Upper Extremity Flashcards
(24 cards)
How many extensor zones are there in the hand? Draw them
8 zones
Zone 3 over PIP
Zone 5 over MCP
Zone 7 over carparl
Zone 8 radius/ulna with carpals
How many extensor zones does the thumb have? Draw them or describe key locations
5
Zone T1 IP jt
zone T3 MCP joint
T5 CMC joint
Which extensor zone injuries should not be repaired in the ED?
7 and 8
zone 5 if bite wound
zone 3 if joint capsule penetrated
Describe Elson’s test for central slip injury
- Place hand over table ende with PIP joint on edge.
- Ask pt to extend PIP jt. If central slip is intact they will extend the joint at the DIP joint will be loose (b/c lateral bands have not been recruited)
- If the central slip is injured, they may still extend the PIP joint but the DIP joint will be stiff and hyperextended due to lateral band recruitment
4 cardinal signs of tenosynovitis:
- Tenderness along tendon sheath
- Fusiform swelling
- Pain with passive extension
- Flexed posture of finger
Which carpal bones are at increased risk for AVN and why?
- Scaphoid, capitate, lunate
- Because they receive blood supply from single distal artery.
(most carpal bones receive distal to proximal blood supply)
- Because they receive blood supply from single distal artery.
What are the normal features of a wrist PA?
- Radial length: 9-12mm
- Radial inclination: 15-25 degrees
Volar tilt 10-25 degrees- Distance between carpal bones: 1mm
- 3 smooth lines drawn along carpal articular surfaces: carpal, or Gulia’s arcs.
What are the normal features of a wrist lateral?
- Volar tilt: 10-25 degrees
- Long axis of radius, lunate, capitate, 3rd metacarpal should appear as straight line with 10 degrees
- Scapholunate angle: 30-60 degrees
- Capitolunate angle: 0-30 degrees
Describe the stages of carpal bone instability and their associated radiographic findings:
· Stage I: Scapholunate dissociation
o PA: widening >2mm scapholunate space “Terry Thomas sign”
o If scaphoid is subluxed/rotated, will also see cortex of distal pole end on as “signet ring sign”
o Stress views if clinically concerned with normal XR à clenched fist in ulner deviation, gap >3mm is suggestive of disruption.
- Stage II: Perilunate dislocation
o Lateral: lunate remains articulated to distal radius, capitate dorsally dislocated
o PA: overlap of distal & proximal carpal rows
o Associated #’s: scaphoid mc, radial styloid, capitate - Stage III: associated triquetral dislocation
o Radiographically as stage II
o PA: Triquetral dislocation seen as overlap of tiquetrum on lunate or hamate - Stage IV: Lunate dislocation
o PA: triangular appearance of lunate (by rotaion in volar direction) “piece of pie sign”
Lateral: lunate volarly displaced “spilled tea cup sign” with dorsal displacement capitate, and lunate no longer articulating with distal radius
List 4 criteria for reduction of colle’s type fracture:
- > 20 degrees angulation
- Intra-articular involvement
- Marked comminution
- > 1cm shortening
What is an acceptable post reduction?
- Neutral or volar tilt
- Radial inclination >11 degrees
- Radial height >11mm
List causes of carpel tunnel syndrome.
- Distal radius fracture
- Repetitive strain
- RA
- Hypothyroidism
- DM
- Renal failure
- Amyloid
- Acromegaly
- Collagen vascular disease
- Pregnancy
- Menopause
- Obesity
List four important ligamentous structures of the elbow.
- Annular ligament
- Radial collateral ligament
- Ulnar collateral ligament
Anterior capsule
Which nerve is most at risk by humeral shaft fractures?
- Radial (20%) à closely associated with the humerus
Most are neuropraxia
List 7 indications for ORIF for humeral shaft fractures.
- Open fractures
- Multiple injuries precluding mobilization
- Bilateral fractures
- Poor reduction
- Poor patient compliance
- Failure of closed treatment
- Pathologic fractures
Radial nerve palsy developing after manipulation
What suggests Septic olecranon bursitis?
- Rapid onset
- Hot red tender bursa
- Limited flexion
- Fever
- Adenopathy
Wounds or abrasions
If septic bursitis is suspected what is the diagnostic test?
- Aspiration (Cell count, gram stain, and culture)
- Traumatic / non septic = leuk count
What is the treatment of septic olecranon bursitis?
- Aspiration
- Antibiotics
- I and D (if resistant to aspiration and ABx) controversial as it is associated with recurrence of bursitis
List indications for immediate and urgent orthopedic referral for operative management of clavicle fractures.
Immediate - Open fractures - Associated neurovascular injuries - Skin tenting Interpositioning of soft tissues
Urgent
- Type II lateral fractures (30% nonunion)
- Severely comminuted or displaced middle third with >20mm shortening (20% malunion)
- Medial third >2cm overlap
How long are clavicle fractures immobilized?
- Children: 2 – 4 weeks
- Adolescents and adults: 4 – 8 weeks
- Full non-painful ROM and absence of pain are good indicators of healing
What are the three types of clavicle fractures.
Medial third (5%) Assoc with PTX and pulm injury
Middle third (80%)
Lateral third (15%)
- Type I: Lateral to CC ligaments, stable
- Type II: Medial to CC ligaments, 30% malunion
Type III: Articular surface
What injuries are associated with scapulothoracic dissociation?
- Severe soft tissue injury
- Brachial plexus injury
Subclavian artery disruption
- Brachial plexus injury
List indications for involvement of an orthopedic surgeon in proximal humerus fractures.
- ≥ Neer 2 part displaced fractures (>1cm and >45 degrees)
Fracture dislocations à closed reduction often not successful
Which of anterior or posterior sternoclavicular dislocations is more concerning?
Posterior – 30% associated mediastinal injuries and airway compromise. May present with hoarseness, dysphagia, dyspnea, weakness or parasthesia of contralateral upper extremity
