Upper Limb Fractures Flashcards
Define Fracture
Fracture is the (local) separation of an object or material into two, or more, pieces under the action of stress
List the 4 ways we classify fractures + what each means
- Open/Closed: communication with skin
- Complete/Incomplete: fragments 2 or more
- Simple/Comminuted: all cortex disrupted
- Direction
Apposition and alignment are defined in relation to ______ fragments
distal
List 5 terms used to describe apposition and alignment of fragments in a fracture
- displacement (medial lateral, posterior, anterior)
- angulation (medial, lateral, posterior, anterior)
- rotation (internal, external)
- overriding: overlap of fragments
- distracted: separated fragments
What type of fracture is shown
Complete fracture
What type of fracture is shown + define
Green Stick Fracture
Break of one cortical margin. Only with intact periosteum due to tension on soft growing bone
What type of fracture is shown + define
Torus Fracture
Buckling of cortex due to compression
Are smokers at an increased risk of fractures? Explain your answer
Smokers generally have lower bone density than non- smokers, so have a much higher risk of fractures.
Smoking also delays bone healing
Define a pathologic fracture + give 4 causes
Fracture at site of pre-existing osseous abnormality
Causes: tumor, osteoporosis, infection, metabolic disorder
(Image shows lucency at fracture site)
Compare a Stress vs Insufficiency fracture
(Fatigue) Stress Fracture are produced as a result of repetitive prolonged muscular action on bone that has not accommodated itself to such actions, activity related pain abating with rest
Insufficiency fractures occur when normal physiologic stress is applied to bone with abnormal elastic resistance/deficient mineralization
List 4 X-rays findings which may be seen with a stress fracture
- subtle blurring of trabecula margins
- sclerotic band (due to trabecular compression usually perpendicular cortex)
- gray cortex sign (subtle ill definition of cortex)
- Intra-cortical radiolucent striations (early)
What is seen on the X-ray below and therefore what type of fracture is this?
blurring of trabecula margins ➞ stress fracture
List 2 investigations to do if you suspect a stress fracture? (in additon to an X-ray)
- Bone Scan (gold standard)
- MRI
What may be seen on a bone scan in a patient with a stress fracture?
Stress fracture will appear as an area of increased uptake of tracer. Abnormal uptake is seen within 6-72 hours of injury ➞ prior to radiographic abnormality
If less intense (prefracture), ususally termed as stress reaction (focus of subtly increased uptake)
Abnormal uptake persists for months
Give 4 common sites for stress fractures to occur
Give 4 causes of an Insufficiency fracture
- osteoporosis
- paget/FD
- osteopetrosis
- osteomalacia/Rickets
- radiation
Give 3 X-ray findings indicative of an insufficency fracture
- Cortical lucency
- Periosteal reaction
- Sclerosis
List an MRI finding indicative of a Insufficiency Fracture
Marrow edema (low T1 High T2)
What type of fracture is this and why
Pelvic Insufficiency Fracture
- Fracture line
- Callus formation
- Honda sign: asymmetric incomplete H-shaped pattern of sacral uptake
Pathological Fractures are based on what 4 characteristics?
- tumor location
- associated pain
- type of lesion (either lucent, mixed, or blastic)
- lesion size
How are tumours scored?
1-3
If tumour is scored an 8+ what is advised surgically?
Fixation
What is Salter Harris?
Classification for Epiphyseal plate Injury
State the following regarding Epiphyseal plate Injurys
- peak age
- most common location
- upper vs lower limb prognosis
- shear force/compression
Peak age: 12 y
Radius most common (30%) others incl phalanges, distal tibia, humerus, ulna
Lower limb = worse prognosis
80% shearing force; 20% compression
List the 5 Salter Harris classifcations and explain each
State the following about a Type I fracture on the SH classification
- What/why
- Location
- Prognosis
State the following about a Type II fracture on the SH classification
- What/why
- Location
- Prognosis
State the following about a Type III fracture on the SH classification
- What/why
- Location
- Prognosis
State the following about a Type IV fracture on the SH classification
- What/why
- Location
- Prognosis
State the following about a Type V fracture on the SH classification
- What/why
- Location
- Prognosis
State the following about the SH classification:
- Type _____ is most common
- Types _____ & _____ are more prone to chronic disability
- Type _____ associated with growth disturbances and has a poor functional prognosis
- II
- III & IV
- V
List the 3 features of a Triplane Fracture
- vertical fracture of epiphysis
- horizontal cleavage plane within physis
- oblique fracture of adjacent metaphysis
List 2 complications of a Triplane Fracture
- progressive deformity from segmental arrest of germinal zone growth with formation of a bone bridge across physis = “bone bar”
- limb length discrepancy from total cessation of growth
What is meant by “ulnar variance” in a hand fracture?
Ulnar variance refers to the relative lengths of the distal articular surfaces of the radius and ulna.
What are the 3 types of ulnar variance and explain each
Neutral: both articular surfaces the same length
Positive: ulnar surface longer
Negative: ulnar surface shorter
What disease is associated with a positive vs negative ulnar variance
Positive ulnar variance is associated with Ulnar Impaction Syndrome.
Negative ulnar variance is associated with Kienbock disease
What is shown on the X-ray below?
What may a loss of these arcs indicate
Carpal Arcs: X-ray shows 3 arcs carpus intact
Loss of the arcs may indicate carpal dislocation
What are the 2 types of Intra-articular thumb metacarpal fractures?
- Bennett
- Rolando
What is a Bennett Fracture and how does it occur?
Intra-articular fracture-dislocation of base of 1st metacarpal due to forced abduction of thumb
Forced abduction causes fracture ➞ small fragment of 1st metacarpal, attached to anterior oblique ligament, continues to articulate with trapezium
Pull of AbPL causes dislocation ➞ displaced proximally
What is a Rolando Fracture and how does it occur?
Intra-articular Y/T shaped comminuted fracture through the thumb metacarpal
Mechanism: forced abduction of thumb
Compare a Bennet vs Rolando Fracture
Both are intra-articular fractures at the base of the first metacarpal
BUT Bennet is not dislocated vs Rolando which is. Rolando is also comminuted (worse prognosis)
What is a Boxer’s Fracture and where does it most commonlv occur?
Fracture of the MCP neck with volar angulation and often external rotation of the distal fragment
(Most commonlv 5th MCP)
What is the most common fracture of carpus and how does it usually occur?
Scaphoid Fracture usually due to a fall on outstretched hand in young adults
Give the 3 ways we classify a Scaphoid fracture based on location + state how common each is
Waist 70%
Proximal pole 20%
Distal pole, 10%
A scaphoid fracture at which location are we most concered about and why?
The proximal pole
This is because blood supply to the proximal pole enters at the waist therefore the proximal pole is at high risk for nonunion and osteonecrosis
A Scaphoid Fracture may be difficult to detect on plain film, what may we be able to see?
Loss of navicular fat stripe on PA view
If a fracture is clinically suspected but not Radiographically detected what 3 things can we use
- Bonescan
- MRI
- Cast and repeat plain films in two week.
Give the prognosis of a scaphoid fracture at each location
Waist fracture: 90% heal evenfually, 10% nonunion or proximal avascular necrosis (AVN)
Proximal fracture: high incidence of nonunion or AVN
Distal fracture: usually heals without complications
Give 2 types of Carpal Fractures
What fracture is shown below + explain
Baseball (mallet) finger
Dorsal avulsion of the extensor mechanism at the DIPJ ➞ results in inability to flex the DIPJ
(Can be with or without avulsion fragment)
What fracture is shown below
Volar plate fracture: avulsion at base of middle phalanx resulting in hyperextension
What is a Barton’s Fracture?
How would we treat?
Intra-articular fracture of the volar or dorsal margin of the distal radius. The carpus usually follows the distal fragment.
Unstable fracture requiring open reduction and internal fixation and/or external fixation.
What is a Chauffeur Fracture
Triangular fracture of radial styloid process.
What fracture is shown below + give its mechanism of injury
Colle’s Fracture
Mechanism of injury: fall on the out streched hand with the forearm pronated in dorsiflexion (most common injury to distal forearm)
Give 4 Radiographic features of a Colle’s fracture
- Extra-articular fracture
- Distal radius is dorsally displaced/angulated
- Ulnar styloid fracture also occur in 50%
- Foreshortening of Radius
Compare a Colle’s vs Barton’s Fracture
Barton’s = Intra-articular fracture
Colle’s = Extra-articular fracture
Give 3 complications of a Colle’s fracture
- Median nerve injury
- Ulna nerve injury
- Osteoarthritis
What is a Smith’s fracture
Same as Colles’ fracture except there is volar displacement and angulation of the distal fragment
Give the 3 types of Smiths fractures
Type 1: horizontal fracture line
Type2: oblique fracture line
Type 3: intraarticular oblique fracture
Give the 3 features of a Essex-Lopresti Fracture
- comminuted displaced radial head fracture
- dislocation of distal radio-ulnar joint
- rupture of the interosseous membrane (radiopedia)
Give the 2 features of a Galeazzi Fracture and where does it most commonly occur?
- radial shaft fracture (most commonly) at junction of distal to middle third with dorsal angulation
- dislocation of distal radio-ulnar joint
Ulnar plus variance (radial shortening) in a Galeazzi Fracture implies what?
complete disruption of interosseous membrane (instability of radio-ulnar joint)
What is a Monteggia-type Fracture
Fracture of ulnar shaft + dislocation of radial head (4 types)
Describe the 2 features of a Type I (classic) Monteggia fracture
State the mechanism of injury
- Anterior dislocation of radial head
- Anteriorly angulated proximal ulnar fracture
Mechanism: direct blow to the forearm
Describe 2 features of a Type II (reverse) Monteggia fracture
- Radial head displaced posteriorly
- Dorsally angulated proximal ulnar fracture
Describe 2 features of a Type III Monteggia fracture
- Anterolateral dislocation of radial head
- Ulnar metaphyseal facture
Describe 2 features of a Type IV Monteggia fracture
- Anterior displacement of radial head
- Fracture of proximal third of radius + ulna at the same level
What is the Fat Pad Sign and when is it seen?
Fat Pad Sign is seen when there is displacement of either/ both of the Anterior fat pad or Posterior fat pad of the elbow
Clinically these indicate there is elbow joint effusion due to supracondylar/lateral condylar/proximal ulnar or radial fractures
What 4 important questions must we ask ourself in a suspected elbow fracture?
- Joint effusion?
- Normal allignment?
- Normal ossification centres?
- Subtle fracture?
What 2 lines are we looking at when assessing elbow ‘allignment’
What is considered normal for each in children?
Radio-Capitellar Line ➞ line drawn down radial neck should intersect the capitellum
Anterior Humeral Line ➞ line drawn down anterior surface of humerus should intersect middle third of the capitellum
Describe 3 features of a Supracondylar Fracture and how it usually occurs
- Transverse fracture line
- Distal fragment posteriorly displaced/ tilted
- Anterior humeral line does not intersect middle third of capitellum ➞ distal fragment posteriorly displaced/tilted
Mechanism: Hyperextension with vertical stress
What classification is used for Supracondylar fractures + give the 3 types
Gartland Classification
type I: minimally displaced
type II: displaced distil fragment with intact posterior cortex
type III: complete displacement (posteromedial 75%, posterolateral 25%)
What are the 2 sites where an avulsion fracture of the elbow occurs?
Lateral and Medial condyle
Elbow avulsion fractures and supracondylar fractures almost always affect what age group?
Children!!
How do Radial Head Fractures usually occur?
fall on outstretched hand
On an X-ray of a radial head fracture the fracture line may be difficult to see. What other radioghraphic feature may be present?
Positive fat pad sign
Give the 3 treatment options for a Radial Head Fracture and when each would be used
No displacement: splint, cast
More than 3 mm displacement on lateral view: open reduction and internal fixation
Comminuted: exicision of radial head
Who do Humeral Head Fractures usually occur in?
common in osteoporotic elderly patients secondary to fall on outstretched hand
What is meant by the ‘4-segment Neer classification’ for Humeral Head Fractures
Classified based on number and type of displaced segments.
4 segments: anatomical neck, surgical neck, greater tuberosity, lesser tuberosity.
Give 2 Radiographic features of a Humeral Head Fracture
- Fracture lines according to Neer classification
- Pseudosubluxation: inferior displacement of humeral head due to hemarthrosis
Clavicle Fractures are common in ______. The distal fragment is displaced ______ and ______.
children, inferior, medial
What are the 3 sites of a clavicle fracture + how common each is
Lateral third: 15%
Middle third: 80%
Medial third: 5%
What type of fracture is shown below?
Fracture to the lateral 1/3 of the clavicle
What can be said about the acromium and clavicle radiologically in a normal person?
In the normal patient, the inferior surfaces of the acromion and clavicle are aligned
What are the 3 grades of an Acromio-Clavicular dislocation
Grade I are radiographically normal
Grade II show widening of the joint with upward displacement of the clavicle
Grade III have a widened coraco- clavicular space 13 mm
What fracture is shown on the X-ray below?
Acromio-clavicular dislocation
How common are Scapula Fractures and how do they usually occur?
Uncommon, often caused by motor vehicle accident, fall from height (direct impact injuries).
What is the best radiographic view to investigate a scapula fracture?
Transscapular view (Y-view), CT often helpful
What is a Scapho-lunate Dissociation?
Give 2 radiological signs associated with this
Rupture of scapho-lunate ligament
- 3-mm gap between lunate and scaphoid - Terry-Thomas sign
- Ring sign on PA view secondary to rotary subluxation of scaphoid
How are elbow dislocations defined and which is the most common
What fractures are often associated with this injury?
Defined by the relation of radius/ulna to distal humerus ➞
Posterior dislocations of both the radius and ulna are the most common type (90%).
Often associated with coronoid process or radial head fractures
Compare a shoulder dislocation vs subluxation
Dislocation: separation of articular surface of glenoid fossa and humeral head that will not reduce spontaneously.
Subluxation: transient incomplete separation that reduces spontaneously
Dislocation is divided into two large categories, what are these?
- TUBS (Traumatic, Unidirectional, Bankart, requires Surgery)
- AMBRI (Atraumatic, Multidirectional, Bilateral, Recurrent Instability)
What does the X-ray below show?
Shoulder dislocation
What are the 2 directions of shoulder dislocation?
How does each occur and which is most common?
Anterior dislocation (95%) and Posterior dislocation (5%)
Mechanism of injury
- Anterior ➞ usually a blow to an abducted, externally rotated and extended arm
- Posterior ➞ usually due to direct or indirect force
On an X-ray of an anterior shoulder dislocation, the humeral head lies ______ and ______to glenoid
inferior, medial
In anterior shoulder dislocation, 2 lesions can occur as the humeral head strikes the glenoid.
What is the name of these lesions and on which view are they most visible?
- Hill-Sachs lesion (posterior-superior and lateral) of humeral head, (best seen on Ap view with internal rotation)
- Bankart lesion (antero-inferior) of glenoid (may require CT)
On an X-ray of a posterior shoulder dislocation, the humeral head lies ______ to glenoid. Posterior displacement is best seen on ______ view.
superior, axillary
Give 3 Radiographic signs seen in a posterior shoulder dislocation + explain each
Trough sign: compression fracture of the anterior humeral surface
Light bulb sign: circular appearance of humeral head, due to arm fixed in internal rotation
Rim sign (66%): distance between medial border of humeral head + anterior glenoid rim >6 mm (widened)
