Wrist, hand, and fingers anatomy

What muscle group originates from the medial epicondyle?

Common Flexor Tendon (CFT) group

What muscle group originates from the lateral epicondyle?

Common Extensor Tendon (CET) group

Which two processes of the ulna articulate with the humerus?

The olecranon process (with the olecranon fossa) and the coronoid process (with the coronoid fossa)

What are the three joints of the elbow contained within a single capsule?

Humeroulnar, humeroradial, and proximal radioulnar joints

What is the primary function of the annular ligament?

To keep the radial head in place during rotation

Which ligament resists valgus force at the elbow?

Ulnar Collateral Ligament (UCL)

Which ligament resists varus force at the elbow?

Radial Collateral Ligament (RCL)

What are the three muscles of the anatomical snuffbox?

Abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus

Which nerve is known as the 'funny bone' and is most exposed at the elbow?

Ulnar nerve

What is the carrying angle of the elbow in men and women?

5-10 degrees valgus for men; 10-15 degrees valgus for women

What is cubital recurvatum?

Normal hyperextension of the elbow beyond 0 degrees

What is the normal end-feel for elbow flexion?

Soft (muscle on muscle)

What is the normal end-feel for elbow extension?

Hard (bone on bone)

What is the normal range of motion for elbow flexion?

0-145/155 degrees

What is the normal range of motion for pronation and supination?

0-90 degrees for each

What is the mechanism of injury (MOI) for most elbow dislocations?

FOOSH (Fall On Outstretched Hand)

What constitutes the 'terrible triad' of the elbow?

Posterior dislocation, radial head fracture, and coronoid fracture

What is the immediate management protocol for an elbow dislocation?

Splint, monitor vitals, and refer; never attempt to reduce the dislocation

What is the primary MOI for a UCL injury?

Valgus overload (acute or repetitive)

What clinical sign often indicates a UCL injury?

Medial pain that intensifies with motion and potential 'gapping'

What is the primary MOI for an RCL injury?

Varus stress

What is the primary cause of 'Golfer's Elbow'?

An overuse injury.

What is 'Little Leaguer's Elbow'?

Apophysitis involving bone damage and shearing where a ligament rips off a chunk of bone.

What are the three primary causes of nerve pathologies in the arm?

Chronic entrapment, repetitive tension, and trauma.

What happens to pressure in the cubital tunnel during elbow and wrist flexion?

It increases three times.

What is Wartenburg's sign?

A chronic deficit where the 5th finger rests in abduction.

What are the '5 P's' of compartment syndrome?

Pain, pallor, paresthesia, paralysis, and pulselessness.

What is Volkmann's Ischemic Contracture?

A permanent flexion contracture of the wrist and fingers caused by ischemia lasting more than 6-12 hours.

Which nerve provides sensation to the back of the hand and fingers 1-3?

The radial nerve.

What is the function of the Triangular Fibrocartilage Complex (TFCC)?

It acts as the 'meniscus of the wrist' and absorbs 40% of the force applied to the wrist.

What is a subungual hematoma?

Bruising occurring under the fingernail.

What three structures form the anatomical snuff box?

Extensor pollicis longus, extensor pollicis brevis, and abductor pollicis brevis.

Why are scaphoid fractures slow to heal or prone to non-union?

They have a poor blood supply.

What is a 'Boxer's Fracture'?

A fracture to the 5th metacarpal.

What is the function of the volar plate?

A dense ligament that prevents hyperextension of the fingers.

What is 'Jersey Finger'?

An injury where the patient cannot flex the distal interphalangeal joint, often caused by forced hyperextension.

What is 'Mallet Finger'?

An avulsion of the extensor tendon where the distal phalanx cannot extend.

What characterizes a 'Boutonniere Deformity'?

Rupture of the central slip of the extensor digitorum tendon, resulting in DIP hyperextension and PIP flexion.

What is 'Trigger Finger'?

A condition characterized by the formation of nodules that cause a snapping or jumping sensation when moving the finger.

What is 'Gamekeeper's Thumb'?

A sprain or avulsion of the ulnar collateral ligament (UCL) of the thumb caused by forced hyperextension.

What is Dupuytren's Contracture?

A hereditary flexion contracture of the MCP and PIP joints caused by shortening or adhesion of the palmar fascia, typically affecting fingers 4 and 5.

What causes a 'Claw Deformity'?

Injury to both the median and ulnar nerves, leading to paralysis and wasting of intrinsic muscles.

What is 'Bishop's Deformity'?

A condition caused by ulnar nerve inhibition, resulting in atrophy of hypothenar and interossei muscles and a flexed posture of fingers 3-5.

What is 'Ape Hand'?

A deformity caused by median nerve inhibition, characterized by thenar eminence atrophy and the thumb sitting close to the 2nd finger.

What is the primary MOI for a Colles' fracture?

A fall on an outstretched hand (FOOSH).