Newswise — WINSTON-SALEM, N.C. – An active aging population is a good thing for society. It also keeps John Shields, M.D., very busy.

Shields, an orthopedic surgeon at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, specializes in hip and knee replacement surgery. In fact, they’re the only operations he does.

According to the American Academy of Orthopaedic Surgeons, 300,000 hip replacements and 600,000 knee replacements are performed annually in the United States. That's a sharp increase from a decade ago, but nothing compared to what is coming: The organization projects that 600,000 hip replacements and 3.5 million knee replacements will be done annually by the year 2030.

“Not only is the current older population more active, they’re not as willing as people once were to live in pain and tolerate it,” Shields said. “And the current technology for hip and knee replacements is simply better than it was years ago.”

For example, Shields said, the plastic component parts and surfaces of replacement hip and knee joints are stronger and more durable than ever.

As has always been the case, joint replacement surgery is the final option for people with severe joint pain. Advanced osteoarthritis – the most common cause of joint pain – is not reversible, so when nonsurgical treatments such as medications and physical therapy fail to relieve pain and permit normal movement, total joint replacement is generally the best available course.

In addition to having access to better prosthetic devices, orthopedic surgery centers such as Wake Forest Baptist’s employ vastly improved, less invasive surgical techniques.

“Four years ago, people were going home two to three days after a knee or a hip replacement,” Shields said. “Now they go home in one to two days, if not the same day. “We are providing better patient care and having better outcomes, and as a result patients are doing better and getting back home earlier.”

Brian Harwood and Steven Jokinen are among those patients.

In July, Harwood, 65, received a replacement hip at Wake Forest Baptist in the morning. He slept in his own bed that night, thanks to a minimally invasive technique that allowed him to regain his mobility within hours after undergoing surgery.

Harwood, a sports-minded retired Air Force veteran, decided to have his hip replaced after being diagnosed with avascular necrosis, a condition that caused bone tissue in his right hip to die because of poor blood supply. He knew it was serious when the pain forced him to give up racquetball and golf.

“They've come so far with hip replacement surgery,” said Harwood, who was working out at a suburban YMCA just days after his surgery. “I can't believe how fast I bounced back.”

Jokinen, 64, was active in sports for years, playing basketball and running 30 to 40 miles a week while working as a carpenter for the city of Winston-Salem, a job that kept him on his feet constantly. But both his legs had become extremely bowed, a condition caused by a lack of cartilage around the knees, and he said he finally decided it was time for replacement surgery when he was in constant pain and unable to sleep at night, despite taking pain medications.

Only hours after the surgery on his right knee in January, Jokinen said, he startled Shields by flexing his legs before being asked to do so. Jokinen was walking on the leg the next day and back at work within a few weeks.

“I had basically gritted it out for years,” he said. “In hindsight, I would have done it sooner if I knew I would get the result I got.”

Jokinen’s left knee was replaced in September. With two new knees, his legs are no longer bowed. Like Harwood with his new hip, Jokinen is looking forward to a more active future.

“I fully intend to do some hiking and stuff I haven't been able to do in the last 10 years,” he said.

Before his operation in September, Jokinen enrolled in a clinical trial at Wake Forest Baptist designed specifically for people about to undergo knee replacement surgery.

Jokinen spent time five days a week for several weeks in an aquatic “prehabilitation” program in the pool at Wake Forest Baptist's Sticht Center on Aging. There he performed 60 repetitions of 45 different leg exercises over the course of each 90-minute session.

“This clinical trial is a follow-up to an earlier Wake Forest Baptist study that indicated patients with poor mobility who had major surgery had longer lengths of stay, more complications and were more likely to spend time in a nursing facility following discharge,” said the study’s principal investigator, Sunghye Kim, M.D., an internal medicine physician at Wake Forest Baptist.

It’s an especially bad problem for knee patients, Kim said, because their long-term pain typically keeps them from engaging in physical activity. As a result, they’re typically less fit when they undergo replacement surgery, she said.

The study is ongoing so it’s too soon for conclusions, Kim said, but early indications are promising. Jokinen is a big supporter of the “prehab” program.

“The idea of strengthening the muscles around the knee joint so they are as strong as possible when you come out of surgery is a philosophy that immediately made sense to me,” he said. “The leg feels solid as a rock; I can feel the muscles really tight, like they used to be.”