Stretching implant life

Bone is an active material, it responds to stresses and strains. But in the absence of straining, bone adjacent to implants can become unhealthy, contributing to loss of adhesion.

For implants to be successful and to last for a reasonable length of time, it is recommended that patients follow physical exercise regimes. But in cases where the patient is completely immobile or with very restricted mobility, this is not possible. In these cases, drugs are often administered that can have side effects.

Now, researcher Athina Markaki and her team are working on a therapy whereby controlled levels of mechanical strain could be induced directly in growing bone via the prosthesis itself.

The idea is that the implant should have a highly porous surface layer, made by bonding ferromagnetic fibres together, into which bone tissue growth would occur. During the post-operative period, the application of a magnetic field will then cause the fibre network to deform elastically, as individual fibres tend to align with the field. This will impose strains on the bone tissue as it grows into the fibre network.