Total Knee Replacement
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. Osteoarthritis is the most common form of knee arthritis in which the joint cartilage gradually wears away. It often affects older people.
In a normal joint, articular cartilage allows for smooth movement within the joint, whereas in an arthritic knee, the cartilage itself becomes thinner or completely absent. In addition, the bones become thicker around the edges of the joint and may form bony “spurs”. These factors can cause pain and restrict range of motion in the joint.
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.
- A bow- legged knee deformity
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 anesthesia. 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 specialized jigs. The femoral component is attached to the end of the femur with or without bone cement.
The surgeon then cuts or shaves 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 or screws.
Your surgeon will place a plastic piece called an articular surface 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 meniscus 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; drains are inserted 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. Knee immobilizers are used to stabilize the knee. You will be able to walk with crutches or a walker. A continuous passive motion (CPM) machine can be used to move the knee joint. Continuous passive motion is a device attached to the treated leg which constantly moves the joint through a controlled range of motion, while the patient relaxes. Your physical therapist will also 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, possible risks and complications associated with total knee replacement surgery include:
- Knee stiffness
- Blood clots (deep vein thrombosis)
- Nerve and blood vessel damage
- Ligament injuries
- Patella (kneecap) dislocation
- Plastic liner wearing out
- Loosening of the implant
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.
Computer Guided Total Knee Replacement
Computer-navigation provides your surgeon with real time 3-D images of your mapped knee and the surgical instruments during surgery. The data for the images is provided by the infrared sensors fixed to the bones of the knee and the surgical instruments. Their position is tracked by an infrared camera placed above the surgical table connected to the computer. The computer than generates the real-time images with the help of the appropriate software to guide the surgeon to precisely resurface and cut the bones of the knee and fix the implant precisely and accurately according to the pre-operative surgical plan.
Thus, the surgery is done by the surgeon only. Computer navigation is just a tool to guide the surgeon and improve the outcome of the surgery. It cannot replace the skills of an experienced surgeon.
By using the Orthalign computer navigation it allows us to obtain patient specific measurements and to insure proper size, alignment and fitment to match every individual knee.