Which Surgery Is Called Total Knee Arthroplasty?
Total knee arthroplasty is the procedure of replacing the damaged/worn knee joint with an artificial one that is usually made of metal and plastic.
This procedure is the final step in a process of degenerative lesions, due to osteoarthritis, rheumatoid arthritis, post-traumatic arthritis and other more rare causes that lead to the difficulty or even inability to perform simple activities such as walking or climbing stairs. Pain may also be present even while sitting.
If symptomatic treatment and walking aids are no longer effective and the result is deterioration in quality of life, you may need to consider knee replacement surgery (total knee arthroplasty).
If you are considering a total knee arthroplasty or have already decided with your orthopedic surgeon to undergo knee replacement surgery, the following information will help you to understand more about this valuable procedure.
Knee Anatomy
The knee is the largest joint in the body. Normal knee function is required to perform most of the daily activities. The knee is composed of the lower end of the femur (thigh) that rotates on the upper end of the tibia, and the patella, which slides into a groove at the end of the thigh. The femur and tibia are connected by major ligaments (Anterior cruciate ligament, Posterior cruciate ligament, Medial collateral ligament, Lateral collateral ligament) that, together with the muscles that connect the parts of the knee, provide stability to the joint. The long femoral muscles and to a lesser extent the gastrocnemius are responsible for the movement and support of the knee.
The contact surfaces of these three bones are covered with articular cartilage, a smooth substance that reduces friction between the bones and facilitates movement in the joint.
All other surfaces of the knee joint are covered by a fine smooth tissue called synovial membrane or bursa. This membrane produces a special fluid (the synovial fluid) that lubricates the knee and greatly reduces friction on a healthy knee.
Normally, all of these components work in harmony. But diseases or injury can destroy this balance, resulting in pain, muscle weakness, and reduced function.
Common causes of knee pain and loss of function
The most common cause of chronic knee pain and disability is arthritis. Osteoarthritis, rheumatoid arthritis and post-traumatic arthritis are the most common forms.
- Osteoarthritis usually occurs in people over 50 years old and often in people with a family history of arthritis. The cartilage that covers the bones of the knee softens and is destroyed. The bones rub against each other, causing pain and stiffness.
- Rheumatoid arthritis is a disease in which the synovial membrane is thickened and inflamed, producing too much synovial fluid that dilates the joint. This chronic inflammation can damage the cartilage and eventually cause its degeneration, resulting in pain and stiffness.
- Post-traumatic arthritis can be a result of serious knee injury. A knee fracture or severe knee ligament injury changes the biomechanics, causing increased loads that over time cause damage to the articular cartilage, leading to pain and limitation of joint function.
Is Total Knee Arthroplasty the Best Solution for You?
Undergoing total knee arthroplasty is a decision you will make, taking into account your needs, your family, your physician and your orthopedic surgeon. Your physician may refer you to an orthopedic surgeon for a detailed evaluation.
So, he will determine if you could benefit from this surgery. Alternatives to total knee arthroplasty that your orthopedic surgeon may discuss with you include arthroscopy, unicompartmental knee arthroplasty or knee osteotomy.
The reasons you can benefit from total knee arthroplasty usually include:
- Severe knee pain that restricts daily activities, including walking, climbing stairs and standing or sitting on a chair. Walking is limited to short distances before pain forces you to stop, which is usually less than 500 meters. The pain requires from you to use a walking cane or stroller.
- Continuous severe knee pain affecting night sleep
- Chronic inflammation of the knees and edema that do not improve with rest or medications
- Knee deformation
- Knee stiffness: inability to bend and straighten your knee
- Inability to achieve pain relief with non-steroidal anti-inflammatory drugs. These medications, including aspirin and ibuprofen, are often most effective in the early stages of arthritis. Their effectiveness in controlling knee pain varies greatly from person to person. These medications may be less effective for patients with advanced arthritis.
- Inability to tolerate medicines or complications from their use
- Failure to improve with other treatments such as injections of hyaluronic acid, physiotherapy or other surgical procedures.
Most patients undergoing total knee arthroplasty are 60 to 80 years old. However, orthopedic surgeons evaluate each patient individually. The recommendations for surgery are based on the patient’s pain and subsequent disability, not age.
Total knee arthroplasty has been successfully performed at all ages, from young patients with juvenile arthritis to the elderly with degenerative arthritis.
Orthopedic evaluation
An orthopedic evaluation consists of several parameters:
- A medical history in which your orthopedic surgeon collects information about your general health status. The physician will ask you about the severity of knee pain and your ability to perform activities
- A physical examination to evaluate knee movement, stability, strength and overall foot alignment
- Radiographs to determine the extent of injury and deformity in your knee
- Occasionally blood tests, MRI (magnetic resonance imaging), or bone scintigraphy may be required to determine the condition of your bones and soft tissues.
Your orthopedic surgeon will evaluate the results of your clinical and laboratory tests. He will then discuss with you whether or not total knee arthroplasty (knee replacement) would be the best way to relieve your pain and improve your functionality. Other treatment options – including medications, injections, physiotherapy or other types of interventions – will also be discussed and considered.
Your orthopedic surgeon will also explain the potential risks and complications of total knee arthroplasty, including those that may occur during surgery and in the postoperative course.
Realistic Expectations about Knee Replacement Surgery (Total Arthroplasty)
An important factor in deciding whether or not to undergo total knee arthroplasty is to realize what the surgery can and cannot offer.
More than 90% of people undergoing total knee arthroplasty experience a significant reduction in knee pain, as well as improvement in their ability to perform the common daily activities of their lives. But total knee arthroplasty will not make you a great athlete or allow you to do more than what you did before you develop arthritis.
Dangerous Post-Surgery Activities:
Running – sports with physical contact – sports with jumps – intense aerobic exercise
Activities beyond the post-surgery recommendations:
Intense walking – skiing – tennis – systematic lifting of more than 15 kg – systematic aerobic stepping
Post-surgery activities:
Leisure walking – Swimming – Golf – Driving – Bike Rides – Dance – Ordinary stair climbing
After surgery, you will be encouraged to avoid some types of activities for the rest of your life.
Within normal use and activity range, any prosthesis develops some wear on its plastic parts. Excessive activity or weight can accelerate this normal wear and tear, causing loosening and pain. With the appropriate modification of activities, total knee arthroplasty materials can last for many years.
Surgery
Medical evaluation
Before surgery, the orthopedic surgeon will examine the condition of the skin and determine preoperative examination. Preoperative screening usually includes microbiological blood and urine tests, chest x-rays, blood donation to ensure possible transfusion, screening for possible modification or discontinuation of prescribed medicines before surgery (salospir, plavix, etc.) and tests by other medical specialties, if required by patient history.
It is also important to provide help at home, as the patient will initially have a reduced self-service ability. It is also recommended to provide appropriate aids that make the initial movement and living safer.
Some indicative measures are:
- defining a living space on a certain floor, as initially ascending/descending stairs will be difficult
- fixed handles in the toilet and bathroom
- toilet lift
- removal of all loose carpets, cable ropes
- a high chair with a fixed back and a footstool for periodic lifting of the legs
The surgery
After completing your preoperative check-up and hospitalization you will be taken to the operating room where the anesthesiologist will administer anesthetic drugs after a brief discussion of your medical history. The most common types of anesthesia are general anesthesia in which you are asleep throughout the procedure and spinal or epidural anesthesia in which you are not asleep but your feet are numbed. The anesthesiologist’s team will determine which type of anesthesia will be best for you.
The surgery lasts for approximately 2 hours. Your orthopedic surgeon will remove the damaged cartilage and bone and then insert the new metal and plastic parts to restore alignment and function of your knee.
Many different types of designs and materials are currently used in total knee replacement surgery, almost all of which consist of three parts: the femur (usually made of metal), the tibia (made of durable plastic usually fixed on a metallic disc), and the patella, also made of plastic, (many surgeons choose to remove the damaged patellar cartilage without implant placement).
After surgery, you will be taken to the recovery room, where you will remain for 1 to 2 hours while your anesthesia recovery will be monitored. After you wake up, you will be taken to your hospital room.
Hospitalization
You will most likely stay at the clinic for several days. After surgery, you will feel some pain, but medications will be provided to make your recovery as comfortable as possible. Since pain management is an important part of your recovery, you should inform your surgeon in case postoperative pain is significant. Movements of the operated leg begin immediately after surgery and the first steps are usually attempted the first day after surgery with the help of a physiotherapist and in accordance with provided guiding.
To avoid lung congestion and possible atelectasis after surgery, you must breathe deeply and cough frequently to cleanse your lungs (breathing exercises).
Your orthopedic surgeon may recommend one or more measures to prevent blood clots and reduce edema. Such are elastic bandages, antithrombotic stockings and administration of antithrombotic drugs.
To restore movement of your knee and foot, your surgeon may use a device called a CPM.
Complications
The rate of complications after total knee arthroplasty is low and over 90% of patients are very satisfied with the results. Although the procedure is performed in aseptic conditions and you are covered peri-operatively with antibiotics, a small percentage of patients 1-2% develop bacterial infection. This is a complication that can lead to one or more measures to fight the infection and the final result may not be so good.
Another potentially serious complication is thrombosis. Despite rapid mobilization, the use of antithrombotic stockings and the administration of antithrombotic drugs, thrombosis occurs quite frequently. The vast majority is dealt with by the body itself without causing significant problems; however 1-2% of thrombosis cases can be severe with significant expansion and possibly detachment of thrombus moving to the lungs or more centrally causing potentially very serious complications, such as pulmonary embolism.
There is still stress in the body after surgery. This condition may bring fourth existing problems that were not manifested in the low-functioning state that typically characterizes patients in the preoperative period.
The risks of anesthesia should be added to the above, plus about 4% of patients who post-operatively quickly return to their painful exercise program and ultimately end up with a painful and stiff knee.
In spite of the discouraging things mentioned above, total knee arthroplasty has consistently over 90% and sometimes over 95% satisfied patients, making it one of the most successful surgical interventions of modern orthopedics, providing relief and solution to chronic problems caused by the degeneration of the knee joint.
Discuss your concerns in detail with your orthopedic surgeon prior to surgery.
