Transcript Case 2 - Ipswich-Year2-Med-PBL-Gp-2

Milad is a 23 year male Afghan refugee who arrived 2 weeks ago via
boat from Indonesia. He presents to the detention centre medical
facility with left arm pain. Through an interpreter he tells you that
the pain may have begun around 4 weeks ago, although he is not
certain - he indicates the pain is mainly around the upper aspect of
the lateral humerus. There was a minor injury on the boat when
he fell onto the shoulder about 1 week prior to arrival which
aggravated the pain and it has failed to improve since. He has felt
slightly nauseated, but hasn't vomited and was sweating last
night.
Issues for consideration:
1. What anatomical structures can give rise to pain in the upper
arm?
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Bone
Muscle
Tendons/ligaments
Nerves- referred pain from heart and
shoulder
Murtugh
Pain present in the distribution of the C5 nerve
can arise from the:
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cervical spine
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upper roots of brachial plexus
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glenohumeral joint
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rotator cuff tendons, especially
supraspinatus
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biceps tendon
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soft tissue viscera, especially those
innervated by thephrenic nerve (C3, C4,
C5).
2.
What are most likely to cause ongoing
pain?
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Systemic issue: Malignancy, infection
ACS
Associated or separate PC
YES
 Risk factors for tuberculosis, HIV and other
infections
 Poor hygiene/overcrowding in refugee camps
 disease, infection
 Previous trauma/abuse
 Malnutrition
 Lack of previous health care
 Psychosocial issues
Examination reveals that he has a fever of 38.6o, pulse 104
per minute and BP 110/65. There is no swelling or
deformity of the arm. There is an area of erthyema over
the lateral arm, below the insertion of the deltoid
muscle. There is tenderness around the same area.
There is some wasting of the deltoid and supraspinatus
muscles on the left when compared to the right. Distal
neurovascular, tendon function and pulses are normal.
Issues for consideration:
1. What would be the likely diagnoses following the
examination.
?Osteomyelitis
Acute osteomyelitis typically presents with gradual onset of
symptoms over several days. Patients usually present with dull
pain at the involved site, with or without movement. Local
findings (tenderness, warmth, erythema and swelling) and
systemic symptoms (fever, rigors) may also be present.
However, patients with osteomyelitis involving sites such as
the hip, vertebrae, or pelvis tend to manifest few signs or
symptoms other than pain. Subacute osteomyelitis generally
presents with mild pain over several weeks, with minimal
fever and few constitutional symptoms.
- But “In long bone hematogenous osteomyelitis, the most
common site of infection is in the metaphysis.”
?Cellulitis- but no swelling and very specific description of
erythema location….
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Investigations
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Imaging
 X-ray, CT, MRI, nuclear study (if can’t use others)
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FBC
 Nonspecific: increased CRP/ESR, WCC
 Culture. If find something which could
osteomyelitis, biopsy
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Bone Biopsy
 Histopathology
 Culture
cause
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Tx.
Debridement – removal of necrotic tissue, revas…
 Antibiotics. Tailor to organism, otherwise treat
empirically with vroad spectrum.
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Prolonged duration required.
Things to consider: bone penetration, vascular supply
Gram neg = fluoroquinolones (high bone penetration)
Beware MRSA
Rifampicin vs biofilm bacteria
Adjunctive therapy
 Hyperbaric oxygen (rectify low oxygen tension, helping
neutrophils and macrophages) and negative pressure wound
therapy (NPWT)/vacuum-assisted closure
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You refer Milad for an x-ray and blood tests;
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Hb 115
WCC 15.6
Neutrophil 9.4
Platelets 130
ESR 97
CRP 128
[130 – 170 g/L]
[4.0 - 10.0 x10^9/L]
[2.0 - 7.0 x10^9/L]
[150 – 400 x 10^9/L]
Cultures pending. (later show Staphlococcus
aureus)
X-ray = lytic lesion of upper humerous
Orthopaedic surgeon review organised. CT taken
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Almost always caused by bacteria (S. aureus )
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Haematogenous spread
 Mucosa damage : defecation, chewing hard foods,
minor skin infections
 DM foot infection
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Contiguous site extension
 Associated with vascular insufficiency (DM, peripheral
vascular disease)
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Direct implantation
 Complication of open fracture
 Surgical procedures
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What is the pathogenesis of Osteomyelitis?
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Multifactorial and poorly understood
 Virulence of infecting organism
 Underlying disease/ immune status of host
 The type, location and vascularity of the bone
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Virulence factors:
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Adherence (S. aureus = fibrinogen, collagen…)
Resistance to host immune system
Proteolytic activity
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Up-to-date says…
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Neonates:
 Small capillaries cross the epiphyseal growth plate, allowing inf. into
epiphysis and joint space.
 Thin loose woven cortical bone permits escape of pressure caused by
inf., but also allows rapid spread directly into subperiosteal region
which can  subperiosteal abscess.
 No large sequestrum as no extensive infarction of cortex occurs
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Children >1yo:
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Inf. starts in the metaphyseal sinusoidal veins
Contained by growth plate.
Joint spared unless metaphysis is intracapsular
Inf. spreads laterally, breaks through cortex, lifts loose periosteum 
subperiosteal abscess
Adults:
 Growth plate resorbed. Inf. may extend to joint spaces
 Periosteum is attached to underlying bone, therefore subperiosteal
abscesses and intense periosteal proliferation is rarely seen
 Can erode through periosteum  draining sinus tract
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Haematogenous
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Catheter/illicit drugs
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Aspergillus, mycobacterium avium,
candida albicans
Foreign body
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Fungemiacandida
Injection drug addicts: Pseudomonas
aeruginosa
Immunocompromised
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Neonates: Haemophilus influenzae,
S. aureus, group B streptococci
Children and Adults: S. aureus
(MRSA)
Elderly: Gram negative rods
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Mycobacterium tuberculosis
Endemic pathogens for specific
region
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Bartonella henselae
TB prevalent areas
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Salmonella, Strept pneumoniae
HIV
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Streptococci, anaerobes
Sickle cell
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Staphylococci (coagulase neg.),
proprionibacterium
Enterobacteria, pseudomonas
aeruginosa
E. coli, Klebseilla
DM foot ulcers, bites
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Nosocomial
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UTI
Brucella, coxiella burnetii (Q fever),
others
NO ORGANISM FOUND IN ~ 50%
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5-25%: acute fails to resolve  chronic infection
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Acute flare ups
Pathologic fracture
Contigous structure involvement (joints, soft tissue)
 sinus tract formation
Secondary amyloidosis
Endocarditis
Sepsis
SCC in sinus tract, Sarcoma in infected bone (rare)
Resolution (AB + surgical drainage)