August 17, 2011
The end of Metal, Plastic and Ceramic Joint Replacements may not be as far-fetched as once thought. I’m pretty sure this is not happy news for the manufacturers of orthopedic devices… which play in a market valued in the Billions.
According to a recent article in the USA TODAY, in a decade or so, people now receiving metal and ceramic replacement joints may instead be able to have a fully functional biological replacement — a joint grown within their own bodies to their specific physiology.
To date, researchers have successfully grown replacement shoulder joints in rabbits, using an implanted biological “scaffold” upon which new cartilage developed, according to a study reported in The Lancet.
The new process works by implanting in the damaged joint what’s called a bioscaffold, which has been infused with a medication known as transforming growth factor beta-3. The drug encourages the body’s own cells — stem cells included — to become cartilage and bone cells.
The scaffold is made from polycaprolactone, a biodegradable plastic, and hydroxyapatite, a naturally occurring mineral found in bone and teeth.
Researchers removed the entire humeral head — the ball part of ball-and-socket shoulder joints — from rabbits used as test subjects and then implanted the scaffolds to grow a biological replacement for the missing piece.
The study reported that the rabbits implanted with the drug-infused scaffolds were able to use the joints and support themselves with them faster and more consistently than rabbits not given the scaffolds. After four months, a new cartilage surface for the humeral head had grown in place, with no complications or adverse effects. Researchers have been able to demonstrate that using a specific type of scaffold that’s been doped with a specific type of growth factor, cells will basically populate the scaffold and create cartilage.
(Dr. Thomas A. Einhorn, chairman of orthopaedic surgery and a professor of orthopaedics, biochemistry and biomedical engineering at Boston University and a spokesman for the American Academy of Orthopaedic Surgeons and Dr. James L. Cook, a veterinarian and director of the Comparative Orthopaedic Laboratory at the University of Missouri, and a member of the research team.)