Fibula

You have a thin bone in your leg.

It is called the fibula. It sits next to a bigger bone. It does not carry much weight.

This bone helps keep your ankle steady. It also gives muscles a place to hold on. Muscles pull on the bone to help you move.

The bone looks like a small pin. It is the thinnest of all long bones. It is a very important part of your leg.

The fibula is a bone in your lower leg.

It sits next to the tibia. The tibia is the larger bone in your leg. The fibula is the thinnest of all long bones. Its name comes from a Latin word for a clasp or a pin. This is because the bone looks like a small pin.

This bone does not carry much weight for your body. Instead, it helps keep your ankle joint steady. It also gives many muscles a place to attach.

Muscles pull on the bone to help you move. You can see these muscle spots from the front or the back.

Your fibula grows in a special way. It starts as bone in the middle of the shaft. It also starts at each end. When you are a baby, the ends are still soft cartilage. The bottom end turns to bone in your second year. The top end turns to bone around your fourth year. The ends finally join the main bone when you are older. The top part joins around age 25. The bottom part joins around age 20.

The fibula is a very important bone in your lower leg.

It sits on the outside of your leg, next to a larger bone called the tibia. While the tibia carries most of your weight, the fibula is much thinner. In fact, it is the most slender of all the long bones in the body. It does not carry much weight by itself. Instead, it helps make your ankle joint steady and strong. It also gives many muscles a place to hold on so you can move.

This bone works through many connections. A thin sheet called the interosseous membrane connects the fibula to the tibia. This membrane helps separate different muscles in your leg. The top of the bone connects to the tibia at a joint called the superior tibiofibular articulation. The bottom of the bone forms part of your ankle joint. This part is called the lateral malleolus. The bottom connection is a rough area where the two bones meet.

Learning about the fibula is like looking at a timeline of growth. The bone starts to harden from bone material during the eighth week of life in the womb. At birth, the ends of the bone are still soft cartilage. The lower end starts to turn into hard bone during the second year of life. The upper end begins this change around the fourth year. These two ends eventually join the main middle part of the bone. The bottom end joins around age 20, and the top joins around age 25.

Doctors find the fibula very useful for helping people. Because it does not carry much weight, parts of it can be moved to help others. In a special surgery, doctors might use the fibula to rebuild a jawbone. This is called a fibular free flap surgery. The bone has a good blood supply to help it stay healthy. A large vessel called the fibular artery supplies the middle part of the bone. Many small branches also provide blood to the outer layer of the bone.

Even the name of the bone tells a story. The word fibula comes from a Latin word that means a clasp or a brooch. People in the 1600s used this name because the bone looks like a small pin. This is a lot like how a modern safety pin works. In the animal kingdom, the fibula can look different. Some animals have a much smaller fibula. In a horse, the fibula even partially joins with the tibia.

The fibula, often called the calf bone, is a long bone located in the lower leg.

It sits on the lateral side of the tibia, which is the larger shin bone. While the tibia carries most of the body's weight, the fibula is much thinner. In fact, it is the most slender of all the long bones in the human body. The fibula is essential for providing stability to the ankle joint. It also serves as a critical attachment point for many muscles and ligaments.

The structure of the fibula involves several specific components and joints. At the top, the head of the fibula connects to the tibia at the superior tibiofibular articulation. This is an arthrodial joint, meaning it is a joint that allows for small movements. The bottom of the bone forms the lateral malleolus, which is the outer part of the ankle joint. A strong connection called the interosseous membrane links the fibula to the tibia. This membrane creates a syndesmosis joint, which is a type of joint held together by dense connective tissue. This connection helps separate different muscle groups within the leg.

The bone is divided into distinct anatomical parts: the head, the body, and the ends. The head is an irregular, quadrate shape located at the top. It has a pointed part called the styloid process, which is an upward projection. The body, or shaft, has four borders and four surfaces. These borders include the antero-lateral, antero-medial, postero-lateral, and postero-medial edges. The surfaces allow muscles like the soleus and the peronei to attach firmly. The lower end of the bone inclines slightly forward to help form the ankle structure.

Development of the fibula follows a specific timeline of ossification, which is the process of turning into bone. This process begins in the middle of the bone during the eighth week of fetal life. At birth, the ends of the bone are still made of soft cartilage. The lower end begins to ossify during the second year of life. The upper end follows later, starting around the fourth year. These parts eventually fuse with the main shaft. The lower end unites around age 20, while the upper end joins around age 25.

Understanding the blood supply is vital for medical procedures. The shaft receives blood through a large nutrient vessel from the fibular artery. This vessel supplies the middle third of the bone. The periosteum, which is the thin outer layer of the bone, also receives many small branches from the fibular artery. The proximal head and the epiphysis, or the end of the bone, are supplied by a branch of the anterior tibial artery. This rich blood supply is why surgeons often use the fibula in free tissue transfer. They can move parts of the bone to reconstruct other areas, such as the mandible, or jawbone.

Medical professionals study various types of fibula fractures. The most common fractures occur at the distal end, near the ankle. Doctors use the Danis–Weber classification to categorize these injuries. Type A fractures occur below the syndesmosis. Type B fractures happen at the level of the syndesmosis. Type C fractures occur above it. There is also a specific injury called a Maisonneuve fracture. This is a spiral fracture of the upper third of the bone. It is often linked to a tear in the interosseous membrane or the ankle ligaments.

The history of the word fibula is quite interesting. The term dates back to approximately 1670 and comes from the Latin word for a clasp or brooch. It was used in English to describe this specific leg bone around 1706. The name was chosen because the bone's shape resembles a small pin or clasp. This connection to a fastener is also seen in the Greek word peronē. In the animal kingdom, the fibula varies greatly. While humans use it for stability, some animals have a much smaller version. In horses, the fibula is even partially fused to the tibia.