As U.S. baby boomers age, it’s estimated the number of artificial joints needed to replace damaged knees will rise 673 percent to 3.5 million a year by 2030.

The study, by Steven M. Kurtz, of Exponent Inc., a Philadelphia-based engineering and scientific consulting firm, also found the demand for artificial hips is estimated to jump 174 percent over the same period to 572,000 a year, the Chicago Tribune reported Friday.

A generation ago, when artificial joints were not available, individuals that had joint problems were crippled, said Dr. Joshua J. Jacobs, associate chairman of orthopedic surgery at Rush University Medical Center, who was not involved in the study.

Now that these artificial joints are available, people can be returned to the workforce and returned to a higher quality of life.

Ninety percent of those getting an artificial knee replacement report pain relief, improved mobility and a better quality of life, according to a 2003 National Institutes of Health report.

The findings were presented Friday at the American Academy of Orthopaedic Surgeons’ annual meeting in Chicago.