Medical Illustration © Nucleus Medical Media, Inc., www.nucleusinc.com
The Knee Joint
The knee is the largest joint in the body. Normal knee function is required to perform most everyday activities. The knee is made up of the lower end of the thighbone (femur), which rotates on the upper end of the shin bone (tibia), and the kneecap (patella), which slides in a groove on the end of the femur. Large ligaments attach to the femur and tibia to provide stability. The long thigh muscles give the knee strength.
Normal Knee Anatomy
The joint surfaces where these three bones touch are covered with articular cartilage, a smooth substance that cushions the bones and enables them to move easily.
All remaining surfaces of the knee are covered by a thin, smooth tissue liner called the synovial membrane. This membrane releases a special fluid that lubricates the knee, reducing friction to nearly zero in a healthy knee.
Normally, all of these components work in harmony. But disease or injury can disrupt this harmony, resulting in pain, muscle weakness, and reduced function.
Medical Illustration © Nucleus Medical Media, Inc., www.nucleusinc.com
Knee with Arthritis
The most common cause of chronic knee pain and disability is arthritis. Osteoarthritis, rheumatoid arthritis, and traumatic arthritis are the most common forms.
- Osteoarthritis usually occurs in people 50 years of age and older and often in individuals with a family history of arthritis. The cartilage that cushions the bones of the knee softens and wears away. The bones then rub against one another, causing knee pain and stiffness.
- Rheumatoid arthritis is a disease in which the synovial membrane becomes thickened and inflamed, producing too much synovial fluid that overfills the joint space. This chronic inflammation can damage the cartilage and eventually cause cartilage loss, pain, and stiffness.
- Traumatic arthritis can follow a serious knee injury. A knee fracture or severe tears of the knee ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function.
Conservative treatments such as non-steroidal anti-inflammatory medications, physical therapy and weight loss are recommended as first line treatments. Physical therapy can treat stiff and weak joints by improving knee motion and strength. Oral medications such as anti-inflammatories improve pain by decreasing the inflammation in the joint associated with arthritis. More invasive treatments include intra-articular or joint injections. Some patients may benefit from a steroid injection, which is a powerful anti-inflammatory medication that can relieve a patient of their arthritic symptoms for two to six months, on average. Patients with mild to moderate arthritis may be candidates for Supartz injections. This is a series of weekly injections into the knee joint. The thick substance, hyaluronic acid, is a chemical naturally found in the joint tissues and synovial fluid. It improves the quality of the fluid in the knee joint to increase its lubricating effect.
If a patient has failed the above treatment options or their arthritis is so advanced, a joint replacement is considered. During surgery, the diseased bone ends of the femur and tibia are cut away and replaced by a smooth metal covering. A plastic liner is placed between the metal components acting like a shock absorber. The arthritis on the back of the patella is also removed and replaced with a small piece of plastic. All of the metal and plastic components are fixed into place with special bone cement, allowing the patient to walk on the surgical knee immediately after surgery.
Realistic Expectations About Knee Replacement Surgery
An important factor in deciding whether to have total knee replacement surgery is understanding what the procedure can and cannot do.
More than 90% of individuals who undergo total knee replacement experience a dramatic reduction of knee pain and a significant improvement in the ability to perform common activities of daily living. But total knee replacement will not make you a super-athlete or allow you to do more than you could before you developed arthritis.
Following surgery, you will be advised to avoid some types of activity, including jogging and high-impact sports, for the rest of your life.
With normal use and activity, every knee replacement develops some wear in its plastic cushion. Excessive activity or weight may accelerate this normal wear and cause the knee replacement to loosen and become painful. With appropriate activity modification, knee replacements can last for many years.
Preparing for surgery
Once you have made the decision to proceed with surgery and have chosen a date for your knee replacement, it is time to start planning for the procedure and your recovery. It is best to prepare early. Arrangements should be made to meet with the following people before your surgical date:
- Your surgeon or PA will meet with you a few days before your scheduled surgery to finalize plans and answer any remaining questions you may have. The procedure, including risks and benefits, will be explained thoroughly to ensure complete understanding.
- Banner Joint Class: This is a mandatory class that is held every Friday at Del E. Webb Hospital. You will have a chance to meet the nursing and therapy staff, which will assist in your care during your hospitalization. This informational session will walk you through your hospital stay, expectations, goals, and discharge planning. You will feel more prepared for surgery and many of your questions will be answered.
- Primary Care Physician: We would like you to see your primary physician for medical optimization and clearance before your surgical procedure. Your primary doctor will review medical risk factors you have for surgery, discuss your medications, and make appropriate changes. Please call for an appointment with your primary physician after choosing a surgical date. You will need laboratory tests and other studies before surgery. If you have questions about what tests you need before surgery, our surgical schedulers can help you.
- In the hospital, your primary physician is invited to assist in your care after surgery. If your doctor is not available at the hospital, a covering hospitalist doctor may see you.
- Pre-anesthesia Interview: A surgical nurse who is specially-trained to prepare you for surgery will talk with you within a week of surgery and answer any questions about anesthesia. The nurse will review your medical information, test results and preoperative orders to ensure you are medically ready for your surgical procedure.
- Social Worker: For some patients, it may be helpful to meet with a social worker or case manager before surgery. This will be arranged on an individual basis. If you have a concern which is best addressed by a social worker, please inform your surgeon’s staff.
- Tests: Several tests may be needed to help plan your surgery: blood and urine samples may be obtained.
- Medications: Tell your orthopedic surgeon about the medications you are taking. He or she will tell you which medications you should stop taking and which you should continue to take before surgery.
- Dental Evaluation: Although the incidence of infection after knee replacement is very low, an infection can occur if bacteria enter your bloodstream. Treatment of significant dental diseases (including tooth extractions and periodontal work) should be considered before your total knee replacement surgery.
- Weight Loss: If you are overweight, your doctor may ask you to lose some weight before surgery to minimize the stress on your new knee and possibly decrease the risks of surgery.
- Urinary Evaluations: A preoperative urological evaluation should be considered for individuals with a history of recent or frequent urinary infections. For older men with prostate disease, required treatment should be considered prior to knee replacement surgery.
- Home Planning: Recovery is a gradual process and made easier by planning ahead. Consider the following items in preparing for your return home before your surgical procedure:
- Ask your spouse, children, friends or neighbors if they can assist you for a few weeks after your surgery.
- To simplify cooking, prepare a few meals in advance and freeze them.
- Place all kitchen utensils, bathroom supplies, wardrobe necessities in an easy to reach place so than you will not need to bend or reach to retrieve them.
- Remove throw rugs and clutter from traffic paths.
- Arrange your bedroom to allow extra space to get in and out of bed while using your walker, cane or crutches.
- Place a sturdy chair, not a recliner, with a firm seat cushion and arms near a table for reading material, television remote, telephone, and other supplies you may want. It is also helpful to have a footstool to elevate and straighten your knee.
- Ensure your safety during showering with a safety bar or hand rail in the shower and a bench or chair to sit on.
- If you have a low toilet, a toilet seat riser with arms will make getting on and off the toilet much easier.
There are some medications which are important to stop before surgery. If you are taking any of the medications below, please discontinue them as indicated, unless otherwise discussed with your surgeon. Some medications cannot be stopped due to medical conditions; your surgeon and primary physician will address this.
- Aspirin and aspirin containing products: 10 days before surgery
- Non-Steroidal Anti-Inflammatory (NSAIDs): seven days before surgery
This includes: Ibuprofen, Advil, Naprosyn, and Aleve
- This does NOT include: COX-II inhibitors such as Bextra or Celebrex
- Coumadin (Warfarin): usually five days before surgery. This needs to be discussed with your primary physician. For some patients, “bridge therapy” with low- molecular weight heparin injections (Lovenox) may be beneficial between the time you discontinue your Coumadin and the date of surgery. A blood sample may be drawn the morning of surgery to check your blood’s clotting ability.
- Steroids and Immunosuppressant’s (e.g. Prednisone, Arava, Enbrel, Methotrexate, etc.): Optimal to discontinue before surgery, but this will be discussed between you, your surgeon, and your primary physicians.
If you are a smoker, we recommend you stop smoking before surgery and continue to not smoke until your wound is healed or give up smoking all together. Smoking affects your body in many negative ways, including: decreasing your body’s ability to heal your wound, fight infection, and prevent medical complications.
Change in Medical Condition
If there is any change in your medical condition before surgery, such as: fever, cough, vomiting, diarrhea, skin breakdown, or other concerns, please notify your primary physician and your surgeon.
The Night before Surgery: Do’s and Don’ts
- Do take a shower the night before surgery; lightly scrub your affected knee and entire leg with the chlorhexidine scrub that can be purchased at your local pharmacy. Wash the rest of your body with anti-microbial soap and water. Do not apply any lotion or ointments to the skin on your affected leg.
- Do eat a light meal the night before surgery.
- Do pack a hospital bag with your necessities such as your personal care items, non-skid slippers, a comfortable robe, and an outfit to wear home. A jogging suit, sweat pants, or loose fitting slacks would be most suitable. It’s also a good idea to bring some reading material or activities to do during your hospital stay.
- Do bring all of your medications in their bottles to show your nurse.
- Do remove all nail polish.
- Do bring your walker to the hospital before discharge to trial with the therapist.
- Do NOT shave the area of surgery. If necessary, your surgeon will take care of it in the operating room.
- Do NOT eat or drink anything after midnight. When you arise in the morning, you may take your morning medications with a small sip of water.
- Do NOT bring any jewelry, cash, credit cards, or important items with you to the hospital. It is best these stay safe at home.
- Do NOT take your own medications in the hospital unless specifically told to do so.
What to Expect at Surgery
Morning of Surgery
Complete your usual morning routine the day of surgery including taking your instructed medications with a small sip of water. It is best to leave your skin clean and not apply makeup or any heavy lotions. Arrive at the hospital at your instructed time, ready for surgery.
At the Hospital
You will be checked in by the surgical staff and brought to the preoperative area to prepare for surgery. Here you will be asked to change into a hospital gown with support stockings. All your personal items will be marked and placed in a bag for you after surgery.
Once you are dressed, your nurse will take a complete set of vitals including blood pressure, heart rate, temperature, respiratory rate, and oxygen level. An intravenous line will be placed to administer fluids into your vein. Because you have been fasting, your body will require fluid supplementation through this intravenous line. It is also an access to administer medications during and after surgery.
A member of the anesthesia team will meet with you in the preoperative area. They will discuss with you the available types of anesthesia, recommendations, and answer any questions you may have.
Before being transported to the operating room, your surgeon will mark your operative site. It is also a good idea to empty your bladder before going to the operating room.
There will be a designated area for your family and friends to wait while you are having surgery. A surgical communicator will be available to keep your family and friends aware of your progress. Your surgeon will contact them shortly after the completion of surgery.
Once you have been prepared in the pre-operative area, you will be brought back to the operating suite. Here you will meet many faces, all whom play an important part in your surgery. The operating room personnel will help you onto the operating table and make you comfortable. Your surgeon’s staff will be present to ensure proper positioning and to prepare your knee for surgery. Once the anesthesiologist starts your anesthesia, you will fall asleep. If you have chosen to receive a spinal instead of general anesthesia, this will be performed. You will then receive sedating medications to keep you relaxed.
Post-Anesthesia Care Unit
After your surgery has been completed; you will be transported to the post-anesthesia care unit (PACU). Here, the nursing personnel will place you on monitors to follow your blood pressure, heart rate, oxygen level, alertness, along with your pain level. An important part of the PACU is to ensure that you are comfortable and stable after surgery. Pain medications will be administered as needed through your IV line. Often patients are nauseated after surgery and your nurse can give you medications for this. Oxygen will be administered through a facemask upon arrival and will be removed as you become more alert. Warm blankets are available to keep you warm and comfortable.
The average stay in the PACU is one to two hours, but can be longer. Your family and friends will be notified of your progress. Once the transfer criterion has been met and your nurse feels you are ready to leave the PACU, you will be brought to your hospital room. Your family will be notified and can then meet up with you in your hospital room.
Arrival on the Orthopedic Floor
After surgery and your PACU stay, you will be transferred to your hospital bed on the orthopedic floor. Here, highly-trained nurses and staff who specialize in orthopedic patients will care for you. Upon arrival to the floor:
- A nurse will meet you in your room
- A set of vital signs will be taken
- Your surgical dressing will be checked
- If a surgical drain is present after surgery, this will be monitored frequently.
- Your foot will be closely monitored for warmth, pulse, sensation and movement. If you experience any numbness or tingling in your foot, heel pain, or increased discomfort, you should alert your nurse.
- The IV will keep you hydrated.
- Your pain will be closely monitored and treated as necessary with oral pain medications and intravenous narcotics as needed.
- A compression stocking (TED) will be placed on your non-operative leg along with a squeezing device to promote circulation.
Care After Surgery
Many people will participate in your care after surgery. There is direct communication between all providers including your surgeon and their staff, the medical doctors, nurses, therapist, and the case manager. If you have any concerns or questions at any time, please discuss these with any of your healthcare providers who will then address it appropriately.
After surgery, it is normal to have pain or discomfort. Inform your nurse if you are uncomfortable and they can administer appropriate medications. You may be asked to rate your pain on a scale of 1-10, with 10 being the worst pain ever. If your pain is not being relieved with the ordered medications, your surgeon should be notified. The goal is to control your pain so that you can begin aggressive therapy immediately after surgery and start on the road to recovery.
If you are not nauseated after surgery, you will be able to start on oral pain medications immediately. Otherwise, you may receive intravenous medications. By postoperative day one, we would like to have your pain managed by oral pain medications. With new surgical techniques including smaller incisions, less invasive surgery, and local anesthesia, patients have less postoperative pain that can be treated with lower dose pain medications. This allows you to feel less groggy and be more active with therapy.
Antibiotics will be administered through your IV before and after surgery. Usually patients will receive antibiotics for the first 24-48 hours after surgery. Antibiotics are important to reduce your risk of infection after surgery.
Once you are alert and feeling well, you may begin taking oral liquids such as ice chips and water. If you tolerate this without nausea, you can order a light meal the night of surgery or the following day. It is important to advance your diet slowly. If you do become nauseated or vomit, you should stop eating and notify your nurse who can administer medications to relieve this. Restart with liquids once you are feeling better. You must tolerate a regular diet before you leave the hospital.
After surgery, it is important to exercise your lungs. You will be given an incentive spirometer upon arrival to the hospital floor and instructed on its use. Take a slow, deep breath in, hold it for a few seconds and then breathe out. You should feel your lungs expanding. The spirometer will help you monitor the volume of air you are taking in. Work on increasing this volume daily. It is important to exercise your lungs frequently throughout the day. You will be encouraged to use your incentive spirometer 10 times every hour that you are awake.
It is important to promote circulation after any surgery, especially after orthopedic surgery. This will help decrease your chance of forming a blood clot. Immediately after surgery you will have a surgical dressing on your operative leg and a support stocking (TED hose) on your non-operative leg. On postoperative day two, your surgical dressing will be removed and your new dressing held in place by a TED hose. You should wear your support stockings (TED hose) throughout your hospital stay and for the following six weeks. Another circulatory aid is a compression device, which will also be used after surgery. The sequential compression device (SCD) is a sleeve that wraps around your lower leg, routinely inflating to promote circulation. When you are resting in bed, the SCD should be used. If you experience discomfort, tingling or numbness, you should notify your nurse immediately.
A blood thinner will also be started after surgery to reduce your risk of blood clots. Starting the day after surgery, you will receive a superficial injection of a blood thinner in the skin on your abdomen. This will continue while you are in the hospital. You will be discharged from the hospital on either 325 mg of aspirin twice a day or Coumadin (Warfarin), depending on your other medical conditions and your risk of blood clots. These medications are continued for six weeks, or until you have returned to an active lifestyle.
An easy way to help prevent blood clots is to increase your circulation with activity. Work on your exercises a minimum of three times a day and walk regularly after surgery. It is important to remain as active as possible. This is also good for your overall health.
The evening of surgery, the nursing staff will help you get out of bed and up in a chair. They will discuss activities you can do on your own to encourage motion and promote circulation. The physical therapist will also see you the evening after surgery and help you ambulate. You will be fitted for an appropriate gait aid such as a walker or cane to assist you during recovery. If you have these items at home, please bring them to the hospital.
Throughout your hospital stay, you will be encouraged to work on your exercises in your room and ambulate through the halls. In the beginning, you will likely need assistance when transferring from the bed, completing your daily tasks, and ambulating. The nursing staff is available to help you. Your family and friends may also participate in your care and help you with your activities.
Surgical Risks and Possible Complications
The complication rate following total knee replacement is low. Serious complications, such as a knee joint infection, occur in fewer than 2% of patients. Major medical complications such as heart attack or stroke occur even less frequently. Chronic illnesses may increase the potential for complications. Although uncommon, when these complications occur, they can prolong or limit full recovery.
Blood clots in the leg veins are the most common complication of knee replacement surgery. Your orthopedic surgeon will outline a prevention program, which may include periodic elevation of your legs, lower leg exercises to increase circulation, support stockings, and medication to thin your blood.
Although implant designs and materials as well as surgical techniques have been optimized, wear of the bearing surfaces or loosening of the components may occur. Additionally, although an average of 115° of motion is generally anticipated after surgery, scarring of the knee can occasionally occur, and motion may be more limited, particularly in patients with limited motion before surgery. In some cases patients may notice a small change in limb length. Finally, although rare, injury to the nerves or blood vessels around the knee can occur during surgery. Discuss your concerns thoroughly with your orthopedic surgeon prior to surgery.
The success of your surgery will depend in large measure on how well you follow your orthopedic surgeon’s instructions regarding home care during the first few weeks after surgery.
- Wound Care
You will have stitches or staples running along your wound or a suture beneath your skin. The stitches or staples will be removed approximately 2 weeks after surgery. Avoid getting the wound wet until it has thoroughly sealed and dried. A bandage may be placed over the wound to prevent irritation from clothing or support stockings.
Some loss of appetite is common for several weeks after surgery. A balanced diet, often with an iron supplement, is important to promote proper tissue healing and restore muscle strength. Be sure to drink plenty of fluids.
Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal light activities of daily living within 3 to 6 weeks following surgery. Some discomfort with activity and at night is common for several weeks.
Your activity program should include:
- A graduated walking program, initially in your home and later outside
- A walking program to slowly increase your mobility and endurance
- Resuming other normal household activities
- Resuming sitting, standing, and walking up and down stairs
- Specific exercises several times a day to restore movement
- Specific exercises several times a day to strengthen your hip joint
- You may wish to have a physical therapist help you at home
Avoiding Problems After Surgery
Blood Clot Prevention
Follow your orthopedic surgeon’s instructions carefully to minimize the potential risk of blood clots, which can occur during the first several weeks of your recovery.
Warning signs of possible blood clots include:
- Pain in your calf and leg that is unrelated to your incision
- Tenderness or redness of your calf
- Swelling of your thigh, calf, ankle, or foot
Warning signs that a blood clot has traveled to your lung include:
- Shortness of breath
Notify your doctor immediately if you develop any of these signs.
The most common causes of infection following knee replacement surgery are from bacteria that enter the bloodstream during dental procedures, urinary tract infections, or skin infections. These bacteria can lodge around your prosthesis.
Following your surgery, you may need to take antibiotics prior to dental work, including dental cleanings, or any surgical procedure that could allow bacteria to enter your bloodstream. For many people with joint replacements and normal immune systems, the American Academy of Orthopedic Surgeons (AAOS) recommends antibiotic prophylaxis before dental work.
Warning signs of a possible knee replacement infection are:
- Persistent fever (higher than 100°F orally)
- Shaking chills
- Increasing redness, tenderness, or swelling of the hip wound
- Drainage from the hip wound
- Increasing hip pain with both activity and rest
Notify your doctor immediately if you develop any of these signs.
A fall during the first few weeks after surgery can damage your new knee and may result in a need for more surgery. Stairs are a particular hazard until your knee is strong and mobile. You should use a cane, crutches, a walker, or handrails or have someone help you until you improve your balance, flexibility, and strength.
Your orthopedic surgeon and physical therapist will help you decide which assistive aides will be required following surgery, and when those aides can safely be discontinued.
A member of the surgical team would like to see you back two to three weeks after surgery for a wound check and staple/suture removal. At approximately eight and 16 weeks postoperatively, you will return for radiographs followed by an examination. If needed, your surgeon may ask you to return for a recheck at a time other than stated above. Each patient is an individual and may require a different follow-up schedule. Your first follow-up visit is usually arranged before surgery. If you did not receive an appointment or are unsure of your follow-up, please call our office.
A fall during the first few weeks after surgery can damage your new knee and may result in a need for further surgery. Stairs are a particular hazard until your knee is strong and mobile. You should use a cane, crutches, a walker, or hand rails or have someone to help you until you have improved your balance, flexibility, and strength.
Your surgeon and physical therapist will help you decide what assistive aides will be required following surgery and when those aides can safely be discontinued.
How Your New Knee Is Different
You may feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending activities. Improvement of knee motion is a goal of total knee replacement, but restoration of full motion is uncommon. The motion of your knee replacement after surgery is predicted by the motion of your knee prior to surgery. Most patients can expect to be able to almost fully straighten the replaced knee and to bend the knee sufficiently to climb stairs and get in and out of a car. Kneeling is usually uncomfortable, but it is not harmful. Occasionally, you may feel some soft clicking of the metal and plastic with knee bending or walking. These differences often diminish with time and most patients find them to be tolerable when compared with the pain and limited function they experienced prior to surgery.
The CORE Institute is dedicated to your outcome. If any questions or concerns arise, please call The CORE Institute at 1.866.974.2673.