Case 1 - wrap up Flashcards
how does medial collateral ligament damage usually result from?
Usually results from a varus force across the knee
So force is from the lateral side displacing the knee towards the midline
(medially)
where is medial collateral ligament damage common in?
MCL injuries are common in sports (also in farmers being kicked or
squished by cows)
how does medial collateral ligament damage cause pain
They cause Medial knee pain, often patients can walk, most common knee ligament injury
[medial collateral ligament damage can be associated with cruciate and meniscal injuries so need this assessing]
valgus producing force on the lateral side of the knee causes what?
causes a torn medial collateral ligament
valgus producing force on the medial side of the knee causes what?
causes a torn lateral collateral ligament
Diagnosing Ligament Knee Damage
- History – nature of the trauma
- Immediately after injury can be difficult
- Look for gross effusion and bony abnormalities
- No bony trauma
- Immediate effusion
Assess ROM - range of motion
* Look for extent of extension/flexion – ACL/PCL injury?
* Apply Valgus/Varus stress at 30o of flexion – indicates amount of
Lateral/Medial CL opening
Osseous tissue components - there are 4 main types of bone cells, which are
osteogenic cells
osteoblasts
osteocytes
osteoclasts
what are osteogenic cells
they are stem cells found in the endosteum, periosteum and in the central canals
they give rise to most other bone cells
osteogenic cells arise from the embryonic mesenchymal tissue
the events in the repair of a bone fracture
formation of a fracture hematoma.
formation of an internal and an external callus.
replacement of the cartilage of the external callus with bone.
remodelling overtime and completion of repair.
nociception refers to what? and pain refers to what?
nociception refers to neural encoding of impending or actual tissue damage
(i.e., noxious stimulation), pain refers to the subjective experience of actual or
impending harm
keratinocytes absorb what to make vitamin D3?
keratinocytes absorb UVB to make vitamin D3.
[so we want some UV radiation reaching our skin but shade can be sufficient in this. Also, UVR causes photolysis of folic acid, and so depletes folic acid stores]
process of coagulation - starting with injury
1) Injury - a blood vessel is severed. blood and blood components are leaking out of breaks
2) vascular spasm - the smooth muscle in the vessel wall contracts near the injury point, reducing blood loss
3) platelet plug formation - platelets are activated by chemicals released from the injury site and by contact with the underlying collagen. the platelets become spiked and stick to each other and the wound site
4) coagulation - here fibrinogen is converted to fibrin, which forms a mesh that traps more platelets and erythrocytes, producing a clot
what about the coagulation pathways?
intrinsic pathway:
damaged vessel wall used in conversion of factor XII → factor XIIa
factor XIIa used in conversion of factor XI → factor XIa
factor XIa used in conversion of factor IX → factor IXa
factor IXa used to make a complex of factor IXa with factor VIIIa
the factor IXa and VIIIa complex is used in conversion of factor X → factor Xa
extrinsic pathway:
trauma to extravascular cells creates factor III
factor III used in conversion of factor VII → factor VIIa
factor VIIa used to make a complex of factor VIIa and factor III
the factor VIIa and factor III complex is used in conversion of factor X → factor Xa
factor Xa is where the intrinsic and extrinsic pathways converge
final common pathway:
factor Xa, using factor Va coverts Prothrombin (III) → thrombin (IIIa)
thrombin (IIIa) used in conversion of Fibrinogen (I) → Fibrin (Ia)
Fibrin (Ia), using factor XIIIa, makes cross-linked fibrin clot
An 18 year old woman attends her GP practice with frequent, unexplained bruising on her back, arms and legs. Blood tests reveal a low platelet count.
What blood disorders does she have?
Thrombocytopenia
Thrombocytopenia is characterised by?
Thrombocytopenia is characterised by a low platelet count, which impairs the blood’s ability to form clots.
[Symptoms of thrombocytopenia are:
*easy bruising.
*abnormal bleeding (nosebleeds, bleeding gums, heavy heavy periods)
*blood in your poo or urine (wee)
*pinpoint bleeding in your skin that looks like a purplish-red rash (known as petechiae)
*cuts that keep bleeding]
conduction speeds of pain nerve fibres from slowest to fastest
slowest to fastest:
C fibres (slowest)
A-delta
A-beta
A-alpha (fastest)
information carried in each type of pain nerve fibre?
A-alpha fibres: proprioception
A-beta fibres: touch
A-delta fibres: pain (mechanical and thermal)
C fibres: pain (mechanical, thermal and chemical)
myelin sheaths on which pain nerve fibres?
A-alpha, A-beta, A-delta nerve fibres are all myelinated
C fibres are non-myelinated
from smallest to largest pain nerve fibres?
smallest to largest:
C fibres (smallest)
A-delta
A-beta
A-alpha (largest)
A 32-year-old gentleman comes to the emergency unit after being involved in a sports injury. His foot is dorsiflexed and everted.
Which nerve is not functioning properly?
A. Common fibular
B. Deep common fibular
C. Femoral
D. Tibial
D. Tibial
When checking arterial blood is flowing to the lower limb, you will palpate behind the medial malleolus.
What blood vessel are you palpating?
A. Anterior tibial artery
B. Dorsalis pedis artery
C. Fibular artery
D. Popliteal artery
E. Posterior tibial artery
E. Posterior tibial artery
A patient, who is a research scientist in leukaemia, asks you how the large metastatic cancerous growth is being sustained (he has
just been diagnosed with it).
What is the most likely chemical mediator causing the
physiological accommodation?
A. IL-2
B. IL-6
C. IL-10
D. TNFa
E. VEGF
E. VEGF
A neonate presents with abnormal haemostasis. There is
increased time between activation of the intrinsic pathway
and fibrin formation as well as decreased FVII coagulant
activity.
Which haemorrhagic condition is present?
A. Haemophilia A
B. Haemophilia B
C. Haemophilia C
D. Vitamin K deficiency
E. von Willebrand disease
D. Vitamin K deficiency
A 45 year-old lady attends a routine nurses appointment with
green bruising on her face.
What, most likely, does the colour inform you of?
A. The bruise is 5-10 days old
B. The bruise is 10-15 days old
C. The patient is deficient in Vit C
D. The patient is deficient in Vit K
E. The patient received trauma
E. The patient received trauma
