When it comes to joint repair and replacement, there are two different issues that have to be addressed. One is the replacement itself, the construct that replaces the bone involved. The other is the material that normally fills and cushions the joint. I’ve actually had exposure to two different efforts to address those issues, and one of the reasons I’ve held out this long is the hope that advances in both areas would be more readily available.
Let’s start with the replacements. Currently, these are often metal and solid metal, which is very unlike the structure of normal bone. Bone itself is very porous on the inside, with the outside being solid and relatively smooth. This can and does create problems when trying to mate two very dissimilar structures. The differences in mass and other factors can create fractures and other issues.
Many years back, a company was doing work through the Center for Commercial Applications of Combustion in Space (CCACS) at the Colorado School of Mines, on a advanced bone replacement materials. The immediate goal was to get the data needed to create foaming metallic-ceramic replacements that would have the porosity of normal bone as well as the hard surfaces needed for the ball or socket. The idea was to be able to custom make these in the OR, as since the reaction was exothermic they would be sterile at manufacture. The long-range goal was to create a material that would do the same, but as bone and marrow grew into it, the material would dissolve so that at the end of a given time you would have all new and healthy bone and the replacement, having completed its duties as a scaffold, would have passed from the body.
I do wish either or both were available today! Unfortunately, I seem to recall that the research ended with the loss of Columbia and have not been able to find out much since I started trying to research it.
Now, the tissue that fills the gap in the joint is somewhat the ‘Holy Grail’ as my surgeon and I discussed yesterday. Yes, we did discuss the advanced materials and the state of current research. When I was at Purdue, I had the honor of working with the legendary Leslie A. Geddes. Short version is that he and his team not only developed early astronaut physiological monitoring systems (portions of which are still in use today), but also pioneered the implantable medical device field and regenerative medicine. There’s a reason he was awarded the National Medal of Technology in 2006 and it’s well worth reading even a short biographical sketch on him.
I’ve been following regenerative medicine and wish it was just a little further along (and covered by insurance). Part of the problem for me is that the osteoarthritis has done a lot of damage, and there is very little “pad” left in the joint. The majority of the area has none, and I’m pretty much bone-on-bone movement now. There are a couple of different prospects for having the body generate new filler, but neither appear to be quite where I need them to be. Five years from now may be a different story. In fact, I tried volunteering for some studies both to buy time/get some relief and help advance that research. Still wish that would have worked out.
If anyone hears of related research efforts, let me know as I would like to know more about them.