PBL 5 Flashcards
what is a delayed union
Delayed union = failure to consolidate within the normal timescale for that type of fracture and location
what is a non union
failure to consolidate within 2x the normal expected time
What are the causes of non union
- distraction at fracture site
- soft tissue loss
- bone loss
- soft tissue interposition
- poor blood supply
- haematoma
- infection
- poor splint age
- poor fixation
- age
- poor medical conditional
- NSAIDS
- fluoroquinolone
What is pseudoarthrosis
formation of a false joint where a fibrocartilaginous cavity is lined with synovial membrane
what cases do you supply stability for fracture healing
If biology good (i.e. there is a callus and a
blood supply then provide stability, correct
deformity a
If biology is poor then provide stability and
use a bone graft
If biology is bad then use a bone graft and
Other reconstruction and provide stability
Name the different types of factors affecting bone healing
Local risk factors: open fractures, high energy fractures, severe associated soft tissue injury,
bone loss and infection
Iatrogenic factors: poor reduction, unstable fixation, bone devitalisation
Systemic factors: malnutrition, smoking, NSAIDs, systemic medical conditions (e.g. diabetes)
chronic alcoholism
Patient factors: non-compliance
How do bone and joint infections work
- Local spread from adjacent tissues
haematogenous
- synovium = septic arthritis
- metaphysic = osteomyelitis
- direct inoculation or penetrating injury or surgery
Describe the pathophysiology of osteomyelitis
- pus may enter the joint
- pus forms in the metaphysic
- in some joint capsule attaches below the growth plate
- pus escapes under periosteum and into soft tissues
- there is a sequestrum which is dead bone in the middle and new bone forms around this, this happens as blood supply is blocked
How do you diagnose osteomyelitis
- serological studies
- CT
- indium labelled white blood cell scan
- bone culture
- CRP, ESR, WBC
- bone biopsy
- physical exam
what is indium labelled WBC
anuclear medicinetest which attempts to localise infection and/or inflammation by injecting the patient’s previously extracted and radioactively-labelledwhite blood cells.
How does indium labelled WBC work
- labelled with indium 111 Oxine and injected back into the patient
- patient needs to receive his or her own white blood cells back and careful systems must be put in place to ensure this occurs
- patient is imaged 24 hours later giving the white blood cells the opportunity to migrate to the site of inflammation and infection
- labelled leucocytes localise at the site of infection through diapedesis, chemotaxis and enhanced vascular permeability
why did she have broad spectrum IV antibiotics
The cultures came back with a mixture of bacterial species so broad spectrum IV antibiotic therapy continued for 6 weeks.
How do you treat osteomyelitis
describe the treatment of osteomyelitis
- early testament includes local antibiotics delivery straggles for bony defect and adequate soft tissue coverage
- 6 week course of IV antibiotic based on biopsy
- at 6-8 weeks proceeded to second stage reconstruction with cement spacer removal and autologous bone grafting
What are the types of bone graft
Autograft Allograft (mineralised) Allograft (demineralised) Xenograft Alloplast