Orthopaedics- Trauma- The fracture process and fracture healing; Dislocations and Instability; Soft tissue injury Flashcards
(154 cards)
1
Q
What causes fractures?
What causes the majority of fractures?
A
Direct trauma (direct blow) Indirect trauma (due to twisting or bending forces). This causes the majority of fractures.
2
Q
What is an incomplete/unicortical fracture?
A
A fracture in which there is a break in continuity of only one cortex
3
Q
What is a complete fracture?
A
A fracture in which there is a break in continuity of both cortices.
4
Q
Give examples of causes of a) A high energy fracture and b) A low energy fracture
A
a) RTA, gunshot, blast, fall from height
b) Trip, fall, sports injury
5
Q
What are very low energy fractures usually due to?
A
An underlying weakness of the bone resulting in pathological fracture
6
Q
Name the two ways in which bone can heal
A
Primary healing and Secondary healing
7
Q
What is primary bone healing and when does it occur?
A
When there is minimal fracture gap (less than about 1mm)
The bone simply bridges the gap with new bone from osteoblasts.
This occurs in the healing of hairline fractures and when fractures are fixed with compression screws and plates
8
Q
What is secondary bone healing and when does it occur?
A
Secondary bone healing occurs in the majority of fractures, when there is a gap at the fracture site which needs to be filled temporarily to act as a scaffold for new bone to be laid down.
It involves an inflammatory response with recruitment of pluripotent stem cells which differentiate during the healing process.
9
Q
Describe the different stages of secondary bone healing.
A
After the fracture, haematome occurs with inflammation from damaged tissues.
Macrophages and osteoclasts remove debris and resorb the bone ends
Granulation tissue forms from fibroblasts and new blood vessels
Chondroblasts form cartilage (soft callus)
Osteoblasts lay down bone matrix (collagen type 1)- endochondral ossification
Calcium mineralisation produces immature woven bone (hard callus)
Remodelling occurs with organisation along lines of stress into lamellar bone
10
Q
When is a)soft callus and b) hard callus normally formed by?
A
a) 2nd to 3rd week
b) 6th to 12-th week
11
Q
What does secondary bone healing require?
A
A good blood supply for oxygen, nutrients and stem cells
A little movement or stress (compression or tension)
12
Q
What could be the result of a lack of blood supply, no movement (internal fixation with fracture gap), too big a fracture gap or tissue trapped in the fracture gap?
A
Atrophic non-union
13
Q
List some things which may impair fracture healing.
A
Smoking due to vasospasm
Vascular disease
Chronic ill health
Malnutrition
14
Q
What is hypertrophic non-union and why does it occur?
A
There is abundant hard callus formation but too much movement to give the fracture a chance to bridge the gap.
They occur due to excessive movement at the fracture site.
15
Q
What are the 5 basic fracture patterns?
A
Transverse fractures Oblique fractures Spiral fractures Comminuted fractures Segmental fractures
16
Q
What are transverse fractures?
A
Fractures that occur with pure bending forces One side (the convex side) fails in compression and the other (concave) side fails in tension.
17
Q
What are the effects of transverse fractures?
A
They may not shorten (unless completely displaced) but may angulate or result in rotational malalignment.
18
Q
What are oblique fractures?
A
Fractures that occur with a shearing force (e.g. a fall from a height, deceleration).
19
Q
How can oblique fracture patterns be fixed?
A
With an interfragmentary screw
20
Q
What are the effects of oblique fractures?
A
Shortening
Angulate
21
Q
What are spiral fractures?
A
Fractures that occur due to torsional forces
22
Q
How can spiral fractures be fixed?
A
With an interfragmenary screw
23
Q
What are spiral fractures most unstable to?
A
Rotational force
They can also angulate
24
Q
What are comminuted fractures?
A
Fractures with 3 or more fragments
25
What are comminuted fractures usually a reflection of?
A higher energy injury or poor bone quality.
26
What are the effects of comminuted fractures?
substantial soft tissue swelling
periosteal damage
reduced blood supply to the fracture site which may impair healing
27
Are comminuted fractures stable or unstable?
Very unstable. They tend to be stabilized surgically.
28
What are segmental fractures?
When the bone is fractured in two separate places.
29
How is a fracture of a long bone described?
According to the site of the bone involved (proximal, middle or distal third)
According to the type of bone involved (diaphyseal, metaphyseal or epiphyseal)
Intra-articular or extra-articular
30
What are intra-articular fractures at greater risk of?
Stiffness
Pain
Post-traumatic OA, particularly if there is any residual displacement resulting in an uneven articular surface
31
What does the position of a fracture depend on?
The degree of displacement and angulation
32
What is displacement?
Displacement describes the direction of translation of the distal fragment and is described using anatomical terms.
It can be estimated with reference to the width of the bone (25%, 50%, 75% displacement)
100% displacement is referred to as an "off-ended" fracture
33
That is the degree of angulation?
The degree of angulation describes the direction which the distal fragment points towards.
It is measured in degrees from the longitudinal axis of the diaphysis of a long bone.
34
What information does the degree of displacement and angulation of a fracture give?
It gives information about the direction of forces involved in an injury and about the reversed direction of forces required to reduce a fracture.
35
What are possible consequences of residual displacement or angulation?
Deformity
Loss of function
Abnormal pressure on joints leading to post-traumatic OA.
36
May minor degrees of displacement and angulation be acceptable?
Yes, depending on the bone involved and the site of the fracture.
37
What is the role of the periosteum in children's bones?
It serves to increase the width/circumference of growing long bones
38
What is the difference between the periosteum in children and in adults?
The periosteum in children is much thicker and tends to remain intact which can help stability and help reduction if required.
39
Do children's fractures heal more quickly or more slowly than adult's fractures?
Why?
They heal more quickly
| This is due to the thicker periosteum which is a rich source of osteoblasts.
40
What is a benefit of the large potential of children's bones to remodel?
Children can correct angulation up to 10 degrees per year of growth remaining in that bone.
Children's fractures are therefore surgically stabilised less often and greater degrees of displacement or angulation can be accepted.
41
When are fractures treated as an adult's fracture would be, due to the remodelling potential being less?
Once a child has reached puberty (around 12-14).
42
What do fractures around the physis have the potential to do?
What could this result in?
They have the potential to disturb growth.
| This could result in a shortened limb or an angular deformity if one side of the physis is affected by growth arrest.
43
What is the name of the classification system for physeal fractures?
Salter Harris clasisfication
44
What is a Salter-Harris I fracture?
A pure physeal separation. This carries the best prognosis and is least likely to result in growth arrest.
45
What are Salter-Harris II fractures?
Similar to Salter-Harris I but a small metaphyseal fragment is attached to the physis and epiphysis.
The likelihood of growth disturbance is low.
46
What are Salter-Harris III and IV fractures?
Intra-articular fractures, with the fracture splitting the physis.
III- splits the physis, no attached metaphysis
IV- splits the physis and attached fragment of metaphysis/diaphysis
There is greater potential for growth arrest with these.
47
How should Salter-Harris III and IV fractures be managed?
These fractures should be reduced and stabilized to ensure a congruent articular surface and minimize growth disturbance.
48
What is a Salter-Harris V injury?
A compression injury to the physis with subsequent growth arrest.
These cannot be diagnosed with initial X-Rays and are only detected once angular deformity has occurred.
49
What are the commonest physeal fractures?
Salter-Harris II fractures.
50
What should raise the suspicion of NAI (non-accidental injury) or child abuse?
Multiple fractures of varying ages (with varying amounts of callus or healing)
Multiple trips to A&E with different injuries
+ other features
51
What should happen to a child considered at risk of under suspicion of NAI?
They should be admitted for safety and a full examination of the child should be carried out, and skilled history taking from parents or carers should be performed by an experienced doctor.
52
List some clinical signs of a fracture
Localised bony (marked) tenderness- not diffuse mild tenderness
Swelling
Deformity
Crepitus- from bone ends grating with an unstable fracture
53
Which X-ray views should be requested to assess a fracture?
AP and lateral views
| Oblique views can be useful for complex shaped bones (e.g. scaphoid, acetabulum, tibial plateau)
54
What are used to diagnose mandibular fractures?
Tomograms- moving X-ray
55
When is CT useful in diagnosing fractures?
To assess fractures of complex bones
| Can help determine the degree of articular damage and help surgical planning for complex intra-articular fractures.
56
When is MRI useful?
To detect occult fractures (where there is clinical suspicion of fracture but a normal X-ray
57
When is Technetium bone scan helpful?
To detect stress fractures as these may fail to show up on xray until hard callus begins to appear.
58
List early local complications of fractures.
Compartment syndrome
Vascular injury with ischaemia
Nerve compression or injury
Skin necrosis
59
List early systemic complications of fractures
```
Hypovolaemia
Fat embolism
Shock
ARDS (acute respiratory distress syndrome)
Acute renal failure
SIRS (systemic inflammatory response syndrome)
MODS (multi-organ dysfunction syndrome)
Death
```
60
List late local complications of fractures
```
Stiffness
Loss of function
Chronic Regional Pain Syndrome
Infection
Non-union
Malunion
Volkmann's ischaemic contracture
Post traumatic OA
DVT
```
61
What is the main late systemic complication of fractures?
| When does this tend to occur?
Pulmonary embolism
| Tends to occur several days to weeks after injury but can occur much sooner
62
Is compartment syndrome a medical emergency?
Yes
63
What causes the rise of pressure in compartment syndrome secondary to a fracture?
Bleeding and inflammatory exudate from the fracture
64
What are the consequences of rising pressure in compartment syndrome?
The venous system is compressed resulting in congestion within the muscle and secondary ischaemia as oxygenated arterial blood cannot supply the congested muscle.
Nerve compression resulting in paraesthesiae and sensory loss.
65
How does muscle ischaemia manifest?
Severe pain
66
What is the cardinal clinical sign of compartment syndrome?
| What are other features?
Increased pain on passing stretching of the involved muscle.
| Other features: the limb will be tensely swollen and the muscle is usually tender to touch.
67
What is loss of pulses a feature of?
End stage ischaemia- the diagnosis has been made too late.
68
How is compartment syndrome managed?
Removal of any tight bandages may cause temporary relief
| Emergency fasciotomies involving incisions through skin and fascia to relieve constriction should be performed.
69
What will happen if ischaemic muscle is left untreated?
The ischaemic muscle will necrose resulting in fibrotic contracture (Volkmann's ischaemic contracture) and poor function.
70
How can vessels be damaged?
They can be stretched, compressed, torn or transected.
| Partial tears affecting the arterial intima can thrombose resulting in arterial occlusion.
71
What are two consequences of vascular injuries?
Distal limb ischaemia (risking subsequent amputation)
| Hypovolaemic shock
72
Which vessel is at risk of damage in the following injuries?
a) Knee dislocation
b) Paediatric supracondylar fracture of the elbow
c) Shoulder trauma
a) Popliteal artery
b) Brachial artery
c) Axillary artery
73
Fractures of which bone can be associated with life threatening haemorrhage from arterial or venous bleeding?
The pelvis
74
a) List signs of reduced distal circulation
| b) What should happen if these are present?
a) Reduced or absent pulses; pallor; delayed capillary refill; cold to touch
b) Urgent vascular surgery review and emergency surgical management.
75
How can the site of arterial occlusion be localized in theatre?
Urgent angiography
76
a) How can temporary restoration of circulation be achieved?
| b) What should be done additionally to protect the repair from shearing force?
a) With use of a vascular shunt
Vascular repair with either a bypass graft or endoluminal stent
b) Skeletal stabilization with internal or external fixation
77
How can ongoing haemorrhage from arterial injury in the pelvis be controlled?
With angiographic embolization performed by interventional radiologists
78
Which fractures are at high risk of infection?
Open fractures
79
How can open fractures occur?
Due to a spike of fractured bone from within puncturing the skin (inside out injury)
Due to laceration of the skin from tearing or penetrating injury (outside in injury)
80
What may infection at the fracture site result in?
Non-union
81
List factors which increase the risk of an open fracture becoming infected.
The higher the energy of the injury
The amount of contamination
Any delay in appropriate treatment
Problems with wound closure
82
What does the Gustilo classification describe?
The degree of contamination
The size of the wound
Whether the wound will be able to be closed or require plastic surgery cover
The presence of an associated vascular injury
83
Describe initial management of an open fracture in A&E.
IV broad spectrum antibiotics:
Flucloxacillin- gram positive organisms
Gentamicin- gram negative organisms
Metronidazole- anaerobes if there is soil contamination
A sterile or antiseptic soaked dressing should be applied to the wound to prevent further contamination before the fracture is splinted
84
What does surgical management of an open fracture involve?
Debridement: removal of all contamination and excision of non-viable soft tissue
Stabilized with internal or external fixation
85
Why must debridement of an open fracture be carried out?
Dead or devitalized tissue may serve to harbor infection with the immune system unable to access the devascularized tissues.
Additionally an unstable fracture may produce haematoma which acts as a culture medium for bacteria and may cause additional necrosis.
86
Why are open fractures difficult to treat in plaster cast?
Because frequent wound inspections are required.
87
How is the wound closed?
If wound not grossly contaminated, remaining skin and muscle is viable and wound can be closed without undue tension on skin edges: can be closed primarily.
Any wound that cannot be closed primarily: requires skin grafting, local flap coverage or free flap coverage.
88
Which type of skin grafting is usually used?
Split thickness skin grafting - SSG
89
a) Which tissues readily accept a skin graft?
b) Which other tissues will also accept a skin graft?
c) Which body tissues will not take accept a skin graft?
a) Muscle
Fascia
Granulation tissue
b) Paratenon (fatty or synovial material between a tendon and its sheath)
Periosteum
c) Bare tendon, bone, any exposed metal work
90
What should happen to the wound if there is any doubt over viability of soft tissues or if the wound is heavily contaminated?
It is usually safer to leave the wound open to allow ongoing infection to drain out and to return to theatre for further debridement in 48 hours as necrotic tissue will have declared itself by then.
The wound may be closed secondarily or plastic surfical flap coverage and/or skin grafting may be required.
91
In what scenarios may an injury (fracture) jeopardise the viability of overlying skin?
With higher energy injuries
| With fragile skin (e.g. due to age, steroids, rheumatoid arthritis)
92
What could the result of a protruding spike of bone or tension on the skin from deformity be?
Devitalisation and necrosis with skin breakdown
93
a) How does excessive pressure on the skin caused by a fracture manifest?
b) How should this be managed?
a) Tenting of the skin and blanching
| b) The fracture should be reduced as an emergency (under analgesia +/- sedation) to avoid subsequent necrosis
94
a) What could be the result of a shearing force on the skin?
b) How and when would this present?
c) How may it be treated?
a) Avulsion of the skin from its underlying blood vessels (de-gloving)
This can result in skin ischaemia and necrosis.
b) The skin will not blanch on pressure and may be insensate. The de-gloved area may take a few days to demarcate.
c) May require skin grafting or flap coverage
95
What is contusion?
Bruising
96
Why do fracture blisters occur?
Due to inflammatory exudates causing lifting of the epidermis of the skin.
97
Why is a surgical wound through swollen and contused skin and soft tissues not advisable?
The wound may not be able to be closed (leaving a route for subsequent infection).
Excessive tension on the wound may lead to necrosis and wound breakdown
98
Why are external fixators more appropriate than internal fixators in high energy tibia plateau fractures?
Due to excessive soft tissue swelling and contusions.
99
Why may it be wiser to perform early amputation in certain severe cases of mangled extremity?
To produce a more functional outcome
| To avoid multiple surgeries with which a poor result can be predicted.
100
After which fractures in particular may a DVT occur?
Pelvic or major lower limb fractures with a period of immobility.
101
How should a suspected DVT be managed?
Duplex scanning and anticoagulation
102
What is fracture disease?
A term used to describe stiffness and weakness due to the fracture and subsequent splintage in cast.
Most cases resolve over time and may be helped with physiotherapy.
103
Name factors upon which the time for a fracture to heal is dependent.
The energy of the injury (comminution, soft tissue damage)
Age of the patient
Health status of the patient
104
Which heals more quickly: metaphyseal fractures or cortical fractures?
Metaphyseal
105
What is a delayed union?
A fracture that has not healed within the expected time.
106
What can cause non union of a fracture?
Instability and excessive motion (hypertrophic non union)
Rigid fixation with a fracture gap, lack of blood supply to fracture site, chronic disease, soft tissue interposition (atrophic non union)
Infection (atrophic or hypertrophic non-union)
107
Which fractures are particularly prone to problems with healing due to poor blood supply?
Scaphoid wrist fractures
Fractures of the distal clavicle
Subtrochanteric fractures of the femur
Jones fracture of the 5th metatarsal
108
Why may some intra-articular fractures not unite?
| Give examples
Due to synovial fluid inhibiting healing if a fracture gap exists.
E.g intracapsular hip fracture, scaphoid fracture
109
Why will all implants ultimately break?
Fatigue failure
110
In which fractures may apposition of bone ends not be possible?
Comminuted fractures
111
What can be done to try and ensure subsequent union of a hypertrophic non-union?
Application of a plate to stabilise the fracture
112
How are atrophic non-unions managed?
Removal of fibrous tissue at the fracture site
Restoration of bleeding bone ends
Restoration of medullary canal continuity
Bone grafting to stimulate bone formation and to act as a scaffold for new bone to grow into
Internal or external fixation with compression across the fracture
113
What should be sought in any non-union?
| How should this be done?
Evidence of infection by CRP and bacteriological sampling.
114
What advantages do special circular frame external fixators have?
Applying compression at the fracture site
Ability to adjust alignment
Ability to lengthen the shortened bone
115
Can fractures unite if they are infected?
Yes, if they are suppressed.
116
a) How can acute infected fractures be suppressed?
| b) What else will need done for infections present for longer than a few weeks?
a) Antibiotic therapy with or without surgical washout
| b) The metalwork will need later removal.
117
List possible consequences of mal-unions.
Cosmetic deformity
Interference with function
Abnormal pressure on adjacent joints risking post-traumatic OA
118
Give examples of particularly poorly tolerated deformities.
Internal rotation of tibia: leads to awkward gait
Volar angulation of distal radius: leads to very poor grip strength
Mal-united Colles fractures can result in weakness, stiffness and chronic pain
119
How can significant mal-union be corrected?
Osteotomy
Acute correction held in place with plate and screws or with a circular external fixator (which can be adjusted as necessary)
120
a) Which fractures are prone to developing avascular necrosis?
b) How are these managed?
a) Fractures of the femoral neck, scaphoid and talus
b) Femoral neck: Total hip replacement
Scaphoid and talus: arthrodesis of wrist and ankle
121
Are all cases of AVN symptomatic?
No
122
a) What can cause post-traumatic OA?
| b) How can this be treated?
a) Intra-articular fracture
Ligamentous instability
Fracture malunion
b) Analgesia, bracing/splinting, arthrodesis, joint replacement
123
What is chronic regional pain syndrome?
A poorly understood heightened chronic pain response after injury
124
List some characteristics of CRPS
```
Variable, but include:
Constant burning or throbbing
Allodynia
Chronic swelling
Stiffness
Painful movement
Skin colour changes
```
125
Which type of CRPS is caused by a peripheral nerve injury, type 1 or type 2?
Type 2
126
How is CRPS managed?
```
Specialist pain services
Pharmacological agents: analgesics, antidepressants (amitriptyline), anticonvulsants (gabapentin), steroids.
TENS machines
Physiotherapy
Lidocaine patches
Sympathetic nerve blocking injections
```
127
What is the principle late systemic complication of fractures, particularly after pelvic or lower limb fracture?
Pulmonary embolism
128
What should assessment of an injured limb include?
Assessment of whether the injury is open or closed
Assessment of the distal neurovascular status
Whether there is compartment syndrome present
Assessment of the status of the skin and soft tissue envelope
129
How is the distal neurovascular status of a limb assessed?
```
Pulses
Capillary refill
Temperature
Colour
Sensation
Motor power
```
130
What does initial management of a long bone fracture involve?
Clinical assessment of the injured limb
Analgesia (usually IV morphine)
Splintage/immobilization of the limb
Investigation (usually X-rays)
131
How may a limb be splinted/immobilized?
A temporary plaster slab known as a backslab
A sling
An orthosis
Thomas splint for femoral shaft fractures
132
In which cases should reduction of the fracture be performed before waiting for X-rays?
If a fracture is grossly displaced
If there is in obvious fracture dislocation
If there is a risk of skin damage from excessive pressure
133
What is a)open reduction and b) closed reduction?
a) Method of reduction in which the fracture fragments are exposed by dissecting the tissues
b) Method of reduction in which the bone fragments are manipulated without surgical exposure of the fragments.
134
a) Which fractures are treated non-operatively?
| b) How are they managed?
a) Undisplaced fractures
Minimally displaced fractures
Minimally angulated fractures
Must be considered to be stable
b) A period of splintage or immobilization then rehabilitation
135
Which fractures required reduction under anaesthetic?
Displaced or angulated fractures where the position is deemed unacceptable
136
List three ways in which extra-articular diaphyseal fractures can be fixed?
ORIF- open reduction and internal fixation
Closed reduction and indirect internal fixation with an intramedullary nail with dissection distant to the fracture site
External fixation
137
What is the aim of ORIF?
Anatomic reduction and rigid fixation leading to primary bone healing
138
Why may it be preferable to avoid ORIF in some extra-articular diaphyseal fractures?
If the soft tissues are too swollen
If the blood supply to the fracture site is tenuous
Where ORIF may cause extensive blood loss (e.g. femoral shaft)
If plate fixation may be prominent (e.g. tibia)
139
What is the aim of closed reduction and indirect internal fixation with an intramedullar nail with dissection distant to the fracture site?
Functional reduction and stable fixation allowing micromotion required for secondary bone healing
140
What does external fixation aim for?
Secondary bone healing
141
a) How should displaced intra-articular fractures be managed?
b) How may fractures involving a joint with predictable poor outcome be treated?
a) Anatomic reduction and rigid fixation by way of ORIF using wires, screws and plates.
b) With joint replacement or athrodesis
142
Why may elderly patients be more likely to be treated non-operatively?
Elderly patients with co-morbidities, osteoporosis and dementia are at higher risk of complications of surgery, failure of fixation and failure to rehabilitate satisfactorily.
They also tend not to have as high a functional demand.
143
Do all fractures require follow up X-rays to confirm if they are healing?
No, particularly extra-articular cancellous bone fractures.
| For many, evidence of healing is determined by clinical assessment
144
What are symptoms and signs of fracture healing?
Resolution of pain and function
Absence of point tenderness
No local oedema
Resolution of movement at fracture site
145
What are clinical signs of non-union?
Ongoing pain
Ongoing oedema
Movement at the fracture site
146
What imaging can help confirm if a fracture is healing?
Bridging callus may be see on X-ray
| In cases where doubt exists over bony union, CT scans man confirm or exclude bridging callus.
147
How can ligaments and tendons be damaged?
They can be sprained (intra-substance tearing of some fibres), partially torn or completely ruptured.
148
How can muscle tears occur?
With rapid resisted contraction.
149
How are ligament ruptures graded?
Grade 1- sprain
Grade 2- partial tear
Grade 3- complete tear
150
What is the mainstay of treatment for most soft tissue injuries?
RICE- rest, ice, compression, elevation to reduce initial swelling
Followed by early movement to prevent stiffness
151
a) What can some complete ligament ruptures result in?
| b) How can they be managed?
a) Joint instability
| b) They may need repair, tightening (advancement) or graft reconstruction
152
Which tendon tears need surgical repair?
Complete tears of tendons fundamental for function : quadriceps tendon, patellar tendon
153
Which complete tendon tears can be managed conservatively?
Achilles tendon
Rotator cuff
Long head of biceps brachii
Distal biceps
However repair may be warranted to restore function.
154
Which tendons are commonly divided?
Flexor and extensor tendon injuries in the hand and wrist
| They usually require surgical repair.
