Billion-dollar idea began with a pain in the neck

A Dunedin toolmaker may have found a solution to one of the world's fastest-growing medical problems - the pain in the neck.

Richard Cathro's invention, the CG Clip, could tap into a world market measured in the billions of dollars.

It is a creation from which Dunedin stands to benefit in jobs and investment, as the company, CG Surgical, plans to manufacture the clip and base research and development in the city.

Recovering from neck surgery in 1993, Mr Cathro and his surgeon, Grant Gillett, spent several years developing the 40mm by 16mm titanium and teflon clip-and-spring mechanism, which is surgically inserted into the neck.

It stops neck bones pinching or putting pressure on the spinal cord, increasing space for the cord and preventing ailments such as headaches, pain, numbness and pins and needles.

Since it was introduced by Healthcare Otago in 1995, 70 patients have received implants as part of a trial. In a study by Professor Gillett, between 65 per cent and 70 per cent noticed an improvement.

"This study indicates that the CG Clip is a safe technique with good patient outcomes," he said in a report.

Mr Cathro said that, traditionally, surgeons would graft bone from a patient's hip and place it in the cervical spine to achieve a similar result.

But that required two surgical procedures and patients suffered hip pain.

In comparison, the clip could be installed in under an hour - nearly a third of the time for a bone graft - it was easy to install, and it gave the patient mobility.

"A Southland farmer had suffered headaches for most of his life. Two days after the clip was installed, his headaches had gone," Mr Cathro said.

CG Surgical director Dr Alastair Clemow said cervical spinal problems were usually caused by bone touching the spinal cord.

The company said the potential market for the clip was massive.

Dr Clemow said back pain was the second most common ailment in the United States and last year alone Americans spent $US1.1 billion ($2.74 billion) on products to relieve spine pain and more than $US5 billion on spinal healthcare.

Mr Cathro said: "We believe this is the only type of product on the market which addresses this medical problem in this manner."

CG Surgical has secured patents in New Zealand, Australia, the US, Japan, Canada, Britain and Germany.

Mr Cathro said one proposal was a CG Clip package for surgeons which included the clip and tools to insert it. He was also developing other devices.

- NZPA