Tarsus and metatarsus Flashcards
What breed may have sesamoids at the tarsometatarsal joint?
How frequently are they reported?
Greyhounds
- Lateral plantar sesamois in 50%
- Small medial intertarsal tarsometatarsal sesamoid 27%
What percentage of tarsal movement occurs at the tarsocrural joint?
90%
List the 6 main articulations of the tarsus
- tarsocrural
- talocalcaneal
- talocalcaneocentral
- calcaneoquartal
- centrodistal
- tarsometatarsal
Proximal intertarsal joint includes talocalcaneocentral and calcaneoquartal joints
Distal intertarsal joint includes the central tarsal and its articulation with the 1st, 2nd anf 3rd tarsal bones
What is the tarsal canal?
A thickening of the plantar fascia medial to the calcanues and plantar to the talus, containing several important structures (plantar brances of saphenous artery and vein, medial and lateral plantar nerves, tendon sheath of flexor hallucis longus
List the three compontents of the medial collateral ligament and specific whether they are taut in flexion/extension/both
Long part
- From medial malleolus to central tarsal bone (and talus and 2nd)
- Taut in extension
Tibiocentral (short)
- Taut in extension
Tibiotalar (short)
- Taut in FLEXION (runs 90 degress to the other two)
- Most substantial component of MCL
List the components of the lateral collateral ligament and specific wheter each component is taut in extension of flexion
Long lateral ligament
- Taut in extension
Calcaneofibular short ligament
- Taut in extension
- Most substantial compontent of LCL
Talofibular (short)
- Taut in flexion
List the three components of the plantar ligaments
Middle plantar ligament
- Base of calcaneus to 4th tarsal and to MT IV and V
Medial plantar ligament
- Sustentaculum tali to central tarsal bone and then to MT joint capsule
Lateral plantar ligament
- Leaves caudal surface of calcaneus and unites with long collateral before attaching to base of MT V
What are the main differences in regards to the ligamentous anatomy of the tarsus?
Only have short collateral ligaments
MCL
- oblique tibiotalar
- straight talocentral
LCL
- Calcaneofibular
- talofibular
What is the main arterial and nervous supply to the tarsus?
- Cranial tibial artery (becomes dorsal pedal and dorsal MT arteries)
- Plantar branch of saphenous artery (medial and plantar)
- Tibial nerve (becomes medial and lateral plantar nerves)
- Common peroneal nerve
- Saphenous nerve (sensation to dorsomedial tarsus and MT)
What is the normal standing angle of the tarsus of the dog and cat?
- Dog: 135 - 145 deg
- Cat: 115 - 125 deg
What are the four patterns of fracture of the calcaneus?
- Midbody
- Slab
- Avulsion
- Salter-Harris I
What breed is perdisposed to calcaneal fractures?
What is a common concurrent injury
List some fixation options
Racing greyhounds
Commonly concurrent central tarsal bone Fx
Fixation options:
- Lag screws
- K-wires
- Pin and tension band
- Lateral bone plate
- Arthrodesis of calceneoquartal joint (avulsion fractures)
What are they 5 types of central tarsal bone Fx?
- Type I: Nondisplaced dorsal slab fracture
- Type II: Displaced dorsal slab Fx
- Type III: Large displaced medial Fx
- Type IV: Medial slab fracture with dorsal slab Fx
- Type V: Comminuted
What breed is predisposed to fracture dislocation of the central tarsal bone?
Border Collies - Associated with a fracture of the plantar process
What are the main considerations when considering repair of shearing injuries?
- Contamination and possible infection
- Loss of vital structures
- Instability
- Is the remaining bone sufficient to attain a function outcome?
If more than 50% of the joint is intact, saving the joint is justified