[What effect does of obesity have on the outcome of total hip and knee arthroplasty. Review of the literature].

As the prevalence of obesity worldwide continues to rise, defining the relationship between obesity and arthroplasty outcomes becomes increasingly important. The effect of obesity on the outcome of total hip or knee arthroplasty has been reported to be variable. Some authors believe that a high body weight will lead to less than optimal arthroplasty outcomes, because increased body weight leads to increased stress across the components and an increased load on the surrounding bone. Although this should, in turn, lead to a higher incidence of aseptic loosening or prosthetic failure in obese patients, studies have suggested that the effect of increased body weight and arthroplasty outcome are not so straightforward. The lower activity level typically observed in obese patients may partially counter the negative effects of increased weight on the bone-prosthesis interface. Although results do not show significant differences in all studies, it appears that obesity has negative impact on the results of total hip and knee arthroplasty. Therefore, long-term studies using large sample sizes should be conducted. If significant differences are demonstrated, an altered course of treatment, such as having a patient lose weight before considering a total hip or knee arthroplasty, might be advocated.