Principles of fractures
د0عادل الهنداوي Licture-2
Definition: fracture is a break in structural continuity of bone. If the overlying skin remains intact, the fracture is simple or closed fracture. If not, it is open or compoundfracture, i.e. there is connection between the fracture haematoma and the atmosphere or one of the body cavities, so liable to contamination and infection.
How the fracture happen(types according to the cause)?
1-Traumatic: like fall or road accident(the most common).
2- Repetitive stress: like March fracture in solders (stress #).
3-pathological fracture: Minor trauma or even normal stress can cause fracture if the bone is already weak by some pathology e.g. secondary deposit .
Types of fractures(according to its shape):
1- Complete fracture: may be transverse, oblique, spiral, impacted (the two fragments are driven together)or comminuted fracture (> two fragments).
2- Incomplete fracture: only one side of the cortex is fractured like green stick # in children and incomplete vertebral body fracture in adult.
How fractures are displaced:
1-by the force of injury(whether direct or indirect)
2-by gravity
3- by pull of the muscles attached to the bone
Elements of displacement are:
1- Shift(translation): bone fragments may shifted side way ,backward, forward in relation of distal fragment to proximal fragment .
2- tilt(angulation): there is angle between the fragments
3- twist(rotation): fragment may rotated on its longitudinal axis.
4- overlap or over distraction of bone fragments
How fractures heal? Five stages:
1- Tissue injury and haematomaformation as a result of trauma.
2-inflammation: after 8 hours the cells at bone ends will die ? acute inflammatory reaction with cellular proliferation under the periosteum and inside the medullary canal with growth of new blood vessels. This cellular tissue will bridge the bone ends.
3- Callus formation: now the proliferating cells will differentiate into bone and cartilage cells, and these with time will form the callus
which is immature bone. this process takes about 4 weeks
4- Consolidation: in this stage the immature bone will be changed by bone cells into mature lamellar bone. This process takes about several months.
5- Remodeling: finally the crude bone which bridge the # site will be re
shaped and the medullary canal reformed.
Union: is incomplete repair of a fracture; there is tenderness at the fracture site, and although the fragments move together, but if youtry to angulate the bone it is painful. X-ray will show immature bone.
Consolidation: is complete repair with mature bone. There is no tenderness, no pain, and x-ray show no fracture line and the area is crossed by bone trabecullae( mature bone).
Clinical features of fracture:
History: there is a history of injury and loss of function, pain, swelling, bruising, and deformity. Always look for nerve, vessel and visceral injury.
Examination:
General examination: look for shock, hemorrhage and associated injuries.
Local examination: look for skin damage (open or closed #), test for distal pulse and sensation.
Imaging: X-ray; CT (for fracture vertebra, pelvis, calcaneum); MRI (spine injury) and isotope scan (stress fracture).
Treatment of closed fracture:
-General treatment:
1- first aid.
2- Transport.
3- Treatment of shock, hemorrhage and associated injuries.
-Treatment of the fracture: three steps:
1- Reduction (reduce).
2- Immobilization (hold).
3- Rehabilitation (exercise).
Reduction: means you reduce the fragments into normal position with no shortening, no overlap, no angulations and no rotation. This can achieved by closed or open procedure.
Closed reduction: under general anesthesia, do manipulate the fragments into normal position by reversing the force which causes the fracture.
Open reduction: you surgically open the # site and reduce under direct vision. The indications are:
1- failure of closed reduction.
2- Soft tissue interposition.
3- Intraarticular fractures.
Immobilization: means you prevent displacement of bone ends. There are five types: 1- Casting. Plaster of Paris (pop).
2- Continuous traction.
3- Functional bracing.
4- Internal fixation.
5- External fixation.
Pop casting: is the standard method. Plaster of Paris is hemi hydrated calcium sulphate which reacts with water to form hydrated calcium sulphate with heat production (exothermic reaction). The disadvantages: tight cast, pressure sore and stiffness.
Continuous traction: in oblique or spiral shaft # usually there is displacement because of muscle pull, so by applying continuous traction distal to the #, reduction and holding of the fragments could be achieved. Traction is either through skin or bone:
Skin traction: Elastoplasts is applied to the skin distal to the fracture and hold on with bandage, the cords are used to hold the weight (up to 5 kg otherwise it may slip).
Skeletal traction: Steinmann s pin is inserted transversely through the bone e.g. fracture femur, it is inserted one inch below and one inch behind tibial tubercle. A loop is attached to move freely on the pin and holding the cords that lifting the weight.
Functional bracing: a plastic cast is applied only to the shafts of the bones leaving the joints free to avoid stiffness; the casts are connected by hinges which allow movements in one plane. it should be used only when the fracture started to unite to avoid redisplacement.