Orthopaedics

Question 1

What are stressors of the musculoskeletal system

Answer 1

Trauma

• Sports injuries
• RTA’s
• Overuse

Infection
- Bone and joint

Altered metabolism

• Age related
• Disease related

Neurological

• Muscle spasticity
• Muscle paralysis

Question 2

what joints can be replaced

Answer 2

All joints

• Upper limb: shoulder / elbow / wrist / hand
• Lower limb: hip / knee / ankle
• Spine: disc replacements

Question 3

what are the indications for joint replacement

Answer 3

Degenerative disease (e.g. osteoarthritis)

Inflammatory disease (e.g. rheumatoid arthritis)

Trauma (e.g. fracture neck of femur / fracture neck of humerus)

Tumour

Vascular disease (e.g. Avascular necrosis)

Revision of previously failed / worn out joint replacement

Question 4

what are the three types of joint replacement

Answer 4

cemented

hybrid - cemented stem but acetabulum is uncemented

reverse hybrid - uncemented stem and cemented cup

uncemented

Question 5

uncemented is more…

Answer 5

expensive but is now more common

Question 6

how long do joints last

Answer 6

15-20 years

• depends on type of replacement
• type of materials used

Question 7

what is one of the most common surgical proceeder today

Answer 7

total hip replacement

Question 8

some joints will always require …

Answer 8

cemented

Question 9

name a difference between cemented and uncemented

Answer 9

• Cemented = can get the person mobile the next day
• uncemented.=. have to wait for the bone to grow into the porous part of the replacement joint therefore takes 4-6 weeks of non weight bearing on that joint

Question 10

who is cemented better for

Answer 10

• obese
• elderly
• people with osteoporosis

Question 11

what polymer is in cemented replacements

Answer 11

Cemented fixation uses an acrylic polymer
Poly(methyl methacrylate) (PMMA)
- can give prophylactic antibiotics to prevent infections

Question 12

described cemented placement

Answer 12

• both the bone and cement must lock together to make the insertion last
• cement simply acts as a filler between the bone and the implant

Question 13

describe the uncemented replacement

Answer 13

Uncemented have rough surface covered with porous or hydroxyapatite covering

Maximum bone ingrowth is obtained with pore size 100-200 μm

Gap should be <0.5mm to encourage bone growth

Question 14

describe the benefit of using ceramic on ceramic as a new biomaterial

Answer 14

• has least wear
• less than 1 um a year -
• fewer infections
• more inert and less likely to start an immune reaction therefore less chance of aseptic loosening
• but small rate of catastrophic failure - over stress ceramic can cause it to collapse

Question 15

describe other biomaterials that can be used

Answer 15

ceramic on ceramic

Metal on metal

Ceramic in cross-linked polyethylene

Oxinium in cross-linked polyethylene

Metal in cross-linked polyethylene

• 200μm a year
• can lead to aseptic loosening

(listed in the wear and tear rate)

Question 16

what joint has the least wear rate

Answer 16

ceramic on ceramic

Question 17

what is the indicators for spinal decompression surgery

Answer 17

Spinal stenosis

Damaged IV disc

Fractured vertebrae

Tumours

Question 18

what is spinal fusion and what is it for

Answer 18

Where 2 or more vertebrae are joined together with a section of bone to stabilise and strengthen the vertebral column
- won’t affect the movement of the vertebral column as the movement between two vertebra is quite small

Question 19

What can you use for spinal decompression surgery

Answer 19

bone graft

spinal fusion

IV disc replacement - allow rotational movement

inject bone cement in the centre of the vertebral body that will harden the vertebra

Question 20

what soft tissue treatments are there

Answer 20

Tendon repair

Tendon transfer

Tendon lengthening

Ligament repair

Ligament replacement

Free muscle transfer

Question 21

what are the options for tendon transfer for radial nerve palsy

Answer 21

• PT to ECRB for wrist extension
• FCU to EDC for finger MCP extension
• PL to rerouted EPL for thumb extension
  Or
• PT to ECRL and ECRB
• FDS III to EDC
• FDS IV to extensor indicis and EPL
• FCR to APL and EPB

Question 22

what is tendon lenghting for

Answer 22

• this is where you have hypertonia in muscle groups
  for example
• For the lower limb one of the antagonist groups of muscles that are stronger than the other for example the quads are stronger than the hamstring and plantarflexors are stronger than dorsiflexors
  Hypertonic plantarflexors – end up toe walking, dorsiflexors cannot counteract it

Question 23

what can you use for ACL reconstructions

Answer 23

patellar ligament tibia graft,

• goes down from the patellar down the patella ligament to the tibia tuberosity where it inserts, this is meant to heal in quicker as it is bone
• tends to heal quicker

Hamstring

• semitendinous overlies semimembranous therefore you can stitch the muscle to semimebranous underneath it and take the tendon part of semitendinous and use it for the ACL
• gracilis tendon

Question 24

What is the unhappy triad

Answer 24

Medical mescius
ACL
Medial collateral ligament

Question 25

what are free muscle transfer

Answer 25

can use gracilis muscle and rectus femurs

Question 26

what muscles are used in free muscle transfer

Answer 26

- gracilis or rectus femoris - or any muscle that is expendable (other muscles do its role) - under voluntary control - is superficial

Question 27

what can the gracilis muscle be used for

Answer 27

Deltoid reconstruction Elbow flexion Elbow extension Finger flexion Finger extension

Question 28

what is mal union

Answer 28

bone has healed but there is Misalignment of proximal and distal fragments leading to biomechanical deformity

Question 29

what can mal union lead to

Answer 29

Rotation Angulation Shortening Translation

Question 30

what is delayed

Answer 30

Failure to consolidate within 1.5x the normal expected time

Question 31

What is non union

Answer 31

Failure to consolidate within 2x the normal expected time

Question 32

what happens in non union

Answer 32

Can be Atrophic / Hypertrophic depending on: - blood supply - degree of stability

Question 33

what can be used to treat a mal union

Answer 33

Osteotomy | - Re-alignment osteotomy

Question 34

What can be used to treat a shortened bone

Answer 34

- Distraction osteogenesis | - progression correctvtion with use of an external fixator (e.g. Ilizarov technique)

Question 35

name 4 types of bone graft

Answer 35

Osteogensis osteoconduction osteoinduction osteopromotion

Question 36

what is osteogenesis

Answer 36

Formation or development of new bone cells contained in graft

Question 37

what is osteoconduction

Answer 37

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 38

what is osteoinduction

Answer 38

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

Question 39

what is osteopromotion

Answer 39

When the grafted material enhances osteoinduction

Question 40

define autograft

Answer 40

a tissue or organ that is grafted into a new position on the body of the individual from which it was removed.

Question 41

define allografts

Answer 41

a tissue or organ obtained from one member of a species and grafted to a genetically dissimilar member of the same species.

Question 42

define xenografts

Answer 42

a graft obtained from a member of one species and transplanted to a member of another species.

Question 43

define alloplast

Answer 43

an inert foreign body used for transplantation into tissues.

Question 44

what rehabilitation takes place after orthopaedic surgery

Answer 44

Orthopaedic Physiotherapy - specialises in treating patients undergoing planned surgery - or those who are admitted to hospital due to a traumatic accident or incident