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.
Ankle Sprain
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.
Ankle Fractures
Ankle injuries are very common in athletes and individuals performing physical work; often resulting in severe pain and impaired mobility. Pain after ankle injuries can either be from a torn ligament (ankle sprain)
Tarsal Tunnel Syndrome
The tarsal tunnel is a narrow passageway that lies on the inside of your ankle and runs into the foot. It encloses arteries, veins, tendons and nerves that supply the foot.
Ankle Instability
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.
Plantar Fasciitis
Plantar fasciitis refers to the 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 toes and forms the arch of your foot.
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.
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.
Achilles Tendinitis
The Achilles tendon is a tough band of fibrous tissue that runs down the back of your lower leg and connects your calf muscle to your heel bone. The tendon is used when you walk, climb, jump, run and stand on your tip toes.
Foot and Ankle Trauma
Foot and ankle trauma refers to injuries that most commonly occur during sports, exercise or any other physical activity. Trauma may be a result of accidents, poor training practices or use of improper gear.
Midfoot Arthritis
Midfoot arthritis is pain and inflammation of the midfoot. It occurs due to damage of cartilage or tissues around the joints. The damage may occur due to injury, aging or autoimmunity.
Osteochondral Injuries of the Ankle
The ankle joint is formed by the 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.
Lisfranc (Midfoot) Fracture
The Lisfranc joint or tarsometatarsal joint refers to the region in the middle of the foot. It is a junction between the tarsal bones (bones in the foot arch) and metatarsal bones (five long bones in the foot).
Foot Fracture
Trauma and repeated stress can cause fractures in the foot. Extreme force is required to fracture the bones in the hindfoot. The most common type of foot fracture is a stress fracture that occurs when repeated activities produce small cracks in the bones.
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. When stretched beyond its limit, the ligament may partially or completely tear.
Achilles Tendon Bursitis
Achilles tendon bursitis or retrocalcaneal bursitis is a condition that commonly occurs in athletes. It is a painful condition caused by the swelling of the bursa, a fluid-filled sac that is located at the back of the heel under the Achilles tendon..
Bunions
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.
Sesamoiditis
Sesamoids are two small, pea-shaped bones located in the ball beneath the big toe joint at the bottom of the foot. Sesamoid bones are connected to muscles and other bones by tendons that envelop these bones. Sesamoids help the big toe move normally and absorb the weight placed on the ball.
Fifth Metatarsal Fractures
The metatarsal bones are the long bones in your feet. There are five metatarsal bones in each foot. The fifth metatarsal is the long bone that is located on the outside of the foot and connects to the small toe.
Stress Fractures of Foot and Ankle
A stress fracture is described as a small crack in the bone which occurs from an overuse injury of a bone. It commonly develops in the weight-bearing bones of the lower leg and foot.
Ankle Arthroscopy
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 ankle joint to evaluate and treat a variety of conditions.
Minimally Invasive Foot Surgery
Minimally invasive foot surgery (MIFS) uses the latest advanced technology to treat foot and ankle pain caused by a variety of conditions. Special surgical instruments, devices, and advanced imaging techniques are used to visualize and perform the surgery through small incisions.
Flatfoot Reconstruction
Foot reconstruction is a surgery performed to correct the structures of the foot and restore the natural functionality of the foot that has been lost due to injury or illness.
Ankle Instability Surgery
Ankle instability surgery is performed to treat an unstable ankle and involves the repair or replacement of a torn or stretched ligament.
Foot Reconstruction
Foot reconstruction is a surgery performed to correct the structures of the foot and restore the natural functionality of the foot that has been lost due to injury or illness.
Achilles Tendon Repair
The Achilles tendon is often injured during sports activities, resulting in an inflammatory condition called tendonitis, which is characterized by swelling and pain.
Ankle Arthrodesis
Ankle arthrodesis is the surgical fusion of bones that form the ankle joint. The ankle joint is formed by the tibia, talus, and the fibula bones.
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.
Midfoot Fusion
Midfoot fusion is a surgical procedure most commonly employed for the treatment of midfoot arthritis.
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.
Cavovarus Foot Correction
To support the entire body’s weight on your two feet, the inner middle portion of each foot (midfoot) is raised off the ground to form an arch. A cavovarus foot deformity is characterized by a higher-than-normal arch of the inner midfoot.
Bunionette Surgery
Bunionette surgery is an outpatient surgical procedure that involves shaving off part of the bony lump and realigning the displaced fifth metatarsal to restore normal foot function.
Anterior Tibialis Tendon Repair
Anterior tibialis tendon repair is a surgery performed to repair a torn or ruptured anterior tibialis tendon. The rupture may occur as a result of a degenerative change or a traumatic event where the ankle and foot are pulled down and outwards forcefully, which in turn maximally stretches the tendon, causing it to rupture.
Ankle Ligament Reconstruction
Ankle ligament reconstruction may be performed arthroscopically under general anesthesia. Your surgeon will make small incisions in your ankle. A tiny camera and a few special instruments are inserted through the incisions to repair and strengthen the ligaments.
Ankle Fusion
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.
Posterior Tibialis Tendon Repair
Posterior tibialis tendon repair is a surgery performed to repair an injured or torn posterior tibialis tendon. The tear may occur as a result of a fall or break/dislocation of the ankle.
Bunionectomy
A bunionectomy is a surgical procedure to remove a bunion. A bunion, also called a hallux valgus, is an enlargement of bone or soft tissues around the joint at the base of the big toe that results in the formation of a bump.
Revision Foot and Ankle Surgery
Foot and ankle surgery is performed when injuries or conditions are severe and conservative treatment methods are inadequate. It may involve repairing, realigning, or reconstructing structures in the foot and ankle.
Osteochondral Allograft Transplantation System (OATS) of the Ankle
OATS of the ankle is a surgical procedure to treat Osteochondral Lesions of the Talus (OCL) or Osteochondritis Dissecans (OCD). It involves the transfer of healthy cartilage to replace the damaged cartilage and restore the normal function of the foot.
Foot & Ankle Deformity Correction
Foot and Ankle deformity correction is the repair of the abnormality by restoring the normal alignment of the bones in the foot & ankle, surgically or non-surgically.
Foot Injections
Foot injections are steroids that are injected into your foot to relieve pain and inflammation. Cortisol is a hormone that is produced in the human body and functions to reduce stress and inflammation.
Platelet-Rich Plasma (PRP) Injection
Our blood consists of a liquid component known as plasma. It also consists of three main solid components which include the red blood cells (RBCs), white blood cells (WBCs), and platelets. Platelets play an important role in forming blood clots. They also consist of special proteins, known as growth factors, which help with our body’s healing process. Platelet-rich plasma or PRP is a high concentration of platelets and plasma.