How to Exercise After a Hip or Knee Joint Replacement

Bionic body parts are no longer reserved solely for sci-fi movie plots. The Mayo Clinic performed the first U.S. total hip implant surgery in 1969; an estimated 2.5 million Americans were living with hip implants as of 2010.

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The numbers are even higher for knee implants. After the first total knee replacement in 1971, approximately 4.7 million Americans were living with a total knee arthroplasty as of 2010, according to the Mayo Clinic.

In both types of joint replacement, the prevalence rises with each decade of life. Less than 0.1 percent of men and women have a hip or knee replaced prior to age 50. The numbers increase to 10 percent of women and 7 percent of men between the ages of 70 and 79 who undergo knee replacements. And approximately 4 percent of women and men within this same age group will have a total hip replacement.

The good news: If you're active prior to surgery, a joint replacement won't keep you sidelined for long. After you've recovered from the initial surgery and physical therapy, chances are good you'll be able to do nearly everything you did prior to the surgery if you take a few precautions.

For a hip replacement, you can expect a hospital stay of between one and four days, depending on your recovery time. Before you're discharged, you'll need to be able to get in and out of bed by yourself and perform several other tasks.

But although you'll be able to get around fairly quickly, "it takes about six to eight weeks for the implant to solidly embed in the bone and before you can go from physical therapy to exercising," says Dr. Kristin Oliver, sports medicine and regenerative orthopedic specialist at Bluetail Medical Group in Columbia, Mo.

"It varies depending on the person. Someone who's frail and in their 80s, for example, won't get back to their usual routine as soon as a younger person," Oliver says.

By six months post-surgery, you can pretty much do anything aside from high impact, high endurance activities, says Oliver. The type of implant makes a difference. People who undergo a hip replacement can get back to light jogging and doubles tennis faster than those who had a knee implant, Oliver says.

"A hip withstands a bit more load [resistance/weight] and plyometric [jump training], explosive movements than a knee," she continues.

"Hips can, however, pop out of the joint if you attempt an extreme movement such as deep squats," says Dr. Timothy Gibson, orthopedic surgeon and medical director of the MemorialCare Joint Replacement Center at Orange Coast Memorial Medical Center in Fountain Valley, Calif. "This is more likely to happen, as over time as it wears down and becomes unstable, although it occurs primarily with extreme positions."

Specific exercise recommendations include, first, getting the approval from your surgeon. Then, follow these guidelines when returning to activities post-hip surgery:

1. Focus on core strengthening
2. Never stretch through discomfort
3. Modify yoga poses as necessary (avoid extreme positions)
4. Increase activity gradually over six to 12 months, which is likely how long it will take to return to prior activities at a pre-surgery level
5. Do not push plyometric (explosive, jumping) activities past what the hip prostheses can take

"Keep in mind a hip replacement is a plastic component and wears out over time. They usually last about 20 years," Oliver says. "Unfortunately, there's no such thing as a high-impact hip replacement."

Knee replacements due to wear and tear of the joint and subsequent osteoarthritis typically happen after 65. "When I come across a younger patient, it's usually due to a torn ACL [anterior cruciate ligament] earlier in life," says Gibson. Knee replacements last between 15 and 20 years.

The protocol for knees is similar to that of hips, with a one to four-day hospital stay dependent on the ability of the person to get around. Overall, however, it takes longer for knees to heal.

"Knees require more physical therapy before you can go back to activities," Gibson says. For hip replacements, you're usually walking without a cane by six weeks, and by three months you're more active on a hip.

"It takes four to six months after a knee replacement before you feel you have your life back," he says. But unlike hips, knees are not usually in danger of popping out. "Hips have more restrictions than knees as far as performing extreme positions," Gibson says.

After you've completed physical therapy and are given the go-ahead to return to an exercise routine, modifications for exercising with a knee replacement include:

1. Avoid high-impact plyometrics such as box jumps, deep lunges
2. Avoid high-impact skiing, such as doing moguls
3. Never push through pain
4. Stay clear of high level endurance running sports, which can wear out the knee faster

You can be pretty active as far as walking, hiking, golfing and such, says Gibson.

"Keep in mind you have a piece of metal rubbing against a piece of plastic or a piece of ceramic. So you can wear out the joint faster — much like the tires on your car. Re-do surgeries are more complicated, so you want to do one and have it last as long as possible — ideally for the rest of your lifetime," says Gibson.