Week 5 Flashcards
How many views do we need for a cervical spine and a scaphoid x ray
3
What are the views we need for a cervical spine xray
lateral
antero posterior
odontoid/open mouth view
What are the views we need for a scaphoid xray
lateral
anteroposterior
two obliques
Symptoms of scaphoid fracture
Tenderness at anatomic snuff box
Pain on compressing the thumb metatarsal
Where is the anatomic snuff box
Between the Abductor pollicis brevis + extensor pollicis brevis and extensor pollicis longus tendons
(when fingers abducted, it is below the thumb)
What is the cortical layer of the bone
dense outer surface of bone
What fracture appearances are there
Cortical extension (extends to the cortical layer of bone)
Spiral
Transverse
Comminuted
Angulation
Displacement
Impaction
Avulsion
What is an angulation fracture
The fracture displaces the bone; the normal axis of the bone is altered so that the distal portion of the bone is pointed into another direction
What is an impaction fraction
when two pieces of a fractured bone are driven into each other
What is an avulsion fracture
When a small piece of bone attached to a ligament or tendon gets pulled away from the main part
What causes avulsion fracture
due to bone is moving one way, and a tendon or ligament is suddenly pulled the opposite way
What can mimic avulsion fractures
Old injuries and normal anatomy
What is the difference between an actual avulsion fracture and an avulsion fracture mimic
An avulsion fracture mimic will be completely corticated whereas an avulsion fracture is not
How to tell if a bone fragment is corticated
Dense outer layer - grey colour on all sides
What bones can mimic avulsion fractures
sesamoid bones
accessory ossification centers
What is the posterior fat pad sign
When an elbow effusion is present, the posterior fat pad at distal humerus will be displaced and become visible (posterior fat pads should not be visible)
What does the fat pad at the elbow look like on xray
Black-ish appearance, black appearance will be next to distal humerus
What do children’s bones do instead of snap and splinter like adult ones when they sustain an injury
Bend or bow
Why don’t children’s bones snap when they sustain an injury
Because their bones are soft
What fractures do children usually get
Buckle fracture
Plastic bowing
Greenstick fracture
What is a buckle fracture and what does it look like
Incomplete fracture that happens when the bone is pressed to the point it bulges out
looks like a bump on the bone
What is a greenstick fracture
Incomplete fracture that happens when the bone is bent to the point it breaks but it doesn’t break all the way through (cracks without breaking completely)
Is avulsion fracture more common in adults or children
Children
Which part of the developing bone is the weakest
growth plate
What can result from a growth plate fracture
Growth deformity such as shorter limb / crooked limb
Where is the growth plate normally located at
It is a lucency between the epiphysis and metaphysis
Fractures in which bone is often associated with injuries in other areas too
femoral fractures
Why should you suspect injuries in other areas too if there is a femoral fracture
Because femoral fractures are high energy injuries
2 Steps management for femoral shaft fractures
- Analgesia + Thomas splint
- Closed reduction + IM nail
How can fat embolism occur in displaced femoral shaft fracture
Fat enters the damaged venous system
What can happen as a result of fat embolism caused by displaced femoral fracture
Hypoxia
Confusion
Acute respiratory distress syndrome
What should you expect if you see a bony ring (such as spinal canal) is injured
there should be 2 or more injuries of the bony ring because it is difficult to disrupt the ring in only one place
Why can wood and plastic splinters be invisible on xrays
Not dense enough; to be shown on the xray, the object needs to be in different density
Which type of shoulder dislocation may not be seen properly on xray AP view
When the humerus dislocates posteriorly
What should you do if you can’t see the posterior shoulder dislocation on AP view
Do oblique view
Which artery can be damaged by supracondylar fracture
brachial artery
What should you do if you still can’t spot scaphoid fracture after 3 different views
Repeat xray 10 days after
MRI
What can scaphoid fracture cause
Damage to scaphoid blood supply, causing necrosis and leads to early osteoarthritis
Necrosis of which pole can be caused by scaphoid fracture
Proximal pole
Management of undisplaced scaphoid fracture
Cast
Where does the blood supply for scaphoid come from
Distally from a branch of radial artery
Which devices can show soft tissue injuries
Ultrasound
MRI
Which ring-like bones usually have more than 1 site of injury when damaged
Pelvic ring
Spinal ring
Tibia and fibula
Radius and ulna
Pelvic ring fractures usually occur in
Elderly people with osteoporosis after a minor fall
Which structures are usually affected by pelvic fractures
pubic rami
sacrum
What are the soft tissues of the knee that you must examine as well and why
Patellar tendon
Quadricep tendon
Suprapatellar fat space
avulsion fracture can indicate soft tissue injury
What other clinical finding is usually accompanied with soft tissue injury of the knee
effusion filling suprapatellar space
Which artery can be disrupted by knee dislocation
Popliteal artery
Which structure of the tibial plateau is usually affected
lateral condyle
What injury mechanism causes tibial plateau fracture
valgus force (force coming into contact with outer side of knee) with foot planted
Extensor mechanism (quadriceps and patellar tendon) injuries of the knee can be seen by which device
Ultrasound
Which knee injuries can be shown in MRI
Meniscal tears
ACL/PCL/LCL/MCL
hyaline cartilage damage
What clinical presentation can be shown by displaced, torn meniscus
Locked knee
Which device can show complex ankle fractures
CT
What is a talar dome lesion
Injury at the upper part of talus - could be cartilage injury / the underlying talus bone
What do calcaneal compression fractures look like
Loss of central peak and increased bone density
What injury mechanism causes calcaneal compression fracture
Axial compression e.g. falling from height onto the heel
What is a common fracture mimic in the foot
Longitudinal accessory ossification center of the 5th metatarsal
What is a common fracture mimic in the leg
Fabella ; sesamoid bone posterior to distal femur
What conditions can predispose to tendon rupture
Diabetes
Rheumatoid Arthritis
Steroid use
Which nerve is at risk of damage due to anterior dislocation of glenohumeral joint and why
Axillary or Radial nerve because the posterior cord is behind the glenohumeral joint
Which cord of the brachial plexus is behind the glenohumeral joint
Posterior cord which branches to axillary and radial nerve
Which neck of the humerus is most prone to fractures
Surgical neck
Where is the anatomical neck of the humerus located at
The groove between the humerus head and the greater tuberosity
Which nerve is at risk of damage due to fracture of the surgical neck of humerus and why
Axillary nerve because it is a circumflex nerve around the surgical neck of the humerus
Which muscles are supplied by the axillary nerve
Deltoid
Teres minor
Function of the teres minor muscle
It is a rotator cuff muscle
It helps with external rotation
Function of the deltoid muscle
Abduction of the arm
What happens when the axillary nerve is damaged
Difficulty / Inability to lift your arm
Muscle weakness
Muscle wasting
Paraesthesia
Numbness
Pain
What is the classical sign of radial nerve damage
Wrist drop
Loss of sensation at dorsal web space
Fracture in which location can cause damage to the radial nerve
Fracture of humerus around its shaft
What artery is at risk of damage if there is a humeral shaft fracture and why
Deep brachial artery because it lies near the radial groove
Management of undisplaced proximal humeral fracture
Non-operatively with collar and cuff
How may the triceps brachii be involved in fracture of the humerus
Proximal fracture at the shaft of the humerus can damage the branch of radial nerve that innervates the triceps brachii, causing loss of function of the triceps
Wasting of which muscles can be caused by ulnar nerve injury
Adductor Pollicis
Hypothenar eminence
What are mucous cysts of the hand
a type of ganglion (outpouchings of synovial fluid) that occurs at DIP
Where do mucous cysts usually occur on hands
DIP
Which condition is associated with mucous cysts
Osteoarthritis
What possible symptoms can mucous cysts cause
Nails can grow irregularly due to the cyst growing near nail beds
May be painful
May rupture and release discharge
Management of mucous cysts
Nothing
Excision only indicated if it causes pain / at risk of rupturing
What are ganglions
Outpouchings of synovial fluid
Where do ganglions occur
DIP (mucous cyst)
Wrist
knee
foot and ankle
What is the ganglion present at the knee called
Baker’s cyst
Management of ganglions
Nothing
needle aspiration or surgery if causing localised discomfort
What is the problem of needle aspiration for ganglions
High recurrence rate
What should you beware of when performing needle aspiration of volar ganglion cyst
Radial artery is nearby
What is a pulley
ligamentous strap that keeps tendons close to the bone to create an optimal line of pulling
Tendons glide smoothly through the pulleys during flexion and extension