Growth, Injury and Repair

Question 1

What is a tendon?

Answer 1

Longitudinal arrangement of cells (mostly tenocytes) and fibres (collagen type 1 triple helix)

Question 2

What is the structure of a tendon?

Answer 2

Collagen bundles covered by endotenon
Fascicles covered by paratenon
Tendon covered by epitenon

Question 3

In what layers is the blood supply to a tendon found?

Answer 3

Paratenon

Question 4

What types of injuries can occur to a tendon?

Answer 4

Degeneration 
Inflammatory 
Enthesiopathy 
Traction apphysitis 
Avulsion +/- bone fragment 
Tear- intrasubstance (rupture) 
Tear- musculotendinous junction 
Laceration/incision  
Crush/ischameia/attrition 
Nodules

Question 5

What is a common area of tendon degeneration?

Answer 5

Achilles tendon

Question 6

What is de Quervain’s stenosing tenovaginitis?

Answer 6

Inflammation of tendons of EPB and APL passing through common tendon sheath at radial aspect of wrist

Question 7

What are the symptoms and signs of de Quervain’s?

Answer 7

Swollen 
Tender 
Hot 
Red 
Positive Finklestein's test

Question 8

What is enthesiopathy?

Answer 8

Inflammation at insertion to bone of muscle, tendon or ligament

Question 9

What is an example of traction atophysitis?

Answer 9

Osgood Schlatter’s disease

Question 10

What is Osgood Schlatter’s disease?

Answer 10

Insertion of patellar tendon into anterior tibial tuberosity

Question 11

What group are commonly affected Osgood Schlatter’s disease?

Answer 11

Adolescent active boys

Question 12

What is mallet finger?

Answer 12

Insertion of extensor tendon into dorsum of base of distal phalanx of finger, causing forced flexion of extended finger

Question 13

What is the treatment for avulsion?

Answer 13

Conservative (Limited application, retraction tendon)

Operative (Reattachment tendon, bone fixation)

Question 14

Why does avulsion occur?

Answer 14

Load exceeding failure strength while muscle contracting

Question 15

How does intrasubstance rupture?

Answer 15

Load exceeds failure strength

Question 16

What are common mechanisms of rupture?

Answer 16

Pushing off with weight bearing forefoot whilst extending knee joint
Unexpected dorsiflexion of ankle
Violent dorsiflexion of plantar flexed foot

Question 17

What are the clinical signs of a ruptured achilles tendon?

Answer 17

Positive Simmonds (squeeze) test 
Palpable tender gap

Question 18

What is the treatment for a rupture?

Answer 18

Conservative (Mobilise, Splint/cast)

Operative

Question 19

What are common areas for laceration to occur?

Answer 19

Finger flexors (FDS and FDP)

Question 20

What are ligaments?

Answer 20

Dense bands of collagenous tissue anchored to a bone at either end

Question 21

How are ligaments different from tendons?

Answer 21

Lower percentage of collagen
Higher percentage of proteoglycans and water
Less organised collagen fibres
Rounder fibroblasts

Question 22

What are the healing phases of a ligament?

Answer 22

Haemorrhage
Proliferative phase
Remodelling

Question 23

What occurs during the haemorrhage phase of ligament healing?

Answer 23

Blood clot reabsorbed
Replaced with a heavy cellular infiltrate
Hypertrophic vascular response

Question 24

What occurs during the proliferative phase of ligament healing?

Answer 24

Production of scar tissue

Disorganised collagenous connective tissue

Question 25

What occurs during the remodelling phase of ligament healing?

Answer 25

Matrix becomes more ligament like | Major differences in composition, architecture and function persist

Question 26

What is a peripheral nerve?

Answer 26

The part of the spinal nerve distal to the nerve roots

Question 27

What is the structure of a peripheral nerve?

Answer 27

Axons covered with endoneurium and grouped into fascicles, covered in perineurium and grouped to form nerves which are covered in epineurium

Question 28

What type of compression injuries can occur to nerves?

Answer 28

Entrapment Carpal Tunnel syndrome Sciatica Morton's neuroma

Question 29

What kind of traumatic injuries can occur to nerves?

Answer 29

``` Direct (blow, laceration) Indirect (avulsion, traction) Neurapraxia Axonotmesis Neurotmesis ```

Question 30

What is neurapraxia?

Answer 30

Nerve in continuity Stretched or bruised Reversible conduction block, local ischaemia and demyelination

Question 31

What is axonotmesis?

Answer 31

Endoneurium intact but disruption of axons, more severe injury Stretched, crushed or direct blow Wallerian degeneration follows

Question 32

What is neurotmesis?

Answer 32

Complete nerve division Laceration or avulsion No recovery unless repaired Endoneural tubes disrupted sp high chance of 'miswiring' during regeneration

Question 33

What is a closed nerve injury?

Answer 33

Associated with nerve injuries in continuity with possible spontaneous recovery

Question 34

What is an open nerve injury?

Answer 34

Frequently related to nerve division Treated with early surgery Distal portion of nerve undergoes Wallerian degeneration

Question 35

What are the sensory clinical features of nerve injuries?

Answer 35

Dysaethesiae (anaesthetic, paraesthetic, hypo/hyper aesthetic)

Question 36

What are the motor clinical features of nerve injuries?

Answer 36

Paresis or paralysis +/- wasting | Dry skin

Question 37

What other clinical features may be present with nerve injuries?

Answer 37

Reflexes absent or diminished

Question 38

What is Tinel's sign?

Answer 38

Tap over site of nerve and paraesthesia will be felt as far as distally as regeneration has progressed

Question 39

What surgical options are available for nerve repair?

Answer 39

Direct repair | Nerve grafting

Question 40

What is the "rule of three" for nerve repair?

Answer 40

Immediate surgery within 3 days for clean and sharp injuries Early surgery within 3 weeks for blunt/contusion injuries Delayed surgery 3 months after injury for closed injuries

Question 41

What are the clinical signs of an upper motor neurone injury?

Answer 41

``` Decreased strength Increased tone Increased deep tendon reflexes Clonus present Babinski's sign present Absent atrophy ```

Question 42

What are the clinical signs of a lower motor motor neurone injury?

Answer 42

``` Decreased strength Decreased tone Decreased deep tendon reflexes Clonus absent Babinski's sign absent Present atrophy ```

Question 43

What is a bone fracture?

Answer 43

Break in structural continuity of bone, may be a crack, break, split, crumpling or buckle

Question 44

Why do bones fail?

Answer 44

High energy transfer in normal bones Repetitive stress in normal bones Low energy transfer in a normal bones

Question 45

What are the stages of fracture repair?

Answer 45

Inflammation Soft callus Hard callus Bone remodelling

Question 46

What occurs during the inflammation stage of fracture repair?

Answer 46

``` Haematoma and fibrin clot Platelets, PMNs, Neutrophils, Monocytes Fibroblasts Mesenchymal and osteoprogenitor cells Angiogenesis ```

Question 47

What is the time frame for the soft callus phase of fracture repair?

Answer 47

Begins when pain and swelling subside | Lasts until bony fragments are united by cartilage or fibrous tissue

Question 48

What occurs during the hard callus stage of fracture repair?

Answer 48

Conversion of cartilage to woven bone | Increasing rigidity

Question 49

What occurs during the bone remodelling stage of fracture repair?

Answer 49

Conversion of woven bone to lamellar bone Medullary canal is reconstituted Bone responds to loading characteristics Wolff's law

Question 50

What is delayed union?

Answer 50

Failure to heal in expected time

Question 51

What are some of the caused of delayed union?

Answer 51

``` High energy injury Distraction (increased osteogenic jumping) Instability Infection Steroids Immune suppressants Smoking Warfarin NSAID Ciprofloxacin ```

Question 52

What alternative management methods should be considered for delayed healing?

Answer 52

Different fixation Dynamisation Bone grafting