Week 36- Lower Limb and Soft Tissue Flashcards
1
Q
What are some haemodynamic changes in response to exercise?
A
- Increase –> HR, SV, CO
- Redistributed blood flow
- Blood mobilised from venous pools
2
Q
What are some respiratory changes in response to exercise?
A
- Increase –> Tidal volume, respiratory rate and minute ventilation
- Bronchodilation
3
Q
What is the change in the blood in response to exercise and why?
A
Blood glucose increased –> energy required by muscles
4
Q
What is some renal changes in response to exercise?
A
Reduction in renal blood flow and GFR
Increased reabsorption of NaCl and water
5
Q
What is some thermoregulation undertaken during exercise?
A
Increased dissipation of heat via sweat evaporation
6
Q
What is Stroke volume? SV
A
Blood volume ejected from each ventricle (its equal for each) during a single cardiac contraction
At rest 60-80mL –> exercise can boost to 180mL
7
Q
What is Cardiac output and its formula?
A
The amount of blood pumped per minute:
CO = HR x SV
8
Q
Is heart rate and stroke volume altered by physical health training by athletes etc?
A
Stroke volume increases a lot with training
HR –> returns to rest quicker
9
Q
How does muscle contraction shift venous pooled blood to the heart?
A
Contraction mechanically pushes blood through the veins
10
Q
How does the increase in venous return lead to an increase in CO?
A
- Increase venous return
- Increased myocardial contractibility (frank starling law)
- Rise in stroke volume
- Rise in cardiac output
11
Q
What can predispose someone to DVT?
A
Long periods of inactivity in sitting position –> slow blood flow –> pooling –> thrombus formation
12
Q
How does blood pressure rise from rest during aerobic exercise vs heavy load exercise?
A
Aerobic –> moderate increase
Heavy load – large increase
13
Q
What is the equation for blood pressure?
A
BP = CO x TPR (total peripheral resistance)
14
Q
What is the exercise pressor reflex?
A
Pressor reflectory response triggered by contracting muscles. Can be triggered by both mechanically and metabolically sensitive muscle afferents.
15
Q
What is the result of the mechanoreflex and metaboreflex within the exercise pressor reflex?
A
Mechano –> immediate rise of Arterial Pressure initiated by muscle deformation or stretch
Metabo –> delayed rise in Arterial Pressure following stimulation of muscle chemoreceptors by metabolites (eg lactate, K+, ATP, H+, prostaglandins)
16
Q
What are the two key baroreflex receptors?
A
Glossopharyngeal nerve and vagus nerve
17
Q
How does an increase in aterial pressure drive the baroreflex?
A
- AP rise
- Glossopharyngeal and vagus signalling
- Brainstem:
- activation of cardiac vagal neurons
- inhibition of cardiac and vascular sympathetic neurons - Increase in cardiac vagal activity and decrease in cardiac and vascular sympathetic activity.
- More vagus = more Acetylcholine release to cardiac sites
Less sympathetic means less NA release to cardiac sites and vascular sites
- HR falls and vasodilation occurs
- CO declines
- AP falls
18
Q
What is the mechanism of the bainbridge (aterial) reflex?
A
- Increase in venus return (increased CVP and aterial pressure)
- Activation of atrial and pulmonary vein stretch receptors
- Signal sent to cardioregulatory and vasomotor centres of the medulla oblongata
- Cardiac vagus signal decreased
- Cardiac sympathetic signal increased - HR increases
19
Q
What are some intrinsic autoregulatory mechanisms in exercising muscle?
A
- Exercise = increase in energy demand + increase in metabolite production
- Reduced pO2
- Decreased ATP
- Increased lactate
- Increased pCO2
- Reduced pH - All these factors result in local vasodilation
20
Q
What is the main factor for autoregulation in coronary blood flow?
A
Hypoxia –> but other factors include CO2 increase and fall in pH
21
Q
What is the mechanism driven by hypoxia in cardiac myocytes?
A
- Hypoxia
- Breakdown of ATP in cardiac myocytes
- Increased adenosine
- Adenosine activates A2 receptors on vascular smooth muscle
- Activation of K(ATP) channels
- Hyperpolarisation
- Smooth muscle relaxation
- Vasodilation
22
Q
What is the equation for minute ventilation?
A
VE (total gas entering the lung per minute = TV (tidal volume = normal volume of air displaced in one breath) x FR (resp rate)
23
Q
How does blood pH and pCO2 affect alveolar ventilation?
A
pCO2 has a much greater increase
24
Q
Why must renal adjustments be made during exercise?
A
Exercising causes a rise in BP and sweating –> without renal compensation this increased fluid loss would lead to dehydration
25
What renal modifications are made during exercise?
- Fall in GFR
| - Increase in NaCl and water reabsorption in kidneys
26
How does the renal system changes during exercise happen?
Reduced GFR:
1. Activation of renal sympathetic nerves and release of adrenaline from adrenals
2. Drives constriction of renal arterioles and afferent arteriols
3. Fall in renal blood flow (up to 25% of normal)
4. Reduces GFR
Preservation of fluids:
1. Release of aldosterone from adrenals and release of ADH from the posterior pituitary
2. Aldosterone = increased NaCl reabsorption
ADH = increased thirst and H2O reabsorption
3. Preservation of fluid and electrolyte levels
27
What thermoregulatory changes are done during exercise and how are they achieved?
1. Increased sweating rate --> sympathetic control
2. Increased cutaneous blood flow --> sympathetic control
Both of these dissipate heat
28
What is the aim of warming up before exercise?
Reduce likelihood of tendon and muscle injury
29
What is the physiological effects both primary and secondary?
Primary --> increase in muscle and core temperature and muscle blood flow
Secondary -->
- Faster muscle contraction/relaxation
- Lower viscous resistance in muscle tissues
- Facilitated O2 delivery
- Facilitate nerve transmission
- Increase muscle metabolism
- Coronary blood supply increases with a lag
30
What effects on the knee joint does collateral ligaments tears have?
Reduces the lateral stability of the joint
31
What effects does an ACL or PCL tear have on the knee joint?
Reduction in antero-posterior stability
32
What is the role of the ACL and how is it damaged?
ACL prevents drawing of tibia against femur anteriorly --> normally damaged with rotational force between tibia and femur
33
What is the role of the PCL and how is it damaged?
PCL prevents anterior displacement of femoral condyles on tibia plateau --> normally damaged by backwards force on tibia while there is forward momentum on femur
34
How to test for ACL and PCL damage?
ACL --> hip at 45 degrees, knee at 90 degrees --> apply explosive anterior force at the joint
PCL --> hip at 45 degrees, knee at 90 degrees --> apply explosive posterior force at the joint
Positive test for both if there is significant movement in the forced direction
35
What are the two common fractures of the femur?
Neck of femur fracture
| Femoral shaft fracture
36
What demographic normally experience femoral neck fractures?
Common in elderly and young high energy
37
Why is one of the main complication of femoral neck fractures avascular necrosis?
Because the head is supplied mainly by the medial and lateral circumflex femoral arteries, which both run up the neck to supply the head. A fracture can interfere with this circulation leading to a cut off of blood and necrosis.
38
What demographic normally experience femoral shaft fractures?
High energy injuries or low energy elderly
39
Is a femoral shaft fracture life threatening? Why?
Yes. Receives large supple of blood. Can cause severe internal haemorrhage
40
What typically causes a patella fracture?
Direct blow to the patella
41
What is some examination findings of patella fracture?
Knee extension failure amount other obvious pain swelling etc
42
What demographics are at risk of knee dislocation (tibiofemoral joint)?
High energy and or high BMI
43
What are the different types of knee dislocation and their corresponding associated injury?
Hyperextension --> PCL tear
Dashboard --> popliteal artery injury
Varus/valgus force --> common peroneal nerve injury
44
What is the tibial plateau?
Flat surface of the distal tibia where the femur articulates
45
What demographics normally see tibial plateau fractures?
Males in 40s (high energy) and women in 70s (low energy)
46
What kind of fractures may be at the tibial plateau?
```
Lateral condyle (outer)
Medial condyle (inner)
Bicondylar (both)
```
47
What conditions may follow a tibial plateau fracture?
Post traumatic arthritis, lateral meniscus tear, ACL tear, compartment syndrome
48
How quickly does compartment syndrome need to be treated?
ASAP --> within 4-6 hours there is muscle and nerve death
49
What does the lateral and medial malleolus refer to?
Lateral --> the inner bone of the ankle joint --> fibula
| Medial --> the outer bone of the ankle joint --> tibia
50
What is the talar bone?
The main articulation point of the ankle joint as it articulates with the tibia
51
What is the common cause of talar neck fracture?
High energy forced dirsiflexion (rising foot towards shin)
52
What is Lis Franc injury?
Where one or more of the metatarsal bones in the foot are displaced from the tarsus (tarsal bones)
53
What is the normal cause of lis franc injury?
High energy activity
54
What is the normal xray finding of lis franc injury?
Widening between 2nd metatarsal and the middle cuneiform --> fleck sign
55
What is the calcaneus?
The heel bone in the foot
56
What is the normal causes for calcaneus fracture?
Axial load or a fall from height
57
What is Trendelenburg sign?
When standing on one leg the hips will angle towards the raised leg
58
What is Trendelenburg sign indicative of?
Gluteal Medius and minimums weakness
59
What is the mission of choosing wisely?
Promoting conversations between clinicians and patients by helping patients choose care that is:
Supported by evidence
Not duplicative testing which has already been done (due to gaps in medical recording systems)
Free from harm
Truly necessary
60
Why is there an international movement about choosing wisely?
To take comorbidities into account with treatment
Not just accepting "textbook medicine"
Assist to reduce variation (eg 12 fold variation in diabetes treatment across Australia)
61
International antimicrobial usage?
Aus 1200 per 1000 people per year
| Canada 650 per 1000 per year
62
Hospitalisation rates of ABTI?
Up to 5 times for chronic disease than other Australians
63
What is the purpose of the Ottawa ankle rules?
To determine the need for an ankle xray series or foot xray series
64
What are the Ottawa ankle rules?
Bone tenderness at the posterior edge or tip of the lateral malleolus
OR
Bone tenderness at the posterior edge or tip of the medial malleolus
OR
An inability to bear weight both immediately and in the emergency department for 4 steps
65
What are the Ottawa rule for foot xray series?
Bone tenderness at the base of the fifth metatarsal (pinky toe side)
OR
Bone tenderness at the navicular (start of the midfoot zone)
OR
An inability to bear weight both immediately and in the emergency department for 4 steps
66
What is Well's scoring used for?
To determine DVT risk score (High, Moderate, low) probability
Score out of 8 --> 3-8 is high
1-2 is moderate
-2-0 is low
67
What are the risks of immobility?
1. Skin degradation
2. Pressure ulcers
3. Muscle weakening
4. Muscular atrophy
5. Disuse osteoporosis
6. Venous stasis
7. Venous insufficiency
8. Orthostatic hypotension
9. etc
68
What are the risks of DVT?
The blood clot can break free and lead to a pulmonary embolism (can be fatal)
69
Coagulation cascade quick summary?
Vascular spasm
Platelet collection --> plug
Fibrin mesh --> strength
70
Types of anticoagulants to use for DVT?
Heparin
| Warfarin
71
How do we treat a pulmonary embolism?
Anticoagulants
Thrombolytics
Surgery
72
```
What is the suspected pathology of:
Bilateral painful lower legs
Hurts to walk and run
Hurts to dorsiflex foot
Tender tibialis anterior region bilaterally
```
ANSWER --> shin splints
| OR --> chronic exertional compartment syndrome
73
What is shin splints?
Shin splints (medial tibial stress syndrome) is an inflammation of the muscles, tendons, and bone tissue around your tibia. Pain typically occurs along the inner border of the tibia, where muscles attach to the bone. Shin splint pain most often occurs on the inside edge of your tibia (shinbone).
74
What is compartment syndrome?
Pressure --> decreases blood flow
| Nerves and tissues --> reduced blood flow leads to pain
75
What determines a certain "compartment" for compartment syndrome?
Fascia Lata
76
What is the surgical treatment for compartment syndrome?
Fasciectomy
77
What is the probable nerve cause of someone presenting with:
Unable to dorsiflex foot
Numbness over dorsum extending laterally up the lower leg
probably superficial fibular nerve
78
What is a good mnemonic for the types of fractures?
(dividing the word SALTER) from salter harris fractures.
I – S = Slip (separated or straight across). Fracture of the cartilage of the physis (growth plate)
II – A = Above. The fracture lies above the physis, or Away from the joint.
III – L = Lower. The fracture is below the physis in the epiphysis.
IV – TE = Through Everything. The fracture is through the metaphysis, physis, and epiphysis.
V – R = Rammed (crushed). The physis has been crushed.
79
What is the main blood supply to the femoral head?
Inferior gluteal artery
80
What can cause heel pain on walking?
Calcaneal apophysitis
81
What kind of joint is the hip joint and what three bones forms it?
Ball-and-socket
| Formed by the ilium, ischium and the pubis
82
What does a history of fall and inability to walk or bear weight on the leg suggest?
Suggests a fracture in the neck of the femur
83
What do you want to watch of a patient for a lower limb examination?
How they walk:
1. Use of support (walking stick, walker etc)
2. Speed
3. Obvious uncomfortable gait or limp
84
How should you move the hip joint in examination?
1. Flexion (knee bent) --> patients on back --> thigh into patients chest
2. Flexion --> patient on back --> leg straight --> move leg up towards chest
3. Extension --> lying on front leg straight and bending backwards into the air
4. Rotation (internal) --> patient on back --> knee turns inwards
Rotation (external) --> patient on back --> knee turned outwards
85
What is the medial swipe in a knee examination?
1. Empty the fluid from the medial aspect of the knee into the suprapatellar pouch
2. Hold fluid there by keeping hand in place
3. Swipe down from the suprapatellar pouch on the lateral side
4. If a bulge or ripple appears on the medial side it indicates effusion
86
What kind of hip tests are FABER and FADIR?
Hip provocation tests
87
What direction does the foot go when testing hip for external rotation?
Foot goes medially
88
What is the FABER test?
```
Assesses
F -lextion
AB -duction
E -xternal R- otation
Of the hip
```
89
What is the FADIR test?
Flex Adduction internal rotation
90
What is Trendelenburg test?
The patient stands first on one leg and then on the other. Normally the non-weight-bearing hip rises, but with proximal myopathy or hip joint disease the non-weight-bearing side sags.
91
How is the petellar tap done?
Pushing down inferiorly to the patella pouch and holding fluid there
The other hand is then used to tap the patella to measure movement of the patella
92
What are the potential movements of the hip?
```
Flexion
Extension
Flexion (knee bent)
Internal rotation (knee facing in)
External rotation (knee facing out)
Abduction
Adduction
```
93
What are the movements of the knee?
Extension
Flexion
Lateral rotation
Medial rotation
94
What are the movements allowed by the ankle joint?
Plantarflexion
| Dorsiflexion
95
What joint allows for inversion and eversion at the ankle/foot?
Subtalar joint
96
How does inversion and eversion of the foot appear?
Inversion --> foot moved medially --> big toe up
Eversion --> foot moved laterally --> pinky toes up
97
What is the patellar tap used for?
To detect large effusion
98
Important pulses in the lower limb?
Femoral
Popliteal
Dorsalis pedis
Anterior and posterior tibial artery
99
What is pitting oedema vs swelling?
Pitting is fluid build up --> depressing skin with finger
100
What are some Gait types?
Antagic
Trendelburg
Fixed flexion
101
What is the difference between cruciate and collateral ligaments?
Cruciate = centre (crossed over like crucifix)
Collateral = lateral
102
What is the Lachman test for?
Identify integrity of the anterior cruciate ligament (most sensitive examination)
103
What is Lachman's test?
Flex the leg to 30 degrees
Hold the lower leg with one hand
Hold the thigh with the other hand
Use the hand holding the lower leg to pull the tibia forward on the femur while the other hand stabilises the femur
104
What is the anterior and posterior drawer test for the knee?
1. Patients knee is at a 90 degree angle with foot flat on bed and hip at 45 degree angle
2. Explosive posterior force or anterior force (2 tests) is applied
3. Excessive movement suggests anterior/posterior cruciate ligament laxity or rupture
105
What is the test for collateral ligaments?
Lateral collateral ligament (LCL):
Below are instructions to examine the right knee – change your hands for the left knee
1. Extend the patient’s knee fully.
2. Hold the patient’s ankle between your elbow and side.
3. Place your right hand along the medial aspect of the knee.
4. Place your left hand on the lower limb (e.g. calf or ankle).
5. Push steadily outward with your right hand whilst applying an opposite force with the left.
6. If the LCL is damaged your hand should detect the lateral aspect of the joint opening up.
Medial collateral ligament (MCL):
Below are instructions to examine the right knee – change your hands for the left knee
1. Extend the patient’s knee fully.
2. Hold the patient’s ankle between your elbow and side.
3. Place your right hand along the lateral aspect of the knee.
4. Place your left hand on the lower limb (e.g. calf or ankle).
5. Push steadily inward with your right hand whilst applying an opposite force with the left.
6. If the MCL is damaged your hand should detect the medial aspect of the joint opening up.
106
Role of the ACL?
The ACL (anterior cruciate ligament) prevents anterior (forward) movement of the tibia off of the femur, as well as hyperextension of the knee (a straightening movement that goes beyond the normal range of motion in the joint)
107
Role of the PCL?
to prevent the femur from sliding off the anterior edge of the tibia and to prevent the tibia from displacing posterior to the femur.
108
Role of the collateral ligaments?
tibial (medial): capsular, between medial femoral and tibial condyles
MCL provides valgus stability to knee, primary knee stabiliser, prevents hyperextension of joint fibular
(lateral): extra-capsular, between femoral condyle and fibula head
LCL avoids varus stress across knee (knee buckling outwards)
109
Role of the meniscus?
The menisci act to disperse the weight of the body and reduce friction during movement. Since the condyles of the femur and tibia meet at one point (which changes during flexion and extension), the menisci spread the load of the body's weight.
110
Role of the bursa?
A bursa is a sac containing a small amount of synovial fluid that lies between a tendon and either skin or bone to act as a friction buffer. There are more than 150 bursae in the body and they can either be deep or superficial. There are may bursae present around the knee joint (suprepatella, subcutaneous prepatellar, depp infrapatellar, subcutaneous infrapatellar
111
Role of the patella tendon?
Connects patella to tibial tuberosity. Acts as a "lever" and therefore allows quadriceps femoris to exert a higher moment around the axis of rotation of the knee for a given level of muscle contraction than in the absence of a patella. This ensures that knee extension is more efficient, and the action of quadriceps femoris is clearly transmitted through to the tibia.
112
What are tendons composed of?
dense fibrous connective tissue made up primarily of collagenous fibres
113
What are ligaments composed of?
a band of dense regular connective tissue bundles made of collagenous fibres, with bundles protected by dense irregular connective tissue sheaths
114
What is the meniscus of the knee composed of?
The menisci of the knee are two pads of fibrocartilaginous tissue on the articulating condyles of the tibia
115
In two different swollen legs, one with fast and the other with slower swelling. Which one was from haemarthrosis and which one is inflammatory factors and inflammation?
Haemarthrosis is faster
116
What is the structure of the labrum?
Fibrocartilage
117
How many tibio fibular joints are there?
3
Proximal
Distal
Interosseus or syndesmosis?
118
What kind of bone is the patella?
Sesamoid
119
Large nerves in the lower limb?
Tibial
Femoral
Popliteal/Fibular (circles fibular neck)
120
How to measure true leg length?
measurement taken from the anterior superior iliac spine to the tip of medial malleolus while both lower limbs are in identical positions and the pelvis is square.
121
Is different length of limbs normal?
Yes
122
When is leg length difference a concern?
More than 4cm
123
How many tarsal bones are there?
```
7
Calcaneus
Talus
Cuboid
Navicular
Cuneiform x 3
```
