Case 1 - lower limb (knee) Flashcards

0
Q

List the cartilages of the knee joint and their function

A

Articular cartilage

Medial meniscus
Lateral meniscus
- the menisci act as shock absorbers and deepen the articular surface of tibia thus increasing stability
- made up of fibrocartilage and attach onto the inter condylar area of tibia

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1
Q

What type of joint is the knee joint, name the 3 articulations.

A
  • synovial hinge
  • articulations
    1) femoropatellar a between patella and femur
    2) femorotibial - between lateral condyles of tibia and femur
    3) femorotibial - between medial condyles of tibia and femur
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2
Q

Name the bursae and state their clinical relevance

A

You have supra patella, prepatellar and semi membranous bursae as well as others.
Bursae are lined with synovium which contains synovial fluid.
With increased irritation more fluid accumulates leading to significant swelling. This getting bursitis.
(Prepatellar “ housemaid’ knee “ or supra patellar)

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3
Q

List the ligaments of the knee

A

Extracapsular ligaments

  • Patellar ligament
  • fibular collateral ligament
  • tibial collateral ligament

Intra capsular ligament

  • anterior cruciate ligament (attached to anterior inter condylar region)
  • posterior cruciate ligament (attached to posterior inter condylar region)
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4
Q

Explain how bone healing occurs

A

1- Inflammation - soon after fracture occurs large amounts of bleeding occurs, causing swelling and bruising known as “haematoma”
Macrophages and leukocytes move in and scavenge debris.. They begin to produce pro-inflammatory debris which initiates healing
2- Soft callus -
inflammation triggers cell division and growth of new blood vessels.
Collagen is secreted by chondrocytes, which creates fibrocartilage forming soft callus
3- hard callus - endochondral ossification, woven bone replaces soft callus with hard callus around broken bone fragments
4- remodelling - strong and highly organised cortical bone replaces weaker disorganised woven bone.

** bone is the only tissue to heal without a scar - as continually remodelled

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5
Q

What are the common injuries for each of these structures? Does tissue regeneration restore mechanical properties, how long is the healing time?

A

McajHjfrnnfkslf,SDD import image on computer

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6
Q

What factors affects the healing process?

A

Age - children healing better than adults
Nutrition
Systemic diseases
Hormones - in menopausal women, lack of oestrogen affects osteoporosis healing
Degree of trauma
Infection

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7
Q

Name the borders and contents of the femoral triangle. Femoral hernias can occur from the abdomens to the femoral canal, why is this more common in women?

A

Borders:
Lateral- sartorius
Superior - Inguinal ligament
Medial- adductor longus

Contents
Lateral to medial ; (NAVY) femoral nerve, artery, vein

Femoral hernia
Abdominal contents up to femoral canal where lymphatic system usually are
More likely in women as their pelvis is wider

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8
Q

List the main features of the tibia, femur and fibular

A

See page 303, Mcminn’s atlas of anatomy

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9
Q

Name the veins of the lower limb. You have deep veins and superficial.

A

Add picture

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10
Q

Name the arteries of the lower limb

A

Add picture

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11
Q

Tendons.
What is their function?
what are the two different types?
list some features.

A
  • Flexor tendons: round or oval allow gliding
  • Extensor tendons: flat, allow rolling across convex surface

Functions;

1) increased efficiency of movement - keeps muscle belly away from site of action
2) Tendon elasticity allow them to act as springs, this prevents muscle fatigue
3) reinforces and replaces capsules e.g. At glenohumeral joint
4) passes through small spaces

Features;

  • Made up of DENSE FIBROUS REGULAR CONNECTIVE TISSUE
  • Type 1 collagen
  • Visco-elastic slower stretch means more stretch
  • Dynamic structure - more extra cellular matrix is produce in response to increased mechanical loading
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12
Q

Ligaments.
What is their function?
Also list some features.

A

Function;
Stabilise joint and guide movement
Hold tendons in place
Proprioception (mechanoreceptors found at knee, shoulder, ankle joints)

Features;

  • Made up of DENSE FIBROUS REGULAR CONNECTIVE TISSUE
  • Type 1 collagen
  • Visco-elastic slower stretch means more stretch
  • Dynamic structure - more extra cellular matrix is produce in response to increased mechanical loading
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13
Q

What one of these causes tendons to be more prone to pathology?

A - Age (more prone when younger)
B - Gender
C - Age (more prone when older)
D - Ethnicity

A

C - Age (more prone when older)

With age, less force is required to elongate tendon making it weaker.

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14
Q

A 67 year old lady has come into clinic suspecting there is something wrong with extending and flexing her legs, although not feeling any pain. The doctor does a test which proves that she has a ruptured Achilles’ tendon. What did the doctor do and what sign did the patient show?

A - negative Barbinski 
B - positive Smith test 
C- negative Thompson test 
D - positive Thompson test 
E - Thompson test
A

D - positive Thompson test

Doctor squeezed the calf muscles (gastrocnemius, soleus), and the Achilles’ tendon should plantar flex the foot. If there is no movement of the ankle, then this shows the tendon is ruptured = Positive Thompson test

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15
Q

Name the three specialised regions related to tendons and ligaments

A
  • Myotendinous region
  • Enthesis
  • Wrap- around regions

Remember WEM!

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16
Q

What is Myotendinous junction?
Location?
Features?

A
  • located at muscle- tendon interfaces
  • important for transmitting muscle contractions to the tendon

** you can get muscle tears at this MT junction

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17
Q

What is an Enthesis?

Location?

A

Sites of insertion of tendons or ligaments onto bone

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18
Q

Features of Enthesis?

A

Features;
Two types

1) fibrous 
Where tendon or ligament inserts directly onto bone 
2) fibrocartilaginous 
Where you  get 4 types of tissue 
- pure dense connective tissue
- uncalcified fibrocartilage
- calcified fibrocartilage 
- bone
19
Q

What are wrap around regions and why have tendons got this adaptation?

A

Gliding regions where tendons change direction as they wrap around bony pulleys.
Fibrocartilage is common here, it is an adaptation to resisting compression

20
Q

Pathologies of tendons?

A

See case 1 microanatomy of tendons and ligaments notes

21
Q

Inflammation: what are the cellular mediators of acute inflammation?

A

Histamine - released by mast cells causing vasodilation and increased vascular permeability

Cytokines - released by macrophages

22
Q

Name some cytokines involved in inflammatory response

A

TNF-1 and IL-1

They cause a local and systemic effect

23
Q

Name the plasma derived mediators

A

Compliment proteins and kinins

24
Q

Cytokines are released by macrophages during inflammatory response?, what effect does this have?

A increases vascular permeability
B promotes immigration of WBCs and promotes fibroblast proliferation
C vasodilation
D diapedesis

A

The answer is B, cytokines cause leukocytes in blood vessel to adhere to endothelial lining by integrins. Thus cytokines promote leukocyte immigration, and stimulate fibroblasts to proliferate.p (increasing collagen synthesis for repair)

25
Q

What are the roles of C3a and C5a in the response after an injury to the knee?

A

These are compliment proteins that are

  • chemoattractants
  • increase vascular permeability
26
Q

What are the plasma derived mediators?

A

Compliment proteins

Kinins

27
Q

Apart from cytokines produced de novo my macrophages and endothelial cells, what other mediators are produced by WBcs?

A

Arachadonic acid metabolites

  • prostaglandins; cause fever and pain
  • leukotrienes; chemoattractants and increase vascular permeability
28
Q

What is the difference between acute and chronic inflammation (other than the obvious)

A

Main cell;

  • acute = neutrophils
  • chronic = macrophages

Tissue injury;

  • acute = mild
  • chronic = severe
29
Q

What causes chronic inflammation?

A

1) persistent infection
2) prolonged exposure to toxic agents endog. Or exog.
3) autoimmunity

30
Q

What do monocytes become once they enter the tissue from the blood?

A

Macrophages

31
Q
These are the characteristics of inflammation? What is the cause of the following; 
Rubor 
Tumor
Calor
Dolor 
Function laesa
A

Rubor. Redness. Caused by increased blood flow
Calor. Heat. Caused by increased blood flow

Dolor. Pain. Prostaglandins
Tumor. Swelling. Leakage of plasma proteins and fluid into the tissue

32
Q

What are the features of systemic inflammatory syndrome?

A
  1. Fever and Leukocytosis - more wbcs circulating in blood
  2. Increasee pulse rate, blood pressure and decreased swelling, rigors malaise
  3. Sepsis: severe bacterial infections
33
Q

What is pain?

A

Pain is the unpleasant sensory experience associated with nociception

34
Q

What is nociception?

A

The perception of tissue damage

35
Q

What are the different kinds of pain?

A

Carry some neon red vase

Cutaneous

Somatic - damage to muscle or ligaments (maybe due to trauma)

Neuropathic - nerve damage

Referred - pain from organs but appears to be cutaneous

Visceral - from visceral organs, have iwn ascending pathway

36
Q

What are the characteristics of the three different nociceptors?

A

A delta fibres - thinly myelinated

C fibres are - non myelinated

A beta fibres - more myelinated than A delta (fastest transmission out of the three)

37
Q

What do the three nociceptors each sensitise?

A

A delta fibres - mechanical change e.g. Cutting

C fibres (polymodal nociceptor) - irritant chemicals

A beta fibres - non-noxious stimuli e.g. Touch, light

38
Q

What is allydonia?

A

Pain due to a stimulus that doesn’t usually provoke pain

39
Q

What is gate theory

A

Useful way of thinking about pain experience.

  • entry if impulses is monitored by substantia gelatinosa
  • Ad and c fibres stimulate and open gate
  • AB fibres counter stimulate and close gate. Cant have touch and pain stimulation entirely at the same time
40
Q

When does pain become chronic?

A

When pain interferes with life activities

41
Q

How do you measure pain?

A

1) verbal report
2) pain questionnaires
3) visual analogue?

42
Q

How do prostaglandins relate to pain?

A

See notes

43
Q

NSAIDS mechanism of action?

A

NSAIDs inhibits the Cyclo-oxygenase domain of prostaglandin-H synthase. Thus the synthesis of PGH2 and PGG2 is inhibited.

44
Q

Why is asprin not given to children under the age of 16?

A

It is strongly linked to Reyes syndrome