Doctors in China have carried out the world's first spinal disc transplants on five patients, a study says.
Back problems can cause excruciating pain
The discs were placed in the necks of four men and a woman by a University of Hong Kong-led team.
They were taken, with the consent of relatives, from the spines of three young female donors who had died suddenly as a result of trauma.
Five years on, the patients are doing well, with improved mobility and no immune problems, says the Lancet.
The surgeons said refinements of the procedure may provide an alternative to standard therapies.
But they said it would be hard to replicate the technique for spinal discs in the more complex area of the lower back - the most common source of problems.
Removing damaged discs and fusing adjacent vertebrae together is regarded as the "gold standard" treatment.
However, it results in limited movement and may accelerate degeneration elsewhere.
Artificial discs have shown success, but may produce serious complications in the neck region.
Vertebral discs are the spine's shock absorbers. The flat capsules, about an inch in diameter and a quarter-of-an-inch thick, fit tightly between the bones of the spinal column.
Under stress, a disc's inner material may swell, pushing through the tough outer membrane onto surrounding nerves and causing pain, which can be excruciating.
In severe cases, a ruptured or torn membrane may result in irreversible damage.
Disc problems can result from violent injury, or the strain caused by everyday activities and accidents, such as lifting heavy objects the wrong way or slipping on ice. Normal ageing can also lead to disc degeneration.
Transplantation has never been successfully carried out on humans until now.
The discs were removed from the donors within two hours of death and frozen in preservative chemicals before being transferred to the patients.
Professor Keith Luk, who led the team, said: "With further improvements in the areas of graft preservation and surgical techniques, disc transplantation could be indicated in degenerative disc disease."
But he said to extend the technique to the lower spine, which is more complex, would be a "challenge".
In an accompanying comment article, doctors Wafa Skalli and Jean Dubousset, from the ENSAM-CNRS research institute in Paris, said the transplants could open a "new dimension" in the treatment of degenerative disc disease.
They added: "Disc transplantation could be an attractive alternative both for fusion and artificial disc replacement.
"This new approach could be of particular interest for younger patients for whom prevention of adjacent-level degeneration is important."