AFTER TOTAL KNEE REPLACEMENT
This rehabilitation program is not fixed in stone and may be adapted depending on intra-operative findings, occurrences and results.
I always, tell my patient’s that after a knee replacement they will feel a lot more discomfort than for a total hip replacement.
If no problems arise, you will begin with physiotherapy the morning after surgery. Sometimes we will use continuous passive motion machines that move the leg immediately after surgery. You will work with physical therapy until you meet the following goals:
- Independent in getting in and out of bed.
- Independent in walking with crutches or walker on a level surface.
- Independent in walking up and down a flight of stairs.
- Managing to go to toilet and get up from a chair.
- Independent in your home exercise program.
Your knee replacement will have the ability to take your full weight but crutches are used for support, protection of the stitches and pain relief in the first 3 to 6 weeks. Immediately the day after surgery the physiotherapist will begin with exercises to encourage movement of the knee. It is my usual protocol to place your leg in a continuous passive motion machine the day of surgery in order to encourage early range of motion. You will be mobilized with crutches and discharged once you can manage a flight of stairs. The average length of hospital stay is 4 to 5 days but can extend to 2 weeks depending on age, preoperative comorbidities and amount of deformity correction.
Also because the knee is a very superficial joint, you will be aware of swelling and bruising which will be far more obvious than compared to a hip replacement. The swelling can persist for as long as 3 months. The bruising can sink with gravity all the way down to the foot. The tissues and skin around the knee replacement will feel warm to touch for between 3 to 6 months. The knee will have a tendency to become very stiff and the emphasis for the rehabilitation is in fact forceful stretching and range of motion exercising.
After discharge you will have waterproof dressings for showering and these will come off at the two week follow up visit with myself. I expect you to still to be on crutches at this point but some people are able to mobilize with a single crutch used like a walking stick on the non- operative side. Driving a motor vehicle before this time is possible and is in fact a good form of exercise. The exercise bicycle or the rowing machine in a gym would be a good type of exercise to perform in the early stages. After two weeks I will discuss a referral to outpatient physiotherapy for balancing exercises that enhance confidence in the leg and improve the sense of joint position or proprioception. During this period both active and passive stretching exercises are essential in order to, most importantly get your leg straight and secondarily to regain as much flexion as possible. One can expect an end point with regard to range of motion at 6 months.
On the rarer occasion some people become very stiff and if I am not happy with range of motion at the 6 week follow up visit then I will consider a manipulation under anaesthesia in order to forcefully tear any of the scar adhesions which may have formed inside the knee. In order to avoid this, the onus is on you to move the knee despite the pain.
Post operatively you will be on a course of anti-inflammatories, pain killers, ice packs as well as a two week period of blood thinning tablets to prevent deep vein thrombosis (clots).
Please remember that you will have a lot of muscle atrophy (wasting) before surgery and after surgery therefore, your muscles will tend to be very tired with activity and you may yourself feel quite weak. This will take anywhere from 3 to 18 months to settle down. I very strongly recommend that you continue with a program of stretching and regular walking in order to alleviate this problem. Learning to balance safely on the operated leg is also essential in improving your confidence with respect to the use of the leg.
Your exercise program will include the following exercises:
The quadriceps are the muscles on the front of the thigh and are important in stabilizing and extending your knee. Lie on your back with legs straight, together, and flat on the bed, arms by your side. Perform this exercise one leg at a time. Tighten the muscles on the top of one of your thighs. At the same time, push the back of your knee downward into the bed. The result should be straightening of your leg. Hold for 5 seconds, relax 5 seconds; repeat 10 times for each leg. Do 3 sets of 10 3 times per day.
You may start doing this exercise with both legs the day after surgery before you begin physical therapy. The amount of pain will determine how many you can do, but you should strive to do several every hour. The more you can do, the faster your progress will be.
Terminal Knee Extension
This exercise helps strengthen the quadriceps muscle. It is done by straightening your knee joint.
Lie on your back with a blanket roll under your involved knee so that the knee bends about 30-40 degrees. Tighten your quadriceps and straighten your knee by lifting your heel off the bed. Hold 5 seconds, then slowly your heel to the bed. You may repeat 10 times and do 3 sets of 10 3 times per day.
Each day you will bend your knee. The physical therapist will help you find the best method to increase the bending (flexion) of your knee. This is usuall done over the side of the bed or a high chair or desk. Every day you should be able to flex it a little further.
Straight Leg Raising
This exercise helps strengthen the quadriceps muscle also.
Bend the uninvolved leg by raising the knee and keeping the foot flat on the bed. Keeping your involved leg straight, raise the straight leg and bend at the hip to 45 degrees. Hold for 5 seconds. Lower the leg slowly to the bed and repeat 10times. Do 3 sets of 10 3 times per day. This exercise promotes good control of the leg for getting in and out of bed and walking with crutches.
Use of heat and ice
Ice: Ice may be used during your hospital stay and at home to help reduce the pain and swelling in your knee. Pain and swelling will slow your progress with your exercises. A reusable ice pack will be given to you immediately after surgery. Place this on the knee for 30mins every 4hrs, but never directly on skin. Your sensation may be decreased after surgery, so use extra care.
Heat: Later on when stiffness is more of problem then this same “ice-pack” can be used as a “heat-pack” (see instructions on inside), and you may use heat before exercising to assist with gaining range of motion. Your sensation may be decreased after surgery so use extra care and always only use for 15 to 20 mins and do not place directly on your skin.
What happens after I go home?
- You will continue to take medications as prescribed.
- You will be sent home on prescribed medications to control pain. Plan to take your pain medication 30 minutes before exercises. Preventing pain is easier than chasing pain. If pain control continues to be a problem, call your doctor.
- Continue to walk with crutches/walker.
- Bear weight and walk on the leg as much as is comfortable.
- Walking is one of the better kinds of physical therapy and for muscle strengthening.
- However, walking does not replace the exercise program which you are taught in the hospital. The success of the operation depends to a great extent on how well you do the exercises and strengthen weakened muscles and on how much you stretch.
- If excess muscle aching occurs, you should cut back on your exercises rest for a day and begin again the next day.
Keep the incision clean and dry. See wound care under general topics. Also, upon returning home, be alert for certain warning signs. If any swelling, increased pain, drainage from the incision site, redness around the incision, or fever is noticed, report this immediately.
Prevention of Infection
If at any time (even years after the surgery) an infection develops from a skin wound, sore throat or pneumonia, notify your physician. Antibiotics should be administered promptly to prevent the occasional complication of distant infection localizing in the knee area. This also applies if any teeth are pulled or dental work is performed. Inform the general physician or dentist that you have had a joint replacement. You should obtain a medical alert card/bracelet.