Ortho OSCE Topics Flashcards
Which 4 areas are often affected by compartment syndrome?
Elbow (supracondylar #) Forearm bones (proximal) Proximal 1/3 of the tibia Foot Scapula
Name causes of compartment syndrome
Intracompartmental
- fracture
- reperfusion injury
- crush injury
- ischemia
Extracompartmental
- constrictive dressing
- poor position during surgery
- circumferential burn
How is compartment syndrome diagnosed?
1st sign = paraesthesia 2nd = pain out of proportion 3rd = pain on passive stretch Woody, hard swelling of the compartment Suspicious history
How does compartment syndrome result in paraesthesia?
Compression of the small aa that supply the nerve
What is pain out of proportion?
Not resolving after splinting Adequate analgesia (morphine, tramadol, perfalgan)
How do you test pain on passive stretch in the lower limb?
Flex the big toe
Which compartment is first affected in the lower limb?
Anterior compartment
How do you test pain on passive stretch in the upper limb?
Extension of the fingers
Which compartment is usually affected in compartment syndrome of the upper limb?
Flexor compartment
Name the classic features of compartment syndrome
- Paraesthesia
- Pain out of proportion
- Pain on passive stretch
- Pallor
- Paralysis
- Pulselessness
What investigations do you do in compartment syndrome?
It is a clinical diagnosis therefore investigations are usually not necessary
How do you diagnose children or unconscious patients with compartment syndrome as clinical exam is unreliable?
Compartment pressure monitoring with catheter
What is the normal compartment pressure?
0mmHg
What compartment pressure suggests compartment syndrome?
Pressure >30mmHg
OR
DBP - pressure <30mmHg
Discuss the non-operative management of compartment syndrome
Decompress threatened compartments - cut casts, bandages, dressing - split the splint bandages to keep fracture stable - cut circular POP on both sides Keep limb at the level of the heart Wait 20-35min and repeat examination - improvement = continue - no improvement = fasciotomy
Why should you keep the limb at the level of the heart in compartment syndrome?
Decreases end capillary pressure which aggravates the muscle ischemia
Discuss operative management of compartment syndrome
Surgically open the compartment
Leave the wound open and inspect 48-72h later
If muscle necrosis -> debridement
If healthy tissues -> suture wound without tension or use skin graft
How do you do a fasciotomy of the leg?
Open all 4 compartments through medial and lateral incisions
How long does it take for muscle necrosis to occur?
4-6h of total ischemia
Name complications of compartment syndrome
Volkmann’s ischemic contracture
Rhabdomyolysis
Renal failure secondary to myoglobinuria
Define an open fracture
Fractured bone and hematoma in communication with the external/contaminated environment
Discuss the acute management of open fractures
- ABCs
Primary survey
Resus - Control bleeding with direct pressure
- Remove obvious foreign material
- Irrigate with normal saline if grossly contaminated
- Cover wound with saline soaked sterile dressings
- IV antibiotics once diagnosis of open fracture is confirmed
- coamoxiclav
- cefuroxime
- clindamycin - Tetanus toxoid if previously immunized
Tetanus immunoglobulin if not previously immunized - Reduce bone/joint
- Splint the limb until surgery
- NPO and preparation for theater
- bloods
- consent
- ECG
- CXR - Monitor state of soft tissues and neurovascular supply
What are the 4 essentials of open fracture care?
Antibiotic prophylaxis
Prompt wound debridement
Fracture stabilization
Early definitive wound cover
How are open fractures classified?
Gustilo Anderson classification
Discuss the Gustilo Anderson classification
Grade I - <1cm long - minimal soft tissue injury - simple, low-energy fracture Grade II - >1cm long - moderate soft tissue injury w/ some mm damage - moderate comminution Grade IIIA - >1cm long - extensive soft tissue injury with adequate ability of soft tissue to cover wound - high-energy fracture, comminuted Grade IIIB - >10cm long - severe loss of soft tissue cover Grade IIIC - >10cm long - severe loss of soft tissue cover with vascular injury
Which antibiotic do you give for a Gustilo Anderson grade I and II?
- 1st gen cephalosporin (cefazolin) 2g IV q8h 2d
- Allergy = clindamycin 900mg IV tds
- MRSA + = vancomycin 15mg/kg IV bd
Which antibiotic do you give for a Gustilo Anderson III?
- 1st gen cephalosporin (cefazolin) 2g IV q8h 2d plus gentamicin/ceftriaxone for 3d
- Metronidazole w/wo penicillin G for soil/fecal contamination
- MRSA + = vancomycin 15mg/kg IV bd
Discuss the post-acute management of open fractures
Operative irrigation and debridement within 6-8h and repeat 24-48h until wound viable External fixation Wound dressing - vac - antibiotic bead pouch Delayed wound closure within 3-7d
Define osteomyelitis
Bone infection with progressive inflammatory destruction
What is the most common mechanism of paediatric osteomyelitis?
Hematogenous seeding of bacteria to metaphyseal region of bone
How do you diagnose acute hematogenous osteomyelitis?
Kocher criteria
Discuss the Kocher criteria
- Non-weight bearing on affected side
- ESR>40mm/hr
- Fever
- WBC>12000
Probability: 4/4 = 99% 3/4 = 93% 2/4 = 40% 1/4 = 3%
How does acute haematogenous osteomyelitis present clinically?
Non-weight bearing on affected side
Fever
Bone tenderness on palpation
What investigations should you perform in acute hematogenous osteomyelitis?
XR to exclude fractures Bloods - ESR - CRP - WCC
How do you manage acute hematogenous osteomyelitis?
Refer to orthopaedics
No antibiotics
Drain pus
Send pus for MCS
How do you manage acute hematogenous osteomyelitis?
Refer to orthopaedics
No antibiotics
Drain pus
Send pus for MCS
Why do we not give antibiotics in acute osteomyelitis?
Patient is presenting with clinical signs therefore past bone oedema phase and in abscess phase, therefore manage as an abscess
What is the most common organism involved in acute osteomyelitis?
Staph aureus
Name risk factors for acute osteomyelitis
Recent trauma Recent surgery Immunocompromised Haemoglobinopathy RA Chronic renal disease IV drug use Microvascular disease Peripheral neuropathy
What are the mechanisms of acute osteomyelitis spread?
Haematogenous
Direct inoculation
Contiguous focus
Name XR findings in osteomyelitis
Early - normal - loss of soft tissue planes - soft tissue oedema - new periosteal bone formation 5-7d - osteolysis 10-14d Late - metaphysical rarefaction - abscess - mottled, non-homogenous, moth eaten appearance
What occurs in chronic osteomyelitis after the area of bone has been destroyed by acute infection?
Sequestra surrounded by dense sclerosed bone which provoke chronic seropurulent discharge which escape through sinus at the skin surface
Define sequestrum
Dead bone
How does sequestrum appear on XR?
Sclerotic (more white)
Define involucrum
New bone formation around dead bone to protect the bone from breaking
Define a sinus
A hole in the skin draining fluid
What is a “sinus” in the bone cortex called?
Cloaca
Define a fracture
A break in the continuity of the bone cortex
Name the red flags of back pain
BACK PAIN Bowel/bladder dysfunction Anesthesia (saddle paresthesia) Constitutional symptoms Khronic disease Paresthesias Age >50yo or <15yo IV drug use Neuromotor deficits
Other: Weight loss Pain at night, while sleeping, at rest Morning stiffness Sensory loss Fever Cancer history Hypercalcemia
What questions should be asked on history in back pain?
SOCRATES
Site Onset Characteristics Radiation Associated symptoms Time Exacerbating/relieving factors Severity
Define wrist drop
Inability to extend the wrist and the fingers at the metacarpophalangeal joints
Which nerve is affected in wrist drop?
Radial nerve (high lesion)
Name causes of high lesions of the radial nerve
Humeral fracture
Prolonged tourniquet
Saturday night palsy
Which muscles are affected in wrist drop?
Wrist extensors
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor carpi ulnaris
- Extensor digitorum
- Extensor digiti minimi
Which nerve is affected in foot drop?
Common peroneal/fibular nerve
Define foot drop
Weak dorsiflexion and eversion of the foot resulting in tendency to trip and fall while walking
Which muscles are affected in foot drop?
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Fibularis tertius
Name mechanisms of injury of the axillary nerve
Proximal humerus fracture
Humeral neck fracture
Shoulder dislocation
How do you examine the motor function of the axillary nerve?
Isometric deltoid contraction
Place hand on the lateral side of the injured arm to prevent movement and other hand on the deltoid to feel contraction
How do you examine the sensory function of the axillary nerve?
Numbness over the deltoid
Difficult to test due to pain
Name mechanisms of injury to the radial nerve
Very high lesion - crutch palsy High lesion - humeral fracture - prolonged tourniquet pressure - Saturday night palsy Low lesion - elbow fracture - elbow dislocation
How do you examine the motor function of the radial nerve?
Very high lesion:
Triceps paralyzed and wasted
High lesion:
Wrist extension
Thumbs up
Low lesion:
Metacarpophalangeal joint extension
How do you examine the sensory function of the radial nerve?
Dorsum of the 1st web space
Name mechanisms of injury to the median nerve
High lesion - supracondylar fracture - elbow dislocation Low lesion - carpal dislocation - cuts in the front of the wrist
How do you examine the motor function of the median nerve?
High lesion:
O sign
Index DIP flex for positive benediction sign
Low lesion:
Thumb abduction
What is the purpose of the O sign?
Flexor pollicus and deep flexor of index finger supplied by anterior interosseous nerve
What is the innervation of the abductor pollicis muscle?
Recurrent thenar br of median nerve
Which test for the median nerve is not applicable in a distal radius fracture?
O sign
How do you examine the sensory function of the median nerve?
Pulp of the index finger
Name the mechanisms of injury of the ulnar nerve
High lesion
- elbow fracture
Low lesion
- wrist pressure/laceration
How do you examine the motor function of the ulnar nerve?
On a flat surface, finger abduction and adduction
Froment’s test
How do you examine the sensory function of the ulnar nerve?
Ulnar side of little finger
Explain Froment’s test
Ask patient to hold piece of paper in hands between thumb and index fingers to test adductor pollicis
If test is positive, patient will acutely flex in IPJ of the thumb because flexor pollicis longus is supplied by median nerve
Name the mechanisms of injury of the femoral nerve
Anterior hip dislocation
Gunshot wound
How do you examine the motor function of the femoral nerve?
Knee extension (anterior thigh compartment)
How do you examine the sensory function of the femoral nerve?
Anterior thigh
Medial aspect of leg
Name the mechanisms of injury of the sciatic nerve
Posterior hip dislocation
Hip replacement
How do you examine the motor function of the sciatic nerve?
All muscles below the knee eg foot dorsiflexion
How do you examine the sensory function of the sciatic nerve?
Majority of the leg
Name the mechanisms of injury of the common peroneal nerve
Fibular neck fracture
How do you examine the motor function of the common peroneal nerve?
Foot dorsiflexion
Foot eversion
Drop foot
How do you examine the sensory function of the common peroneal nerve?
Anterolateral half of lower leg
Dorsum of foot
How will an injury to the superficial branch of the common peroneal nerve appear?
Dorsiflexion intact
Loss of sensation over anterolateral lower leg and foot
How will an injury to the deep branch of the common peroneal nerve appear?
Weakness of dorsiflexion
Loss of sensation around 1st web space on dorsum of foot
What nerve is likely injured if a patient is stabbed in the antecubital fossa?
Median nerve
What is Gallow’s traction?
Used in infants/children with femoral fractures
Fractured and healthy femur placed in skin traction and infant suspended from special frame with buttocks just off the bed for 1 week per year of age + 1 week
Start mobilizing at 6w
Name the complications of Gallow’s traction
Vascular compromise
Occipital pressure sore
Aspiration
Compartment syndrome
What is Waddell’s triad?
Femur fracture
Head injury
Thoracic/abdominal injury
When is a Thomas splint used?
For femur fractures with skin/skeletal traction
How do you determine the size of the Thomas splint?
Thigh circumference at groin + 4cm for ring
True limb length + 20cm
How do you calculate the weight of traction with a Thomas splint?
10% of patient’s body weight
Maximal weight = 5kg (skin sloughing)
Name indications for skin traction
Femur fractures
Hip dislocation
Hip fracture-dislocation
What views do you want in a trauma series XR?
- AP chest
- AP pelvis
- Lateral c spine
- AP and lateral of all suspected bones injured
Name complications of bed ridden patients
- Delirium
- Confusion
- Pneumonia
- PE
- Ileus
- Constipation
- Stress ulcers
- UTI
- Pressure sores
- DVT
- Muscle weakness
- Contractures
How do you prevent pneumonia in bed ridden patients?
Physiotherapy
How do you prevent PE in bed ridden patients?
DVT prophylaxis
How do you prevent constipation in bed ridden patients?
High fiber diet
Lactulose
How do you prevent stress ulcers in bed ridden patients?
PPI
H2 receptor antagonists
How do you prevent UTI in bed ridden patients?
Silicon catheter
Treat with antibiotics
How do you prevent pressure sores in bed ridden patients?
Turn 4hrly
Examine pressure points regularly
Ripple bed
How do you prevent DVT in bed ridden patients?
LMWH
Pressure stockings
How do you prevent contractures in bed ridden patients?
Early mobilization
Physiotherapy
What is the peak age of supracondylar fractures?
7yo
Name the mechanisms of supracondylar fractures
96% extension injuries via FOOSH
4% flexion injuries
What is the most common displacement in supracondylar fracture?
Posterior displacement
Name the clinical features of a supracondylar fracture
Pain, swelling, tenderness S-deformity (posterior displacement) Neurovascular injury - radial aa - radial, median, ulnar nn
What on XR will suggest supracondylar fracture?
Disruption of anterior humeral line
Fat pad sign
What is the anterior humeral line?
Line drawn down the anterior surface of the humerus that should intersect the middle third of the capitulum
Indicates supracondylar fracture if not
What is the radiocapitellar line?
Line drawn through center and long axis of the radius that should go through the capitulum
Indicates radial head dislocation if not
Discuss the Gartland classification of supracondylar humeral fractures
Type I
- non-displaced
Type II
- anterior cortex displaced but posterior cortex still in continuity
IIa
- less severe with distal fragment angulated
IIB
- severe with distal fragment angulated and malrotated
Type III
- completely displaced fracture with preserved posterior periosteum
Type IV
- displaced with periosteal disruption, unstable in flexion and extension
Discuss the management of supracondylar humeral fractures
Acute
- gently splint in 30 degrees flexion to prevent movement and neurovascular injury during XR
Non-displaced = non-operative
- long arm plaster backslab in 90 degree flexion for 3w
- XR 5-7d later to ensure no displacement
Operative:
a) Displacement >50%
b) Vascular injury
c) Open fracture
- percutaneous pinning with k wires followed by limb cast with elbow flexed <90 degrees
Name complications specific to supracondylar humeral fracture
Stiffness Brachial artery injury Medial, radial, ulnar nn injury Compartment syndrome Malalignment cubitus varus
What is Dunlop traction used for?
Maintenance of reduction in paediatric supracondylar humeral fractures
When is Dunlop traction contraindicated?
Open fracture
Skin defects
Explain the method of Dunlop traction
Skin traction placed on forearm and elevate 45 degrees over drip stand with 1.5kg weight
Broad sling around upper arm to enable traction along axis of forearm and right angles to humerus
Bed blocks required on lateral side of the bed
What should you do if there is no pulse in a displaced supracondylar humeral fracture?
Pink pulseless hand:
Modified Dunlop
No pulse -> Dunlop
No pulse -> orthopaedics
Cold pulseless hand
Full Dunlop and phone the vascular surgeon
Name the mechanisms of injury of tibial and fibular fractures
- Twisting force causing spiral fracture of both at different levels
- Angulatory force producing transverse/oblique fractures at same level
- Indirect low energy injury causing spiral or long oblique fracture that may pierce the skin
- Direct high energy injury crushes/splints the skin over the fracture
Name clinical features of tibial and fibular fractures
Severe swelling
Bruising
Crushing/tenting of the skin
Neurovascular injury
Discuss the management of tibial and fibular fractures
Closed and minimally displaced
- long leg cast 8-12w w/ functional brace after
Displaced and closed
- ORIF w/ IM nail, plate and screws or EF
Displaced and open
- AB
- I&D
- EF or IM nail
- vascularised coverage of soft tissue defects
Name complications of tibial and fibular fractures
Vascular injury Compartment syndrome Infection Joint stiffness Complex regional pain syndrome
Which vascular supply is endangered by tibial fracture?
Popliteal artery
Where is spinal TB most often found in the spine?
Thoracic spine
What is the most common site of skeletal TB?
Spine
Name clinical features of TB spine
Constitutional symptoms - chronic illness - malaise - night sweats - weight loss Back pain Kyphotic/gibbus deformity Neurological deficit Cervical = dyspnoea, dysphagia Thoracic = pectus carinatum
What are the mechanisms of neurological deficit in TB spine?
- Mechanical pressure on cord by abscess, granulation tissue, tubercular debris, caseous tissue
- Mechanical instability from sublaxation/dislocation
- Stenosis from ligamentum flavum ossification and severe kyphosis
What investigations should you do to diagnose TB spine?
Skin tests (sensitive, non-specific) HIV status ESR WCC XR MRI Needle biopsy
Name the features of spinal TB on XR
Early - local osteoporosis of 2 adjacent vertebrae - loss of crispness of the end plate Late - disk space destruction - collapse of adjacent vertebral bodies - severe kyphosis - paraspinal soft tissue shadows
Give a differential diagnosis for TB spine
Malignancy
Pyogenic infection
Fungal infection
Parasitic infection (hydatid disease)
Discuss the treatment of TB spine
1. Pharmaceutical Full drug treatment for 9-12mo OR Pulmonary strategy: RIPE for 2 months then RI for 9-18 months Resistance - fluoroquinolone - aminoglycoside 2. Surgical - abscess drainage - advanced disease - neurological deficit that has not responded to drug therapy within 8w
Which TB drug is bacteriostatic?
Ethambutol
Name side effects of TB treatment to monitor for?
Hepatitis (isoniazid)
Depression (ethambutol)
Visual acuity (ethambutol)
What is the mnemonic for TB drug side effects?
INH (iron accumulation, neuritis, hepatitis)
Ethambutol = eyes
Rifampin = red
Pyrazinamide = hyperuricemia
What is the main complication in TB spine?
Pott’s paraplegia
- early onset paresis
- late onset paresis
Name early local complications of fractures
Skin - necrosis - fracture blister - open wound Muscle - compartment syndrome Nerve - neuropraxia - axonotmesis - neuronotmesis Vessels - arterial injury Tendon injury Infection
Name early systemic complications of fractures
Hemorrhagic shock FES ARDS SIRS MOFS DVT PE Delirium tremans Pressure sores Tetanus Sepsis
Name late complications of fractures
Delayed union Non-union Malunion Avascular necrosis Growth disturbance Osteoarthritis Joint stiffness CRPS Heterotopic ossification Osteomyelitis
Name fractures that always require surgery
Neck of femur in young patients
Galeazzi
Monteggia
Lower limb in elderly
Name general indications for ORIF
Failure of closed reduction Failure to maintain closed reduction Displaced intra-articular fractures Polytrauma Pathological fracture Non-union Floating elbow/knee
Name sites of intra-articular fractures
Tibial plateau Tibial plafond Intra-articular distal radius Radial head Femoral intercondylar Humeral intercondylar
Which ankle fracture does not recieve ORIF?
Non-displaced lateral malleolus without medial tenderness
What does medial ankle tenderness indicate?
Medial malleolus fracture
OR
Deltoid ligament injury
How are foot fractures generally managed?
Non-operative if non-displaced
Talus ORIF
Calcaneus ORIF
What is the most common malignant tumour type in a patient <10yo?
Ewing’s sarcoma
What is the most common malignant tumour type in a patient 10-20yo?
Osteosarcoma
What is the most common malignant tumour type in a patient >50yo?
Metastases
Which sites does osteosarcoma commonly affect?
Sites of rapid growth
- distal femur
- proximal tibia
- proximal humerus
Name risk factors for osteosarcoma
Paget’s disease
Previous radiation
Name clinical features of osteosarcoma
Progressive pain
Night pain
Poorly defined swelling
Decreased ROM
Name XR findings in osteosarcoma
Variable appearance - hazy osteolytic areas - unusually dense osteoblastic areas Poorly defined margins Sunburst effect Codman's triangle
Discuss the management of osteosarcoma
Multiagent chemotherapy for 8-12w Complete resection w/ limb salvage Neoadjuvant chemotherapy Bone scan CT chest
How do you see if the talus has shifted?
Spaces on all 3 sides (medial, lateral, superior) of the talar dome must be equal
How do we classify ankle fractures?
Denis-Weber
Type A - infrasyndesmotic
Type B - trans-syndesmotic
Type C - suprasyndesmotic
Discuss the management of ankle fractures
Acute - reduction under conscious sedation - below knee backslab Surgical - ORIF
What is a Pott’s fracture?
Name for a variety of bimalleolar fractures
Tibia and fibula splay
Talus goes superior
What are the signs of flexor tenosynovitis?
Kanavel’s signs
- flexed posturing of the involved digit
- tenderness to palpation over tenderness sheath
- marked pain with passive extension of the digit
- fusiform swelling of the digit
Define a dislocation
Joint surfaces are completely displaced and no longer in contact
Define a sublaxation
A lesser degree of displacement such that the articular surface are partially apposed
Define fat embolism syndrome
An inflammatory response to embolized fat globules in the circulation
Give the criteria for fat embolism syndrome
Gurd’s criteria
1 major + 4 minor Major - petechial rash - respiratory involvement - cerebral involvement Minor - tachycardia - pyrexia - retinal changes - anuria/oliguria - thrombocytopenia - anemia - high ESR - fat macroblobinemia
What are the theories of FES aetiology?
- Mechanical obstruction in pulmonary capillaries
2. Free fatty acids directly affecting pneumocytes
Discuss the treatment of FES
Adequate splinting of long bone fractures
O2 administration
Fluids