foot and ankle Flashcards
anatomical regions of foot
- The hind-foot : talus; calcaneus
- The mid-foot: navicular; cuboid; 3 cuneiform
- The fore-foot : metatarsals; phalanges
how many bones and what are they divided into
26 and divided into tarsals, metatarsals and phalanges
tarsals
divisions
make up the hindfoot and midfoot - a set of seven irregularly shaped bones situated proximally
metatarsals
divisions
long bones of the forefoot, forming the arch and connecting the tarsals to the phalanges. Numbered 1 through 5 starting from the medial side
phalanges
divisions
part of the forefoot, the bones of the toes
what do bones of foot provide
- mechanical support for the soft tissues
- helping the foot withstand the weight of the body whilst standing and in motion.
what is the tarsus
proximal region of the foot and consists of seven tarsal bones
organised into 3 rows:
prox- talus(overlap calcaneus)/ calcaneus (tall one)
intermediate- navicular (under talus)
distal- cuboid (articulate w 4&5 toe)/ three cuneiforms (articulate w 1,2&3 toe)
acryonym: the cock never comes tidially
talus
- Most proximal bone of the foot
- 70% is covered with hyaline cartilage as it articulates with other bones
- Connects to the calcaneus on the underside through the subtalar or talocalcaneal joint
- Connects distally to the navicular through the talonavicular joint
- Relatively poor blood supply – injuries take greater time to heal
- Has three parts: body, head, and neck
- body is roughly square and topped by the dome which connects the talus to the lower leg at the ankle joint
- Talar neck is not covered with cartilage and is the entry point for blood supply
calcaneus
- known as the heel bone
- largest bone in the foot, and along with the talus, it makes up the hind-foot
- The anterior, middle, and posterior facets on the superior surface of the calcaneus allow the talus to sit on top of the calcaneus, forming thesubtalar joint
- connects to thecuboid boneto form thecalcaneal-cuboid joint
what are the tarsal bones
Navicular:
* Distal to the talus and connects with it at the talonavicular joint
* Distal aspect connects to the cuneiforms
* Poor blood supply
* Medially the navicular tuberosity is the main attachment site for the posterior tibial tendon
Cuboid:
* Square shaped bone on the lateral aspect of the foot
* Distal aspect of the calcaneus articulates with the cuboid at the calcaneocuboid joint
Cuneiforms:
* Three cuneiform bones: medial, intermediate, and lateral cuneiforms
* Provide stability
* Plantar and dorsal ligaments connect to the cuneiforms
what are metatarsals
- five long bones of the forefoot, between the tarsals and phalanges.
- theyare numbered 1-5 (medial to lateral
- Each metatarsal has a similar structure: convex dorsally and consist of a head, shaft, and base (distal to proximal)
- has 3/4 articulations:
1. proximally- tarsometatarsal joints (between the metatarsal bases and thetarsal bones)
2. laterally– intermetatarsal joint(s) – between the metatarsal and the adjacent metatarsals
3. distally– metatarsophalangeal joint – between the metatarsal head and the proximal phalanx
phalanges
- 14 phalangesare the bones of the toes
- second to fifth toes all have proximal, middle and distal phalanges whilst the great toe has only 2: proximal and distal phalanges
- are similar in structure to the metatarsals, each phalanx consists of a base, body and head
joints of the foot and ankle
that allow for movement, stability, and weight-bearing
- Talocrural – tibiotalar/ankle joint - formed by the tibia, fibula, talus- main joint of the ankle
- Talonavicular joint– articulation between the head of the talus and posterior navicular
- Naviculocuneiform joint– compound joint, articulations between the navicular and 3 cuneiforms
- Tarsometatarsal joint – Lisfranc joint – between the tarsal and metatarsal bones
- Metatarsalphalangeal joints – connects the metatarsals and proximal phalanges
- Calcaneocuboid joint – formed by distal surface of the calcaneus with the proximal cuboid
- Subtalar joint – (talocalcaneal joint) between the talus and calcaneus
articulation of the ankle joint
- Talocrural joint is a complex synovial hinge joint
- Distal tibia and fibula form a structure called the MORTISE and the talus sits within it
- The inferior tibiofibular joint stabilises the talocrural joint by tightly securing the tibia and fibula together
- the joint is reinforced by strong ligaments
main ligaments of the ankle
can be divided to medial and lateral
MEDIAL:
* called the deltoid ligament;
- resists eversion
D - posterior tibiotalar ligament
D - anterior tibiotalar ligament
S - talonavicular
S - talocalcaneal ligament
LATERAL:
* are located on the fibula side of the ankle
* PTFL (The Posterior Talofibular Ligament) connects posterior talus to the fibula
* ATFL (The Anterior Talofibular Ligament) connects the anterior talus to the fibula
* CTFL (The Calcaneofibular Ligament) connects the calcaneus to the fibula
* resists inversion