Partial knee replacement may be possible when damage is limited to just one part of the knee but it isn't the best option in most cases and it's important to understand the limitations, especially for younger patients.
Carmel, NY (PRWEB) December 13, 2012
Knee replacement surgery has come a long way since it was first performed in 1968. More than 600,000 knee replacements are performed each year in the United States, according to the Agency for Healthcare Research and Quality, a division of the U.S. Department of Health and Human Services. Improvements in materials and advances in surgical techniques have led to better outcomes for patients: faster recovery, improved function and greater longevity. The majority of knee replacements are performed on people over the age of 60 but improved surgical results have induced many younger people to have the procedure sooner rather than later to reduce discomfort and enable active lives as they age.
“As new surgical procedures have been developed and refined, one that is sometimes offered as an alternative to total knee replacement is partial knee replacement, ” says Dr. Joel Buchalter of Somers Orthopaedic Surgery and Sports Medicine Group. “Partial knee replacement may be possible when damage is limited to just one part of the knee but it isn't the best option in most cases and it's important to understand the limitations, especially for younger patients.”
The knee, the largest joint in the body, acts as a hinge to provide motion where the thigh meets the lower leg. The thigh bone (femur) meets the large bone of the lower leg (tibia) at the knee joint, protected in the front by the kneecap (patella). The joint surfaces where these three bones touch are covered with cartilage, a smooth substance that cushions the bones and enables them to move easily. As a result of injury or the wear and tear of aging, the cartilage can soften and wear away, allowing the bones to rub against each other and causing osteoarthritis, the most common cause of chronic knee pain and disability. A study published by the Centers for Disease Control (CDC) reports that nearly half (46%) of American adults and 2/3 of obese adults will develop painful knee osteoarthritis at some point.
When the surface of the joint is worn away, walking and daily activities become difficult. Conservative measures such as weight loss, anti-inflammatory medication, braces, orthotics, steroid injections, and physical therapy are generally tried and may be effective. In many cases, however, non-surgical treatment fails to correct functional limitations and relieve progressive pain, leading people to consider knee replacement.
“In knee replacement surgery, we remove damaged cartilage and bone from the surface of the knee joint and replace it with a man-made surface of metal and plastic,” says Dr. Buchalter. “Resurfacing the damaged and worn surfaces of the knee can relieve pain and help the patient resume normal activities. Some patients whose knee damage is confined to just one part of the knee may be candidates for a partial knee replacement. But there are very few patients for whom a partial replacement will produce a better long-term outcome than a total knee replacement.”
The knee joint can be thought of as having three parts, or compartments -- the front, the inside and the outside. Most patients' arthritis involves more than one compartment and their only option is total knee replacement. But if all the damage is to a single compartment, a partial or “unicompartmental” replacement may be feasible. A partial replacement removes only the damaged area of cartilage, requiring a smaller incision and enabling a faster recovery than with a total knee replacement. The disadvantages of partial knee replacement are that pain relief is less predictable and, most important, that the replacement may be less durable and further surgery may be needed. The most frequent cause of additional surgery is the development or progression of arthritis in the remaining parts of the knee, which necessitates conversion to a total knee replacement, a surgical procedure that is more complex than an initial total replacement.
In addition to having damage limited to only one part of the knee, candidates for partial knee replacement are generally elderly, slender, and relatively sedentary. Further, patients with significant knee stiffness or ligament damage are not good candidates. “There are few patients that match the optimal profile for partial knee replacement,” says Dr. Buchalter. “And even in those that are eligible, the possibility of arthritis progressing in other parts of the knee raises the potential for future additional surgery. Most patients will have higher probability of a long-term successful outcome with total knee replacement, a proven procedure that has brought long-lasting relief to millions of people.”
Somers Orthopaedic Surgery and Sports Medicine Group, founded in 1988, is one of the most comprehensive and specialized practices in the region. http://www.somersortho.com
Joel S. Buchalter, M.D., F.A.A.O.S., F.A.C.S., a founding partner of Somers Orthopaedic, has been in practice since 1988.