Total Knee Rehabilitationby David Rhoads M.D. on 08/17/13
As a physical therapist, I am regularly asked by patients, “How long will rehab take?”. This is a complicated question to answer because, as I learned in physical therapy school, “It depends.”
So what does it depend on, you ask? Some factors will depend on your previous level of functioning such as, how good your range of motion was prior to surgery. Did you end up with an infection or any other complications following your surgery. Also, your weight will be a large factor in healing. If you are morbidly obese, then the extra weight on the prosthetic can cause difficulty with your overall ability to exercise. If you have any co-morbidities, also called pre-existing conditions, such as Diabetes, blood flow problems, or breathing difficulties. All these can slow the body’s ability to send healing factors to your knee in order for the body to heal itself quickly. Smoking is another factor which will inhibit the process of healing.
After your brief stay in the hospital you will have a few options to choose from depending on your level of independency and home assistance. If you live alone, you may need to go to a live-in rehabilitation facility to received therapy until you are able to demonstrate independent walking on a walker or cane, be able to go up and down stairs (if you have them in your home), and in and out of bed or car. If you have family or assistance at home, then you may be eligible for home health physical therapy. A therapist will come to your house for treatment. This can range from 2-6 weeks. Home health is limited to what you can do around the house, so getting to an outpatient facility as quickly as possible can decrease your overall time spent in therapy. Outpatient therapy has equipment that can help you accelerate your rehab, such as strength machines, pain modalities and other exercise equipment.
“When can I drive?” Doctors tend to allow 6 weeks post-op before allowing you to drive but this can depend on a few things. If you are still taking pain medication, strength in your leg, use of a walker, range of motion and if it was your right or left knee joint replaced.
Factors that you can control are your compliance with a home exercise program and the plan of care set for you during your first visit in an outpatient setting. Your home exercise program is usually prescribed for 2-3 times a day and to attend outpatient therapy 2-3 times a week. You are an active participant in your recovery and need to follow directions prescribed by your therapist for a speedy recovery.
Functional knee flexion (bending) can range from 110 degrees to 130 degrees. I like to have my patients reach 120-125 degrees to make sure they are functional without tightness during activities such as walking up and down stairs, in and out of a car or kneeling. Functional knee extension (straight) needs to be at 0 degrees. This means that your knee needs to be completely straight in order to walk correctly so that you don’t end up with problems in the back or hip down the road. Extension is very important to achieve as soon as possible. The longer it takes to reach 0 degrees, the harder it becomes.
Yes, I did say kneeling in the previous paragraph. You can kneel again! Will it be comfortable in all patients, No. But it can be done and with great success if done correctly. Think about it, if you fall down, how are you supposed to get up? What if you’re an avid gardener or like to get on the floor with your grand-children. I would start out on a pillow or cushion. Kneeling involves your hips more than your knee, so if you have strong hip muscles, then you should be able to kneel and stand up. The outpatient therapist can assist in teaching you how to get up and down from a kneeling position.
All this said, a typical total knee replacement will take about 2 months to achieve a functional state of range of motion and strength. This does not mean that you can stop doing your exercises once you’re released. It may take up to one year to completely heal and maintain your range. Just like people who exercise on a regular basis, 3-4 times a week to stay healthy, you need to continue your exercises at least once a day and transition into a regular workout routine.