Canine Hindlimb Flashcards
Describe the overall function of the hindlimb.
- Body weight support for caudally positioned structures
- Locomotion – more power and less direction
Briefly describe the innervation, blood supply and venous drainage of the canine hindlimb.
- Innervation via structures of the lumbosacral plexus
- Arterial supply via the femoral artery
- Venous drainage mainly via femoral vein (via saphenous)
What is the function of the pelvic girdle?
Transfers force from the limb through the sacrum and into the trunk.
How does the pelvis attach to the body?
Pelvis attaches to vertebral column through fibrocartilaginous joint at the sacrum/sacroiliac joint. This joint is not synovial and has limited flexibility.
What innervates the hip extensors/abductors of the proximal limb?
Gluteal nerve and sciatic nerve. Sciatic nerve to gluteals and tensor fascia lata, hamstrings and sensory to caudal hindleg.
What innervates the hip flexors of the proximal limb?
Femoral nerve: L4-L6. Iliopsoas, quadriceps, sartorius. Important to allow standing as need to be able to extend stifle.
What innervates the hip adductors of the proximal limb?
Obturator nerve: L4-L6. Pectineus, adductor, gracilis
Describe the structure of the sciatic nerve.
Sciatic nerve splits into tibial and fibular nerves at the popliteal fossa
What does the tibial nerve supply?
Gastrocnemius
Superficial digital flexor
Popliteus
Deep digital flexor
Interosseous muscle
Sensory to plantar distal limb
What does the fibular nerve supply?
Sensory to lateral limb, peroneus longus and dorsal paw
Cranial tibial
Lateral digital extensor
What happens if the fibular or tibial nerves are damaged?
Will affect:
- Hip extension
- Stifle flexion
- Hock flexion and extension
- Digital flexion and extension
Describe the general position of muscles of the hindlimb.
Craniolaterally are the hock flexors and digital extensors, which are innervated by the fibular nerve.
Caudomedially are the hock extensors and digital flexors, which are innervated by the tibial nerve.
What are the roles of extensors and flexors?
Extensors of the digits in the hind limb will flex the hock/carpus. If a muscle travels across of the carpus and digits, it will extend the carpus and digits. Flexors will extend the hock and flex the digits.
What are the 4 autonomous sensory zones in the canine hindlimb? What are their innervations?
- Caudal and laterocaudal thigh supplied by sciatic nerve.
- More cranial and craniolateral portion of the distal limb supplied by fibular nerve.
- Plantar surface of the paw supplied by tibial nerve.
- Sensory innervation palmaromedially by saphenous (femoral) nerve.
Describe the arterial supply and venous return in the canine hindlimb.
Veins mirror arteries unlike forelimb.
- Iliac artery > external iliac artery > femoral artery
- Popliteal artery is a branch and is behind the stifle
- Saphenous artery is a branch that is relatively superficial supplies more distally
Describe vascular access in the canine hindlimb.
Femoral artery – palpated in femoral triangle, feeling pulse from external iliac artery.
Dorsal pedal artery – in distal limb on the dorsal surface of the foot for pulse palpation and arterial blood sampling.
Saphenous vein – venous blood sampling and IV injections. Located across the hock joint.
What is the clinical relevance of the canine forelimb?
Palpable landmarks
Radiographic landmarks
Muscle attachments
Fractures
What is the pelvic girdle and coxofemoral joint?
- Hindlimb attached via the pelvic girdle
- Sacroiliac joint between sacrum of spine and ilia of pelvis
- More secure but less flexible than the forelimb attachment
What is the femoroacetabular joint?
- Hip joint proper
- Ball and socket/spheroidal joint
- Acetabulum is deeper and more bowl like than the rest of the glenoid fossa and is a bonier socket than in the forelimb.
- Not relying so much on muscles and tendons to keep things in place
What is the role of the ligament of the head of the femur?
Ligament of the head of the femur going from the head of the femur into a space in the articular surface of the acetabulum and tethers the hip into the joint.
What is the role of the transverse acetabular ligament?
Transverse acetabular ligament provides greater curvature to the more ventral portion to help enclose the head of the femur within the joints.
Where does the ligament of the head of the femur attach?
Dorsal acetabulum has articular cartilage, the lunate surface. Ligament of the head of the femur attaches in the acetabular fossa. In the dog, the transverse acetabular ligament completes the ‘bowl’.
What does hip joint laxity lead to? How is it caused?
Causes dysplasia.
- Joint incongruence
- Weak ligament of the head of the femur
- Stretched joint capsule, causing joint subluxation
What are the roles of lateral and medial muscles?
Lateral muscles may also abduct the limb in addition to flexion and extension.
Medial muscles may also adduct the limb in addition to flexion and extension
Name the primary hip extensors.
Cranial to hip: gluteals – extend and abduct
Caudal to hip: hamstrings – extend
Name the hip flexors.
Ilopsoas
Biceps* femoris
Sartorius
Tensor fascia lata
Describe positions of the gluteal muscles.
- Most of the gluteal group (middle and deep) attaches on the gluteal surface of the ileum.
- Superficial gluteal attaches at the sacrum and coccygeal vertebrae. Insets proximally on femur. If shortened, the limb bone is rotated around the joint centre and can be abducted.
- Middle gluteal is the largest hip muscle, is a major hip extensor and is a minor abductor.
- Deep gluteal is the deepest craniolateral muscle, lies adjacent to craniodorsal joint capsule and is an abductor of the hip and internal rotator of the hindleg.
Describe the position of the hamstring muscles.
- Biceps femoris is most lateral and is a triarticular muscle and crosses al of the joints of the limb.
- Semitendinosus is more medial than biceps femoris
- Semimembranosus is the most medial
Describe the position and structure of the rectus femoris.
Comes across hip joint and travel across quadriceps group and attaches to the patella and envoy onto the patella ligament onto the proximal end of the tibia.
Describe the position and structure of the sartorius muscles.
2 bellies coming from iliac wings, caudal and cranial and insert medially on distal end of the femur.
Describe the position and structure of the iliopsoas.
Iliacus and psoas major originate along the spine and along the internal surfaces of the pelvis and inserting distally on the proximal end of the femur.
Name the 3 abductors of the hip and their innervation.
Innervated by obturator nerve.
- Gracilis – large, medial limb and oval shaped
- Pectineus – smaller
- Adductor muscle – large muscle but superficially looks small. Helps to keep limb beside the body and prevent splaying.
Briefly describe the stifle joint.
- Joint between femur and tibia, interaction with patella in tendon of quadriceps muscles
- Primarily moves in flexion and extension
- Complex support structures
- Single most commonly affected joint for lameness in dogs
- Cranil cruciate disease, meniscal injury and patella luxation
Describe the structure and function of the menisci.
- Medial and lateral
- Crescent/wedge shaped fibrocartilage pads
- Provide shock absorption, reduce friction
- Medial anchored to tibia
- Lateral anchored to tibia and femur, less likely to be damaged
What is the function of the medial and lateral collateral ligaments?
Prevent medial and lateral movement of the limb
Describe the structure and function of the cruciate ligaments.
- Cranial and caudal cruciate ligaments. Cross over each other over the stifle joint. Cranial inserts caudally on the femur and caudal inserts cranially on the femur.
- Prevent cranial and caudal translation of the tibia relative to the femur
Describe cranial cruciate ligament rupture.
- Most common cause of stifle lameness
- Degenerative changes to ligament. Weakened ligament causing rupture. Can have genetic causes or be purely traumatic.
- Meniscal injury associated with CrCL rupture particularly medial meniscus due to attachments, as it will likely be crushed into femoral condyles.
- Rupture allows cranial translation of tibia across femur.
- Medial meniscus closely attached to tibia and does not move with femur, so is damaged
- Lateral meniscus us able to move with the femur so is less likely to be damaged
How are the cruciate ligaments and the proximal tibial articular surface linked in the healthy dog?
- Backwards slope – tibial plateau angle
- Femur when it lands on the tibia tends to slide backwards along the proximal surface of the tibia and the tibia will be pushed forward by the downward force of the femur.
- Fine in a healthy dog, as cruciate ligaments hold everything in place.
- So when the cranial cruciate ligament is damaged/torn, tibia translation force is allowed to continue.
What is the test for cruciate ligament rupture?
Cranial drawer test - Produce cranial tibial thrust using hands by holding on to the femur and tibia and see if you can cranially translate tibia relative to the femur. Repeat with stifle in extension and 30˚ flexion to detect partial tears.
Name the superficial support structures.
Medial and lateral collateral ligaments – on either side of the menisci
Patellar tendon and ligament support cranially
Describe the tendons and ligaments surrounding the patella.
Patellar tendon is the structure that comes down from the muscles of the quadriceps femoris:
- Within the tendon sits the patellar
- Either side there is patellofemoral ligaments that hold this in place but patella is able to rotate around the joint as the femur flexes and extends relative to the tibia.
- Distal to the patella is the patella ligament (debate on whether tendon or ligament), a continuation of patella tendon, where the quadriceps femoris muscles insert.
Name the 3 compartments of the stifle synovial.
All freely communicate:
- Femoropatellar
- Lateral femorotibial
- Medial femorotibial
What are the muscles of the canine stifle joint?
Predominantly a hinge joint:
- Major stifle flexors: hamstrings
- Minor stifle flexors
- Major stifle extensors: quadriceps
Name the muscles of the hamstring and their insertions.
Biceps (rectus part of quadriceps) femoris – also has insertion with calcaneal tendon
Semitendinosus – second smaller insertion with calcaneal tendon
Semimembranosus – no insertion on calcaneal tendon
Name the minor stifle flexors and their innervation.
Tibial nerve
Gastrocnemius
Superficial digital flexor
Popliteus
Describe the gastrocnemius.
- Orginate over febellaes on femur
- Primarily hock extensor
- Minor stifle flexor
- Inserts on calcaneal tendon
Describe the superficial digital flexor.
- Primarily hock extensor/digit flexor
- Minor stifle flexor
- Inserts on digits
Describe the popliteus.
- Stifel flexor
- Internal rotator of lower limb
- Originates laterally on femur and medially on tibia so internally rotates and pronates tibia
Name the 4 main bellies of the quadriceps.
Rectus femoris
Vastus lateralis
Vastus intermedius
Vastus medialis
Describe the structure and function of the quadriceps.
- Large powerful muscles
- Primarily stifle extensors
- All form common tendon on patella
- Insert on tibial tuberosity via patella tendon.
Describe the individual muscle bellies of the quadriceps.
Vastus lateralis, medialis and intermedius originate on the lateral, cranial and medial femur and form a ‘cup’ shape cranially.
Rectus femoris runs distally in this cup before the tendons of all 4 muscles merge to insert on the patella.
Name the different joint levels in the tarsus.
- Tarsocrural – between tarsus and tibia
- Talocalcaneal – between talus and calcaneus
- Proximal intertarsal
- Distal intertarsal
- Tarsometatarsal
Where is the range of motion in the tarsus?
Almost all the range of motion is in the tarsocrural joint.
What is the clinical relevance of the tarsus?
Tarsal fractures and causing bones of the tarsal to become mobile or dislodging ligaments and dislocations. Common in race dogs.
Name the hock support structures.
- Almost entirely a hinge joint at the tarsocrural joint. Very strong collateral ligaments. Long and short portions in order to be taut at different positions of joint flexion/extension.
- Plantar tarsal ligaments similar to carpus
Describe the structure and function of the plantar tarsal ligaments.
Several individual ligaments but functionally one fibrocartilage mass/plantar tarsal fibrocartilage.
Provides resistance to hyperextension of proximal intertarsal, distal intertarsal and tarsometatarsal joint.
What do injuries to the hock cause?
Hyperextension of proximal intertarsal, distal intertarsal and tarsometatarsal joint
What happens when the collateral ligaments are injured?
Mediolateral instability due to medial/lateral displacement.
What happens when the plantar ligaments are injured?
Hyperextension of the proximal intertarsal joint, distal intertarsal joint and tarsometatarsal joint.
What are the hock flexors/digital extensors innervated by?
Fibular nerve
Name the hock flexors/digital extensors.
Cranial tibial
Long digital extensor – goes to all the digits in the hindlimb, much like the common digital extensor in the forelimb
Long digital extensor tendon - crosses stifle joint laterally
Fibularis (peroneus) longus
Lateral digital extensor (very small)
What are the hock extensors innervated by?
Tibial nerve
Name and describe the hock extensor muscles.
Gastrocnemius
Superficial digital flexor – inserts on P2 of each of the digits
Deep digital flexor – inserts on P3 of the digits
What structures insert on the calcaneal tuberosity?
More strands of tendon that insert with tendons of gastrocnemius and the superficial digital flexor on the calcaneal tuberosity.
What is the purpose of structures of the tarsus inserting on the calcaneus?
The entire portion of tarsus from here distally acts like a seesaw and all the structures inserting on the calcaneus increases the lever arm around the joint’s centre of motion.
What happens when the common calcaneal tendon is ruptured?
Varied degrees of plantigrade stance. Depends on which part of the common calcaneal tendon are ruptured
What type of joint is the pelvis to the vertebral column/sacrum?
Cartilaginous
What important function does the greater trochanter serve?
Muscle insertion for the gluteal muscles Look at the acetabular articular surface.
Why is the articular smooth surface only in a horseshoe shape on the dorsal, cranial and caudal surfaces? Why is the central part (acetabular fossa) not continuous and smooth like the rest?
These surfaces are the areas where the weight bearing is transferred through the hip. The central depression is where the ligament of the head of the femur is attached
Which ligament in the stifle joint of dogs is most important in resisting cranial movement/translation of the proximal tibia in relation to the distal femur?
Cranial cruciate ligament
Which muscles contribute to the common calcaneal tendon?
Semitendinosus
Biceps femoris
Gracilis
Gastrocnemius
Superficial digital flexor
What blood vessel in the hindlimb is most commonly used for taking a pulse in dogs?
Femoral artery
What nerve innervates the extensors of the stifle?
Femoral nerve
A dog is unable to flex its hock or extend its digits and has sensory deficits to the lateral aspect of the limb and dorsal paw. What nerve is most likely affected?
The peroneal nerve
It supplies motor innervation to the flexors of the hock and the extensors of the digits. It supplies sensory innervation to the lateral hindlimb and dorsal paw.
The peroneal nerve is also a branch of the sciatic nerve, so if the sciatic nerve was affected in a more proximal injury, there would also be deficits relating to the tibial nerve.
The tibial thrust test is used to test the integrity of what support structures in the hindlimb?
Cranial cruciate ligament
