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Flashcards in Osteoporosis Deck (54)
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1
Q

What is Parathyroid hormone (PTH)?

A

Polypeptide hormone produced by parathyroid glands

2
Q

When is PTH released?

A

Released in response to decrease in free [Ca2+] plasma - Picked up by calcium-sensing receptors (CaSR) located on parathyroid (chief) cells.

3
Q

What are the actions of PTH?

A

Acts to increase [Ca2+] by:

  1. Stimulating osteoclasts - 12-24hr effect
  2. Inhibit osteoblasts
  3. Decrease Ca2+ excretion at the kidneys
  4. Increasing renal excretion of phosphate
  5. Stimulates calcitriol synthesis - kidneys from vitamin D3
4
Q

What is Calcitriol?

A

A steroid hormone produced by the kidneys and liver which complements the activity of PTH

5
Q

How is Calcitriol synthesised?

A
6
Q

What are the actions of Calcitriol?

A

Binds nuclear receptors in target tissue (intestine, bone, kidney):

  • Increases absorption of Ca2+ from the gut
  • Facilitates renal reabsorption of Ca2+
  • Mobilises calcium stores in bone by stimulating osteoclast activity
7
Q

What are the dietary sources of Vitamin D3?

A
  • Fatty fish - mackerel and tuna
  • Fish liver oils
  • Egg yolks
8
Q

What is the definition of Osteoporosis?

A

“Normal bone, not enough of it”

  • A condition of skeletal fragility characterized by reduced bone mass and microarchitectural deterioration
  • A result on DXA bone scanning <2.5 SDs below the young adult mean
9
Q

How does Osteoporosis occur? (i.e. what is the pathogenesis?)

A

Bone mass decreases with age, but will depend on

  • Peak bone mass - attained in adult life
  • Rate of loss - in later life.

Mechanisms involved include:

  • Failure to achieve adequate peak bone mass
  • Increase in bone resorption
  • Reduction in bone formation.
10
Q

What are the causes of osteoporosis?

A

SHATTERED Family

  • Steroid use
  • Hyperthyroidism; hyperparathyroidism, hypercalciuria
  • Alcohol and tobacco use
  • Thin (BMI <22) - Anorexia nervosa
  • Testosterone low (e.g. anti androgen in cancer of prostate)
  • Early/post-menopause
  • Renal or liver failure
  • Erosive/inflammatory bone disease - RA, multiple myeloma, osteogenesis imperfecta
  • Dietary Ca low/malabsorption or Diabetes mellitus type 1
  • Family history
11
Q

What are the Risk Factors of Osteoporosis which you would want to ask someone about?

A
  • Smoking
  • Alcohol
  • Menopausal status
  • Immobility/exercise
  • Diseases which influence bone turnover - thyrotoxicosis, malabsorption, inflammatory arthritis
  • Medications - steroid use
12
Q

How does someone with osteoporosis present?

A
  • MAINLY ASYMPTOMATIC - picked up incidentally or ini context of fragility fracture
  • Fragility fractures
  • Pain - from mechanical derangement
  • Thoracic Kyphosis
  • Height loss
  • Features of underlying cause - e.g. signs of endocrine disorder such as cushings syndrome
13
Q

What are the different types of fragility fractures seen in Osteoporosis?

A

THESE ARE RED FLAG FRACTURES FOR OSTEOPOROSIS

  • Vertebral crush fractures
  • Colle’s Fracture
  • Fractures of proximal femur (#NOF)
  • Shoulder Fracture
  • Pubic Ramus Fracture
14
Q

What is the differential diagnosis for fragility fractures?

A
  • Osteoporosis
  • Osteomalacia
  • Paget’s disease
  • Tumour - primary or metastatic
  • Osteogeneis Imperfecta
15
Q

What are vertebral crush fractures?

A

“Dowagers hump

These are the most common fractures in osteoporosis - Wedge fracture of spinal vertebrae, which lead to kyphotic deformity

Fractures are mostly thoracic, can be lumbar, and are rarely cervical

Outcomes of the fracture include chronic pain (nerve entrapment), reduced QOL, decreased mobility and reduced chest compliance (FVC decreases 9% per vertebrae fractured).

16
Q

What is a Colle’s Fracture?

A

Colles fractures are very common extra-articular fractures of the distal radius that occur as the result of a fall onto an outstretched hand (FOOSH)

17
Q

What are the complications of a Colle’s Fracture?

A

Occurs in 20% of patients

  • Malunion - dorsal angulation, radial deviation & shortening
  • Stiffness - many #’s are intra-articular
  • Median nerve entrapment - Carpal Tunnel Syndrome
  • CRPS type 1
  • Rupture of tendon of EPL - late complication due to impaired blood supply
18
Q

What are the different types of hip fracture?

A

Can be NOF or proximal femoral fracture

Types include

  1. Intracapsular (50%)
  • Displaced
  • Undisplaced
  1. Extracapsular (50%)
  • Basal cervical
  • Subtrochanteric
  • Intertrochanteric - 2 part comminuted
19
Q

What are some of the complications of an Osteoporotic shoulder fracture?

A
  • Axillary nerve palsy
  • Malunion
  • Stiffness
20
Q

What clinical picture would indicate a possible Pubic ramus fracture?

A
  • HISTORY OF A FALL
  • Elderly (very)
  • Female patient
  • Unable to walk
  • Pain & tenderness in groin and on leg movement
21
Q

How would you treat a Pubic Ramus Fracture?

A
  • Short period of bed rest (48h), then mobilise (with physiotherapy)
22
Q

What imaging would you do to assess for a potential diagnosis of osteoporosis?

A
  • X-Ray
  • DEXA Bone scan
23
Q

How would you determine who should be treated?

A
24
Q

Concerning the management of someone with Osteoporosis, what lifestyle advice yould you give them?

A
  • Smoking cessation
  • Alcohol cessation
  • Weight bearing exercise
  • Balance exercises
  • Home based fall prevention programme
25
Q

Concerning the management of somone with Osteoporosis, what pharmacological interventions are available?

A
  • Calcium and Vitamin D supplementation
  • Hormone Replacement Therapy (HRT)
  • Selective oestrogen receptor modulators (SERMs)
  • Bisphosphonates
  • Strontium Renelate
  • Recombinant HPTH (teriparatide)
  • Denosumab
26
Q

Concerning the management of someone with Osteoporosis, what are the factors which determine the pharamacological approach used?

A
  • Age
  • Number of risk factors
  • Bone mineral density
27
Q

What can stimulate the release of calcitriol in women?

A

Prolactin - in response to Ca2+ loss through lactation

28
Q

How does calcitriol increase Ca2+ absorption from the gut?

A

Ca2+ absorbed via active transport from intestinal lumen

  • Decreased [Ca2+] → increase PTH → increases Calcitriol → increases intestinal absorption
  • Increased [Ca2+] → inhibit PTH → less resorption and more deposition in bone
29
Q

What factors influence peak bone mass?

A
  • Genetic
  • Nutritional - e.g. alcohol greater than 4 units/day
  • Exercise
  • Disease processes
  • Drugs - such as Corticosteroids.
30
Q

What factors influence age related bone loss?

A
  • Loss of sex hormones - untreated menopause
  • Genetic
  • Nutritional
  • Exercise
  • Drugs - Corticosteroids and aromatase inhibitors.
31
Q

What medications can cause osteoporosis?

A
  • Steroids
  • Aromatase inhibitors
  • Warfarin
  • TCA
  • Diabetic meds
  • Anticonvulsants
32
Q

Can you name the classic deformity of a Colle’s Fracture, and the 5 components of this deformity?

A

Classic Deformity - DINNER FORK DEFORMITY

  • Dorsal Angulation + Displacement
  • Radial Shortening + Deviation
  • Supination
33
Q

What can be seen on this X-ray of the wrist of a 65 year old women after a fall onto an oustretched hand?

A

Colle’s Fracture

34
Q

What blood investigations could you do if investigating for a potential diagnosis of osteoporosis?

A

Main Bloods

  • Ca2+
  • PO43-
  • Alkaline phosphatase - should be normal

Other bloods

  • 25-Hydroxyvitamin D and PTH
  • Renal function
  • TFT and LFTs
  • Multiple myeloma screen - ESR, serum IG, protein electrophoresis, urinary Bence Jones protein
  • Consider coeliac screen, urinary cortisol, testosterone, oestradiol, LH + FSH prolactin
35
Q

When are bisphosphonates used?

A

Potent antiresorptive agent

  • Corticosteroid induced osteoporosis
  • Prevention and treatment of postmenopausal osteoporosis
  • Osteoporosis in men
36
Q

What are the side effects of bisphosphonates?

A
  • GI disturbance
  • Gastric and oesophageal ulceration
  • Iritis/uveitis
  • Renal toxicity
  • Atypical femoral shaft fracture
37
Q

What does Denosumab act against?

A

RANKL - reduces osteoclast activity, which reduces bone breakdown

38
Q

What is a DEXA Bone Scan?

A

Looks at bone mineral density at the lumbar spine (L1-L4) and proximal femur

T-score of less than −2.5 indicates osteoporosis

T score of between −1.0 and −2.5 indicates osteopenia

39
Q

What is an intracapsular hip fracture?

A

Fracture of neck of femur inside the hip capsule

40
Q

What is an extracapsular hip fracture?

A

Between insertion of hip joint capsule and 5cm below lesser trochanter

41
Q

What are the different types of intracapsular hip fractures?

A
  • Basal cervical
  • Transcervical
  • Subcapital
42
Q

What are the different types of extracapsular hip fractures?

A
  • Intertrochanteric
  • Reverse oblique
  • Subtrochanteric
43
Q

What are clinical features of a hip fracture?

A
  • Fall followed by pain in the groin with referred pain to the thigh
  • Limited ability to weight bear
  • Limited ROM
  • Externally rotated and shortened limb - displaced fracture
44
Q

What type of fractures often cause shortened, adducted, externally rotated legs?

A

Intracapsular fracture - displaced

45
Q

What type of fractures of the hip have increased risk of AVN?

A

Intracapsular - can be 80% risk if fracture is displaced

46
Q

What is the following type of fracture?

A

Intracapsular fracture

47
Q

What is the classificaiton system used for intracapsular hip fractures?

A

Garden classification

48
Q

What is shenton’s line?

A

Shenton line is an imaginary curved line drawn along the inferior border of the superior pubic ramus (superior border of the obturator foramen) and along the inferomedial border of the neck of femur.

49
Q

How would you manage a displaced intracapsular fracture of the neck of femur?

A
  • Analgesia
  • Surgical Hemiarthroplasty/THR
50
Q

How would you manage a non-displaced intracapsular fracture?

A
  • Analgesia
  • Internal fixation - cannulated hip screw
51
Q

If you suspected a hip fracture, what investigations might you consider doing?

A
  • Bloods - FBC, U+E’s, LFTs, Coag, G+S
  • Imaging - AP and lateral radiograph
52
Q

How would you manage an basicervical/intertrochanteric fracutre?

A
  • Analgesia
  • Fluids
  • Surgical fixation - dynamic hip screw
53
Q

How would you manage a subtrochanteric/Transtrochanteric hip fracture?

A
  • Analgesia
  • Fluids
  • Surgical fixation - intramedullary nail
54
Q

Where do osteoporotic vetebral crush fractures ususally occur?

A

Usually occur around the mid-thoracic level (T7-T8) or thoracolumbar junction level (T12-L1) - anything above T7-T8 may be thought of as another cause e.g spinal mets