Foot and Ankle Flashcards
What joint does the “ankle” refer to?
Talocrural Joint
Rearfoot: bones and joints?
Talus, calcaneus, subtalar joint
Midfoot: bones?
Tarsal bones aside from calcaneus and talus
Forefoot: Bones?
Metatarsals, phalanges
Osteology of the Fibula
Proximal head, distal lateral malleolus, takes on 10% of the body weight
Osteology of the Distal Tibia
Expands distally to accommodate load (90% of body weight), distal medial malleolus, torsion of long axis approx 20-30 degrees (causing toe-out)
What are the 7 Tarsal Bones?
Talus, calcaneus, navicular, cuboid, medial/lateral/intermediate cuneiforms
Osteology of the Talus
Joins foot to leg, does not have muscular attachments, 70% covered in articular cartilage, forms joint with ankle mortis
Trochlea/Talar dome, head (articulates with navicular), articular facets (inferior surface to articulate with calcaneus)
Osteology of the Calcaneus
Largest tarsal bone, attachment for Achilles
Osteology of Navicular
Medial side of foot, navicular tuberosity (attachment site for tibialis posterior)
Cuboid
6 sides, 3 articulate with adjacent tarsal bones
Osteology of the Metatarsals
Concave on plantar side, concave base (proximal), shaft, convex head (distal)
Osteology of Phalanges
14 in total, concave base (proximal), shaft, convex head (distal)
Pronation
Dorsiflexion, eversion, abduction
Supination
Plantarflexion, inversion, adduction
Proximal Tibiofibular Joint
Head of fibula with lateral aspect of tibia, synovial joint, firm articulation to ensure force from biceps Femoris and LCL are transferred effectively from fibula to tibia
Distal Tibiofibular Joint
Syndesmosis (fibrous), ligament ours support to limit movement (interosseus ligament, ATFL and PTFL), limited movement (restricted movement associated with pain)
Talocrural Joint
Articulation between trochlear dome and sides of talus with cavity formed by distal tibia and both malleoli
Must be stable!
90-95% of compressive force passes through
3mm of cartilage can compress by 30-40%
Capsule reinforced by ligaments
Deltoid Ligament
Also called MCL, fan shaped, limit excessive eversion, checks extreme ranges of motion
ATFL, PTFL, CFL
Controls varus (inversion) stress, weaker and more prone to injury
ATFL- inversion with PF
CFL- inversion with DF
PTFL- stabilizes talus in mortise
Osteokinematics at Ankle Joint
1 DOF at talocrural
Oblique axis
Close packed= DF
Dorsiflexion occurs with slight abduction/eversion
Minimum 10 degrees necessary, normal ROM= 10-20
Plantarflexion occurs with slight adduction/inversion
Normal ROM= 20-50
Axes for Motion at Talocrural Joint
Abd/add= vertical axis DF/PF= ML axis Ev/Inv= AP axis