General Trauma Master Deck Flashcards
Different classifications of fractures?
Direct trauma, e.g: direct blow, OR indirect trauma (majority), e.g: twisting/bending forces
Partial/incomplete OR complete
High-energy OR low-energy
Describe primary bone healing and when it occurs
Occurs where there is minimal fracture gap (< 1mm), e.g: hairline fractures and when fractures are fixed with compression screws and plates
Bone bridges the gap with new bone
Describe secondary bone healing and when it occurs
Majority of fractures have a gap that needs to be temp. filled to act as a scaffold for new bone
Inv. an inflammatory response with recruitment of pluripotential stem cells, which differentiate
Fracture process of secondary bone healing?
- Fracture occurs and haematoma forms, with inflammation from damaged tissues
- Macrophages and osteoclasts remove debris and resorb the bone ends
- Granulation tissue forms from fibroblasts and new blood vessels
- Chondroblasts form cartilage (soft callus) and osteoblasts lay down bone matrix (collagen type 1)– enchondral ossification
- Calcium mineralisation produces immature woven bone (hard callus)
- Remodelling occurs with organization along lines of stress into lamellar bone
Time period in which soft and hard callus appear?
Soft callus usually forms by 2nd-3rd week
Hard callus takes approx. 6-12 weeks
Requirements for secondary bone healing?
Good blood supply for oxygen, nutrients and stem cells
A little movement/stress (compression or tension)
What factors may result in atrophic non-union?
Lack of blood supply
No movement (internal fixation with fracture gap)
Too large a fracture gap
Tissue trapped in the fracture gap
Smoking may severely impair fracture healing due to vasospasm; vascular disease, chronic ill health and malnutrition also impair fracture healing
Cause of hypertrophic non-union?
Occurs due to excessive movement at the fracture site; there is abundant hard callus formation too much movement gives the fracture no chance to bridge the gap
5 fracture patterns?
- Transverse fractures
- Oblique fractures
- Spiral fractures
- Comminuted fractures
- Segmental fractures
Describe a transverse fracture
Occur with PURE BENDING force (cortex on one side fails in compression and the cortex on the other side in tension)
May not shorten (unless completely displaced) but may angulate or result in rotational malalignment
Describe an oblique fracture
Occurs with a SHEARING force, e.g: fall from height, deceleration; they tend to shorten and may angulate
They can be fixed with an interfragmentary scews
Describe a spiral fracture
Occurs due to TORSIONAL forces; they are most unstable to rotational forces but they can also angulate
Interfragmentary screws can be used
Describe a comminuted fracture
Fracture with 3/more fragments and tend to occur with HIGH-ENERGY injuries (or POOR BONE quality); very unstable and tend to be surgically stabilised
There may be soft tissue damage and periosteal damage with reduced blood supply to the fracture site which may impair healing
How to describe a fracture of long bone?
According to the site of the bone inv.:
• Proximal, middle or distal 1/3rd
OR
• Diaphyseal (shaft), metaphyseal or epiphyseal
How to describe a fracture at the end of a long bone (metaphyseal/epiphyseal)?
Can be:
• Intra-articular - greater risk of stiffness, pain and post-traumatic OA, part. if there is residual displacement resulting in an uneven articular surface
• Extra-articular
What is displacement?
Direction of translation of the distal fragment; described as:
• Anteriorly or posteriorly displaced (in the forearm and hand, volar/palmar and dorsal
• Medially or laterally displaced (ulnar and radial)
Can be estimated with reference to the width of the bone, e.g: 25%; 100% displacement means “off-ended” bone
What is angulation?
Direction in which the distal fragment points towards and the degree of this deformity:
• Medial or lateral (radial or ulnar; in the lower limb, varus and valgus are used)
• Anterior or posterior (volar or dorsal)
Clinical signs of a fracture?
- Localised bony tenderness that is marked (not diffuse mild tenderness)
- Swelling
- Deformity
- Crepitus (bone ends grate in an unstable fracture)
Useful rule when deciding whether to X-ray the lower limb for a fracture?
Inability to weight-bear
Steps in the assessment of an injured limb?
- Open/closed
- Distal neurovascular status (pulses, CRT, temp, colour, sensation, motor power)
- Check for compartment syndrome
- Assess the status of the skin and soft tissue envelope
Methods of Ix for a fracture?
X‐ray (must have 2 views) - usually an AP and lateral view; oblique views can be useful for complex shaped bones (e.g: scaphoid, acetabulum, tibial plateau)
Tomogram (historic)
CT scan - for complex bones and for assessment of articular damage
MRI - for occult fractures that are suspected despite a normal X-ray
Technetium bone scans - to detect stress fractures that may not show up on X-ray until a hard callus forms
Initial Mx of a long bone fracture?
Analgesia (IV morphine), splintage/immobilisation of the limb and Ix (X-rays)
Reduction is performed before X-ray if:
• Fracture is obviously grossly displaced
• Obvious fracture-dislocation
• Risk of skin necrosis from excessive pressure
What does splintage or immobilisation involve?
- Temporary plaster slab (AKA backslab)
- Sling
- Orthosis
- Thomas splint (for femoral shaft fractures)
Definitive fracture Mx for different types of fractures?
Undisplaced, minimally displaced and minimally angulated fractures that are stable:
• Non-operative Mx with a period of splintage/immobilisation followed by rehab
Displaced OR angulated fractures where the position is unacceptable:
• Reduction under anaesthetic; closed reduction and cast application can be used with serial X-rays to ensure no loss of position
• Unstable injuries can have surgical stabilisation
Tools used for surgical stabilisation of an unstable injury?
- Small percutaneous wires (K-wires) for small fragments
- Screws OR plates and screws
- IM nails
- External fixation
Definitive Mx of an extra-articular diaphyseal fracture?
Open reduction and internal fixation (ORIF) using plates and screws
Aim is primary bone healing
When should ORIF be avoided?
- Too much soft tissue swelling
- Blood supply to the fracture site is tenuous (high-energy)
- If ORIF may cause extensive blood loss, e.g: femoral shaft
- Where plate fixation may be prominent, e.g: tibia
Alternative to ORIF?
Closed reduction and indirect internal fixation, with an IM nail; aim is functional reduction and stable fixation allowing micromotion required for secondary bone healing
Another alternative is external fixation; aim is secondary bone healing
Risks of external fixation?
Pin site infection and loosening
Definitive Mx of a displaced intra-articular fracture?
Anatomic reduction with rigid fixation with ORIF
Fractures of a joint with a predictable poor outcome can undergo joint replacement or arthroidesis
Problems with treatment of fractures in elderly patient?
May have co-morbidities, osteoporosis and dementia; they have a higher risk of surgical complications, failure of fixation and failure to rehab satisfactorily
Tend not to have as high a functional demand and so more likely to be treated non-operatively
Early local complications of fractures?
- Compartment syndrome
- Vascular injury with ischaemia
- Nerve compression/injury
- Skin necrosis
Early systemic complications of fractures?
- Hypovolaemia and shock
- Fat embolism
- Acute renal failure
- ARDS, SIRS and MODS
Late local complications of fractures?
- Stiffness and loss of function
- Chronic Regional Pain Syndrome (CRPS)
- Infection
- Non-union
- Malunion
- Volkmann’s ischaemia contracture
- Post-traumatic OA
- DVT
Late systemic complications of fractures?
PE (tends to occur several days-weeks after injury but may occur within a day)
Describe compartment syndrome
Groups of muscles are bound in tight fascial compartment with limited capacity for swelling
Bleeding and inflammatory exudate cause pressure rise and compression of the venous system, resulting in congestion within the muscle; secondary ischaemia occurs as arterial blood cannot supply the congested muscle, so muscle ischaemia occurs
Symptoms and signs of compartment syndrome?
Pressure can compress nerves, causing paraesthesiae and sensory loss
Cardinal clinical signs:
- Increased pain on passive stretching of the inv. muscle
- Severe pain outwith the anticipated severity in the clinical context (disproportionate)
Limb is tensely swollen and muscle is tender to touch
Loss of pulses is a feature of end-stage ischaemia (late diagnosis)
Treatment of compartment syndrome?
Removal of any tight bandages can cause temporary relief
Emergency fasciotomy; the open wound is left for a few days before secondary closure (may require split skin grafting)
Complications of untreated ischaemic muscle in compartment syndrome?
Necrosis occurs, resulting in fibrotic contracture (AKA Volkmann’s ischaemia contracture) and poor function
Types of nerve injury?
- Neurapraxia
- Axonotmesis
- Neurotmesis
What is neurapraxia?
Nerve has a temporary conduction defect from compression/stretch and resolve over time with full recovery (up to 28 days)
What is axonotmesis?
Occurs due to a sustained compression or stretch or from a higher degree of force
Nerve remains in continuity and the internal structure (endoneurial tubes) remains intact, the long nerve cell axons distal to the point of injury (AKA Wallerian degeneration); longer peripheral nerve thus take longer to recover
Ix and prognosis of axonotmesis?
Recovery is variable and full power/sensation may not be achieved; it can be predicted by nerve conduction studies (from around a month from the time of injury)
What is neurotmesis?
Complete transection of a nerve (rare in closed injuries but may occur in penetrating injuries)
No recovery occurs unless the affected nerve is surgically repaired
General rule with nerve injuries assoc. with fracture (or dislocation)?
Usually resolve with time and they do not indicate surgical exploration, unless there is evidence of nerve entrapment within the fracture, causing severe neuralgic pain
If a nerve injury occurs after fracture manipulation, assume that the nerve is trapped in the fracture site
Treatment option for poor recovery from axonotmesis or neurotmesis?
Nerve grafting, using an expendable cutaneous nerve can help
Tendon transfers to recruit muscles with intact nerve supply and altering their mechanics, by changing their insertion can improve function
Injuries that are characteristically assoc. with particular nerve injuries?
Colles fracture - acute median nerve compression/carpal tunnel syndrome
Anterior dislocation of the shoulder - axillary nerve palsy
Humeral shaft fracture - radial nerve palsy (in spiral groove)
Supracondylar fracture of the elbow - median nerve injury (usually anterior interosseous branch)
Posterior dislocation of the hip - sciatic nerve injury
“Bumper” injury to lateral knee - common peroneal nerve palsy
Complications of vascular injuries?
Distal limb ischaemia risks subsequent amputation
Haemorrhage from arterial/venous injury may result in hypovolaemic shock
Certain injuries have a higher risk of concomitant vascular injury
Risks assoc. of different types of fracture?
- Knee dislocations risk popliteal artery injury
- Paediatric supracondylar fracture of the elbow risks brachial artery injury whilst shoulder trauma can result in axillary artery compromise
- Pelvic fractures can be assoc. with life-threatening haemorrhage, from arterial/venous bleeding
Signs of reduced distal circulation?
- Reduced or absent pulses
- Pallor
- Delayed capillary refill
- Cold to touch
Mandates urgent vascular surgery review and surgical Mx
Ix and treatment vascular injury?
Urgent angiography may help localise the site of arterial occlusion
Temporary restoration of circulation using a vascular shunt or repair (bypass graft or stent)
Skeletal stabilisation with internal/external fixation should be performed to protect the repair from shearing force
Ongoing haemorrhage from arterial injury in the pelvis can be controlled angiographic embolisation
Causes of skin and soft tissue problems with fractures?
With higher energy injuries or with fragile skin, e.g: due to age, steroids, rheumatoid arthritis
Injury may jeopardise the viability of the overlying skin; a protruding spike of bone/ tension on the skin from deformity can lead to devitalisation and necrosis with skin breakdown
Signs and symptoms of skin and soft tissue problems?
Tenting of the skin and “blanching” (fracture causes excessive pressure on the skin)
Treatment of fractures with skin and soft tissue problems?
Reduced as an emergency (under analgesia +/- sedation) to avoid necrosis
Describe de-gloving
Shearing force on the skin can result in avulsion of the skin from its underlying blood vessels
Underlying haematoma may also increase pressure on the skin occluding capillaries
Symptoms and signs of de-gloving?
Skin will not “blanch” on pressure and may be insensate
Describe fracture blisters
Occur due to inflammatory exudates causing lifting of the epidermis of the skin (much like a burn)
Treatment of skin and soft tissue complications of fractures?
Surgical wound through swollen and contused skin and soft tissue is not advisable as the wound may not be closed (leaving a route for potential infection)
OR
Excessive tension on the wound may lead to necrosis and wound breakdown
Indirect methods of stabilisation may be appropriate
Ix for assessing fracture union?
Bridging callus may be seen on X-ray but, if there is doubt, CT scans can confirm
Not all fractures need to have radiographic evidence of fracture union; many fractures, part. extra-articular cancellous bone fracture, are expected to heal and do not routinely require follow-up X-rays
Symptoms and signs of fracture healing?
- Resolution of pain and function
- Absence of point tenderness
- No local oedema
- Resolution of movement at fracture site
Clinical signs of non-union?
- Ongoing pain and oedema
* Movement at the fracture site
Slowest healing bones in the body?
Tibia typically takes ~16 weeks and sometimes over a year to unite
Femoral shaft fractures also take 3-4 months to heal
Which fractures heal faster: metaphyseal or cortical?
Metaphyseal fractures tend to heal more quickly
What is a delayed union and potential causes?
Delayed union is a fracture that has not healed within the expected time
Infection can result in delayed union and, if diagnosed, healing can occur; however, if the infection is suppressed with antibiotics, the fracture may go on to an infected non-union
Types of non-union and their causes?
Hypertrophic non-union can occur due to:
• Instability and excessive motion at the fracture site
Atrophic non-union can occur due to: • Rigid fixation with a fracture gap • Lack of blood supply to the fracture site • Chronic disease • Soft tissue interposition
Both types may also be caused by infection
Which fractures are part. prone to problems with healing due to poor blood supply?
Scaphoid waist fractures
Fractures of distal clavicle
Subtrochanteric fractures of the femur
Jone fracture of the 5th metatarsal
Some intra-articular fractures may not unite due to synovial fluid inhibition of healing if a fracture gap exists, e.g intracapsular hip fractures, scaphoid fractures
Prophylaxis of DVT?
Usually, LMWH is given to all “at-risk” patients
Suspected DVT require requires duplex scanning and anti-coagulation
What is fracture disease?
Stiffness and weakness due to the fracture and subsequent splintage in cast
Treatment of fracture disease?
Most cases resolve with time and may be helped with physio
Fractures prone to AVN?
Fractures of the femoral neck, scaphoid and talus
Treatment of AVN?
Surgical Mx in the form of:
• THR for the hip or arthroidesis
• Arthrodesis
Causes of post-traumatic OA?
Intra-articular fracture, ligamentous instability or fracture malunion
Treatment of post-traumatic OA?
Analgesia, bracing/splinting, arthrodesis or joint replacement
What is complex regional pain syndrome (CRPS)?
Heightened chronic pain response after injury; it can be caused by a peripheral nerve injury (type 2 CRPS) or not (type 1 CRPS)
Characteristics of CRPS?
- Constant burning or throbbing
- Sensitivity to stimuli not normally painful (allodynia), inc. cold or light touch
- Chronic swelling
- Stiffness
- Painful movement
- Skin colour changes
Mx of CRPS?
Analgesica, anti-depressants (amitriptyline), anti-convulsants (gabapentin) and steroids
TENS machines
Physio
Lidocaine patches
Sympathetic nerve blocking injections
Fixation methods of an infected fracture?
Can still unite if the infection is suppressed; for acute infections:
• Antibiotic therapy with/without surgical washout may be adequate
For infections present >few weeks:
• Antibiotic suppression but the metalwork will need later removal
If the infection cannot be suppressed and becomes too problematic (sepsis, discharging sinus):
• Surgery is required with removal of all implants and debridement of infected bone
For medullary infection, from an infected IM nail, the medullary canal can be reamed out and a new nail implanted; alternatively, an external fixator can be applied to give stability (also approp. for infected non‐union of a plate and screw fixation)
Causes of open fractures and types?
Inside-out injury - either due to a spike of fractured bone from within puncturing the skin
Outside-in injury - laceration of the skin from tearing/penetrating injury
Factors that increase the risk of infection of an open fracture?
Higher-energy injury
Amount of contamination
Delay in appropriate treatment
Problems with wound closure
Classification system for open fractures?
Gustilo classification describes the: • Degree of contamination • Size of the wound • Whether the wound will be able to be closed or require plastic surgery • Presence of an assoc. vascular injury
Initial Mx of open fractures?
IV broad-spectrum antibiotics, typically:
• Flucloxacillin - cover gram +ve organisms
• Gentamicin - cover gram -ve organisms
• Metronidazole - cover anaerobes if there is soil contamination
Sterile/antiseptic soak dressing should be applied to the wound to prevent further contamination, before the fracture is splinted
Surgical Mx of open fractures?
Prompt surgical debridement and stabilisation with internal/external fixation; wound can be closed primarily if:
• No gross contamination and all remaining skin and muscle is viable
• Closure can occur with no undue tension on skin edges
If doubt over soft tissue viability, or if the wound is heavily contaminated, safer to leave the wound open (allow ongoing infection to drain out) and do further debridement in 48 hours (necrotic tissue will be obvious now)
Why is there an infection risk with unstable fractures?
May produce haematoma, which acts as a culture medium for bacteria and can cause additional necrosis
Alternatives if a wound cannot be closed primarily?
Either skin grafting, local flap coverage or free flap coverage
Tissues that readily accept a skin graft?
Muscle, fascia and granulation tissue, as can paratenon and periosteum
Skin graft does not take on?
Bare tendon, bone or any exposed metalwork; may also not take on fat, due to poor vascularisation
Treatment of mangled extremiry?
In some cases, may be wiser to do an early amputation to produce a more functional outcome and avoid multiple surgeries
Treatment of a dislocation?
REDUCED AS SOON AS POSSIBLE, mostly with closed reduction under sedation and analgesia
Delayed presentation, e.g: alcoholics, increases risk of requiring open reduction and recurrent instability
Causes of dislocation?
Significant trauma
Hypermobility, inc. Ehlers-Danlos syndrome and Marfan’s
Some can voluntarily dislocate joints
Injuries assoc. with dislocation?
Tendon tears
Nerve and vascular injury
Compartment syndrome
Treatment of fracture-dislocations?
Closed reduction
ORIF may be used if:
• Closed reduction cannot be achieved
• Bony fragment prevents congruent reduction
• Joint is very unstable
Grading of ligament ruptures?
Grade 1 (sprain)
Grade 2 (partial tears)
Grade 3 (complete tear)
Mainstay treatment of most soft tissue injuries?
Rest
Ice
Compression
Elevation
Reduces initial swelling; follow this with early movement to prevent movement
Treatment of complete ligament ruptures?
May result in joint instability - repair, tightening (Advancement) or graft reconstruction
Treatment of complete tearing of tendons that are fundamental for function?
E.g: quadriceps, patellar tendons
Surgical repair
Some can be treated conservatively, e.g: complete tearing of Achilles tendon, rotator cuff, long head of biceps brachii, distal biceps) but repair can restore function
Treatment of divided tendons?
May occur with a penetrating incised wound, e.g: flexor and extensor tendon injuries in the hand and wrist are part. common and usually require surgical repair
Typical presenting features of septic arthritis?
Acute onset of severely painful red, hot, swollen and tender joint
Severe pain on any movement
Causes of septic arthritis?
In most cases, organism spreads via blood or from infection of adjacent tissues
May be a Hx of direct, penetration of a joint, e.g: “fight bite” wound from a punching injury and penetration of a tooth OR a rose thorn injury from gardening
May occur after intra-articular surgery
Septic emboli from endocarditis, part. if >1 joint or bone is inv.
Complications of untreated septic arthritis?
Bacteria can irreversibly damage hyaline articular cartilage within day; there can be chronic arthritis damage
Groups of people that are most prone to septic arthritis?
Young and elderly
PWIDs and immunocompromised patient
Neonates and infants have some intra-capsular metaphyses and septic arthritis can evolve from metaphyseal osteomyelitis
Most common bacterial causes of septic arthritis?
- Staph. aureus (most common in adults)
- Streptococci (2nd most common)
- H. influenzae (used to be most common cause in children but reduced due to vaccine)
- Neisseria gonorrhea (young adults)
- E. coli (elderly, PWIDs and the seriously ill)
Ix for septic arthritis?
Aspiration before antibiotics are given (a single dose can cause a falsely -ve gram stain and culture); looking for frank pus aspiration or a +ve gram stain
Treatment of septic arthritis?
Surgical washout either via open surgery or using arthroscopic techniques; open washout is best to decrease bacterial load throughout the joint
Response to treatment is based on clinical findings and serial CRP
