Elbow joint

Dr JINO JUSTIN.J
Radiology Resident
RMMCH

Introduction
Anatomy of the ELBOW joint.
Ossification of Bones.
X ray Projections.
Major Lines in X ray joint.
Fracture Classification.
Common fractures and Dislocations.
Conclusion.

 Compound Synovial Joint
 Distal end of humerus and Proximal
end of Radius & Ulna
 Formed by three joints
 Humeroulnar joint (ulna trochlear)
 Humeroradial joint (radio
capitellar)
 Proximal radio ulnar joint
 Most upper extremity movements
involve the elbow & radioulnar joints
 These two joints are usually grouped
together due to close anatomical
relationship

The long mid center of the humerus is the
body (shaft), and the humeral condyle is its
expanded distal end.
Articular part of the humeral condyle is
made up of trochlear and the capitulum.
Trochlear is more medial and articulates
with the ulna.
Capitulum is more lateral and will
articulate with head of radius.
Lateral epicondyle is a small projection on
lateral aspect of distal humerus.
 Medial epicondyle (larger and more
prominent) is located on medial edge of
distal humerus.

 Anterior depressions:
Coronoid fossa and radial
fossa.
Posterior depression: is the
olecranon fossa.
Lateral view of elbow shows
proximal radius and ulna with
radial head and neck and
radial tuberosity.

 Radioulnar joint
 Trochoid or pivot-type
joint
 Radial head rotates
around at proximal
ulna
 Distal radius rotates
around distal ulna
 Annular ligament
maintains radial head
in its joint

Radioulnar joint
 Supinate 80 to 90 degrees from neutral
 Pronate 70 to 90 degrees from neutral

Radioulnar joint
Joint between shafts of
radius & ulna held tightly
together between
proximal & distal
articulations by an
interosseus membrane
(syndesmosis)

 Key bony landmarks
 Medial epicondyle
 Lateral epicondyle
 Lateral supracondylar ridge

 Bony landmarks
 Medial condyloid ridge
 Olecranon process
 Coronoid process
 Radial tuberosity

• Elbow motions
• primarily involve movement between articular surfaces
of humerus & ulna
• specifically humeral trochlear fitting into ulna trochlear
notch
• radial head has a relatively small amount of contact
with capitulum of humerus
• As elbow reaches full extension, olecranon process is
received by olecranon fossa
• increased joint stability when fully extended

 As elbow flexes 20 degrees
or more, its bony stability is
unlocked, allowing for more
side-to-side laxity
 Stability in flexion is more
dependent on the lateral
(radial collateral ligament) &
the medial or (ulnar collateral
ligament)

LIGAMENTS OF THE JOINT
 Stability of joints maintained by ligaments.
1. Radial collateral ligament
2. Ulnar collateral ligament :
Anterior bundle
Posterior bundle
Oblique bundle
3. Annular ligament: that wraps around the
radial head and holds it tight against the ulna.

Ulnar Collateral Ligament
 Ulnar collateral ligament is
critical in providing medial
support to prevent elbow
from abducting when
stressed in physical
activity
 Many contact sports &
throwing activities place
stress on medial aspect
of joint, resulting in injury

Radial Collateral Ligament
 Radial collateral ligament
provides lateral stability & is
rarely injured

Annular Ligament
Annular ligament
provides a sling
effect around
radial head for
stability.

 Flexion
 Movement of forearm to
shoulder by bending the elbow
to decrease its angle
 Extension
 Movement of forearm away from
shoulder by straightening the
elbow to increase its angle

 Pronation
 Internal rotary movement of
radius on ulna that results in
hand moving from palm-up
to palm-down position
 Supination
 External rotary movement
of radius on ulna that results
in hand moving from palm-down
to palm-up position

 Elbow flexors
 Biceps brachii
 Brachialis
 Brachioradialis
 Weak assistance from
Pronator teres
 Elbow extensor
 Triceps brachii
 Anconeus provides
assistance
 Radioulnar pronators
 Pronator teres
 Pronator quadratus
 Brachioradialis
 Radioulnar supinators
 Biceps brachii
 Supinator muscle
 Brachioradialis

Anterior
 Primarily flexion &
pronation
Biceps brachii
Brachialis
Brachioradialis
Pronator teres
Pronator quadratus

Posterior
 Primarily extension
& supination
 Triceps brachii
 Anconeus
 Supinator

 All elbow & radioulnar joints muscles are innervated
from median, musculotaneous, & radial nerves of
brachial plexus

 Radial nerve - originates
from C5, C6, C7, & C8
 Triceps brachii
 Brachioradialis
 Supinator (posterior
interosseous nerve)
 Anconeus
 Sensation to
posterolateral arm,
forearm, & hand

 Median nerve - derived from
C6 & C7
 Pronator teres
 Pronator quadratus
(anterior interosseus
nerve)
 Musculotaneous nerve -
branches from C5 & C6
 Biceps brachii
 Brachialis

 Biceps tendon anteriorly (allows elbow to flex with
force)
 Triceps tendon posteriorly (allows elbow to extend
with force)

 The articular surfaces are connected together by a
capsule
 Anterior part – from radial and coronoid fossa of
humerus to coronoid process of ulna and annular
ligament of radius
 Posterior part – from capitulum, olecranon fossa, and
lateral epicondyle of humerus to annular ligament of
radius, olecranon of ulna, and posterior to radial
notch.

 Capitelum - (1-2yrs)
 Medial epicondyle - 4yrs
 Trochlea - 8 yrs
 Lateral epicondyle - 10 yrs

1. LATERAL VIEW
2. ANTERO-POSTERIOR VIEW
3. LATERAL OBLIQUE VIEW
4. MEDIAL OBLIQUE VIEW

Demonstrates: Distal humerus,
proximal ulna, proximal radius,
and elbow joint.
Measure: AP through the elbow
at the epicondyles.
kVp: 55 (50 to 60).
Film Size: 10 × 12 inches (24 × 30
cm)

Patient Position: Seated, with body
rotated away from the table. Apply a lead
half apron for gonad protection.
Part Position: Arm fully extended, and
the hand supinated. If the elbow cannot be
extended, two APs are done, one with the
forearm on the film and the second with the
humerus on the film.
CR: To the elbow, between and 1 inch
below the level of the epicondyles.
Breathing Instructions: Suspended
expiration.

Demonstrates: Distal
humerus, proximal ulna,
proximal radius, and elbow
joint.
Measure: At the CR.
kVp: 55 (50 to 60).
Film Size: 10 × 12 inches
(24 × 30 cm),

Patient Position: Seated, with the body rotated
away from the table. Apply a lead half apron for
gonad protection.
Part Position: Elbow flexed to 90°, with the ulnar
surface of the forearm flat on the film. The hand is
in the true lateral position. The humerus must also
be parallel to the film plane, with the shoulder
abducted to 90°.
CR: Mid-elbow joint, just anterior to the lateral
epicondyle.
Breathing Instructions: Suspended expiration

 POSITIONING OF PATIENT
 Extend the limb as in AP view
 Center the mid point of cassette to
the elbow joint
 Rotate the hand laterally to place the
posterior surface of elbow at an angle
of 40 degree.
Central ray perpendicular to elbow
joint.
 Demonstrates FRACTURE of
lateral epicondyle & radial head.

STRUCTURE SHOWN
 Oblique image of the elbow with radial head free of
superimposition of ulna
EVALUATION CRITERIA
 Radial head, Neck and tuberosity projected free of ulna
 Elbow joint should be open.

Synonyms: AP Internal Oblique.
Demonstrates: Distal humerus,
proximal ulna, proximal radius, and
elbow joint.
Measure: At the CR.
kVp: 55 (50 to 60).
Film Size: 10 × 12 inches (24 × 30
cm)

Patient Position: Seated, with body
rotated away from the table. Apply a lead
half apron for gonad protection.
Part Position: Arm fully extended and
the forearm pronated.
CR: 1 inch below the epicondyles.
Breathing Instructions: Suspended
expiration.

1. Shaft of the humerus.
2. Olecranon fossa,
humerus.
3. Medial epicondyle,
humerus.
4. Lateral epicondyle,
humerus.
5. Supracondylar ridge.
6. Olecranon process, ulna.
7. Coronoid process, ulna.
8. Radial head.

CARRYING ANGLE
 It is the angle at which the
humerus and forearmarticulate,
with the elbow in full extension,
and the palms facing forward.
 The carrying angle permits the arm
to be swung without contacting the
hips.
Normal values.
Males=15 deg
Female=20 deg

 A line in the longitudinal axis
of proximal end of radius
passes to the centre of
capitulum.
 A line in the Anterior cortex of
distal end of humerus passes
to the centre of capitulum
 Distruption from this
indicates Fracture or
Dislocation.

Approximately 6% of all fractures and dislocations involve the elbow.
 The frequency of injury at various sites around the elbow differ between
adults and children
LOCATION INCIDENCE LOCATION INCIDENC
E
RADIAL HEAD
& NECK
50% SUPRACONDYLA
R
60%
OLECRANON 20% LATERAL
EPICONDYLE
15%
SUPRACONDY
LAR
10% MEDIAL
EPICONDYLE
10%
FRACTURES -
DISLOCATION
15%

 X-ray :
 AP view & Lateral View
 gentle traction x-ray help in: -
 - accurate Diagnosis
 -classification
 - pre-operative planning

DISTAL HUMERUS:
FRACTURES:
SUPRACONDYLAR
INTERCONDYLAR
CONDYLAR
EPICONDYLAR
FRACTURES OF
PROXIMAL ULNA:
OLECRANON
FRACTURE
CORONOID PROCESS
FRACTURE
FRACTURES
OF RADIUS:
RADIAL HEAD
RADIAL NECK

This is the most
common fracture to
occur around the elbow
in children (60%).
Usually, the distal
fracture fragment
displaces posteriorly.

The fracture
line extends
transversely or
obliquely through
the distal
humerus above
the condyles.

Intercondylar Fracture.
The fracture line extends
between the medial and lateral
condyles and communicates with
the supracondylar region.
The resultant fracture line may
take on a T or Y configuration.
This type of fracture in adults
accounts for at least 50% of distal
humerus fractures.

The transverse fracture line
that passes through both
humeral condyles is called
a transcondylar fracture.
A comminuted fracture of the
distal humerus, usually with
associated ulnar and radial
fractures, may occur if an object
is struck with the elbow
protruding from a car window

Condylar Fracture.
A single condyle may be sheared off
owing to an angular force through the
elbow.
 Fractures may occur along the
articular surfaces of the capitellum and
trochlea.
The convex surface of the capitellum
is particularly susceptible to
compression and breakage .
The radial head and capitellum are
occasionally fractured simultaneously.

Epicondylar Fracture.
Separation of the medial epicondyle is a
common injury in sports in which strong
throwing actions are performed, such as
baseball.
Epicondylar fractures are usually avulsive
injuries from traction of the respective
common flexor or extensor tendons and
collateral ligaments on the medial or lateral
epicondyles.

Mechanism:
 Head of radius impacted to
capitulum fracture.

Classification:
 Type I: large fragment of
bone and articular surface
(involves trochlea) are
fractured.
 Type II: small shell of
bone and articular surface
(not involves trochlea).
 Type III: comminuted
fracture.

Fractures of the
Proximal Ulna

 Mechanism Of injury :
 Direct: fall on the flexed elbow, and
this frequently produces comminution
and marked displacement of the major
fragments
 Indirect: fall on the outstretched arm,
produces an oblique or transverse
fracture with minimal displacement
 Imaging: Well demonstrated on a
lateral projection of the elbow.

It indicates severe
trauma to elbow.
Mechanism of injury:
- Striking of trochlea
in coronoid.
- avulsion (less
common).

Classification:
 Type I: simple
avulsion of tip.
 Type II: involve <50%.
 Type III :involve
>50%.

 It is common in adults.
Mechanism of
Injury:
F.O.S.Hwhile arm is
pronated, head
impacted in capitulum.

 Mason Classification
of radial head:
 Type I: undisplaced.
 Type II: displaced.
 Type III:Comminuted.
 Type IV: # associated
with posterior
elbow dislocation &
coroniod fracture.

Radial Neck Fracture
The most common radial neck fracture is
an impaction at the junction of the head and
neck.
The only sign may be a sharpened angle on
the anterior surface, best depicted on the
lateral projection.
Complete fractures will be readily seen as a
transverse lucent line with varying degrees
of displacement.

Fat-pad sign
It is the clear depiction of
displaced humeral capsular fat
pads.
In the normal elbow a layer of
fat (fat pad) lies between the
synovial and fibrous layers of
both the anterior and posterior
joint capsule.
In the lateral projection of
the normal elbow, the anterior
fat pad is seen as an obliquely
oriented radiolucency.

When acute intracapsular
swelling is present from any
origin , the anterior fat pad is
elevated to be oriented
horizontally, and the posterior fat
pad becomes visible (fat-pad
sign)
the posterior fat pad, when
visible, is the most reliable sign
of intra-articular effusion.

Dislocation of elbow joint.
 Form 20% of joint dislocation (after shoulder& finger)
 classification: posterior [most common 80%]
-ant. - med. - lat. - divergent. [rare].
posterior or post.lat. dislocation :
mech of injury. :FOSH while elbow extended.
Diagnosis: -Clinically it may be associated with
neurovascular injury
(median & ulnar n. &brachial artery.)

Tennis Elbow
 “Tennis elbow" - common problem usually
involving extensor digitorum muscle near
its origin on lateral epicondyle
 known lateral epicondylitis
 associated with gripping & lifting
activities

Medial Epicondylitis
Somewhat less common
 Also known as golfer's elbow
Associated with medial wrist flexor & pronator group
near their origin on medial epicondyle.
 Involves muscles which cross elbow but act
primarily on wrist & hand

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