nerve and tendon injuries, dislocation of the wrist bones from the implant and failure of the implant.
Fortunately, Madam Tang did not encounter any of these problems.
She declined to reveal the cost of her surgery and hospitalisation, saying only that her insurance took care of the full bill.
At TTSH, wrist arthroplasty costs between $10,000 and $20,000, with the implant alone costing $5,000 to $8,000. This is about double the cost of a wrist fusion.
Madam Tang said: “In the past, my left hand had no strength but now I can carry things with it.”
But she is aware that the lifespan of the implant will depend on how carefully she uses her new wrist.
She said: “When I have heavy grocery bags, I will use a shopping trolley rather than carry them with my hand. I hope the implant will last for as long as possible.”
Email: joanchew@sph.com.sg
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