It may make common sense that the pain relief gained through knee replacement surgery would instigate more physical exercise and, thereby, better weight control. 
But that is not what researchers found when they tracked 106 patients for two years following their knee replacements. Instead, 66 percent of the subjects had gained an average of 14 pounds.
The good news is that the other one-third had lost, on average, approximately four pounds. In those who lost weight, no decline in quadriceps strength was seen, whereas the quadriceps had weakened in those who gained weight.
Researchers explained that, after surgery, single knee replacement patients have a tendency to place more weight on the knee that wasn’t replaced. The added load of weight gain can compromise both knees and, in particular, may hasten the progression of osteoarthritis in the non-operated joint.
In summary, knee replacement patients should take care to maintain a healthy body weight. If knee pain persists following the surgery, such patients may wish to consider swimming, pool aerobics or other joint-sparing workouts designed to control weight and promote heart health.
This research was conducted at the University of Delaware. Click here to read the university’s report on the study.
For elderly patients a knee replacement may do more than reduce the pain associated with osteoarthritis of the knee, according to a study described at the annual meeting of the American Academy of Orthopaedic Surgeons in March. A new knee joint may also improve balance.
