General Orthopaedic Surgery Principles Flashcards
Define compartment syndrome
Critical pressure increases within a closed fascial compartment that compromises the neurovascular bundle
Presentation of compartment syndrome
- disproportionate pain which is not improved by analgesia
- pain is worsened by passively stretching the muscle bellies
passive stretch test - 5Ps
What are the 5 Ps of acute limb ischaemia which can be seen in compartment syndrome?
- pain
- pallor
- Perishingly cold
- paralysis
- Pulselessness
What is the most reliable diagnostic test for compartment syndrome?
What blood test can aid diagnosis?
Intra-compartmental pressure monitor
Elevated creatine kinase
What is the most sensitive sign of compartment syndrome?
Passive stretch pain
Management of compartment syndrome
-
urgent fasciotomy
Prior to surgery: - keep limb at neutral level
- O2 administration
- IV fluid bolus
- remove dressings/casts
- IV opioids
- monitor renal function + Rhabdomyolysis
Consequences of inadequate treatment of compartment syndrome
- ischaemia
- Rhabdomyolysis + AKI
- nerve death
- Volkmann’s ischaemic contracture
Explain how inadequate treatment of compartment syndrome can cause Volkmann’s ischaemic contracture
- compartment pressure increase > compartment syndrome
- due to lack of O2, muscles undergo infarction
- in repair, muscle tissues are replaced by scar tissue through fibrosis
- myofibroblasts in fibrosis contract
- flexion contracture
What is osteomyelitis?
Inflammation in a bone + bone marrow caused by bacterial infection
What are the three ways osteomyelitis can occur?
Which is most common?
- haematogenous osteomyelitis (most common)
- direct inoculation e.g. surgery or at open fracture site
- direct spread froom nearby infection
What is haematogenous osteomyelitis?
When a pathogen is carried though the blood and seeded in the bone
What is the most common microorganism that causes osteomyelitis?
Staph aureus
Risk factors for osteomyelitis
- open fractures
- orthopaedic operations
- diabetes
- peripheral arterial disease
- IV drug use
- immunosuppression
Presentation fo osteomyelitis
- fever
- pain + tenderness
- erythema
- swelling
- generalised infection symptoms
What is the what is the gold standard for osteomyelitis investigations
Culture from bone biopsy at debridement
MRI
X ray signs of osteomyelitis
- periosteal reaction | changes to the surface of the bone
- localised osteopenia
- destruction to areas of the bone
Investigations of osteomyelitis
- MRI
- blood tests - raised inflammatory markers
- blood cultures
Management of osteomyelitis
- surgical debridement
- antibitoics
Abx management of acute osteomyelitis
- 6 weeks of flucloxacillin
- possibly with rifampicin or fusidic acid added for first 2 weeks
. - clindamycin if penicillin allergy
- vancomycin if MRSA
What are sarcomas?
Cancers originating in the muscle, bones or other connective tissue
Types o bone sarcomas
- osteosarcoma (most common)
- chondrosarcoma: cancer of the cartilage
- ewing sarcoma: a form of bone + soft tissue cancer affecting children + young adults
Outline Kaposi’s sarcoma
- cancer that forms in the blood vessels + lymph vessels
- associated with infection of human herpesvirus 8
- causes red/purple lesion on the face, arms + legs
Presentation of sarcoma
- depends on location + size
- soft tissue lump | growing, painful, large
- bone swelling
- persistent bone pain worse at night
Investigations of suspected sarcomas
- X-ray for bony lumps or persistent pain
- USS for soft tissue lumps
- CT or MRI for more detail + to look for metastatic spread
- biopsy
What is the most common location for sarcoma to metastasise to?
Lungs
Management of sarcoma
- depends on type, location, size + stage
- surgical resection
- radiotherapy
- chemotherapy
- palliative care
What is the most common cause of bone cancer?
From what sites?
Metastatic spread from other cancers
Such as renal, thyroid, lung, prostate + breast
What are osteochondromas?
Benign bony tumours forming as an outgrowth from the metaphysics
Normally asymptomatic and slow growing
What are Ewing sarcomas?
Aform of bone + soft tissue cancer affecting children + young adults
Presentation of Ewing’s sarcoma
Painful + enlarging mass with tenderness + warmth
Management of Ewing’s sarcoma
Neoadjuvant chemo
Followed by surgical excision
Features of benign vs malignant X-rays
- benign: sharp, well defined, lacks soft tissue involvement, no cortical destruction
- malignant: poorly defined, rough boarders, involves soft tissues, cortical destruction
when should patients be assessed for osteoporosis?
women >65
men >75
earlier if risk factors present
Risk factors of osteoporosis
- previous fragility fracture
- falls history
- low BMI
- smoking
- excessive alcohol intake
.
Causes of secondary osteoporosis: - hypogonadism
- diabetes mellitus
- Cushing’s
- IBD (due to malabsoprtion)
- RA
Outline the methods of risk assessment for osteoporosis
- exclude a secondary cause
- recent fragility fracture - look for pathological causes
- fragility risk score FRAX or QFracture
- DEXA scan if >50 with hx of fragility fracture or <40 with major risk factors of fragility #
what can be used to assess fragility fracture score?
FRAX
QFracture
Outline FRAX
- fragility fracture score
- assess pt 10 year risk of fracture
- colour risk if given -green, orange or red
- orange or red > DEXA scan
Outline QFracture
- fragility fracture risk score
- pt 10 year risk of developing a fracture
- if >10% then DEXA scan
What does the T score in a DEXA scan mean?
T score describe bone density as a standard deviation in comparision to the bone mass of young reference population
e.g. -2.5 > 2.5SD below that of average healthy adult
What does the T score indicate?
above -1.0 : normal
-1.0 to -2.5 : osteopenia
-2.5 or lower : osteoporosis
What T score on a DEXA scan indicates osteopenia?
-1.0 to -2.5
What T score on a DEXA scan indicates osteoporosis?
-2.5 or lower
When should you start bone protection on patients who are going to take long term steroids?
immediately
Medical treatment for reducing risk of fragility fractures
- calcium + vitamin D
- bisphosphonates e.g. alendronic aicd
- denosumab
Define fracture
Break in the continuity of bone
Types of fractures
- transverse
- oblique
- spiral
- segmental
- comminuted
- compression fracture
- greenstick
- buckle/torus
- salter harris
Anatomical description of fracture
Type
Comminution
Location
Displacement
Define displacement
Types
- More than 1cm away from its normal alignment
- translation
- angulation
- shortening
What are pathological fractures?
occur due to underlying disease of bone:
- osteoporosis
- malignancy
- Paget’s disease of bone
what are the main cancers that spread to bone?
prostate
renal
thyroid
breast
lung
What can a fat embolism cause?
systemic inflammatory response > fat embolism syndrome
24-72 hours after fracture
Diagnosis of fat embolism
Gurd’s criteria
What is Gurd’s crieteria?
what is it used for?
diagnosis of fat embolism
.
Major criteria:
- respiratory distress
- petechial rash
- cerebral involvement
.
Minor criteria:
- jaundice
- thrombocytopenia
- fever
- tachycardia
- + more
Management of fat embolism
Supportive while condition improves
What is needed before surgery
- Xrays
- CT or MRI for more detail
- pre-op assessment
- consent for surgery
- bloods incl G+S and crossmatch
- ECG
- VTE assessment
- fasting
What is Paget’s disease of bone
- Condition where there is increased bone remodelling > excessive bone resportion + growth > skeletal deformities + fragile bones
- Most commonly affects skull, pelvis, spine + legs
Presentation of Paget’s disease of bone
- initially asymptomatic
- impingement of nerves > pain
- leontiasis: overgrowth of skull bones > lion face
- hearing loss
- vision loss
- kyphosis
Diagnosis + investigations of Paget’s disease of bone
- elevated levels of ALP
- X ray: lyric lesions
- bone biopsy to exclude malignancy
Treatment of Paget’s disease of bone
- analgesia
- bisphosphonates
- surgery to correct deformities
