Trauma and orthopaedics (5): The elbow Flashcards
osteology of the humerus
do a purpose games
The long bone of the upper arm
- Extends from the shoulder to the elbow
- Proximal aspect articulates with the glenoid fossa of the scapula- glenohumeral joint
- Distally, at the elbow joint, the humerus articulates with the head of the radius and trochlear notch of the ulnar
elbow joint
- Hinge-type synovial joint
2 separate articulations:
- Trochlear notch of the ulna and the trochlea of the humerus
- Head of the radius and the capitulum of the humerus
joint capsule of elbow
Like all synovial joints, the elbow joint has a capsule enclosing the joint
- Strong and fibrous- strengthening the joint
- Thickened medially and laterally to form collateral ligaments- stabilise the flexing and extending motion of the arm
bursae of the elbow
- Membranous sac filled with synovial fluid
- Acts as a cushion to reduce friction between the moving parts of a joint, limiting degenerative damage.
- Key bursae of the elbow
- Intratendinous- located within the tendon of the triceps brachii
- Subtendinous- between the olecranon and the tendon of the triceos brachii, reducing friction between the two structures during extension and flexion of the arm
- Subcutaneous (olecranon) bursa- between the olecranon and the overlying connective tissue
ligaments of the elbow
Joint capsule of the elbow is strengthened by ligaments medially and laterally.
-
Radial collateral ligament (lateral)
- Extends from the lateral epicondyle, blending with the annular ligament of the radius
- Ulnar collateral ligament (medial) originates from the medial epicondyle and attaches to the coronoid process and olecranon of the ulnar
arterial supply of the elbow joint
supply to the elbow joint is from the cubital anastomosis, which includes recurrent and collateral branches from the brachial and deep brachial arteries.
nervous supply of the elbow
Its nerve supply is provided by the median, musculocutaneous and radial nerves anteriorly, and the ulnar nerve posteriorly.
Movement of the elbow
Orientation of the bone forming the elbow joint produces a hinge type synovial joint- allows for extension and flexion of the forearm
- Extension- triceps brachii and anconeus
-
Flexion- brachialis, biceps brachii, brachioradialis
*
the upper arm contains 4 muscle
do a purpose games
- 3 in the anterior compartment (biceps brachii, brachialis, coracobrachialis)
- 1 in the posterior compartment (triceps brachii)
All innervated by the musculocutaneous nerve. Good way to remember: BBC- Biceps, Brachialis, coracobrachialis. Arterial supply- muscular branches of the brachial artery.
areas of the elbow
cubital fossa
cubital fossa
An area of transition between the anatomical arm and the forearm- located as a depression the anterior surface of the elbow joint.
borders of the cubital fossa
Triangular shape:
- Lateral border- medial border of the brachioradialis
- Medial border- lateral border of the pronator teres muscle
- Superior border- hypothetical line between the epicondyles of the humerus
- Floor- formed proximally by the brachialis and distally by the supinator muscle
-
Roof- skin and fascia, reinforced by the bicipital aponeurosis
- Within the floor runs the median cubital vein- accessed for venepuncture
Olecranon bursitis
refers to inflammation and swelling of the bursa over the elbow. The olecranon is the bony lump at the elbow, which is part of the ulna bone.
pathophysiology of bursitis
Bursitis is inflammation of a bursa. This causes thickening of the synovial membrane and increased fluid production, causing swelling.
This inflammation can be caused by a number of things:
- Friction from repetitive movements or leaning on the elbow
- Trauma
- Inflammatory conditions (e.g., rheumatoid arthritis or gout)
- Infection – referred to as septic bursitis
olecranon bursitis also known as
“student’s elbow”, as students may lean on their elbow for prolonged periods while studying, resulting in friction and mild trauma leading to bursitis. It can also occur with people with occupations that require leaning on the elbow, such as plumbers or drivers.