Once your knees go bad, you have precious few choices. Corrective surgery, complete knee replacement or just living with the pain are among your limited options.
But when one sufferer began his research into the process of knee replacement, he found a high-tech option made by a company called ConforMIS which uses a 3D printer to build a customized knee to precisely duplicate a patient's own, instead of using a one-size-fits all product.
ConforMIS takes a CT scan of a patient's knee as the starting point of the treatment and builds from the data.
Founded in 2004, ConforMIS is a privately held company that develops and commercializes medical devices for the treatment of osteoarthritis and joint damage. The technology is built around FDA-cleared partial and total knee replacement systems. Each one is "sized and shaped to match each patient's unique anatomy for the potential of a more natural feeling knee."
Patient-specific implants and instruments are used to complete the treatment. More than 375 patents and patent applications in the areas of manufacturing, image processing, patient-specific implant systems, patient-specific surgical techniques and patient-specific instrumentation have been granted for the technique.
The implants are made of cobalt chromium molybdenum, a standard metal used in orthopedic implants. Tibial and patellar inserts are made of ultra high molecular weight polyethylene (UHMWPE) or vitamin-infused UHMWPE.
According to ConforMIS, patients can often return to office work in two to three weeks following their procedures, but those with jobs requiring longer periods of standing might need more time to recover.
Orthopedic surgeon Dr. Michael Wertz, a doctor at Boulder Community and Avista hospitals, is using the cutting edge technology to rebuild run-down knees.
"What it comes down to in knee replacement is trying to reproduce normal motion," said Wertz. "If you have a better fit of an implant – and restore mechanical axis and get that to a very close tolerance of what is perfect – I think it's going to last longer and function better."
Wertz says that, according to his patients, the precision of the 3D printed knee replacement process means less pain is involved.
"People notice it. Their knees feel pretty good a little quicker than with an off-the-shelf knee. They get up and are walking on it right away," Wertz says.
In general, patients faced with the excruciating discomfort of bone-on-bone pain feel relief immediately after surgery.
The customization uses extremely precise cuts by a surgeon in the bone itself to attach the new knee, and customized "ijigs" are used to locate those cuts.
"The cuts match perfectly to the location you want them to be and the angle," Wertz says. "The biggest thing is it's done beforehand by computer. You know the alignment. They send you a surgical plan, how much to expect to take off each area of bone. You can double check after you have made the cuts by measuring the piece you are taking off."
Doctors say that insurance typically covers the cost of the surgery, except perhaps the cost of the CT scans.
"They truly do fit remarkably well. When you're putting them in surgically, they're amazingly congruent," he added.