Can we replace this old surgical technique?

Since the beginning of spinal surgery, patient’s own bone has been used for transplantation, for example when the vertebrae are fused together to treat back pain. But the resulting fusion is not optimal, in part because these transplanted bone pieces quickly die and dissolve. As a result, the body has insufficient time to form new bone at the site of transplantation. A recent study by UMC Utrecht, published in the scientific journal ‘Spine’, shows that special grains of artificial bone may be a better option.

Spinal fusion as treatment for back pain

Patients with back pain sometimes benefit from having several vertebrae attached to each other through 'spinal fusion.' Surgeons now use ‘autologous’ bone for this, which is bone taken from elsewhere in the patient's body, such as the iliac crest. Although this has been the best available treatment for about a century, it is not optimal. As the transplanted bone is broken down by the body faster than it creates new bone, it only leads to bone fusion between vertebrae in half the cases.

A study of regenerative treatment

The now-published MAXA study brings together two areas of focus at UMC Utrecht. UMC Utrecht is a center of expertise for spinal deformities, where patients are treated in the Mobility clinic. Additionally, there is a lot of research into regenerative medicine. This is a form of medicine that helps the body repair itself. That can be done, for example, with smart materials, which is also what this study is focused on.

Special granules of biodegradable ceramic have been developed, the shape and texture of which stimulate the body to grow bone. The study compared the beads to autologous bone in patients receiving vertebral fusion. Each patient was treated with their own bone on one side of the vertebral fusion, while the beads were placed on the other side. After one year, a CT scan was used to assess whether a bone connection had formed between the vertebrae on both sides.

Regenerative artificial bone appears superior to patient’s own bone

The results of the study exceeded expectations. Hilde Stempels, coordinator of the study, reflects: 'Our goal was to show that this new artificial bone does not perform worse than a patient’s own bone, the use of which has many disadvantages. So the fact that the beads now seem to work so much better than the bone is really quite extraordinary.' As this study did not yet aim to demonstrate superiority, the researchers call for further research. 'We will soon be able to analyze our patients' 2-year CT scans. But we are also curious to see if other research groups find similar fusion scores. Perhaps with a different study design or for a different application.'

Synthetic bone has more benefits

If these promising results hold up with more research, it would benefit this type of surgery in more ways. Orthopedic surgeon and professor of Reconstructive Skeletal Engineering Moyo Kruyt: "The purpose of regenerative bone was to replace autologous bone. But now that it is giving better results, it is potentially a solution to challenges for which we currently do not have a good treatment, such as poorly healing fractures. What is also great is that this is a relatively simple material and could therefore easily be registered as a medical implant. That is a big advantage over much more complex technologies we are working on.'

Towards a regenerative treatment for back pain

Hilde presented the study results at the Nordic Orthopedic Federation congress and immediately won an award for the best presentation. There, too, the impact these findings could have on current treatment strategies was noted. 'It is quite extraordinary that for the first time in history we have a regenerative product that not only meets all the conditions, but seems to exceed them,' Moyo says.