Common Questions

Here are frequently asked questions and answers about knee replacements. If you have further questions please ask your surgeon or a member of the Spine & Orthopedic Center team.

What is arthritis and why does my knee hurt?
Smooth cartilage is present in the healthy knee: on the lower end of the femur or thigh bone; and the upper end of the tibia or lower leg bone; and the undersurface of the patella or kneecap. This cartilage allows for a smooth-gliding surface and cushions the weight load on this joint. Arthritis is the wearing away of this cartilage leading to pain, discomfort and swelling.
What is knee replacement surgery?
Total knee replacement is a surgical procedure in which a knee joint that is worn out or injured and painful is replaced with an artificial joint. The surgery will benefit you by reducing knee pain, increasing leg strength and providing easier movement.
How is the knee replaced?
An incision is made on the front or side of your knee and the damaged bone is cleared away. The surfaces are prepared and shaped to hold the new joint. The new joint is aligned and secured to the thighbone, kneecap and shinbone.
What is Computer Assisted Surgery?
The use of computer navigation in surgery has revolutionized the total joint replacement procedure. With the utilization of computer navigation, artificial joint components are accurately placed, which allows incredible precision in overall limb alignment and a promise of increased longevity of the joint replacement. Joint replacement surgeries using computer navigation have significantly smaller incisions which also reduces the amount of operative trauma for patients.
Am I too old for this type of surgery?
As long as you are in reasonable health and desire to devote time and effort into the rehabilitation process, you are a candidate for this type of surgery.
What does a total knee replacement involve?
The tibia and the bottom of the femur are both shaved down surgically. A metal implant is then secured into the femur above the knee and a plastic spacer is inserted in the tibia below the knee. Your kneecap is resurfaced with a plastic kneecap. All these parts slide smoothly across each other.
What are the major risks associated with this surgery?
Infection and blood clots are two of the biggest risk factors involved with a joint replacement. To avoid complications, antibiotics are started just prior to your surgery and continue until drains are out of the incision. We also use early mobility, mechanical stockings and blood thinners to minimize risk of blood clots.
Should I exercise before this surgery?
Yes, we see faster and safer mobility in the patient who has taken measures to strengthen muscle groups. You will have soreness and stiffness after your surgery that will require more effort to get up and around. The better toned your muscle groups are, the easier the rehabilitation process will be for you. The physical therapist can suggest exercises to perform before surgery.
How long does the surgery take?
Total operating time from skin incision to closure is about one hour to an hour and a half. The time elapsed from entering the operating room to exiting into recovery is two to two and a half hours. This time includes anesthetic induction, positioning and surgical site preparation; it is not all operating time.
How painful is a knee replacement?
You will have discomfort after your surgery. The initial 8 to 10 hours out of recovery prove to be the most painful. The staff is specifically trained for post-operative pain management. Your RN will work closely with you to insure that you are as comfortable as possible. You will initially require IV narcotic pain medication. Most patients are able to stop using IV narcotics and take pain pills with breakfast the day after surgery. It is important to keep in mind that extended use of IV narcotics has proven to slow the body’s ability to stabilize blood pressure, pulse, and fluid volumes. Narcotic medications slow digestion, which increases risk of nausea and poor appetite. Narcotic medications also decrease your ability to participate and make decisions in your care. It is a misconception that IV narcotics are the best way to handle surgical discomfort. We often find that many patients experience fewer complications and mobilize much safer with the use of oral pain medication. There are non-medicinal approaches to pain relief that are also very effective in the total knee replacement patient.
What can I expect after my total knee replacement?
No two patients experience the same recovery or results after knee replacement surgery. The most important component of knee replacement surgery is rehabilitation after the procedure, consisting primarily of exercises to decrease stiffness and soreness.
Will I have a scar?
Yes, you will have a scar from the surgical incision. It will begin just above your knee joint and extend over and just below the bottom of the joint. Do not put anything on your incision other than what your surgeon specifically approved. Doing otherwise could lead to an increased risk of infection in your new joint.
How long will my new knee last?
A number of factors will affect the longevity of your new knee implant. Thus, there is no guarantee for a specific length of time for your implant to last. Factors that are under the control of the patient that can affect the longevity of a new knee joint include weight, physical activity and medical condition stability. It is important to remember that an implant is a medical device subject to wear that could lead to mechanical failure. Statistically, loosening or wear rates requiring repeat surgery are about 1 percent per year. In other words, about 90 plus percent of replacements will last 12 years and longer.
What causes loosening of a new implant?
The loosening of the artificial surface from the bone is the most common cause of need for revision of your knee joint. Also, wear and tear of your mechanical knee will occur over time. Your surgeon will explain these and other possible complications to you.
How long will I be in bed after surgery?
You will be assisted to stand up the evening of your surgery. We have found that the quicker patients get back up on their feet, the quicker the body’s hemo dynamics (appropriate balance in blood pressure, pulse, hemoglobin level and fluid volume) stabilize. Your first few times out of bed will require the assistance of one or two staff members. We will assist you up from bed for breakfast the morning after your surgery. Meals are served at tables – not in bed. Also, bedpans are not used, so you will be assisted up and out of bed to a bedside commode as needed. Please keep in mind that our staff is specifically trained to help patients with new joint implants get out of bed safely. Listen to the staff and use their tips.
How long will I be at the Spine & Orthopedic Center?
The average number of days in the hospital for joint replacement surgery is three; however, with the development of the total joint replacement program, shorter hospital stays are becoming more common.
Will I use a walker after surgery?
You will need a walker or some form of assistive device for stability when you walk after surgery. The period of time for using assistive devices has decreased with the implementation of total joint replacement programs. Your surgeon will evaluate how long you need to use a walker or crutches after your surgery at your follow-up appointments. Do not discontinue the use of your walker or crutches without checking with your surgeon.
Will I need help at home?
You will need some assistance and supervision with activities of daily living for a short amount of time. This amount of time varies with each patient. Some surgeries require a daily dressing change to your incision, which you will probably need help with. You should not need someone with you full time at home. Your occupational therapist will teach you how to handle daily activities prior to discharge. Preparing things before your surgery can reduce the amount of assistance you need after surgery. Having the laundry done, house cleaned, several meals prepared ahead of time, and clean linens on your bed will benefit you once you return home.
What if I live alone?
Most joint replacement patients can return home with only a few modifications to their home and a few hours of assistance daily from a family member or friend. As the days pass, you will become more confident with your ability to handle things again and your need for assistance will taper off. After the stitches or staples are removed from your incision, a dressing over it will no longer be needed.
Will I need physical therapy once I return home?
Total knee replacement requires consistent exercise and stretching to loosen tight ligaments and prohibit stiffness and swelling. Your surgeon or therapist will discuss the frequency and duration of your home health and outpatient physical therapy. It is very common to have a home health therapist three times a week for three weeks followed by outpatient physical therapy for another month after surgery. Unless your insurance company specifies where you need to go, there are several choices of therapy providers. You will need to have transportation arrangements made for outpatient therapy sessions.
What is a Continuous Passive Motion device?
Continuous Passive Motion (CPM) is a postoperative treatment method that is designed to aid recovery after joint replacement surgery. In most patients, joint motion following surgery causes measurable pain and as a result, patients fail to move the joint. This allows the tissue around the joint to become stiff and for scar tissue to form resulting in a limited range of motion. Passive range of motion means that the joint is moved without the patient’s muscles being used. Continuous Passive Motion devices have been developed for patients to use after surgery. By using a motorized device to very gradually move the joint, it is possible to significantly accelerate recovery time. Your case manager will assist you arrangements for a CPM device.
How long until I can drive again?
Your surgeon will instruct you on this prior to discharge.
When can I return to work?
Overall the recommendation is not to return to work for one month. There may be exceptions to this, largely dependent on what you do for a living. If you have specific questions about how to perform your job tasks once you can return to work, please ask our occupational therapist during your evaluation and treatment while in the hospital.
When will I see the surgeon again after hospital discharge?
You will have an office appointment scheduled before you are discharged. Your first appointment will be within 10 to 14 days to check your incision and you will see your surgeon at intervals determined by your progress.
What restrictions will I have after this surgery?
You will not be able to run, jump or perform such activities that could require high impact on your new joint. Injury prone sports are also restricted. No repeat lifting of 50 to 75 pounds or more.
What activities are encouraged / permitted after knee replacement?
Cycling, walking, dancing, golfing, swimming, bowling and gardening are all activities that can be performed moderately without the risk of high impact force on new joint replacement. If you wonder about further specific activities, please ask any member of the Spine & Orthopedic Center team.
Will this new knee feel different to me?
It is very common to have a small area of numbness outside of your scar line. This could last a year or more. You may also hear or feel a clicking noise when you move your new knee. This is merely artificial surfaces moving over each other and nothing to be alarmed about.