Orthopaedics Flashcards
Name 4 potential stressors to the musculoskeletal system
- Trauma
- Infection
- Altered metabolism
- Neurological
6 indications for joint replacement in adults
1) Degenerative disease such as osteoathritis
2) Inflammatory disease
3) Trauma (fracture of femur neck)
4) Tumour
5) Vascular disease such as avascular necrosis
6) Revision of previously/ worn out joint replacement
What does THR stand for
total hip replacement
Which type of hip replacement is most expensive
Cementless
What is the lifespan of a hip replacement
15-20 years
3 ‘types’ of hip replacement
Cemented
Hybrid
Uncemented
What is the role of cement in a hip replacement
Encourage the bones to move into the surface so will last longer
Bone and the cement must lock together
Acts as a filter between the bone and the implant
What polymer is used in the cement in the hip replacement
Polymethyl methcrylate (PMMA)
Describe the surface of an uncemented hip replacement
Rough surface
Covered by porous or hydroxyapatite
With what pore size in maximum bone ingrowth obtained
100-200um
What should gaps be in uncemented hip replacement
<0,5mm
What kind of patients are cemented hip replacements more suitable for
Obese patients
Dysplastic hips
Patients with osteoporosis
What kind are patients are uncemented hip placements more appropriate for
Younger more active patients
What is the wear rate of ceramic on ceramic
Less than 1 um a year
What is the wear rate of metal in cross linked polyethylene
200um a year
