Today's News

Friday, March 2, 2001

'Ideal' body mass index doesn't mean better outcomes

A study of the outcomes of 333 consecutive cementless total knee arthroplasties does not support the hypothesis that patients with an "ideal" body mass index (BMI) will have better clinical outcomes than 'overweight' and/or 'obese' patients.

The study found that BMI did not effect clinical outcomes or survivorship of the prosthesis, said R. Barry Sorrells, MD, The Joint Replacement Clinic, Little Rock, Ark., coauthor of the study presented in scientific exhibit 33. The knee system, LCS® tricompartmental rotating platform, was used for the arthroplasties on 266 patients by Dr. Sorrells between February 1984 and December 1993. The average follow-up was eight years with a range of five to 15 years.

BMI categories are based on recommendations from the World Health Organization (WHO). Eighty knees were in the "ideal" BMI category, 145 were "overweight" and 108 were considered "obese." Statistical comparisons of the three BMI categories were made using the following outcomes: pain score, degrees of flexion and function score.

None of the BMI categories demonstrated statistically different outcomes, however, degree of flexion approached statistical significance ("ideal" = 116, "overweight" = 115, "obese" = 111). It is noteworthy, said Dr. Sorrells, that these same patients' degree of flexion was statistically different preoperatively. Survival analysis gave no indication of differences between device failure for the three BMI groups (11-year survival estimates were "ideal" = 92.6 percent, "overweight" = 93.8 percent, "obese" = 92.8 percent).

The study found that BMI did not effect clinical outcomes or survivorship of the prosthesis, said Dr. Sorrells. Jeffrey A. Murphy, MS, of DePuy, a Johnson and Johnson Company, also was coauthor.

Funding was provided by DePuy, a Johnson and Johnson Company.

Home
Previous Page
2001 Academy News March 2 Index C

Last modified 15/February/2001 by IS