The elbow joint is a synovial hinge joint that connects the forearm to the arm. It consists of the trochlea of the humerus articulating with the trochlear notch of the ulna, and the capitulum of the humerus articulating with the head of the radius. The elbow joint is stabilized by ligaments and surrounded by a joint capsule, and allows for flexion and extension of the forearm. Common injuries to the elbow include dislocations, fractures, and inflammation like tennis elbow.

1. Elbow joint
Dr M Idris SiddiquiDr M Idris Siddiqui

3. Elbow joint
• The elbow is the joint connecting
the proper arm to the forearm.
• It is marked on the upper limb by
the medial and lateral epicondyles,
and the olecranon process.

6. Elbow joint
•Structurally, the joint is
classed as a synovial joint,
and functionally as
a hinge joint.

7. Articulating Surfaces
• It consists of two separate articulations:
• Trochlear notch of the ulna and the trochlea
of the humerus
• Head of the radius and the capitulum of
the humerus.
• Articulating Surfaces are covered by hyaline
catilage.
–Note: The proximal radioulnar joint is found
within same joint capsule of the elbow, but most
resources consider it as a separate articulation.

8. What is involved in the elbow complex?
• 3 bones –
–Humerus , ulna and radius
• 3 ligaments –
–Medial collateral, lateral collateral and
annular
• 2 joints –
–Ulnohumeral joint and radiohumeral joint
• 1 capsule –
–Synovial joint

11. Joint Capsule
• Like all synovial joints, the elbow joint has a
capsule enclosing the joint.
• This in itself is strong and fibrous,
strengthening the joint.
• The joint capsule is thickened medially and
laterally to form collateral ligaments, which
stabilise the flexing and extending motion of
the arm.
• It is thin anteriorly.

12. The lateral & medial epicondyles are extra apsular.

14. Ligaments
• The joint capsule of the elbow is strengthened by
ligaments medially and laterally.
• The radial collateral ligament is found on the
lateral side of the joint, extending from the lateral
epicondyle, and blending with the annular
ligament of the radius (a ligament from the
proximal radioulnar joint).
• The ulnar collateral ligament originates from
the medial epicondyle, and attaches to the
coronoid process and olecranon of the ulna.

15. Joint Capsule
• Medially, the joint capsule thickens to form the
medial or ulnar collateral ligament, which extends
from the medial epicondyle of the humerus to the
coronoid and olecranon of the ulna.
• The ulnar collateral ligament is a triangular
thickening with 3 main bands:
– The anterior or cordlike band
– The posterior fanlike band
– The oblique band.
• The oblique band also helps to deepen the trochlear notch.

16. Joint Capsule
• Laterally, the lateral or radial collateral ligament
extends from the lateral humeral epicondyle and
distally blends into the anular ligament of the
radius.
– The anular ligament of the radius wraps around the
head of the radius and attaches to the ulna anteriorly
and posteriorly.
– The surface of the anular ligament is lined with synovial
membrane and allows the head of the radius to rotate
inward during supination and pronation, while
maintaining stability of the radial ulnar joint.

18. Bursae
• A bursa is a membranous sac filled with synovial fluid. It
acts to cushion the moving parts of a joint, preventing
degenerative damage. There are many bursae in the
elbow, but only a few have clinical importance:
• Intratendinous – located within the tendon of the
triceps brachii.
• Subtendinous – between the olecranon and the tendon
of the triceps brachii, reducing friction between the
two structures during extension and flexion of the arm.
• Subcutaneous olecranon – between the olecranon and
the overlying connective tissue

21. Neurovasculature
• The arterial supply to the elbow joint is
by the cubital anastamosis, which
includes recurrent and collateral
branches from the brachial and deep
brachial arteries.
• Its nerve supply is provided by
the median, musculocutaneous and
radial nerves anteriorly, and
the ulnar nerve posteriorly.

23. Important Relations
• Anteriorly: The brachialis, the tendon of the
biceps, the median nerve, and the brachial artery
• Posteriorly: The triceps muscle, a small bursa
intervening
• Medially: The ulnar nerve passes behind the
medial epicondyle and crosses the medial
ligament of the joint.
• Laterally: The common extensor tendon and the
supinator.

26. Movements of the Joint
• The orientation of the bones forming the
elbow joint produces a hinge type synovial
joint, which allows for extension and flexion of
the forearm:
– Note – pronation and supination do not occur at the elbow – they
are produced at the nearby radioulnar joints.
Flexors Triceps brachii
Anconeus
Extensors Brachialis
Biceps brachii
Brachioradialis

27. 3 brachi muscles
• Brachialis
• Biceps brachii
• Coracobrachialis
–All supplied by musculocutaneous
nerve

29. Stability of Elbow Joint
• The elbow joint is stable because of the wrench-
shaped articular surface of the olecranon and the
pulley-shaped trochlea of the humerus.
• it also has strong medial and lateral ligaments.
• In extension, the medial and lateral epicondyles and
the top of the olecranon process are in a straight
line; in flexion, the bony points form the boundaries
of an equilateral triangle.

30. Palpable structures around elbow
• Bone:
– Epicondyles of humerus(lateral & medial)
– Olecranon tip
– Head of radius
• Tendons:
– Biceps tendon in flexed position
• Artery:
– Brachial
• Nerves:
– Median (just medial to Brachial artery)
– Ulnar(posteromedial to medial epicondyle)

31. Clinical Relevance: Injuries to the
Elbow Joint
• Bursitis
• Subcutaneous bursitis: Repeated friction and
pressure on the bursa can cause it become
inflamed. Because this bursa lies relatively
superficially, it can also become infected (e.g cut
from a fall on the elbow), and this would also
cause inflammation
• Subtendinous bursitis: This is caused by repeated
flexion and extension of the forearm, commonly
seen in assembly line workers. Usually flexion is
more painful as more pressure is put on the bursa.

34. Dislocation
• An elbow dislocation usually occurs when a young
child falls on a hand with the elbow flexed. The
distal end of the humerus is driven through the
weakest part of the joint capsule, which is the
anterior side. The ulnar collateral ligament is usually
torn and there can also be ulnar nerve involvement
• Most elbow dislocations are posterior, and it is
important to note that elbow dislocations are
named by the position of the ulna and radius, not
the humerus.

35. Epicondylitis (Tennis elbow or Golfer’s
Elbow)
• Most of the flexor and extensor muscles in the
forearm have a common tendinous origin. The
flexor muscles originate from the medial
epicondyle, and the extensor muscles from the
lateral. Sportspersons can develop an overuse
strain of the common tendon – which results in
pain and inflammation around the area of the
affected epicondyle.
• Typically, tennis players experience pain in the
lateral epicondyle from the common extensor
origin. Golfers experience pain in the medial
epicondyle from the common flexor origin.

37. Flexion
mediated by
Musculocutaneous nerve
Radial nerve
Median nerve
Extension
mediated by
Radial nerve
Pronation
mediated by
Median nerve
Supination
mediated by
Musculocutaneous nerve
Radial nerve

39. Supracondylar Fracture
• A supracondylar fracture occurs by falling on a
flexed elbow. It is a transversefracture, spanning
between the two epicondyles.
• Direct damage, or swelling can cause the
interference to the blood supply of the forearm via
the brachial artery. The resulting ischaemia can
cause Volkmann’s ischaemic contracture –
uncontrolled flexion of the hand, as flexors muscles
become fibrotic and short. There also can
be damage to the medial, ulnar or radial nerves.