As the prevalence of rheumatoid arthritis increases, so does the number of total hip replacements and knee replacements and their cost to the U.S medical system according to a study published in Arthritis Care & Research

Starting with one of the largest databases of hospital procedures available – the Nationwide Inpatient Sample (NIS) – researchers at the Florida International University identified joint replacement cases throughout the U.S. and analyzed increases in surgeries and costs between 1997 and 2004. 

Some key findings:   

* In 2004, approximately 431,485 primary knee replacements were performed – a 53 percent increase from the year 2000. Some 225,900 primary hip replacements were performed in the US – a 37 percent increase for the same period.

 * In 1997, about 60 percent of primary hip replacements and 69 percent of primary knee replacements were in people ages of 65 and 84. Among the middle-aged, the number of joint replacement surgeries increased excessively – 71 percent for hip replacements and 83 percent for knee replacements – in 2004.

* Between 1997 and 2004, hospital charges for joint replacements increased faster than the rate of inflation. The burden on private insurance more than tripled – from $1.1billion to $3 billion for hip replacements and from $1.46 billion to $4.64 billion for knee replacements.

* If current trends persist, nearly 600,000 hip replacements and 1.4 million knee replacements will be performed in the year 2015.

The authors say these findings point to the need for public health education to reduce the proportion of people who are overweight – a factor in osteoarthritis – and to manage arthritis at earlier stages and for the health-care community to prepare for the “upcoming demand of surgical loads and its economic burden on government and private insurance systems."