2 - Aldridge - Anterior and Posterior Forearm

Question 1

What is orientation of radius to ulna in supination?

Answer 1

Parallel

Question 2

Answer 2

Question 3

What is the orientation of forearm bones during pronation?

Answer 3

Radius crosses anterior to Ulna during pronation

Question 4

Answer 4

Question 5

Answer 5

Question 6

Answer 6

Question 7

Which is greater in the hand–adduction or abduction, and why?

Answer 7

Adduction > Abduction

Due to longer length of the radius vs ulna

Question 8

Scaphoid Fracture

Answer 8

Fracture through middle of scapoid disrupts blood supply to proximal half, resulting in ischemic necrosis

Palmar carpal branch of radial artery enteres distal half in 10% of population

Question 9

Carpal Tunnel Contents

Answer 9

1. Long Flexor Tendons (to middle 4 fingers)
2. Flexor Pollicis Longus (long flexor tendon to thumb)
3. Median Nerve

Question 10

Innervation and action of anterior compartment of forearm?

Answer 10

Action:

Flexor / Pronator

Innervation:

All Median

Exception - Flexor Carpi Ulnaris innervated by ulnar nerve

Question 11

Superficial Group of Anterior Forearm

Answer 11

1. Pronator Teres
2. Flexor Carpi Radialis
3. Palmaris Longus
4. Flexor Carpi Ulnaris (Ulnar N.)

Question 12

Intermediate Group of Anterior Forearm

Answer 12

Flexor Digitorum Superficialis

Pass through carpal tunnel

Each tendon of insertion splits into two slips to leave gap for long tendons

Question 13

Deep Group of Anterior Forearm

Answer 13

1. Flexor Digitorum Profundus (carpal tunnel)
2. Flexor Pollicis Longus (carpal tunnel)
3. Pronator Quadratus (flat square muscle)

Question 14

Flexor Digitorum Profundus innervation

Answer 14

Lateral Half: Median Nerve

Medial Half: Ulnar Nerve

Tendons of insertion pass through two tendinous slips of flexor digitorum superficialis

Question 15

What surrounds tendons in the hand and wrist to prevent wear and tear?

Answer 15

Synovial Sheaths

Question 16

Trigger Finger

Answer 16

Thickening of a fibrous digital sheath on the palmar aspect of the digit

Flexor Digitorum Longus/Flexor Digitorum Superficialis can catch on fibrous digital sheath

Patient has difficulty extending phalanges at interphalangeal joints

Question 17

Risk Factors for Trigger Finger

Answer 17

Occupation or hobbies that involve repetitive hand use, prolonged gripping

Patients w/Rheumatoid Arthiritis

Question 18

What muscles allow Supination to Pronation?

What muscles allow Protation to Supination?

Answer 18

Supination to Pronation:

Pronator Teres

Pronator Quadratus

Pronation to Supination:

Supinator

Biceps Brachii

Question 19

Major branches of median nerve in forearm?

Answer 19

Anterior Interosseous Nerve: Originates between two heads of Pronator Teres

Palmar Cutaeous Branch of Median Nerve: Originates proximal to Flexor Retinaculum

Question 20

Major branches of Ulnar Nerve in forearm

Answer 20

Palmar Cutaneous Branch

Dorsal Cutaneous Branch

Question 21

Common Action of Posterior Compartment of Forearm

Answer 21

Extensors and Supinators

Question 22

Muscles of Superficial Group of Posterior Forearm

Answer 22

1. Brachioradialis (flexor innervated by radial nerve)
2. Extensor Carpi Radialis Longus
3. Extensor Carpi Radialis Brevis
4. Extensor Digitorum
5. Extensor Digiti Minimi
6. Extensor Carpi Ulnaris
7. Anconeus

Question 23

Insertions of muscles of posterior forearm

Answer 23

Tendons split into a central slip that inserts on middle phalanx and two side slips that insert on distal phalanx

Question 24

Mallet Finger

Answer 24

Rupture of side slips of extensor digitorum that inserts on distal phalanx of fingers due to hyperflexion of DIP joint

Distal phalanx is flexed due to tear of lateral slips of extensor expansion and unopposed action of long flexors

TIP OF FINGER FLEXED

Question 25

Boutonniere Deformity

Answer 25

Hyperflexion of **PIP** joint and hyperextension of **DIP** joint due to trauma to dorsum of finger - - - Rupture of **central tendon of extensor expansion** **- - -** **MIDDLE OF FINGER FLEXED**

Question 26

Muscles of Deep Group of Posterior Forearm

Answer 26

1. Supinator 2. Abductor Pollicis Longus 3. Extensor Pollicis Brevis 4. Extensor Pollicis Longus 5. Extensor Indicis

Question 27

Extensor Retinaculum

Answer 27

Transverse thickening of deep fascia, holds extensor tendons in place

Question 28

Branches of radial nerve in forearm

Answer 28

Superficial Branch: Descends in Anterior Forearm deep to brachioradialis Sensory to dorsolateral hand and dorsal sides of proximal part of lateral 3.5 digits Deep Branch: Motor to most muscles of posterior compartment

Question 29

Anatomical Snuffbox

Answer 29

Borders: Abductor Pollicis Longus Tendon Extensor Pollicis Brevis Tendon Extensor Pollicis Longus Tendon Contents: Trapezium and Scaphoid Radial Artery - - - **Radial Pulse can be taken here**

Question 30

What is the only blood vessel that runs through the anatomical snuff box?

Answer 30

Radial artery

Question 31

Fracture of Scaphoid Bone?

Answer 31

Often fall on outstretched hand Presentation: Pain, tenderness, swelling in anatomical snuffbox

Question 32

Damage to radial nerve in radial groove?

Answer 32

Can result in **wrist drop** Can result in loss of sensation on the dorsal medial and slightly thumb palmar side