17 - T&O Wrist and Hand Flashcards
What is the pathophysiology of distal radius fractures?
Fracture of the distal metaphysis of the radius with/without articular involvement
Usually due to FOOSH as distal radius takes 80% of axial load and impaction from supinated/pronated lunnate and scaphoid
- Usually fragility fractures due to osteoporosis or aged 5-15 years
What are the different classifications of distal radial fractures?
Colles’
- Extra articular fracture with dorsal angulation and dorsal displacement, within 2cm of articular surface
- Due to FOOSH and often fragility fracture
- Often cause ulnar styloid avulsion fracture
Smith’s
- Extra articular fracture with volar angulation with/without volar displacement
- Often due to falling backward and planting hand behind the body
Barton’s
- Intrarticular fracture of the distal radius with associated dislocation of the radio-carpal joint
- Can be volar (more common) or dorsal
What are the risk factors for a distal radius fracture?
Factors related to osteoporosis
How does a distal radius fracture present and what are some differentials?
- Immediate pain, deformity and swelling around fracture site
- Need to assess neurovascular compromise (nerve function, cap refill, pulses) and joint above and below for any injuries
- Differentials: forearm fracture (Galeazzi and Monteggia), carpal bone fractures, tendonitis, wrist dislocation
How are distal radius fractures investigated?
Plain radiographs with the following measurements means distal radius fracture:
- Radial height <11mm
- Radial inclination <22 degrees
- Radial (volar) tilt >11 degrees
Can do CT or MRI for operative planning
How are distal radial fractures managed?
- Resuscitate and stabilise
- Closed reduction in A+E by traction and manipulation under anaesthesia (haematoma block or Bier’s block)
- Below-elbow back slab and repeat radiographs in a week to check for displacement
- If no displacement just physiotherapy
- If displacement surgical management (see image)
What are the complications of distal radius fractures?
- Malunion (shortened radius causes reduced wrist motion, wrist pain and reduced forearm rotation. Treat with osteotomy)
- Median nerve compression/Carpal tunnel syndrome
- OA
- EPL rupture
What is the pathophysiology of why a scaphoid fracture results in avascular necrosis?
Usually in men aged 20-30 due to high energy injury
- Scaphoid has proximal pole, waist and distal pole
- Branch of radial artery enters in distal pole and travels in retrograde fashion to proximal pole
- More proximal scaphoid fracture more risk of AVN
How does a scaphoid fracture present and what are some differentials?
- After high energy trauma sudden onset wrist pain
- Tenderness in floor of anatomical snuffbox
- Pain on palpating scaphoid tubercle
- Pain on telescoping the thumb
Differentials: distal radial fracture, alternative carpal fracture, fracture of base of 1st MC, ulnar collateral ligament injury, wrist sprain, De Quervains Tenosynovitis
How are scaphoid fractures investigated, diagnosed and managed?
Ix
- Scaphoid series of plain radiographs (AP, Lateral Oblique)
- If negative initial imaging but high clinical suspicion immobilise wrist in thumb splint for 10-14 days then repeat radiographs
- If still negative imaging but clinical findings still there do MRI
Mx
- If undisplaced strict immobilisation in plaster with thumb spica splint.
- If undisplaced in proximal pole high risk of AVN so surgery particularly if patient’s dominant hand
- All displaced fixed surgically with percutaneous variable pitched-screw
What are some complications with scaphoid fractures?
- AVN (risk increasing with more proximal fractures)
- Non-union (due to poor blood supply)
Can fix above with internal fixation and bone grafts but still do not fix the cause
What is the normal volar tilt and inclination of the distal radial articular surface?
Volar tilt: 10 to 25 degrees
Inclination: 23 degrees (13 to 30)
How do you measure volar tilt and radial inclincation of the distal radius?
Volar tilt: on the lateral projection of the wrist as an angle of the distal radial surface with respect to a line perpendicular to the shaft
Radial inclination: is measured by drawing a line perpendicular to the long axis of the radius and a tangential line from the radial styloid to the ulnar corner of the lunate fossa
What are some risk factors for carpal tunnel syndrome?
Compression of the medial nerve at the carpal tunnel so pain, numbness and paraesthesia of lateral 3.5 digits
More common in women aged 45-60
Risk Factors: female, increasing age, pregnancy, previous injury to wrist, diabetes, RA, hypothyroidism, repetitve hand movements
How does carpal tunnel syndrome present and what might you find on examination?
- Pain, numbness and paraesthesia in median nerve sensory distribution with palmar sparing as palmar cutaneous branch comes off before carpal tunnel
- Symptoms worse during night and relieved by shaking or hanging wrist over edge of bed
- On examination in early stages reproduction of sensory symptoms by Tinel’s and Phalen’s test
- In late stages weakness of thumb abduction wasting of thenar muscles due to denervation
What are some differential diagnoses for carpal tunnel syndrome?
- Cervical radiculopathy C6 (however will have neck pain and entire arm affected)
- Pronator teres syndrome (median nerve compressed by PT, symptoms will extend into forearm and affect palm)
- Flexor Carpi Radialis Tenosynovitis (tenderness at base of thumb)
How is carpal tunnel syndrome investigated and managed?
Ix
- Usually clinical diagnosis but can do nerve conduction studies to confirm median nerve damage
Mx
Conservative: wear wrist splint at night, physiotherapy, corticosteroid injections
Surgical: carpal tunnel release surgery by cutting through flexor retinaculum to reduce pressure on median nerve, can be done under local
What is the pathophysiology of Dupuytren’s contracture?
- Contraction of longitudinal palmar fascia
- Starts as painless nodules and fibrous cords at MCP and interphalangeal joints eventually leading to contraction
What are some risk factors for developing Dupuytren’s contracture?
- Smoking
- Alcoholic liver cirrhosis
- Diabetes mellitus
- Heavy manual work/vibration
- Idiopathic
How does Dupuytren’s contracture present and what are some differentials?
- Thickened band or firm nodule adherant to skin may be palpable
- Skin blanching may occur on extension of digits
- Ring and little finger often involved
- Hueston’s palm table top test
Differentials: stenosing tenosynovitis, ulnar nerve palsy, trigger finger (nodules associated with finger motion)
How is Dupuytren’s contracture managed once a clinical diagnosis is made?
Conservative (early stages):
- Hand therapy, injectable collagenase clostridum histolyticum
Surgical (if functional impairment, MCP joint contracture >30 degrees, PIP contracture or rapidly progressive disease):
- Removal of diseased fascia called a fasciectomy
What is De Quervain’s Tenosynovitis and what are some risk factors for this?
Inflammation of the tendons in the first extensor compartment (EPB and APL) of the wrist resulting in wrist pain and swelling
Risk factors: female, age 30-50, pregnancy, occupations or hobbies involving repetitive movements of the hands
How does De Quervian’s tenosynovitis present on examination?
- Pain near the base of the thumb
- Grasping or pinching movements painful and difficult
- Swelling and palpable thickened over tendon group
- Positive Finkelstein test
What are some differentials for De Quervian’s Tenosynovitis?
How is De Quervian’s tenosynovitis investigated and managed?
Ix: clinical diagnosis but can use plain hand radiograph to exclude differentials (e.g arthritis)
Mx:
Conservative: avoid repetitive actions, wrist splint, steroid injections
Surgical: decompression of extensor compartment by incising tendon sheath and allows tunnel roof to form again but heals wider. Can caused reduced ROM, neuroma fromation and nerve impingement.
What is the pathophysiology of ganglionic cysts and what are some risk factors for developing these?
Degeneration within joint capsure or tendon sheath that becomes filled with synovial fluid froming soft tissue lump
Often in dorsal wrist of females aged 20-40
Risk factors: female, previous joint or tendon injury, OA (due to increased fluid in joint)
How do ganglionic cysts present and what are some differentials?
- Smooth painless lump that transilluminates.
- Lump may restrict ROM
- If putting pressure on adjacetn nerves can cause localised paraesthesia, pain or motor weakness
How are ganglionic cysts investigated and managed?
Ix
- Diagnosis often clinical
- Plain film radiograph can rule out differentials
- If uncertain can US or MRI
Mx
- Often resolve spontaneously so monitor unless pain or severely limits ROM then…
- Can aspirate and steroid injection but high rate of recurrence
- Cyst excision including capsule and part of tendon sheath if above fails
What is the pathophysiology of trigger finger?
Finger or thumb click/lock when in flexion preventing a return to extension
Usually some flexor tenosynovitis and if at metacarpal head there is localised nodal formation on the tendon distal to A1 pulley
When fingers are flexed the node moves proximal to the pulley but when trying to extend the node fails to pass back under the pulley so digit becomes locked in flexion
What are some risk factors for trigger finger?
- Occupation or hobby involving prolonged gripping and use of hand
- RA
- Diabetes
- Female
- Increasing age
- Amyloidosis
How does trigger finger present and what are some differential diagnoses?
- Painless clicking/snapping when trying to extend finger (usually middle or ring)
- Can become painful over time
How is trigger finger invesigated and managed?
Ix
Clinical diagnosis
Mx
Conservative: splint to hold finger in extension at night, steroid injections
Surgical (if no improvement with above): percutaneous trigger finger release under local, if severe case can do surgical decompression of tendon tunnel
How would you perform an hand exam in an OSCE?
- Look (nails, elbows, scars, palms)
- Feel
- Move (test FDP and FDS separately)
- Function
- Special tests
How do you test motor function in the hand?
Radial: wrist extension (commonly injured in axilla, humeral shaft fracture, iatrogenic)
Ulnar: finger abduction and Froment’s sign (commonly injured in cubital tunnel)
Median: thumb abduction
