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A total knee replacement is a procedure in which the doctor removes an arthritic knee joint and replaces it with an artificial one. This procedure may be done when Arthritic knee joint has become painful or is not working well even with other conservative management techniques. One of the most important orthopaedic surgical advances of the twentieth century, knee replacement was first performed in 1968. Improvements in surgical materials and techniques since then have greatly increased its effectiveness.

Working of a Normal Knee: The knee joint is the largest joint in the body involved in day to day activities. It is made up of the lower end of the thigh bone (femur), which rotates on the upper end of the shin bone (tibia), and the knee cap (patella), which slides in a groove on the end of the femur. Ligaments attach the femur to tibia to provide stability. A shock absorbing structure called us meniscus is present in between the two bones. The long thigh muscles mainly quadriceps and hamstrings give the knee strength.

The joint surfaces where these three bones touch are covered with a smooth glistening structure called as articular cartilage. This  smooth substance that cushions the bones, enables them to move easily without much friction. Wearing out of this structure results in pain and a disorganized movement – a condition called as arthritis.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 less function.

Types of Arthritis: Arthritis is the most common cause of chronic knee pain and disability. Osteoarthritis, rheumatoid arthritis and traumatic arthritis are its most common forms.

Osteoarthritis is a degenerative condition that usually occurs after the age of 50 and often in an individual with a family history of arthritis. Certain racial groups have a propensity of this type of arthritis which is thought to be due to biomechanical alteration in the knee joint owing to the shape of their leg and the way in which the weight is transmitted across the joint. In this condition, 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 an auto immune  disease in which the synovial membrane becomes thickened and inflamed, producing too much synovial fluid that over-fills the joint space. The content of the synovial fluid is also strongly inflammatory in nature. 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's ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function. Common fractures include tibial condyle fractures and common ligament injuries include anterior cruciate ligament (ACL) tear.

Common Reasons for which Knee replacement is carried out: Some of the most common reasons for which this replacement is carried out are:

  • Severe knee pain that limits your everyday activities, including walking, going up and down stairs, and getting in and out of chairs. You may find it hard to walk more than a few blocks without significant pain and you may need to use a cane or walker. Failure to obtain pain relief from non-steroidal anti-inflammatory drugs is considered one of the strongest indication. These medications, including aspirin and ibuprofen, often are most effective in the early stages of arthritis. Their effectiveness in controlling knee pain varies greatly from person to person. These drugs may become less effective for patients with severe arthritis. Moreover a prolonged use of these agents has an adverse in functioning of many vital organs including Liver and Kidneys.
  • Moderate or severe knee pain while resting, either day or night
  • Chronic knee inflammation and swelling that doesn't improve with rest or medications
  • Knee deformity--a bowing in or out of your knee
  • Knee stiffness--inability to bend and straighten your knee

Age at which surgery can be performed: Most patients who undergo total knee replacement are age 60 to 80, but orthopaedic surgeons evaluate patients individually. Recommendations for surgery are based on a patient's pain and disability, not age. Total knee replacements have been performed successfully at all ages, from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis.

Tests and examination required before surgery: This comprises of two parts- a general evaluation that is required before administering anaesthesia for any surgery and an orthopaedic evaluation. The orthopaedic evaluation consists of several components:

  • A medical history about your general health and the extent of your knee pain and your ability to function
  • A Clinical examination to assess knee motion, stability, strength and overall leg alignment
  • X-rays to determine the extent of damage and deformity of the knee and to do a preoperative planning.
  • Occasionally blood tests, a Magnetic Resonance Image (MRI) or a bone scan may be needed to determine the condition of the bone and soft tissues of your knee.

Alternative treatments for Arthritis: Total knee replacement is considered ideal for the late or severe stages of disease. Early stages may respond to following line of treatment –

  • using acetaminophen, aspirin, or other NSAID drugs for pain and inflammation.
  • Physiotherapy- exercises to strengthen the quadriceps muscle.
  • limiting activity (avoid squatting, stairs, and heavy lifting) and use a walking aid, such as a cane or walker.
  • Using ice or heat to reduce pain and swelling.

Preparing for the surgery: You wouldn't think of running a marathon without going into training beforehand. Not only would you exercise to improve your physical endurance and strength, but you also would prepare psychologically for the grueling test ahead. In its own way, joint replacement surgery is no less challenging for your body and mind. To go the distance successfully, you need to be ready mentally as well as physically. Using some pre-op prep techniques can help you relax before your joint replacement surgery.

Organizing your life before total joint replacement surgery is essential to eliminating your stress before and after surgery. After you’ve set up your home, arranged for a caregiver and chosen a qualified surgeon you feel comfortable with, do you still have fears and doubts about the outcome of your joint replacement surgery?

It’s very common to experience these nagging fears. In fact, what you're feeling is more the rule than the exception. People tend to have certain fears about any major surgery, One is fear of the surgery process itself and the possibility that something might go wrong during the operation. Another is fear of pain, and of not being able to do all the things you want to do after the joint replacement surgery. Whether a person acknowledges having such fears or not, virtually everyone thinks about these things before going into surgery.

It's important to face your fears realistically and acknowledge your concerns about joint replacement surgery. Keep in mind that your decision to have total joint replacement was an educated, well thought out one. Focusing on the benefits of the surgery will help you overcome some of your fears and hesitations.

Mentally Preparing for Joint Replacement Surgery.

Several kinds of relaxation techniques may be helpful for joint replacement surgery patients. These include:

  • Breathing exercises— Using awareness and conscious control over breathing to bring about relaxation.
  • Meditation— Relaxing the body and calming the mind by focusing on a repeated word or sound.
  • Cue-controlled relaxation— Learning to use a specific cue as a signal to illicit the relaxation response.
  • Imagery— Using the imagination to bring about changes in thoughts, feelings, and physical responses.
  • Self-hypnosis— Creating within yourself a state of highly focused attention and acute awareness.
  • Music therapy— Using music in a prescribed way to foster relaxation or distract yourself from pain.

Realistic Expectations About Knee Replacement Surgery

Before undergoing total knee replacement surgery it is vital to understand what the procedure can do for you and what it cannot.

Most 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 won't 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. However you can carry out brisk walking, climb stairs up and down, do swimming, play golf, do a bit of dancing and cycling.

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.

Surgery:

Patients are usually admitted to the hospital on the evening before the surgery. After admission, a pre anaesthetic check up is carried out by a member of the anesthesia team. The most common types of anesthesia is a combined spinal and epidural anesthesia, in which you are awake but your legs are anesthetized. The epidural catheter may also be kept after surgery also, this is to keep you pain free in the postoperative period. The anesthesia team may however determine which type of anesthesia will be best for you with your input.

The procedure itself takes about two hours. The Surgeon will put a tourniquet above your knee and make a cut from above the kneecap to below it. The knee joint is then exposed , the muscles and other tight structures connected to it are loosened, and t the kneecap is turned out of its place. During the procedure the damaged cartilage and bone is removed and then position the new metal and plastic joint surfaces to restore the alignment and function of knee is carried out. Many different types of designs and materials are currently used in total knee replacement surgery. Nearly all of them consist of three components: the femoral component (made of a highly polished strong metal), the tibial component (made of a durable plastic often held in a metal tray), and the patellar component (also plastic). The choice of company largely depends on surgeon, based on his experience with the given design. The doctor will cement the artificial replacement parts to the remaining ends of the bones. The doctor may cement an artificial surface to the back of the kneecap. He or she will try to remove any excess cement and place a tube in the knee to drain any extra fluid from the cut. The doctor will close the cut and put a bandage and a splint around your knee.

You may require a blood transfusion. The hospital will either use your donated blood or it will use matched blood.

 

 

After Surgery:

 

After surgery, you will be moved to the recovery room, where you will remain for one to two hours while your recovery from anesthesia is monitored. After you awaken, you will be taken to your hospital room.

You will most likely stay in the hospital for several days. After surgery, you will feel some pain, but medication will be given to you to make you feel as comfortable as possible. Walking and knee movement are important to your recovery and will begin immediately after your surgery.

To avoid lung congestion after surgery, you should breathe deeply and cough frequently to clear your lungs.

Your orthopaedic surgeon may prescribe one or more measures to prevent blood clots and decrease leg swelling, such as special support hose, inflatable leg coverings (compression boots) and blood thinners.

To restore movement in your knee and leg, your surgeon may use a knee support that slowly moves your knee while you are in bed. The device, called a continuous passive motion (CPM) machine, decreases leg swelling by elevating your leg and improves your venous circulation by moving the muscles of your leg.

Foot and ankle movement also is encouraged immediately following surgery to increase blood flow in your leg muscles to help prevent leg swelling and blood clots. Most patients begin exercising their knee the day after surgery. A physical therapist will teach you specific exercises to strengthen your leg and restore knee movement to allow walking and other normal daily activities soon after your surgery.

 

Possible Complications After Surgery

Although every effort is taken to prevent them, any surgery be it minor or major can have some potential complications. The best approach towards them is to understand them, and keep faith in your healthcare provider. A positive attitude towards a problem helps it solve better.The complication rate following total knee replacement is low. Serious complications, such as a knee joint infection, occur in less than 2 percent 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 your full recovery.

Risks of Anaesthesia: Risks from local and regional anesthesia include:

  • You may feel some minor discomfort because the anesthetic may not numb the area enough.
  • You may have an allergic reaction to the anesthetic, causing fever, nausea, vomiting, swelling, hives, or trouble breathing.
  • You may have long-term damage to the nerves.
  • You may have trouble breathing because the anesthetic can affect the respiratory system.
  • Rarely, you may react by having seizures, dizziness, loss of consciousness, or cardiac arrest.

Risks from general anesthesia include:

  • After the anesthesia, you may have nausea and vomiting, sore throat, and muscle pain.
  • You may have stress on the heart.
  • You may have an irregular heartbeat (arrhythmia).
  • You may have confusion after the anesthesia.
  • In rare cases, you may have a heart attack, stroke, or brain damage, which could result in death.

Deep Vein Thrombosis: A great many patients who have joint replacement surgery may have some form of DVT after their surgery. It is a potentially serious condition that doctors monitor closely. Today, with preventive measures, patient education, medicines and devices like compression stockings, the condition is managed very effectively to reduce the likelihood of complications.

DVT is the formation of a blood clot in one of the deep veins of the body, particularly in the leg or pelvis. According to the Arthritis Foundation, anyone who is sedentary is at some risk for DVT – even passengers in airplanes. Its severity can range from an unnoticeable incident to a very serious concern. The good news is that it is a condition that can be monitored and managed closely to reduce the likelihood of problems.

DVT in some form is very common in patients having joint replacement surgery. Total joint replacement heightens the body’s tendency for clotting. In addition, when the leg is manipulated during surgery there may be irritation to the walls of the major blood vessels in the leg. During and after surgery the leg is not used much and, therefore, the normal blood flow rate is decreased and the risk of DVT is increased.

The main goals in treating DVT are to:

  • stop the clot from getting bigger.
  • prevent the clot from breaking off in your vein and moving to your lungs.
  • reduce your chance of having another blood clot.

There are several medications used to prevent or treat DVT. Blood-thinning medications are used to prevent clots and to stop clots from getting bigger. These can either come as a pill (example: warfarin or coumadin) or as an injection. To help dissolve clots that have already formed, a different type of medicine called thrombolytics is used, usually only in advanced cases. These are just a few of the medicines doctors use to help prevent and treat DVT.

You may be prescribed compression devices to reduce the swelling and help manage DVT. For example, compression stockings are worn on the legs from the arch of the foot to just above or below the knee. These stockings are tight at the ankle and become looser as they go up the leg. This causes a gentle pressure up your leg to reduce the DVT risk.

Implant wear: 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 degrees of motion is generally anticipated after surgery, scarring of the knee can occasionally occur and motion may be more limited. This is particularly true in patients with limited motion before surgery. Finally, while rare, injury to the nerves or blood vessels around the knee can occur during surgery.

Infection: Surgical site infection is one of the most important consideration while performing total joint arthroplasty. Although it is impossible to completely eliminate the possibility of infection at even the worlds most advanced centre, Most hospitaluse systematic and realistic approach to reduce the risk of surgical site infections with the awareness that the risk of infection is influenced with characteristic of patient, operation, personnel and health care facility. To monitor all this and ensure that the entire system works towards preventing infection, an infection control committee that is comprised of microbiologist, consultants, members of administration and pharamacist keeps a watch over the entire functioning.

 

Most of the surgical site infections originate from the patients endogenous flora and to reduce the risk, the patient is advised a dental check up, a shower before surgery and a thorough pre surgical preparation including a two time scrubbing procedure (8 min each in ward as well as OR) and an antiseptic Prep in the OR. During surgery, special precautions are taken to ensure that there is no exogenous contamination of the patient's tissue or sterile surgical instruments. Other measures include preoperative antibiotic prophylaxis, careful surgical technique, adequate OR ventilation. Even the postoperative stay risk is taken care of with fumigation of postoperative rooms and use of clean sterilized bed sheets.

 

After Discharge: The success of your surgery also will depend on how well you follow your orthopaedic surgeon's instructions at home 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 on the front of your knee. The stitches or staples will be removed several weeks after surgery. A suture beneath your skin will not require removal.

Avoid soaking the wound in water until the wound has thoroughly sealed and dried. The wound may be bandaged to prevent irritation from clothing or support stockings.

Diet

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.

Activity

Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal activities of daily living within three to six weeks following surgery. Some pain with activity and at night is common for several weeks after surgery. Your activity program should include:

  • A graduated walking program to slowly increase your mobility, initially in your home and later outside
  • Resuming other normal household activities, such as sitting and standing and walking up and down stairs
  • Specific exercises several times a day to restore movement and strengthen your knee. You probably will be able to perform the exercises without help, but you may have a physical therapist help you at home or in a therapy center the first few weeks after surgery.

Driving usually begins when your knee bends sufficiently so you can enter and sit comfortably in your car and when your muscle control provides adequate reaction time for braking and acceleration. Most individuals resume driving about four to six weeks after surgery.

Avoiding Problems After Surgery

Blood Clot Prevention

Follow your orthopaedic surgeon's instructions carefully to minimize the potential of blood clots that can occur during the first several weeks of your recovery.

Warning signs of possible blood clots in your leg include:

  • Increasing pain in your calf
  • Tenderness or redness above or below your knee
  • Increasing swelling in your calf, ankle and foot

Warning signs that a blood clot has traveled to your lung include:

  • Sudden increased shortness of breath
  • Sudden onset of chest pain
  • Localized chest pain with coughing

Notify your doctor immediately if you develop any of these signs.

Preventing Infection

The most common causes of infection following total 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 knee replacement and cause an infection.

For the first two years after your knee replacement, you must take preventive antibiotics before dental or surgical procedures that could allow bacteria to enter your bloodstream. After two years, talk to your orthopaedist and your dentist or urologist to see if you still need preventive antibiotics before any scheduled procedures.

Warning signs of a possible knee replacement infection are:

  • Persistent fever (higher than 100 degrees orally)
  • Shaking chills
  • Increasing redness, tenderness or swelling of the knee wound
  • Drainage from the knee wound
  • Increasing knee pain with both activity and rest

Notify your doctor immediately if you develop any of these signs.

Avoiding Fall:

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, hand rails or 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.

The New Knee and how is it 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 nearly fully straighten the replaced knee and to bend the knee sufficiently to go up and down 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 these are minor, compared to the pain and limited function they experienced prior to surgery.

Your new knee may activate metal detectors required for security in airports and some buildings. Tell the security agent about your knee replacement if the alarm is activated.