The knee joints are large and complex. They need to allow standing, walking, and sitting smoothly and without pain. There are many parts in the knee structure, which, in turn, may cause many problems.

Your knee joint connects your thigh bone (femur) to the shin (tibia). It connects with smaller bone, the fibula. Those and the kneecap from the bony structure of your knee.
In addition to bones, soft tissues hold your joint together. Tendons connect the joint to leg muscles that allow you to move the knee. Ligaments join the bones of the together and stabilize the structure.
The following ligaments are essential structures to keep the bones of the knee in place and stable.

• The anterior (front) cruciate ligament stops the femur from sliding back onto the tibia and the tibia from going forward onto the femur.
• The posterior (back) cruciate ligament provides the opposite support. It keeps the femur from moving forward on the tibia and the tibia from sliding back on the femur.
• The medial (middle) and lateral (side) collateral ligaments stop the femur from moving sideways.

The knee has two pieces of cartilage that look like the letter C. They are called the medial and lateral menisci. A meniscus is a kind of shock absorber situated between the tibia and the femur.

Many fluid-filled sacs called bursae are situated in and around the knee to allow smooth movement.

There are common knee problems which can happen as a result from injuries, aging, and arthritis. Today, knee replacement surgeries are improving, even using robotic precision placements that enable the replacement to last longer.