More than 15 million Americans have osteoarthritis in their knees, and about 600,000 of them could be helped by a partial knee replacement. The x ray demonstrates a normal knee on the left and an osteoarthritis knee on the right.
Osteoarthritis mostly affects cartilage, the hard slippery tissue that covers the ends of bones where they meet to form a joint. Healthy cartilage allows bones to glide over one another. It also absorbs energy from the shock of physical movement. In osteoarthritis, the surface layer of cartilage breaks down and wears away.
This allows bones under the cartilage to rub together, causing pain, swelling, and loss of motion of the joint. Over time, the joint may lose its normal shape. Also, small deposits of bone, called osteophytes or bone spurs, may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint space. This causes more pain and damage.
A new way to fix osteoarthritis of the knees that uses robots and computers is helping patients walk out of the hospital the same day of surgery. Biomedical engineers have developed a robotic arm to facilitate precise resurfacing of an osteoarthritis knee before replacing it. In order to do this, a 3-D image of the knee is generated to give surgeons detailed imaging and provide a live-action view of the knee during surgery. A stereo camera system constantly updates surgeons on the location of the diseased portion of the knee preventing the healthy parts of the knee from being touched. Visual alarms tell the surgeons when they are too close to healthy parts, and the robotic arm gives artificial resistance so the surgeon feels like he’s hit a wall. After the resurfacing is done, the implant is placed.
1. Fixing Damaged Knees. Discoveries and Breakthroughs Inside Science.
2. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS).
