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🦴 CLAVICLE - "The Beauty Bone / Collar Bone"

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1. BASIC INTRODUCTION

• Latin name: Clavicula = "small key" (rotates like a key)
• Only horizontal long bone in the body
• Connects sternum (medially) to acromion of scapula (laterally)
• Subcutaneous = felt under skin throughout its length

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2. SHAPE - Easy to Remember

"Medial = Round, Lateral = Flat"

• Shaft = Lateral 1/3 + Medial 2/3
• Weakest point = junction between the two curves (most common fracture site)

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3. TWO ENDS

• Large, quadrilateral
• Articulates with manubrium sterni → forms Sternoclavicular joint
• Also touches 1st costal cartilage

• Flat
• Articulates with acromion → forms Acromioclavicular joint

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4. MUSCLE ATTACHMENTS - Mnemonic

"2 muscles on top, 3 on bottom" (superior vs inferior surface)

Superior Surface:

Inferior Surface:

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5. IMPORTANT LANDMARKS (Inferior Surface)

• Subclavian groove = for subclavius muscle
• Conoid tubercle = for conoid ligament (part of coracoclavicular)
• Trapezoid ridge = for trapezoid ligament
• Impression for costoclavicular ligament = at medial end

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6. PECULIARITIES - Top Viva Points! ⭐

Mnemonic: "SOLO-HMM"

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7. OSSIFICATION ⭐ (High Yield Viva)

• First bone in body to ossify (5th-6th week of intrauterine life)
• 2 primary centres in shaft → fuse by 45th day
• 1 secondary centre for medial (sternal) end → appears at 15-17 years, fuses at 21-22 years
• Ossifies in membrane (not cartilage) - exception among long bones

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8. CLINICAL ANATOMY ⭐⭐

• Most common fracture site: Junction of lateral 1/3 and medial 2/3 (weakest point)
• Cause: Fall on outstretched hand (indirect violence)
• Displacement after fracture:
  • Medial fragment → pulled up by SCM
  • Lateral fragment → pulled down by weight of limb (trapezius alone can't support it)
• Cleidocranial dysostosis: Congenital absence/hypoplasia of clavicle → shoulders can be brought together in front of chest
• Subclavian vessels + brachial plexus pass between inferior surface of clavicle and 1st rib → protected by subclavius muscle (acts as cushion)

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9. SIDE DETERMINATION (To Identify Right/Left)

1. Flat end → Lateral (acromial)
2. Concave surface of lateral end faces forward
3. Subclavian groove → inferior surface, lateral half
4. Conoid tubercle projects downward near acromial end

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QUICK VIVA FIRE ROUND ⚡

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Memory tip for shape: Think of clavicle like the letter "f" lying flat - the medial part is long and rounded, the lateral part is short and flat.

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🦴 RADIUS - "The Rotating Forearm Bone"

Memory trick: "R for Radius = Rotates = Right side of forearm (when palm faces forward)"

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1. BASIC INTRODUCTION

• Lateral bone of forearm
• Homologous with tibia of lower limb
• Upper end = small/rounded (head)
• Lower end = wide/broad (with styloid process)
• Has: 1 upper end + 1 shaft + 1 lower end

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2. SIDE DETERMINATION (How to identify Right/Left)

Remember: "Head up, Broad down, Styloid lateral"

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3. UPPER END (3 parts)

a) HEAD

• Disc-shaped, covered with hyaline cartilage
• Superior concave surface → articulates with capitulum of humerus (elbow joint)
• Circumference → fits into radial notch of ulna + annular ligament → forms Superior Radioulnar Joint

b) NECK

• Enclosed by narrow lower margin of annular ligament
• Head + Neck = FREE from capsular attachment (can rotate freely)

c) RADIAL TUBEROSITY

• Just below medial part of neck
• Rough posterior part = insertion of Biceps Brachii
• Smooth anterior part = covered by bursa

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4. SHAFT - 3 Borders + 3 Surfaces

Borders:

Surfaces:

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5. LOWER END - Most Important! ⭐

• Widest part of bone, has 5 surfaces
• Styloid process = lateral surface prolonged downward (Greek = pillar)

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6. MUSCLE ATTACHMENTS ⭐

Insertion INTO Radius (muscles that insert):

Origin FROM Radius (muscles that arise):

Mnemonic for insertions: "Be Super Pro Pro Bra" Biceps, Supinator, Pronator teres, Pronator quadratus, Brachioradialis

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7. SIX GROOVES UNDER EXTENSOR RETINACULUM ⭐⭐

Mnemonic: "2 Thumbs, 2 Carpi, 1 Digitorum, 1 Indicis" = 1 to 6

Groove 1-4 on Radius, Groove 5 at junction of Radius & Ulna, Groove 6 on Ulna Dorsal tubercle of Lister lies between groove 2 and 3

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8. OSSIFICATION ⭐ (Viva Favourite)

Key point: Lower end is the growing end (appears 1st year, fuses last at 20) Upper end fuses earlier (18 years)

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9. CLINICAL ANATOMY ⭐⭐ (Top Viva!)

A. Colles' Fracture

• Most common fracture = 2 cm above lower end
• Cause: Fall on outstretched hand (FOOSH)
• Distal fragment displaced backward + upward
• Deformity = "Dinner Fork deformity"
• Radial styloid comes to lie proximal to ulnar styloid (normally distal)

B. Smith's Fracture

• Reverse of Colles' = distal fragment displaced forward
• Cause: Fall on back of hand
• Called "Reversed Colles'"

C. Pulled Elbow (Subluxation of Radial Head)

• Sudden jerk on child's hand → head of radius pulled out of annular ligament
• Also called "Nursemaid's Elbow"
• Head felt in hollow behind lateral epicondyle

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10. QUICK VIVA FIRE ROUND ⚡

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BONUS - Radius vs Ulna at a Glance

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Final memory trick: Radius = "R"adius = "R"otates - it rotates around ulna to produce pronation/supination. Ulna is the fixed, stable bone; Radius is the mobile, rotating one!

🦴 RADIUS vs TIBIA - Homologous Bone Comparison

Why homologous? Both are the medial/larger weight-bearing bones of their respective limbs... wait - actually both Radius and Tibia are the bones that articulate with the more important joint distally and are lateral in anatomical position in their respective limbs.

Simple way to remember: Radius is to the upper limb what Tibia is to the lower limb.

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1. BASIC POSITION COMPARISON

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2. GENERAL STRUCTURE COMPARISON

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3. ENDS - DETAILED COMPARISON

UPPER END

LOWER END

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4. SHAFT COMPARISON

Key contrast: Radius - nutrient foramen opens UP. Tibia - nutrient foramen opens DOWN (away from knee, toward ankle). Mnemonic: "To the Elbow I Flee" - radius opens toward Elbow. Tibia opens away from knee (downward).

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5. MUSCLE ATTACHMENTS COMPARISON

Insertions INTO the bone:

Origins FROM the bone:

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6. JOINTS FORMED - COMPARISON

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7. OSSIFICATION COMPARISON ⭐⭐

KEY VIVA POINT:

• Radius growing end = LOWER (wrist end)
• Tibia growing end = UPPER (knee end)
• Mnemonic: "Radius grows Away from elbow, Tibia grows Toward knee" = both grow away from elbow, toward knee
• This is the rule: "Grow away from elbow, grow toward knee"

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8. CLINICAL COMPARISON ⭐⭐

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9. INTEROSSEOUS MEMBRANE COMPARISON

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10. QUICK VIVA FIRE ROUND ⚡

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SUMMARY TABLE - ONE GLANCE REVISION

Dorsal Tubercle of Lister - Acts as Pulley for:

✅ Extensor Pollicis Longus (EPL)

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How to Remember This:

"Lister's tubercle = THUMB's pulley" EPL = Extensor Pollicis (Pollicis = Thumb in Latin) Longus

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Why it acts as a pulley:

• The tendon of EPL winds around the medial side of Lister's tubercle
• Then changes direction - goes obliquely across the wrist toward the thumb
• The tubercle acts like a pulley/fulcrum - changes the direction of pull of EPL
• This allows EPL to retropulse (extend + adduct) the thumb - called "hitchhiker's movement"

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Location of Lister's Tubercle:

• On the posterior surface of lower end of radius
• Lies between 2nd groove (ECRL + ECRB) and 3rd groove (EPL)
• EPL passes in 3rd groove, medial to Lister's tubercle

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Clinical Importance ⭐

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Groove Number Summary (around Lister's):

Mnemonic: "Lister's = L = Longus Pollicis Extensor uses it"

🦴 ULNA - "The Stable Forearm Bone"

Memory trick: "ULNA = Large Near Arm (top)" - large upper end, small lower end

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1. BASIC INTRODUCTION

• Medial bone of forearm
• Homologous with Fibula of lower limb
• Upper end = Large (olecranon + coronoid)
• Lower end = Small (head + styloid)
• It is the FIXED bone - radius rotates around it
• Directly continuous with elbow joint (major contribution)

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2. SIDE DETERMINATION

"Olecranon up + back, Coronoid forward, Styloid medial at bottom"

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3. UPPER END ⭐ - Most Complex Part

Key Processes:

Trochlear Notch:

• Also called semilunar notch
• Formed by olecranon (upper part) + coronoid (lower part)
• Has a smooth ridge dividing it into medial and lateral parts
• Articulates with trochlea of humerus = Elbow joint (Humeroulnar joint)

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4. SHAFT - 3 Borders + 3 Surfaces

Borders:

Surfaces:

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5. LOWER END

• Small, rounded = Head of Ulna
• Head articulates with:
  • Ulnar notch of radius → Inferior Radioulnar Joint
  • Articular disc (triangular fibrocartilage) separates ulna from wrist joint
• Styloid process = posteromedial projection from head
• Ulna does NOT directly articulate with wrist bones (separated by articular disc)

Viva key: Ulna has NO direct contact with carpal bones - articular disc intervenes!

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6. MUSCLE ATTACHMENTS ⭐⭐

INSERTIONS into Ulna:

Mnemonic for olecranon: "TAP" = Triceps, Anconeus inserts into olecranon Posteriorly

ORIGINS from Ulna:

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7. IMPORTANT LIGAMENT ATTACHMENTS

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8. CARRYING ANGLE - Viva Point ⭐

• When elbow is extended + forearm supinated → forearm deviates laterally = Carrying Angle
• Normal = 163-170° (i.e., ~10-15° valgus)
• More in females than males
• Due to obliquity of trochlea of humerus
• Cubitus valgus = increased carrying angle
• Cubitus varus = decreased carrying angle ("gun stock deformity")

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9. OSSIFICATION ⭐

Key: Olecranon ossification centre appears at 10 years Growing end of Ulna = LOWER end (same as radius) Exception: Olecranon fuses early (16 years)

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10. CLINICAL ANATOMY ⭐⭐

A. Olecranon Fracture

• Direct blow to elbow
• Triceps pulls proximal fragment upward
• Gap felt at back of elbow

B. Coronoid Process Fracture

• Associated with posterior dislocation of elbow
• Brachialis avulses the coronoid

C. Monteggia Fracture ⭐⭐⭐

• Fracture of upper 1/3 of ulna shaft + dislocation of radial head
• Mnemonic: "MontEggia = uppEr ulna"
• Opposite = Galeazzi fracture (lower 1/3 radius + distal radioulnar dislocation)

D. Cubitus Valgus

• Increased carrying angle (>15°)
• Causes tardy ulnar nerve palsy (ulnar nerve stretched around medial epicondyle)
• Results in claw hand (ring + little finger)

E. Ulnar Nerve at Elbow

• Passes behind medial epicondyle in cubital tunnel
• Vulnerable to injury here
• "Funny bone" sensation

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11. RADIUS vs ULNA - Quick Contrast

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12. QUICK VIVA FIRE ROUND ⚡

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Final memory trick:

• Ulna = Upper end large = Used for elbow joint mainly
• Radius = Lower end large = used for Wrist joint mainly
• They work as a TEAM: Ulna handles elbow, Radius handles wrist!

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🦴 ULNA - Rapid Revision Card

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IDENTITY

• Medial bone of forearm
• Homologous = Fibula
• Large top, Small bottom (opposite of radius)
• Role = FIXED/STABLE (radius rotates around it)

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UPPER END - "The Wrench/Spanner Shape"

        OLECRANON (back)
             |
     [TROCHLEAR NOTCH] → articulates with Trochlea of Humerus
             |
        CORONOID (front)
        |
   RADIAL NOTCH (lateral) → Superior Radioulnar Joint
        |
   ULNAR TUBEROSITY → Brachialis inserts

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LOWER END

• Head (small) → Inferior Radioulnar Joint
• Styloid process → posteromedial
• ⭐ NO direct wrist articulation → Articular disc (TFCC) intervenes

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SHAFT BORDERS (3)

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KEY MUSCLE ATTACHMENTS

Inserts INTO ulna:

Originates FROM ulna:

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OSSIFICATION

Growing end = Lower end

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CLINICAL ⭐⭐⭐

Mnemonic: "MontEggia = uppEr ulna", "GalEazzi = lowEr radius"

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VIVA BULLETS ⚡

• Ulna = does NOT form wrist joint
• Trochlear notch = semilunar notch (another name)
• Subcutaneous border = posterior border
• Sharpest border = lateral (interosseous)
• Annular ligament attached to = anterior + posterior margins of radial notch
• Oblique cord = from lateral side below radial notch → to radius
• Carrying angle = ~10-15° valgus, more in females

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One-line memory: Ulna = "U-shaped top grips humerus, tiny bottom stays out of wrist" 🔧Here is the complete, updated, textbook-accurate (BD Chaurasia) point-wise breakdown of Ulna from your images:

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🦴 ULNA - Complete Notes (BD Chaurasia)

Memory: "ULNA = Upper Large, Narrower At bottom"

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1. BASIC INTRODUCTION

• Medial bone of forearm
• Homologous with Fibula of lower limb
• Upper end = Large (2 processes + 2 notches)
• Lower end = Small/narrow/rounded
• Stabilising bone of forearm - radius rotates around it

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2. SIDE DETERMINATION

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3. UPPER END - "The Hook" ⭐⭐

Four Key Structures:

        ┌──── OLECRANON (projects upward/backward)
        │          ↓
   [TROCHLEAR NOTCH] = Semilunar notch
        │          ↑
        └──── CORONOID (projects forward)
                   |
           RADIAL NOTCH (lateral surface of coronoid)

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A. OLECRANON PROCESS

• Projects upward from shaft
• Has 5 surfaces: superior, anterior, posterior, medial, lateral
• Anterior surface = articular = upper part of trochlear notch
• Posterior surface = triangular subcutaneous area (separated from skin by bursa) → forms point of elbow
• Superior surface (posterior part) = roughened area = Triceps Brachii inserts
• Anterior part of superior surface covered by bursa

B. CORONOID PROCESS

• Greek = "crow's beak"
• Projects forwards just below olecranon
• Has 4 surfaces: superior, anterior, medial, lateral
• Superior surface = lower part of trochlear notch
• Anterior surface = triangular, rough; lower corner = ulnar tuberosity (Brachialis inserts)
• Lateral surface = upper part has radial notch; lower part has depressed area for radial tuberosity; limited posteriorly by supinator crest
• Medial surface = continuous with medial surface of shaft

C. TROCHLEAR NOTCH (Semilunar Notch)

• Formed by olecranon (upper) + coronoid (lower)
• Articulates with trochlea of humerus → Elbow joint

D. RADIAL NOTCH

• On lateral surface of coronoid
• Articulates with head of radius → Superior Radioulnar Joint
• Annular ligament attached to anterior + posterior margins

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4. SHAFT - 3 Borders + 3 Surfaces

BORDERS:

SURFACES:

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5. LOWER END

• Made of Head + Styloid Process
• Head = articulates with ulnar notch of radius → Inferior Radioulnar Joint
• Ulnar artery + nerve lie on anterior aspect of head
• Styloid process = projects downward from posteromedial side of lower end
• Between head and styloid = groove for Extensor Carpi Ulnaris tendon
• Articular disc separates ulna from wrist joint → Ulna does NOT directly articulate with carpal bones ⭐

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6. COMPLETE MUSCLE ATTACHMENTS ⭐⭐

INSERTIONS INTO Ulna:

ORIGINS FROM Ulna:

LIGAMENT ATTACHMENTS:

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7. OSSIFICATION ⭐⭐

Growing end = LOWER END (appears 5th year, fuses 18th year) Olecranon fuses EARLY at 16 years

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8. CLINICAL ANATOMY ⭐⭐⭐

A. Stabilising Role

• Trochlear notch grips lower end of humerus
• Foundation on which radius can pronate/supinate

B. Elbow Dislocation

• Fall on outstretched hand with elbow slightly flexed
• Olecranon shifts posteriorly
• Elbow fixed in slight flexion
• Bony landmarks disturbed:
  • Normal extended elbow → olecranon tip in horizontal line with two epicondyles
  • Normal flexed elbow → three bony points form equilateral triangle
  • Both relations disturbed in dislocation

C. Olecranon Fracture

• Fall on point of elbow
• Common fracture
• Triceps pulls fragment proximally

D. Coronoid Fracture

• Uncommon
• Usually accompanies elbow dislocation

E. Monteggia Fracture ⭐⭐⭐

• Fracture of upper 1/3 of ulna shaft + dislocation of radial head
• Mnemonic: "MontEggia = uppEr ulna"

F. Madelung's Deformity ⭐

• Dorsal subluxation of lower end of ulna
• Due to retarded growth of lower end of radius
• Ulna appears prominent at back of wrist

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9. THREE BONY POINTS OF ELBOW ⭐ (Viva Favourite)

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10. QUICK VIVA FIRE ROUND ⚡

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Final memory trick for Upper End: "Old Crow Tracks Rabbits" Olecranon + Coronoid + Trochlear notch + Radial notch = 4 key features of upper end of ulna!