MSK Injury & Orthopaedics Flashcards
How can you examine for nerve root pain in the lower limbs?
Straight leg test for sciatica (L4, L5, S1)
Femoral stretch test for femoral nerve irritation (L2-L4)
What are the two joints in the ankle and what movements do they facilitate?
Subtalar joint
- Calcaneus + talus
- Facilitates eversion/inversion
True ankle joint
- Tibia, fibula, talus
- Facilitates dorsi/plantarflexion
What usually causes an ankle ligament strain?
Inversion injury (85%) - a sprain of the lateral ligament complex (injury to the anterior talofibular ligament is most common)
e.g. when a basketball player jumps and lands improperly
What can help you decide if an X-Ray is needed to rule out a fracture in ankle injury?
Ottawa ankle rule:
- Inability to weight bear immediately after injury and in ED
- Pain in malleolar zone plus tenderness over posterior edge of lateral or medial malleolus
How can you manage a simple ankle sprain?
POLICE
Protection from further injury Optimal Loading Ice Compression Elevation
Full recovery can take 4 weeks
Advise to come back if not full weight-bearing by 4 days
Who are distal radial fractures most common in?
Osteoporotic post-menopausal women
What are the most common distal radial fractures? What most commonly causes them?
Colles’ - falling on outstretched hand
Smiths’ - falling on flexed wrist
How does Colles’ fracture present?
Dinner fork deformity
What would be seen on an X-Ray of a Colles’ fracture?
Extra-articular fracture of the distal radius with dorsal displacement of the distal radius
If there is a grossly displaced fracture, how do you manage it?
- MUA (manipulation under anaesthetic) - Bier’s block with IV regional LA
- Apply POP backslab cast and sling
- XRay 1 week later to check position
When is MUA (manipulation under anaesthetic) urgent in a distal radius fracture?
Compound fracture (open) Nerve compression
How does a fractured NOF present?
- Pain in hip/groin/thigh radiating to knee
- Inability to weight-bear
- Affected leg is shorter
- Leg is externally rotated
- Adduction of affected leg
What should you check for in an elderly patient with a hip fracture?
Signs of dehydration
Hypothermia
They may have been lying for hours
What is a complication of an intracapsular NOF fracture?
Disruption of blood supply to femoral head causing avascular necrosis
What is the classification for intracapsular femoral neck fractures? What is it based on?
Garden classification - based on AP X-Ray
I - Incomplete undisplaced fracture with the inferior cortex intact
II - Complete undisplaced fracture through the neck
III - Complete neck fracture with partial displacement
IV - Fully displaced fracture
What is the ED (i.e. initial) management for a hip fracture to stabilise the patient?
ABCDE approach
IV access
- Bloods - FBC, U+Es, glucose, crossmatch to prepare for surgery, CK to assess for rhabdomyolysis
- IV fluids if hypotension/dehydrated
- IV morphine (titrate up) + antiemetic
Femoral nerve block with bupivacaine
AP and lateral X-Rays of the hip and AP X-Ray of the pelvis
Refer to orthopaedic surgery
On a lateral hip X-ray, what indicates a fractured neck of femur?
Interrupted Shenton’s line (imaginary curved line drawn along inferior border of superior pubic ramus to inferomedial border of neck of femur)
What is the most common type of shoulder dislocation?
Anterior dislocation (95%) - due to forced external rotation and abduction of the shoulder
Who does anterior dislocation most commonly affect?
Young males playing contact sports
Elderly patients falling on outstretched hand
What causes a posterior shoulder dislocation?
Trauma to anterior shoulder or fall onto internally rotated arm
What is found on palpation of anterior shoulder dislocation?
Loss of shoulder contour - flattening of deltoid
Anterior bulge from head of humerus - can be palpated anteriorly and in axilla
Step-off deformity at acromion with palpable gap below acromion
How can you test for injury to the axillary nerve?
Loss of sensation over lateral shoulder (regimental badge area)
Lack of contraction of deltoid during attempted abduction
What is posterior shoulder dislocation associated with?
Epileptic seizures
Electrical shocks
Direct blow during trauma
What might occur at the same time as an anterior shoulder dislocation?
Fracture of the humeral head, neck or greater tuberosity
How does radial nerve injury present?
Weakness of wrist extension and thumb abduction
Reduced sensation on dorsum of hand
Abnormal triceps and brachioradialis reflexes
What changes are seen on an X-Ray in anterior shoulder dislocation?
Humeral head lies inferior to coracoid process on AP view
Head of humerus anterior to glenoid on axillary view
What sign is seen on X-Ray of posterior shoulder dislocation?
Lightbulb sign
What is the most common method to manipulate an anterior shoulder dislocation?
External rotation method
- Patient supine on bed
- Affected arm is adducted and flexed to 90 degrees at elbow
- Arm is then slowly externally rotated
- The shoulder should be reduced before reaching the coronal plane
Describe the blood supply to the NOF
It is retrograde - it passes from distal to proximal along the femoral neck to the femoral head through the medial circumflex femoral artery, which lies directly on the neck of the femur (intra-capsular)
Define: fracture
A soft tissue injury (i.e. nerves and blood vessels) with a broken bone underlying
What are the 4 stages of bone healing?
- Haematoma
- Fibrocartilaginous callus formation (i.e. soft bone starts forming)
- Formation of bony callus
- Remodelling and addition of hard/compact bone
What are direct and indirect bone healing?
Direct/primary bone healing = perfect healing - osteoclasts form cutting cones followed by osteoblasts
Indirect/secondary bone healing = callus formation because anatomical reduction was not achieved
Where do bones get their blood supply from?
2/3rd supply is from the bone marrow
1/3rd supply is from blood vessels outside the bone
How are intracapsular NOF fractures definitively managed depending on the patient age and their Garden scale?
Garden 1/2 (i.e. non-displaced)
- Open repair and internal fixation (ORIF) with cannulated cancellous screws
- Hemiarthroplasty if major comorbidity
Garden 3/4:
- Young patients - ORIF with cannulated cancellous screws unless there is avascular necrosis when they will require total hip arthroplasty
- Elderly/immobile - Hip hemiarthroplasty
(generally want to avoid arthroplasty in young age because they only last 10-15 years and there is less range of movement)
What are the different surgical options for managing extracapsular NOF fractures? Which options are suitable for which fractures?
DHS (dynamic hip screw) - inter-trochanteric fractures that are stable and compressible (i.e. not dispaced)
Intramedullary nail - femoral shaft fractures
What needs to be consented for pre-operatively for fracture surgeries?
Pain
Bleeding
Infection at wound site
Neurovascular damage
What is a potential life-threatening complication of fractures/fracture repair surgery?
Fat emboli
How would fat emboli present in a patient?
- Hypoxia (most common symptom) - tachypnoea, dyspnoea, cyanosis, diffuse crackles
- Neurological symptoms - confusion, lethargy, seizures, focal neurological deficits, coma
- Petechial rash (50% patients and is last symptom to present) - mainly on chest wall, in axilla, head, neck, conjunctiva, buccal mucosa
How does a dynamic hip screw work in healing the bone?
The screw can glide freely in a metal sleeve
Weight bearing causes the femoral neck to impact on the femoral metaphysis, producing dynamic fracture compression
This movement is only allowed in one plane along the sleeve, resulting in anatomical reduction
As bone responds to dynamic stresses, this is intended to promote remodelling and fracture healing
What is the major orthopaedic emergency?
Compartment syndrome
What are the 6 Ps of compartment syndrome?
6 Ps - pain, pallor, paraesthesia, pulselessness, paralysis, perishingly cold!
(but really it’s just pain pain pain pain pain pain because you can still have pulses and sensation and wouldn’t have time for check for those things)
How do you examine for compartment syndrome in the leg?
Passive stretching of the hamstring muscles (i.e. passive extension of the knee)
What makes you suspect compartment syndrome?
Pain that is out of proportion with extent of injury
What is the surgical treatment for compartment syndrome?
Fasciotomy required ASAP - incisions into tissue and fascia relieves pressure and restores perfusion
Last resort - amputation
What is the ball and socket of the shoulder joint?
Ball = head of humerus
Socket = glenoid fossa
What is a Holstein-Lewis fracture? How does it present?
Fracture of the distal 1/3rd of the humerus resulting in the entrapment of the radial nerve
It results in loss of sensation over dorsum of the hand and a wrist drop deformity
How are the majority of humeral shaft fractures treated?
Conservatively with a functional humeral brace
Describe what the ankle is comprised of
Talus bone articulating within the mortise
The mortise is comprised of the medial malleolus (distal end of the tibia) and the lateral malleolus (distal end of the fibula)
The tibia and fibula are joined at the syndesmosis (a very strong fibrous structure comprised of the anterior inferior tibiofibular ligament, posterior inferior tibiofibular ligament and the intra-osseous membrane
What is an ankle fracture?
A fracture of any malleolus with or without disruption to the syndesmosis
What is the most common classification of ankle fractures? Describe the classification
Weber classification - it classifies lateral malleolus fractures
Type A = below the syndesmosis
Type B = at the level of the syndesmosis
Type C = above the level of the syndesmosis
Which type of ankle fracture is the most likely to lead to ankle instability? What does this mean for management?
The more proximal the injury, the higher the likelihood of ankle instability
Consequently, Type C fractures almost always need surgical fixation
What is the initial management of an ankle fracture?
- Immediate fracture reduction under sedation to realign the fracture to anatomical alignment
- Place the ankle in a below knee back slab and repeat a post-reduction neurovascular examination
- Request a repeat X-Ray
- If the reduction is not adequate, repeat reduction attempts
In which ankle fractures is conservative management opted for?
- Non-displaced medial malleolus fractures
- Weber A fractures
- Weber B fractures without a talar shift
- Those unfit for surgical intervention
What is the surgical management of ankle fractures?
Open reduction and internal fixation
What is the most commonly fractured tarsal bone?
Calcaneum
What is the gold standard investigation for assessing calcaneal fractures?
CT imaging
What is the main complication of a calcaneal fracture?
Subtalar arthritis
What can be used to treat complex fractures?
Ilizarov frame - a circular external fixator where the rings are fixed to the bone via pins
What usually causes a scaphoid fracture?
Fall onto an outstretched hand
What is the most important clinical sign of a scaphoid fracture? What are other signs?
Pain of palpation of the anatomical snuffbox = most important
Pain whilst telescoping the thumb
Tenderness of scaphoid tubercle on volar aspect of the wrist
Pain on ulnar deviation of the wrist
If there is no discernible fracture seen on a scaphoid series of X-Rays but there is pain in the anatomical snuffbox, what is the next step in management?
If highly suspicious of scaphoid fracture, cast the wrist in the ‘beer glass’ position and repeat X-rays taken after 10 days for repeat imaging
Scaphoid fractures may become visible radiologically after 10 days
If repeat XR still negative do MRI as definitive investigation
What is the management of a humeral head fracture?
Collar and cuff sling - allows the weight of the arm to help the fracture re-align
In which injuries is a broad arm sling indicated?
Clavicular fracture
Acromioclavicular ligament tear
Elbow injuries
Forearm fractures to support the cast
What sign may be seen on XR of distal humerus fracture?
Sail sign - raised fat pads
the fracture is not always seen on XR or may be very subtle so sail sign is a good indication of a fracture
What analgesia is used for a distal radial fracture before doing MUA?
Haematoma block
What is a Galeazzi fracture?
Fracture of distal 1/3rd of radius and dislocation of ulna
What is Barton’s fracture?
Intra-articular fracture of the distal radius with dorsal angulation of the distal fragment
(similar to Colles but intra-articular)
What level is a pelvic binder placed at?
Level of greater trochanters
How is a cervical collar sized?
Using fingers measuring from top of patient’s trapezius to point of chin
What are the indications for cervical spine immbolisation?
- GCS < 13 at initial assessment
- Intubation
- Definitive diagnosis of c-spine injury is required urgently e.g. before surgery
- Other areas are being scanned for head injury or other multi-region trauma
OR the patient is alert and stable but there is suspicion of c-spine injury and any one of the following are present:
• Age > 65 years
• Dangerous mechanism of injury = fall from a height >1m or 5 stairs
• Focal CNS deficit
• Paraesthesia in upper or lower limbs
How many doses of tetanus are required to provide long-term protection?
5 doses
Given at: • 2 months • 3 months • 4 months • 3-5 years • 13-18 years
What are the rules about when you should give a tetanus vaccine if someone presents with a wound?
If vaccination history is incomplete/unknown/last dose more than 10 years a go
• Give tetanus vaccine, regardless of wound severity
• For tetanus prone and high-risk wounds, reinforce dose of vaccine with tetanus Ig
If patient has had full course of tetanus vaccines with last dose < 10 years a go and presents with a wound - no vaccine or Ig is required, regardless of wound severity
What is the most common organism causing osteomyelitis?
S. aureus
Salmonella spp - especially if sickle cell anaemia
What is the imaging modality of choice for investigating osteomyelitis?
MRI
How does a posterior hip dislocation present? Compare this to NOF #
Posterior hip dislocation - leg is flexed, internally rotated, adducted and shortened
NOF - leg is externally rotated, adducted and shortened
If there is no NOF # seen on XR but clinical suspicion remains high, what is done?
MRI Hip
What is the major risk with scaphoid fractures? What is damaged?
Risk of avascular necrosis - damage to the dorsal carpal arch of the radial artery (which supplies 80% of blood in a retrograde manner)
What does avascular necrosis of NOF look like on XR?
Segmental flattening of femoral head and joint space narrowing
What is Brown Sequard syndrome?
Hemisection of the spinal cord (can be left or right)
How does Brown Sequard syndrome present and what has been damaged to cause those presentations?
Ipsilateral loss of proprioception and vibration below the level of the lesion - damage to posterior column
Contralateral loss of pain, temperature, touch sensations below the level of the lesion - damage to dorsal column
Ipsilateral hemiplegia (loss of muscle function)
- Flaccid paralysis at the level of the lesion - damage to LMN at level of lesion
- Spastic paralysis below the level of the lesion - damage to UMN
- Ipsilateral Babinski sign - damage to lateral corticospinal tracts
How is sacral sparing confirmed in a spinal injury?
Flexion of great toe
PR to assess perianal sensation and anal tone - if maintains sensation/tone then the sacral function is preserved
What does sacral sparing differentiate between in a spinal injury?
complete and incomplete spinal cord injury - prognostic indicator
What is one of the most important investigations in spinal cord injury?
Check FVC regularly - if <500-600mL intubation and ventilation may be required
