Knee Replacements and Physical Therapy
Total knee arthroplasty or total knee replacement is becoming more and more common. It can be a life changing procedure that is very effective at reducing pain and the success rates of the procedure are very good. It is something that as a physical therapist, I really encourage those with severe osteoarthritis and knee pain that impairs their daily life to consider sooner rather than later. As with anything there are risks with any surgery and something that needs to be weighed between the patient and their surgeon, but overall, I often hear people wish they would have done it sooner.
The longer you go with knee pain (the kind that can make walking even difficult) the more strength you lose, the more function you lose, and typically the more motion you lose. All of those factors can make your rehab process a bit more difficult and longer. As is the case with most procedures, the better you go into it, the better you are coming out of it. I do think those with mild to moderate arthritis can benefit from physical therapy before electing to undergo surgery, but typically those with severe OA and high pain have difficulty even tolerating physical therapy (see last article on physical therapy and arthritis).
With that said, even though outcomes are generally successful, recovering from a total knee replacement can be very difficult, especially early on. For the first 2-4 weeks it is one of the more painful recoveries from an orthopedic surgery standpoint. At this stage in the recovery, most patients are dealing with a lot of pain and swelling. Managing both of these early on are some of the top priorities. Managing time on our feet early on can really have a positive impact on both of these. We want to move, but short and frequent, and never spend too much time on our feet at once. In this early stage we are focusing a lot of time on regaining the mobility (bending and straightening) of our knee. Your physical therapy will also have some early strengthening likely with a focus on restoring your quadriceps activation. Swelling in our knee tends to cause our quad muscle to be inhibited or “turned off”. The exercises at this stage are often low intensity and done frequently. Isometrics may be a good option here as well as the patient is in control of the load more and are often tolerated better early on.
It seems pretty consistent that about the 8-week mark people really start to turn a corner and note their pain to be better than pre-surgery levels. By this stage strength should be returning and you will likely be on a progressive resisted strengthening program. Swelling is a good guide to activity levels, but again you should be tolerating longer and longer durations on your feet. Getting back into a walking program can be very beneficial. Eary on after total knee replacement you want to avoid high impact activities.
Most physical therapy episodes following a total knee replacement last anywhere from 8-16 weeks depending on how quick the recovery goes and what the patients’ goals are and what type of activities they plan on returning to. By 12-16 weeks you are likely transitioning to more of a home exercise program and returning to most of your activities. For higher impact activities, I always recommend consulting with your surgeon to see what level they are comfortable with you returning to. I have seen patients get back to lifting weights, skiing, higher intensity hiking, and jogging (most surgeons would prefer you not to run but I have seen it multiple times). If you're having knee pain and have known arthritis, I think consulting with an orthopedic doctor and physical therapist is a good place to start and weigh your options from there.