Orthopaedic emergencies Flashcards
What are the normal pressures in a compartment? What is too high?
- Usually 0-10mmHg
- Capillaries affected >20mmHg
- Ischaemic necrosis of muscles and nerve fibres >30mmHg
- Higher DBP and MAP can overcome high compartment pressures
Delta pressure = DBP - compartment pressure
Compartment syndrome generally diagnosed if pressure >30mmHg or within 30mmHg of the MAP
What are the most common sites of septic arthritis in adults and children?
Hips in children
Knees in adults
What is the most common primary bone tumour in children and adolescents?
Osteosarcomas
How does the workup of potential orthopaedic prosthesis infection differ from typical septic arthritis?
- Gram stain is only 20% sensitive but is 95% specific
- WCC/ESR/CRP have very low sens/spec and have questionable clinical significance in workup
- Ideally aspiration should not be done in ED unlike septic arthritis
- Cut off for aspirate is >17’000 WCC or >65% Neutrophils (95/90 sens/spec) which is much lower than typical septic arthritis
What is the most common organism causing prosthetic joint infections?
Staphylococcus epidermidis (coagulase negative) 35%
Staph aureus 2nd at 20%
What is the most common organism causing Osteomyelitis across all age groups?
Staph aureus (80%)
Group B strep osteomyelitis is unique to neonates
How does osteomyelitis vary with age?
Long bones are most commonly affected in children
Lumbosacral and thoracolumbar in the elderly
Active UTIs and Urological procedures increase the risk of spinal osteomyelitis
What patient factors impair assessment of distal limb neurovascular status?
Obesity
oedema
Shock
PVD
Peripheral neuropathy
Alterered mental status
unco-operative
Social/language barrier
Distracting injury
Spinal pathology (MS, paraplegia)
What are the features of compartment syndrome?
Main
- Disproportionate pain
- Tight/tender compartment
- Pain on passive stretch
Others
- Pallor, paralysis, paraesthesia and pulselessness
What are the signs of an arterial injury?
- Diminished peripheral pulses + cap refill + cold/pallor
- Pulsatile bleeding
- Expanding/pulsatile haematoma
- Palpable thrill over vessel
- Audible bruit over vessel
What are the clinical features of the two main forms of hip dislocation?
What conditions predispose to septic arthritis in a joint?
Existing joint pathology
- RA, OA, gout
Concurrent long bone osteomyelitis
Immunosuppression
- ie DM, chemo
Penetrating injury to joint
Instrumentation of joint
- Knee arthroscopy etc
What are the potential complications of open fractures?
- Infection
- Neurovascular injury
- Compartment syndrome
- Malunion of bones
- Complex regional pain syndrome
What are the most common types of Distal Radius fractures?
Colles Fracture
- Most common
- Dorsal angulation, extrarticular
- Risk of dinner fork deformity and median nerve injury
Smith Fracture
- Volar angulation, extrarticular, opposite to a Colles fracure
- Risk of carpal bone fracture, carpal dislocation and radial nerve injury
Barton Fracture
- Intra-articular fracture involving the radial rim
- Usually associated dislocation of the radiocarpal joint
Chauffeur Fracture
- Intra-articular fracture involving the radial styloid
- Unstable, needs surgery
- Associated with scapholunate dislocation and injury
Conservative treatment predictors
- Extra-articular
- Radial shortening <5mm
- Dorsal angulation <5 degrees or <20 degrees of the contralateral side
Extensor policis longus tendon rupture is a cmplication common to all distal radius fractures
What factors influence the decision to relocate a joint in the ED vs in theatre?
- Prolonged dislocation (ie days to weeks)
- Significant co-morbidities making ED sedation unsafe
- PHx of difficult/failed relocation
- Not fasted
- Patient preference/refusal
- Orthopaedics want to do in theatre
- Neurovascular compromise
- Known difficult airway or other significant anaesthetic risks
- Associated fractures
- Capacity of ED department (skill mix, staffing, overnight etc)
