Orthopaedic Procedures | Anatomy of the Foot and Ankle

The foot is an incredibly complex part of the body. The following sections will touch on the various tissues that make the whole foot.


Skeleton

 

The two bones tibia and fibula come together with talus to form a secure mortise joint.

 

The mortise and tenon construct is well known to carpenters and craftsmen who use this joint in the construction of everything from furniture to large buildings because it is so stable.

 

The talus and calcaneus are the two hindfoot bones that are connected at the subtalar joint. The ankle joint allows the foot to bend up and down. The subtalar joint allows the foot to rock from side to side.

 

The next group of bones are tarsal bones that work together. These bones are very interesting in the way they fit together. When the foot is twisted inwards by the muscles of the foot and leg, these bones lock together and form a very rigid structure. When they are twisted outwards, they become unlocked and allow the foot to conform to whatever surfaces the foot is contacting.

 

The 5 long bones of the foot called the metatarsals which are joined to the tarsal bones. There is a fairly rigid connection between the two groups without much movement at the joints.

 

Finally, the phalanges are the group of bones that make up the toes. The joints between the metatarsals and the phalanges are called the metatarsophalangeal joints. These joints form the third rocker of the foot and allow for the push off for a normal walking pattern.

 

The big toe or hallux is the most important toe for walking, and the first metatarsophalangeal joint is a common area for problems.


Important Soft Tissue

 

The important soft tissues of the foot and ankle include ligaments, tendons, nerves, and blood vessels.

 

The main blood supply to the foot is by posterior tibial artery that runs behind the medial malleolus and to some extent by the anterior tibial artery. The main nerve supply is through the posterior tibial nerve and anterior tibial nerve that runs alongside the arteries. Of course there are other nerves and arteries that supply rest of the foot.

 

The calf muscle becomes the Achilles tendon and is attached distally to the os calcis. The posterior tibial tendon is attached to the inner part of the foot and the peroneal tendons are attached to the outer part of the foot. These tendons hold the foot straight whilst the Achilles tendon provides the push-off. The tibialis anterior tendon dorsiflexes the foot. The ligaments statically control the joints whilst the tendons provide the power for propulsion.


History and Physical Examination

 

The important symptoms of foot pathology are pain. The doctor may ask:

 

to localize the pain
was there any injury
character and duration of the pain
and problems with footwear
This is followed by a physical examination of your feet, legs, how you walk, and the SHOES you wear.

 

X-ray

 

X-rays are important in detecting bone and joint problems such as fractures and deformities.


MRI Scan

 

These are good at detecting soft tissue problems such as ligaments, joint surface, tendons etc. This in conjunction with clinical examination help in the overall management.


CAT Scan

 

These scans show slice of bones and to some extent soft tissues, and are also helpful in picking up subtle fractures. They also help to define bone tumours and diseases affecting the bones.


Laboratory Tests

 

Blood test and other laboratory tests are done in some infective conditions and in diabetes.

 

Common Foot and Ankle Syndromes

 

Ankle Sprain/Instability
Ostechondritis Dissecans
Posterior Tibial Tendinitis/Rupture
Plantar Fasciitis
Tarsal Tunnel Syndrome
Bunion/Hallux Valgus
Hallux Rigidus
Bunionette
Morton's Neuroma
Clawtoe/Hammertoes
Ingrown Toenail
Achilles Tendon Problems