88 - Tibiofibular and Ankle Joints Flashcards
Weight bearing bone of the leg
Tibia
Role of fibula
Muscle attachments (non-weight-bearing)
Only muscle that articulates with fibula
Biceps femoris
Number of muscles originating from fibula
Eight
Common association with fracture of either tibia or fibula
Tend to fracture both tibia and fibula together (as both bones are joined strongly)
Part of tibia most vulnerable to fracture
Junction between inferior and mid 3rds of bone (where bone is the thinnest and has poorest blood supply)
Features of superior tibiofibular joint
1
2
A plane synovial joint, which allows some gliding movement
Has anterior and posterior tibiofibular ligaments (reinforce the joint)
Features of inferior tibiofibular joints
1-4
- Fibrous joint (syndesmosis), which prevents tibia & fibula from separating (in weight bearing)
- Has anterior, posterior and interosseous ligaments
- Large role is shock absorption
- Can be separated (diastasis)
How can inferior tibiofibular joint be injured?
Falling from a height onto leg (diastasis, which is separation of syndesmosis (fibrous reinforcement of joint)
Basic layout of bones of the foot
Similar to hand and wrist, but first two bone s(calcaneus, talus) are orientated vertically
Bone of foot that articulates with tibia
Talus
Bone of foot that is heel
Calcaneus
Tarsal bones
1-5
Calcaneus Talus Navicular Three cuneiform bones Cuboid
Metatarsal at risk of fracture
Second metatarsal
Why is the second metatarsal at risk of fracture with repeated force?
Slender.
Connected to third metatarsal (limited movement).
‘March fracture’
Phalanges of foot
Two in hallux (big toe)
Three in other toes.
Sesamoid bones under first metatarsal
Two under first metatarsal, which form a channel
Sesamoid bones of foot
All over foot, can be mistaken for a fracture
Articulations of talus bone
1
2
3
Ankle joint above Subtalar joints (below Midtarsal joint (in front, talocalcaneonavicular joint and calcaneocuboid joint)
Type of joint that the ankle is
Hinge
Shape of ankle joint
‘Mortice’ formed between malleoli of tibia and fibula.
Mortice is deepened posteriorly by inferior transverse ligament.
Talus inserts into mortice
Angle of ankle joint
Oblique angle (so with plantarflexion, sole of foot points medially)
Ligaments of ankle joint
Medial side has a strong ligament, which is rarely injured.
Lateral ligament is made of three discrete bands (anterior and posterior talofibular and calcaneofibular).
Most common foot position of ankle injury
Plantarflexion with foot inverted (sole facing inwards)
Subtalar joint
Between talus and calcaneus
Midtarsal joint
Between calcaneus, talus and naviculus.
Joints between metatarsals
1
2
3
Tarsometatarsal joints
metatarsophalyngeal joints
Interphalyngeal joints
Name of canal separating posterior surface of subtalar joint
Sinus tarsi
Ligament of subtalar joint that resists inversion and eversion
Interosseous tali-calcaneal ligament
Movements at subtalar joint
Inversion and eversion (inversion is greater than eversion)
Movements at midtarsal joints
Pronation (eversion + abduction)
Supination (inversion + adduction)
Movements of metatarsophalyngeal joints
Same as metacarpophalyngeal joints:
Flexion, extension, adduction, abduction
Movements of interphalangeal joints of foot
Same as those of hand
Flexion and extension
Plantar aponeurosis
1
2
3
Between calcaneus and heads of the metatarsals.
It binds skin of foot for grip and protection.
Maintains longitudinal arches of foot.
Clinical significance of plantar aponeurosis
Plantar fasciitis (inflammation), which can lead to bony changes in plantar aponeurosis (bony spurs), which are very painful
