Changes in body weight after total hip arthroplasty: short-term and long-term effects.
BACKGROUND
Elevated body weight is associated with hip osteoarthritis (OA) and subsequently with total hip arthroplasty (THA). Patients with hip OA who are overweight often mention their restricted mobility as a factor that thwarts their attempts to be physically active and lose weight. There is some evidence that THA increases physical activity, but none for losing body weight after THA.


OBJECTIVE
The purpose of this study was to analyze the short-term (1-year) and long-term (4.5-year) effects of a THA on body weight.


METHODS
This was an observational, multicenter cohort study.


METHODS
For the short-term effect, all patients (N=618) were analyzed; for the long-term effect, a random subgroup (n=100) was analyzed. Preoperative and postoperative body weight and height were self-reported. Patients were categorized according to their preoperative body mass index (BMI <25 kg/m(2)=normal weight, 25-30 kg/m(2)=overweight, >30 kg/m(2)=obese). Clinical relevancy was set at a minimum of 5% weight loss compared with baseline.


RESULTS
The mean age of the study group was 70 years (SD=8), 74% were women, and mean preoperative body mass was 79 kg (SD=14). One year after THA, a significant decrease in body weight of 1% and 3.4% occurred for the overweight and obese BMI categories, respectively. After 4.5 years, a significant decrease in body weight of 6.4% occurred for the obese BMI category.


CONCLUSIONS
Height and weight-and thus BMI-were self-reported.


CONCLUSIONS
Patients in the overweight and obese groups showed a decrease, albeit not clinically relevant, in body weight after 1 year. After 4.5 years, a decrease that was relevant clinically was observed in the patients who were obese. It can be concluded that no clinically relevant reduction of weight occurred after THA, except in the long term for patients who were obese.
Department of Orthopedic Surgery, University Medical Center Groningen, University of Groningen, PO Box 30 001 BB51, Groningen 9700 RB, the Netherlands. n.paans@umcg.nl
Nienke
N
Paans
Martin
M
Stevens
Robert
R
Wagenmakers
Jan
J
van Beveren
Klaas
K
van der Meer
Sjoerd K
SK
Bulstra
Inge
I
van den Akker-Scheek
D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D015992:Body Mass Index; D001835:Body Weight; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009765:Obesity / Q000628:therapy; D015207:Osteoarthritis, Hip / Q000601:surgery; D050177:Overweight / Q000628:therapy; D015431:Weight Loss