Foot and Ankle
- Foot and Ankle Anatomy
Anatomy of the Foot and Ankle
What is the Normal Anatomy of the Foot and Ankle?
The foot and ankle form complex joints that are involved in movement and providing stability and balance to the body. The foot and 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: the 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.
- The posterior malleolus, also formed by the tibia, is found at the back of the ankle.
- The 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 that 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 bones called 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 helps in upward and downward movements 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 and ankle provide stability and support the weight of your body, helping you to walk or run, and adapt to uneven grounds.
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.
The joint surface of all the bones of the ankle and foot are lined by a thin, tough, flexible, and slippery surface called the 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.
Ligaments are tough rope-like tissue that connect bones to other bones, and hold 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 lower side 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 that help in movement. The main muscles include:
- Anterior tibial muscle, which allows up and down movement of the foot
- Posterior tibial muscle, which supports the arch
- Peroneal tibial muscle, which controls movement on the outside of the ankle
- Extensors, which enable the ankle to raise the toes just before stepping forward
- Flexors, which stabilize the toes against the floor
- Smaller muscles that help the toes to 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. They contain special cells called synovial cells that secrete a lubricating fluid.
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.
Ankle dislocation is a condition that occurs when the bones of the lower leg called the fibula and tibia get separated from the talus or ankle bone. This can cause serious damage to the nerves and ligaments surrounding the ankle, leading to a decline in strength and overall health of the leg.
Foot and Ankle Trauma
The foot and ankle work together to provide balance, stability, movement, and propulsion to the human body. Its complex anatomy consists of 26 bones, 33 joints, muscles, tendons, ligaments, blood vessels, nerves, and soft tissues.
The joints of the ankle are held in place and stabilized by strong bands of tissue called ligaments. Ankle instability is a chronic condition characterized by a recurrent slipping of the outer side of the ankle. It usually results from repeated ankle sprains, which are injuries to the ligaments. Ankle instability is generally noticed when you move your ankle joint but can also occur while standing.
A sprain is the stretching or tearing of ligaments. Ligaments 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 jump or run on a surface that is irregular.
Charcot Foot Deformity
Charcot foot deformity, also known as Charcot arthropathy, is a condition characterized by weakness and inflammation of the bones, joints, and tissues of the foot. If not treated appropriately, it can lead to joint collapse and loss of mobility.
A corn is a circular area of thickened skin developed because of continuous friction or pressure. They usually develop on the soles of feet or on the top or sides of toes and appear as yellowish dead tissue surrounding an area of tenderness. Pain and discomfort may be present with walking, which can become more painful without treatment.
Flatfoot, also known as “fallen arches” or Pes planus, is a deformity in children’s feet where the arch that runs along the sole of the foot collapses to the ground or is not formed at all. Flatfoot is normal in the first few years of life as the arch of the foot usually develops between the age of 3 and 5 years.
Foot and Ankle Arthritis
Arthritis is the inflammation of joints as a result of degeneration of the smooth cartilage that lines the ends of bones in a joint. This degeneration of the cartilages leads to painful rubbing of the bones, swelling, and stiffness in the joints, resulting in restricted movements.
Ankle Ligament Reconstruction
A sprain is the stretching or tearing of a ligament. Ligaments connect adjacent bones in a joint and provide stability to the joint.
Minimally Invasive Bunion Surgery
Minimally invasive bunion surgery, also known as keyhole bunion surgery, is a procedure to treat a foot condition called a bunion or hallux valgus.
Ankle fusion, also known as ankle arthrodesis, is a surgical procedure commonly employed for the treatment of ankle arthritis in which the joint cartilage is severely damaged.
Plantar Fascia Release
Plantar fascia release is a surgical procedure to treat moderate to severe plantar fasciitis, in which your surgeon releases or removes the diseased section of the plantar fascia tissue to relieve pain and inflammation in the foot.
Treatment of Foot and Ankle Sports Injuries
Injuries during sports are common. They can result from accidents, inadequate training, improper use of protective devices, or insufficient stretching or warm-up exercises.
Post-Traumatic Reconstruction of the Foot and Ankle
Post-traumatic reconstruction of the foot and ankle is a surgical procedure performed for the correction of foot and ankle deformities as a result of traumatic injury and to restore lost function.
Open Reduction and Internal Fixation of the Ankle
Open reduction and internal fixation (ORIF) of the ankle is a surgical procedure performed to repair serious fractures (broken bones) of the ankle. It is performed on one or more of the three bones that form the ankle joint.