ORTHO Flashcards
Fasciotomy for Compartment syndome
- Indications
- Technique
Fasciotomy
Indications
•immediate
-if evidence of vascular compression
•as soon as possible
- significant neurological dysfunction
- compartment pressures > 30 mmHg
- rhabdomyolysis
- myoglobin release continues until the ischaemia is relieved
Technique
- generous incision of the affected compartment
- wounds left open and covered with sterile dressings
- closed after swelling has subsided
-usually approximately 5 days
•prevents most myoneural defects when performed < 12 hours of symptom onset
Compartment Syndrome -
Assessmnet and How to check pressures
History
- onset usually between 6-24 hours following injury
- pain
- important early feature
- worse than expected from injury
- initially throbbing
- then becomes constant
•paraesthesia / numbness later
Examination
•skin perfusion over affected compartment is nearly always normal
Early
- pain on passive movement of muscles passing through the affected compartment
- tenderness over affected compartment
- venous congestion
Late
- neurological dysfunction
- decreased distal pulses
- decreased capillary return
- features of rhabdomyolysis
Investigation
Compartment pressure monitoring
•indicated if evidence of increased compartment pressure without clear indications for fasciotomy
Stryker pressure monitor
- local anaesthetic infiltration of the skin and subcutaneous tissue only
- 18G spinal needle or IV catheter is inserted into the compartment
-pushing on the muscles that run through the compartment should cause an increase in pressure measured
- pressure monitor is attached to the needle via saline filled IV tubing
- 1 mL of saline is injected into the compartment
- the compartmental pressure is then read
Compartment pressures
- normal - 0-8 mmHg
- 20 - 30 mmHg - compromise of capillary blood flow
- > 35 mmHg absent capillary blood flow
Pulse oximetry
•insufficiently sensitive to be of use
Dermatomes
Myotomes
Ottawa Ankle Rules
- exclusion
- the criteria
- sensitivity and specificity
Ottawa ankle rules
- used to determine need for X-rays in blunt trauma
- original study applied to adults only
•exclusion criteria
- altered mental state
- altered sensation in affected area
- patient has returned for reassessment of the same ankle injury
- injuries occurring more than ten days earlier
- when unable to accurately determine the presence of localised bone tenderness (e.g. altered mental state, dementia)
- patients who are not normally ambulatory
Ottawa criteria for ordering X-ray
- obvious deformed fractures or dislocations
- pain near the malleoli and any of the following findings
- inability to bear weight both immediately and for four steps in the ED
- bone tenderness at posterior edge (distal 6 cm) or inferior tip of the lateral malleolus
- bone tenderness at posterior edge or inferior tip of the medial malleolus
Accuracy and utility
•for the detection of clinically relevant ankle fractures
- 98- 100% sensitive
- 30-40% specific
- similar test characteristics in children 1-15 years of age
•may be less accurate in younger children and patients with diabetes
Salter Harris, Epiphyseal Injuries
Epiphyseal injuries
- 15% of long bone injuries in children involve the epiphyseal plate
- the epiphyseal plate is not as strong as bone, ligaments or tendon
- most commonly occur in children 10-15 years of age
Salter-Harris classification
Type I
- approximately 5% of epiphyseal injuries
- fracture through epiphysis only
- reduction usually not difficult
- prognosis excellent
- some apply a full cast to all ankle injuries with negative initial radiographs due to concerns about missing this type of injury
- however
- only about 3% of these patients have a type 1 injury and 85% have a ligamentous injury
- a removable splint appears to provide the same functional outcome as casting
- type 1 injuries appear to have a similar outcome to an ankle ligamentous injury
Type II
- approximately 75% of epiphyseal injuries
- fracture through part of epiphysis then up through the metaphysis
- reduction not difficult
- prognosis excellent
Type III
- intra articular fracture into epiphysis
- usually occurs in the tibia
- approximately 10% of epiphyseal injuries
- accurate reduction necessary but prognosis good
Type IV
- intra articular fracture that extends across epiphysis into metaphysis
- approximately 10% of epiphyseal injuries
- accurate reduction necessary
- reasonable prognosis
Type V
- crush injury to epiphysis
- X-ray findings may only be subtle
- approximately 1% of epiphyseal injuries
- prognosis poor
Mnemonic
- SALTR
- I - Slip of the physis
- II - Above the physis
- III - beLow the physis
- IV - Through the physis
- V - eveRything (or Rammed)
Contribution to growth
•the greater the contribution, the more important it is to ensure reduction
Humerus
- proximal 80%
- distal 20%
Radius, ulna and femur
- proximal 30%
- distal 70%
Tibia and fibula
- proximal 55%
- distal 45%
Management
Principles of reduction
•gentle technique
-forceful manipulation may further damage the growth plate
- early reduction has much better prognosis than delayed reduction
- younger children may have greater growth disturbance
- internal fixation across epiphysis substantially increases the risk of premature cessation of growth
Analgesia
•dependent on level of pain
-ranges from oral analgesics to parenteral opiates
•intravenous preferable for most acute fractures
Classification of ligamentous injuries
Classification of ligamentous injuries
Grade 1
- stretching of ligament only
- no disruption of fibres
- locally tender, minimal oedema
- no laxity on stressing
- treatment always conservative
Grade 2
- injury to portion of ligament
- moderate local tenderness and oedema
- mild instability, but firm end-point when stressed
- treatment usually conservative
Grade 3
- complete disruption of ligament
- discomfort with movement
-may be mild compared to degree of oedema
- oedema variable
- clear instability on stressing
- treatment usually operative
Perthe’s disease
Perthe’s disease
•segmental avascular necrosis of the femoral head
Epidemiology
- affects 1:1,200 children < 15 years old
- age range 5 - 10, median 7
- male : female 5:1
- 15-20% are bilateral
Assessment
•history
- well child often with intermittent limp
- may complain of hip, groin or knee pain
•examination
- reduced range of movement
- internal rotation and extension more painful
- unequal leg lengths
- investigation
- early radiological findings may be subtle
- initial increase in density of the femoral head
- followed by fragmentation, loss of contour
- epiphysial osteoporosis
- loss of joint space
SUFE
Slipped femoral epiphysis
(Dis-H)
Epidemiology
- commonly in adolescents, 10 - 15 year olds
- males 5x more common than females
- 60% of patients are obese
- early onset disease associated with hypothyroidism
Assessment
•history
- symptoms usually present for 6 months prior to diagnosis being made
- 25% occur after minor trauma
- pain often referred to thigh or knee
•examination
-externally rotated foot
•plain radiology
- lateral films diagnostic
- AP may look normal
- frog leg lateral view should also be obtained
- posterior slipping of the epiphysis on the metaphysis
- line along superior aspect of the femoral neck to the superior aspect of the acetabulum normally passes through the femoral epiphysis - Kleins line
- passes above in slipped epiphysis
- widened epiphysis
- ultrasound / CT / MRI may also be used to make the diagnosis
Metastatic Bony Tumours
Metastatic tumours
- more common than primary tumours
- mostly osteolytic
- may present with pathological fractures or bone pain
- pain absent in 70% of metastases
- bone pain most common cause of metastatic pain
Common primary sources
Adults
- lung
- kidney
- breast
- prostate
- thyroid
- colon
- adrenal
- myeloma
- neuroblastoma
- Ewing’s sarcoma
Children
- less likely than adults to have bone involvement
- neuroblastoma
- leukaemia
Common bone involved
- spine
- ribs
- pelvis
- skull
- proximal femur and humerus
-red-marrow content at these sites
•rare below the knee or elbow
Differential diagnosis
Osteolytic lesions
•metastases
- renal cell
- small cell lung
- thyroid
- melanoma
- lymphoma
- osteoarthritis (subchondral cysts, Schmorl nodes)
- metabolic bone disease
- cystic angiomatosis
- infiltrative bone-marrow lesions
Osteosclerotic lesions
•metastatses
- prostate
- carcinoid
- small cell lung
- Hodgkin’s lymphoma
- medulloblastoma
- bone islands
- tuberous sclerosis
- mastocytosis
- osteopoikilosis
Primary Bone Tumours
Malignant primary tumours
Types
•aneurysmal bone cyst
- 10-30 years old
- eccentric in long bone
- osteosarcoma
- chondrosarcoma
- giant cell sarcoma
- Ewing’s tumour
- Paget’s sarcoma
- irradiation sarcoma
Imaging
Plain X-rays
•usually only detect lesions > 2 cm in size
-usually > 50% of the bony cortex is destroyed by this time
CT scanning
- more sensitive than plain radiography
- can improve characterisation of the lesions
- may also be used to biopsy lesions
Bone scanning
•similar sensitivity to CT scanning
MRI
- useful for the assessment of equivocal lesions detected by other imaging studies
- may be more sensitive than bone scanning for detect metastases
Radiological features of malignancy
•definitive diagnosis commonly not possible with radiology alone
Features
- soft tissues well defined if early
- poorly defined margin
-although osteomyelitis also has this feature
- absence of surrounding sclerosis
- break in the cortex
- periosteal reaction
- not a particularly good sign
- thin, lamellated (onion-skinned) and amorphous
Benign tumours
Fibroxanthoma / fibrous cortical defect
- asymptomatic, usually incidental finding
- 30% prevalance in children
- most commonly located around the knee and distal tibia
- lesions comprised of fibroblasts
Fibrous cortical defect
- peak prevalence in 10-15 year olds
- rare in patients > 30 years of age
- usually smaller than 2 cm
- located in cortex of metaphysis
- eccentric
- appears like a bubble
- thin, sclerotic border
- becomes sclerotic as healing occurs
Fibroxanthomas
- peak prevalence in adolescents and young adults
- rare in patients > 40 years of age
- > 3 cm in size
- eccentric, intramedullary adjacent to the cortex
- scalloping pattern in the adjacent cortex
Simple bone cyst
- usually in patients < 30 years of age
- common cause of pathological fracture in childhood
- asymptomatic, unless it causes a pathological fracture
- most commonly affects long bones, especially
- proximal humerus
- proximal tibia
- femur
Appearance
- arises within the physeal growth plate then extends into diaphysis
- solitary
- centrally located
Joint Fluid Aspirate
Synovial fluid
Normal
- clear / straw coloured
- quite viscous due to the presence of hyaluronidase
- WCC < 200/µL
Inflammatory
- turbid
- less viscous
- WCC 2,000 - 50,000/µL
- usually > 50% polymorphs
Infected
- opaque
- easily withdrawn
- WCC of > 50,000/µL
- > 85% polymorphs
- early or partially treated infections may have an intermediate WCC
- bacteria may be seen on and Gram stained fluid under microscopy
- surface antigens of H.influenzae and S.pneumoniae may also be detected
- bacteria grows on culture
Phase contrast microscopy
•must be performed at time of aspiration as crystals may dissolve if left in synovial fluid
- store fluid at -20o C to -70o C if delay of many hours likely prior to analysis
- cell and crystal morphology is preserved for many weeks at this temperature
•presence of intracellular crystals strongly suggests crystal induced arthropathy
-rarely, other causes of acute arthritis may precipitate an attack of acute gout at the same time
Urate crystals
- needle shaped
- strong negative birefringence
Calcium pyrophosphate crystals
- rod shaped or rhomboid
- weak positive birefringence
Knee Dislocation
Knee dislocation
- knee is a very stable joint
- uncommon, but severe injury
- usually involves high energy injuries
-however low energy injuries are common in patients with obesity
- may be anterior, posterior, medial, lateral or rotatory
- 20-30% are open injuries!
- commonly multiple ligamentous injuries
- single cruciate in 85%
- both cruciates in 70%
- medial or lateral collateral ligaments in 40-60%
- intra-articular fractures present in 25%
- joint usually hinges around one collateral ligament
- popliteal artery (and vein) injury in 35-40%
- presence of distal pulses does not exclude arterial injury
- low threshold for angiography
- high risk of compartment syndrome distally
- peroneal nerve injury in 25-35%
- 80% risk of amputation if reduction delayed > 8 hours
Reduction
•spontaneous in 65% prior to hospital
-risk of vascular injury still requires evaluation
•if still dislocated, reduction usually easy with appropriate sedation / anaesthesia
-reduced with longitudinal traction
•compartment syndrome may be delayed after reduction
Indications for CTA/angiography
- confirmed dislocation
- suspected spontaneously reduced dislocation
- multiple ligamentous injuries/laxity
- potentially unstable bony injuries to the knee
- large knee effusion
- reduced distal pulses
- abnormal ankle/brachial index
Management
- systemic anticoagulation with unfractionated heparin
- 40% of patients with an abnormal vascular examination will have major vascular injury requiring a reverse saphenous vein bypass graft
Ottawa Foot Rules
Ottawa foot rules
- used to determine need for foot X-rays in blunt trauma
- usually used in conjunction with ankle rules
- applies only to mid-foot fractures
- X-ray all patient with obvious deformed fractures or dislocations
Ottawa criteria for ordering mid foot X-rays
•X-ray if pain in the mid-foot and one or more of the following findings
- inability to bear weight both immediately and in the ED (four steps)
- bone tenderness at the base of the 5th metatarsal
- bone tenderness on the navicular
Accuracy and utility
•100% sensitive, 79% specific for detecting clinically significant mid-foot fractures
Back Pain Red Flags
•age
- increased risk for fracture (LR+2) over 65 years
- age > 70 years (LR+ for fracture 11, even higher for females)
•trauma
- usually significant
- recent mild trauma in those over 50 years of age
- especially when visible contusions are present (LR+ 30)
•prolonged steroid use
-LR + for fracture of > 10
•history of osteoporosis
•prior history of cancer (LR+ about 20)
•history of a recent infection
•fever
•IV drug use
•low back pain worse at rest
•unexplained weight loss (poorly predictive of malignancy, if at all)
