1. Could you explain the significance of your article to the non-specialist? 

Back pain can be caused by herniation of the nucleus pulposus, the gelly inner part of the intervertebral disc. The nucleus then protrudes through the annulus, the outer fibrous ring, and compresses the nerves. If the annulus is still competent, replacing only the troublesome nucleus is a promising surgical option. A synthetic hydrogel is most suitable to replace the natural nucleus, since both are very rich in water. To assist the surgeon in correctly positioning the implant, we developed a biocompatible hydrogel that can be completely seen on X-ray images.

 

2. What has motivated you to conduct this work? 

Back pain is a major problem in our modern societies and to date there is no "perfect" solution. Also this research is very close to application, so you have to keep in mind the clinical relevance of your work. Therefore we collaborate with some orthopedic surgeons at the academic hospital, because they are the people that will have to use it in the future.

 

3. Where do you see this work developing in the future? 

The road to clinical application is still a long and winding one. Currently we are working on the biomechanical evaluation of the materials. The next step will be the implantation of our hydrogel nucleus replacement in a realistic animal model. The last step before clinical application will consist of a clinical trial.

 

4. Are there any particular challenges facing future research in this area? 

It is difficult to simulate the in vivo situation in a model system for testing the biomechanics of the implant. The natural nucleus and annulus (the fibrous ring) engage in a synergistic interaction, that determines the behavior of the intervertebral disc. 

This is virtually impossible to mimic in an experimental setup. Therefore it is a challenge to evaluate the material behavior and to translate that to the functionality of the implant in vivo. Also, though it might not be very elevating, it is a challenge to get the financial means to conduct the necessary animal experiments.