I saw a patient in my office recently who posed a difficult problem. She was in her mid-thirties and had undergone three surgeries on each of her knees. She now presented with significant arthritis in both knees, and her pain limited her ability to run and play sports. She was frustrated and confused.
Bone-on-bone arthritis and pain that limits activities of daily living is a common clinical scenario for patients in their sixties and seventies. If traditional management of arthritis pain, such as anti-inflammatory medications, activity modification, use of assistive devices, etc., are no longer relieving pain, then joint replacement surgery is a logical decision. But is that decision as straightforward for our weekend warrior in her mid-thirties?
A recent article in the journal Sports Health reviewed the current literature regarding physical activity after total joint arthroplasty. Laura A. Vogel, BS et al. offered the current opinions and recommendations about what levels and types of activities are appropriate after joint replacement surgery.
For those of you not yet familiar with the pain of arthritis or the limitations on physical activity, let me explain some of the issues. Joint replacements are surgeries where the surgeons essentially replace worn out bone and cartilage from a joint with metal and plastic. The primary indication for these surgeries is pain, and they generally have good success in relieving it. In fact, in the United States alone, it is estimated that approximately 300,000 knee replacements are performed each year.
As the aging population has stayed or gotten more active in recent years, patients have sought not only pain relief but also increased function after joint replacement. The concern for surgeons is that increased activity could increase the loads on those components and subsequently increase their wear rates. While maintaining physical fitness and health is certainly desirable, does that activity potentially compromise the artificial joint?
Arguments against physical activity
Many surgeons who specialize in total joint arthroplasty only recommend activities and exercise that places low stresses on the joint, such as cycling and swimming. Repetitive impact activities, such as jogging, in theory lead to higher rates of premature wear and increased chances of needing revision surgery. These revision operations are often more complicated and medical riskier surgeries. Several studies in the literature do show higher rates of revision joint arthroplasty in patients with higher activity than low activity.
Arguments for activity
After surgery, patients should try to maintain an active lifestyle. Not only will physical activity maintain or improve their overall health, it can increase bone quality and subsequently improve fixation of the prosthesis and decrease the chance of loosening. And there are studies that do appear to demonstrate lower rates of loosening in active patients compared to inactive ones.
Take home points about exercise after joint replacement
What can physically active patients planning to undergo joint replacement (or maybe recently have undergone one) learn from this debate? Since I do not perform joint replacements myself, I asked H. Del Schutte, Jr., M.D., Associate Professor of Orthopaedic Surgery at the Medical University of South Carolina and joint replacement specialist, for his thoughts.
I asked him for his opinion on activity soon after surgery. “Recovery periods vary. There are some techniques that may lead to an earlier recovery, but most studies show that everyone is the same around 2-3 months, regardless of the surgical regimen. It takes between 6 and 8 weeks for the bone to grow in and the scar tissue to mature. Even so, most patients are allowed to put full weight on their extremity from the day of surgery. In hip replacement, it is important to let everything heal before you begin an aggressive therapy protocol. Most patients are advised to walk as tolerated. Unlike hip replacements, patients with knee replacements may not regain full motion without an early aggressive therapy protocol. There are essentially no activity restrictions afterwards,” Dr. Schutte explained.
As far as physical activity affecting wear rates, he offers his insights to both sides of the argument. “In regards to how active you can be after hip or knee replacement, remember this is a moving mechanical part which can and will wear like any other mechanical part. Currently the materials used as bearing surfaces in hip and knee replacements are strong enough that it is reasonable to expect up to a thirty- or forty-year life span for the implant. These implants are analogous to tires. The more you use them, the faster they will wear. The reason for routine x-ray monitoring of replacements is in part to evaluate the rate of wear. If this process is identified early on, only the bearing surface may need to be replaced instead of the whole implant. This is a much smaller surgery with a much lower complication rate.”
He does point out that the advances in materials and designs have improved patients’ chances of returning to sports and exercise. “With newer implants, it is reasonable that patients with hip replacements can return to full activity, including golf, jogging or running, doubles tennis and skiing. The same is true for knee replacement patients. There is concern among a special category of patients with hip implants – those with metal-on-metal bearing surfaces. In some cases, these implants have been associated with very aggressive and destructive wear patterns. It is essential that these implants be monitored regularly.”
Patients who have or soon will undergo joint replacement should discuss activity restrictions and concerns about certain forms of exercise after joint replacement. Activity recommendations can be tailored to specific patients based on age, medical conditions, type of prosthesis, athletic goals and desires, and other factors. Dr. Schutte concludes, “All in all, it is much better to be as active as possible with your new hip or knee replacement. The advantages to your overall health from increased activity far outweigh any concerns regarding wear.”