One of the most strained and biggest joints of the body is the knee. It is the most crucial joint for movement as well as most susceptible to injuries too. The knee is also one of the most complicated anatomies in the human body.
Knee anatomy’s facts
- The knee is responsible for joining the thigh bone, shin bone, fibula located on the outer side of the shin, and kneecap as well.
- The knee contains a fluid-filled capsule known as a synovial joint.
- A knee injury mostly incurs due to sports and recreational tasks.
- Instantaneous medical attention is needed in case of a direct hit on the knee, considered to be a grave injury
Anatomy of the knee
A hinge joint, the knee is accountable for wearing the weight and movement of the body. It embodies the bones, meniscus, ligaments, and tendons.
The knee is helpful in carrying out many functions:
- It supports the body to hold an upright position.
- helps to get down and elevate the body
- Helps in maintaining stability.
- Functions as a shock absorber.
- Helps in revolving the leg
- More efficient walking is possible
- Makes the body move forward
Bones
The knee comprises the femur(thigh bone), tibia(shin bone), and patella(knee cap). The knee joint is responsible for having these bones intact.
The small, triangle-shaped bone at the front of the knee is known as the patella. It is located in the quadriceps muscle. As it handles a lot of force, it is banded with a sturdy layer of cartilage in the body.
Cartilage
The cartilage is of two types
Meniscus: are the arc-shaped discs functioning as a cushion, or “shock absorber”. They help the bones of the knee to move across their range of motion avoiding rubbing against each other. The meniscus also has nerves assisting to improve balance and stability and ensuring that the weight is distributed appropriately between the femur and tibia.
The menisci are of two types
- medial – the medial is on the inner side of the knee.
- lateral – is on the outer side of the knee
The medial is the largest of the two
Articular cartilage: it is a fine, smooth layer of cartilage located on the femur, the upper part of the tibia, and at the rear of the patella. It helps bones move smoothly over one another acting as shock absorber.
Ligaments
Ligaments act like strong ropes helping to connect bones to other bones, avoiding too many movements thus promoting stability. They are strong and muscular tissue. The knee consists of four of them—-
- ACL (anterior cruciate ligament) – prevents the femur from sliding backward on the tibia, and the tibia from sliding forward on the femur.
- PCL (posterior cruciate ligament) – prevents the femur from sliding forward on the tibia, or the tibia from sliding backward on the femur.
- MCL (medial collateral ligament) – prevents side to side movement of the femur.
- LCL (lateral collateral ligament) – prevents side to side movement of the femur.
Tendons
They give stability to the joints being a tough strand of pulpy tissues. Being alike to ligaments, they link bone to muscle unlike ligaments linking bone to bone. The patellar tendon is the biggest tendon in the knee covering the kneecap, the thigh, and attaching to the quadriceps.
Muscles
However, not technically being part of the knee joint, the hamstrings and quadriceps are the muscles responsible for strengthening the leg and in the flexibility of the knee.
The quadriceps as the name suggests are four muscles for straightening the knee. The hamstrings are responsible for bending the knee made up of three muscles at the back of the thigh.
The gluteal muscles – are also important in positioning the knee. They comprise of the gluteus medius and minimus.
Joint capsule
The knee joint is encircled by a bag of membranes called joint capsules. Synovial fluid within these bags lubricates and nourishes the joint.
Bursa
They are small fluid-filled sacs within the knee joint. Their role is to lessen the friction between the tissues of the knee and avoid swelling thereof. There are approximately 14 of them.