I have been practicing physical therapy long enough to see patients return for rehab for a following a revision of their first joint replacement. The focus of this column is to present the “current wisdom” on joint replacement longevity. How long will it last? How active should I be? This is a hot topic for discussion in light of the fact that significantly more young people (under 65) are getting joint replacements in order to continue an active lifestyle. Jerry Langan, President and CEO of Goodwill Industries of Northeastern Pennsylvania, is a good example. Jerry had a serious knee injury while playing basketball in high school. Years later, severe osteoarthritis developed in his knee and he required a total knee replacement at age 48. Following the replacement, he continued to play basketball, softball and other activities. 13 years later, at age 61, Jerry had a revision of his 1st replacement. He states that he is grateful for the first replacement because it improved his quality of life. He feels that the second replacement will last longer because he is older and less active. This series of events is typical of many “baby boomers” that are having joint replacements at a much younger age.
Osteoarthritis is the number one reason people have knee pain leading to a joint replacement. It slowly develops in the weight-bearing joints, most commonly in the hip and knee, creating pain, stiffness, swelling and loss of function. There are many nonsurgical options such as: rest, weight loss, medication, physical therapy, steroid injections, and viscosupplementation injections. However, when conservative measures fail, surgical intervention, such as a joint replacement, becomes the next option. A total joint replacement uses a prosthesis to replace the end of the bone damaged from arthritis. These new metal and plastic surfaces in the joint allow pain free movement and function in the hip and knee. These procedures have been performed since the early 1970’s. The outcomes for active people continue to improve with advances in technology, prosthetic materials and new techniques. As a result, many active people are eager to use their new joint to continue their active lifestyle. The ability to remain active, while not compromising the integrity of the new joint, continues to be the source of some controversy. It will be the purpose of this column to review the literature and provide recommendations to safely return to activity without compromising the life expectancy of the implant.
According to the American Association of Hip and Knee Surgeons (AAHKS), patients 65 years old and younger will comprise more than 50 percent of the total hip replacements by 2011 and total knee replacements by 2016. Therefore, improving implant reliability and durability will be critical. Presently, 94% of total hip patients can expect the implant to last approximately 15 years with 7% of the patients requiring revision. Long term studies also find that 91% of total knee patients will have a 14 – 15 year implant life expectancy. Keep in mind that most of this data was collected from joint replacements in an older and less active patient population. Studies also show that implant longevity decreases with activity level, especially aggressive weight bearing and torsion activities such as running and singles tennis.
At the November 2008 meeting of the AAHKS, a survey of orthopedic surgeons regarding activity level following total joint replacement was presented. 95% of orthopedic surgeons who participated in the survey reported that they place little to no limitations on low-impact activities such as: golf, swimming, walking or biking on level surfaces, stair climbing and doubles tennis. However, high impact activities carried many restrictions in order to reduce complications and improve implant longevity. For example, the percentage of surgeons discouraging the following activities are: 71% jogging, 83% skiing, 49% singles tennis. Most surgeons permitted doubles tennis with restrictions (twice per month). It is important to note that none of the respondents reported that they could sight scientific evidence to support their restrictions and relied on clinical experience.
As younger patients have joint replacements and desire to continue their activity levels, further technological advances in surgery and implant materials will be necessary. The October 2008 issue of the Journal of Bone and Joint Surgery reported that “Patients who chose 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 a joint replacement.” The report further states that impact activities may compromise the durability of joint replacement and new age technology and techniques have not yet proven to improve durability. Additional long-term studies are needed to determine the effect of high level activities such as running, skiing and singles tennis on implant longevity to guide the younger implant recipient.
Visit your doctor regularly and listen to your body.