Pelvic Limb 4 Flashcards
In the rmt, what two muscles have tendons that give off extensor branches in the distal limb?
Medial tendon of LoDE/CDE & lateral digital extensor tendon
What animal has more muscle fiber in the interosseus and what happens as the animal ages?
Rmt; muscle fiber decreases as the animal ages
Where do the extensor branches of the suspensory ligament of digit 3 insert in the rmt?
medial digital extensor tendon
Where do the extensor branches of the suspensory ligament of digit 4 insert in the rmt?
lateral digital extendor tendon
What joints of the distal rmt limb communicate?
Fetlock –> fetlock
Coffin and pastern joints do not communicate with the same joint on the opposite digit
At what point do the suspensory ligaments give off their axial and abaxial extensor branches?
Prior to insertion on the proximal sesamoids
What two sesamoidean ligaments are absent in the rmt?
straight and short sesamoidean ligaments
How many oblique sesamoidean ligaments does the rmt have per digit?
1
Of the two interdigital ligaments, which one is smaller?
proximal
Where are the cruciate sesamoidean ligaments located in the rmt?
On either side of the medial interdigital phalangosesamoidean ligament
Where is the proximal interdigital ligament located in the rmt?
Just distal to the medial interdigital phalangosesamoidean ligament
Where is the distal interdigital ligament located/where does it insert?
Inserts on P2 and P3 - distalmost ligament
What is the relationship bt the SDF tendon, the DDF tendon, and the connecting branch of the suspensory ligament?
SDF tendon and connecting branches meet at the fetlock, forming a cuff through which the DDF tendon can freely pass (cuff completely surrounds the DDF tendon).
What is the deepest soft tissue structure in the distal limb?
Tendon of the suspensory ligament
What ligaments hold the DDF and SDF in place?
annular palmar/plantar ligaments
How many extensor retinacula do the horse and rmt have in the hock?
Horse = 3 (proximal, middle, distal)
Rmt = 2 (proximal, distal)
Only the horse has the middle retinaculum
What maintains flexion and extension as the only range of movement in the hock?
Lateral and medial collateral ligaments
Where is the origin and insertion of the long plantar ligament?
O: calcaneus
I: 4th MT and part of 3rd MT
What is the presumed function of the long plantar ligament?
It is thought to help counteract effects of gastrocnemius tendon insertion - helps to stabilize the hock
Why are the synovial tendon sheaths overlying the lateral digital extensor and long digital extensor tendons at the hock clinically relevant?
They can become inflamed due to trauma or other reasons
What other tendon does the lateral digital extensor tendon fuse with at the hock?
long digital extensor
What joint of the hock is responsible for the majority of flexion and extension?
tarsocrural joint
What are the 4 joints of the hock?
- Tarsocrural (distal tibia + talus)
- Proximal intertarsal (talus + central tarsal bones)
- Distal intertarsal (middle tarsal bones + distal tarsal bones)
- Tarsometatarsal (3rd tarsal bone + 3rd MT)
What does the proximal intertarsal joint communicate with?
Tarsocrural joint sac
What does the distal intertarsal joint communicate with?
Rarely with the proximal intertarsal joint and sometimes with the tarsometatarsal sac
How many injections are needed to treat the hock?
3:
- Tarsocrural –> proximal intertarsal
- Distal intertarsal
- Tarsometatarsal
Which joint pouch of the hock is the largest and what are some characteristics of it?
dorsomedial; is palpable and is used to access the joint
What are the 4 joint pouches of the hock joint?
- Dorsolateral pouch
- Lateral plantar pouch
- Dorsomedial pouch
- Medial plantar pouch
Where is the insertion of the medial cranial tibial tendon in relation to the hock joint pouches?
It is just distal to the dorsomedial pouch
In the horse, which two joint pouches of the stifle communicate regularly?
Femoropatellar and medial femorotibial
In the horse, which two joint pouches of the stifle sometimes communicate?
Femoropatellar and lateral femorotibial
How many injections do you need for stifle anesthesia in the horse?
3
In the rmt, which two joint pouches of the stifle communicate regularly?
Femoropatellar and medial femorotibial
In the rmt, which joint pouches of the stifle sometimes communicate?
Femoropatellar + lateral femorotibial
Lateral femorotibial + medial femorotibial
How many injections do you need for stifle anesthesia in the rmt?
2
What is the primary blood supply to the distal limb?
cranial tibial a.
What is the secondary blood supply to the distal limb in all spp?
saphenous a.
What is another secondary blood supply in the horse?
caudal tibial a.
In the horse, what does the saphenous a. anastomose with?
branch from the distal caudal femoral a.
How are palmar/plantar and dorsal vessels and nerves named in the distal limb?
Superficial = palmar/plantar or dorsal a/v/n Deep = palmar/plantar MC/MT or dorsal MC/MT a/v/n
In the horse, what does the cranial tibial a. become at the hock?
dorsal pedal a.
In the horse, what does the dorsal pedal a. release to the plantar side and what does it join with?
Releases proximal perforating branch that joins with the proximal deep plantar arch
In the horse, after the dorsal pedal a. releases the proximal perforating branch, what is the vessel now called?
dorsal MT III
In the horse, what is the course of dorsal MT a. III?
Migrates laterally in the cannon region bt MT 3 and 4, moves to plantar side bt cannon and splint bones, becomes distal perforating branch.
In the horse, what does the saphenous a. anastomose with at the hock on the plantar side?
caudal tibial a.
In the horse, where does the saphenous a. aplit and what does it give off?
Splits at the tuber calcanei, gives off medial and lateral plantar aa. and medial and lateral plantar MT aa. by way of the proximal deep plantar arch
In the horse, what are the medial and lateral plantar MT aa. deep to?
suspensory ligament
In the horse, what do the medial and lateral plantar MT aa. anastomose with distally?
distal perforating branch of dorsal MT III
In the horse, what do the medial and lateral plantar MT aa. give off at the fetlock after they have anastomosed with the distal perforating branch of dorsal MT III?
medial and lateral digital aa., which then give off their own dorsal branches
In the horse, what is the distal couse of the medial and lateral plantar aa?
They join the medial and lateral branches of the deep plantar MT aa. to then become the medial and lateral digital aa. at the fetlock.
In the rmt, what does the cranial tibial a. become at the hock?
dorsal pedal a.
In the rmt, what does the dorsal pedal a. give off and what does it become after that?
Gives off a proximal perforating branch and becomes the dorsal MT III at the cannon region
In the rmt, what does the dorsal MT III run deep to and where exactly does it run?
Deep to the long digital extensor tendons in the groove made by the fused 3rd and 4th MT bones.
In the rmt, what does the dorsal MT III give off at the distal cannon before the fetlock?
distal perforating branch
In the rmt, what does the dorsal MT III terminate as?
interdigital a.
In the rmt, what does the saphenous a. split into at the hock?
medial and lateral plantar aa.
In the rmt, what do the deep branches of the saphenous a. fuse to form?
proximal deep plantar arch
In the rmt, what does the proximal deep plantar arch give off?
plantar MT aa. II, III, and IV
In the rmt, what is the proximal deep plantar arch deep to?
suspensory ligament
In the rmt, what does the proximal deep plantar arch receive from the dorsal side?
proximal peforating branch
In the rmt, what do the plantar MT II, III, and IV receive at the distal cannon?
distal perforating branch
What is the clinical relevance of the interdigital a. in the rmt?
Need to know its location if performing toe amputations or other sx bc it is a large blood supply to this area.
In the rmt, what is the plantar common digital a. II a continuation of?
medial plantar a.
In the rmt, what is the plantar common digital a. III a branch of and what is important to note about it as it progresses distally?
medial plantar a.; it is NOT connected to the distal deep plantar arch
In the rmt, what is the plantar common digital a. IV a continuation of?
lateral plantar a.
What vessels all come together to form the distal deep plantar arch?
plantar common digital aa. II and IV, plantar MT aa. II, III, and IV, distal perforating branch from dorsal MT III
What does the interdigital a. reinforce on the plantar side of the rmt foot?
plantar common digital a. III
What are the 2 branches of plantar common digital aa. III and IV?
axial and abaxial of each
axial/abaxial proper digital a. III; axial/abaxial proper digital a. IV
