Ankle And Foot Flashcards
Structure of the leg
Brief overview of the tibia and the fibula:
Tibia - weight bearing bone of the leg
Much larger than fibula
Dismally - it forms medial malleollus
Fibula - much smaller
On lateral side of leg
Shaft of bone much smaller than tibia
Distally, forms lateral malleollus
Tibia and fibula linked by interosseous membrane
Structure of the leg
Brief overview of ankle and foot:
Ankle - involves talus of the foot and the distal tibia and fibula of the leg
Foot - distal t ankle joint
Consists of tarsal bones, the metatarsus and the digits
Foot has superior surface - dorsum
And inferior surface - sole
Function of the foot and ankle region:
Provides stable base of support
Rigid lever for propulsion
Absorbs shock of weight bearing bone
Conforms and adapts to uneven surfaces
Important role in sensation/proprioception/balance
Allows adjustment of line of gravity in standing
Provides propulsion and restraint in walking
Bones and bony landmarks
Distal tibia -
Rectangular in shape
Bone protuberance on medial side is the medial malleollus
Lower surface and medial malleollus articulate with one of the tarsal bones (talas) to from a large part of the ankle joint
Lateral surface has a triangular notch - articulates with fibula
Bones and bony landmarks
Distal fibula -
Bony protuberance on lateral side of fibula is the lateral malleollus
Medial surface of lateral malleollus articulates with the talus
Malleollar fossa
Triangular area articulating with the fibula notch of the tibia
What are the three groups of bones in the foot?
Tarsal bones
Metatarsals 1-5
Phalanges
What makes up the tarsal bones:
Proximal group - talus and calcaneus
Intermediate tarsal bone - navicular
Distal group - cuboid, cuneiforms (medial, intermediate and lateral)
Tarsal bones: talus -
Head: articulates anteriorly with navicular
Articulates inferiorly with calcaneus
Neck: deep groove (sulcus tali)
Body: (superior aspect) upper trochlear surface, medial surface and lateral surface
(Inferior body) large, oval concave facet for articulation with the calcaneus
Tarsal bones: calcaneus -
Sits under and supports talus
Largest tarsal bone, elongate, irregular box shaped
Posterior surface has upper, middle (where Achilles tendon inserts) and lower aspect which has calcaneal tuberosity.
Lower is weight bearing area of heel.
Medial surface - sustentaculum tail - supports superior part of talus head
Tarsal bones: navicular -
Intermediate tarsal bone
Medial side of foot
Articulates: posteriorly with talus
Anteriorly with cuneiforms
Laterally with cuboid
Prominent tuberosity - tibialus posterior tendon attaches here
Possible to have an accessory navicular - can be asymptomatic or at risk of kohlers disease (inability to weight bear)
Tarsal bones: cuboid -
Lateral aspect of foot
Articulates: posteriorly with calcaneus
Medially with lateral cuneiform
Anteriorly with the bases of the lateral two metatarsals
Tarsal bones: cuneiforms -
3 cuneiform bones - lateral, intermediate and medial cuneiform bones
Articulate - with each other
Posteriorly with navicular bone
Anteriorly with base of medial three metatarsals
Laterally to cuboid
Metatarsals:
Five in the foot
Long bones
Umber 1-5 from medial to lateral
Each metatarsal consists of head shaft and base
Base of metatarsal V has a prominent tuberosity - projects posteriorly
Sesamoid bones:
Two sesamoid bones articulate with head of metatarsal I embedded within tendon of flexor hallucis brevis
Phalanges:
Each toe has 3 phalanges
Proximal, middle and distal
Except great toe - only has two
Each phalanx consists of - head (non-articular, flattened to tuberosity), shaft and base.
Interosseous membrane -
Tough, fibrous sheet of connective tissue
Spans the distance between border of tibia and fibula shafts
Collagen fibres descend obliquely
Provides attachment for muscles
Sperates anterior and posterior compartments
Classify
Superior tibiofibular joint -
And state movements available
Synovial plane joint
Articular surfaces:
Proximal - head of fibula
Inferolateral surface of lateral condyle of tibia
Joint capsule - reinforced by anterior and posterior ligaments of fibula head
Movements - small rotational movements during ankle DF/PF and gliding
Classify
Inferior tibiofibular joint -
And movements available
Distal
Fibrous syndesmois/fibrous joint
Articular surfaces - fibular notch on lateral aspect of distal tibia and medial fibula
Ligaments - anterior and posterior inferior tibiofibular ligaments
Traverse tibiofibular ligament
Movements - small rotational movements during ankle DF/PF and gliding
Ankle joint (talocural)
Classify, joint capsule and movements available -
Synovial hinge joint
Distal fibula and tibia create deep bracket shaped socket
Articular surfaces - covered in hyaline cartilage
Articular surface of talus
Distal end of tibia and fibula
Joint capsule - enclosed by a synovial membrane which is covered by fibrous membrane
Ligaments - medial (deltoid) ligament and lateral ligaments - joint more stable when foot in dorsiflexion
Movements - 1 degree movement
Dorsiflexion - 20-30 knee extended and 35 knee flexed
Plantar - approx 50 degrees
Sub talar joint
Classify, joint capsule and movements available -
Distal to ankle joint
Synovial plane (modified saddle) joint
Articular surfaces- large posterior concave facet on inferior surface of talus
Corresponding posterior convex facet on superior surface calcaneus
Joint capsule - enclosed b synovial membrane which I covered by fibrous membrane
Ligaments - capsule supported medial, laterally and posteriorly by talocalcanel ligaments
Joint stabilised by Interosseous talocalcaneal ligament
Movement - inversion(45-60)
Eversion (15-30)
Mid tarsal (transverse) joint
Classify, and movements:
Synovial ball and socket joint
S shaped comprising of two smaller joints
- talocalaneonavicular joint
- calcaneocuboid joint
Movement - gliding and rotation
Involved with inversion/eversion and pronation/supination (combined with sub-talar joint for P and S to occur)
Talocalcaneonavicular joint
Calssify, and joint capsules -
Synovial ball and socket joint
Articular surfaces - navicular, head of talus, sustentaculum tali and plantar calcaneonavicular joint
Joint capsule - reinforced by ligaments
- Interosseous talocalcaneal (posterior)
- talonavicular (superior)
- bifurcate ligament (lateral)
- plantar calcaneonavicular ligament (inferior)
Calcaneocuboid joint
Classify:
Synovial saddle
Articular surfaces - facet on anterior surface of calcaneus and the corresponding facet on posterior surface of the cuboid
Ligaments -bifurcate ligament
Long plantar ligament
Short plantar ligament
Tarsometatarsal joints
Classify and movements -
Synovial plane joint
Articular surfaces - between metatarsal bones and adjacent tarsal ones
Ligaments - bifurcate ligament
Long plantar ligament
Short plantar ligament
Movement - gliding movements only