19. Disorders Of The Foot And Ankle Flashcards
(109 cards)
1
Q
What are compartments of the limbs bound by?
A
bound by bone and deep fascia
2
Q
What is compartment syndrome?
A
Trauma (blunt or penetrating) to a fascial compartment may lead to haemorrhage and/or oedema and cause a rise in intracompartmental pressure
3
Q
What are the clinical signs of compartment syndrome?
A
- severe pain in the limb which is excessive for the degree of injury
- increasing and not relieved by analgesia
- the pain is classically exacerbated by passive stretch of the muscles
4
Q
How is compartment syndrome treated?
A
fasciotomy (surgical decompression)q
5
Q
What are early short term consequences of compartment syndrome?
A
- Decreased perfusion of muscle
- Ischaemic muscle releases mediators which further increase capillary permeability and exacerbate the rise in intracompartmental pressure
In severe untreated cases:
- rhabdomyolysis
- acute kidney injury can result.
Later neurovascular signs
6
Q
What are the late short term consequences of compartment syndrome?
A
If the compartment pressure exceeds the systolic arterial pressure:
- loss of peripheral pulses
- increased capillary refill time.
Nerve fibres are susceptible to ischaemia
7
Q
Which nerves are affected first in compartment syndrome and what is the implication of this?
A
Thin cutaneous nerve fibres are affected more quickly than the motor fibres, so distal paraesthesia precedes loss of motor function.
8
Q
What are the long term consequences of compartment syndrome?
A
- rhabdomyolysis can result in acute kidney injury which may become chronic
- necrotic muscle may also undergo fibrosis leading to Volkmann’s ischaemic contracture
9
Q
What is Volkmann’s ischaemic contracture?
A
a permanent painful and disabling contracture of the affected muscle groups
10
Q
What is the typical mechanism injury for ankle fracture?
A
Inversion or eversion injury
11
Q
What is important to consider in fractures?
A
co-morbidities (e.g. diabetes, neuropathy, peripheral vascular disease, smoking) as these are likely to affect fracture healing
12
Q
What needs to be done if fracture blisters appear?
A
Surgery often needs to delayed until after the blisters have healed. Sometimes the skin over the fracture blister becomes necrotic, so healing can take a considerate amount of time
13
Q
What are open ankle fractures?
A
skin barrier is breached and there is a direct communication between the fracture and the external environment
14
Q
How is the risk of osteomyelitis(infection of the bone) reduced in open ankle fractures?
A
Require urgent surgery with extensive irrigation and debridement
15
Q
What is wound irrigation?
A
steady flow of a solution across an open wound surface to achieve wound hydration, to remove deeper debris, and to assist with the visual examination
16
Q
What is debridement?
A
removal of damaged tissue or foreign objects from a wound.
17
Q
What do different part of the ankle ring ( ankle joint and associated ligaments) represent?
A
- proximal part of the ring: articular surfaces of the tibia and fibula, united at the inferior tibiofibular joint by syndesmotic ligaments.
- medial side: formed by the medial (deltoid) ligament
- inferior part: formed by the subtalar joint
- lateral side: formed by the lateral ligament complex of the ankle (anterior talofibular, talocalcaneal and posterior talofibular)
18
Q
What is important to remember in ankle fractures with regard to numbers of structures damaged?
A
When there is a fracture, likely to be more than one structure that is damaged (another bone, or ligaments, usually on the opposite side) (can’t break a ring in one place)
19
Q
What other structures may be damaged in an injury that results in either forced eversion or external rotation of the foot?
A
an injury that results in either forced eversion or external rotation of the foot will push against the lateral malleolus, potentially leading to an oblique fracture of the lateral malleolus, and will pull on the medial ligaments, leading to a ruptured deltoid ligament or a transverse fracture of the medial malleolus
20
Q
What other structures may be damaged in an injury that results in either forced forced adduction or inversion of the foot?
A
an injury that results in either forced adduction or inversion of the foot can push the medial malleolus off the tibia (oblique fracture) and pull on the lateral structures, leading to ruptured lateral ligaments or a transverse fracture of the lateral malleolus.
21
Q
What is a talar shift?
A
Talus shifts medially or laterally within the ankle joint
22
Q
Disruption of which ligaments causes talar shift?
A
Disruption of any two out of the syndesmosis, medial (deltoid) or lateral ligamentss, the ankle mortise becomes unstable and widens so that the talus can shift medially or laterally within the ankle joint
23
Q
How are stable ankle joints treated?
A
Non-operatively with an aircast boot or a fibreglass cast for comfort - can weight-bear safely and there is a low rate of complications such as secondary osteoarthritis
24
Q
How are non-stable ankle joints treated?
A
need surgical stabilisation
25
What does an ankle sprain refer to?
Partial or complete tear of one or more ligaments of the ankle joint
26
How are ankle sprains treated?
- 90% heal with rest and time
| - those that do not heal can cause late ankle instability and sometimes require surgery
27
What factors can contribute to an increased risk of ankle sprains?
- Weak muscles/tendons that cross the ankle joint, especially the peroneal muscles
- Weak or lax ankle ligaments - this can be hereditary or due to overstretching of ligaments as a result of repetitive ankle sprains
- Inadequate joint proprioception (i.e. sense of joint position)
- Slow neuromuscular response to an off-balance position
- Running on uneven surfaces
- Shoes with inadequate heel support
- Wearing high-heeled shoes - due to the weak position of the ankle joint with an elevated heel, and a small base of support
28
What are the most common mechanisms for ankle sprains?
Ankle sprains occur usually through excessive strain on the ligaments of the ankle. This can be caused by Excessive external rotation, inversion or eversion of the foot due to an external force
When the foot is forced past its normal range of motion, the excess stress puts a strain on the ligaments. If the strain is great enough to pull a ligaments past its yield point, the ligament becomes damaged or ‘sprained’
29
Which ligament is most commonly affected in ankle sprain and what is the mechanism for this?
anterior talofibular ligament: inversion injury affecting a plantar-flexed and weightbearing foot.
30
What is an avulsion fracture?
A tendon or ligament is placed under tension and instead of the tendon or ligament tearing, a fragment of bone is pulled off at the insertion site
31
What common avulsion fracture occurs in severe ankle sprains and why?
Fifth metatarsal tuberosity avulsion:
Peroneus (fibularis) brevis tendon is attached to a tubercle on the base of the 5th metatarsal. In an inversion injury, it is under tension and can pull off a fragment of bone at its insertion site
32
What might a 5th metatarsal avulsion fracture be confused for in children?
Unfused apophysis
33
What mechanisms can cause achilles tendon rupture?
- Making a forceful push-off with an extended knee (e.g. during jumping)
- A fall with the foot outstretched in front and the ankle dorsiflexed, forcibly overstretching the tendon
- Falling from a height, or abruptly stepping into a hole or off a kerb.
34
What is the common site on the achilles tendon for rupture and why?
'Vascular watershed' area, approximately 6cm proximal to the insertion of the Achilles tendon
- area of decreased vascularity and thickness
35
What is more common in achilles tendon rupture, complete or partial tear?
complete
36
What are the signs and symptoms of achilles tendon rupture?
- A sudden and severe pain at the back of the ankle or in the calf (like being 'kicked in the heel')
- The sound of a loud pop or snap
- A palpable (and sometimes visible) gap or depression in the tendon
- Initial pain and swelling followed by bruising
- Inability to stand on tip toe or to push-off whilst walking
37
What is the Thompson's test?
Used to evaluate achille's tendon, squeeze calf, result is positive if there's no movement
38
Why is surgical reconstruction of tendon ruptures difficult?
When the tendon ruptures, Two ends are frayed (like a mop head)
39
How are most Achilles tendon ruptures treated and why?
Treated conservatively, with the foot being held in the correct position in an aircast boot
- surgical reconstruction is difficult
40
What is the complication rate of achilles tendon surgery and why?
5-10% of patients have wound complications because the overlying skin is thin and poorly vascularised
41
What is the rate of re-repture of Achilles tendon?
2-8% after surgery with a
| similar rate after conservative management
42
What is hallux valgus?
- Varus deviation of the first metatarsal
- Valgus deviation and/or lateral rotation of the hallux
- Prominence of the first metatarsal head, with or without an overlying callus
43
Define hallux valgus
Hallux (big toe) valgus (distal part deviated laterally)
44
What is the most common cause of a 'bunion' (bony deformity at the 1st MTPJ)?
Hallux valgus
45
What can hallux valgus occur secondary to?
Trauma
Arthritic/metabolic conditions:
- gout
- rheumatoid arthritis
- psoriatic arthritis
Connective tissue disorders that cause ligamentous laxity
-e.g. Ehlers-Danlos syndrome
46
Do high-heeled shoes or tight-fitting shoes cause hallux valgus
no
However, such footwear can exacerbate it if it is already present by keeping the hallux in valgus deviation
47
What might explain why bunions tend to ‘run in families’?
The association with ligamentous laxity
48
Why should surgery for hallux valgus not be done purely for cosmetic reasons?
may convert a foot that is painless into a foot that is painful
49
What does surgery for hallux valgus involve?
Metatarsal osteotomy and realigning the fragments. A similar osteotomy may also be needed in the proximal phalanx of the great toe
50
What is hallux rigidus?
Osteoarthritis of the 1st metatarsophalangeal joint (MTPJ), resulting in stiffness of this joint
51
Why is the first MTPJ prone to developing OA?
With each step, a force equivalent to twice the body weight passes through this very small joint
52
What are secondary causes of hallux rigidus?
Gout and previous septic arthritis
53
What are the signs & symptoms of hallux rigidus?
- pain in the MTPJ on walking
- and on attempted dorsiflexion of the toe
- severe cases have pain at rest
- dorsal bunion
- restricted dorsiflexion
54
How do patients with hallux rigidus compensate for the pain?
By walking on the outside of their
| foot (i.e. inverting the foot and walking on the lateral border)
55
How does Hallux rigidus affect the range of dorsiflexion and plantar flexion of the 1st MTPJ?
The range of dorsiflexion of the toe becomes severely restricted due to the arthritis, although plantar flexion is usually retained
56
Define athroplasty.
joint replacement
57
Define arthrodesis.
joint fusion
58
What is excision arthroplasty?
Surgical removal of the joint with interposition of soft tissue (e.g. a rolled-up tendon, between the bone ends)
59
Define osteotomy.
Surgical cutting of a bone to allow realignment (to take the load of the affected part of the joint)
60
What is the initial treatment for hallux rigidus?
activity modification, analgesia, orthotics or aids and sometimes intra-articular steroid injections
61
What is an orthosis?
an externally applied device used to modify the structural and functional characteristics of the neuromuscular and skeletal system
62
Give an example of a orthotic that can used for hallux rigidus?
Rigid sole orthotic is a very stiff shoe insert:
- prevents motion at the 1st MTPJ.
- This will help prevent the pain caused by dorsiflexion of the toe whilst walking
63
What is the gold standard surgical treatment for hallux rigidus If conservative management fails to control
the symptoms sufficiently?
arthrodesis (fusion) of the 1st MTPJ
64
What does arthrodesis of the 1st MTPJ involve?
Joint is excised so that it is effectively replaced by a 'fracture'. The 'fracture' is then stabilised
with screws and normal fracture healing subsequently fuses the joint
65
What is the major differnce between OA of the hip and ankle?
Nearly all cases of OA of the ankle are secondary arthritis
66
What is the major cause of ankle OA?
70-80% of cases occur in a joint that has previously suffered trauma (e.g. fracture, severe sprain)
- post traumatic arthritis
67
What are the causes of ankle OA?
- post traumatic
- secondary to inflammation (rheumatoid arthritis, reactive arthritis)
- joint stress, obesity
- non-identifiable cause (primary ankle arthritis)
68
How do Patients with primary OA of the
| ankle differ from patients with secondary OA of the ankle?
Patients with primary OA of the ankle tend to be older, experience less pain, and have a better range of motion than those with secondary OA.
69
What is the gold standard surgical treatment for ankle OA?
arthrodesis
70
Is movement retained in ankle arthrodesis?
Patients can walk very well after an ankle fusion as they still have mobility of the mid-foot and fore-foot. There is often no discernible limp
71
What are the risks of ankle athroplasty?
Prosthetic loosening and prosthetic infection
72
What are 4 different types of toe deformities in the lesser toes?
Claw toe, mallet toe, hammer toe, curly toe
73
What is claw toe and which toes does it affect?
hyperextended at the MTPJ and flexed at the PIP joint (and sometimes also at the DIP joint so that the toe curls under the foot). Corns may develop over the
dorsum of the toe or under the head of the metatarsal.
- usually all 4 lesser toes at the same time
74
What causes claw toe?
muscle imbalance which causes the ligaments and tendons to become unnaturally tight. This is usually due to neurological damage
75
What may claw toe occur secondary to?
Cerebral palsy, stroke, diabetes or
alcohol dependence
Trauma, inflammation and rheumatoid arthritis can also cause claw toe
76
What is hammer and mallet toe and which toe are they most common in?
Hammer: flexed at PIPJ
Mallet: felxed at DIPJ
- can affect any toe but are most common in second toe
77
What can cause hammer or mallet toe?
Ill-fitting pointed shoes, and pressure on the second toe from an adjacent hallux valgus
78
How can a tight fitting shoe cause a hammer or mallet toe?
Tight shoe causes a toe to stay in a flexed position for too long, the muscles contract and shorten. This makes it harder to extend the toe. Over time, the muscles cannot extend the toe, even when the shoes are not being worn.
79
What type of condition is curly toes and which toes does it affect?
- congenital
- usually involve the 3rd to 5th digits
- bilateral
80
What causes curly toes?
Thought to develop because the tendons of the flexor digitorum longus (FDL) or flexor digitorum brevis (an intrinsic muscle of the foot) are too tight.
81
What is the treatment for curly toes?
Most children are asymptomatic. Treatment is usually conservative with passive extension of the toes and stretching of the flexor tendons.
82
When is surgery considered for curly toes?
After the age of 6 years in children whose curly toes cause them pain on activity
83
What is achilles tendinopathy?
degenerative not an inflammatory process
Although the Achilles tendon can withstand great stress from running and jumping, it is also prone to tendinopathy or degenerative change.
84
At what point of the tendon can tendinopathy develop?
- point of insertion of the Achilles tendon into the calcaneum (insertional tendinopathy)
- vascular 'watershed' area within the Achilles tendon (non insertional tendinopathy)
85
What are the signs and symptoms of Achilles tendinopathy?
- Pain and stiffness along the Achilles tendon in the morning
- Pain in the tendon or at the back of the heel that worsens with activity
- Severe pain 24 hours after exercising
- Thickening of the tendon
- Swelling that is present all of the time but worsens during activity
- A palpable bone spur (in insertional tendinopathy)
86
In which individuals does Achilles tendinopathy tend to occur in?
- overuse (long distance runners, sprinters, especially with poor training regimens)
- can occur in disuse
- obese
- diabetic
87
What is the treatment for Achilles tendinopathy and how does this help?
Physiotherapy, especially eccentric stretching exercises, to try and improve the vascularity of the tendon and promote healing
88
What is pes planovalgus?
```
Flat foot
(Pes = foot; Plano = flat; Valgus = lateral angulation of the distal part)
```
89
What has happened in flat feet?
Medial arch of the foot has collapsed so that the medial border of the foot almost touches the ground. Valgus refers to the valgus angulation of the hindfoot
90
Is flat feet normal in children an why?
Yes,
- arches have not yet developed
- there is also a large amount of subcutaneous adipose tissue in the sole of the foot (medial fat pad)
- It is only if the deformity persists into adolescence, or recurs during or after adolescence, that it is considered abnormal
91
When does the medial longitudinal arch begin to form?
around the age of 5 years
92
Should orthotics be prescribed for flat feet?
No, they are ineffective in promoting the normal development of the arch
93
What are flexible flat feet?
- no medial arch whilst standing normally
- but when standing on tip-toes, a normal medial arch appears
- the hindfoot returns from valgus deviation into a normal alignment
94
What are rigid flat feet?
Unlike flexible flat feet, always appear abnormal
- no arch appears on tiptoe, hindfoot remains valgus
- Rigid flatfoot is often symptomatic and therefore requires treatment
95
What causes rigid flat feet?
Tarsal coalition (failure of the tarsal bones to separate during embryonic development
96
What does adult acquired flat foot result from?
Dysfunction of the tibialis posterior tendon, which usually supports the medial longitudinal arch of the foot whilst walking
97
Who does adult acquired flatfooot usually occur in and what do they complain of?
Middle-aged females; they give a history of a change in shape of their foot and often describe pain behind the medial malleolus
98
What are risk factors for adult acquired flatfoot?
obesity, hypertension and diabetes
99
When might adult acquired flatfeet occur temporarily?
During pregnancy, due to increased laxity of the ligaments
100
How is adult acquired flatfoot treated?
- 80% orthotics (insoles) to support their medial arch and physiotherapy to improve muscle strength
- some surgical reconstruction
- if OA developed, athrodesis of joints of the hindfoot
101
How many diabetic patients are affected by foot disease?
15%
102
What is foot disease due to in diabetic patients?
- loss of sensation due to peripheral neuropathy
- ischaemia due to peripheral arterial disease and microvascular disease
- immunosuppression due to poor glycaemic control
- can lead to foot ulcers, severe infections and other serious complications.
103
Why is the foot disease exacerbated in diabetic patients?
loss of protective sensation, the patients will often continue to weight-bear on very significant soft tissue abnormalities
104
What is Charcot athroplasty?
- Progressive destruction of the bones, joints and soft tissues - due to Poorly-controlled diabetes
- most commonly involves the ankle and foot, but can affect other joints such as the knee.
105
What happens in charcot athroplasty?
Combination of neuropathy, abnormal loading of the foot, repeated microtrauma (with non healing microfractures), and metabolic abnormalities leads to inflammation causing osteolysis (bone resorption), fractures, dislocation and deformity
106
What are the effects of neuropathy in charcot athroplasty?
- reduced ability to detect touch,
temperature, and pain
- muscle spasticity (e.g. tight Achilles tendon), which exacerbates the deformity
107
What develops in severe cases of Chrocot athroplasty?
A rocker-bottom foot may develop
108
What is the treatment for Charcot athroplasty and why is it difficult?
- Comprises optimisation of glycaemic control and reduction of the load placed on the affected joints.
- However, this can be challenging as there is reduced
bone stock and the bones are soft (due to inflammation).
- The patients often do not experience pain, so are not reminded to stop weight-bearing on the foot.
- also often obese which increases the load placed through their softened bones
-usually have poor glycaemic control and therefore have secondary immunosuppression
109
what action is taken to reduce the liklhood of chrocot arthroplasty in diabetic patients?
- patients with diabetes attend regular ‘diabetic foot clinics’ for screening.
- feet will be checked for any corns, callouses, cracks and dry skin.
- Sensation and perfusion of the feet are assessed
and their shoes are checked to make sure that they are suitably protective against trauma (strong soles, not open-toed) and that they fit well (e.g. are not
rubbing).
- Patients are educated on how to look after their feet and reduce the chance of complications. #
- Tight glycaemic control is also emphasised as being
important in preventing the development of neuropathy and vascular disease and in maintaining a healthy immune response.
