Growth & Repair Flashcards

1
Q

Describe the parts of a long bone?

A

Diaphysis - Shaft
Metaphysis - Flare at the end of the shaft before epiphysis, contains growth plate
Epiphysis - Joint-end of the bone, after the epiphyseal plate
Medullary Cavity - Inside diaphysis, full of marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Whats the structural difference between cortical and cancellous bone?

A

Cortical is made of cylindrical osteons of concentric lamenae. They contain central canals of veins/arteries.

Spongy Bone contains marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the geographical difference between compact and spongy bone?

A

Cortical bone is found in the diaphysis of long bones

Trabecular is found in the metaphysis & growth plate of long bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the functional difference between cortical and cancellous bone?

A

Compact resists bending & torsion

Cancellous resists compression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the stages of fracture repair?

A

1) Inflammation
2) Soft Callus
3) Hard Callus
4) Bone Remodelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How might we intervene in stage 1 of fracture repair?

A

Inflammation

  • NSAIDS for inflammation (there is debate as to whether they help the pain more or delay healing more)
  • Plate Concentrates to improve healing e.g. Platelet derived growth factor (PDGF), IGF & VEGF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the soft callus stage of fracture repair?

A

The inflammation/swelling goes down
Cartilage and fibrous tissue start to unite the bony fragments.
It gives back some stability but angulation ca still occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What interventions are possible for stage 2 of fracture healing?

A
  • Cartilage replacement with DMB (Demineralised Bone Matrix)
  • Bone Graft
  • Bone substitutes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the types of bone graft?

A

Autogenous Cancellous Bone Graft (Gold standard). IS both osteoconductive and inductive.

Allograft - Osteoconductive but not inductive and risks transmission of disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens during the 3rd stage of fracture repair?

A

Cartilage forms into woven bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens during the 4th stage of fracture repair?

A

Woven bone forms into lamellar bone and the medullary canal is reconstituted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is strain involved in fracture repair?

A

Mechanical strain induces tissue differentiation so if strain is too low you don’t grow fresh bone
If its too much then the healing process is interrupted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the structure of a peripheral nerve?

A

Axon sheathed in endoneurium

Axons grouped into fascicles sheathed in perineurium

Fascicles grouped into a nerve sheathed in epineurium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In what situations might a peripheral nerve become entrapped?

A

Median nerve during carpal tunnel syndrome

Spinal root during intervertebral disc prolapse (i.e. sciatica)

Digital nerve in 2/3rd web spaces of foot during morton’s Neuroma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the different types of nerve trauma?

A

Direct (blow or laceration) vs indirect (Avulsion vs traction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is neurapraxia?

A

a temporary loss of motor/sensory function due to:

- Stretch/bruise –> Local ischaemia & Demyelination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Prognosis for neurapraxia?

A

Reversible, symptoms usually last 6-8wks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is axonotmesis?

A

Damage to a nerve axon but not the sheath

Stretch/crush/direct blow leads to wallerian degeneration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Whats the prognosis for axonotmesis?

A

Fair but worse than neurapraxia

Usually good but not full sensory recovery and less motor recovery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Whats is Neurotmesis?

A

Completely divided axon and sheath due to laceration or avulsion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Prognosis for Neurotmesis?

A

Poor. Can only recover with suturing & grafting

Plus theres a high risk of miswiring during regeneration

22
Q

Clinical features of peripheral nerve injury?

A
Dysaesthesia
Paresis/paralysis +/- wasting
Dry skin
Diminished/absent reflexes
UMN/LMN signs
23
Q

Describe the process of nerve healing?

A

Distal axon dies via wallerian degeneration

Then proximal axonal budding occurs after roughly 4 days and the nerve regenerates at ~1mm/day

24
Q

How do you assess the healing of a nerve?

A

Nerve conduction studies

Tinel’s Sign - Tap over a nerve, you will feel paraesthesia as far distally as the regeneration has spread

25
Q

What methods are there for repairing a nerve injury?

A

Bundle repair & growth factor when no tissue is lost

Nerve grafting when nerve is lost

26
Q

Describe the surgical rule of 3?

A

Immediate surgery within 3 days for clean/sharp injuries

Early surgery within 3 wks for blunt/contusion injuries

Delayed surgery after 3 months for closed injuries if there’s no recovery

27
Q

What cells make up tendons

A

A longitudinal arrangement of cells, mainly tenocytes.

28
Q

Describe the arrangement of collagen in a tendon?

A

Mostly type 1 collagen bundle surrounded by endotendon.

Bundles arranged into fascicles surrounded by paratendon

Fascicles bundled into a tendon surrounded by epitendon

29
Q

What happens if a tendon is underused?

A

Immobility leads to a low water & glycosaminoglycan concentration
This leads to poor strength

30
Q

List some tendon pathologies?

A
Degeneration
Inflammation
Enthesiopathy
Traction Apophysitis
Avulsion +/- bone fragment
Tear
Laceration/Incision
31
Q

Example of a degenerative tendon disorder and presentation?

A

Intrasubstance Mucoid Degeneration - common in the achilles

Can be asymptomatic but may be swollen, painful or tender

32
Q

Example and presentation of an inflammatory tendon disorder?

A

De Quervain’s Stenosing Tendonitis

Tendons of the EPB & APL get swollen, tender, hot and red. +ve for finklestein’s test

33
Q

What is enthesiopathy?

A

Inflammation at the insertion of a tendon to bone or muscle

E.g. Lateral Humeral Epicondylitis aka tennis elbow

34
Q

Whats an example of a traction Apophysitis?

A

Osgood Schlatter’s Disease

A recurrent load in adolescent active boys leads to inflammation at the patellar tendon as it inserts onto the Ant. Tibial Tuberosity

35
Q

How do we treat an avulsion?

A

Conservative - Retraction

Operative - Reattachment & fixation of the bone fragment

36
Q

What are the types of tendon tear?

A

Intrasubstance e.g. achilles

Or at Musculotendinous junction

37
Q

When does an achillis tear and how do we tell?

A

Most happen when sprint starting or jumping. Weight bearing forefoot push off whilst extending the knee.

+ve simmonds squeeze test and a palpable tender gap

38
Q

How do we treat a tendon tear?

A

Conservative - Mobilise + splint/cast

Operative - If the ends can’t be opposed

39
Q

Whats the function of a ligament?

A

to provide joint stability whilst maintaining ROM

Attached to bone on either side of a joint

40
Q

Compare a tendon to a ligament?

A

Ligaments have:

  • Less collagen
  • More proteoglycans/water
  • Less organized collagen
  • Rounder fibroblasts
41
Q

Describe the structure of a ligament?

A

Type 1 collagen
Fibroblasts
Sensory fibres that carry proprioception, stretch & sensory

42
Q

What are the phases of ligament rupture healing?

A

1) Haemorhagic Phase
2) Proliferative Phase
3) Remodelling Phase

43
Q

What happens during the haemorrhagic phase of ligament healing?

A

First a blood clot that is then resobed & replaced by Heavy Cellular Infiltrate

44
Q

What happens during the proliferative phase of ligament healing?

A

Scar tissue forms (disorganised collagenous CT)

45
Q

What happens during the remodelling phase of ligament healing?

A

Matrix becomes more ligament like

46
Q

When would we care for a ligament rupture conservatively?

A

A partial rupture with no instability

Or a patient that isn’t fit for surgery

47
Q

When would we care for a ligament rupture operatively?

A

If theres instability, expectation e.g. sportsmen or multiple ruptures

48
Q

How would we operatively treat a ligament rupture?

A

Repair
Augmentation
Replacement

49
Q

Name reasons for a delayed union? (delayed healing of a fracture)

A
  • High energy Injury
  • Instability
  • Infection
  • Steroids/immunosuppressants
  • Smoking
  • Warfarin
  • NSAIDS
  • Ciprofloxacin
  • Age
  • Radiotherapy
50
Q

Name some results of a non-union (complete failure of healing)

A
Instability
Calcification
Abundent calluses
Pain/tenderness
Persistant fracture line
Bone sclerosis