Knee Replacement Frequently Asked Questions
Listed below are frequently asked questions about knee replacement surgery.
What is arthritis and why does my knee hurt?
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 this smooth cartilage. Eventually it wears down to bone. Rubbing of bone against bone causes discomfort, swelling and stiffness. Arthritis is detected with x-rays. Sometimes the doctor will order a special MRI prior to your surgery.
What is a knee replacement?
A knee replacement is really a cartilage replacement with an artificial surface. The knee itself is not replaced, as 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 occasionally the patella (kneecap). This creates a new smooth cushion and a functioning joint that does not hurt.
What are the results of total knee replacement?
Ninety to ninety-five (90-95%) percent of patients achieve good to excellent results with relief of discomfort and significantly increased activity and mobility.
When should I have this type of surgery?
Your orthopedic surgeon 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.
Am I too old for this surgery?
Age is not a problem, 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 opinion about your general health and readiness for surgery.
How long will my new knee last and can a second replacement be done?
We expect most knee replacements to last more than 15-20 years. However, there is no guarantee and 15-20 percent may not last that long. A second replacement may be done if necessary.
Why do they fail?
The most common reason for failure is loosening of the artificial surface from the bone. Wearing of the plastic spacer may also result in the need for a new spacer.
What are the major risks?
Most surgeries go well, without any complications. Infection and blood clots are two serious complications that concern us the most. To avoid these complications, we use antibiotics and blood thinners. We also take special precautions in the operating room to reduce risk of infection and blood clots such as using space suits and special stockings to pump blood through your legs. Complications can also occur to your skin, arteries, veins, nerves, tendons, ligaments, and bones. Overall, the complications rates are historically between 10-15%. You will view a video describing these and an informed consent will be reviewed with you. Your surgeon has already discussed these with you during your visit, but if you have any further questions or concerns, please ask us at anytime.
Should I exercise before the surgery?
Yes. You should either consult an outpatient physical therapist or follow the exercises listed in the back of this book under Patient Exercise Guide. Exercises should begin as soon as possible.
Will I need blood?
Most patients do not require blood transfusions after knee replacement surgery. We use many techniques to reduce blood loss and the need for transfusion. You will have several tests, including blood work, done prior to surgery. The doctor will use these results to anticipate your need for blood products. All patients will be asked to take Vitamin C and Iron starting six weeks prior to surgery. The Vitamin C helps your body absorb the Iron, which assists in maintaining your hemoglobin before and after the surgery. You can purchase a low-cost package of both of these in our office. If you do need blood following surgery, we recommend the blood from the blood bank. This blood is screened thoroughly for infectious disease. The American Red Cross recommends the blood bank, as they consider it safer and more effective than self-donation.
How long am I incapacitated?
You will probably stay in bed the day of your surgery. However, the next morning you will get up, sit in a chair or recliner and should be walking with a walker or crutches later that day. Most patients receiving a uni-compartmental (1/2 knee) will be able to walk in the hallways the first day.
How long will I be in the hospital?
Most knee patients will be hospitalized for three days after a total knee arthroplasty. Patients receiving a uni-compartmental (1/2 knee) will leave the next day. There are several goals that you must achieve before you can be discharged. Ultimately, we want you to have a safe recovery. How long this takes varies with each patient.
What if I live alone?
Two options are usually available to you. You may either stay at a sub-acute or extended care facility (ECF) following your hospital stay, or you may consider private nursing services. The benefits of an ECF include the ability to have daily physical therapy and additional exercise facilities. However, many of our patients who live alone have also arranged for continual home care through their family, local church, or social group, during the first three weeks after surgery. If you decide on private nursing services, we can provide a list of unendorsed service centers for you to review. Uni-compartmental knee patients (1/2 knee) usually go directly to their home after discharge from the hospital.
Will I need a second opinion prior to the surgery?
A second opinion is always a good idea when considering any type of surgery. This can be arranged through our office or through your family physician. We will be more than happy to provide you with some recommendations.
How do I make arrangements for surgery?
After your surgeon has scheduled your surgery, the surgical scheduler in our office will contact you. She will send you information in the mail detailing all of your upcoming appointments.
How long will the surgery take?
We reserve approximately two to two-and-a half hours for surgery. Some of this time is taken by the operating room staff to prepare for the surgery. However, it is not uncommon for some surgeries to take over 3 hours.
Do I need to be put to sleep for this surgery?
You may have a general anesthetic, which most people call "being put to sleep." However, an overwhelming majority of patients prefer to have a spinal anesthetic. Spinal anesthetic numbs your legs, providing you with prolonged pain relief, protecting you from blood clots and allowing for "twilight" sedation. The choice is between you and the anesthesiologist. For more information about anesthesia, read "Anesthesia and You", in your notebook appendix.
Will the surgery be painful?
You may have discomfort following the surgery, but we will keep you comfortable with appropriate medication and relaxation techniques. Generally most patients are able to stop very strong medication within one day. We continually improve and refine our pain control methods to assure a good recovery and fit the best method of pain relief to your specific needs.
Who will be performing the surgery?
Your orthopedic surgeon will do the surgery. An assistant often helps during the surgery and that assistant will bill your insurance separately.
How long, and where, will my scar be?
The scar will be approximately six inches long. It will be straight down the center of your knee, unless you have previous scars, in which case we may use the prior scar. Afterwards, there may be some numbness around the scar. This will not cause any functional problems. We use skill and care to make the scar as cosmetically appealing as possible.
Will I need a private nurse?
No. You do not need a private nurse, but if you want one, the Discharge Planning Nurse can help provide a list of references. If you do not have someone taking care of you at your home, you may also need to arrange for private nursing. Your insurance is unlikely to reimburse for this benefit.
Will I need a walker or crutches or cane?
Yes. For about six weeks, we do recommend that you use a walker, a cane or crutches. Arrangements for a walker or crutches will be made at orientation or during your hospital stay. However, you may bring your own or a borrowed one if you have one available to you.
Will I need any other equipment?
Yes, a raised toilet seat will be provided. A tub bench and grab bars in the tub or shower may also be necessary. An occupational therapist can help you decide. Some patients will use braces. This will be decided at the time of discharge and we will make all necessary arrangements for delivery.
Where will I go after discharge from the hospital?
Most patients are able to go home directly after discharge. Some may transfer to an extended care facility. Stays there are usually from one to three weeks long. Scheduling your stay at an extended care facility does not take place until after your surgery is performed. The Discharge Planner will help you with this decision and make the necessary arrangements. However, the final decision is technically up to you and your family. Check with your insurance company to see if you have extended care or rehab benefits. Extended care facility stays are typically not a benefit for uni-compartmental knee replacement patients.
Will I need help at home?
Yes. The first several weeks, depending on your progress, you will need someone to assist you with meal preparation, etc. We normally require that someone stay with you around the clock for the first 3 weeks after surgery. Everyone recovers at different rates but we normally recommend 3 weeks of care. Family members or friends need to be available to help.
Preparing ahead of time can minimize the amount of help needed. Having the laundry done, house cleaned, yard work completed, clean linens put on bed and single portions of frozen meals will reduce the need for extra help.
Will I need physical therapy when I go home?
Yes. We will arrange for physical therapy to be provided in your home for the first three weeks after surgery. Then you will continue with a physical therapist outside the home for another three weeks. Uni-compartmental knee recipients generally go directly to six weeks of outpatient therapy. Most patients choose to have their outpatient therapy at our office. The length of time required for therapy varies with each patient and your doctor will make adjustments as necessary.
How long until I can drive and get back to normal?
The ability to drive depends on whether surgery was on your right knee or your left knee, and the type of car you have. If the surgery was on your left knee and you have an automatic transmission, you could be driving at three weeks. If your surgery was on your right knee, your driving could be restricted for six weeks.
When will I be able to get back to work?
We recommend that most people take at least one month off from work, unless their job is quite sedentary and they can go to work with crutches. However, some people require 6 to 12 weeks to return to more demanding work. Patients having a uni-compartmental (1/2 knee) replacement may be able to return to work in 3-4 weeks.
When can I have sexual intercourse?
The time to resume sexual intercourse should be discussed with your orthopedic physician. Information is available on safe sex after a joint replacement from the Joint Care Coordinator.
How often will I need to be seen by my doctor following the surgery?
Two to three weeks after discharge, you will be seen for your first post-operative office visit. The frequency of follow-up visits will depend on your progress. Most patients are seen at six weeks, twelve weeks, six months and then yearly.
Do you recommend any restrictions following this surgery?
Yes. High-impact activities, such as running, singles tennis and basketball are not recommended. Injury-prone sports, such as downhill skiing, are also dangerous for the new joint.
What physical/recreational activities may I participate in after my recovery?
You are encouraged to participate in low impact activities such as walking, dancing, golfing, hiking, swimming, bowling and gardening. Most patients can return to stationary bike riding or elliptical machines in 3-4 weeks. Treadmills may be used on a low speed and with no incline at 4 weeks or later. Weight machines are used with your therapist after the 4th week and continue until you are discharged. Your physical therapist can answer specific questions about special exercises and machines.
Will I notice anything different about my knee?
Yes. You may have a small area of numbness to the outside of the scar that may last a year or more and is not serious. Sometimes, however, this numbness is permanent. Kneeling may be uncomfortable, but will not injure the knee replacement. Some patients notice some clicking when they move their knee. This is the result of the artificial surfaces coming together and is not any cause for concern. In addition, most patients have some swelling and warmth to the knee and leg that may last up to one year. This swelling is usually not associated with any pain.
A few days after I went home from the hospital, I noticed more bruising and swelling. Why?
Swelling and bruising, which occurs about 3-6 days after discharge from the hospital, is normal. This is due to the echymosis (or bruising) produced during the surgery itself. It works its way up to the surface of the skin, where it is visible. This is normal and will subside in about 2 weeks. During this time after surgery, it is very important to elevate and apply mild heat to these areas to reduce the symptoms. We recommend using a heating pad on the low setting, 20 to 30 minutes at a time, 2-4 times daily. You should continue to use ice over the incision itself. If you notice any increasing calf pain, please call our office as soon as possible. Occasionally patients will notice some blisters on their surgical leg at their period of maximum swelling. This is because there is no room available for the swelling and fluid to go within the skin and therefore pockets or blisters form. These should not be popped. If they pop on their own, cleanse them with warm soapy water and leave them open to air. If you have any concerns of infection, contact us immediately.
Can I place a pillow under my knee to keep it bent and make it more comfortable?
No! Definitely not. We understand that after surgery it may seem like a good idea to put a pillow under your knee. However this is something you should not do. Placing a pillow under your knee would allow your knee to stay slightly flexed. This can cause contractures or problems with how far you are able to extend your knee in the future. To prevent this, we ask that you DO NOT place a pillow under your knee. To elevate the leg, you may use a pillow or stool under your ankle.
When can I stop taking Iron and Vitamin C?
The Iron and Vitamin C are important to help build up your blood count and aid in tissue healing after surgery. It is important to begin the Iron and Vitamin C six weeks prior to surgery. Iron can be constipating to some patients. Therefore, monitor you bowel movements, drink plenty of fluids and eat foods high in fiber. If you have any difficulties, consult your pharmacist regarding over-the-counter treatments for constipation. Following surgery, we do not require that you continue the Iron and Vitamin C.
What are the "six week blues?"
Approximately 5-6 weeks after surgery many patients begin to feel both depressed and frustrated. It is normal to have these feelings during this period. During the first 6 weeks you make great strides in the reduction of pain and with your range of motion. However, at the 6 week mark, you often feel as though you have "hit a wall" in your progress. At this point, it is important to realize how far you have come. Don't be discouraged. The key to getting off of this plateau is building strength. Muscle strength takes at least 8 weeks to build. Thus, until you reach 8 weeks after surgery, you are on a plateau. You will get through this! It is important to remember that your exercises will pay off. Continue to build strength by focusing on the strengthening exercises located in the back of this book and from therapy, for at least another 4-6 weeks. As time passes, you will slowly notice that you will feel better. The next phase you will enter is the endurance phase. During this phase, you will feel more tired than usual at the end of the day or even after a few hours of work. This phase lasts anywhere from 3-6 months and even up to a year in some patients. Generally, you will see this get better.
What about some drainage from my incision?
A layer of stitches are placed just below the skin. This is in place of metal staples or outer sutures on your skin. Although this special plastic surgery suture makes your incision look better, it will dissolve and sometimes this causes fluid collections under and above the skin. During the dissolving process, there will be some redness and swelling. In some cases, it may form a small amount of milky-white fluid, which looks like pus. It is only the bi-product of the dissolving suture. If this occurs, wash out the area with antibacterial soap and water and cover with a large band-aide for 24 to 48 hrs. Do not apply any gels or lotions to the area. After 48 hrs, this area normally dries up by itself. However, if this worsens, contact our office.