Loco orthopaedics Flashcards
Most common fracture
<75 = Colles >74 = hip
Comminuted fracture
2 or more bone pieces
Places where avulsion fractures can occur
Ischial tuberosity = hamstring
Medial epicondyle = flexors and pronators
ASIS = sartorius
AIIS = rectus femoris
Where are bust fractures most common?
Thoraco-lumbar junction
Types of stress fracture
Fatigue = abnormal stress on normal bone Insufficiency = normal stress on abnormal bone
Stage 1 of bone healing
Fracture haematoma
Blood clot forms
low pH and hypoxia
Recruitment of inflammatory cells
Stage 2 of bone healing
Soft callus New capillaries remodel haematoma Inflammatory cells remove dead bone Fibroblasts and chondrocytes begin to produce fibrous tissue = soft callus Osteoblasts begin to enter area
Stage 3 of bone healing
Hard callus
Osteoblasts produce woven bone to replace soft callus
Stage 4 of bone healing
Remodelling
Woven bone is remodelled into lamellar bone
Blood loss from fractures
Tib/fib = 500ml Femur = 500ml Pelvic = 2000ml
Nerve injuries as a result of trauma
Neurapraxia = nerve compression without axonal disruption Axonotmesis = axoplasmic disruption but endoneurial sheath intact Neurotmesis = axon and axon sheath disrupted
Absolute indications for ORIF
Displaced intra-articular fractures Open fractures Fractures with vascular injury or compartment syndrome Pathological fractures Non-union
Relative indications for ORIF
Loss of position with closed reduction
Poor functional result
Displaced fracture with poor blood supply
Radiological union
When 3 out of 4 cortices are healed
Signs of fat embolus
Hypoxaemia
Petechial rash
Neurological signs –> snowstorm appearance on MRI
Compartment syndrome pressures
Normal = 0-10mmHg
Capillary blood flow compromised = >20mmHg
Nerve and muscle fibre damage = >30-40mmHg
Hybrid and reverse hybrid hip replacement
Hybrid = cemented stem and cement less cup
Reverse hybrid = cementless stem and cemented cup
Characteristics of body part used for tendon transfer
Under voluntary control
Expendable
Adequate tendon length
Be innervated to a different nerve to the one that was damaged
When is tendon transfer done?
Nerve palsy
What muscle imbalances occur in cerebral palsy?
Quadriceps > hamstrings
Plantarflexors > dorsiflexors
What can be used for ACL reconstruction?
Patella-ligament-tibia Hamsting tendon (semitendinosis, gracilis)
Define delayed healing
Failure in 1.5x normal time
Define non-union
Failure in 2x normal time
Sites of autograft harvesting
Iliac crests
Ribs
Fibula
Mandible
Properties of bone grafts
Osteoconduction = scaffold for cells Osteoinduction = molecules in graft induce neighbouring cells to become osteoblasts Osteopromotion = graft material enhances osteoinduction (but does not induce osteoblast differentiation itself) Osteogenesis = cells in the graft are capable of producing bone
What pathologies can cause toe walking?
Cerebral palsy
Duchenne muscular dystrophy
Nervous system problems
Risk factors for talipes equinovarus
Breech presentation
CT disorders
Poly/oligohydramnios
Family history
Treatment of talipes equnovarus
Ponseti method
Risk factors for CHD
Breech delivery
First born child
Presentation of CHD
Asymmetrical leg length
Uneven thigh and gluteal folds
Leg turned into external rotation
Limited abduction
Diagnosis of CHD
Barlow = adduction Ortolani = abduction Galeazzi = leg length
What should normal alpha angle be on ultrasound
> 60
Hilgenreiner’s line
Between inferior aspects of triradiate cartilages
Acetabular angle
<30 degrees
Gets smaller with age
CHD treatment
Pavlik harness
Hip spica
Closed reduction
Corrective osteotomy
Stages of Perthes disease
Necrosis
Fragmentation
Re-ossification
Remodelling
SUFE presentation
Limited internal rotation
Risk factors for SUFE
Obesity
Hypothyroidism
Early or late puberty
Klein’s line
Along superior border of femoral neck
Should intersect femoral head
Blount’s disease
Medial tibia growth problem
Leads to varus deformity
Kohler’s disease
Osteochondrosis disorder affecting the foot joints
