Knee Replacement Frequently Asked Questions

In the knee joint there is a layer of smooth cartilage on the lower end of the femur (thighbone), the upper end of the tibia (shinbone) and the undersurface of the patella (kneecap). This cartilage serves as a cushion and allows for smooth motion of the knee. Arthritis is a wearing away of the smooth cartilage. Eventually, the cartilage wears down to bone. Rubbing of bone against bone causes discomfort, swelling and stiffness.

A total knee replacement is really a cartilage replacement with an artificial surface. The knee itself is not replaced, as is commonly thought, but rather an artificial substitute for the cartilage is inserted on the end of the bones. This is done with a metal alloy on the femur and plastic spacer on the tibia and kneecap (patella). This creates a new, smooth cushion and a functioning joint that does not hurt.

Results will vary depending on the quality of the surrounding tissue, the severity of the arthritis at the time of surgery and the patient’s activity level.

Dr. Kang will decide if you are a candidate for the surgery. This will be based on your history, exam, x-rays and response to conservative treatment. The decision will then be yours.

Age is not a factor if you are in reasonable health and have the desire to continue living a productive, active life. You may be asked to see your personal physician for his/ her option about your general health and readiness for surgery.

All implants have a limited life expectancy depending on an individual’s age, weight, activity level and medical condition(s). A total joint implant’s longevity will vary in every patient. It is important to remember that an implant is a medical device subject to wear that may lead to mechanical failure. While it is important to follow all of Dr. Kang’s recommendations after surgery, there is no guarantee that your particular implant will last for any specific length of time.

Just as your original joint wears out, a joint replacement will wear over time as well. The most common reason for revision is loosening of the artificial surface from the bone. Wearing of the plastic spacer may also result in the need for a new spacer. Dr. Kang will explain the possible complications associated with total knee replacement.

Most surgeries go well, without any complications. Infection and blood clots are two serious complications. To avoid these complications, we use antibiotics and blood thinners. We also take special precautions in the operating room to reduce the risk of infections.

You may need blood after the surgery. Bank blood is considered safe.

Most knee patients will be hospitalized for three days after their surgery. There are several goals that you must achieve before you can be discharged.

Two options are usually available to you. You may return home and receive help from a relative or friend. In certain circumstances, you can have home health care or home physical therapy. You may also stay at a sub-acute facility following your hospital stay, depending on your insurance.

After Dr. Kang has scheduled your surgery, the pre-surgery nurses will contact you. The Total Joint Care Coordinator will guide you through the program.

We reserve approximately 2 hours for surgery. Some of this time is taken by the operating room staff to prepare for the surgery.

There are two types of anesthesia for knee surgery. A general anesthetic (being put to sleep), or a spinal anesthetic (which numbs your legs). The most common anesthetic is a spinal anesthetic with IV sedation. Dr. Kang and the Anesthesiologist will be able to discuss in further detail the differences between your anesthesia choices.

You will have discomfort following the surgery, but we will try to keep you comfortable with the appropriate medication. Generally, most patients are able to stop very strong medication within one day.

Dr. Kang will perform the surgery. An assistant often helps during the surgery.

The scar will vary in length depending upon your body makeup and size. It will be straight down the center of your knee, unless you have previous scars, in which case we may use the existing scar. There may be some lasting numbness around the scar.

No, you do not need a private nurse, but if you want one, please call our discharge planner prior to surgery.

Yes, a walker is recommended for 2-4 weeks, after that you will progress to a cane. A wheeled walker is preferred. Since you will not need a walker for too long, you may want to consider borrowing one from a friend or family member. Another option is borrowing one from a local service organization, club or church.

Most patients are able to go home directly after discharge. Some patients may transfer to a sub-acute facility, where they will stray from 2-3 weeks. The discharge planner will help you with this decision and make the necessary arrangements. You should check with your insurance company to see if you have sub-acute rehab benefits.

Yes, for the first several days or weeks, depending on your progress, you will need someone to assist you with meal preparation, etc. If you go directly home from the hospital, the discharge planner will arrange for a home health nurse to come to your house if appropriate. Family or friends need to be available for help if possible.

Yes, you will have either outpatient or in-home physical therapy. Patients are encouraged to utilize outpatient physical therapy. It is recommended you set this up before your surgery date. A prescription for your physical therapy will be given to you. The length of time required for this type of therapy varies with each patient.

You may have difficulty walking and returning to the lifestyle that you were hoping for. You may experience pain, continued swelling, a stiff knee and inability to straighten it.

The ability to drive depends on whether surgery was on your right leg or your left leg and the type of car you have. If the surgery was on your left leg and you have an automatic transmission, you could be driving at 2 weeks. If the surgery was on your right leg, your driving could be restricted as long as 6 weeks. Consult Dr. Kang or the therapist for their advice on your activity.

We recommend that most people take at least 1 month off from work, unless their jobs are quite sedentary and they can return to work with crutches. An occupational therapist can make recommendations for joint protection and energy conservation on the job.

10 to 14 days after discharge, you will be seen for your first postoperative office visit. The frequency of follow-up visits will depend on your progress. Many patients are seen at 6-weeks, 12-weeks, and then yearly.

Yes, high-impact activities such as running, tennis and basketball are not recommended. Sports such as downhill skiing are also dangerous for the new joint.

You are encouraged to participate in low-impact activities such as walking, dancing, golfing, hiking, swimming, bowling, and gardening.

Yes, you may have a small area of numbness to the outside of the scar, which may last a year or more. Kneeling may be uncomfortable for a year or more. Some patients notice some clicking when they move their knee. This is the result of the artificial surfaces.

There may be bruising around your incision, into your calf, and even into your thigh, which is normal after knee replacement surgery. We will use a tourniquet during your knee replacement, which is a tight band around the thigh itself, which can also cause bruising and some aching in the thigh itself. This is also normal.

Warmth after a total joint replacement, especially knees, is very common for the first 6 months. If there are no signs of infection, such as redness, swelling, pain, or fevers, then the warmth is normal. However, if you have concerns please call Dr. Kang’s office.