We thank Drs. Gursu and Aydin for their interest in our article. The purpose of our study was not to implicate obesity as a cause of hip or knee arthrosis, but rather to determine the effect of unhealthy weight on the progression of the arthritic process. Large-scale population studies have suggested arthrosis of the hip or knee is found in as much as 55% of the population, with 7% of patients having severe disease and approximately 2% progressing to total joint replacement. Our investigations have suggested a strong cross-sectional relationship between rates of total hip and knee arthroplasties with increasing obesity classes. Our hypothesis has been obesity leads to more rapid progression of already damaged hips or knees, leading to increasing rates of joint arthroplasty. We believe our national study based on the Canadian population has clearly shown obesity increases the relative risk ratio for the need of total hip and total knee arthroplasties, with patients with arthritis of the knee having the greatest risk.

We also concur with Drs. Gursu and Aydin that additional research in this important field is warranted. Obesity is a worldwide health concern for its effect not only on hip and knee replacement rates but also on a myriad of other diseases.