The debate goes on—which is better, a partial knee replacement (UKR) or a total knee replacement (TKR). A study out of Oxford University in England comes down on the side of the partial knee surgery but with some concerns.
Researchers matched 25, 334 UKRs to 75, 996 TKRs on the basis of propensity score. They found that UKRs had worse implant survival both for revision and for revision and reoperation than did TKRs at eight years. However, mortality was significantly higher for TKRs at all time points than it was for UKRs.
According to the study, people who have a total knee replacement are twice as prone to blood clots, deep infection, or heart attack and are three times more likely to have a stroke than are partial-replacement recipients. Though risk of death following knee surgery is small, a patient is four times more likely to die within the first month of a total reconstruction and has a 15% greater chance of dying in the next eight years than is someone who has a partial operation.
“Total knee replacement is a bigger, longer operation with more blood loss, more bone resection, and significantly more damage to the soft-tissue envelope that surrounds the knee, ” said study co-author and surgeon Alexander Liddle, M.D. “The entire knee is exposed, and the ligaments have to be ‘balanced’ by releasing them at their insertions. This causes more blood loss, which puts strain on the heart, and makes blood clots more likely. This translates into a much higher rate of heart attack, stroke, and death after total knee replacement. We believe that the higher mortality rate is simply a reflection of the greater likelihood of complications that put stress on the body.”
Liddle added, “We already know that people recover more quickly, have better functional outcomes, are more likely to return to work or sports, and have a more ‘normal’ knee after partial knee replacement compared to total. This is probably because the anterior cruciate ligament (ACL), which is vital to normal knee function, is retained in partial knee replacement.
