General Trauma - Fractures Flashcards
what is a fracture?
medical term for a break in the bone
- can be complete or incomplete
what is primary bone healing?
method of bone healing when fracture gap is small (<1mm), hairline fractures and fractures which are compressed with plates and screws
bone simply bridges the gap with new bone formed by osteoblasts
what is secondary bone healing?
inflammatory response temporarily fills a larger gap with pluropotential stem cells at the fracture site to act as a scaffold for new bone to be laid down
what is the process of secondary bone healing?
- fracture occurs
- haematoma occurs 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) - 2-3 weeks
- osteoblasts lay down bone matrix (type 1 collagen) = echondral ossification
- calcium mineralisation produces immature woven bone (hard callus) - 6-12 weeks
- remodelling occurs with organisation along lines of stress into lamellar bone
what is required for secondary bone healing to take place?
good blood supply for oxygen, nutrients and stem cells
a little movement/stress
nutrition
not smoking
can result in atrophic non union or hypertrophic non union without
what are the 5 patterns of fracture?
transverse - due to bending force
oblique - due to shearing force (fall from height, deceleration)
spiral - due to torsional, rotational forces
comminuted - due to high energy injury
segmental - bone fractured in 2 separate places
what are the features of each fracture type?
transverse - can angulate or cause rotational malalignment
oblique - tend to shorten and angulate, fixed with screw
spiral - rotational instability and can angulate, screws can be used
comminuted - 3 or more fragments, soft tissue swelling, periosteal damage, reduced blood supply, unstable, needs surgery
segmental - very unstable and need long rods or plates
how can a fracture of a long bone be described?
site - proximal, distal, middle
type of bone - diaphyseal, metaphyseal, epiphyseal
intra/extra-articular
displacement
what does displacement of a fracture depend on?
translation
angulation
rotation
how can translation of a distal fragment be describe?
anteriorly or posteriorly displaced
medially or laterally translated
- terms replaced by volar/palmar and radial/ulnar when in the hand
degree estimated with reference to width of bone
what is a 100% displacement of fracture known as?
off ended fracture
what is angulation?
the direction in which the distal fragments points towards and the degree of this deformity
how is angulation described?
medial/lateral and anterior/posterior
radial/ulnar and dorsal/volar in upper limb
varus/valgus and in lower limb
measured in degrees from the longitudinal axis of diaphysis of long bone
why is angulation important?
gives info about direction of forces, reversed direction of forces required to reduce the fracture
can lead to deformity, loss of function and post traumatic OA
what is rotational malalignment?
rotation of the distal fragment relative to the proximal fragment
unstable and needs to be corrected
what are the clinical signs of a fracture?
localised bony tenderness
swelling
deformity
crepitus - from bone ends grafting with unstable fracture
general rule for X ray of possible fracture?
if patient cant weight bear on an injured lower limb - request an X ray
how do you assess an injured limb?
open or closed
neurovascular status
presence of compartment syndrome
assess skin and soft tissue envelope
how can a fracture be investigated?
radiograph - 2 views always requested (AP and lateral/sometimes oblique)
tomogram - moving x ray, used for mandibular fractures
CT - complex bones/fractures, show articular damage, surgical planning
MRI - if normal x ray
Technetium bone scans - stress fractures (don’t show in X ray)
describe the initial management of a long bone fracture
clinical assessment
analgesia
splintage/immobilization (backslab, sling, orthosis, Thompson splint)
investigation
reduce before X ray if grossly displaced or risk to skin
describe definitive management of undisplaced or minimally displaced/angulated fractures
non-operative with splintage or immobilization then rehab
how are displaced or angulated fractures managed definitivey
reduction under anaesthesia
closed reduction and cast application
surgical stabilisation (plates, screws, pins, nails, external fixation etc)
how is an unstable extra-articular diaphyseal fracture managed?
can be fixed with ORIF using plates and screws
when should ORIF be avoided and what is used instead in such a case?
soft tissue swelling
high energy blood supply
if ORIF would cause blood loss (femoral shaft)
if plate fixation at the site would be prominent (tibia)
instead closed reduction and indirect internal fixation with intramedullary nail
what methods of fracture healing cause primary and secondary healing?
ORIF = primary
closed reduction with intramedullary nail = secondary
external fixation = secondary
how are displaced intra-articular fractures managed?
require anatomic reduction and rigid fixation by way of ORIF with wires, screw and plates
how are fractures involving a joint with predicted poor outcome managed?
joint replacement or arthrodesis
why are older patients often treated non-operatively?
co morbidities
higher surgery complication risks
less satisfactory rehab results
lower functional demand
how can fracture complications be categorised?
early/late
local/systemic
what are some early local complications?
compartment syndrome
vascular injury - ischaemia
nerve compression
skin necrosis
what are some early systemic complications?
hypovolaemia fat embolism shock ARDS renal failure multi organ dysfunction systemic inflammatory response syndrome death
what are some late local complications?
stiffness loss of function chronic pain infection non union mal union volkmanns ischaemic contracture OA DVT
what is the main late systemic complication?
PE
what are the symptoms of compartment syndrome?
severe pain on passive stretching of involved muscle
severe pain more than expected in clinical context
paraesthesia and numbness
swelling
tenderness
loss of pulse at end stage
management of compartment syndrome?
remove any tight bandages
emergency fasciotomy - leave open for a few days then secondary closure/skin graft
complication of compartment syndrome?
volkmanns ischaemic contracture
ischaemic muscle with necroes resulting in fibrotic contracture
what can happen to vessels in fractures?
stretched compressed torn transected partial tear > thrombosis > arterial occlusion
give some possible complications of vascular injury
ischaemia - amputation
hypovolaemic shock
what injuries are most likely to cause vascular injury?
penetrating injury knee dislocation paediatric supracondylar fracture shoulder trauma pelvic fractures
how can temporary restoration of circulation be achieved?
vascular shunt
vascular repair with bypass graft or endoluminal stent
skeletal stabilisation with internal/external fixation to protect repair
what is done for an ongoing haemorrhage from artery injury in pelvis?
angiographic embolization
what skin sign can indicate that an emergency reduction of a fracture is needed and why?
tenting of skin and blanching
protrusion through skin
to avoid subsequent necrosis
what causes degloving and what are the features of this?
shearing force on the skin causing avulsion of the skin from its blood vessels
skin wont blanch on pressure and have no sensation
can have an underlying haematoma increasing pressure on skin and occluding capillaries
what is a fracture blister?
inflammatory exudate causes lifting of the epidermis of the skin (like burn)
why is surgery not preferred which soft tissue is swollen?
wound may not be able to close or if it does it may be very tight and the tension can lead to necrosis and wound breakdown
what are the signs of fracture healing?
resolution of pain and function
absence of point tenderness
no local oedema
resolution of movement at fracture site
what are the signs of non union?
ongoing pain and oedema
movement at fracture site
bridging callus seen on imaging
what is delayed union and what can cause it?
fracture that doesn’t heal within expected time
can be caused by infection
what are the 2 types of non-union and what causes them?
hypertrophic - instability, excessive motion, infection
atrophic - rigid fixation with gap, poor blood supply, chronic disease, soft tissue interposition, infection
name some fractures which are prone to non-union?
scaphoid distal clavicle subtrochanteric femur jones fracture some intra-articular fractures
what is fracture disease?
stiffness and weakness due to the fracture and subsequent splintage
fixed with physio
bones prone to AVN? how are they managed?
femoral neck
scaphoid
talus
THR or arthrodesis
what type of fracture causes post traumatic OA?
intra-articular
fracture malunion
ligamentous instability
what is chronic regional pain syndrome?
heightened chronic pain after injury constant burning/throbbing sensitivity to non-painful stimuli chronic swelling stiffness painful movement skin colour changes
what can cause CRPS and how is it managed?
Type 1 = unknown
Type 2 = peripheral nerve injury
management = pain relief (analgesics, nerve block, antidepressants, anti epileptics)
how does infection affect fracture healing?
slows it down when active
fracture can unite when infection is suppressed
how is infected fracture fixation managed?
antibiotics and surgical washout
if present for longer than a few weeks - metal needs removed
if infection cant be suppressed - remove all implants and debride infected bone
management of medullary infection?
medullary canal reamed out and a new nail implanted
or
external fixator
management of infected non-union of a plate and screw fixation?
external fixator
