Issue: November 2015
November 05, 2015
12 min read

Recommendations for patient activity after knee replacement vary among surgeons

Issue: November 2015
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During recovery after knee replacement surgery, exercise is critical. After initial recovery, patients will want to resume more strenuous activities. In addition to exercise prescribed by a physical therapist, several studies have shown patients who participated in athletic activities prior to surgery will want to continue this practice after surgery. However, how much activity and how strenuous this activity should be remains unclear.

“We just have [our] gut instinct as to what is best for the implant and what is not,” Richard Iorio, MD, told Orthopedics Today. “In general, if it feels comfortable with the patient, if they are educated and trained well in the activity and they can do it without pain or discomfort and it is good for their cardiovascular fitness, we will encourage participation.”

A literature review by Michael R. Bloomfield, MD, and his colleagues showed total joint procedures “are increasingly being performed in more active patients,” with 19% of patients returning to athletic activities after knee replacement. However, other research has shown there is limited peer-reviewed information to help orthopedic surgeons advise their patients on the appropriate athletic activity after knee replacement.

“There has always been a philosophy that the patient and the surgeon want the joint replacement to last as long as possible — hopefully, for the duration of the patient’s life,” Thomas P. Schmalzried, MD, told Orthopedics Today. “But that is in contrast to the philosophy about patients having joint replacement surgery to enjoy a better quality of life and there are certain physical activities that increase their quality of life. There is a big controversy about advisability as compared with capability.”

Low vs. high impact

Iorio noted surgeons will recommend against activities that have a high risk of falls or injury to the implant. Mary I. O’Connor, MD, noted that when it comes to return to sports activities, she strongly recommends her patients avoid running and jumping as part of their exercise routine.

Richard Iorio, MD
Richard Iorio, MD, noted physicians will encourage patient participation in activities after total knee replacement as long as patients are educated about the consequences of the activity on survivorship of their total knee arthroplasty, are trained well in the activity and can perform related tasks without pain or discomfort.

Image: Frank Martucci, NYU Langone Hospital for Joint Diseases

“I strongly encourage my joint replacement patients to do low-impact exercises, such as walking, biking, swimming, use of the elliptical and to do weight training with lower weight/higher reps. Keeping muscles strong is essential to promoting function and battling the sarcopenia, which occurs with age,” O’Connor told Orthopedics Today. “I still like patients to avoid running and jumping, as I do not believe implants were designed for these high-impact activities.”

According to The Knee Society, appropriate activities for patients following joint replacement surgery include cycling, calisthenics, swimming, low-resistance rowing, walking, hiking, low-resistance weightlifting and use of stationary skiing machines. Other suitable activities include bowling, croquet, golf, doubles tennis, table tennis and ballroom and square dancing. According to The Knee Society, activities such as downhill skiing, scuba diving, in-line skating, ice skating, softball, volleyball, speed walking, horseback riding, hunting and low-impact aerobics are suitable, but include more risk. Baseball, basketball, football, hockey, soccer, gymnastics, jogging, rock climbing, hang gliding, parachuting and high-impact aerobics are activities that should be avoided.

“We are now much more liberal with what we allow [patients] to do. We tell patients to avoid high-impact activities that could damage the implant, so generally running and jumping are not encouraged,” Iorio said. “That does not mean that patients are unable to do the activity it. It is just that we do not think it is a good idea for the long-term survivorship of the implant.”


However, recommendations to patients on appropriate athletic activity can range between surgeons. In a presentation at the Current Concepts in Joint Replacement Annual Spring Meeting earlier this year, Schmalzried noted differences in recommendations provided to patients from surgeons. Higher-volume surgeons, especially those doing a higher volume of revision surgeries, tend to recommend higher activity levels.

Schmalzried also noted in his presentation that most surgeons will allow patients to play golf after total knee surgery, but do not recommend running even though patients place as much load on their front leg during a full golf swing as they place on their legs when running.

“I understand there is a difference in frequency here, but in terms of the peak stress, there is no difference in the peak stress,” he said in his presentation. “It makes me think that if the peak stress is tolerable, then maybe, you should be able to run. On the contrary, if it was not tolerated, we should see a lot of loose hips and knees on the left side of right-handed golfers, and we do not.”

Thomas P. Schmalzried
Thomas P. Schmalzried


Although previous studies have shown staying active following knee replacement can be beneficial to patients, Jason C. Ho, MD, noted performing high-impact activities may cause wear of the implant.

“Data has shown with prior generations of polyethylene that the more you use it, the more it wears. This may or may not be true for current generation of polyethylene, as the evidence is still developing for long-term follow-up,” Ho told Orthopedics Today.

According to Iorio, “the bearing surface of the implant can generate wear debris,” which can cause pain, bone loss, loosening and subsequent failure of the implant. However, Ho noted there is little data showing that low-impact physical activities are harmful to the implant.

“The benefits of low-impact physical activity probably outweigh any risks, although there is no published data specifically supporting this statement,” Ho said. “In addition, a major reason to do surgery is to get patients back to an active lifestyle. If patients were going to sit on their couch all day and be sedentary, they probably would not need surgery.”

While the American Association of Hip and Knee Surgeons has previously published consensus guidelines based on expert opinion about the topic, Ho noted there are no specific guidelines for surgeons to follow with regard to activity following knee replacement.

“There is a wide variation on physician recommendations on activity postoperatively as there is scant literature on a large scale documenting what specific activities may adversely affect the longevity of implants,” Ho said. “Guidelines are always helpful to start a discussion; however, well-designed literature needs to be conducted answering specific questions on a large scale before useful guidelines can be made.”

“The main concept here is common sense, as well as an understanding that some patients may be willing to take a little more risk of revision because the activities they wish to participate in are meaningful to them and they are willing to accept that risk,” Iorio said. “As long as it is done with appropriate education, it is probably okay.”

Patient factors

According to the American Academy of Orthopaedic Surgeons, total knee replacement surgery has no age or weight restrictions. Similarly, age is not a cut-off for whether patients can participate in sport activities following the surgery.

“General advice regarding sports and return to activity is given to all arthroplasty patients regardless of age,” Ho said. “As many of us have seen in practice, chronologic age is not necessarily indicative of ‘physiologic’ age.”

Ho noted an important factor in return to activity following knee replacement surgery is whether the patient was physically active prior to surgery. A literature review by Alexander Golant, MD, and his colleagues showed 65% of patients who participated in athletics prior to total knee arthroplasty (TKA) returned to sports following surgery compared with no patients who were sedentary preoperatively. Patients who participated in athletic activity 1 year prior to surgery had a higher return to sports rate following TKA. The review also showed studies found an increase in low-impact activities and a decrease in high-impact activities following surgery.


“We counsel patients that pre-arthroplasty participation is a fair predictor of ability post-arthroplasty,” Ho said. “Just because patients can do something, does not always mean they should.”

In contrast to age, a high BMI may cause problems with patients returning to activity, according to Schmalzried.

Mary I. O’Connor
Mary I. O’Connor

“An index of obesity has a strong influence, not just on how quickly [patients] return to activities, but what their ultimate activity level is,” Schmalzried said. “It turns out BMI is a better predictor of postop activity than age.”

Two studies published in 2012 showed patient-reported outcome measures were similar among patients regardless of BMI. However, O’Connor noted obesity can have an effect on a patient’s functional activity following knee replacement.

“Obesity is a major problem and clearly limits patient’s functional activities both prior to and following joint replacement,” O’Connor said.

Ho also noted a higher BMI has been shown to be an independent risk factor for lower patient-reported outcomes and is a potential risk factor for increased polyethylene wear.

Despite the impact a higher BMI can have on a patient returning to activity following knee replacement, Daniel J. Berry, MD, noted return to activity recommendations are no different for patients who are obese.

“Of course, if someone is obese, we encourage them to be doing aerobic activities, which could be helpful in terms of managing the obesity,” Berry told Orthopedics Today. “But in terms of our recommendations for activity, we do not have any specifically different recommendations for somebody who is heavier than somebody who is lighter.”

Berry added there are other factors that come in to play regarding patients’ return to activity following surgery.

“Some [factors] simply relate to [patients’] overall level of health and their capability for activity, their aerobic health if you will,” he said. “Some of it relates to their muscle strength; some of it relates to their own psyche, that is, ‘Do they want to return to a high level of activity?’ Then, of course, there is the reality of how their joint replacement turns out in terms of how active they can be on the joint. Does it feel stable to them? Is it painless when they are active?”

UKA and revision TKA

Studies also have shown positive results for return to activity following unicompartmental knee arthroplasty (UKA). In a recently published study by Ho and his colleagues, clinical evaluation showed no difference in the number of UKA and TKA patients who returned to sports or their satisfaction. However, patients who underwent UKA returned to sports more quickly and had better postoperative knee scores, according to the study results.

“We did find [UKA] patients tend to return to sports activity sooner and have higher postoperative functional scores when compared with TKA patients,” Ho said. “However, the percentage that returned was no different, and the UKA patients also tended to have higher pre-arthroplasty functional scores.”

However, Berry noted since patients who undergo UKA are still protecting the bone-prosthesis interfaces and polyethylene bearing, they still have limitations similar to patients who undergo TKA.

“Some patients [can] manage a fairly high activity level, but our recommendations in terms of what activity they return to are roughly the same, and the reason for that is unicompartmental knee arthroplasty still has the same materials limitations as a total knee arthroplasty,” Berry said.

However, he noted that since patients who undergo UKA are still protecting the bone interfacing and polyethylene bearing, they still have limitations similar to patients who undergo TKA.

“Some patients [can] manage a fairly high activity level, but our recommendations in terms of what activity they return to are roughly the same, and the reason for that is unicompartmental knee arthroplasty still has the same limitations as a total knee arthroplasty,” Berry said.

“If someone is having a revision operation, they have already had a failure of their implant and they need to be a little bit more cautious with their activities after reoperation,” Iorio said. “Generally after revision, they are not going to have the same functional capabilities as when they had their first operation, but we are not going to restrict their activity any more than we did after the original joint replacement unless there are clinical circumstances, such as instability or bone loss, that warrant more caution.”


Berry noted patient recommendations also will depend on the severity of the revision surgery.

“In general, somebody who has had a major revision surgery, particularly if they have had a lot of bone loss or bone reconstruction, we tell them to be a little bit more on the cautious side simply because they are in a situation where they are at a greater risk — if they should fail — to start getting a problem that is more and more difficult to solve,” Berry said.

O’Connor highlighted that recommendations should be made on an individual basis, regardless of procedure or patient age.

“Sometimes recommendations are changed depending on the patient,” O’Connor said. “If there is a big, difficult revision where I had to do a lot of bone grafting, then I might recommend limited activity and a longer period of protected weight-bearing for a few months after surgery. But in general, I encourage a patients to return to their normal activities as soon as possible and I try to keep the instructions consistent and straightforward because it is easier for the patient and it is easier for my staff.” – by Casey Tingle

Disclosures: Berry reports he receives royalties on select knee implants from DePuy, is chair of the board of directors of the American Joint Replacement Registry, is a member of the board of trustees of the Journal of Bone and Joint Surgery and receives royalties from Elsevier and Wolter Kluwer for books he has edited. O’Connor reports she is a health care disparity consultant for Zimmer. Ho, Iorio and Schmalzried report no relevant financial disclosures.


Should there be postoperative activity restrictions following knee replacement?


Return to sport possible

Activity after knee replacement should be encouraged. Taking a holistic approach to the treatment of knee arthritis and population health, one can argue the most important benefit derived from knee replacement is the restoration of knee function, which allows patients to return to the workplace and have an active lifestyle.

Thomas Parker Vail
Thomas Parker Vail

When surveyed during the past 2 decades, knee arthroplasty specialists have reflected a high degree of variability in recommending activity after surgery, with some surgeons recommending no restrictions and others recommending avoidance of “high impact activity.”

Despite this equivocation from the surgeon community, the definition of allowable activity has been expanded by virtue of what patients choose to do after surgery. While most patients seek the ability to perform activities of daily living in comfort after knee surgery, many are also engaged in high-performance activity.

Strong evidence does not exist to draw the conclusion that high activity contributes to a higher rate of revision surgery. It should be noted that infection and aseptic loosening are the major causes of total knee revision surgery. Also, younger patients have a higher revision rate after total knee replacement (TKR) than older patients. While activity may play a role in aseptic loosening in some extreme cases; technical factors prior surgery, prior trauma and comorbidity play a much bigger role in overall outcome. A successful TKR does not guarantee the ability to perform physically at a high level, but does make high performance possible when an arthritic knee is the limiting factor.

Thomas Parker Vail, MD, is the James L. Young Professor and chairman in the Department of Orthopaedic Surgery at the University of California, San Francisco.
Disclosure: Vail reports he receives royalties from DePuy for certain hip and knee products; is the president of the Knee Society; is a director on the American Board of Orthopaedic Surgery, and has served on the boards of The Knee Society, The Hip Society and the American Association of Hip and Knee Surgeons.


Find balance

The primary objective of total joint arthroplasty is to restore patient quality of life through return of function and relief of pain. With the increasing prevalence of joint replacement, patients more commonly desire a return to higher levels of function, which often include sports. Despite the recommendations of orthopedic surgeons against high-impact sports and manual labor, it is clear many patients continue to engage in a variety of sports activities.

Michael L. Parks
Michael L. Parks

Activity guidelines after total joint replacement discouraging high levels of impact are designed to prevent premature implant failure from multiple factors including bearing wear, implant failure or failure of fixation. Repetitive high-impact athletic activities raise a significant concern for the long-term risk of requiring revision surgery when compared with less active patients.

Patients must balance their desire for activity with implant longevity. Despite significant improvements in knee replacement, including ceramic coatings, mobile-bearing replacements and high-flexion implants; bearing surface wear and loosening are still primary modes of implant failure. The potential benefits of these innovations have not been proven with long-term clinical trials. We must advise our patients who play sports after TKR of the relative risks to allow them to carefully assess the benefits of satisfaction from athletic participation vs. the risk of potential reduced survival of their joint implant.

Michael L. Parks, MD, is an associate attending surgeon in the Adult Reconstruction and Joint Replacement Division at Hospital for Special Surgery in New York City.
Disclosure: Parks reports he is a consultant for Zimmer.