Knee joint is involved in almost every movement. Simple activities such as walking, bending, and turning require the use of knee and hip joints. The knee is the body’s largest joint and supports bod’s weight. It’s the place where three large bones meet: the tibia (shin bone), the femur (thigh bone) and the patella also known as the knee cap. Many strong ligaments surround the joint capsule of the knee to reinforce its structure and hold its bones in the proper alignment.
As knees bear our body’s weight, they are vulnerable to injury and osteoarthritis.
The base of the knee is formed by the tibia. This bone, also called the “shinbone,” is the large bone of the lower leg. The smaller bone of the lower leg, called the “fibula,” connects to the tibia just below the knee. It is not part of the joint. Above this is the femur, which is also known as the “thighbone.” This is the longest, largest and heaviest bone of the body. The patella, commonly called the “kneecap,” covers and protects the front of the knee joint.
Within the knee, the surfaces of the bones are covered with a layer smooth, soft material called articular cartilage. This smooth tissue acts as a lubricant to reduce friction and protects joint from the wear and tear. Healthy cartilage allows bones to glide smoothly as the knee flexes and extends.
Between the tibia and femur are two thick pads called “menisci.” Each one individually is called a “meniscus.” These are made of cartilage. They act as cushions for the two rounded protrusions on the end of the femur, which are called the “condyles.”
The tibia and the femur are connected to each other by a pair of strong bands of tissue called “cruciate ligaments.” The anterior cruciate ligament is commonly called the “ACL.” The posterior cruciate ligament is commonly called the “PCL.” These ligaments cross each other like an X in the center of the knee. The ACL keeps the tibia from slipping forward, and the PCL keeps it from slipping backward. These ligaments also limit the knee’s rotation.
Another set of ligaments, called the “collateral ligaments,” are found on the sides of the joint. They minimize side-to-side movement and help stabilize the knee.
The patella is secured in place at the front of the knee by the quadriceps tendon and the patellar ligament. These connect to the upper and lower portion of the patella. They allow the patella to move as the knee flexes and extends.