Wrist & Hand Flashcards
Remind yourself of the bony anatomy of the wrist
Which bones contribute to the wrist joint?
- Radius
- Carpal ones: scaphoid, lumate, triquetrum
- Articular disc
*REMEMER: ulna does not contribute to wrist joint as it is separated from articulation with carpal bones by fibrocartilaginous ligament called articular disc
State the 4 ligaments of the wrist joint that you need to be aware of; for each state:
- Where they are found in relation to wrist joint
- Where they run from and to
- Role
-
Palmar radiocarpal
- Palmar side
- Radius to both rows of carpal bones
- Stability & ensure hand follows forearm in supination
-
Dorsal radiocarpal
- Dorsum side
- Radius to both rows of carpal bones
- Stability & ensure hand follows forearm in pronation
-
Ulnar collateral
- Medial side
- Ulnar styloid process ot triquetrum & pisiform
- Prevents excess lateral deviation of hand
-
Radial collateral
- Lateral side
- Radial styloid process to scaphoid & triquetrum
- Prevent excessive medial deviation of hand
Remind yourself of blood supply to wrist
The wrist joint receives blood from branches of the dorsal and palmar carpal arches, which are derived from the ulnar and radial arteries
What is meant by a distal radial fracture?
Fracture through the radial metaphysis with or without articular involvement
What are the names of the three most common types of radial fracture?
- Colle’s fracture
- Smith’s fracture
- Barton’s fracture
What is the typical mechanism of injury for #distal radius?
What is a Colle’s fracture, include:
- Intra- or extra- articular
- Angulation
- Specific MOI
- Appearance
- Extra-articular fracture of distal radius with dorsal angulation & dorsal displacement within 2cm of articular surface. *By definition also includes an avulsion fracture of ulnar styloid however this isn’t always present in fractres that are described as ‘Colle’s fractures’
- Fall forwards with outstretched hand in front; forces wrist into supination
- Dinner fork deformity
What is a Smith’s fracture, include:
- Intra- or extra- articular
- Angulation
- Specific MOI
- Appearance
- Extra-articular fracture of distal radius with volar (palmar) angulation with or without volar displacement
- Falling backwards and putting hand out behind body; forcing wrist into prontation
- Garden fork
Summarises mechanism of injury for Colle’s fracture & Smith’s fracture
What is a Barton’s fracture?
- Intrarticular fracture of distal radius with associated dislocation of radio-carpal joint
- Can be volar (more common) or dorsal
Describe the typical presentation of distal radius fractures
- History of trauma
- Immediate pain
- Deformity
- Swelling
- Neurological dysfunction e.g. parasthesia or weakness
What can you ask pt to do to test the motor function of the following nerves in their hand:
- Median nerve
- Ulnar nerve
- Radial nerve
- Median nerve: abduction of thumb
- Ulnar nerve: adduction of thumb
- Radial nerve: extension of IPJ of thumb
What investigations are required for a suspected distal radius fracture?
- Plain radiograph (AP, lateral, oblique)
- ?CT or MRI for complex fractures
What 4 measurements on plain radiograph can help with diagnosis of distal radius fracture?
State the normal measurements for these
- Radial height 10-12mm
- Radial inclination 20-23 degrees
- Radial (volar) tilt 11-12 degrees
- Ulnar variance 0 to -2 mm
*Think rule of 11s
How do you measure the following:
- Radial height
- Radial inclination
- Radial (volar) tilt
- Radial height- C: draw line at level of ulnar aspect of articular surface and on radial styloid. Distance between these. AP VIEW.
- Radial inclination- B: draw line on articular surface of radius at level of ulnar aspect of distal radius then draw a tangent from radial styloid. AP VIEW
- Radial (volar tilt)- A: draw line perpendicular to long axis of radius then draw line along slope of dorsal to volar surface. LATERAL VIEW.
- Ulnar variation: draw 1 lineat level of articular surface of ulna, perpendicular to ulnar shaft. Draw second line at level of lnate fossa of radisu, perpendicular to radial shift. Distance between.
Discuss the management of distal radius fractures
- Closed reduction (under analgesia- commonly haematoma block) then put in below-elbow backslab cast
- Repeat x-ray in 1 week to check for displacement
- If no displacement, apply full cast and then physiotherapy
- If significantly displaced or unstable will require surgical intervention
- ORIF with plating or K-wire fixation
- Cast for a few weeks to ensure immbolisation
State some potential complications of distal radius fractures
- Malunion leading to reduced motion & pain
- Median nerve compression (more common if malunion)
- OA
What is the typical mechanism of injury for scaphoid fractures?
High energy injuries- typically in men aged 20-30. FOOSH with forced dorsiflexion
Describe the blood supply to the scaphoid
- Supplied by branches of radial artery
- Dorsal radial artery supplies 80% of blood
- Retrograde blood flow therefore fratures can compromise blood supply so risk of AVN
- The more proximal the scaphoid fracture, the higher the risk of AVN
What investigations should you do in suspected scaphoid fractures?
- Plain radiograph “scaphoid series” (AP, lateral & oblique)
- *NOTE: scaphoid fractures not always detected on initial radiographs so if still have clinical suspicion immoblise wrist in thumb splint and redo x-ray in 10-14 days. If stil unsure treat as fracture and organise MRI of wrist*
Discuss the management of scaphoid fractures, include:
- Undisplaced
- Undisplaced proximal
- Displaced
- Undisplaced: immobilisation with thumb spica splint
- Undisplaced proxmial: high risk of AVN therefore surgical treatment indicated- especially if in dominant hand
- Displaced: ORIF with screw
Describe the typical presentation of carpal tunnel syndrome
- Pain, numbness, parasthesia in median nerve sensory distribution (NOTE: palm often spared)
- Symptoms worse at night
- Symptoms relieved by handing arm over side of bed or shaking
- Weakness of thumb abduction & wasting of thenar eminence
- Positive Tinel’s test or positive Phalen’s test
What is Dupuytren’s contracture?
Describe the progression of the disease
Benign thickening and contraction of the longitudinal palmar fascia. Disease progression:
- Pitting & thickeninig of palmar skin and underlying subcutaneous tissue
- Painless nodule forms- increase in size
- Cord develops
- Cord contracts over time and pulls on MCP and PIP leading to progressive flexion deformity in fingers
Describe the typical presentation of dupuytrene’s contracture
- Nodular defomrity
- Cords/thickened band
- Reduced range of motion or complete loss of movement
- Ring and little finger most commonly affected
- Positive Hueston’s test (can’t lie hand flat on table)
What is De Quervain’s tenosynovitis?
Inflammation of tendons within the first extensor compartment of the wrist (therefore inflammation of tendons of extensor pollicis brevis & abductor pollicis longus)
Describe the typical presentation of De Quervain’s tenosynovitis
- Pain near base of thumb
- Difficulty with grapsing or pinching
- Swelling near bae of thumb
- Palpable thickening base of thumb area
- Finkelstein’s test positive
What is trigger finger?
- Also called stenosing flexor tenosynovitis
- Finger or thumb click or lock when in flexion preventing return to extension
Explain the pathophysiology of trigger finger
- Repetitive movements can lead to inflammation of tendon and sheath (flexor tenosynovitis)
- Localised nodes form distal to the pulley
- When fingers are flexed, node moves proximal to the pulley
- But then when pt attemptsto extend the digit the node fails to as sunder the pulley so finger becomes locked in flexed position
- A1 pulley most commonly affected
