Total knee replacement is a surgical method that offers a solution to your chronic knee pain that affects your daily life due to advanced joint wear and cartilage damage. This surgery involves replacing damaged knee joint surfaces with metal and plastic prostheses. It is specifically applied to increase your mobility and improve your quality of life. In this article, we will examine in detail what total knee replacement surgery is, who it is for, in which situations it is performed, the surgical process, and the subsequent recovery stages.
What Is Total Knee Replacement?
The process of covering worn knee joint surfaces with metal and polyethylene materials is called total knee replacement. First performed in 1968, this method now yields highly successful results thanks to advancements in surgical techniques and material technology. In more than 90% of patients, a significant reduction in knee pain and a major improvement in daily activities are achieved.
In this surgery, the joint surfaces are completely cleaned and reconstructed with artificial joint parts. The worn cartilage tissue in the areas where the femur, tibia, and patella bones come into contact is removed along with a thin layer of bone. Subsequently, the prosthetic parts are placed on the bone surfaces, and a new joint structure that allows for pain-free movement is created.
Structure and Components of the Prosthesis
A total knee prosthesis basically consists of four main parts:
Femoral component: The part that covers the lower part of the thigh bone. It is usually made of a cobalt-chromium-molybdenum alloy. This metal is highly resistant to scratching.
Tibial component: The lower part placed on the upper part of the shinbone. It is produced from titanium or a chromium-cobalt alloy. It holds the plastic spacer.
Plastic liner: The polyethylene spacer that fills the gap between the two metal parts. It acts like new knee cartilage and reduces friction in the joint.
Patellar component: The part made of plastic placed on the back surface of the kneecap. Some surgeons do not use it routinely.
These materials do not cause allergic reactions in the body and rapidly adapt to other tissues in the knee joint. Prostheses are designed to fit knee anatomy and are produced in 2 mm increments to accommodate different joint sizes.
Prosthetic parts are fixed to the bone with a filler material called bone cement. In cementless prostheses, porous structures on the surface are placed tightly into the bone, and over time, the bone grows into the pores to ensure fixation.
Types of Prostheses
Total knee replacement is the most commonly applied type. All damaged surfaces of the knee joint are replaced. It is applied in cases where all three compartments of the joint are damaged or when severe deformities begin in the knee. It has a high success rate in completely eliminating pain.
Partial knee replacement (unicondylar prosthesis), on the other hand, is applied to only one part of the knee. It is preferred for osteoarthritis in the inner or outer part of the knee in patients with intact knee ligaments. A smaller incision is made, and the hospital stay is shorter. It cannot be applied in advanced osteoarthritis cases.
There are also ligament-sparing or ligament-sacrificing designs. The appropriate design is chosen based on the amount of deformity in the knee, the state of wear, and the limitation of movement. Prostheses that provide high range of motion and special designs that reduce wear are also available.
The lifespan of prostheses has extended up to 15-20 years with appropriate surgical techniques and modern designs. Some sources state that this period has increased to 25-30 years with developing technology. Prosthesis lifespan depends on three factors: the surgeon's experience, the quality of the prosthesis, and the patient's usage pattern.
Who Is Total Knee Replacement For?
When severe damage occurs in the knee joint and conservative methods such as medication, physical therapy, and injections do not yield results, total knee replacement surgery comes to the agenda. The decision for surgery is made not only based on X-ray findings but also by looking at how much the patient's daily life is affected. It is generally applied to patients over the age of 55, but it can also be performed at younger ages in certain medical conditions.
Advanced Stage Knee Osteoarthritis
The most common reason for total knee replacement is advanced osteoarthritis. The cartilage tissue in the joint wears down over time, and the bones begin to rub against each other. Aging, excess weight, past traumas, or family predisposition accelerate osteoarthritis.
Severe pain that increases with movement, morning stiffness, and difficulty climbing stairs are common in these patients. In early stages, medications and physical therapy provide relief. However, in advanced stages, the only solution is surgical intervention.
Some clear criteria indicate that it is time for surgery. Prosthetic surgery is considered in cases of inability to walk 100 meters, the need for daily painkillers, sleep disturbances due to night pain, difficulty in movement due to deformity in the knee, and the need for assistance in daily tasks. Complaints that persist even during rest and do not respond to painkillers are strong indicators for surgery.
Rheumatoid Arthritis
Rheumatoid arthritis, which occurs as a result of the immune system targeting its own joints, causes permanent damage to the knees. The knees are affected in 20-30% of people with this disease. Symmetrical pain in both knees, morning stiffness, and deformity in the joints are typical symptoms.
Anti-inflammatory drugs can be effective in the early stages. However, in advanced stages, total knee replacement is the most successful option. The age limit for surgery is more flexible in rheumatoid arthritis patients and can be applied even at younger ages depending on the patient's condition. Studies show that the prosthesis is extremely effective in relieving pain and improving knee mobility in this patient group, and successful long-term results are obtained in more than 80% of patients.
Post-Traumatic Joint Damage
Accidents, falls, or sports injuries can cause permanent damage to the knee. When bone fractures do not heal properly or ligament injuries disrupt the joint structure, deformity and constant pain develop. A prosthesis may also be required if previous surgical procedures fail.
In these post-traumatic conditions, conservative treatments are usually insufficient. Due to the structural impairment in the joint, a prosthesis is the most effective way to repair the damage.
Chronic Knee Pain and Limited Mobility
Chronic knee pain that seriously affects quality of life is an important indicator for a prosthesis. Difficulty sitting and standing, pain that interrupts night sleep, inability to walk long distances, and the constant need for a cane or walker point to this situation.
A decrease in pain-free walking distance to under 300 meters strengthens the decision for surgery. Patients who have to take painkillers every day are at risk of kidney and liver damage due to the medication. Therefore, a prosthesis is applied to prevent the need for painkillers and increase walking distance. Most patients can walk independently and return to an active life after surgery.
How Is Total Knee Replacement Surgery Performed?
The surgical process requires meticulous planning from the preparation stage onwards. The success of the surgery largely depends on the checks and preparations made before the operation. This process aims to ensure that your body is ready for the operation and that the risks of complications are minimized.
Preoperative Preparation
A series of medical evaluations are performed 30 days before the surgery. Systemic screenings such as blood tests, urinalysis, ECG, and chest X-rays are carried out. If you have chronic diseases such as diabetes or hypertension, they must be brought under control.
The risk of infection is the most carefully monitored issue before surgery. Tooth decay, abscesses, or infections must be treated. If you have a urinary tract infection, it is cured before the surgery. If you have fungus on your nails, dermatological treatment is performed. A hidden infection anywhere in your body poses a major risk for the prosthesis.
The medications you use are reviewed. Blood thinners must be stopped before surgery. Aspirin is stopped 10 days, Coumadin 5 days, and Plavix 7 days before. Vitamins and supplements are also stopped 10 days before. Insulin and diabetes medications are not taken on the day of surgery.
If you are overweight, it is recommended to lose weight. Excess weight puts stress on your joints and increases surgical risks. When you lose 4 kilos, the load on your knee decreases by approximately 18 kilos. You can also perform exercises to strengthen your leg muscles before surgery.
Nothing should be eaten or drunk for the last 8 hours before surgery. The surgical area is washed with an antibacterial solution. Lotions, deodorants, and perfumes are not used, makeup is not applied, and nail polish is removed. Prepare aids such as a walker, toilet seat riser, and bathroom grab bars at home in advance.
Surgical Process
Total knee replacement surgery takes an average of 1-2 hours. A 10-12 cm long incision is made on the front of the knee. In young patients without weight problems, the procedure can be performed with a smaller incision. Thus, less damage is done to muscles and tendons.
The kneecap is tilted to the side, and the joint is exposed. The menisci are removed, and calcifications are cleaned. Cuts are made on the upper ends of the femur and tibia bones with the help of a saw. The worn cartilage tissue is cut and removed along with a thin layer of bone.
Prosthetic parts of the appropriate size are placed on the prepared bone surfaces. First, trial prostheses are attached to check the ligament balance of the knee. The looseness or tightness of the joint is adjusted. Subsequently, the trial prostheses are removed, the joint is washed, and the original prostheses are fixed with bone cement.
A plastic joint surface is placed between the metal prosthetic parts. The back surface of the kneecap is prepared with a plastic component. Joint range of motion is tested. Bleeding control is performed, and the incision is closed with sutures.
Anesthesia Methods
The surgery is performed under spinal anesthesia administered from the lower back or general anesthesia. Spinal anesthesia is the preferred method. In regional anesthesia, the patient is awake, but the lower body is numbed.
Spinal anesthesia has advantages. The patient does not have pain at the end of the surgery. Thanks to catheters inserted into the back, pain control is provided in the early period. There are no lung problems, and patients do not feel pain for 5-6 hours.
In general anesthesia, the patient has severe pain at the end of the surgery. Pain begins when anesthesia ends. However, numbing from the back may not be suitable for some patients. The anesthesiologist decides on the most appropriate form of anesthesia according to the patient.
Pain pumps that deliver medication via epidural or intravenous routes are used for postoperative pain control.
Recovery Process After Total Knee Replacement
The recovery period begins the moment you leave the operating room and is as important as the surgery itself for a successful outcome. The more you adhere to the rehabilitation process, the faster your knee will regain functionality and the sooner you will return to a pain-free life.
Hospital Stay Duration
Today, the hospital stay for most routine cases is between 1-3 days. Some patients can go home on the same day under selected conditions. However, what matters is not the shortness of the duration, but safe discharge.
The first day after surgery usually passes with rest, fluid balance monitoring, and observation of vital signs. The physiotherapist helps you start light exercises on the first day after surgery or the day after. Many centers aim to get the patient up within the first 24 hours. This early movement prevents blood clotting and regulates circulation.
Certain criteria must be met before discharge. Your pain must be controllable with oral medications, you must be able to walk a short distance safely with a walker or crutches, and you must be able to meet your toilet needs. If there are stairs at home, the physiotherapist provides training for this.
Physical Therapy and Exercise Program
Physical therapy begins in the first 24-48 hours of surgery. Within the first 1-3 days, ankle pumping exercises, straight leg raise exercises, and ice applications are performed. At this stage, the CPM device moves your knee in a controlled manner to increase blood circulation and prevent stiffness in the joint.
Within 4-10 days after surgery, strengthening of the leg and hip muscles is ensured. Between 2-6 weeks after surgery, stair climbing and lunge exercises are performed. You need to have good quadriceps muscle strength to be able to climb stairs.
Between 7-12 weeks after surgery, return-to-function exercises such as squatting and walking are performed. Between 14-26 weeks after surgery, more active exercises such as swimming and cycling are started.
Physical therapy programs usually last between 8 to 10 weeks. However, some sources recommend at least 4 weeks, ideally 8 weeks, of physical therapy. Proper planning of the rehabilitation process significantly affects the success rate of the surgery.
Pain Management
Pain is felt most during the first day and night after surgery. However, with modern pain control techniques, this pain is now at a manageable level. With epidural or nerve block methods, pain is kept at a minimum level during the first 24-48 hours after surgery.
It is very natural to have pain, especially within the first three weeks, both during the healing of soft tissue and while gaining range of motion. There may be some pain within the first three months. Pain usually subsides to a very mild level after 3-4 days and disappears within days.
With good pain control, patient satisfaction increases, rehabilitation applications become easier, and the hospital stay is shortened. Well-controlled postoperative pain is directly related to early functional recovery and patient satisfaction.
Return to Daily Activities
You may have returned to most of your daily activities and your job 1 month after surgery. Generally, you can return to your daily activities within 3-6 months and go back to sports that do not cause heavy loads on the knee, such as walking, swimming, cycling, dancing, and yoga.
You are allowed to drive about six to eight weeks after surgery. Full recovery takes several months, but a 6-month controlled exercise and follow-up period is recommended for full functional gain. By the 12th week, you should have a full range of motion in your knee and feel minimal or no pain while participating in regular activities.
Frequently Asked Questions
After making the decision for surgery, patients want to get information about topics such as surgery duration, durability of the prosthesis, and the recovery process. In this section, we answer the most frequently asked questions.
How long does total knee replacement surgery take?
The surgery duration is usually completed between 1 and 2 hours. This time may vary depending on the surgeon's experience and the patient's condition. In some centers, the surgery may take 1.5 to 3 hours. When operating room preparation and anesthesia procedures are added, the total time can be 2-3 hours.
Keeping the surgery duration short reduces anesthesia time, accelerates postoperative recovery, and lowers the risk of complications. In surgeries planned by an experienced surgeon, the process proceeds more controllably.
What is the lifespan of the prosthesis?
The lifespan of modern prostheses is on average 15-20 years. With developing technology and high-quality materials, this period has extended to 20-25 years. Some sources state that the prosthesis lifespan has increased to 25-30 years.
Factors affecting prosthesis lifespan include the patient's weight, level of daily activity, correct placement of the prosthesis, and adherence to postoperative care. In overweight patients or people living a very active life, the prosthesis lifespan may decrease by up to 5 years. Maintaining weight control, doing regular exercises, and going to routine physician examinations extend the prosthesis lifespan.
When can I walk after surgery?
You will be helped to stand up within the first 24 hours after surgery. You can usually start walking 2-3 days after surgery. Some patients stand up with the help of a walker on the day of surgery or the next morning.
Walking with support begins within the first week. Gaining the ability to walk completely without assistive devices can take 4-6 weeks, depending on your recovery speed and adherence to physical therapy. Most patients gain the potential to walk as much as social life requires in 6-8 weeks.
What are the risks of total knee replacement?
As with any surgical procedure, there are certain risks in total knee replacement surgery. The risk of infection is at the forefront. The formation of blood clots in the leg veins and their reaching the lungs is a serious condition. However, the rate of this risk is less than 1 percent.
Other risks include loosening or wear of the prosthesis over time, temporary limitation of movement after surgery, and rarely, pain around the prosthesis and nerve or vascular damage. Thanks to current surgical techniques, sterile operating room conditions, and personalized surgical planning, these risks can be largely controlled.
How are postoperative check-ups performed?
Check-ups are usually performed several times in the first year after surgery. Afterwards, a check-up with an orthopedist once a year is recommended. During check-ups, X-rays are taken to evaluate the position of the prosthesis and whether there is any loosening or wear. Even if there are no complaints, regular check-ups are important for the early detection of potential problems.
In Summary
Total knee replacement is an effective solution you can turn to when your quality of life drops due to chronic knee pain and limited mobility. When medication treatments and physical therapy methods do not yield results, prosthetic surgery becomes the most reliable option for pain-free walking and independent living.
Undoubtedly, making the decision for surgery is an important step. However, with the right patient selection, an experienced surgeon, and adherence to postoperative physical therapy, the vast majority of patients achieve successful results. A few months after surgery, you can return to your daily activities, walk pain-free, and lead a more active life.
