TKRA (Total Knee Replacement Arthroplasty)

Overview

If your knee is significantly injured due to arthritis or injury, you may find it difficult to do simple activities like walking or climbing stairs. You may even have discomfort when sitting or lying down.

If nonsurgical therapies, such as drugs and walking aids, are no longer effective, you may wish to consider complete knee replacement surgery. Joint replacement surgery is a safe and successful technique for relieving pain, correcting leg deformity, and allowing you to return to regular activities.

Knee replacement surgery was performed for the first time in 1968. Improvements in surgical materials and procedures have substantially boosted its efficacy since then. Total knee replacements are one of the most effective medical treatments. According to the Agency for Healthcare Research and Quality, over 754,000 knee replacement surgeries were done in the United States in 2017.

Whether you are just starting to look at treatment choices or have already decided on total knee replacement surgery, this article will help you learn more about this beneficial technique.

 

Knee Anatomy

The knee is a hinge joint that is responsible for weight-bearing and movement. It consists of bones, meniscus, ligaments, and tendons.

The knee is designed to fulfill a number of functions:

• support the body in an upright position without the need for muscles to work.
• helps to lower and raise the body.
• provides stability.
• acts as a shock absorber.
• allows twisting of the leg.
• makes walking more efficient.
• helps propel the body forward.

Below, we will explain the basic components of knee anatomy.

• Bones:

The knee bones are made up of the femur (thigh bone), tibia (shin bone), and patella (kneecap). These bones are held in place by the knee joint.

The patella is a tiny, triangle-shaped bone located in the quadriceps muscle near the front of the knee. Because it is subjected to a significant lot of strain, it is lined with the thickest layer of cartilage in the body.

• Cartilage:

There are two types of cartilage in the knee:

• Meniscus: These are crescent-shaped discs that function as a cushion, or "shock absorber," allowing the bones of the knee to move without rubbing directly against each other. The menisci also include nerves that aid in balance and stability, as well as ensuring proper weight distribution between the femur and tibia. The knee has two menisci:

• medial – on the inner side of the knee, this is largest of the two.
• lateral – on the outer side of the knee.

• Articular cartilage: It is a thin, shining coating of cartilage present on the femur, the top of the tibia, and the rear of the patella. It absorbs trauma and allows bones to slide easily over one another.

 

• Ligaments: 

Ligaments are tough and fibrous tissues; they act like strong ropes to connect bones to other bones, preventing too much motion and promoting stability. The knee has four:

• ACL (anterior cruciate ligament) – prevents the femur from sliding backward on the tibia, and the tibia from sliding forward on the femur.
• PCL (posterior cruciate ligament) – prevents the femur from sliding forward on the tibia, or the tibia from sliding backward on the femur.
• MCL (medial collateral ligament) – prevents side to side movement of the femur.
• LCL (lateral collateral ligament) – prevents side to side movement of the femur.

 

• Tendons:

These strong rings of soft tissue give joint stability. They are comparable to ligaments in that they connect bone to muscle rather than bone to bone. The patellar tendon, which travels up the thigh and connects to the quadriceps, is the biggest tendon in the knee.

 

• Muscles:

Although not strictly part of the knee joint, the hamstrings and quadriceps are the muscles that strengthen the leg and aid in knee flexion.

The quadriceps are a group of four muscles that help to straighten the knee. The hamstrings are three muscles at the back of the thigh that allow you to bend your knee.

The gluteal muscles, commonly known as the glutes, are located in the buttocks and play a crucial role in knee posture.

 

• Joint capsule:

The joint capsule is a membrane bag that surrounds the knee joint. It is filled with a liquid called synovial fluid, which lubricates and nourishes the joint.

 

• Bursa:

There are approximately 14 of these small fluid-filled sacs within the knee joint. They reduce friction between the tissues of the knee and prevent inflammation.

 

How Does Partial Knee Replacement Differ from Total Knee Replacement?

The majority of arthroplasties target the whole knee joint, a procedure known as a complete knee replacement. However, some patients opt for a partial knee replacement.

To understand the difference, it helps to know the knee’s compartments, or sections. It has three:

• Inside (medial).
• Outside (lateral).
• Under the kneecap (patellofemoral/anterior).

The partial technique corrects only one portion. As a result, healthcare practitioners refer to it as unicompartmental replacement. All three components are addressed with a complete knee replacement. In general, only younger persons with problems in one leg benefit from partial knee replacement.

 

Causes of Knee Pain

Arthritis is the most prevalent cause of persistent knee pain and impairment. Although there are numerous varieties of arthritis, the three most common causes of knee pain are osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis.

• Osteoarthritis. This form of arthritis is caused by "wear and tear" over time. It mainly affects persons over the age of 50, although it can also affect younger people. The cartilage that cushions the bones of the knee goes away and softens. The bones then rub against one another, producing discomfort and stiffness in the knee
• Rheumatoid arthritis. The synovial membrane that covers the joint becomes inflamed and swollen in this condition. Chronic inflammation can harm cartilage, resulting in cartilage loss, discomfort, and stiffness. Rheumatoid arthritis is the most frequent type of an illness known as "inflammatory arthritis."
• Post-traumatic arthritis. This can happen after a significant knee injury. Fractures of the knee bones or rips in the knee ligaments can damage the articular cartilage over time, producing knee discomfort and reducing knee function.

 

When Surgery is Recommended?

Your doctor may propose knee replacement surgery for a variety of reasons. Individuals who benefit from complete knee replacement frequently have:

• Severe knee pain or stiffness that limits daily tasks such as walking, stair climbing, and getting in and out of chairs. It may be difficult to walk more than a few blocks without substantial discomfort, necessitating the use of a cane or walker.
• Day or night, moderate to severe knee discomfort when resting
• Chronic knee pain and edema that is not relieved by rest or medicine
• Knee deformity is defined as a bending in or out of the knee.
• Additional therapies, such as anti-inflammatory medicines, cortisone injections, lubricating injections, physical therapy, or other procedures, have failed to significantly improve.

 

The Orthopaedic Evaluation

An evaluation with an orthopaedic surgeon consists of several components:

• Medical history. Your orthopaedic surgeon will gather information about your general health and ask you about the extent of your knee pain and your ability to function.
• Physical examination. This will assess knee motion, stability, strength, and overall leg alignment.
• X-rays. These images help to determine the extent of damage and deformity in your knee.
• Other tests. Occasionally blood tests or advanced imaging, such as a magnetic resonance imaging (MRI) scan, may be needed to determine the condition of the bone and soft tissues of your knee.

Your orthopedic surgeon will go through the findings of your assessment with you and decide whether complete knee replacement is the best option for relieving pain and improving function. Other treatment options, including as drugs, injections, physical therapy, and surgery, will be evaluated and discussed.

Furthermore, your orthopedic surgeon will describe the possible risks and consequences of total knee replacement surgery, including those associated with the operation itself as well as those that can emerge over time following your surgery.

 

Preparing for Total Knee Arthroplasty

• Medical Evaluation:

If you decide to have total knee replacement surgery, your orthopaedic surgeon may request that you arrange a comprehensive physical examination with him or her several weeks before the procedure. This is required to ensure that you are in good enough health to have surgery and recover fully. Before surgery, many individuals with chronic medical issues, such as heart disease, may be assessed by a specialist, such as a cardiologist.

• Tests:

Several tests, such as blood and urine samples, and an electrocardiogram, may be needed to help your orthopaedic surgeon plan your surgery.

• Medications:

Inform your orthopaedic surgeon about any drugs you are currently taking. He or she will advise you on which drugs to discontinue and which to continue taking prior to surgery.

• Urinary Evaluations:

People who have had recent or regular urinary infections should be evaluated by a urologist prior to surgery. Before undergoing knee replacement surgery, older men with prostate disease should consider finishing all necessary therapy.

• Social Planning:

Although you will be able to walk with a cane, crutches, or a walker soon after surgery, you will want assistance with cooking, shopping, bathing, and laundry for several weeks.

If you live alone, a hospital social worker or discharge planner can assist you in making early plans to have someone assist you at home. They can also assist you in arranging for a brief stay in an extended care facility throughout your recovery if this is the best option for you.

• Home Planning:

Several modifications can make your home easier to navigate during your recovery. The following items may help with daily activities:

• Safety bars or a secure handrail in your shower or bath.
• Secure handrails along your stairways.
• A stable chair for your early recovery with a firm seat cushion (and a height of 18 to 20 inches), a firm back, two arms, and a footstool for intermittent leg elevation.
• A toilet seat riser with arms, if you have a low toilet.
• A stable shower bench or chair for bathing.
• Removing all loose carpets and cords.
• A temporary living space on the same floor because walking up or down stairs will be more difficult during your early recovery.

 

What Happens During Total Knee Arthroplasty?

You will be given anesthetic on the day of surgery to prevent pain during the procedure. A regional (spinal block) or general anesthesia will be administered. Your anesthesia experts will choose the best form of anesthesia for you.

Knee arthroplasty takes about an hour or two. The surgical team will:

• Make an incision (cut) in the knee area.
• Remove any damaged cartilage and bone.
• Place the knee implant and position it properly.
• Secure the implant into place using cement or without cement.
• Insert a piece of polyethylene (plastic) that creates a smooth, gliding surface between the metal parts of the implant.
• Close the incision.

 

Your Hospital Stay

If you are admitted to the hospital, you will most likely stay from one to three days.

• Pain Management:

You will have some discomfort following surgery. This is a normal component of the recovery process. Your doctor and nurses will attempt to lessen your discomfort, which will allow you to recuperate from surgery more quickly.

Medications are frequently recommended for short-term pain management following surgery. Opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and local anesthetics are among the medications available to assist control pain. Your doctor may prescribe a combination of these drugs to alleviate pain and reduce the need for opioids.

Although opioids can aid with pain relief after surgery, they are a narcotic and can be addicted. Opioid addiction and overdose have emerged as important public health concerns in the United States. It is critical to utilize opioids only as prescribed by your doctor. Stop using opioids as soon as your pain begins to improve. Consult your doctor if your pain does not improve within a few days following your procedure.

• Blood Clot Prevention:

Your orthopaedic surgeon may recommend one or more methods to reduce leg edema and avoid blood clots. Special support hose, inflated leg covers (compression boots), and blood thinners are examples of these.

Foot and ankle mobility is also suggested soon after surgery to improve blood flow in your leg muscles and avoid leg edema and blood clots.

• Physical Therapy:

Most patients can begin exercising their knees within a few hours of surgery. Soon after your operation, a physical therapist will teach you specialized exercises to strengthen your leg and restore knee mobility so that you may walk and do other typical everyday activities.

Your surgeon may employ a knee support that slowly moves your knee while you are in bed to recover mobility in your knee and leg. The equipment is referred to as a continuous passive motion (CPM) exercise machine. Some surgeons feel that by elevating your leg and working the muscles in your leg, a CPM machine reduces leg edema and increases blood circulation, however there is no proof that these machines enhance results.

• Preventing Pneumonia:

Patients with shallow breathing are prevalent in the early postoperative period. This is typically due to the effects of anesthetic, pain medicines, and increased sleep. This shallow breathing can cause a partial collapse of the lungs (known as "atelectasis"), making patients vulnerable to pneumonia. It is critical to take periodic deep breaths to assist prevent this. To urge you to take deep breaths, your nurse may offer you with a basic breathing equipment known as a spirometer.

 

Your Recovery at Home

The success of your surgery will depend largely on how well you follow your orthopedic surgeon's instructions at home during the first few weeks after surgery.

• Wound Care:

Stitches or staples will run along your wound, and a suture will be placed beneath your skin on the front of your knee. Several weeks following surgery, the sutures or staples will be removed. A suture placed beneath your skin will not need to be removed.

Avoid bathing the wound in water until it has healed completely. You can keep bandaging the wound to avoid discomfort 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 help your wound heal and to restore muscle strength.

• Activity:

Exercise is an important aspect of home care, especially in the first few weeks following surgery. You should be able to resume most typical daily activities after 3 to 6 weeks of surgery. For many weeks following surgery, some pain with exercise and at night is normal.

Your activity program should include:

• A graduated walking program — initially in your home and later outside — to slowly increase your mobility.
• Resuming other normal household activities, such as sitting, standing, and climbing 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.

 

Complications & Risks

Complications are uncommon after complete knee replacement. Only around 2% of individuals experience serious problems, such as a knee joint infection. Significant medical consequences, such as a heart attack or stroke, occur even less commonly. Complications may be increased by chronic diseases. Although these issues are infrequent, they might delay or limit full recovery.

Discuss your concerns thoroughly with your orthopaedic surgeon prior to surgery.

• Infection. Infections might develop in the wound or deep surrounding the prosthesis. It might happen days or weeks after your procedure. It might happen years later. Antibiotics are commonly used to treat minor wound infections. Major or deep infections may necessitate further surgery and the removal of the prosthesis. Any infection in your body has the potential to spread to your joint replacement.
• Blood clots. One of the most common consequences of knee replacement surgery is blood clots in the leg veins. If these clots break loose and move to your lungs, they can be fatal. Your orthopaedic surgeon will develop a preventative program for you, which may involve periodic leg elevation, lower leg exercises to promote circulation, support stockings, and blood-thinning medication.
• Implant problems. Despite advances in implant designs and materials, as well as surgical methods, implant surfaces and components may wear down and loosen. Furthermore, while an average of 115° of mobility is normally expected following surgery, scarring of the knee can develop on occasion, and motion may be more limited, particularly in individuals who had limited motion prior to surgery.
• Continued pain. A small number of patients continue to have pain after a knee replacement. This complication is rare, however, and most patients experience excellent pain relief following knee replacement.
• Neurovascular injury. While rare, injury to the nerves or blood vessels around the knee can occur during surgery.

 

Conclusion

With the use of metal or plastic implants, knee replacement, also known as knee arthroplasty, treats injured knee joints. It's a common operation that did beautifully at reducing arthritis- and injury-related pain and stiffness. After having a knee replacement and recovering from it, you can resume your regular activities and daily responsibilities.