Total knee replacement

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.

 

What is Total knee replacement (TKR)

 

Total knee arthroplasty (TKA) or total knee replacement (TKR) is a popular orthopedic procedure that includes replacing the articular surfaces of the knee joint (femoral condyles and tibial plateau) with smooth metal and highly cross-linked polyethylene plastic. TKA is intended to enhance the quality of life of people with end-stage osteoarthritis by lowering pain and boosting function. In industrialized nations, the frequency of TKA procedures has grown, with younger patients having TKA.

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.

TKA was once thought to be a surgery reserved for elderly, low-demand patients, but it is now becoming increasingly popular in younger patient populations. Annual primary TKA volume in the US Medicare population alone grew by 161.5% between 1991 and 2010, from more than 93,000 to more than 226,000 cases.

Osteoarthritis is the most prevalent reason for a primary knee replacement, or TKA. Osteoarthritis damages the cartilage of the joint, rendering it incapable of absorbing shock. Gender, an increased BMI, a history of knee injuries, and comorbidities are all risk factors for knee osteoarthritis. The most common symptom of individuals with knee osteoarthritis is pain. Pain is a subjective sensation that is mediated by peripheral and central brain systems that are influenced by neurochemical, environmental, psychological, and hereditary variables.

Total knee arthroplasty is more typically done on women and elderly people. The bulk of TKA operations were done on women in both the United States and the United Kingdom. With a growing incidence of younger TKA patients under the age of 60, dramatic increases in TKA procedures are expected.

 

Knee Anatomy

The knee is the body's biggest joint, and having healthy knees is necessary for most daily tasks. Normal anatomy of the knee. These components collaborate in a healthy knee to provide smooth, natural function and mobility.

The knee is made up of the thighbone's lower end (femur), the shinbone's higher end (tibia), and the kneecap (patella). The ends of these three bones are protected by articular cartilage, a smooth material that allows the bones to move freely within the joint.

Between the femur and tibia lie the menisci. These C-shaped wedges function as "shock absorbers," cushioning the joint. Large ligaments connect the femur and tibia and give stability. The knee is supported by the lengthy thigh muscles.

A thin coating called the synovial membrane covers all of the remaining surfaces of the knee. In a healthy knee, this membrane secretes a fluid that lubricates the cartilage, lowering friction to practically nil.

Normally, all of these elements act in tandem. However, sickness or injury can upset this balance, causing discomfort, muscular weakening, and decreased function.

 

Who is offered knee replacement surgery?

Because a knee replacement involves significant surgery, it is often advised only when alternative therapies, such as physiotherapy or steroid injections, have failed to relieve pain or improve mobility.

You may be offered knee replacement surgery if:

• You have severe pain, swelling and stiffness in your knee joint and your mobility is reduced
• Your knee pain is so severe that it interferes with your quality of life and sleep
• Everyday tasks, such as shopping or getting out of the bath, are difficult or impossible
• You're feeling depressed because of the pain and lack of mobility
• You cannot work or have a social life

You must also be in good enough health to handle both a major operation and the subsequent recuperation.

 

Characteristics of severe arthritis of the knee Pain

The most visible sign of knee arthritis is pain. Most patients' knee pain worsens gradually over time, however there are instances when the symptoms become severely severe. Weight-bearing and activities nearly often aggravate the discomfort. Knee pain might develop severe enough in some persons to impede even ordinary daily activities.

 

Stiffness

Certain kinds of arthritis cause morning stiffness. Patients who have morning knee stiffness may find some improvement in knee flexibility during the day. Rheumatoid arthritis sufferers may have more frequent morning stiffness than people with Osteoarthritis.

 

Swelling and warmth

Arthritic patients may experience swelling and warmth in their knees. If the edema and warmth are significant and are accompanied by severe discomfort, inability to bend the knee, and trouble bearing weight, such symptoms may indicate an infection. Such serious symptoms necessitate prompt medical intervention.

 

Location

The knee joint is divided into three "compartments" that might be affected by arthritis. Most patients have symptoms as well as X-ray results that indicate involvement of two or more of these compartments, such as discomfort on the lateral side and behind the kneecap. Patients who have arthritis in two or all three compartments and opt to have surgery will almost always have complete knee replacement.

 

Preparing for knee replacement surgery

Before you walk into the hospital, learn everything you can about your procedure. Your hospital should include textual materials as well as films.

Maintain as much activity as possible. Your rehabilitation will be aided if you strengthen the muscles around your knee. Continue to conduct light activity, such as walking and swimming, if possible, in the weeks and months leading up to your surgery. You may be sent to a physiotherapist, who will provide you with beneficial exercises.

 

Technical details of total knee replacement

To prevent infection, total knee replacement surgery begins with a sterile preparation of the skin above the knee. This is followed by the use of a tourniquet to prevent blood loss during the procedure.

Following that, a well-positioned skin incision is made down the front of the knee, often 6"-7" in length, though this varies depending on the patient's size and the intricacy of the knee condition, and the knee joint is evaluated.

Following that, specialized alignment rods and cutting jigs are used to remove enough bone from the femur (thigh bone), tibia (shin bone), and patella (kneecap) to facilitate insertion of the joint replacement implants. Proper implant size and alignment, as well as ligament balance, are all crucial for normal post-operative function and pain alleviation.

 Again, these stages are difficult, and substantial experience in total knee replacement is necessary to ensure that they are performed consistently, case after case. Provisional (trial) implant components are used to ensure that they fit well against the bones and are properly positioned. At this point, excellent function is confirmed, including complete flexion (bend), extension (straightening), and ligament balance.

Finally, saline solution is used to clean the bone before the joint replacement components are bonded into place using polymethylmethacrylate bone cement. Stitches and staples are used to seal the surgical wound.

 

Anesthetic

Total knee replacement surgery can be done using epidural, spinal, or general anaesthetic. We normally choose epidural anesthetic because it can give up to 48 hours of post-operative pain relief and allows for faster, more pleasant physical therapy progress.

 

Length of total knee replacement surgery

There are no two knee replacements that are similar, and surgical timeframes vary. A normal complete knee replacement procedure takes roughly 80 minutes.

 

Pain and pain management

We utilize an epidural catheter (a very thin flexible tube put into the lower back during surgery) to treat post-operative discomfort wherever possible. This gadget is comparable to those used to assist women give birth more easily. We leave the epidural in place for two days following surgery as long as it is giving adequate pain relief. After the epidural is withdrawn, pain medications typically offer enough pain relief. Patients who have had a successful epidural should anticipate to walk with crutches or a walker and move their knee through a near-complete range of motion the day following surgery.

 

Use of medications

Following hospital release, most patients will take oral pain medications—usually Percocet, Vicoden, or Tylenol—for one to three weeks, mostly to aid with physical therapy and home exercises for the knee.

Following this treatment, aggressive rehabilitation is preferred, and a high degree of patient desire is required to get the best potential outcome. Oral pain relievers aid in this process in the weeks following surgery.

Most patients require narcotic pain medication for 2 to 6 weeks following surgery. Patients should not drive while on these drugs.

 

Post-TKA Surgery

TKA surgery usually takes 1 to 2 hours. Within 24 hours of surgery, the majority of patients begin physiotherapy throughout their hospital stay. Before being discharged from the hospital, range of motion and strengthening exercises, cryotherapy, and gait training are usually started, and a home exercise regimen is given. Accelerated physiotherapy regimens have been shown to minimize the time of stay in an acute hospital.

Patients are often discharged from the hospital after a few days and undergo follow-up physiotherapy in an outpatient or home care environment within one week of discharge.

Individuals who have undergone primary TKA surgery with cemented prosthesis using a typical surgical method are advised to follow the post-operative protocols for assessment and care. The directions of surgeons should always be followed.

 

Effectiveness of total knee replacement

Current research reveals that when complete knee replacements are performed effectively in well chosen individuals, the vast majority of patients achieve success and the implant serves the patient well for many years.

According to several studies, 90-95 % of total knee replacements are still working normally 10 years following surgery. Most patients can walk without a cane, climb stairs, and get out of chairs normally, and they can resume their chosen degree of recreational activity.

If a complete knee replacement requires revision (re-operation) in the future, it can nearly always be done successfully. However, the outcomes of revision knee replacements are often worse to those of first-time knee replacements.

There is strong evidence that the surgeon's experience corresponds with the result of total knee replacement surgery. It is preferable to have the initial operation performed by a surgeon with experience in this field, such as a fellowship-trained surgeon with a knee replacement practice. Surgeons with this degree of expertise have been demonstrated to have fewer problems and better outcomes than surgeons with less experience. As a result, it is critical that the surgeon executing the approach be not just a skilled orthopedic surgeon but also an expert in knee replacement surgery.

 

Risks

Total knee replacement, like any major surgical treatment, carries some medical hazards. Major problems are uncommon, although they can occur. Blood clots, bleeding, and anesthesia-related or medical hazards such as cardiac risks, stroke, and, in rare cases (big studies have determined the risk to be less than 1 in 400) mortality are all possible problems.

Infection (which may necessitate additional surgery), nerve injury, the possibility that the knee will become either too stiff or too unstable to enjoy, the possibility that pain will persist (or that new pains will arise), and the possibility that the joint replacement will not last the patient's lifetime or will necessitate additional surgery are all risks associated with knee replacement.

Despite the lengthy and daunting list of risks, the general frequency of significant issues following total knee replacement is minimal, often less than 5%. The total risk of surgery is obviously reliant on both the severity of the knee condition and the patient's general medical state.

 

Physical therapy

Patients undergoing total knee replacement will participate in either home physical therapy or outpatient physical therapy at a site near to home after being discharged from the hospital (or inpatient rehabilitation)

Physical therapy can take anywhere from six to eight weeks, depending on the patient's age, fitness, and level of drive. This method typically requires two to three therapy sessions each week.

Physical treatment begins with range-of-motion exercises and gait training (supervised walking with an assistive device like a cane crutches or walker). Strengthening activities and the transition to regular walking without support aids are encouraged when such things become second nature.

Between supervised physical therapy appointments, all patients are given a set of home exercises to undertake, and the home exercises are a crucial component of the rehabilitation process. However, supervised therapy best performed in an outpatient physical therapy studio is tremendously beneficial, and patients who are able to attend outpatient therapy are urged to do so. 

 

Will I need any treatments after knee replacement?

Your healthcare team will prescribe medications to help you manage pain after surgery, such as:

• Acetaminophen.
• Opioids. (Provided for limited time following surgery.)
• NSAIDs.

To prevent blood clots and control swelling, your healthcare team might also recommend:

• Blood thinners, such as aspirin or injectable Enoxaparin based on individual risk of blood clot formation.
• Compression devices, usually used while hospitalized. These are mechanical devises which provide intermittent compression.
• Special support hose.

To maintain blood flow at home, your team will advise you to move your foot and ankle often. They will also demonstrate unique exercises to help strengthen and restore mobility to your knee. Exercises are critical to the success of your knee replacement surgery. Physical treatment will begin in the home.

 

What the alternatives to knee replacement?

After alternative therapies for knee discomfort have failed, a healthcare physician may propose knee replacement surgery. Among the earlier alternatives are:

• Exercise or physical therapy to strengthen the muscles around the joint which will provide stability.
• Knee arthroscopy for mechanical issues.
• Medications such as NSAIDs and cortisone shots.
• Walking aids or supports (for example, a cane or walker) and bracing.

 

Unicompartmental partial knee replacement

If arthritis affects only one side of your knee – usually the inner side – it may be possible to have a partial (unicompartmental) knee replacement.

There are three compartments of the knee:

• The inner (medial), 
• The outer (lateral) and 
• The kneecap (patellofemoral).

If your arthritis affects only one side of your knee, generally the inner side, a half-knee replacement may be an option (sometimes called unicompartmental or partial replacement). Because there is less interference with the knee than with a total knee replacement, this typically results in a faster recovery and improved function.

Partial knee replacements can be performed with a smaller incision (cut) than whole knee replacements, thanks to procedures known as reduced invasive or minimally invasive surgery. A smaller incision may shorten recuperation time even more.

Because you must have strong, healthy ligaments within your knee, partial knee replacement is not for everyone. This is sometimes not discovered until the day of operation.

According to research, persons who have partial knee replacements are more likely to have the knee updated than people who get whole knee replacements - around one out of every ten people requires further surgery after 10 years. Even though there is less interference with the knee, the procedure is generally more difficult than total knee replacement. As a result, your surgeon may want to offer you a more predictable complete knee replacement.

At any age, a partial knee replacement might be considered. It allows younger people to keep more bone, which is beneficial if revision surgery is required later on. For the elderly, partial knee replacement is a less demanding procedure with less discomfort and danger of bleeding. However, the result of the procedure is determined by the type of arthritis rather than your age.

 

Conclusion 

The knee is a hinge joint that allows mobility where the thigh joins the lower leg. Total knee replacement is a surgical technique that replaces the damaged knee joint with new material. It gives consistent results for individuals with end-stage degenerative hip osteoarthritis. It can specifically relieve pain, restore function, and contribute to an enhanced quality of life.