Canine Osteology- Thoracic Limb Flashcards
Anatomy
Study of form, structure and disposition of tissues and organs that form the body.
What is the function of the skeleton?
Support (posture/gait)
Locomotion (lever)
Protection
Mineral Homeostasis (ca++)
Hemopoiesis
How are bones classified?
Topography/location
Development
Shape
Axial (topography)
Head, vertebral column, sternum, ribs and hyoid apparatus
(on the body)
Appendicular
Limb bones
Splanchnic bones
Bones that develop as soft tissues
Os penis (dog) and Ossa cordis (cattle)
Endochondral development
Bones that start as cartilage and replaced later by bone
(limbs/ vertebrae)
Intramembranous Development
Bones that differentiated directly into fibrous CT (skull/ face)
Long bones
Cylindrical with 3 centers of Ossification (growth plate)
1 Diaphysis (shaft)
2 Epiphysis (one for each extremity)
Metaphysis
Humerus, femur
Short Bones
Carpal, tarsal
Flat bones
Scapula, skull
Irregular bones
Vertebrae
Sesamoid bones
Ossification of cartilage in tendons for extra strength at stress points.
Move tendon away from axis.
Metaphysis
The portion of a long bone between the epiphysis and the diaphysis
Contain the growth places (no active growth plates at a certain age)
CS: Metaphysial fractures
Thoracic Limb (forelimb)
- Pectoral Girdle (shoulder): scapula and clavicle
- Brachium: Humerus
- Antebrachium: radius and ulna
- Forepaw (manus): carpus, metacarpus, phalanges–> proximal, middle distal (order of the digit)
Conditions affecting the forelimb
Fractures
Tumors (osteosarcoma)
Panosteitis
DJD
Hypertrophic Osteodystrophy
Osteosarcoma
Most common malignant tumor in dogs all ages and all breeds
Starts deep within the bone and grow outward
Lameness
Pathologic fractures (doing regular activities, then the bone breaks)
Panosteitis
Inflammatory disease affecting young dogs of large breeds
Endosteal and periosteal new bone formation (legs)
Self limiting disease (heal with or without treatment)
Hypertrophic Osteodystrophy (HOD)
Affects young, rapidly growing large breeds
Produces severe lameness and pain, affects multiple limbs
What are other names for HOD?
Skeletal scurvy, Moller-Barlow’s disease, Osteodystrophy II
Shoulder clinical consideration
Osteosarcoma
But unusual because it’s a well protected muscle
Why are fractures at the distal end of the humerus concerning?
Because radial, medial and muscultaneous nerves could be damaged
Even if not damaged, vet could affect nerves coming in laterally to fix it
Humerus clinical consideration
Fractures: condylar and diaphysis
Osteosarcoma
Forearm clinical significance
Fractures
Osteosarcoma
Panosteitis
HOD
Clinical consideration of the clavicle
It’s small and barely developed
In cats it’s longer
No function
Shown on the radiograph and could be mistaken as a chip fracture
How do you locate the shoulder?
You would use the greater tubercle and the acromiom to palpate the shoulder
What is the difference between the cat and dog acromiom?
The cat has two part to its acromiom: the hamate and the suprahamate
The ______ articulates with ______ to form the shoulder joint
- scapula
- humerus
The ______ and ____ articulates with ______ to form the elbow joint
- radius
- ulna
- humerus
What is the difference between the foramens at the bottom of the humerus for the dog and the cat
Cat: supracondyloid foramen- slit
Dog: supratrochlear foramen- spherical
What is the clinical consideration of the supracondyloid foramen
The median nerve and brachial artery runs through them
Proximally, the ulna is always ________ to the radius
caudal medial
Distally, the ulna is always ______ to the radius
lateral
Clinical Significance of the Olecranon Tuber
Point of the elbow
Located at the 5 intraocular, the heart is located between the 3rd and 5th rib, so when you locate the OT you can find the heart and do heart and lung auscultations
What view can the accessory bone of the manus be seen in?
Palmar view
