Osteology Flashcards
Function of Skeleton
Support (posture/gait)
Locomotion (lever)
Protection
Mineral homeostasis (ca+,phosphorus)
Heamopoiesis
Classification of Bones
1/ Topography/Location
2/ Development
3/ Shape
Topographical
a) Axial:
Head, Vertebral Column, Sternum, Ribs and Hyoid apparatus
b) Appendicular:
limbs bones
c) Splanchnic bones
(Os penis (dog) , Ossa cordis ( cattle)
Developmental
a) Endochondral
b) Intramembranous
Endochondral
Bones that start as cartilage & replaced later by bone (Limbs/ Vertebrae)
Intramembranous
Bones that differentiated directly into fibrous connective tissue (skull/ face)
shape : Individual bones, classified according to shape into
long bones (humerus, femur)
Short bones (carpal, tarsal)
Flat bones (scapula, skull, pelvic)
Irregular bones (vertebrae)
Sesamoid bones (patella)
Sesamoid bones significance
Are used to create a barrier for the tendons to be away from high moving joints
Developed within tendons of insertion
a) Change tendons insertion direction away from the moving bones edges
b) Increase leverage exerted by muscles
Components of the long bone
Cylindrical has 3 Centers of Ossification (Growth Plate)
One for the shaft (Diaphysis)
Two Epiphysis (one for each extremity)
Metaphysis:The portion of a long bone between the epiphysis and the diaphysis. It contains the growth plate
Thoracic limb components
- Pectoral Girdle (Shoulder):
- Scapula
- Clavicle - Brachium:
- Humerus - Antebrachium:
- Radius
- Ulna - Forepaw (manus)
- Carpus
- Metacarpus
- Phalanges
( proximal, middle, distal= a digit)
Significance of clavicle in dogs
The clavicle in dogs are reduced compared to humans
Small oval plate, cranial to the shoulder within the clavicular tendon
-tiny cartilaginous plate within the brachiocephalic tendon
Be careful not to mistaken it as a fracture (chip fracture) because it is the clavicle
Scapula
Flat bone consist of
Two surfaces(lateral & medial),
Three borders(dorsal, cranial & caudal)
Spine , acromion, supraspinous fossa & infraspinous fossa
palpable structures:
- borders
- spine
- acromion
- supraglenoid tubercle
The muscles on the medial side of the scapula
Serrated face
(Serratus ventralis M)
Subscapular fossa
(Subscapularis M)
The Glenoid Cavity
Shallow cavity that receives the head of the humerus (shoulder joint)
Note the Supraglenoid tubercle, coracoid process and infraglenoid tubercle
The Feline Scapula
Acromion is broadened by a flat, caudally directed “Suprahamate” process & distally directed ‘hamate’ process
Important landmarks of the shoulder
The acromion and greater tubercle and head of humerus are important to access/find the shoulder joint to insert fluids/medications etc
Palpables Structures of the shoulder
Easily Recognizable
1. Acromion, hammate & superhammate
2. Great Tubercle
Deep Palpation:
3. Scapular spine
The Brachium
Brachium: Humerus
The long bone that forms the arm
Articulates with the scapula to form the shoulder joint, and with the radius & ulna to form the elbow joint
The proximal extremity, the body and the distal extremity
The Proximal extremity of the brachium
The proximal extremity consists of the head, neck, greater and lesser tubercles and the intertubercular groove
The distal extremity of the Brachium consists of
The distal extremity (Condyle)
Medial Trochlea (ulna)
lateral Capitulum (radius)
Olecranon fossa (receives the anconeal process of the ulna) / Supratrochlear Foramen (dog)
Epicondyls (lateral & medial)
Supracondylar foramen (Cats)
Where the median nerve & brachial artery pass through
Important to be mindful when doing surgery
Antebrachium
Radius & Ulna
In the upper part of the forearm, the ulna located caudo-medial to the radius
In the lower part, the ulna located laterally
Radius
Articulates proximally with the humerus and distally with the carpus
Articulates with ulna proximally by its caudal surface, and distally by its lateral border
The proximal extremity consists of head (with fovea capitis & radial tuberosity)
The distal extremity of the Radius consist of
The distal extremity
Trochlea
1. Ulnar notch (laterally)
2. Styloid process (medially)
Ulna
Olecranon (point of elbow)
AT the 5th intercostal
Olecranon tuber
Anconeal process
Trochlear notch
coronoid process
Distal extremity (the head with styloid process)
Manus (forepaw)
Consists of :
Two rows of Carpal Bones
One raw of Metacarpal Bones
Three rows of Phalanges (Phalanx)
Metacarpal bones
Contains 5 bones numbered (I-V),from medial to lateral
The first forms the dewclaw
The Phalanges
Arranged in 3 rows proximal, middle and distal for each of the four main metacarpals
Note: The first digit has only two phalanges, proximal & distal
Clinical Consideration:
Conditions affecting the forelimb
- Fractures
2. Tumors (Osteosarcoma)
3. Panosteitis
4. DJD ( Degenerative Joint Diseases)
5. Hypertrophic Osteodystrophy (HOD)
Osteosarcoma
Most common malignant tumor in dogs
all ages & all breeds are affected (large breeds)
Starts deep within the bone & grow outward (bone destroyed)
lameness
Pathologic fractures
Panosteitis
Idiopathic inflammatory disease primarily affecting young dogs of large breeds
Characterized by inflammation , endosteal & periosteal new bone formation, especially those of the legs.
Lameness of one or more legs is often apparent
Considered a self-limiting disease
Hypertrophic osteodystrophy (HOD)
Bone disease affects young, rapidly growing large breeds
Names (Skeletal Scurvy, Moller-Barlow’s disease, Osteodystrophy II)
The disease produces severe lameness and pain and usually affects multiple limbs
Clinical Consideration:
Shoulder
Fractured shoulder (unusual)
Osteosarcoma
CLINICAL CONSIDERATION
: Humerus
Humerus
1/ Fracture:
- Condylar
- Diaphysis
On the distal third
radial nerve damage/Median & musculocutaneous N (Approach)
2/ Osteosarcoma
Clinical Consideration:
Forearm
Fractures
- fractures at the distal part usually involves both bones
Osteosarcoma
Panosteitis, HOD
Clinical Consideration:
Manus
Manus
Fractures
Tumors:
Osteosarcoma
