Foot & Ankle
Foot & Ankle Anatomy
The Foot & Ankle form a complex joint involved in movement and providing stability and balance to the body. The Foot & Ankle consist of 26 bones, 33 joints, and many muscles, tendons and ligaments.
Bones of the Ankle
The ankle joint connects the leg with the foot and is composed of three bones: tibia, fibula and talus. The tibia or shinbone and fibula or calf bone are bones of the lower leg which articulate with the talus or ankle bone, enabling up and down movement of the foot.
Three bony bumps present on the ends of the tibia and fibula form parts of the ankle joint:
- The medial malleolus, formed by the tibia, is found on the inside of the ankle.
- Posterior malleolus, also formed by the tibia, is found at the back of the ankle.
- Lateral malleolus, formed by the fibula, is found on the outer aspect of the ankle.
Bones of the Feet
The foot acts as a single functional unit, but can be divided into three parts: the hindfoot, midfoot and forefoot.
The hindfoot forms the ankle and heel and is made up of the talus bone and calcaneus or heel bone. The heel bone is the largest bone in the foot.
The midfoot connects the hindfoot to the forefoot, and consists of one navicular bone, one cuboid bone, and three cuneiform bones. The navicular bone is found in front of the heel bone, and the cuneiform and cuboid bones are arranged in front of the navicular bone.
These bones are connected to five metatarsal bones of the forefoot, which form the arch of the foot for shock absorption while walking or running. The forefoot is also made up of the toes or digits, formed by phalanges, three in each toe, except the big toe, which has only two phalanges. The big toe has two additional tiny round sesamoid bones in the ball of the foot, which help in upward and downward movement of the toe.
Ankle and Foot Joints
There are 33 joints in the ankle and foot. They include:
- Hinge joints in the ankle, which allow flexion (bending) and extension
- Gliding joints found in the hindfoot, which allow gliding movements
- Condyloid joints found in the forefoot and toes, which allow the flexion (bending) and extension, adduction and abduction (sideward movement).
The joints of the Foot & Ankle provide stability and support the weight of the body, helping you to walk or run, and to adapt to uneven ground.
The joint surface of all bones of the ankle and foot are lined by a thin, tough, flexible, and slippery surface called articular cartilage, which acts as a shock absorber and cushion to reduce friction between the bones. The cartilage is lubricated by synovial fluid, which further enables smooth movement of the bones.
Soft Tissues of the Ankle and Foot
Our feet and ankle bones are held in place and supported by various soft tissues such as cartilage, ligaments, muscles, tendons and bursae.
Cartilage is the flexible, shiny, smooth tissue on the ends of bones that meet to form a joint. Cartilage provides cushioning between the bones allowing smooth movement.
Ligaments are tough rope-like tissue that connect bones to other bones, and holds them in place providing stability to the joints. The plantar fascia is the largest ligament in the foot, originating from the heel bone to the forefoot, it extends along the bottom surface of the foot and is involved in maintaining the arch of the foot. The plantar fascia ligament stretches and contracts to provide balance and strength to the foot. Lateral ligaments on the outside of the foot and medial ligaments on the inside of the foot provide stability and allow up and down movement of the foot.
The foot is made up of 20 muscles, which help in movement. The main muscles include:
- Anterior tibial muscle: allows up and down movement of the foot
- Posterior tibial muscle: supports the arch
- Peroneal tibial muscle: controls movement on the outside of the ankle
- Extensors: enable the ankle to raise the toes just before stepping forward
- Flexors: stabilize the toes against the floor
- Smaller muscles are also present to help the toes lift and curl.
Tendons are soft tissues that connect muscles to bones. The largest and strongest tendon in the foot is the Achilles tendon, present at the back of the lower leg around the heel bone. Other tendons include peroneal and anterior and posterior tibialis.
Bursae are small fluid-filled sacs that decrease friction between tendons and bone or skin. Bursae contain special cells called synovial cells that secrete a lubricating fluid.
A sprain is the stretching or tearing of ligaments, which connect adjacent bones and provide stability to a joint. An ankle sprain is a common injury that occurs when you suddenly fall or twist the ankle joint or when you land your foot in an awkward position after a jump. Most commonly it occurs when you participate in sports or when you jump or run on a surface that is irregular.
Achilles Tendon Rupture
The Achilles tendon is a strong, fibrous cord present behind the ankle that connects the calf muscles to the heel bone. It is used when you walk, run and jump. The Achilles tendon ruptures most often in athletes participating in sports that involve running, pivoting and jumping. Recreational sports that may cause Achilles rupture include tennis, football, basketball and gymnastics.
Osteochondral Injuries of the Ankle
The ankle joint is an articulation of the end of the tibia and fibula (shinbones) with the talus (heel bone). Osteochondral injuries, also called osteochondritis dissecans, are injuries to the talus bone, characterized by damage to the bone as well as the cartilage covering it. Sometimes, the lower end of the tibia or shinbone may also be affected.
Ankle Ligament Injury
An ankle ligament injury, also known as an ankle sprain, can be caused by a sudden twisting movement of the foot during any athletic event or during daily activities. It is one of the most common orthopedic injuries and can also be caused by walking down a slope or over any uneven surface. The injury can range from mild to severe, depending on the condition of the injured ligament and the number of ligaments involved.
Foot & Ankle Arthritis
Arthritis is inflammation resulting from the degeneration of cartilage in the joint causing joint pain, swelling, and stiffness resulting in restricted movements. Arthritis of the Foot & Ankle joint can occur due to fractures, dislocation, inflammatory disease, or congenital deformity.
The hind foot is separated from the midfoot by the medio tarsal joint and the midfoot is separated from the forefoot by the Lisfranc joint. Muscles, tendons and ligaments support the bones and joints of the feet enabling them to withstand the entire weight of the body while walking, running and jumping.
A bunion is a bony protuberance that appears on the outer surface of the big toe when it angles toward the adjacent toe. It is an extra bone and a fluid-filled sac that grows at the base of the big toe.
Bunions are common in women and tend to run in families (heredity).
Plantar fasciitis refers to inflammation of the plantar fascia, a thick band of tissue that is present at the bottom of the foot. It runs from the heel bone to the toe and forms the arch of your foot. Plantar fasciitis is one of the most common causes of heel pain. It is most often seen in middle-aged men and women, but may also occur in those who are constantly on their feet.
Foot & Ankle Arthroscopic Surgery
Foot and ankle arthroscopy is a minimally invasive surgical procedure in which an arthroscope, a small, soft, flexible tube with a light and video camera at the end, is inserted into the foot or ankle joint to evaluate and treat a variety of conditions.
Foot & Ankle Reconstructive Surgery
Foot and ankle reconstruction is a surgery performed to correct the structures of the foot and ankle, and restore the natural functionality of the foot that has been lost due to injury or illness. Ideally, any foot surgery for reconstruction is done to improve the appearance and function of the foot so that patients can maintain their quality of life.
Achilles Tendon Repair
Tendons are the soft tissues connecting muscle to bone. The Achilles tendon is the longest tendon in the body and is present behind the ankle, joining the calf muscles with the heel bone. Contraction of the calf muscles tightens the Achilles tendon and pulls the heel, enabling the foot and toe movements necessary for walking, running and jumping.