Canine hindlimb 2 PDF

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1 Lecture 2 15.Canine hindlimb 2Muscles of the stifle Stifle flexors: Biceps femoris: - Largest and most lateral muscle- Main effect on the stifle is flexion- Inserts with the calcaneal tendon Semitendinous: - Has a second smaller insertion on the calcaneal tendon Semimembranous: - Most medial- Stif...

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1

Lecture 2

Canine hindlimb 2 Muscles of the stifle • Stifle flexors: 1. Biceps femoris: - Largest and most lateral muscle - Main effect on the stifle is flexion - Inserts with the calcaneal tendon 2. Semitendinous: - Has a second smaller insertion on the calcaneal tendon 3. Semimembranous: - Most medial - Stifle flexion - No insertion on the calcaneal tendon • All innervated by the sciatic nerve • Minor Stifle flexors: 1. Gastrocnemius: - Primarily hock extensor - Minor stifle flexor 2. Superficial digital flexor: - Primary hock extensor and digital flexor 3. Popliteus: - Stifle flexor and internal orator of the lower limb - Originates laterally on the femur and medially on the tibia • All innervated by the tibial nerve • Stifle extensors: • Quadriceps group • Large powerful muscles • Primarily stifle extensors 1. Rectus femoris : also a hip flexor 2. Vastas lateralis 3. Vastas intermedius 4. Vastas medialis • All form common tendon on the patella and insert on tibial tuberosity via the patella tendon • All inverted by the femoral nerve Stifle joint • Single most commonly affected joint for lameness in dogs • Cranial cruciate disease • Meniscal injury • Patella luxation • Cruciate ligaments: - Degenerative changes to ligament will cause weakness and eventually rupture - There are both cranial and caudal cruciate ligaments - They both keep the tibia in line with the femur • Menisci: - Crescent shaped fibrocartilage - Medial and lateral menisci which are wedge shaped to restrain the two convex bone surfaces - Fixation differs between the medial and lateral menisci • Patella support structures: 1. Quadriceps muscle 2. Femoropatellar ligament

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Lecture 2

3. Patella tendon 4. Tibial tuberosity The hock joint • Complex joint with several bones • There are different joint levels 1. Tarsocrural = between the tarsus and the tibia/fibula 2. Talocalcaneal = between the talus and the calcaneous 3. Proximal intertarsal = between the talus and the cranial/ 4th tarsal bones 4. Distal intertarsal = between the central and the 2nd/3rd tarsal bones 5. Tarsometarsal = between the tarsal bones and the metatarsals Muscles of the hock and the digits • Hock flexors and digit extensors: • Innervated by the peroneal nerve • Hock extensors: • Common calcaneal tendon is made up of 5 muscles: 1. Biceps femoris tendon 2. Semitendinous tendon 3. Gracilis tendon 4. Gastrocnemius 5. Superficial digital flexor • Innervated by the tibial nerve • Rupture causes varied degrees of plantigrade stance • Digital flexors: • Innervated by the tibial nerve • The deep digital flexor tendon has no insertion on the calcaneous Hock support structures • Almost entirely a hinge joint • Very strong collateral ligaments • They have long and short portions that are taut at different positions of joint flexion and extension • The plantar tarsal ligaments are similar to carpus: - Several individual ligaments but they function as one large mass - Provides resistance to hyperextension • Can have medial/lateral displacement

Neurovascular supply • Femoral, dorsal pedal and saphenous veins • Sciatic nerve: 1. Gluteals and tensor fascia lata 2. Hamstrings 3. Sensory to the caudal hindleg • Tibial nerve: 4. Gastrocnemius, superficial digital flexor, popliteus and deep digital flexor 5. Interosseous and sensory to the plantar distal limb • Peroneal nerve: 6. Sensory to the lateral limb and peroneus longus 7. Cranial tibial 8. Sensory to the dorsal paw

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Lecture 2

• Femoral nerve: 1. Iliopsoas 2. Quadriceps 3. Satorius • Saphaneous nerve: 4. Cutaneous branch is sensory to the medial limb and digits • Obturator nerve: - Pectinous, adductor and gracilis - All the adductor muscles of the hindleg Cutaneous innervation

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