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.