TKA Patients Gain More Weight Post-Op Compared to Healthy Controls
BY LAUREN UZDIENSKI, FEBRUARY 23, 2010
Despite the increased mobility associated with total knee replacement, a new study found that TKA patients actually gain more weight post-operatively than non-surgical controls.
The study, published in Osteoarthritis and Cartilage, enrolled 106 TKA patients and 31 non-surgical controls. The researchers recorded height, weight, quadriceps strength and self-reported functional ability at the TKA patients' first physical therapy visit following the surgery and again two years later. The study found that the TKA cohort not only started heavier than the controls, they were heavier two years later as well. Despite some weight loss in the first couple of weeks post-op, 66% of TKA patients went on to gain weight - 14 pounds, on average.
The authors concluded that this weight gain was independent of the effects of aging and was not related to education, marital status, income level and activity level prior to surgery.
These results suggest that functional improvement alone won't lead to greater fitness, and the authors recommend nutrition or weight management counseling in addition to the medical services associated with a TKA. The paper also makes a subtle case against delaying surgery in cases where intervention is needed, because as OA progresses, patients lose strength and fall out of the habit of moving around. In comments to Science Daily, study author Dr. Lynn Snyder-Mackler says that "functional level going into surgery typically dictates functional level after surgery" and adds that patients often don't take advantage of the functional gains they do experience. She suggests that these outcomes that may be altered by re-training patients to walk with their new knee and to incorporate physical activity into their lives.
Weight gain post-TKA is particularly problematic because it can compromise the patient's other knee; Dr. Snyder-Mackler says that 35-50% of TKA patients go on to have the procedure on the other side within 10 years.
