2. HOW TO DESCRIBE A BONE?
1. LOCATION OF THE BONE:
2. CLASSIFICATION OF THE BONE :
3. ARTICULATIONS OF THE BONE :
4. DESCRIPTION OF THE BONE :
5. Characteristic/ prominent feature of the bone
6. Orientation/Representation/ Direction of the bone
7. General feature of the bone
8. Comparative features of the bone (ox, horse, dog)
4. Os-coxae
Type of bones: modified flat bones
Located in: hip
Articulate proximally with the Sacrum, creating the ‘Ilio-sacral’ joint
Articulate distally with the head of the Femur, creating the ‘hip’ joint
Articulates medially, creating the pelvic symphysis
Characteristically are made of 3 fused bones
5. General Description - Os-coxae
The largest of the flat bones.
It forms the skeleton of the palvic/ hip region.
It is made up of three fused bones, which join at the cup-shaped cotyloid
cavity ‘Acetabulum’.
6. General Description - Ilium
lies on cranial side of the os-coxae. It is the largest of the three bones.
It has 2 parts: cranial, flattened, extended ‘wings’; and a caudal, constricted
‘body’
It has 2 surfaces: the dorsal ‘gluteal’ and ventral ‘sacro-pelvic’ surfaces.
It has 3 borders: the cranio-dorsal, medial, and ventro-lateral borders.
It has 2 angles: the medial ‘tuber sacrale’ and the lateral ‘tuber coxae’
7. Further Description - Ilium
Gluteal surface - smooth and concave.
A ‘Gluteal’ line extends from the dorsal to the medial border.
Sacro-pelvic surface - convex and rough. Has a rough ‘auricular’ area for
articulation with the sacrum.
An ‘Iliopectineal’ line extends from below the articular surface to the cranial
border of the pubic bone i.e. pectin (rough area)
8. General Description - Ischium
Second largest of the three bones.
Has 4 parts:
• Table
• Tuberosity
• Body
• Ramus
Large oval ‘obturator’ foramen on the border with pubis.
Ischiatic tuberosity on the caudo lateral side.
9. Further Description - Ischium
There is an ‘Ischiatic spine’ above the Acetabulum which separates the
greater and lesser ischiatic notches (depressions).
These notches have grooves for nerves and vessels.
10. Pubis
Is the smallest of the three bones.
Has 2 parts:
• Body
• 2 Remi -cranial and caudal
11. Feature Ox Horse Dog
Os-coxae (ilium)
Dorso-ventral
direction slightly
parallel
Dorso-ventral
direction
Parallel
Tuber coxae
Constricted on edges,
thick in middle
Wide at ends,
constricted in middle
Hook-like, extended
ventrally
Tuber sacrale Below sacrum
Highest point of back,
above sacrum
Straight, found on
lateroventral side
Auricular surface Triangular Irregular
Pelvic symphysis
Tubercle on ventral
surface
ridge
Ischiatic tuberosity 3 parts 2 parts
Extended, curved,
caudo-lateral side
18. Pelvis
The bony pelvis is a broad ring around the pelvic cavity. It gives attachment to a multitude
of muscles, tendons and ligaments and its surfaces are modelled accordingly.
roof is formed by the sacrum and first few caudal vertebrae
floor by the pubic and ischial bones
lateral walls by the ilium and ischium. The broad sacrotuberous ligaments closes the
bony defect in the lateral wall in all domestic mammals, except the carnivores.
The anterior aperture or inlet of the pelvis is bounded by the terminal line or brim, which is
composed of the base of the sacrum dorsally the ilio-pectineal lines laterally, and the pecten
pubis ventrally.
19. Pelvic aperture or inlet (cranial) is bounded by the terminal line, passes along the
promontory of the sacrum dorsally, the wings of the ilia laterally and ends in pectin pubis
ventrally.
Pelvic aperture or outlet (caudal) is formed by the first three or four caudal vertebrae
dorsally, the ischiatic arch and the ischial tuberosities ventrally and the broad sacrotuberous
ligament laterally.
The floor of the pelvis is of considerable obstetric importance.
Pelvic axis: conjugate or sacro-pubic diameter Distance from the sacral promontory to the
cranial border of the pelvic symphysis. It measures the diameter of the pelvic inlet.
Diameter Transvers is measured at the greatest width, i. e., just above the psoas, tubercle.
• Diagonal conjugate diameter: Distance from the sacral promontory to the caudal border of
the pelvic symphysis. Vertical diameter: Diameter between the sacrum or caudal vertebra
and the pelvic symphysis.
20. average conjugate diameter is about 91/2 inches in the mare, 73^ inches (ca. 18.75 cm.) in the stallion.
21. Femur
Type of bone: long bone
Located in: thigh
Articulates proximally with the Acetabulum, creating the hip joint
Articulates distally with the Tibia & Patella, creating the ‘Stifle’ joint
Characteristically has trochanter.
Presented cranio-ventrally
22. General Description - Shaft
Is cylindrical and has 4 surfaces.
Proximally wide.
Caudal side is flattened.
23. General Description - Proximal Epiphysis
Has 2 trochanter (Greater- lateral & lesser- medial).
Has a convex head on the medial side, upon which is a ‘fovea capitis’ which
attaches with a short ligament ( round lig)+(accessory *horse) in the
Acetabulum.
Trochanters are joined by an intertrochanteric crest which form a wall.
depresion created with the lateral wall is called the ‘intertrochanteric fossa’.
24. General Description - Distal Epiphysis
Has trochlea on the cranial surface, and 2 condyles on the caudal surface.
Each condyles has an epicondyle, of which the medial is larger.
b/w the trochlea and condyles is an extensor fossa.
There are two supracondylar tuberosities and a supracondylar fossa.
There is a rough popliteal surface above the condyles as well.
25. Comparison
Feature Ox Horse Dog
Third trochanter Absent Present Absent
Intertrochanteric crest
Connects greater
and lesser
trochanters
Connects greater
and third
trochanters
Connects greater
and lesser
trochanters
Greater trochanter
Large, undivided,
on level with head
Divided cranio-
caudally by a
notch
Undivided, on
level with head
Intertrochanteric fossa
Bound by a caudal
wall
Bound by a lateral
wall
Bound by a caudal
wall
Supracondyloid fossa Shallow Deep Absent
Fabellea absent absent present
29. General Description Pattela
Type of bone: (Largest) sesamoid bone
Located in: stifle joint
Articulates with Femur and Tibia, creating the stifle joint
It has 2 surfaces (dorsal and caudal) and 3 borders (2 bilateral and a dorsal
‘base’)
Has a distal ‘apex’ and is medially pointed.
Oxen have the most pointed patella.
30.
31. Tibia
Type of bone: long bone
Located in: Crus/leg region
Articulates proximally with Femur, creating the stifle joint
Articulates distally with Tarsal bones, creating the hock joint
Characteristically has cochlea
Presented vertically
32. General Description - Shaft
Prismatic in shape.
Has 3 borders: cranial, medial, and lateral.
Has 3 surface:
• caudal - most rough, flat
• medial - convex, rough
• lateral - concave, smooth
Tibial crest at cranial border.
Nutrient foramen.
33. General Description - Proximal Epiphysis
Has 2 condyles - a rounded lateral condyles, and a medial oval-shaped
condyle.
2 intercondyloid eminences - lateral is smaller and slightly caudal, medial is
larger and slightly cranial.
2 intercondyloid areas (fossae cranial and caudal).
Tibial tuberosity on cranial border.
Extensor groove between the lateral condyle and tibial tuberosity.
Popliteal notch on caudal surface, between 2 condyles.
34. General Description - Distal Epiphysis
Called cochlea.
Articulating surfaces divided by an oblique sagittal ridge.
Have two small projecting malleoli, one on either side (lateral and medial).
35. Comparison
Feature Ox Horse Dog
Fibula
Small, doesn’t
extend distally
Ends half way
down the shaft
Extended down
the length of
Tibia
Tibia Single curve Straight Doubly curved
Tibial tuberosity Undivided
Divided by a
groove
Undivided
Ridges of cochlea Straight Oblique Straight
Popliteal lines Less prominent Most prominent Less prominent
36. Fibula
Thin, and sharp.
Lies on lateral side of Tibia.
Proximally wider. Attached to Tibia at a facet.
Distally pointed
40. Tarsal Bones
Type of bones: Short bones
Located in: Tarsal joint or ‘Hock’ joint
Articulate proximally with the Tibia & Fibula, creating the Tibiotarsal joint
Articulate with one another, creating the intertarsal joint
Articulate distally with the metatarsal bones, creating the tarsometatarsal
joint
Characteristically are presented in 2 rows (proximal and distal rows)
41. General Description
Ideally have two rows, with three bones in the proximal row and four bones
in the distal row.
The proximal row consists of:
• Talus bone
• Calcaneus bone
• Central bone
The distal row is numbered, from medial to lateral 1-4
42. Further Description - Proximal Row
Talus Bone - Medial-most, has a trochlea on the proximal end*.
*Oxen have two trochlea; the second one being on the distal end. The
proximal trochlea has ridges, while the distal has condyles.
Calcaneus Bone - Lateral-most, largest, has the ‘Sustentaculum tali’ which is
a medially-projected process, and the ‘Calcaneal tuber’ which is the
dorsally-projected tuberosity.(point of hock)
Central Tarsal Bone - A flattened bone, nestled below the Talus, separating it
from the 1st, 2nd, and 3rd tarsal bones.
43. Further Description - Distal Row
From medial to lateral, they increase in size.
1st is the smallest.
4th is the largest.
44. Comparison
Feature Ox Horse Dog
Number of bones 5 6 7
Proximal row
(Talus) (Calcaneus)
(Central+4)*
(Talus) (Calcaneus)
(Central)
(Talus)
(Calcaneus)
(Central)
Distal row (1) (2+3) (Central+4)* (1+2) (3) (4) (1) (2) (3) (4)
Trochlea(talus) 2: proximal and distal Only one, proximal, trochlea
Groove on
calcaneal tuber
Present Absent
Calcaneus bone Compressed Thicker and wider
52. Metatarsal Bones
Type of bones: Long bones
Located in: Pes
Articulate proximally with the Tarsal bones, creating the ‘Hock’ joint
Articulate distally with the Phalanges, creating the ‘Fetlock’ joint
They are larger, and longer than their forelimb counterparts: the metacarpal
bones
53. Comparison with Metacarpal Bones
Animal Metatarsal Metacarpal
Ox
4 surfaces
Deep vascular groove
2 surfaces
Shallow vascular groove
Horse
More rounded, and
cylindrical
Less rounded, wider
Dog First digit missing
First digit present as a
‘Dew claw’
58. THORACIC SKELETON
Ribs
It form the largest part of the thoracic skeleton. There are usually 13 pairs of ribs in the
dog/ox 18 in horse.
Each rib is divided into a laterally and caudally convex dorsal bony Part and a ventral
cartilaginous part, the costal cartilage.
The first nine ribs articulate with the sternum and are called the sternal or true ribs, the
last four are called the asternal or false ribs. The costal cartilages of the tenth, eleventh, and
twelfth ribs unite with the cartilage of the last sternal rib (the ninth) to form the costal arch
on each side. Because the cartilages of the last (thirteenth) pair of ribs end freely in the
musculature, these ribs are sometimes called floating ribs.
The ninth ribs are the longest, with the longest costal cartilages.
The space between adjacent ribs is known as the intercostal space.
59. A typical rib presents a vertebral extremity, a sternal extremity, and an intermediate
shaft, or body. The body of the rib in general, is cylindrical and slightly enlarged at the
costochondral junction.
The vertebral extremity consists of a head, neck and a tubercle.
The head of the rib has a wedge-shaped articular surface that articulates with adjacent
costal foveae of contiguous vertebral bodies and the intervening fibrocartilage.
In the thoracic region T1-T10 the head of each rib articulates over the intervertebral disc
with the costal fovea formed by the two adjacent vertebrae.
At the eleventh or twelfth thoracic vertebra the caudal pair of costal fovea disappear as the
last two or three ribs articulate only with their corresponding vertebrae.
The tubercle of the rib bears an articular surface for articulation with the transverse
process of the vertebra of the same number.
60. The costal cartilage is the cartilaginous cylindrical distal continuation of the bony rib.
It is smaller in diameter than the bony rib.
The costal groove on the inner surface, for the intercostal vessels and nerve, is not distinct
on any of the ribs.
The first rib articulates with the first sternebra. Succeeding true rib cartilages articulate
with successive intersternebral cartilages. However, the eighth and ninth costal cartilages
articulate with the cartilage between the seventh sternebra and the last sternebra, or xiphoid
process.
The costal cartilages of the tenth, eleventh, and twelfth ribs are long, slender rods with
each joined to the one above to form the costal arch.
The costal cartilage of the thirteenth rib, shorter and more rudimentary than those of the
adjacent ribs.
61.
62. Sternum
The sternum is an unpaired segmental series of eight bones, sternebrae, that form the
ventral boundary of the thorax. The consecutive sternebrae are joined by short blocks of
cartilage, the intersternebral cartilage.
The sternal ends of the ribs articulate with the intersternebral cartilages, with the exception
of the first pair, which articulate with the first sternebra.
The first and last sternebrae are specialized. The cranial half of the first sternebra is
expanded and bears lateral projections for the attachment of the first costal cartilages.
The first sternebra is longer than the others and is known as the manubrium.
The last sternebra, called the xiphoid process is wide and flat and roughly rectangular.
A thin cartilaginous plate, the xiphoid cartilage prolongs the xiphoid process caudally.
