Intermountain Press Release

American Fork, Utah—One year ago Michael Callahan, M.D., an orthopedic surgeon in American Fork, performed a significant surgery - in fact, the first of its kind in Utah County. Using the Oxford® Unicompartmental Knee System, Dr. Callahan successfully carried out a partial knee replacement surgery.

Leading surgeons in Oxford, England, along with engineers at Biomet, headquartered in Warsaw, Indiana, developed the unicompartmental (partial) knee system, which was not available in the United States until last year. The Oxford Knee is the only FDA-approved Free Floating Meniscal Unicompartmental knee system available in the United States and has been utilized throughout Europe for more than two decades.

The most common reason for knee replacement is osteoarthritis, which is the breakdown of cartilage in one or more joints of the knee. Unlike total knee replacement, which involves the removal of all the knee joint surfaces, a unicompartmental knee replacement replaces only one side of the knee joint. It is typically used for patients who have osteoarthritis in limited parts of their knee.

Knee osteoarthritis usually occurs first in the inner side of the knee because this side sustains most of the weight. In healthy knees, the unicompartmental method allows the knee's outer compartment and all ligaments to remain intact. By retaining all of the knee's undamaged parts, the joint may bend better and function more naturally.

Dr. Callahan first learned of the Oxford Knee when Biomet invited him to a training meeting to learn more about the device and how to use it.

"I was impressed with the reports they shared from Great Britain and Europe over the past 20 years, so started to use it here at American Fork Hospital," said Callahan.

Once Dr. Callahan received the required training, he began to use the Oxford® Knee System in surgeries he performed at American Fork Hospital, becoming the first physician in Utah County to complete the procedure.

So what makes Biomet's unicompartmental knee system different? In a healthy knee, the meniscal cartilage serves as a shock absorber between the ends of the bones. The Oxford Knee is the first unicompartmental implant with an artificial meniscal bearing designed to glide freely throughout the knee's range of motion to more closely replicate normal movement. The free floating nature of the device also greatly improves durability of the implant.

According to Dr. Callahan, the most impressive feature of the knee system is "the motion and dynamics of the knee to be able to move and recover better." "We've had patients tell us it feels much closer to normal knee to them, rather than a mechanical knee."

Because the operation is performed through a small incision, The Oxford Knee also allows for a more rapid recovery and less extensive rehabilitation when compared to a standard total knee surgery, said Callahan. The surgery time is a little longer for the new procedure, but that is the only modification experienced in the Operating Room.

Since Dr. Callahan performed his first Oxford Knee surgery last year, he has completed more than 25 similar procedures with the component. Although the surgery is growing in popularity, only approximately 25-30 percent of Dr. Callahan's patients are good candidates for the Oxford Knee System. Those who do qualify should have normal interior ligaments, arthritis limited to inner side of the knee and must have no history of rheumatoid arthritis.

Surgeons in the U.S. who wish to use the Oxford System are required by the FDA to attend an advanced instructional course on the device.

Dr. Callahan has been in orthopedic surgery since 1975. He received his medical degree from George Washington University Medical School. For more information about this procedure, please contact Dr. Callahan at Central Utah Clinic, Orthopedic and Plastic Surgery, 763-3885.