AN13.1-8 | General Features, Joints, radiographs & surface marking (Upper Limb) — Glossary

The fatty subcutaneous layer containing cutaneous nerves, superficial veins, and lymphatic vessels

A tough dense layer wrapping muscles like a sleeve, sending inward projections as intermuscular septa to create compartments

A surgical emergency where swelling within a closed fascial compartment raises pressure dangerously, compressing nerves and vessels

A tough fibrous sheet in the palm that helps grip objects by anchoring the skin to underlying structures

An area of skin supplied by sensory fibres from a single spinal nerve root

The angle between the arm and forearm when the elbow is extended and supinated, normally 5-15 degrees of valgus

A ring-shaped ligament encircling the head of the radius at the proximal radio-ulnar joint, holding it in the radial notch of the ulna

Subluxation of the radial head from the annular ligament in young children, caused by sudden traction on the forearm

Triangular fibrocartilage complex, an articular disc separating the distal radio-ulnar joint from the wrist joint

A biaxial synovial joint where both surfaces are concavo-convex, as seen in the first CMC joint of the thumb

A strong ligament with conoid and trapezoid components that stabilises the AC joint by connecting the coracoid process to the clavicle

The hand splinting position with MCPs flexed 70-90 degrees and IPs extended, preventing collateral ligament contracture

Three smooth arcs traced through the carpal bones on PA radiograph; disruption suggests carpal instability or fracture

A line along the anterior cortex of the humerus on lateral elbow X-ray that should pass through the middle third of the capitulum

Mnemonic for elbow ossification centres appearing in order: Capitulum (1yr), Radial head (3yr), Internal epicondyle (5yr), Trochlea (7yr), Olecranon (9yr), External epicondyle (11yr)

A clinical test assessing the patency of the palmar arches by sequentially releasing radial and ulnar arteries after blanching the hand

A thickened ridge of ectoderm at the tip of the developing limb bud that drives proximal-to-distal limb growth via FGF signalling

A severe limb malformation where hands or feet are attached directly to the trunk, with absent or severely shortened long bones

The angle of Louis at the manubriosternal junction, marking the level of the 2nd costal cartilage and T4/T5 disc

A lymph node above the medial epicondyle that drains the medial hand and forearm; enlargement suggests infection or lymphoma

A tough fibrous sheet connecting the radius and ulna, providing attachment for deep forearm muscles and transmitting forces

A superficial vein on the lateral side of the upper limb draining into the axillary vein through the deltopectoral groove

A common carpal fracture with tenderness in the anatomical snuffbox; risk of avascular necrosis due to retrograde blood supply