The outcome of total knee arthroplasty in obese patients.
BACKGROUND
Evidence linking increased body weight to osteoarthritis of the knee and the high prevalence of obesity underscore the importance of defining the outcome of total knee arthroplasty in obese patients. The purpose of this study was to compare the clinical and radiographic results of total knee arthroplasties performed in obese patients with those of total knee arthroplasties performed in nonobese patients.


METHODS
Clinical and radiographic data on seventy-eight total knee arthroplasties in sixty-eight obese patients were compared with data on a matched group of nonobese patients. The analysis was also performed after stratification of the obese group for the degree of obesity. All patients had the same prosthesis. The clinical data that were analyzed included the Knee Society objective and functional scores, patellofemoral symptoms, activity level, and complications.


RESULTS
The percentage of knees with a Knee Society score of > or =80 points at an average of eighty months was 88% in the obese group, which was significantly lower than the 99% rate in the nonobese group at the same time. The morbidly obese subgroup had a significantly higher revision rate than did the nonobese group (p = 0.02).


CONCLUSIONS
The results of the present study suggest that any degree of obesity, defined as a body mass index of > or =30, has a negative effect on the outcome of total knee replacement.
Department of Orthopaedic Surgery, The Good Samaritan Hospital, Arthritis Division of Johns Hopkins University School of Medicine, 5601 Loch Raven Boulevard, Baltimore, MD 21115, USA.
Jared R H
JR
Foran
Michael A
MA
Mont
Gracia
G
Etienne
Lynne C
LC
Jones
David S
DS
Hungerford
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D020370:Osteoarthritis, Knee / Q000209:etiology / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome