Total Knee Replacement
Total knee replacement, also called total knee arthroplasty, is a surgical procedure in which the worn out or damaged surfaces of the knee joint are removed and resurfaced with meatl and plastic components.
What is Arthritis?
The knee is made up of the femur (thighbone), the tibia (shinbone), and patella (kneecap). The surfaces of all these bones are covered in articular cartilage which serves as a cushion and helps absorb shock during motion. The menisci - the soft cartilage between the femur and tibia – also serve as further ‘protection’ for the joint surfaces. With time (age) or following significant knee injuries this articular cartilage can thin and ultimately expose the bone surfaces. This process is “arthritis” and it can lead to extreme pain and difficulty in performing daily activities In addition, the bones become thicker around the edges of the joint and may form bony “spurs”. These factors can cause pain and restricted range of motion in the joint. Osteoarthritis is a type of arthritis. The knee joint is composed of 3 ‘compartments’ – the medial (inner), the lateral (outer) and the patella-femoral (knee cap) – and if at least 2 of these are involved with significant osteoarthritis a total knee replacement is the recommended operation.
Causes of Osteoarthritis
The exact cause of osteoarthritis is still being established but there are several factors that are commonly associated with the onset of arthritis:
- Injury or trauma (fractures) to the joint
- Fractures at the knee joint
- Increased body weight
- Repetitive overuse
- Joint infection
- Inflammation of the joint
- Connective tissue disorders
Diagnosis of Osteoarthritis
Your doctor will diagnose osteoarthritis based on the medical history, physical examination, and X-rays.
X-rays typically show a narrowing of the joint space in the arthritic knee.
What is Total Knee Replacement?
Total knee replacement, also called total knee arthroplasty, is a surgical procedure in which the worn out or damaged surfaces of the knee joint are removed and replaced with artificial parts.
Indications for Total Knee Replacement
Total knee replacement surgery is commonly indicated for severe osteoarthritis of the knee which doesn’t respond to non-operative treatments such as weight loss or strengthening.
Osteoarthritis is the most common form of knee arthritis.
Your doctor may advise total knee replacement if you have:
- Severe knee pain which limits your daily activities (such as walking, getting up from a chair or climbing stairs).
- Moderate to severe pain that occurs during rest or awakens you at night.
- Chronic knee inflammation and swelling that is not relieved with rest or medications
- Failure to obtain pain relief from medications, injections, physical therapy, or other conservative treatments.
Total Knee Replacement Procedure
The goal of total knee replacement surgery is to relieve pain and restore the alignment and function of your knee.
The surgery is performed under spinal or general anaesthesia. Your surgeon will make an incision in the skin over the affected knee to expose the knee joint. Then, the damaged portions of the femur bone are cut at appropriate angles using specialised jigs. The femoral component is attached to the end of the femur with bone cement.
The surgeon then cuts away the damaged area of the tibia (shinbone) and the cartilage. This removes the deformed part of the bone and any bony growths, as well as creates a smooth surface on which the implants can be attached. Next, the tibial component is secured to the end of the bone with bone cement.
Your surgeon will then place an appropriate sized plastic piece between the implants to provide a smooth gliding surface for movement. This plastic insert will support the body’s weight and allow the femur to move over the tibia, like the original articular cartilage.
The femur and the tibia with the new components are then put together to form the new knee joint.
To make sure the patella (kneecap) glides smoothly over the new artificial knee, its rear surface is also prepared to receive a plastic component.
With all the new components in place, the knee joint is tested through its range of motion. The entire joint is then irrigated and cleaned with a sterile solution. The incision is carefully closed and a sterile dressing is placed over the incision.
Postoperative Care Following Total Knee Replacement
Rehabilitation begins immediately following the surgery. A physical therapist will teach you specific exercises to strengthen your leg and restore knee movement and you will be able to walk with crutches or a walker. Your physical therapist will provide you with a home exercise program to strengthen thigh and calf muscles.
Risks and Complications of Total Knee Replacement
As with any major surgery, there are possible risks and complications associated with total knee replacement surgery which include:
- Knee stiffness
- Blood clots (deep vein thrombosis)
- Nerve and blood vessel damage
- Ligament injuries
- Plastic liner wears out
- Loosening of the implant
Click here for Total Knee Replacement - Procedure Information Booklet
If you find it difficult to perform simple activities such as walking or climbing stairs because of your severe arthritic knee pain, then total knee replacement may be an option for you. It is a safe and effective procedure to relieve pain, correct leg deformity, and help you resume your normal activities of daily living.