RADIUS BONE
&
BONES OF HAND
LEARNING OBJECTIVES
Students should able to
•
Recognize the bones of forearm &hand
•
Determine side of bones.
•
Identify the features of bones.
•
Identify the muscles attached to bones.
•
Identify clinical significance of bones.
RADIUS BONE
•
Lateral bone of forearm
•
Three Parts
•
Upper end

Head

Neck

Tuberosity
•
Shaft
•
Lower end
DETERMINATION OF SIDE
•
Upper end rounded & bears the head.
•
Lower end more wider than the upper end
•
Lateral surface of shaft is convex & its anterior surface is concave
in lower part
•
Styloid process projects from lateral surface of the lower end
HEAD
Disc-shaped, overhangs the neck on all sides
•
Medially it articulates with radial notch of ulna.
•
Upper surface articulates with capitulum-- form elbow joint
•
It is covered with hyaline cartilage.
•
Medial surface articulates with radial notch of ulna to form superior radio-ulnar joint
.
HEAD
Attachment
 Annular ligament to the articular cicumference of head
NECK
•
Constricted part below head
•
Surrounded by lower part of annular ligament
•
Attachments:
Supinator is inserted into the lateral
anterior &posterior aspects of neck
TUBEROSITY
Lies below the medial part of the neck.
•
Attachments:
•
Biceps brachii is inserted into rough posterior part.
•
Smooth anterior part is related to bursa.
SHAFT
•
Narrow above, broader below
•
Three borders.
•
Interosseous(medial)
•
Anterior
•
Posterior
Three surfaces
•
•
Anterior
•
Posterior
•
Lateral
BORDERS
INTEROSSEOUS (MEDIAL) BORDER
•
Sharp except at its upper part
•
Begins from posterio-inferior part of radial tuberosity
•
Lower end form posterior boundary of small triangular
area above ulnar notch of radius
Attachment on interosseous border
•
Pronator quadratus is inserted
•
Gives attachment to interosseous membrane in lower 3\4
ANTERIOR BORDER
•
Begins just below antero-lateral part of radial
tuberosity
•
Upper & lower parts are sharp
Attachments on anterior border
•
Origin of Flexor digitorum superficialis from upper &
lower parts
•
Extensor retinaculum is attached to lower edge
POSTERIOR BORDER
•
Begins from posterio-inferior part of tuberosity
•
End in dorsal tubercle at back of lower end
•
Prominent in middle part
SURFACES
ANTERIOR SURFACE
•
Lies between anterior and interosseous
border
•
Presents nutrient foramen directed up ward
Attachments on anterior surface
•
Origin to flexor pollicis longus from upper 2\3
•
Insertion to pronator quadratus in lower 1\4
POSTERIOR SURFACE
•
•
•
Lies between interosseous & posterior borders
Origin of Abductor pollicis
longus from upper part
Origin of Extensor pollicis brevis from lower part
.
LATERAL SURFACE
•
Lies between anterior&posterior borders
•
Rough ridge in middle part gives insertion to
pronator teres
•
Insertion to supinator into V Shape area at upper
part
•
Brachioradialis is inserted just above styloid
process
LOWER END
•
Expanded &rectangular
•
Has five surfaces
•
Lateral surface
•
Medial surface
•
Anterior surface
•
Posterior surface
•
Inferior surfaces
•
LATERAL SURFACE
•
Present styloid process
•
Radial collateral ligament of wrist joint is attached at tip of styloid process
•
Brachiodialis is inserted into lower part of lateral surface
•
Two grooves lateral to styloid process for tendons of Abductor pollicis longus
&Extensor pollicis brevis
MEDIAL SURFACE
•
•
Bears ulnar notch for articulation with head of ulna
Articular disc of inferiorradio-ulnar joint is attached to ridge at lower part.
ANTERIOR SURFACE
•
In form of thick prominent ridge
•
Radial artery is palpated as radial pulse
•
Pronator quadratus is inserted into the lower part of anterior surface
POSTERIOR SURFACE
•
Irregular
•
Present dorsal tubercle(of lister)
•
Four grooves for extensor tendons
INFERIOR SURFACE
•
Bears triangular area for Scaphoid bone
•
Medially, quadrangular area for Lunate
•
Takes part in forming wrist joint
CLINICAL ANATOMY
Fractures of radius
Fracture of head
•
Can occur from fall on outstretched hand
Fracture of neck of radius
•
Occur in young children
FRACTURES OF SHAFT OF RADIUS
•
May or may not occur with ulna
•
Displacement of fractured fragment depends on pull of muscle
•
Supinator and biceps supinate the proximal fragment
•
Pronator quadratus pronates the distal fragment
•
Brachioradialis and extensor carpi radialis and brevis shortens the fore arm
COMBINE FRACTURES OF RADIUS AND
ULNA
•
•
•
Shaft of ulna fractured by a force from behind
Bowing forward of ulnar shaft with anterior dislocation of radial head
Rupture of annular ligament
COMBINE FRACTURES OF RADIUS AND
ULNA
•
Proximal third of radius is fractured
•
Distal end of ulna is dislocated at distal radio
ulnar joint
FRACTURES OF DISTAL END
Colles’ fracture
•
Fall on outstretched hand
•
Distal fragment is displaced posteriorly and superiorly
•
The fore arm and wrist resembles the shape of dinner fork
•
Dinnerfork deformity
•
Reverse colles’s fracture
•
Distal fragment displaced anteriorly
•
Fall on back of hand
•
BONES OF HAND
•
Eight carpal bones
•
Five metacarpal bones
•
Fourteen phalanges
CARPAL BONES
•
Eight carpal bones
•
Arranged in two rows
Proximal row
Medial to lateral
•
Scaphoid
•
Lunate
•
Triquetral
•
Pisiform
Distal row
•
Trapezium
•
Trapezoid
•
Capitate
•
Hamate
CHARACTERISTICS OF EACH BONE
Each bone has six surfaces.

Scaphoid is boat –shaped
•
tubercle on its lateral side

Lunate is half moon shaped or crescentic

Triquetral is pyramidal shape
•
has oval facet on distal part of palmar surface

Pisiform is pea shaped
•
only one oval facet on proximal part of dorsal surface

Trapezium is quadrangular in shape
•
crest & groove anteriorly

Trapezoid resemble shoe of baby

Capitate is largest with rounded head

Hamate is wedge –shaped with hook near base
ATTACHMENTS
Most important structure related with carpal bones --------- FLEXOR RETINACULUM
Attachment:
Lateral
scaphoid
anterior border of lower end
Medial
•
Pisiform
•
Hamitate
•
•
CLINICAL ANATOMY
Fracture of scaphoid
•
•
•
Most common fractured bone among carpal bone
Non union & avascularity common problem
Tenderness & swelling in anatomical snuff box
Dislocation of lunate
•
•
•
•
Most common dislocated bone of carpal bone
May compress median nerve in front of wrist
Carpal tunnel syndrome
CARPAL TUNNEL SYNDROME
Carpal tunnel:
•
osseofibrous space formed by anterior concave surface of carpus and flexor
retinaculum
•
Passage of long flexor tendon and median nerve
CARPAL TUNNEL
SYNDROME
•
Syndrome is caused by compression of median nerve
due to reduced size of canal
•
Pain and paraesthesia of lateral one and half finger
•
Weakness of thenar muscle
METACARPAL BONES
•
Short long bones
•
Numbered from lateral to medial side
•
1st metacarpal Shorter & thicker articulates with trapezium.
Other metacarpal bones
•
Expanded bases articulate with distal row of carpal bones & with each
other
•
Middle metacarpal show styloid process
•
Heads has boldly rounded articular facets
•
Form concavity for palm
•
Heads form knuckles of fist
PHALANGES
14 in number
Parts

Base

Shaft

Head