A. By quality of bone in relationto load( Fractures occur when the load to which they are subjected exceeds their intrinsic strength) FRACTURE TYPE BONE STRENGTH LOAD
Traumatic fracture of 2nd lumbar vertebra and vertebral luxation at the site of injury
Greenstick fracture :- It a type of simple fracture in which only one side of the bone is broken while the opposite side bent. Occurs in children . It resembles the breaking of a green tree branch, hence the name.
B. By Direction of force 1) Compression fracture :- If the load applied along the length of a bone exceeds that of its strength then it may collapse into itself . Common in elderly if bones are osteoporotic and so are less able to resist a heavy load . The bone will be shortened and may also be angulated.
2) Avulsion ordistraction fracture Here the two fragments of bone are pulled apart. It occurs when a tendon is torn of it attachment to bone and take a fragment of bone with it. Common where strong muscles insert into small bones.e.g patella ( quadriceps ms.) ,
3) Spiral fractures :- If a long bone is twisted along its axis a spiral fracture may result. the tibia is particularly susceptible to spiral fracture when the foot is firmly fixed to ground and player’s body continues to twist.
4) Transverse fracture :- If a long bone is bentalong its long axis then a transverse fracture may result.
5) Butterfly fracture :-If a bone is struck a direct blow,it is common for a more complex fracture to result where two break lines spread out obliquely from point of contact of theblow, producing a free- floating ‘Butterfly’ fragment between the two fracture.
6) Comminuted fracture :- Occur when a large amountof energy is dissipated into a bone. bone breaks into fragmentswhich may impact into eachother or separate and become displaced.
C. By anatomical site :-Epiphyseal fracture Articular fracture ( fracture into joint)
Salter Harris classification of epiphyseal fractures :- Grade 1 :- In this case there is small crack along the metaphyseal side of epiphyseal plate. this side is made up of dying chondrocytes and ossifying cartilage. does not affect the blood supply to the epiphyseal plate nor does it affect the anatomy of the germinal layer Heals quickly
Grade 2 Here the fracture line travels along the metaphyseal side of the plate but, before reaching the far cortex it breaks out and tracks down into metaphysis. most common. good prognosis. one of the greatest risk in a grade 2 fracture is causing growth rest by damaging the growth plate while reducing the fracture especially if this is attempted after a few days when the fracture may already be uniting .
Grade 3 Fracture line does not run along the epiphyseal plate at all . it crosses from the metaphysis to epiphysis. bony union may occur across the epiphyseal plate and block further growth causing most disfiguring progressing deformity of the limb if it is not promptly released. the key to management of this type of fracture is anatomical reduction if it is displaced, fracture is rare.
Grade 4 Fracture line travels along the distal side of the growth plate. it affects both the blood supply and the anatomical integrity of the germinal cells . the fracture line does not travel the whole length of the epiphyseal plate but deviates off into the epiphysis itself and out on the articular surface Poor prognosis. The key to successful of this type of fracture is anatomical reduction. performed by open surgery
Grade 5 This is rare and difficult fracture to diagnose. The injury is severe crush of the epiphyseal plate. The x-ray may only look abnormal in retrospect, and this is indeed how this type of fracture is usually diagnosed. The result of complete disruption of the growth plate is complete growth arrest .
Open fractures At the time of the fracture soft tissues over the bone will also b damaged. If the skin is broken there is a high probability that at some time during the accident the fracturing bone came in to contact with the outside world and contaminated with bacteria.
D. By management 1) Stable fractures :- are those which are unlikely to move further . 2) unstable fracture:- are those which will continue todisplace if the action is not taken to hold the fracture secure. there is gradation of stability which depends upon the following factors – SITE :- Fractures in weight bearing bones are more likely to be displaced by normal loads than those in bone which can easily be protected from load such as the long bones of the arm.
SHAPE ;- Spiral fractures tend to be unstable, while impacted fractures tend to be very stable. The more displaced the fracture, the more unstable it is likely to be. DISPLACEMENT :- Undisplaced fractures may have the periosteum intact and are therefore stable. The more displaced the fracture, the more unstable it is likely to be. BEHAVIOUR OF THE PATIENT :- patient who are prepared to be carefull can maintain the position of a fracture which would become displaced in a young hard- drinking male, who is not prepared to take any advice.
E. international classification In this classification simple alpha numeric code are given in which first no. relates to the bone second no. relates to the position of fracture on the bone. position no is followed by a letter which defines the severity of fracture This letter is followed by a further no. which classifies the fracture still further
Second no.(positon of fracture)1 = Proximal2 = Mid-shaft3 = Distal4 = Malleolar (ankle only)
Third alphabet(Severity offracture A = extra articular B = partial articular C = comminuted or complex Eg. – 42C????????????????????? Complex fracture mid-shaft of tibia
GENERAL MANAGEMENT. ABCDMaintain airway Breathing Circulation DisabilitySPECIFIC MANAGEMENT ReductionHolding a fractureRehabilitation
REDUCTION Reducing a fracture means trying to return the bones to as near to their original position as possible Types :- open Closed .Open :- In this case fracture is exposed surgically so that the fragmentscan b reduced under direct visionClosed :- If a fracture is reduced closed, then the accuracyOf the reduction can only be checked on an X-ray Advantage - The soft tissue and blood supply should not bedisrupted any further than occur at the time of trauma
Principles of closed reduction :- Relies on the attachments of the bone to soft tissues ( i.e. periosteum and/or ligament) to obtain and to hold reduction. PAIN RELIEF :- patient need to be free of pain when reducing fractures , so a general anaesthetic will be required if a regional block is not possible . VALUE OF PERIOSTEUM:-when the bone fracture periosteum remains largely intact, especially on the concave side of fracture. This strong membrane is not visible on X-ray. So its value may not always be fully appreciated .
Cont…… Impacted fractures which are also partially displaced will need disimpacting before the displacement can be corrected .Disimpaction is carried out by steady distraction to fracture until you feel the bone ends separate . force applied should not be more than 4 or 5 kg as otherwise there is danger of degloving the limb( pulling of the skin and soft tissue)Traction should be continued for couple of minutes to drive out edema outof the tissue around the fracture. This will allow the soft tissues to extend to their normal length and make the reduction easier.
ENGAGING THE BONE ENDS:-This is done by angulating the fracture even further than before and sliding the fractured end of the distal fragment up the cortex of the proximal fragment until it slips over the broken edge of the proximal fragment. when the fracture come to anatomical alignment, the intactperiosteum on what was the concave side will become tight and prevent over correction of the fracture.
2) OPEN REDUCTION OF FRACTURE:-exposure of s fracture should allow a adequate access to see asmuch of the fracture as necessary while minimizing damage to the soft tissue. It should also minimize the damage to the periosteum, which will be providing the bulk of blood supply to the broken bone fragments if that blood supply is lost the fracture cannot be unite. if there is skin & soft tissue loss then incision should be planned with a plastic surgeon to ensure that skin and soft tissue cover of the bone and fixation can be obtained at the end of operation.
Holding of fracture :-once the fracture has been reduced it need to be held until it has united ( the bone ends have joined together)PRINCIPLES OF HOLDING FRACTURE:- Two main ways – rigid fixation non- rigid fixation
RIGID FIXATION:- block the normal callus formation of the bone healing. in this fixation thee is no movement at fracture site. remodeling of the bone takes about a year in rigid fixation NON- RIGID FIXATION:- such as P.O.P(plaster of paris)It allows limited movement and the loading of the fracture site the aim is to allow movement and load to stimulate callus formation without allowing the fracture to redisplaced .
REHABIILITATION :-once fracture is stabilized , patient may needs helpwith rehabilitation so that they return to as fulland as independent a life as possible.
FIXATIONThe basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of the injured bone. 2 types – External fixation Internal fixation External fixation :- Those where the mechanical strength of the construct is outside the skin are defined as external fixation.
Internal fixation :-Implants which are fitted directly on to or put down the inside of the bone and are then covered with soft tissues and skin are classified as internal fixation. Types :- Screws Plates Wires Nails
PATHOPHYSIOLOGY OF FRACTURE HEALING BONE BREAKS Disruption of periosteum, trabaculae bone , blood vessels which run in the periosteum and medulla Haemorrhage and immediate release of cytokines Signals to cell locally that damage has occurred
Cytokines attract macrophages Cleaning up process startCytokines than attract undifferentiated stem cells which migrate in from endosteum & periosteum. Stem cells start differentating into fibroblast & bone forming cells Haematoma arround the fracture invaded in small capillaries Microphages remove the haemotoma itself
C.T tissue is laid down & slowly organisesOraganised C.T appear first as a collar arising from the periosteum close to the end of each broken bone Collars grow towards the collar on the other bone Eventually , spurs of callus meat and bridge the fracture site They become increasingly thick & strong fibrocartilage stabilises the fracture Now it is no longer possible to translate the fracture
In the fracture cleft itself , osteoclast continue to resorb haematoma Osteoclast then eat away other dead tissue & broken bone ends Now callus of fibrous cartilage arround the fracture cleft becomes calcified & then ossified (so that it visible on X-ray)Ossification starts at the bone end but in the centre of the fracture cleft,whereO2 levels may be very low , cartilage may be laid down intially rather than bone This cartilage is then replaced by bone (endochonral ossification)
Clinical union:- when the fracture can no longer beangulated with normal loads , and it is not painful to try , fracture is said to be clinically united. Radiological union:- On X-ray, when the strands ofossified callus can be seen to be stretching continuously from one bone end to another, fracture is said to be radiologically united Consolidation :- Finally , the callus forms a fat cuff of a woven bone from one bone end to the other this callus is as strong as the bone around it .because biomechanically it haswidened the diameter of the tube and this confers extra strength .This is called as consolidation.
Over the next months thewoven bone is replaced by haversian cortical bone which remodels over the following years .