OrthoOverview Flashcards
Second most commonly fractured carpal bone?
Triquetrum!
“Tri”ed but came second
Scaphoid most common
Salter Harris classification
SH 1?
6% of paeds fractures
Transverse # through the growth plate
EASILY reduced if displaced
Often not displaced and no signs of # on XR - clinical diagnosis
SH2?
Most common = 75%
Usually easy to reduce but at risk of slippage
Sometimes can trap periosteum preventing full closed reduction
SH3?
8%
MCQ 🚨 : MOST COMMON SH3 = TILLAUX i.e. distal tibia
Older children i.e. occur in partially closed growth plates so non-union is the problem (growth arrest less so)
Horizontal # through growth plate + vertical through epiphysis
Physeal bar causes difficult reduction
If displaced all need ORIF
SH Type IV?
10%
Most common = lateral condyle of the humerus
Metaphysis, physis and epiphysis all involved
ORIF for almost all
SH Type V?
Rare
Compression
Usually diagnosed retrospectively due to growth arrest - hard to see on XR
Paediatric growth plate is injured in what proprotion of bony injuries?
1/3
Which bones are most prone to avascular necrosis in paediatrics?
Femoral head
Radial head
What is the rate of nerve injury in supracondylar fractures & which is the most commonly injured nerve?
15%
Anterior interosseous = loss of OK sign (Thumb Abduction)
A.I. supplies FDP + FPL
What is the sign of benediction?
Unable to flex the index and middle fingers when making a fist
Anterior interosseous injury
How do you distinguish claw hand from the sign of benediction?
They look really similar
Claw hand = ulnar nerve injury
resulting in fixed flexion deformity of 4/5th PIP and DIPJs
Hand of benediction = Uable to flex 2nd and 3rd so you can actively extend the 4/5th
What is wartenbergs sign versus wartenbergs syndrome?
What does the
“thumbs up” sign test?
Extensor Pollicis Longus
radial n
What does crossing fingers test?
Palmar and dorsal interossei
Ulnar n
What is a gartland I elbow # & how is it managed?
Undisplaced # through distal radius
XR may show sail sign/posterior fat pad
Mx = 90 degree backslab for 3 wks
What is a sail sign?
Anterior fat pad normally hidden within coronoid fossa - elevated and displaced
Pathognomnic of fracture
What is a gartland II fracture
IIA and IIB
Both have intact posterior cortex
BUT
B has rotational deformity (needs OT for MUA +/- ORIF) / coronal plane involvement
Reduction can be attempted in ED if NO coronal plane deformity
What is a Gartland III #?
Grossly displaced distal humeral fracture, no intact cortex
What is a medium-long term complication of Gartland III fractures?
Volkamann ischaemic contracture!
Can also happen to Gartland II that is splinted in <90 degrees
Percentage of Gartland III fractures causing brachial artery injury?
15%
Entrapment/laceration/intimal tear/compartment compression
What does vascular compromise in Gartland require?
Immediate ORIF
Reductions in ED can cause further damage
True or false… Medial condylar fractures are rare in children?
TRUE
Medial (internal ossification centre at age 5)
What is CRITOE?
Age of elbow ossification centres
C - capitellum 1
R - Radial head 3
I - internal epicondyle 5
T - Trochlea 7
O - Olecranon 9
E. - external epicondyle 11
What % of elbow fractures are lateral condyle in paediatrics?
20%
Vasc compromise RARE with lat condyle
What displacement in lateral condyle fractures requires surgery?
> 2mm
<2mm = 90 degree flexion with pronation splinting
Most commonly missed foerarm fracture?
Galeazzi
Distal 1/3 radial fracture with dislocation of the distal radioulnar joint
Which nerves can be damaged in a Galeazzi fracture?
Ulnar
+
Posterior interosseous nerve
What nerves can be injured in a monteggia fracture-dislocation?
Radial
+
Posterior interosseous
(continuation of radial)
What is the classification system for monteggia fracture-dislocation?
BADO:
1 = ant dislocation radial head
2 = post dislocation
3 = lateral
4 = radius and ulna broken
What age is a femoral shaft fracture normal, what is the pattern and mechanism?
<1 = NAI
Toddlers = minimal trauma/twisting
What is a toddlers fracture?
What are the XR findings?
What is the Rx?
Spiral # of tibia
Often no change on XR in 1st week
Long leg cast
What should be done in suspected toddlers fracture without clear Hx of injury?
FBE + inflamm markers
Most commonly affected part of a bone in paediatric osteomyelitis & route of spread?
Metaphysis of long bones
Haematogenous
Both OM and septic arthritis in children most commonly due to haematoegnous spread
Most common bones affected by osteomyelitis in children?
Femur
Tibia
Humerus
Metaphysis usually
Also pelvis/vertebrae
Most common organism in both OM and septic arthritis in kids?
Staph aureus
Peak age of transient synovitis of the hip?
3-8 years old
Differential of transient synovitis?
Septic arthritis
Osteomyelitis
Perthes (peak 4-10)
Malignancy
Juvenile rheumatoid arthritis
Osteoid osteoma
SUFE (age 10-16 years)
What would be a reassuring examination finding consistent with transient synovitis?
Pain free on passive movement
What four things together have a 93-99% specificity for septic arthritis?
Prior to joint aspiration
Fever
Inability to weight bear
WCC > 12
ESR > 40 mm
Which cervical spinal injuries are most common in children <8yo
<8 = C1-3
> 8 = C4-7
What are normal findings in a paediatric cervical spine x-ray?
Absence of lordosis
C 2/3 pseudosubluxation Up to 4mm
Anterior arch of C1 not visible until 2 years old
Notching of anterior and posterior vertebral bodies by vascular channels
Predental space:
0-8yo = <5mm
>8 = <3mm
synchondrosis at base of odontoid peg can look like fracture
Apical odontoid epiphysis appears at 7 and fuses at 12 yo (mimics fracture)
What % of clavicular fractures involve the medial (proximal portion)?
5%
What sort of injuries cause sternoclavicular dislocation?
V HIGH NRG
What complications can occur in sternoclavicular dislocation?
Superior mediastinal vessel injury
Pneumothorax
Oseophageal/tracheal compression
Need closed/open reduction under anaesthesia
What’s a common mechanism of rotator cuff tear and the most commonly injured component?
HyperABduction or hyperextension
Supraspinatus tendon + muscle
At what range of motion do rotator cuff tear patients have pain and weakness?
60-120 degrees
+
external rotation
What are patients with chronic rotator cuff impingement ar risk of?
Acute tear
What clinical test can be performed to assess for rotator cuff tear?
Drop arm test
POSITIVE
Can’t lower an abducted arm at 90 degrees without it dropping
Best initial test for rotator cuff tears?
Ultrasound
High sensitivity
What % of shoulder dislocations are posterior?
2%
What are the positions of the humerus in posterior dislocation?
Subacromial (most common)
Subglenoid
Subspinous
What are the x-ray findings of posterior shoulder dislocation?
Loss of halfmoon overlap (b/w glenoid and fossa and humeral head)
Lightbulb sign - internally rotated humeral head
Empty glenoid - rim sign
Trough line = REVERSE hill-sachs deformity (# of anteromedial humeral head)
Anterior dislocation = hill-sachs deformity which is posterlateral fracture of the “hill” of the humerus
DEPALMA method to reduce post dislocation: adduct/int rotate with caudal traction then push upper arm laterally
What x-ray view can confirm a posterior dislocation of the humerus?
Transcapular Y view
What are criteria for reduction of a radial fracture?
> 10 degrees of dorsal tilt
5 degrees increase in volar tilt (11 is normal lateral view)
Radial shortening of 5mm or more (13 mm is normal)
Articular stepoff >2mm
Radial inclination change >5 degrees (23 is normal)
What is the contiuum of wrist ligamentous injuries?
Stage I = scapholunate DISSOCIATION >3mm
II = perilunate dislocation
III = perilunate dislocation + dislocation/# of triquetrum
IV = lunate dislocation
lunate dislocation = 95% have associated scaphoid fracture
What’s kienbock disease?
AVN of lunate after scapholunate dissociation
What does this show and what are the two signs?
Scapholunate dislocation
LUNATE is dislocated here
Green arrows = “piece of pie” sign
Yellow = “Spilled teacup”
Note that the lunate is on it’s side here
If the lunate is in line with the radius and enlocated then the dislocation is going to be perilunate (capitate) which is a totally different process
What are the “terry-thomas” and “signet ring” signs?
Both related to scapho-lunate DISSOCIATION (NOT DISLOCATION)
Terry-thomas = >3mm widening of scapholunate gap (usually need clenched fist view to see this)
Signet ring sign = scaphoid ring due to subluxation
TT
What is the sensitivity of MRI for scapholunate DISSOCIATION?
Only 60%!
BUT!!
If you get a cine-MRI then the sensitivity is 85% and spec is 90% which is similar to arthroscopy
Cine-MRI gets a video of the joint moving!
What is scapholunate dislocation and dissociation?
Dissociation = easy to miss, low sensitivity on normal MRI, need cine MRI (cine = cinema aka moving!) results in kiebocks disease. XR = signet ring and terry thomas sign
Dislocation = piece of pie, spilt teacup, very difficult to reduce in ED
What does this show?
Perilunate dislocation
Lunate and radius remain enlocated
Capitate dorsally dislocated in relation to lunate and radius
Usually minimal wrist deformity on examination!
What is the rate of associated scaphoid fracture in PERILUNATE dislocation?
60%
At what level can you reimplant a finger amputation?
Old textbooks (Dunn’s and DeAlwis) will say you can’t do it proximal to the FDS insertion
THIS IS OLD THINKING
Theres two really good plastics RCTs 2011 and 2020 which have two findings:
1. Advances in microvascular surgery mean complete finger avulsion reimplantation is possible with reasonable functional outcomes
2. Multi-digit reimplantation has equal outcomes to single digit
If it comes up in the exam you might have to put proximal to FDS can’t reimplant - but don’t be a dummy and do this in real life.
What level should a limb be at in compartment syndrome?
AT the level of the heart
DO NOT elevate it (reduces perfusion pressue and can worsen ischaemia!)
What is the most common limb fracture to cause compartment syndrome?
Tibia!
40% cases
Forearm second most common
What are some causes of compartment syndrome?
Fracture
Ischaemic reperfusion injury
Haemorrhage
Constrictive casts
Intra-arterial drug injection
Contrast extravasation
Crush injury
Burns
Envenomation
What pressure correlates best with compartment syndrome?
Delta pressure!
Difference between compartmental pressure and diastolic BP
<30mmHg v concerning)
noraml compartmental pressure <10mmHg
What is delta pressure in relation to compartment syndrome?
It is the difference between diastolic pressure and intracompartmental pressure
<30mmHg is an EMERGENCY! URGENT BP support and fasciotomy
30-50mmHg detrimental if left untreated for several hours
It is more sensitive and specific for compartment syndrome than isolated compartmental pressure
What is a normal intracompartmental pressure?
<10 mmHg
How many hours of compartment syndrome causes irreverisble nerve/muscle damage and what timeframe of Rx can functional impairment be avoided?
8HRS = irreversible
Within 6 hours = functional
What are the four compartments of the lower leg?
Anterior: tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles, the deep peroneal nerve, and the anterior tibial artery
Deep posterior: tibialis posterior, flexor hallucis longus, and flexor digitorum longus muscles, the tibial nerve, & posterior tibial and peroneal arteries
Lateral compartment: peroneus longus and peroneus brevis muscles & superficial peroneal nerve
Superficial posterior gastrocnemius and soleus muscles
Which compartments of the leg are most affected by compartment syndrome?
Anterior
&
Deep posterior
What are the two most common symptoms of compartment syndrome?
- Excessive/pain out of proportion to injury (90%)
- Parsthesiae in nerve distribution (60%)
When does limb ischaemia occur in compartment syndrome?
LATE!
Therefore can have a warm and well perfused limb with intact pulses and compartment syndrome be present
What two methods of movement will be painful in compartment syndrome?
Active
&
Passive
stretching
What are the mortality rates of a NOF in the elderly at 1 month, 6 months and 1 year?
1 month = 10%
6 months = 25%
12 months = 35%
What is a “3 in 1” nerve block and why is it recommended in NOF?
3 in 1 refers to the nerves supplying the hip = femoral, obturator and lat cutaneous n of the thigh
These are all covered by the fascioiliacal block with variability of obturator cover
How many miligrams of ropivacaine are there in 20mls of 0.75% and what is the safe max dosage in mg/kg?
% x 10 = mg/ml
7.5mg/ml
Therefore in 20 mls = 150mg
MAX SAFE DOSE = 3mg/kg
Therefore reduce dose under 50kg!!
What factors reduce or increase mortality in NOF # in the elderly?
M > F mortality
Surgery within 48 hours reduces mortality
Which is the most sensitive imaging modality for occult fractures (in elderly)?
MRI
Better than CT
What percentage of elderly patients with symptoms in the hip who have a NORMAL x-ray have an occult fracture on MRI?
30%!
When will a bone scan become positive fracture (post injury)??
Takes 3-5 days for new bone formation at fracture site so won’t show up on a bone scan straight away!
What % of hip dislocation are anterior v posterior?
Posterior = 90%
Anterior = 10%
In a native hip dislocation how long until femoral head AVN occurs?
6 hours!
Get it back in!
How many times should a native hip relocation be attempted in ED?
MAX 2
Multiple attempts = OT
Why can hip relocation be difficult and what fractures are associated with them?
Entrapment of a tendon or the capsule in the joint
Acetabular and femoral head fractures
Which collateral ligament of the knee is most commonly injured?
Medial
What nerve injury is associated with lateral collateral ligament injuries?
Peroneal nerve injury
What causes 75% of traumatic knee haemarthoses?
ACL injury
What knee examination finding would indicate complete collateral ligament tear?
> 1cm laxity varus/valgus with no end-point = complete
End-point suggests partial
How is the Lachman test performed?
Knee 20-30 degrees with patient supine
Anterior pull on lower limb
What suspected injury is the Lachman test used in?
ACL
What is the sens/spec of Lachman test?
85% sens
60% specific
Best examination for ACL
Wassis is ven?
Segond fracture
Suggestive of ACL injury
What’s this?
Reverse Segond
PCL/MCL injury!
What meniscal injury is ACL tear associated with?
Medial meniscus
Whats the best examination finding for meniscal injury?
There isn’t one!
Composite examination is required and yields the most information
What’s the sensitivity/spec of the McMurray test for meniscal injury?
50/50
i.e. shite!
Which is the most common ankle sprain?
ATFL
(2/3rds)
aka LATERAL
What can mimic a lateral ankle sprain?
Peroneal tendon subluxation/dislocation
Posterolateral malleolus bruising
What fracture is associated with MCL sprains?
Maisonneuve fracture
Fracture of proximal or midshaft tibia!
What test can be used to identify associated syndesmotic injury with ankle sprain?
Cross-legged test
Regarding ankle x-rays what does avulsion fracture help identify?
The location of ligament injury
What’s this?
Teardrop joint effusion
May suggest intra-articular fracture of the talar dome
What should the medial ankle joint space be in mm?
Max 4mm
What should the distance be between medial fib cortex and posterior edge of tibial groove?
<6mm
Might indicate tibiofibular diastsis (syndesmotic injury)
How much should the tib and fib overlap on ankle XR?
10mm
Why is weak plantar flexion still possible in Achilles tendon rupture?
Tibialis posteiror and peroneal muscles allow weak flexion
What examination findings can be helpful in diagnosing achilles tendon rupture?
Thompson test = loss of plantaflexion on calf squeeze
Hyperdorsiflexion sign = easy passive dorsiflexion
Palpable defect
How do talar dome fractures present?
Like an ankle sprain!
Also caused by inversion injury
May mimic and be missed
Which laterality of the talar dome is most commonly fracture?
Neither!
Tis 50:50
😉
What are the consequences of missed talar dome fractures?
Chronic ankle pain
Osteoarthritis
Osteochrondritis dissecans = bony fragment in joint causing pain
Rx of talar dome fractures?
Casting NWB
OR
Surgical excision of fracture fragment
What is a pilon fracture?
Comminuted fracture of the distal tibial metaphysis
Massive axial force
What other fractures are associated with pilon fractures?
Calcaneus
Tibial plateau
NOF
Acetabulum
Vertebral
Huge force e.g. fall from height >3m
Which Weber fracture is most likely to be associated with tibiofibular syndesmosis disruption?
Weber C
(suprasyndesmotic)
What does the lisfranc ligament connect?
Medial cuneiform
&
Base of 2nd MT
What XR features suggests lisfranc injury?
Diastasis 1mm or more between 1st and 2nd MTs
What injuries are associated with Lisfranc?
MT #
Tarsal #
LOSS of foot arch height
Dorsalis Pedis artery injury
Compartment syndrome of foot!
What anatomically occurs in facet joint dislocation?
Inferior facet of a vertebrae dislocates over the superior facet of the vertebrae below it
How do you differentiate uni from bilateral facet joint dislocation on lateral c-spine XR?
Unilat <50% verteberal body
Bilat = >50% VB
UNilateral is STABLE (often nerve root injury)
bilateral = complete cord syndrome!!
How is bilateral perched facets different from bilateral facet dislocation?
Perched facets saves the patient from cord injury but is UNSTABLE and needs emergent management
What ligaments provide stability to the cervical spine?
Anterior + posterior longitudinal ligaments
Transverse ligament
What are the 3 types of spinal ligamentous injury?
Hyperflexion sprain = fanning of spinous processes/facet joint malalignment
Hyperextension = widening of anterior intervertebral disc space
Transverse ligament tear = predental space >3mm
How long does lumbosacral back pain take to improve?
60-70% within 6 weeks (even with radicular symptoms!)
90% by 12 weeks
Activity improves pain at 3-4 wks as well as functional status
Is cauda equina common in spinal canal stenosis?
No
When does pain occur in spinal canal stenosis?
While walking but the symptoms continue when they stop walking (unlike vascular claudication)
Vibe?
Vibe!
Who does spinal canal stenosis occur in and why?
Elderly
Disc degen/facet OA/ligamentum flavum hypertrophy
Lateral recess stenosis = sciatica symptoms
Spondylolisthesis = isolated low back pain
What are the four Kanavel signs?
Finger in flexion
Fusiform swelling
Flexor tendon sheath tenderness
Pain on passive extension
What are the complications of flexor tendon sheath infection?
Flexor tendon necrosis
Digital contracture
Most common site of OM in adults vs paeds?
Adults = spine
Kids = long bones metaphysis
Both staph aureus most commonly
What % of scaphoid fractures aren’t visible on XR?
30%
What’s the most sensitive test for scaphoid # within 24 hours?
MRI
Almost 100% sens and spec within 24 hours!
What’s the most sensitive test for scaphoid fracture at 3 days?
BONE SCAN
100% sensitive at 72 hrs
Less specific
This is an MCQ
Whats the most high risk part of the scaphoid to cause AVN when fractured?
Proximal
25% AVN rate
Most common part of scaphoid to be fractured?
Scaphoid waist
65%
What is the classification system for talar neck fractures?
Hawkins I - IV
Always need CT
I is minimally displaced but still AVN risk 10% and goes up to 100% with type IV
Most get ORIF
What is the important measurement in calcaneal fractures and what is abnormal?
Boehlers angle
<20 degrees = abnormal
What’s the most important 5th MT fracture?
JONES #!!
2cm distal from base
Intra-articular # through metaphysis with high rate of non-union
When does SUFE occur and what can be measured on XR?
> 10
High BMI boys
Line of Klein!
LOK should intersect the lateral aspect of the epiphysis
If it does not run through the epiphysis in slippage this is abnormal
What is the classification system for sacral fractures?
Denis classification (pronounced Den-ee)
Zone 1-3
1 = lateral to foramina
Low neurological injury (5%) -> L4/5 nerve root
2 = 30% neuro injury L5-S2
3 = involves spinal canal. 60% have bladder/bowel/sexual function impairment
What is the commonest site of mandibular fracture?
Body
Mandibular fractures always considered open due to mucosal disruption = abx + tetanus prophylaxis
What is a NOE complex #?
Naso-orbital-ethmoid #
Avulsion medial canthal ligament
Enopthlamus
Laterally displaced palpebral fissure
>4cm intercanthal distance
Classify La Forte Fractures?
May have to go straight for FONA if lots of airway swelling
What are McGrigor Campbell lines?
What can become entrapped in zygoma fractures?
Masseter
What 3 bones are fractured in a tripod #?
Maxilla (+infraorbital rim)
Frontal
Temporal
What complications can occur from a tripod #?
Facial flattening/asymmetry
Infraorbital n anaesthesiae
Diplopia
Which pelvic bone is the first ossification centre to appear and also last to close?
Ilium
Appears @ 8 weeks in utero
