Comparative Hindlimb Flashcards
What is the function of the hindlimb stay apparatus ?
Ability to lock weight bearing limb combined with front stay apparatus to allow horse to sleep whilst standing
What are the key components of the HL stay apparatus?
Stifle- patella and patellar ligaments
Hip/stifle/hock- prevention of collapse into flexion
Hock- reciprocal apparatus
Digits- suspensory apparatus of the fetlock
How is the patella ‘locked’?
Stifle extends, patella moves proximally and rotates medially, engages horizontal, tubercle of medial trochlear ridge between middle and medial patellar ligaments
What makes up the reciprocal apparatus?
Peroneus tertius
Superficial digital flexor- fibrous bands
What is the MTP joint?
Metatarsal pharyngeal joint
What do the MTP/PIP/DIP do in the stay apparatus?
Prevention of hyperextension
What are the different distal sesamoidean ligaments and what joint are they in?
Straight Oblique Short Cruciate Found in the MTP
What are the three annular ligaments?
Proximal
Proximal phalanx
Distal
What are the 4 bones of the pelvis?
Ilium, ischium, pubis, acetabulum
What are the species differences between the wing of the ilium?
Dog and Pig- vertical orientation, flat or convex on cranial margin
Horse and ruminants- horizontal orientation, concave cranial margin
What are the differences between tuber ischium between species?
Cow- trifid (3 way projection)
Sheep less distinct but still triffid
What is palpable in ruminants?
Tuber sacrale
Tuber coxae
Tuber ischium
How does the sacrum vary between species?
Hose, cow and goat- 5 fused sacral vertebrae
Pig/sheep- 4
Dog- 3
Cow- dorsal spinous process of sacrum fuse as ages
Horse- dorsal spinous processes not fused
How does the sacrotuberous ligament vary between species?
Dog- fibrous band, S3 to tuber ischium
Cow and horse- fibrous sheet, sacrum to dorsal ilium/ischium, forms lateral wall of pelvic cavity, protects and allows passage of nerves
What is the differences between the hip joint between species?
Cow, horse and pig- same features as dog, ligament head of femur
Horse- accessory ligament
Cow- acetabulum has divided articular surface
Describe the structure and function of the accessory ligament?
Continuation of the prepubic tendon
runs from pecten under transverse ligament
Tension due to weight of abdominal contents
What is different about a cows femur compared to other species?
Medial trochlear ridge larger than lateral- equal in other species
No tubercle
3 patellar ligaments
No patellar locking mechanism
How does the tibia and fibula vary between species?
Pig- fibula complete and separate from tibia
Ruminants- remnant of fibula proximally fused distally joined by ligament
Horse-proximal half fused to tibia and distal fused
What is the differences in the tarsus between species?
Pig- all 7 bones present
Ruminant- 5 central and 4 fused, 2 and 3 fused
Horse- 6 bones, 1 an 2 fused
Why can cows kick laterally?
Rotation possible at proximal intertarsal joint
