What can I expect during the hospital stay?
You can expect several professionals to see you and help you with recovery:
- A nursing assistant helps with bathing and activities you are unable to do yourself.
- A physical therapist helps with knee exercises and walking with an assistive device, such as a walker.
- An occupational therapist helps you with everyday activities – such as dressing and bathing – while your knee is recovering.
- An orthopaedic specialist sees you daily, as will a primary care doctor.
- Nursing staff attends to your daily needs, ensuring the doctor’s instructions are carried out and you are comfortable.
As you can imagine, the first night or two may be difficult. The hospital environment is new, the bed is not your own and you will have multiple medications in your system. If you have trouble sleeping in the hospital, please ask the nurse for a sleeping pill. Expect to take a nap during the day and anticipate several weeks before your normal sleeping patterns are restored, even after you go home.
How long will I be in the hospital?
Most patients are in the hospital for two to three days after a routine knee replacement; some need a longer duration of stay. A social worker communicates with your insurance about the expected length of stay and the duration approved by the insurance carrier. The social worker helps with discharge planning.
What measures are taken to reduce the risk of blood clots?
We routinely use a blood-thinning medicine called warfarin. This drug, or an alternative blood thinner, is taken for about two weeks after surgery to lower the risk of a blood clot. The hospital pharmacist monitors the blood-thinner dose and advises you if there is any change in the dosage.
After leaving the hospital, you will have a blood test twice a week, or more if necessary, to monitor the efficacy of the blood-thinner.
In addition, the exercises, foot pumps, lack of a tourniquet, efficient surgery and early walking after surgery all serve to minimize the risk of blood clots. We use a multi-modal program to reduce the risk of blood clots forming.
What else should I know about blood clots?
Any surgery increases the risk of blood clot formation. Some patients are genetically predisposed to clot formation and are at a higher risk. If you have ever had clots in the past, please be sure to let us know.
Clots can cause serious problems such as heart or vascular disease or a stroke. A lung injury can occur if the clot migrates to your lungs from the leg. A large enough clot migrating to the heart or lungs can be fatal.
Anticoagulation (blood-thinning) therapy is recommended after all knee replacement operations to reduce the likelihood of developing a clot. Even if a clot develops in the leg, if you are on a blood-thinner, the risk of the clot enlarging and migrating to the lungs is reduced. Exercises, spinal anesthetics, early mobilization, intermittent foot pumps and blood-thinning medications are all aimed at reducing the risk of blood-clot formation after surgery.
What should I know about the blood-thinning medicine I will be given?
The most common blood thinner used after knee replacement is the drug warfarin. It is an inexpensive medication that requires adjustment of the dosage for each patient.
You will take warfarin at the same time each day. The dose is based on a blood test that measures how quickly your blood clots. The results are recorded as PT (prothrombin time) and INR (international normalized ratio); the pharmacist looks at these test results and figures out how much warfarin you should take. The goal of taking warfarin is to keep your INR between 1.8 and 2.5. If you miss a dose of warfarin, take it as soon as you remember, but do not double the next dose.
Many things, such as diet, other medications, physical activity and illness can affect warfarin dosing. Vitamins, over-the-counter remedies, herbs, nutrition supplements and other alternative treatments also affect warfarin, and should not be taken while you are on warfarin.
Are there risks to taking a blood-thinner?
Yes, and the obvious risk is bleeding. By thinning blood, we increase the risk of bleeding (something that can be managed), and decrease the risk of clot formation (which can be lethal). Thus, there is a trade-off in risks. The risk of bleeding is common to all blood thinners.
Drugs sometimes used instead of warfarin include heparin and aspirin. Some people may not be able to take warfarin; in that case, we usually use a drug called enoxaparin. After about ten days of warfarin, or enoxaparin, we can switch patients to twice-daily aspirin; this combination is safe.
Side effects of warfarin and enoxaparin include dizziness, headache, weakness, cuts from shaving/injury that do not stop bleeding, nosebleeds, bleeding of the gums when brushing your teeth, vomiting blood, bruising or skin rashes, dark brown urine, red or black color to stools, unexpected vaginal bleeding, or unusual pain or swelling. If any such symptoms appear, we may have to switch to a different blood-thinner.
Warfarin interacts with many drugs, both prescription and over-the-counter. Special caution should be given to anti-inflammatory medications such as aspirin and ibuprofen-containing drugs; naproxen, ketoprofen, cimetidine and ranitidine; and food supplements that contain vitamin K.
Supplements, such as ginkgo biloba and danshen also interact with warfarin. Some herbal teas have tonka beans, melilot (sweet clover) or sweet woodruff in them, which contain vitamin K. In addition, foods containing fat substitutes such as olestra are supplemented with vitamin K.
Because so many dietary items affect warfarin, it is essential to monitor the action of this drug two or three times every week with blood draws that are done by the home health agency while you recover at home.
How do you prevent infections during knee replacement?
Scrubbing of the skin with an antiseptic, antibiotics given before surgery, surgeon experience, a team-approach designed to promote efficiency, and standardized protocols are some of the key steps in reducing the risk of infection. It is impossible to completely eliminate this risk, but we can get the risk down to nearly zero. It is very rare to have an infection after routine knee replacement.
Is there a long-term risk of infection in an artificial knee?
Yes, there is a lifetime risk of infection with any artificial implant in your body, whether a knee joint, heart valve or other synthetic component. As long as you maintain good health and appropriate body weight, avoid smoking, maintain proper hygiene, keep diabetes under control and promptly address even minor infections in your body, the risk of infecting an otherwise well-functioning knee implant is very low.
What if an infection does develop?
An early infection shows up as redness and pain around the healing incision. This can usually be treated with oral antibiotics alone, usually taken for five to ten days. Very rarely, as a precaution, the knee joint has to be opened up and washed out to clean the tissues and effectively treat an early infection. This usually happens if the knee starts draining fluid after surgery, which is a rare occurrence.
A late infection that happens months or years after surgery is more serious and requires additional surgery.
In these rare cases, the surgeon removes the infected prosthesis and implants a temporary antibiotic-loaded knee, to allow the patient to walk and function, while the infection resolves. After three or more months, a new knee joint is implanted. Six weeks of antibiotics and these two operations will effectively treat an established deep infection in the knee.
Fortunately, deep infections after knee replacement surgery are very rare, usually occurring in immune-compromised patients who have other serious medical problems.
What is the average length of hospital stay?
The length of hospital stay after knee replacement varies from just one day to five or more days. There is no standard formula. Each person and each recovery is different. Typically, a routine knee replacement requires two to three days in the hospital; there is little to be gained by trying to accelerate this process. People need time to heal.
How is the discharge from the hospital handled?
During your hospital stay, a case manager works with your doctor to plan your discharge, whether to your home, a skilled nursing facility, in-patient rehabilitation facility or nursing home. A social worker may also visit and work with the case manager to formulate a discharge plan.
What determines when I can go home after knee replacement?
You can go home when you are able to:
- Get into and out of bed
- Get to the bathroom
- Go up and down stairs (of standard, seven-inch height)
- Walk up to 75 feet with a cane, walker or other assistive device
Typically, you will have had a bowel movement before discharge and be able to take a shower. Your doctor is the one making the ultimate decision about the safety and timing of your discharge. You will need someone to drive you home from the hospital.
How much pain can I expect?
With modern surgery, pain can be controlled very well. Even though modern pain medicines are very effective, some aching and soreness in the knee may persist for many months. This is part of a normal recovery, as long as you notice steady improvement.
Each patient recovers differently; even two knees replaced in the same patient on the same date will recover differently. For example, effective pain control may be a problem for patients who take narcotics regularly before surgery. In these patients, pain relief can be hard to attain since the body desensitizes itself to narcotics.
Will there be persistent pain after surgery?
No, although pain perception varies greatly among patients and the time to full recovery is highly variable. The important thing to watch for is a steady decline in the level of discomfort; the knee should feel better month-to-month. If there is persistent pain – or increasing pain – then further inquiry is necessary. Remember, there will always be patients who go home in a day or two, and never seem to have any pain after knee replacement. Others recover far more slowly. The important thing to remember is that both types of recovery are entirely normal.
Should I apply ice or heat to the knee as it is healing?
After surgery, and for the first two weeks, ice is more effective in reducing swelling and pain. After complete healing of the skin and removal of staples, you can use a moist heat pack if it feels comfortable. Once healed, soaking the knee in a hot tub helps, too.
How long should I take pain medicines?
Most patients use the narcotics we send them home with for anywhere from one to three months. Over time, they taper off and begin anti-inflammatory medicines and other non-addictive medicines for pain by three months.
Narcotic drugs taken over a long time creates a tolerance that makes them decreasingly effective. That is why it is preferable to taper off narcotic drugs after three months, unless there are compelling reasons to continue use. This is a general observation; some patients require narcotic medications for a longer period of time.
What if I need narcotics three months after surgery, or if I have been taking them before surgery?
In such cases, the doctor who was filling the prescriptions before surgery may resume dispensing the medication. Very rarely, referral to a pain specialist is necessary for patients who are dependent on long-term narcotics. These medications are carefully monitored and tracked in the pharmacy databases, and specialized pain doctors are better trained and equipped to monitor their long-term use.
If you were taking narcotics regularly before surgery, pain control is usually more difficult and complicated since the body is desensitized to the pain control medicines we use after surgery. In such cases, let us know what you are taking before surgery so we can adjust pain medicines accordingly.
There are no hard rules. We are here to help and recognize every person is different and pain is very individual.
How will I manage at home?
After knee replacement surgery, you will need help at home from an adult family member or friend. If this is not possible, it may be necessary to stay at an inpatient rehabilitation facility. You will not be able to drive for the first couple of weeks.
A home health agency checks on you at home, about three times a week or more, to help with walking, exercise, incision checks, medications and communication with the doctor. The home health agency provides a:
- Nurse to do blood draws and follow-up care
- Occupational therapist to assist you with activities of daily living (optional)
- Physical therapist to continue therapy
The nurse also communicates with our office to regularly update us on your progress.
While at home, if a concern arises, please call or email our office. If there is a worry about the incision, taking a digital photo and sending it by email works very well.
When do I have to come back to see the doctor after knee surgery?
You will return for a visit about one month after your operation. If you have problems or questions before then, do not hesitate to call or e-mail. Your home health nurse is also an excellent resource. Patients coming from far away have communicated by e-mail, used digital photos of their incisions, and sent digital X-rays the same way; this works very well and saves a lot of driving and time.
Under what circumstances should I contact a doctor?
You should contact our office if you have any of the following:
- Any other concern – even if it seems minor
- Drainage from your incision
- Excessive redness around the incision
- Increase in the incision pain
- Increased leg swelling
- Numbness or tingling down the back of the operative leg
- Pain and swelling in the calf of the leg
- Temperature about 101 degrees Fahrenheit
Your family doctor may be your closest resource for advice if you develop a cold, flu, nausea, vomiting, diarrhea or constipation. If you are unsure which doctor to call, call your surgeon.
If you cannot reach a doctor and feel there is a problem, please go to the nearest emergency room. It is best to be vigilant and not take chances.
Why do I hear a popping noise in the new knee?
Clicking, popping and other noises in the knee alarm many patients. These are the harmless result of synthetic joint surfaces making contact with each other and are common to all prosthetic knee components. The sounds may change over time, may disappear entirely or may persist. The noises of an artificial knee joint take some getting used to.
Why are my appetite, mood, food-taste and sleep different after knee replacement?
Altered appetite, bowel habits, depression and mood swings are common after any major elective surgery, including knee replacement. This is very important to know, understand and anticipate. In some cases, medications might be necessary to control such symptoms.
All surgery elicits powerful psychosocial and physiological responses from the patient and varies from one person to another. These responses are normal, and we will help you get through them. It takes time for the body, mind and soul to recover from any invasive operation.
Why is the outside of my knee numb?
Numbness in the surrounding area is normal after all knee surgery. The incision cuts small nerve fibers that run from inside to outside of the knee, so the skin to the outside of the cut always feels numb after knee surgery. Usually, this sensation resolves over time and is not a major problem for patients. Most patients will not notice that the outside of the scar feels numb.
Is it normal for the muscles to spasm and tighten after surgery?
Yes. Sometimes unexpected spasms of the leg muscles occur after surgery, usually as the person is healing from the operation. These spasms will go away. If they are particularly troublesome, we can prescribe a muscle relaxant medicine, which can help.
Will my leg be longer after knee replacement?
Not noticeably, since it is not possible to lengthen or shorten a leg after knee replacement surgery. The reason is that blood vessels and nerves behind the knee present a practical limitation. Some patients say the leg feels slightly longer. This comes from straightening out a crooked leg, which ends up feeling longer as a result. The sensation disappears as the patient gets used to having a normally aligned leg again.
How long is the scar for knee replacement?
In most cases, a four- to five-inch incision is enough for knee replacement surgery. We use the shortest possible incision length in combination with the other less invasive techniques discussed elsewhere in this guide. Incision length ultimately depends on each patient’s disease severity, anatomy and amount of body fat.
Many orthopaedic implant companies have developed special instruments to assist in making shorter incisions, and provide training on their effective use. The general rule is to make the incision as short as possible, without compromising the accuracy, precision or safety that is required for a successful long-term outcome. Since each patient is different, incision length can vary from person to person, even though the same type of knee replacement implants may be used.
Who will remove the staples from the incision?
For the first month, a home health nurse visits you to:
- Check the incision
- Do blood work to monitor the blood thinner
- Help you exercise and walk
That person should remove stitches no earlier than 21 days (three weeks) after surgery.
If there is any question about healing, it is safer to wait another week before removing stitches. Home health nurses can take a digital photo of the incision if there is a concern and send it to us via email.
The preferred method to remove staples is to remove every other one, and apply adhesive-reinforced tape strips to ensure the skin stays together. If there is any concern about the skin edges coming apart, the rest of the staples can be left in for another week; delayed healing can occur in patients with a history of poor wound healing, cancer, diabetes, obesity and other factors.
Please share this information with the home health person if there are any questions about staple removal. It is safe to shower anytime after staples are removed. Immersion of the incision in bath water, or in a pool should wait until the skin is fully healed.
Can I put any lotion on the scar?
While the staples are still in, it is best not to apply anything to the incision, and to keep the wound clean and dry. Once the staples are out, you can use vitamin E cream to massage and loosen up the scar. Most patients find this beneficial and some feel it makes the scar less visible. Massaging the knee area with an anti-inflammatory or cortisone cream can also help reduce skin inflammation and tenderness after knee surgery.
When can I shower after knee replacement?
You can shower as soon as you want after surgery. The incision will be covered with a plastic dressing,\ and the nursing staff will assist you. If the wound dressing gets wet, you can change it after the shower and use a towel to dry the skin around the incision. Showering reduces the bacterial load on your skin. Once the staples are out and the skin is dry, you can soak the knee in a bath also, but do not soak the incision area in a bath before the staples are removed.
How long will I be off my feet after knee replacement?
You can put full weight on the replaced knee right after surgery. The therapist gets you up and walking the day after surgery. You will need the assistance of a walker or crutches, but putting weight on the knee and twisting is safe. Most patients are reasonably independent after four weeks, although individual recovery times vary.
Will I need a walker, crutches, cane or other assistive device?
Yes, you will likely require a walker for some time after knee surgery. If you have a walker, bring it with you to the hospital. If you do not have one, we can arrange for a walker while you are in the hospital.
Before surgery, you should pick up all throw rugs and secure extension/electrical cords at home, and make sure your furniture is arranged to allow you to use a walker safely, without the risk of falling. You can transition to a cane or crutches at any time you are comfortable.
I have pain and stiffness in the first few steps, and then the knee feels OK. Is this normal several weeks, or even months, after knee replacement?
Yes. Muscles, tendons and ligaments take time to stretch and accommodate after surgery. The pain that is worse after sitting and goes away with walking is called start-up pain, and can persist for a long time. These symptoms decrease as tissues heal. An anti-inflammatory medicine can help.
Will I have to learn how to walk again?
Considering that a prosthetic knee has no nerves and the arc of movement after knee surgery varies from before, many people feel like they must learn how to walk again. This is to be expected after knee replacement surgery. Take your time and do not rush the process. There is no point comparing your recovery to anyone else, since recovery is very individual and depends on many patient-specific variables. At some point in your recovery, the new knee begins to feel like a part of your body. Until then, it is true that you are, in a sense, learning to walk again.
How much therapy will I need?
You need a minimum of four weeks of therapy – usually at your home – with a visiting home health nurse. This person sees you about three times a week. Some patients need therapy after this four-week period, while others are already independent. If you need outpatient therapy, usually four to six weeks is sufficient. Once you learn basic knee exercises, you will be able to do them at home.
Maintaining a regular program of exercise and mild aerobic activity over the long-term is an excellent idea, and you will maximize the benefit of your new knee.
Can I kneel after having a knee replaced?
Yes, although it may take several months before you can do it comfortably. The reason is that the kneecap experiences heavy loads – loads that exceed your body weight – during knee bending. Soreness may keep you from kneeling after knee replacement surgery. You can safely kneel as soon as you are comfortable. You cannot damage the knee replacement by kneeling.
What happens if I do not get motion back in the knee quickly?
With minimally invasive surgery, lack of a tourniquet and minimal muscle disruption, knee motion returns very quickly after replacement surgery. In very few cases, if the knee is not gaining mobility, it may be necessary to manipulate the knee joint under an anesthetic to “fast-forward” you in therapy and break up early scar-formation in the knee joint. This is rarely necessary and performed only on individuals who form heavy scar tissue.
Why does scar tissue form in the knee joint?
Scar formation is normal after all operations. After knee replacement, knee movement usually overcomes scar formation inside the joint. Because of genetic factors and other variables, some patients form scars very quickly inside the knee joint. Such patients may need additional or more aggressive therapy, and such patients will find their recovery of knee mobility takes longer than others. This is normal, and again emphasizes no two patients recover alike since patient anatomy and physiology vary from person to person.
How much bending will I get in the knee joint after replacement?
Implants bend safely to 150 degrees, which is about the physiologic limit of human knee anatomy. Existing scar tissue, contractures of the knee joint, severity of arthritis, pain tolerance, motivation for exercise, body size and other variables profoundly affect how much mobility a person gets. For most patients, zero degrees of knee extension (bringing the knee out straight) and about 125 degrees of flexion (bending) are easily achieved; this is more than enough for almost all activities of daily living.
Do you use a machine to move the knee after surgery?
No benefit has been shown from the use of continuous passive motion (CPM) machines. Most surgeons use them now out of habit or because some patients prefer them. If you would like a machine to move your knee after surgery, let us know and we can discuss the option. However, it has been our experience that outcomes from knee replacement are just as good without these machines. CPM machines are never a substitute for using your own muscles and motivation to regain mobility.
Should I exercise after knee replacement?
Yes – a regular program of light aerobic exercise is best, with weight training added to the exercise regimen. Exercise is beneficial from many standpoints, and optimizes the outcomes of your knee replacement. Recommended exercises include walking, swimming, light aerobics, golf, treadmill, stair climbing, weight-training and elliptical exercise equipment. Check out a list of recommended exercises.
How soon will I be able to return to everyday activities?
Soon after surgery, you will begin to walk short distances in your hospital room and perform everyday activities. This early activity aids your recovery and helps your knee regain strength and movement. A nurse or therapist assists you as necessary.
Returning to regular activity in terms of walking, exercising and work vary greatly between patients; most patients return to their regular activities in six to 12 weeks.
How active can a person be after total knee replacement?
You can be as active as you want and carry as much weight as you can tolerate. Heavy impact exercises – such as basketball, football, soccer and tennis – are probably best avoided, since they contribute to increased prosthesis wear. Low-impact aerobics, bicycling, treadmills, swimming and similar exercises are fine. Climbing, hiking and other outdoor activities can be performed as tolerated.
Strength and endurance builds up over time. Modern total knee implants are very durable and designed to take repetitive impact loading for many decades, even in active and heavy patients.
When can I drive after knee replacement surgery?
For the left leg and an automatic transmission in your car, drive whenever you can comfortably sit in a car and have control of the operated leg. For the right leg (and left in the case of driving a car with a clutch), it takes about two to four weeks before you regain the confidence and control in the leg to drive. Of course, you should not drive if you are taking narcotics that make you sleepy or reduce alertness. Avoid driving any time comfort or pain is an issue.
How much can I lift?
You can lift as much as you are comfortable doing. Start out with small weights, and build up your tolerance. As long as the knee does not hurt, lifting weights is fine.
Can I ride horses after knee replacement surgery?
Yes, once your recovery is such that you are independent, strong, and comfortable, you can ride horses, ATVs and bicycles, with reasonable precautions that apply to each.
When can I go back to work after knee surgery?
The faster you get back to work, the better it is for you, psychologically and physically. We can accommodate your requests for time off work and your return to limited duties. Each individual and job situation is different. We work with you to expedite your transition back to your job. Some people with desk jobs have returned to limited work in two weeks after knee replacement; others have preferred to take several months off.
Can I climb ladders?
Yes, climbing ladders is fine as long as the knee is fully healed and your strength has returned.
When can I resume sex?
You can resume sex any time after knee surgery that you feel comfortable. Unless specifically instructed otherwise in very selected and unusual cases, there are no precautions to follow after knee replacement surgery.
When can I travel after surgery?
Whenever you feel comfortable, go ahead and travel by car or airplane. It is best to avoid the same seated position for over an hour, so try to get up and move around when possible. Otherwise, make sure to do ankle and calf exercises every hour to keep the blood pumping and avoid the possibility of blood clots forming. Prolonged sitting also causes leg swelling, so it is best to change position during travel if possible.
When can I drink alcohol after surgery?
Moderate, social alcohol use can be resumed anytime your appetite dictates. Avoid alcohol if your blood is too thin on the warfarin, and your warfarin dose is being held. Heavy alcohol use after any surgery is dangerous.
How long does it take for me to feel normal after a knee replacement?
While 80 to 90 percent of recovery is usually over by the first two months, the last 10 percent can linger. Even though patients can resume normal activities, the bone around the new implants keeps remodeling in response to the altered biomechanics. As a result, it can be up to two years or so before an artificial joint really feels like your own. It can take that long for the skeleton to accommodate the new knee, and feel normal.
Why is recovery after knee replacement said to be harder than after hip replacement?
There are four main reasons for this:
- After a hip replacement, very little exercise is necessary for recovery, since there is little risk of the hip getting stiff.
- Hip surgery can be done even less invasively than knee replacement using modern techniques.
- The hip has more muscles covering it, and fewer nerves.
- The hip joint is relatively simple, consisting of one kind of movement (ball and socket).
In contrast, the knee is a complex joint, relying on outside ligaments for support. These ligaments are stretched with every step. There is very little muscle cover around the knee, so any bump is felt in the joint. Finally, the knee tends to scar and stiffen quickly, and the joint must be moved actively to prevent this, and regain motion. For these reasons, recovery after hip replacement is typically a lot easier than recovery after knee replacement.
Tips on walking
Follow these tips for safe, effective walking following knee surgery:
- As you move forward, your knee and ankle bends, and your entire foot rests evenly on the floor. As you complete the step, your toe lifts off the floor and your knee and hip bend so you can reach forward for your next step. Remember, touch your heel first, then flatten your foot and then lift your toes off the floor.
- As your muscle strength and endurance improve, you may spend more time walking. You will gradually put more weight on your leg. You may use a cane in the hand opposite your surgery and eventually walk without an aid. Early on, it is best to moderate the exercise and avoid overdoing it.
- Proper walking is the best way to help your knee recover. At first, you will walk with a walker or crutches. Your surgeon or therapist will tell you how much weight to put on your leg. In most cases, full weight is safe right away.
- Stand comfortably and erect with your weight evenly balanced on your walker or crutches. Advance your walker or crutches a short distance; then, reach forward with your operated leg with your knee straightened so the heel of your foot touches the floor first.
- Walk as rhythmically and smoothly as you can. Don’t hurry. Adjust the length of your step and speed as necessary to walk with an even pattern.
- When you can walk and stand for more than ten minutes and your knee is strong enough so you are not carrying any weight on your walker or crutches (often about two to three weeks after your surgery), you can begin using a single crutch or cane. Hold the cane or crutch in the hand opposite the side of your surgery. You should not limp or lean away from your operated knee.
Tips on stairs
The ability to go up and down stairs requires strength and flexibility. At first, you will need a handrail for support and will be able to go only one step at a time. Always lead up the stairs with your good knee and down the stairs with your operated knee. Remember: “up with the good” and “down with the bad.” In other words, going up stairs, lead with the good (non-surgery) leg, and coming down stairs, put the bad (surgery) leg down first.
You may want to have someone help you until you have regained most of your strength and mobility. Stair climbing is an excellent strengthening and endurance activity.
Do not try to climb steps higher than the standard height (seven inches) and always use a handrail for balance. As you become stronger and more mobile, you can begin to climb stairs foot over foot.
Learn more about knee replacement surgery at MU Health Care.