L4/5 Hand Trauma

Question 1

Why are Extensor Tendon Injuries often missed?

Answer 1

Skin-cut may not align with the tendon section

Communal extensor bands can compensate

To test extensor function, must stop the others and isolate the finger (ie. Devil’s Horn Sign)

Question 2

Zones of Extensor Tendon Injuries?

Answer 2

Even numbers over bones
Odd numbers over joints

Question 3

Answer 3

Question 4

Management of extensor tendon lacerations?

Answer 4

• Careful inspection of wound (+/- local anaesthesia)
• Zones near joints (odd numbers) must have capsules checked (risk of septic arthritis)
• Repair tendons
• Dynamic extension splinting 4-6 weeks (Rigid splint can cause tendinopathy)

Question 5

Answer 5

Question 6

________ test can be used to check the Proximal Interphalangeal Joint Extension.

What is this used to diagnose?

Answer 6

Elson’s Test can be used to check the Proximal Interphalangeal Joint Extension

Useful in diagnosing Boutonniere Deformity (PIP)

Question 7

25 year old female was playing with nephews when one of them threw a hard ball at her. It struck her right ring finger. A few days later after the swelling had subsided the patient presented to her GP and was quite worried about this deformity.

Name of this deformity and test to check it?

Answer 7

ELSON’s Test used to diagnose Boutonniere Deformity (Proximal Interphalangeal Joint):

Need to check if the Lateral bands are still active and able to extend the finger. When opposition is applied to the finger, bend tip of the finger:

• if supple, then central slip still intact
• if unable to bend the tip of finger => reliant on lateral slips as central torn

Question 8

Name of injury to Distal Phalangeal Joint?

Answer 8

Mallet finger (DIP)

Question 9

Injury resulting in failure to flex distal phalanx?

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Injury to ulnar collateral ligament of the metacarpal pharyngeal joint?

Answer 12

Gamekeeper’s thumb = Skier’s thumb

Question 13

A two-piece fracture dislocation of the base of the thumb metacarpal?

Answer 13

Bennett’s Fracture

Down at base of first metacarpal

Skiier’s thumb more distal

Question 14

Comminuted fracture (>2) dislocation of the base of the thumb metacarpal?

Answer 14

Rolando Fracture: comminuted Bennett’s (worse prognosis)

Question 15

Non displaced stable fractures can be treated with ____________

Answer 15

Non displaced stable fractures can be treated with buddy tape

Question 16

________________fractures need open reduction and fixation w/ K Wires

Answer 16

Angulated Condylar fractures need open reduction and fixation w/ K Wires

Question 17

What type of fracture is this?

How to Treat?

Answer 17

Boxer’s Fracture

To heal boxers buddy strap 4/5 and bend at 90* to give collateral ligament tension

Question 18

Pathogenesis of Fight Bites?

What to be wary of?

Answer 18

Polymicrobial: 3/5 anaerobes

• Strep
• Staph aureus
• Eikenella corrodens (gram-negative rod) (30% of infections)

Does it involve synovial sheets w/the potential to spread to other flexors/extensors

Question 19

Answer 19

Question 20

Nerve blocks of hand?

Answer 20

Question 21

Where do digital nerves travel?

Answer 21

Question 22

Answer 22

Question 23

Test for functional Anterior Interosseous branch of the Median nerve?

Answer 23

Question 24

All hand muscles are innervated by Ulnar nerve EXCEPT (5)

Answer 24

Lumbrical 1/Lumbrical 2

Thenar Muscles

• Flexor Pollicis Brevis (superficial head)
• Abductor Pollicis Brevis
• Opponens Pollicis

Question 25

Cause of Ape Hand and Thenar Atrophy?

Answer 25

As Thenar muscles are Innervated by the **recurrent branch of median nerve**, problems with this nerve can lead to Thenar Atrophy Median nerve damage=> Thenar atrophy=> Ape Hand = >Difficult for individual to Abduct thumb

Question 26

What supplies all muscles of the hand except for 5?

Answer 26

Deep Motor Branch of Ulnar Nerve

Question 27

___________ limit hyperextension of MCP joints

Answer 27

Lumbrical muscles limit hyperextension of MCP joints

Question 28

Sign of Ulnar Nerve injury?

Answer 28

Lumbrical muscles limit hyperextension of MCP joints Lumbricals 3/4 are supplied by ulnar (weak) => Hyperextension at rest

Question 29

Sign of Median Nerve Injury?

Answer 29

Question 30

What does Froment’s Sign test for?

Answer 30

**Adductor pollicis innervated by Ulnar Nerve** _Froment's Sign_ (pulling paper from between pinched fingers) is indicative of **Ulnar Nerve Palsy**

Question 31

Conditions that present with “Claw-like hands” that are not ulnar injuries?

Answer 31

**Dupuytren’s Contracture** * Over-proliferating fibroblasts => thickening of palmar aponeurosis * Metacarpal pahregeal joint is NOT hyperextended (can't be ulnar problem) **Volkmann's Contracture** * Damage to vasculature => ischemic damage to muscles=> Wrist and Digits Flexed * Metacarpal pahregeal joint is NOT hyperextended (can't be ulnar problem)

Question 32

What is the Ulnar paradox?

Answer 32

**“The closer to the paw the worse the claw”** In a high ulnar lesion (Elbow) the clawing is paradoxically milder than in a low lesion. This is because in the low lesion (Wrist) the hand muscles are weak but the long flexors which are supplied by the ulnar nerve just below the elbow are not affected. In the high lesion both are weak and the clawing is milder.

Question 33

Hard vs. Soft Signs of Vascular Injury in Orthopedic Trauma?

Answer 33

**Hard Sign** (More Specific Indicator of Condition) * Pulselessness * Pallor * Paresthesia * Pain (Uncontrollable) * Paralysis * Rapidly Expanding Hematoma * Palpable Thrill or Audible Bruit **Soft Sign**: Less specific/diagnostic of injury * History of bleeding * Proximity-related injury * Neurologic finging from nerve adjacent to artery * Hematoma over artery

Question 34

What test assesses profusion of the hand? What is this used for?

Answer 34

**Allen’s Test**: test for profusion of hand shows dominance of ulnar or radial artery issue with one or the other

Question 35

Where does the innervation of the thenar muscles occur?

Answer 35

**Kaplan’s Cardinal Line** Recurrent (Motor) brnach of median nerve enters the thenar muscle mass at this point

Question 36

Normal Capillary Refill time?

Answer 36

Question 37

Measurement of blood flow in hand arteries?

Answer 37

Question 38

Technique for Artery ligation?

Answer 38

**Stick Tie**: Suture through the wall of artery

Question 39

Treatment of Nail bed Injuries?

Answer 39

If <50% of nail area: drain by perforation (sterile needle or hot paper clip) **Nail bed repair** * Remove nail (soak in Betadine) * Suture nail bed with 6-0 suture OR2-octylcyanoacrylate (superglue) * Splint the eponychial fold with original nail * Non adherent gauze **Loss of germinal matrix requires graft**: must be in tact for growth of new nail

Question 40

Name/Treatment of this?

Answer 40

Question 41

Regrowth of Nails?

Answer 41

Germinal Matrix must be intact for growth of new nail

Question 42

The ring finger (fourth digit) A. Has 2 proper digital nerves, continuations of the ulnar nerve B. Would have loss of sensation to the nail bed with injury to the superficial branch of the radial nerve C. May have altered sensation following a focal sharp piercing of carpal tunnel D. Is supplied by the deep ulnar nerve over the medial half of the finger E. Has mixed C7-C8 dermatomal supply

Answer 42

Question 43

Answer 43

Question 44

A girl playing softball cuts the palm of her hand as she scoops up a piece of glass along with the ball. If the only nerve damaged is the recurrent branch of the median nerve, she would lose what movement of the thumb?

Answer 44

Opposition!! This would result in thenar nerve damage!