Artificial joints often suffer from the flaw of wearing out quickly. A replacement hip may need to be replaced itself after as little as two years, a difficult and costly process. It is estimated that ten percent of joint replacement surgeries are operations to replace a previous replacement, called revision. Revisions are no less complicated than the original surgery, requiring the same two or three days of preparation and weeks or months of recovery. Revisions also expose the patient anew to the risks of joint replacement, such as damage to the nerves and bones around the site, or pain or limitations from poorly placed components, and can cost over $100,000 each time.
Now researchers at the University of Southampton in England have used new computer modeling techniques to allow surgeons to create joint replacements with longer lifespans. This may be the biggest advance in joint surgery since total knee replacement techniques were successfully developed and used 45 years ago. The first joint reconstruction surgery goes back to Europe in 1821, but most of the operations suffered from unsuitable materials. By the end of the 19th century, orthopedic surgeons were using ivory joints. The first successful joint replacement surgery in the United States was performed in 1891. Now with state-of-the-art materials available, the sticking point in improving the useful life of joints is in the fit—which is where computer design techniques come in.
The computer modeling is meant to replace human guesswork in fitting artificial joint components. Currently, surgeons must rely on experience and general understanding of what typical musculature looks like to fit replacement joints. By using computational modeling to determine the mechanics of the replacement, surgeons will be able to design custom-fitted components to exactly the patient’s needs. By using data derived from imaging and computer models of how the joints will function, arthroplastic technicians can create artificial joints that exactly support weakened anatomy, to optimize the lifespan of the joint. The procedure replaces human judgment with a patient-by-patient analysis of precisely what is needed.