Osteology Fore Limb PDF

OSTEOLOGY ANATOMY-I (ANAT-101) Crd Hr 3(1-2) BY SULTAN ALI DVM (SAU, TANDOJAM) MPHIL (UVAS, LAHORE)  HOW TO DESCRIBE A BONE? 1. LOCATION OF THE BONE: 2. CLASSIFICATION OF THE BONE : 3. ARTICULATIONS OF THE BONE : 4. DESCRIPTIO...

OSTEOLOGY ANATOMY-I (ANAT-101) Crd Hr 3(1-2) BY SULTAN ALI DVM (SAU, TANDOJAM) MPHIL (UVAS, LAHORE)  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. Representation/ direction of the bone 7. General feature of the bone 8. Comparative features of the bone (ox, horse, dog)  Bones of the Forelimb Scapula Humerus Radius and Ulna Carpal Bones Metacarpal Bones Phalanges  Scapula Type of bone: Flat bone Located in: ‘Shoulder’ region Articulates Distally: With Humerus, forming the ‘Shoulder’ joint Characteristic feature: Has the scapular ‘spine’ Presented in the body: Obliquely, in the cranio-ventral direction It has: 2 surfaces, 3 borders, and 3 angles  General Description - Lateral Surface The spine divides the lateral surface of the Scapula into two fossae: The supraspinous and infraspinous fossae. The supraspinous fossa is on the cranial side of the spine, is smooth and relatively small. The infraspinous fossa, located caudal to the spine, is wider and only proximally smooth. Near the neck is the nutrient foramen, and below it there is a vascular groove. Scapula of dog: Lat: view  General Description - Medial Surface On the dorsal end of the medial surface of the scapula there is a rough area for muscular attachment called the ‘Facies Serrata’. Below it -and taking up a majority of the distal surface area- is the subscapular fossa. Scapula of dog: Med: view HORSE  Further Description - The Spine Extends from proximal to distal end of the Scapula. Is thick, rough and partially subcutaneous. Half way down the spine, there is a prominence called the spinal ‘tuber’. On the distal end of the spine is the ‘Acromion process’, absent in some species.  Further Description - Borders Cranial border - Proximally convex and rough. Distally concave and smooth (scapular notch). Caudal border - Proximally and Distally thick, thinning in the middle. Slightly concave. Dorsal border - In younger subjects: thick and pitted. In old subjects: thin, irregular and porous.  Further Description - Angles Cranio-dorsal angle - relatively thin, almost a right angle Caudo-dorsal angle - thick, and rough.  Further Description - Ventral Angle A cup-shaped glenoid cavity is present, which articulates with the head of the Humerus (creating the synovial ‘shoulder’ joint). Sandwiching the glenoid cavity are the supraglenoid* (cranial) and infraglenoid (caudal) tuberosities. Of which the cranial is larger. On the medial side, behind the supraglenoid tuberosity is the ‘coracoid process’. *also called the ‘tuber scapulae’  Feature Ox Horse Dog General Triangular Less triangular Somewhat rounded From dorsal border From below dorsal From dorsal border to Spine to Acromion border, not reaching Acromion process process distal end Acromion Extends ventrally Absent Bends caudally process Lateral fossae 1:3 1:2 1:1 (almost) (supra:infra) Sinuous, no spinal Straight, spinal Mostly straight, no Spine tuber tuber tuber Nutrient Below spine Caudal border foramen Coracoid Rounded, not Elongated, Rounded,rudimentary process prominent prominent projection  Humerus Type of bone: Long bone Located in: Brachium Articulates proximally with scapular glenoid cavity, creating shoulder joint Articulates distally with condyle of Radius & Ulna, creating elbow joint Characteristically has the ‘Deltoid’ tuberosity Presented: Obliquely, in the caudo-ventral direction It has 4 surfaces  General Description - Shaft It has a twisted, sigmoid (S) shape. The lateral surface is smooth and spirally curved, forming the musculo-spiral, ‘brachialis’ groove. The medial surface is straight, blending with the cranial and caudal surfaces. Half way down the medial surface is the ‘Teres Major’ tuberosity. Opposite to which, on the lateral surface is the ‘Deltoid’ tuberosity. Above the Deltoid tuberosity is the smaller ‘Teres Minor’ tuberosity.  General Description - Proximal Epiphysis Has 2 tuberosities (Major, lateral & Minor, medial ‘tubercles’), separated by an ‘intertubercular/ bicipital groove’. Caudal to these is the Humeral ‘head,’ which is twice the size of the Scapular glenoid cavity. Below the head is the Humeral ‘neck’. Lat: aspect humerus Horse  General Description - Distal Epiphysis Has 2 condyles (Lateral ‘Capitulum’ & medial ‘Trochlea’). Has 2 fossae (Cranial ‘Radial’ & caudal ‘Olecranon’ fossae). Has 2 epicondyles. Lateral and medial Has (in dogs) a supratrochlear foramen. Above the lateral condyle is the supracondyloid crest.  Feature Ox Horse Dog Summit of Major Significantly higher Significantly higher Just above level of head tubercle than head than head Rounded, similar in size Small, rounded, blunt, Lesser tubercle Pointed, small to greater tuberosity and rough Intertubercular Two, separated by Only one Only one groove intertubercular ridge Deltoid tuberosity Slightly pronounced Most developed Least pronounced Teres major Pronounced Slightly developed Only a flat, rough area Brachialis groove Shallow Deep Shallow, most twisted Connected by Radial & Deep, wide Shallower than Ox supratrochlear Olecranon Fossae foramen Epicondyles Extends on Caudal side Extends on Caudal side Bilateral  Radius & Ulna Type of bones: Long bones Located in: Antebrachium Articulate proximally with Humerus, creating the elbow joint Articulate distally with Carpal bones, creating the ‘Knee’ joint Characteristically are fused Presented: Vertically  General Radial Description - Shaft Has 2 surfaces and 2 borders. Cranial surface is smooth and convex, while the caudal is rough and concave. The medial border is slightly concave and mostly subcutaneous. The lateral border is more concave but has no special features. Ulna is attached to the caudal surface caudo- laterally*.  General Radial Description - Proximal Epiphysis Has 2 articulating glenoid cavities. The medial being the larger one. There is a prominent lip on the cranial side of the articulating surface called the ‘Coronoid’ process. Below which is the cranio-medially located radial tuberosity/ ‘Bicipital tuberosity’. On either side of the epiphysis are radial tuberosities (smaller, medial & larger, lateral).  General Radial Description - Distal Epiphysis Consists of 3 facets (for articulation with the proximal carpal bones); Largest of which is the medial facet, articulating with the Radial Carpal bone. Second to which is the middle facet, which articulates with the Intermediate Carpal bone. The lateral facet is smallest, and articulates with both the Ulna and Accessory Carpal bones. On the cranial side of this distal epiphysis are 3: lateral, middle, and (the oblique) medial, extensor grooves through which extensor tendons passes. Furthermore there are 2 distal bilateral radial tuberosities.  Comparison Feature Ox Horse Dog Proximal Sagittal groove Sagittal ridge Undivided epiphysis Radial /Bicipital Slightly rough Well developed Faint/absent tuberosity area Well attached Attached with Separate from completely with Radius,ossified to Ulna Radius* Radius and medial side and Extended distaly extended distaly does not extended distaly Oblique Straight No distinct Distal epiphysis articulating articulating articulating surfaces surfaces surface Shape distaly Prismatic Flat borders Flat, wide distally  General Ulnar Description - Shaft Prismatic in shape proximally, having 3 surfaces: medial, lateral, and cranial (attached with Radius) Distal end is a knob like projection called styloid process.  General Ulnar Description - Proximal Epiphysis Has the dorsally presented ‘Olecranon tuber’. Below which there is the hook-like ‘Anconeal process’. This creates the vertically present concavity, the ‘trochlear notch*’/ semilunar notch. Below this, there is a horizontal concavity, which is the ‘radial notch’. The bilateral ends of the radial notch are called the ‘Coronoid processes’of ulna (of which the medial is larger).  General Ulnar Description - Distal Epiphysis Ends in a pointed ‘Styloid’ process.  Comparison Feature Ox Horse Dog Extends Fuses with Degree of towards distal radius half way Separate fusion end of bone down the bone Interosseous 2: Proximal Only one, Separate space and distal proximal bones Pointed, at Fused with Styloid process Knob-like lateral side radius Radius and ulna of dog Cr:&Cd: view OX OX Carpal Bones  Carpal Bones Type of bones: Short bones Located in: Carpal Joint or ‘Knee’ joint Articulate proximally with the Radius & Ulna, creating the radiocarpal joint Articulate with one another, creating the intercarpal joint Articulate distally with the metacarpal bones, creating the carpometacarpal joint Characteristically are presented in 2 rows (Proximal and distal rows)  General Description Ideally have two rows, with 4 bones in each row. The proximal row consists of: Radial Carpal Bone (RC) Intermediate Carpal Bone (IC) Ulnar Carpal Bone (UC) Accessory Carpal Bone (AC) The distal row is numbered, from medial to lateral as: 1st, 2nd, 3rd and 4th.  Further Description - Proximal Row Radial Carpal Bone - Medial-most, largest, saddle shaped. Intermediate Carpal Bone - Smaller than RC, wedge shaped. Ulnar Carpal Bone - Smaller than IC, irregularly shaped. Accessory Carpal Bone - Palmar to UC, may be rounded or disc shaped.  Further Description - Distal Row From medial to lateral, they increase in size. 1st is the smallest. 4th is the largest, and has a tetrahedral shape (in dogs)  Comparison Feature Ox Horse Dog Number of 6 7 7 bones Proximal row (1) (2) (3) (4) (1) (2) (3) (4) (1+2) (3) (4) (1)* (2) (3) Distal row (X) (2+3) (4) (X) (2) (3) (4) (4) Carpus region of dog  Metacarpal Bones Type of bones: Long bones Located in: Manus Articulate proximally with Carpal bones, creating the ‘Knee’ joint Articulate distally with the Phalanges, creating the ‘Fetlock’ joint Characteristically vary greatly from species to species  General Description The proximal epiphysis is called the ‘base’ of the bone, and the distal epiphysis is called the ‘head’. On the base, there are 2 articulating cavities, divided by a sagittal ridge; lateral & medial articulating facets, as well as a dorsal metacarpal tuberosity. The shaft sometimes exhibits vascular grooves. The head has fossae on caudal side for attachment of sesamoid bones, and 2 condyles separated by a crest/ridge(metacarpal trochlea). Dorsal & palmar view  Comparison Feature Ox Horse Dog 3 bones: 1st missing, 2th and 5 bones: 1st has 2 bones: 1st 4th short only 2 Number of and 2nd metacarpal phalanges, 2nd metacarpal missing, 3rd+4th ‘splint’ bones, and 5th are bones fused, and a 5th and the 3rd similar in size, vestigial bone large 3rd and 4th are metacarpal longest ‘cannon’ bone  2 on dorsal 4 on distal end, surface of palmar surface; Number and proximal end; 5 on dorsal And one in location of And 1 surface; 9 on each of the sesamoid ‘Navicular’ palmar surface functional bones bone on distal Total: 14 digits end Total: 6 Total: 3 Distal end Synovial notch Sagittal crest Sagittal crest  Phalanges Located in: Manus Articulate proximally with the metacarpal bones, creating the ‘fetlock’ joint Articulate distally with second and third phalanges, creating the ‘pastern’ and ‘coffin’ joints Presented: at the distal-most end of the limbs.  General Description - Long Pastern Bone Proximal base has 2 articulating glenoid cavities, which are divided by a deep sagittal groove. Distal head has 2 articulating condyles, divided by a faint sagittal groove. Flattened bone. General Description - Short Pastern Bone Base has two glenoid cavities, divided by a ridge. Width of bone is twice its length. Head has two condyles divided by a groove. Specific Description - Coffin Bone of Horse Has 3 surfaces (anterior, posterior, and solar) and 3 borders (carnual, solar, and posterior). Anterior surface is porous, rough, and has several foramina. Solar surface has 2 parts and is crescent shaped. Its anterior part is smooth, its posterior part is rough and has 2 solar foramina. Posterior surface has 2 cavities. Sloped proximo- distally and anterio-posteriorly. The Carnuval border has an extensor process. Specific Description - Coffin Bone of Horse CON’T The solar border is sharp, notched and rounded (pointed in oxen). The posterior border hosts the large sesamoid ‘navicular’ bone. It also has 2 wings (with a foramen in each), the medial being large.