The knee is one of the most surgically replaced joint in the body. The decision to replace your knee should be made in consultation with your orthopedic surgeon and your physical therapist. It is a pretty involved surgery, that could take a long time to rehab and will cause permanent changes to your body, so the decision should not be made lightly. Usually, indications that you may need a total knee replacement is when:
- You have extensive knee joint damage from knee joint diseases like osteoarthritis, rheumatoid arthritis, or a fracture through the joint.
- Severe knee pain or chronic misalignment of the knee causing severe disability with walking or performing everyday activities (such as the inability to walk to the bathroom).
If your knee pain is not as severe, you may benefit from conservative physical therapy first. There are a lot of cases of patients who have recovered very well from PT or have found that PT helped in delaying the need for extensive surgery. Read about knee pain physical therapy here.
What is a Knee Replacement?
A total knee replacement replaces the articulating parts of a knee joint. It involves removing the ends of the bones of the femur and tibia and replacing them with man-made caps, usually made out of plastic and titanium. Sometimes the surface of the kneecap is also replaced with a plastic surface.
Physical Therapy Can Help Pre-Operatively
Physical Therapy can improve strength and range of motion pre-operatively without placing undue pressure or pain the knee. Research shows that improving these impairments can significantly improve the surgical and rehab outcomes for after the replacement is made.
Furthermore, your physical therapist can show you how to walk with assistance after your surgery, and they will also discuss how to prepare for life after surgery - such as minor home adaptations and bathroom adaptations like getting a toilet seat riser, or strategically placing chairs where you need to stoop. This will make life a lot easier knowing the preparations beforehand.
Therapy After Your Surgery
Physical Therapy can actually begin very quickly after the surgery, typically within the same week of surgery. Your physical therapist will start off by introducing you to the basics: how to bear weight and use a walker/cane to ambulate, how to safely get in and out of a car, how to go up and down stairs or curbs. Inflammation control is vital in the early stages so the application of ice packs should be regular.
After this initial phase of healing, you and your physical therapist will get to work on improving range of motion of the knee. Your plan of care is tailor-made to suit your impairments, your lifestyle and your goals so strengthening and functional exercises also will be progressed according to your needs.
Balance training is also a very necessary part of the leg injury rehab program so you are fully prepared to take what life gives you in the future. Training can include agility exercises that involve quick stops and turns so you gain better knee control during these activities.
Knee Replacement FAQ
Following are some questions we commonly receive from patients who will or have undergone a total knee replacement.
- Improve knee joint mechanics by increasing flexibility and strength of the quadriceps for squat, step, and loading ability
- Strengthen gluteal muscles and ankle proprioception for limb and weight bearing stability
- Decrease inflammation through use of modalities and taping methods
If you have decided that a replacing your knee is something that is in your near future, it's best to be armed with as much knowledge as you can before you embark on your rehab journey. Your physician will probably go over the many things involved in the surgery, but below is guide strictly from the rehab perspective... coming from the rehab professionals ourselves.
Q: How long will the whole rehab process take?
A: It varies. The fastest I have rehabilitated a patient from a knee injury surgery to full functional walking, stairs and squatting is less than a month, but I have also had a handful of patients taking 2-3 months total. It depends very much on your body's ability to heal, your tendency to form scar tissue, and your compliance to the home exercises prescribed to you.
Q. How will I feel after the replacement?
A: A lot of patients will feel their usual arthritic knee pain disappear, however the pain is replaced by the soreness and scar tissue pain after the knee replacement surgery. Further down the rehab process, patients feel stronger and more limber, but you may not feel like you have a "normal knee" for a while, for up to a year after surgery. Some patients feel considerable numbness in the skin, a general feeling of fullness around the joint, and a lack of proprioception. But this all fades as patients use their knee more and more.
Q. What should I watch out for in the first few weeks after surgery?
A: You should definitely monitor your temperature. A fever is usually a sign of infection, so call your physician at the first signs of this. You should also call your physician if there is a foul smell emanating from the surgical wound and if there is excessive seepage.
You should also watch out for pockets of pain, extraordinary stiffness, heat and swelling in the calf and hamstring. This could hint to something serious like a blood clot and needs to be seen by a physician immediately. Also, report any signs of unusual shortness of breath.
Q. How early can I start Physical Therapy?
A: Most physicians prefer to wait a week before PT starts, but the earliest I have seen a patient in an outpatient setting after a Total Knee is the same day of the surgery. The prognosis seems to be a bit better for folks who get faster care - mostly because patients are educated on activities that avoid an accumulation of inflammation and scar tissue.
Q. Can I move around after the surgery? Or will I be debilitated for a while?
A: Some patients are comfortable weight-bearing and walking for a few feet the days after their surgery. This is very dependent on the patient's pain tolerance and general conditioning. Though if the patient prefers to stay off their feet for the first few days, continuous knee bending and hip movement while lying in bed is necessary to ensure preservation of range of motion and muscle strength. The worst thing for a patient to do is to not move. Conversely, too much movement could also be deleterious - I had a patient get so excited to not feel her arthritic pain that she walked the whole mall the day after her knee replacement surgery! Needless to say, I saw her the next day with a very hot, inflamed and painful knee. She did not damage anything - her progress was simply set back a week or two. The best guide is to give yourself continuous, easy movement (on a scale from 0-10 of physical exertion, you want to be no higher than a 4/10).
Driving may be difficult because of your limited knee range of motion. You should plan to have someone help you drive around for the first few weeks to a month after your knee replacement. Of course, you will be more affected by this if your surgical knee is your right knee.
Q. Speaking of range of motion, what is normal? I have heard nightmares about gaining range after a Total Knee.
A: Functional knee range of motion for bending should be about 120 degrees. Full straightening of the knee (0 degrees) is absolutely vital for gait mechanics. So avoid placing a pillow under the knee for sleeping comfort, this will cause scar tissue to form and impede your ability to straighten it. You can do it sparingly for comfort, but should not be kept in this position for longer than 15 minutes.
Strength in the hips, ankle and knee is vital to gain strength for stair climbing, walking endurance and sit-to-stand ability. But sometimes the most challenging part for the PT and the patient in Total Knee rehabilitation is gaining range. Scar tissue, once formed and solidified, is difficult breakdown. Unfortunately, everyone forms scar tissue at different speeds and at different level.
Q. What if I never gain the adequate range?
A. In this case, the physician may opt for a "manipulation under anaesthesia" where they bend and straighten the knee while the patient is drugged. There is no open surgery for this, but may prolong the rehab process a bit more afterward. We PT's want to avoid this at all costs, simply because it backpedals on the progress already made.
Q. Any other tips?
- Ice is your best friend. Do this often, about 3 times a day at first. Best done with a cryocuff (a compression sleeve with ice cold water running through it). Icing helps to calm down the inflammation.
- Once the surgical wound is closed, stitches/staples removed, maintain integrity of the skin over and around the scar tissue. Keep it moisturized and soft. I instruct patients to do scar tissue mobilizations on their own with Vitamin E oil or cocoa butter. The softer the skin around the wound, the better movement will be.
- Your bike will be your next best friend. If you don't have one at home, obtain access to one through a gym. Upright bikes are always best. It may be difficult to use in the first month, but diligent usage everyday helps with range, strength and inflammation control.
- At all costs, avoid being in one position for too long. If you are sitting, get up every half hour or hour and walk around the house. Stasis always makes inflammation worse, and puts you at higher risk for a blood clot.
- LISTEN TO YOUR PHYSICAL THERAPIST AND DO YOUR EXERCISES!
- If you have any further questions about medications after your total knee replacement, we advise you direct those to your physician.
Q. Last but not least, is getting a Total Knee Replacement worth it?
A. For some folks with very serious osteoarthritis, who come with a large number of functional limitations (unable to navigate stairs/steps, unable to walk across the street by the time the pedestrian light turns red) getting a total knee replacement are well worth it. If you do not fall in this category I recommend trying a bout of nonsurgical physical therapy to see if strengthening and posture retraining would delay or negate the need for one.