China experts perform human spinal disc transplants

HONG KONG (Reuters) - Doctors from China and Hong Kong have transplanted human spinal discs into five patients in mainland China, offering what could be a viable alternative to treat degenerative disc disease (DDD) in the future.

The soft, compressible discs that separate the interlocking bones that make up the spine can break down with age, becoming drier, less flexible and more easily damaged.

They act as shock absorbers for the spine, allowing it to flex, bend and twist, but slipped discs can affect nerve function, leading to numbness and pain in a leg or arm.

Writing in the latest issue of the Lancet, researchers said they transplanted spinal discs from three young female donors who had died from trauma into five patients suffering from DDD from March 2000 to January 2001.

"This is the first human disc transplant in the world. The operations took place in the Navy General Hospital, Beijing," Keith Luk, chair professor and head of the Department of Orthopedics & Traumatology at the University of Hong Kong, wrote in an e-mail to Reuters.

The patients were closely monitored for 5 years.

The researchers wrote: "The neurological signs and symptoms of all the patients improved after the operation ... none of the patients had any persistent or clinically significant neck pain at rest or during neck movement."

VIABLE FUTURE TREATMENT?

Luk said human spinal disc transplants could become a viable future treatment for DDD with further improvements.

"We are performing further research into the kinematics of the grafted disc, how to better preserve the grafts, how to prevent early degeneration of the grafts, and whether we can repopulate the graft with the recipient's own cell," he said.

In an accompanying comment published in the journal, experts not involved in the study said human disc transplantation may provide an attractive alternative to current treatments, such as spinal fusion and artificial disc transplants.

Spinal fusion permanently connects two or more bones in the spine to improve stability, correct a deformity or treat pain. In some cases, bones, rods and screws are used to fuse vertebrae.

But areas of the spine adjacent to the fusion will bear more stress, making them more vulnerable to future wear and tear.

"The feasibility of the technique has now been shown and disc transplantation could be an attractive alternative both for fusion and artificial disc replacement, providing an appropriate donor is found with adequate geometry," wrote Wafa Skalli and Jean Dubousset at Biomechanics Laboratory in France.

"This approach could be of particular interest for younger patients for whom prevention of adjacent-level degeneration is important."

Luk added: "This will be one of the surgical options for DDD patients, instead of a fusion where the segmental motion will be lost, or an artificial disc implant where a revision will be difficult and risky in the long term."