General Principles of Fractures Flashcards
Define dislocation
Complete loss of contact between articular surfaces of a joint.
Define subluxation
Some contact, but no longer congruous
What is required for bone to heal?
Intact fracture haematoma and controlled micro-movement
Name the 4 stages of bone healing
Inflammation
Soft callus
Hard callus
Remodelling
What is present in a fracture haematoma? and what stage of the fracture healing is it present?
Stage 1: Inflammation
Fibrin clot
Polymorphs
Platelets
Monocytes
Later: Fibroblasts, osteoprogenitor cells, vascular ingrowth
Describe the soft callus
Bony fragments united by fibrous or cartilaginous tissue
Both ends no longer freely movable, though angulation is still possible
Describe the hard callus
Mineralisation of cartilage
Osteoblasts convert cartilaginous tissue → woven bone
External callus
Name indications for internal fixation (5 in total)
Displaced intra-articular fractures
Fractures with tenuous blood supply
Multiple injuries
More than one fracture in single limb
Pathological of long bones
What is the classic triad for fat embolism?
Respiratory
Neurological
Petechial Rash
What is compartment syndrome and what are the signs?
Muscle swelling within a closed osseo-fascial compartment → increased pressure → capillary ischaemia and death
Signs:
Pain on passive stretch of muscle
Pain out of proportion to injury
Pins and needles, pulselessness are signs but manifest too late
What would the radiographs show for delayed union?
(two marks)
Bone resorption
Restricted/poor quality callus
Malunion or non-union are typical for the tibia which is bad at healing (extra-osseus blood supply)
Define Hypertrophic non-union and how would you treat it?
Inadequate stability but bone ends viable → excessive callus
Treatment: Achieve stability
Define atrophic non-union and how would you treat it?
No evidence of cellular activity → both ends narrow rounded and porotic
Treatment: remove fibrous tissue from both ends up to healthy bone, rigid stabilisation, graft area around fracture
Define a pathological fracture
Fracture occuring following minimal stress through abnormal bone
How do you treat open fractures?
Within 6 hours:
Thorough/repeated debridement
Skeletal stabilisation
WIthin 72 hours:
Early skin cover and rehabilitation after
Define the following fractures:
Greenstick
Buckle
Plastic deformity
Physeal injury
Greenstick = angulated, intact inner side of curve
Buckle = bump in bone
Plastic deformity = like plastic ruler bending, remains bent after force removed
Physeal injury = fracture through zone of provisional calcification, growing cells remain with epiphysis (Salter Harris 2 most common)
What are the differences between adult and child bone?
Anatomically
In terms of the periosteum
Biomechanically
Anatomically = bone may heal curved, but will eventually straighten - remodelling ability
Periosteum = thick, metabolically active
Biomechanically = increased collagen:mineral content, more porous and elastic
Also ligaments are stronger than bone, so physis is a weak link
How would you treat an intra-articular fracure that is displaced?
Open reduction, as it is intra-articular, the joint surface requires repairing to reduce risk of secondary OA.
Also stable fixation to allow early movement to eliminate joint stiffness
How would you treat a pubic ramus fracture that is minimally displaced?
Does not require reduction if minimally displaced. Pelvic ring is stable for retention.
Symptomatic treatment and early mobilisation is appropriate.
