Getting back in the game after a hip or knee replacement

While many patients who undergo a hip or knee replacement may wish to return to athletic activity after surgery, they should know that they may be taking a risk with their new joint. A review of the latest data on athletic activity after joint replacement, published in the October 2008 issue of the Journal of Bone and Joint Surgery found that despite their wishes, patients generally reduce athletic activity after joint replacement.

Joint replacement  is considered by many to be one of the most successful medical innovations of the twentieth century. Hip and knee replacement operations, which are increasing in frequency, predictably relieve pain and improve function for patients with arthritic joints.

Pain relief, has been and continues to be, the primary reason patients consider joint replacement. However, as the "Boomer" generation ages, improved joint function is becoming a more frequent motivator for patients undergoing joint reconstruction.

"Baby Boomers have a lower tolerance for discomfort and disability if they are involved in athletics," says William L Healy, MD, an orthopaedic surgeon at Lahey Clinic in Burlington, Mass. "After joint replacement they often want to be able to keep up the same level of sporting activity that they enjoyed in the past."

However, there are still questions within the orthopaedic community concerning the degree to which athletic activity is safe after a hip or knee replacement. It has been determined that patients who participate in strenuous athletic activity after a joint replacement have:

• Increased stress placed on the reconstructed joint causing the new joint to wear out more quickly. This might be caused by activities such as running, tennis or basketball.
• Increased wear to the artificial materials such as metal, plastic, or ceramic which comprise the new joint. Athletic activity can cause small particles known as "wear debris" to get loose within the joint. The particles can cause fluid build up and pain.
• Increased stress where the implant is attached. This results in inflammation and fluid buildup. It can cause the artificial components to become loose, and a revision operation may be necessary.

Furthermore, implant wear has been shown to be related to how much the joint is used as opposed to the length of time the artificial joint has been in place. It is still not clear how much athletic activity should be reasonably allowed or recommended following total joint arthroplasty in order to promote durability and survival of the joint reconstruction.

The orthopaedic literature regarding sports and total joint replacement (also known as arthroplasty) is not extensive, and high-quality, objective, evidence-based information is lacking. Recommendations in the form of expert opinion are available from the Hip Society, Knee Society and the American Society of Hip and Knee Surgeons, but those recommendations are not a substitute for better clinical research.

"We need to keep in mind that surgeons and patients often assess the success of joint replacement differently," Dr Healy says. "Surgeons look at pain, function, and survivorship and whether the patient needed revision, while patients consider their pain and activity. If the joint allows them to play their favorite sport without pain, they may not be concerned about needing an additional surgery, in the future."

Patients who choose to play sports after joint replacement should train for their sport, build up back, hip and knee strength, and be aware of the potential risks of athletic activity after joint replacement.

(Source: The Journal of Bone and Joint Surgery: American Academy of Orthopaedic Surgeons: October 2008)