19 - Orthopaedics

Question 1

Indications for Joint Replacement

Answer 1

Degenerative disease
Inflammatory Disease
Trauma
Tumour
Vascular Disease
Revisions

Question 2

Most common joint replacement

Answer 2

Hip replacement

Question 3

What is the acrylic polymer used in cemented fixation

Answer 3

Polymethyl methacrylate

PMMA

Question 4

What is cementing

Answer 4

Using the PMMA as a filler between bone and the implant

Question 5

Cemented or cementless in an obese, osteoporotic, elderly person

Answer 5

Cemented

Question 6

Why does cementless take weeks for patient to move?

Answer 6

You need the bone cell to grow into the porous surface

Question 7

How big should the gap be in cementless

Answer 7

<0.5mm

therefore requires v precise placement

Question 8

What is a hybrid in cementing

Answer 8

Cemented stem

Cementless cup

Question 9

What is a reverse hybrid in cementing

Answer 9

Cementless stem

Cemented cup

Question 10

What is aseptic loosening

Answer 10

Resorption at the bone-cement interface causing it to be loose + wobble

Question 11

Which material has the least wear rate

Answer 11

Ceramic on ceramic (less than 1um a year)
(then metal on metal
then ceramic + CL polyethylene then oxinum+CL polyethylene )

Question 12

Which material has the highest wear rate

Answer 12

Metal in cross-linked polyethylene (200um a year)

Question 13

Why would you perform a spinal decompression surgery

Answer 13

Spinal stenosis
Damaged IV disk
Fractured vertebrae
Tumours

Question 14

What is a spinal fusion

Answer 14

2+ vertebrae joined together with a section of bone to stabilise and strengthen the vertebral column

Question 15

When would you do a tendon transfer

Answer 15

if your nerve is also damaged

Question 16

Mid shaft of humerus fracture

Answer 16

Wrist drop

radial nerve palsy

Question 17

What can you use pronator teres as

Answer 17

extensor carpi radialis brevis

Question 18

What can you use flexor carpi ulnaris as

Answer 18

extensor digitorum communis

Question 19

Most common ligament repair

Answer 19

ACL reconstruction

Question 20

Delayed fracture healing

Answer 20

Failure to consolidate within 1.5x the normal expected time

Question 21

Mal-union

Answer 21

Misalignment of proximal and distal fragments leading to biomechanical deformity

Question 22

Non-union

Answer 22

Non-union - Failure to consolidate within 2x the normal expected time

Question 23

Osteotomy

Answer 23

Realignment

Question 24

Distraction osteogenesis

Answer 24

Bone lengthening procedure

Progressive construction with use of an external fixator

Question 25

Osteogenesis

Answer 25

Development of new bone cells contained in graft

Question 26

Osteoconduction

Answer 26

Physical effect by which the matrix of the graft forms a scaffold that favours outside cells to penetrate the graft and form new bone

Question 27

Osteoinduction

Answer 27

Chemical process by which molecules contained in the graft convert the neighbouring cells into osteoblast

Question 28

Osteopromotion

Answer 28

When the grafted material enhances osteoinduction

Question 29

Bone substitutes

Answer 29

Xenografts

alloplasts

Question 30

Human bone grafts

Answer 30

Autografts

Allografts