Week 2 Task Sheet - Wrist Fractures

Question 1

What is the radiocarpal joint?

Answer 1

synovial, ellipsoid, complex, biaxial joint

Between distal end of radius, interarticular disc and scaphoid, lunate and triquetrum

Question 2

What is the midcarpal joint?

Answer 2

synovial plane joints
Divided into three parts:
- LATERAL - trapezium and trapezoid with distal scaphoid
- CENTRAL - capitate with scaphoid and lunate
- MEDIAL - hamate with lunate and triquetrum

Question 3

What is normal ROM for flexion at RCJ? What is it limited by?

Answer 3

0-90

Limited by dorsal radiocarpal ligament and tension in extensor tendons

Question 4

What is normal ROM for extension at RCJ? What is it limited by?

Answer 4

0-85

Palmar radiocarpal ligament, Palmar ulnocarpal ligament, Tension in the flexor tendons.

Question 5

What is normal ROM for radial deviation at RCJ? What is it limited by?

Answer 5

0-15

Ulnar collateral carpal ligament, Impact of scaphoid tubercle on the radial styloid.

Question 6

What is normal ROM for ulnar deviation at RCJ? What is it limited by?

Answer 6

0-45

Radial collateral carpal ligament

Question 7

What is the contribution of the RCJ and MCJ to wrist flexion?

Answer 7

both joints involved - mainly midcarpal

Question 8

What is the contribution of the RCJ and MCJ to wrist extensio?

Answer 8

both joints involved - mainly radiocarpal

Question 9

What is the contribution of the RCJ and MCJ to wrist radial deviation?

Answer 9

mainly midcarpal - some radiocarpal

Question 10

What is the contribution of the RCJ and MCJ to wrist ulnar deviation?

Answer 10

mainly radiocarpal - some midcarpal

Question 11

What is a colles fracture?

Answer 11

transverse fracture of distal radius - within 2.5cm of RCJ

typical ‘dinner fork’ deformity

Question 12

What displacement occurs in a colles fracture?

Answer 12

posterior and radial displacement of the distal fragment of radius

sometimes with fracture of the ulnar styloid

Question 13

How does a colles fracture occur?

Answer 13

fall onto an outstretched hand

Question 14

What deformity occurs in smiths fracture?

Answer 14

transverse fracture of distal radius - within 2.5cm of RCJ

anterior displacement of the distal fragment of radius

Question 15

Why is a smith’s fracture dangerous?

Answer 15

anterior displacement of the radius can cause damage to the carpal tunnel - flexor tendons and median nerve can be damaged

Question 16

How does a smiths fracture occur?

Answer 16

fall onto a flexed wrist (usually in supination)

Question 17

What structures could be damaged during a colle’s fracture immobilistaion?

Answer 17

• flexor tendon shortening
• extensor tendon lengthening
• damage to ligaments
• inferior radiocarpal and radioulnar joint capsule fibrosis
• damage to the fibrocartilagenous disc

Question 18

What is the effect of immobilsation on muscles?

Answer 18

Atrophy

• sacromeres break down and are reabsorbed
• decreased muscle fibre size
• held in a lengthened/shortened position means remodelling to new length

Question 19

What is the effect of immobilsation on synovial fluid?

Answer 19

Loss of sweep and squeeze mechanism

• increased viscosity of the fluid
• less able to lubricate joint
• less able to provide nutrition to the articular hyaline cartilige

Overall, hyaline cartilige becomes dry and flakey

Question 20

What is the effect of immobilisation on the soft tissues?

Answer 20

Collagen continues to deposit in the healing tissues

• laid down in mis mash pattern
• excessive cross link formation

Leads to:

• loss of extensibility
• increased stiffness
• loss of fibre glide
• decreased ROM

Question 21

What is the effect of immobilsation on ligaments?

Answer 21

Increased cross link formation on haphazard collagen fibres
- leads to decreased extensability and increased sitffness

Ligaments are no longer able to stretch in response to movements and load = increased chances of ligament tears if overloaded

Question 22

What type of fracture healing occurs following a colles fracture?

Answer 22

secondary fracture healing

Question 23

Common complications of a Colle’s fracture?

Answer 23

• non-union
• decreased shoulder ROM from being in a sling
• rupture of EPL
• CRPS
• median nerve damage - due to stretching of median nerve
• carpal tunnel syndrome due to swelling

Question 24

What is the involvement of the scaphoid at CMC movements?

Answer 24

synovial saddle joint between trapezium and 1st MCP

Scaphoid under lies trapezium and so therefore movements of trapezium is linked to movements of the scaphoid

Question 25

What are the normal ROM of the CMCJ

Answer 25

Flexion (0)
Extension (0-50)
Abduction (0-80)
Adduction (0)
Opposition

Question 26

Why might CMCJ movements be reduced in scaphoid fractures?

Answer 26

Thumb fixed in mid abduction in cast because of casting

Restriction of all ROM due to immobilisation

Question 27

What is the main complication of scaphoid fractures and why?

Answer 27

necrosis - because the blood supply to scaphoid splits at the waist - so the blood is supplied distally

results in slow and progressive bony collapse and osteoarthritis

Question 28

What are the boundaries of the anatomical snuffbox?

Answer 28

lateral border - abductor pollucis longus and extensor pollucis brevis

medial border - extensor pollucis longus

floor - scaphoid

Question 29

what pass through the anatomical snuffbox (and could be damaged in scaphoid fracture)?

Answer 29

radial artery
extensor carpi radialis longus tendon
extensor carpi radialis brevis tendon

Question 30

what ADLs may be limited following a colles and scaphoid fracture?

Answer 30

gripping:

• holding drinks/knife nd fork
• holding a pen
• cooking and cleaning
• washing and dressing (buttons)

larger movements:

• pushing up from STS
• pushing open doors