Week 5 CORTEXT - Fractures Flashcards
Transverse fractures
Occur with pure bending force where the cortex on one side fails in compression and the cortex on the other side in tension.
Transverse fractures may not shorten (unless completely displaced) but may angulate or result in rotational malalignment
Oblique fractures
Occur with a shearing force (e.g. fall from height, deceleration.)
Oblique fracture patterns have the benefit of being able to be fixed with an interfragmentary screw. Oblique fractures tend to shorten and may angulate
Spiral fractures
Occur due to torsional forces. Again interfragmentary screws potentially can be used. Spiral fractures are most unstable to rotational forces but can also angulate
Comminuted fractures
fractures with 3 or more fragments.
Comminution is generally a reflection of a higher energy injury (or poor bone quality) and there may be substantial soft tissue swelling and periosteal damage with reduced bloody supply to the fracture site which may impair healing. Comminuted fractures are very unstable and tend to be stabilised surgically.
Segmental fractures
Occurs when bone is fractured in two separate places. These injuries are very unstable and require stabilisation with long rods or plates.
Angulation
Describes direction in which the distal fragment points towards and the degree of this deformity.
Medial (varus), lateral (valgus), anterior, posterior.
Can be measured in degrees from the longitudinal axis of diaphysis of long bone
Clinical signs of fracture
Localised bony tenderness (not diffuse mild tenderness)
Swelling
Deformity
Crepitus
Assessment of injured limb includes:
open or closed injury
distal neurovascular status
compartment syndrome
status of the skin and soft tissue envelope
Investigations
Radiographs Tomogram - moving x-ray CT MRI Technetium bone scan
Initial management
clinical assessment, analgesia, splintage/immoblisation and investigation
Definitive fracture management
Depends on bone:
Undisplaced, minimally displaced and minimally angulated fractures which are stable = non-operatively with splintage and immobilsation and then rehab.
Displaced or angulated fractures = closed reduction and cast application
Unstable injuries = surgical stabilisation
Complications
Early local - compartment syndrome, vascular injury with ischaemia, nerve compression or injury and skin necorisis
Early systemic = hypovolaemia, fat emboli, shock, ARDS, acute renal failure, SIRS, multi-organ dysfunction syndrome and death
Late local = stiffness, loss of function, chronic regional pain syndrome, infection, post traumatic osteoarthritis, DVT
Late systemic = pulmonary embolism
Compartment syndrome
Requires urgent fasciectomy
Nerve injuries
Neurapraxia
Axonotmesis
Neurotmesis
Neurapraxia
Temporary conduction defect from compression or stretch. Resolves over time with full recovery (can take 28 days)
Axonotmesis
sustained compression or stretch or from higher degree of force.
Nerve remains in continuity and internal structure intact, but the long nerve cell axons distally to point of injury die in process known as Wallerian degeneration.
Recovery is long for long nerves, regenerates at 1mm per day
Recovery is also variable and full power or sensation may not be achieved.
Neurotmesis
complete transection of a nerve and is rare in closed injuries but can occur in penetrating ones.
No recovery without surgery, never get full recovery
Recovery variable.
Colles fracture
acute median nerve compression/carpal tunnel syndrome
Anterior dislocation of shoulder
axillary nerve palsy
humeral shaft fracture
radial nerve palsy (in spinal groove)
supracondylar fracture of elbow
median nerve injury (usually anterior interosseous branch)
Posterior dislocation of hip
sciatic nerve injury
“bumper” injury to lateral knee
common peroneal nerve palsy
symptoms and signs of fracture healing
resolution of pain and function
absence of point tenderness
no local oedema
resolution of movement at fracture site
Symptoms and signs of fracture NOT healing
ongoing pain
ongoing oedema
movement at fracture site
bridging callus seen on x-ray (CT better option to differentiate)
How long does a tibia take to heal?
typically 16 weeks and sometimes over a year to unite
How long does a femoral shaft take to heal?
Typically 3-4 months to heal
What is a delayed union fracture?
one that has not healed within the expected time.
Infection can result, and has to be suppressed with antibiotics.
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 bloody supply, chronic disease or soft tissue interposition
