; however, these groups have an inactivity rate of 40 to 50 percent, which continues to increase. (7) Arthritis costs $128,000,000,000 a year, including $81,000,000,000 in direct costs (medical) and $47,000,000,000 in indirect costs (lost earnings). Each year, $309,000,000,000 in direct and indirect costs is lost due to disparities in osteoarthritis and musculoskeletal diseases. (8) Obesity and other chronic health conditions exacerbate the debilitating impact of arthritis, leading to inactivity, loss of independence, and a perpetual cycle of comorbid chronic conditions. (9) Sixty-one percent of arthritis sufferers are women, and women represent 64 percent of an estimated 43,000,000 annual visits to physicians’ offices and outpatient clinics where arthritis was the primary diagnosis. Women also represented 60 percent of approximately 1,000,000 hospitalizations that occurred in 2003 for which arthritis was the primary diagnosis. (10) Women ages 65 and older have up to 2½ times more disabilities than men of the same age. Higher rates of obesity and arthritis among this group explained up to 48 percent of the gender gap in disability, above all other common chronic health conditions. (11) The primary indication for total knee arthroplasty (referred to in this section as TKA ), also known as knee replacement, is relief of significant, disabling pain caused by severe arthritis. (12) Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to be more active. When you have a total knee replacement, the surgeon removes damaged cartilage and bone from the surface of your knee joint and replaces them with a man-made surface of metal and plastic. In a partial knee replacement, the surgeon only replaces one part of your knee joint. (13) Total hip replacement, also called total hip arthroplasty (referred to in this section as THA ), is used if your hip pain interferes with daily activities and more conservative treatments have not helped. Arthritis damage is the most