Surgery Flashcards
Arthroplasty
Reshaping/replacement of the joint
Hemiarthroplasty
Replacement of only one side of the joint
What are the five common materials for joint replacements.
Stainless Steel Cobalt chrome Titanium alloy Polyethylene Ceramic
What is the issue with metal components?
They can trigger an inflammatory response resulting in a inflammatory granuloma (pseudo tumour)
What are the issues with a pseudotumour
It can trigger bone and muscle necrosis
What is the issue with polyethylene?
Can trigger an inflammatory response in bone resulting in osteolysis.
What is the issue with ceramics?
They can shatter
If infection of replacement caught within 3 weeks what is the treatment?
Surgical washout
Debridement
Parenteral antibiotics 6 weeks
50% success
If infection of replacement presents after 3 weeks what is the treatment?
Removal of infected implant and all foreign material.
Parenteral antibiotics until infection is under control.
Revision is performed.
Why does post three weeks require a more severe treatment?
As by this point a biofilm will have formed which prevent the immune system from attacking.
Early local surgical complications
Infection Dislocation Instability Fracture Nerve Injury Bleeding DVT
Early General Complications
Hypovolaemia Shock Acute Renal Failure MI PE 0.2% fatality in hip or knee replacement
Late Local complications
Infection - haematogenous spread easy to colonies metal objects Loosening Fracture Breakage Pseudotumour formation
Arthrodesis
Surgical stiffening or fusion of a joint in a functional position.
Usually for endstage pain relief
Osteotomy
Surgical realignment of a bone often by the removal of wedges.
Used to redistribute the load
Osteomyelitis
Infection of the bone
Causes of osteomyelitis
Penetrating trauma or surgery (inoculation)
Haematogenous spread
Why are young children more susceptible to osteomyelitis from haematogenous spread?
Young children have long tortuous vessels in their metaphysis with sluggish flow allowing bacteria to colonise.
When are antibiotics no longer effective in osteomyelitis ?
When a sequestrum forms and breaks off.
What is a sequestrum?
A dead fragment of bone.
What is a involucrum?
New bone forming around the area of infection in order to try and contain the spread and necrosis.
What is a Brodies abscess
A thin wall of sclerotic bone forms around the abscess.
Who present with Brodies abscess?
Children with subacute osteomyelitis.
Why in children do the abscesses often spread along the bone?
The have a loosely applied periosteum so it forms between it and the bone.
Acute osteomyelitis
In absence of surgery - Young children or immunocompromised adults
Chronic osteomyelitis
Develops from untreated acute
Associated with sequestrum and or involucrum
Where does chronic osteomyelitis usually present?
Axial skeleton
Usually haematogenous spread for UTI.
Peripheral
From open fracture or internal fixation.
Skeletal tuberculosis
Spread from primary lung infection.
What is a gibbus deformity?
Sharp angular change in the back as a result of destructive TB granuloma.
In kids what receptors should be checked?
IFN-gamma
IL-12
Osteomyelitis infective organisms.
Newborns under 4 months
S.aureus
Enterobacter sp.
Group A and B Strep
Osteomyelitis infective organisms.
4 months to 4 years
S.aureus
Group A strep
H.influenzaa
Enterobacter
Osteomyelitis infective organisms.
4 years to Adult
S.aureus 80%
Group A strep
H.influenzae
Enterobacter sp
Osteomyelitis infective organisms.
Adult
S.aureus
Occasionally enterobacter or streptococcus sp
Osteomyelitis infective organism
Sickle cell anaemia patients
S.aureus
Salmonella is unique
What is correct procedure regarding antibiotics in osteomyelitis.
Avoid empiric, chronic won’t kill you wait for lab results then use targeted antibiotics.
When are antibiotics used before lab results in osteomyelitis.
Septic arthritis
Soft tissue syndrome
What is surgical treatment for osteomyelitis.
Debridement and removal or all infected or unviable tissue.
Which groups are at risk of osteomyelitis of the spine?
Poorly controlled diabetics
Intravenous drug users
Immunocompromised
Where is most common location for osteomyelitis within the spine?
Lumbar region
How does osteomyelitis of the spine present?
Insidious onset back pain, unremitting and constant.
Paraspinal muscle spasm.
Fever and or systemic upset.
Severe may have neurological deficit.
