As she strolls along the Monterey shoreline, Joan Weaver is enjoying far more than the view.
"I thought, 'That's not possible, I'm not going to have a pain-free knee ever again,' but I do," said Weaver.
Weaver says she had been suffering severe pain in her left knee for more than a year. One option would have been a total knee replacement, but her surgeon, Dr. Richard Dauphine, suggested a less invasive approach -- a partial knee replacement, using a custom made cap designed to match the exact dimensions of the damaged area.
"If only part of the knee is hurt, it's a much bigger operation to replace all the knee," said Dauphine.
X-rays revealed most of the deterioration was on the inside edge of Weaver's left knee. To create the cap, Dauphine performed a 3-D MRI, which was then transmitted to a company called Conformis. Using sophisticated software, Conformis shapes, sizes and fabricates the replacement, along with custom jigs to help the surgeon attach it correctly.
"It fits exactly on the bone of that patient, and it's curved so this fits no one else," said Dauphine.
The manufacturer says the custom design results in a tighter, more efficient joint. But data is still being collected in an ongoing clinical trial. So, at this point, there is no evidence that the new technology gives patients better long-term outcomes than with competing ones.
Still, Dauphine says placing the smaller device using the prefabricated jig is much quicker, and produces less trauma than traditional knee replacements.
"With whole knee replacements, you always remove a ligament -- anterior or cruciate, and in many casese both. And with this technology, you don't remove any ligaments. So you can generally get normal motion back," said Dauphine.
Weaver says she was able to return to work full-time in about nine weeks, and she's looking forward to pushing her limits further.
"Getting back out there -- walking, hiking, do a little horseback riding -- things that I haven't been able to do," said Weaver.
These new replacements are typically covered by insurance, and because the surgery is less invasive, doctors say costs can actually be lower than some older technologies.
Written and produced by Tim Didion