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
Name 4 conditions in which spinal decompression surgery is an option
Spinal stenosis
Damaged IV disc
Fractured vertebrae
Tumour
What is spinal fusion
Where 2 or more vertebrae are joined together with a section of bone to stabilise and strengthen the vertebral column
Give some examples of soft tissue orthopaedics
- Tendon repair
- Tendon transfer
- Tendon lengthening
- Ligament repair
- Ligament replacement
- Free muscle transfer
In upper limb tendon transfer, what are the requirements of the donor muscle
Concious voluntary control
Expendable
Adequate tendon length
Innervated
What muscles can be used to complete following movements in radial nerve palsy
a) wrist extension
b) finger MCP extension
c) thumb extension
a) pronator teres to extensor carpi radialis brevus
b) flexor carpi ulnarus to extensor digitorum communis
c) palmaris longus to extensor pollicis longus
What innervates the pronator teres
Median nerve
What tendon most commonly requires lengthening
Achilles
How is the achilles tendon lengthened
V shaped incision used to lengthen it
Foot pushed into dorsiflexion
What % of knee ligament injuries are to ACL
40
What must a muscle be to be used as a transfer
Expendable
Relatively superficial
What is the definition of delayed healing
Failure to consolidate within 1.5 times the normal expected time
What is mal-union
Misalignment of proximal and distal fragments leading to biochemical deformity
What is non-union
Failure to consolidate within 2 hours the normal time
How does distraction osteogenesis work
Break the bone and keep the fracture open with external fixator to gradually lengthen it
What are 2 bone substitutes that can be used for a bone graft
Xenographs
Alloplast
What is osteoconduction
Physical effect by which the matrix of the graft forms a scaffold that favours outside cells to penetrate the graft and form new bone
What is osteoinduction
Chemical process by which molecules contained in the graft convert neighbouring cells into osteoblast
What is osteopromotion
Grafted material enhances osteoinduction
