Week 2 Task Sheet - Wrist Fractures Flashcards
What is the radiocarpal joint?
synovial, ellipsoid, complex, biaxial joint
Between distal end of radius, interarticular disc and scaphoid, lunate and triquetrum
What is the midcarpal joint?
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
What is normal ROM for flexion at RCJ? What is it limited by?
0-90
Limited by dorsal radiocarpal ligament and tension in extensor tendons
What is normal ROM for extension at RCJ? What is it limited by?
0-85
Palmar radiocarpal ligament, Palmar ulnocarpal ligament, Tension in the flexor tendons.
What is normal ROM for radial deviation at RCJ? What is it limited by?
0-15
Ulnar collateral carpal ligament, Impact of scaphoid tubercle on the radial styloid.
What is normal ROM for ulnar deviation at RCJ? What is it limited by?
0-45
Radial collateral carpal ligament
What is the contribution of the RCJ and MCJ to wrist flexion?
both joints involved - mainly midcarpal
What is the contribution of the RCJ and MCJ to wrist extensio?
both joints involved - mainly radiocarpal
What is the contribution of the RCJ and MCJ to wrist radial deviation?
mainly midcarpal - some radiocarpal
What is the contribution of the RCJ and MCJ to wrist ulnar deviation?
mainly radiocarpal - some midcarpal
What is a colles fracture?
transverse fracture of distal radius - within 2.5cm of RCJ
typical ‘dinner fork’ deformity
What displacement occurs in a colles fracture?
posterior and radial displacement of the distal fragment of radius
sometimes with fracture of the ulnar styloid
How does a colles fracture occur?
fall onto an outstretched hand
What deformity occurs in smiths fracture?
transverse fracture of distal radius - within 2.5cm of RCJ
anterior displacement of the distal fragment of radius
Why is a smith’s fracture dangerous?
anterior displacement of the radius can cause damage to the carpal tunnel - flexor tendons and median nerve can be damaged
How does a smiths fracture occur?
fall onto a flexed wrist (usually in supination)
What structures could be damaged during a colle’s fracture immobilistaion?
- flexor tendon shortening
- extensor tendon lengthening
- damage to ligaments
- inferior radiocarpal and radioulnar joint capsule fibrosis
- damage to the fibrocartilagenous disc
What is the effect of immobilsation on muscles?
Atrophy
- sacromeres break down and are reabsorbed
- decreased muscle fibre size
- held in a lengthened/shortened position means remodelling to new length
What is the effect of immobilsation on synovial fluid?
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
What is the effect of immobilisation on the soft tissues?
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
What is the effect of immobilsation on ligaments?
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
What type of fracture healing occurs following a colles fracture?
secondary fracture healing
Common complications of a Colle’s fracture?
- 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
What is the involvement of the scaphoid at CMC movements?
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
What are the normal ROM of the CMCJ
Flexion (0) Extension (0-50) Abduction (0-80) Adduction (0) Opposition
Why might CMCJ movements be reduced in scaphoid fractures?
Thumb fixed in mid abduction in cast because of casting
Restriction of all ROM due to immobilisation
What is the main complication of scaphoid fractures and why?
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
What are the boundaries of the anatomical snuffbox?
lateral border - abductor pollucis longus and extensor pollucis brevis
medial border - extensor pollucis longus
floor - scaphoid
what pass through the anatomical snuffbox (and could be damaged in scaphoid fracture)?
radial artery
extensor carpi radialis longus tendon
extensor carpi radialis brevis tendon
what ADLs may be limited following a colles and scaphoid fracture?
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
