Permanent Joint implants - Yes its without an expiry date!

Artificial joints presently come with a limited lifespan.  With wear and tear of these implants after few years from transplant many hip and knee joints have to be replaced. The situations become more complex when we talk about wear and tear of intervertebral disc implants, which cannot easily be replaced after their "expiry date". This restricts the patient's freedom of movement considerably.
Dr. Kerstin Thorwarth and team at Nanoscale Materials Science at Empa technology have devised a coating made of DLC ("diamond-like carbon") on mobile intervertebral disc implants so that they show no wear and will now last for a lifetime.

Normally a standard procedure of artificial joint replacements can be repeated up to three times with most implants.  As bone material is lost each time an implant is explanted, the new joint has to replace more bone and is therefore larger. In the case of intervertebral discs, this is virtually impossible. They are too close to spinal nerves and tissue structures that could be damaged by another operation. Currently available product implants carry the risk of triggering allergies or rejection reactions due to material abrasion.

These abrasions are actually caused by the corrosion behaviour of the bonding agent between the DLC layer and the metal body. This layer was made of silicon which corroded over the years, causing it to flake, which led to increased abrasion and, as a result, bone loss.

Empa researcher finally found and tantalum to be used as the bonding agent.  This coating was tested in a so-called total disc replacement - a mobile disc implant. They simulated 100 million cycles, i.e. about 100 years of movement in a specially designed joint simulator.  The small intervertebral disc implant held out, remaining fully operational with no abrasion or corrosion. The new bonding agent will be used in combination with DLC coatings for other joints too in near future.

Specific Implications for PTs -

Physiotherapist plays a major role in rehabilitation post joint transplant, where we see patients dealing with a new joint. Some patients recover within weeks, some take months to years.
If the same process of joint transplant is repeated after five to ten years, the patient may find it difficult to rehabilitate fully as aging leave its mark on body. The healing capacity as well as functioning reduces with age, hence this permanent joints will help patients to recover once from the agony of transplant. Knowledge about provision of such implants is essential for the benefit of the patients.

Joint implants without an expiry date from Empa technology

New Coating May Finally Help Make Artificial Joints Last a Lifetime.