A Mount Sinai School of Medicine study has found that patients often exhibit a significant decrease in weight and body mass index (BMI) after undergoing knee or hip replacement surgery (arthroplasty). The study is the first of its type to correct for the annual increase in BMI typically found in North Americans between the ages of 29-73 years of age. The study was recently published in Orthopedics.
A total of 196 Mount Sinai patients who had knee or hip replacement from 2005 to 2007 to treat osteoarthritis were randomly selected for the study. Mean patient age at surgery was 67.56 years of age, with about 65% female and 35% male. Of this group, 19.9% demonstrated a clinically significant decrease in weight (defined as the loss of 5% or more of body weight) and BMI following knee or hip replacement. In addition, the mean weight of the group dropped from 79.59 kg (175.47 lbs) to 78.13 kg (172.24 lbs) after surgery.
Significant BMI decrease was found to be greater in knee replacement patients (21.5%) than hip replacement patients (16.9%). Patients who were obese prior to surgery were the most likely to experience significant post-surgery weight reductions.
“Total joint arthroplasties are performed with the intent of relieving a patient’s pain and disability,” Michael Bronson, MD, the study’s lead author and chief of joint replacement surgery at Mount Sinai School of Medicine. “Both total knee patients and total hip patients experienced a statistically significant and clinically significant corrected weight loss following surgery, which indicates a healthier overall lifestyle.”
These results suggest that patients have improved weight parameters when compared to North American adults. Bronson and his joint replacement team at Mount Sinai believe that additional studies of total knee and total hip arthroplasty postoperative patients, which also incorporate nutritional guidance and long-term fitness goals, may show even more encouraging results.