A spinal injury in March 2007 during his national service in the police force left Mr Alvin Mercado wracked with bouts of intense back pain and unable to walk.

Mr Mercado, who was 22 then, was active in sports and an avid basketball fan.

He feared he would never walk again.

Two slipped discs were the chief cause of his severe back pain.

Spinal surgery in August that year gave him hope that he would walk again.

The surgeon from Singapore General Hospital (SGH), where the operation was done, told him that the chance of success was very good - about 90 per cent.

However, to his despair, Mr Mercado, now 24, found himself among the 10 per cent of cases who have failed back surgery syndrome.

Dr Ho Kok Yue, a consultant and director of the acute pain service department of anaesthesiology and deputy director of the Pain Management Centre at SGH, was one of the doctors who treated Mr Mercado.

Dr Ho said that sometimes patients continue to have persistent back pain even after surgery has been successfully performed.

On top of the excruciating pain Mr Mercado still felt, his condition also began to deteriorate.

His legs started to weaken till he could no longer carry the weight of his body.

He became wheelchair-bound.

His mother, Mrs Frances Mercado, 43, said: "It was painful to see my son suffer from what we thought would be a lifelong disability."

She decided to give up her job as an administrative assistant to care for her son, who now needed help in daily activities like bathing and using the toilet.

His dad, Mr Tony Mercado, 52, a project manager for a multinational corporation, became the sole breadwinner for the family of nine.

Mr Alvin Mercado, who is the eldest of seven children, said: "I became depressed as I saw my dreams and ambitions fade away. I felt that my polytechnic education had gone to waste because it would be difficult to find a job with my disability."

>> Next page: Second surgery ruled out

He had graduated with a diploma in Information Technology.

A second spinal surgery was ruled out as it would not help him.

However, Dr Ho found another solution: a small device in the form of a spinal chord stimulator called Medtronic Restore. Two electrical leads were surgically implanted in Mr Mercado's spine and tunnelled under his skin to be attached to a rechargeable battery which was inserted in his abdomen.

"Spinal chord stimulation has been shown conclusively in numerous scientific studies to be able to help patients with failed back surgery syndrome," Dr Ho said.

"The device produces electrical impulses which interrupt pain signals in the spinal cord before they reach the brain. Pain sensation is therefore replaced with a tingling sensation."

Following the procedure, which was done in May last year, Mr Mercado's condition improved. The level of pain he felt in his left leg was reduced by 40 per cent.

With intensive physiotherapy, he soon regained his ability to walk.

"The feeling of being able to stand up and walk on my own was indescribable. I was overwhelmed with joy," he said.

Even though the device does not provide a cure for his condition, Mr Mercado, who now walks with a crutch, is grateful for this second chance at leading a normal life.

He can now indulge in his hobby of cooking and has found a job as an IT support staff member for a government project. "I used to be helped by people but now I am happy to be given this opportunity to help others," he said.

While he cannot participate in sports, he has learnt much from his experience. "I now understand the challenges and discrimination that disabled people face daily," he said. "I have a lot of respect for them."

His mother, who echoes his joy, said: "I am very happy for my son. He has been given a new lease of life."

charkhoo@sph.com.sg

This article was first published in Mind Your Body, The Straits Times.