Knee Replacement Surgery
Knee Replacement Surgery
Knee replacement is also called knee arthroplasty or total knee replacement. It is a surgical procedure to replace a knee damaged by arthritis. Metal and plastic parts are commonly used to cap the ends of the femoral and tibial bones that form the knee joint, along with the kneecap called the Patella. This surgery should only be considered for someone who has severe arthritis or a severe knee injury and is a good surgical candidate with low risk.
Many types of arthritis can affect the knee joint. Osteoarthritis is a degenerative joint disease that affects most middle-aged and older adults and can cause the breakdown of joint cartilage and surrounding bones of the knee joint. Rheumatoid arthritis causes inflammation of the synovial membrane(fluid lining of the joint) and then results in excessive synovial fluid, which leads to inflammation, pain, and stiffness. On the other hand, arthritis secondary to trauma is due to an injury that may cause damage to the cartilage of the knee joint.
The goal of knee replacement surgery is to replace all the parts of the knee joint that are damaged in an attempt to relieve knee pain that cannot be controlled by other treatments.
Anatomy of the knee
Joints are the space in the body where two or more bones meet. Most joints are mobile, which allows the bones to move. The knee is two long leg bones held together by muscles, ligaments, and tendons in which each bone end is covered with a layer of cartilage that absorbs shock protecting the knee.
There are two groups of muscles involved in the knee, which include the quadriceps muscles (front of the thighs), which straighten the legs, and the hamstring muscles (back of the thighs), which bend the leg at the knee joint.
Tendons are strong cords of connective tissue that connect muscles to bones. Ligaments are elastic band-like tissue that connects bone to bone. Some ligaments of the knee can provide stability and protection of the joints, while other ligaments can limit forward and backward movement of the tibia such as the shin bone.
Components of the knee include:
- Tibia: This is the shin bone is the largest bone of the lower leg.
- Femur: This is the big thighbone or upper leg bone.
- Patella: This is the kneecap.
- Cartilage: A type of soft tissue tissue that covers the surface of a bone at a joint. It helps reduce the friction of movement within a joint.
- Synovial membrane: A mucus-like tissue that lines the joint and seals it into a joint capsule. The synovial membrane secretes synovial fluid (which is a clear, sticky fluid) around the joint to lubricate it.
- Ligament: Is a tough, elastic connective tissue that surrounds the joint giving it support and limiting the joint’s movement.
- Tendon: Is a type of tough connective tissue that connects muscles to bones and which helps to control movement of the joint.
- Meniscus: Is a soft curved part of cartilage in the knees and other joints that acts as a shock absorber, and which increases the contact area, and deepens the knee joint.