Rheumatology (Diseases of Bone and Connective tissue disorders Flashcards

1
Q

osteoporosis

A

reduced bone density leading to fragile bones more susceptible to fracutes

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2
Q

risk factors for osteoporosis

A

Primary
- age
- female (menopausal)
- low BMI
- corticosteroid therapy
- cushings syndrome
- alcohol
- smoking

Secondary
- hyperthryoidims
- primary hyperparathyroidism
- CKD
- Crohns, UC, coeliac
- RA

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3
Q

presentation of osteoporosis

A

asymptomatic usually prior to fragility fracture

common sites of fractures
- Vertebral compression fractures
- Neck of femur fractures
- Colles fracture

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4
Q

which tool is used to predict 10-year risk of fracture

A

FRAX tool
- if score high enough patient is sent for DEXA scan

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5
Q

Who should have their FRAX calculated

A
  • Anyone on long-term oral corticosteroids or with a previous fragility fracture
  • Anyone 50 and over with risk factors
  • All women 65 and over
  • All men 75 and over
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6
Q

who should have a DEXA scan

A
  • Those with a high enough FRAX tool according to NOGG guidelines
  • A DEXA may be arranged without calculating the risk in patients over 50 with a fragility fracture
  • Treatment may be started without a DEXA in patients with a vertebral fracture
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7
Q

dual-energy x-ray absorptiometry (DEXA) scan

A

This measures BMD which is then given a T-score.
This is a score based on the BMD of a young reference population

  • > -1.0 is normal
  • -1.0 to -2.5 indicates osteopenia
  • <-2.5 is classed as osteoporosis
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8
Q

further investigations to determine cause of osteoporosis

A

The next investigations are to identify or rule out any possible secondary causes:

  • X-ray of the wrist, heel, spine, and hip
  • CT if DEXA is not available
  • Bone profile – calcium, phosphate, albumin, and ALP
  • Serum PTH
  • Serum 25-hydroxyvitamin D
  • TFTs
  • U&Es
  • Serum testosterone (considered in all men with osteoporosis)
  • Urine and serum protein electrophoresis
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9
Q

conservative management of osteoporosis/osteopenia

A

The first step is to address reversible risk factors.

  • Increase physical activity
  • Maintain a healthy weight
  • Stop smoking
  • Reduce alcohol consumption.
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10
Q

who requires pharmacological management of osteoporosis

A
  • A FRAX 10-year probability of osteoporotic fracture >1%
  • A hip or vertebral fracture
  • T-score <-2.5
  • T-score between -1.0 and -2.5 and a FRAX 10-year probability of osteoporotic fracture >3%
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11
Q

pharmacological management of osteoporosis

A

First line:
- Bisphosphonates e.g aldendronic acid 1-weekly
- and calcium and vitamin D (adCal)

Second line: if bisphosphonates not tolerated/ineffective
* Denosumab (monoclonal antibody that targets osteoclasts)
* and calcium and vitamin D (adCal)

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12
Q

Bisphosphonate options

A

1- Weekly
- Oral Alendronate (most popular)
- Oral Risedronate

1- Yearly
if alendronate not tolerated
- Zolendronic acid infusion

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13
Q

how much calcium and vitamin D

A

Calcium (at least 1000mg)
Vitamin D (400-800 IU)

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14
Q

Bisphosphonates have some important side effects:

A
  • Reflux and oesophageal erosions
  • Atypical fractures (e.g., atypical femoral fractures)
  • Osteonecrosis of the jaw (regular dental checkups are recommended before and during treatment)
  • Osteonecrosis of the external auditory canal
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15
Q

how should bisphosphonates be taken

A

taken on an empty stomach with a full glass of water. Afterwards, the patient should sit upright for 30 minutes before moving or eating to reduce the risk of reflux and oesophageal erosions.

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16
Q

osteomalacia

A

softening of the bones generally secondary to vitamin D deficiencies leading to incomplete mineralisation of bone

In children: rickets

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17
Q

RICKETS

A

rickets is characterised by defective mineralisation of the growth plate cartilage leading to skeletal deformities and reduction of growth secondary to vitamin D deficiency and subsequent incomplete bone mineralisation.

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18
Q

risk factors for osteomalacia

A
  • Dark skin, especially in South Asian, African-Caribbean, and Middle-Eastern people
  • Vitamin D deficiency is as high as 94% in otherwise healthy South Asian adults*
  • Family history of vitamin D deficiency
  • Age >65
  • Pregnancy
  • Obesity
  • Covering of the face and body
  • Housebound/institutionalised patients
  • Poverty
  • Vegetarianism
  • Alcoholism
  • Living in a high altitude
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19
Q

causes of low vitamin D

A

1) Most commonly due to insufficient exposure to sunlight and nutritional deficiency

2) GI malabsorption:

  • Stomach and bowel resections
  • Cystic fibrosis
  • Biliary disease
  • Crohn’s disease
  • Coeliac disease

3) Liver disease
4) Renal disease e.g. CKD
5) Drugs: anticonvulsants, rifampicin, HAART and cholestyramine

20
Q

presentation of osteomalacia

A
  • Myalgia is the most common presenting complaint
  • Bone pain
  • Lethargy
  • Fractures may be seen
21
Q

Signs on Examination of osteomalacia

A
  • Proximal muscle weakness
  • Muscle wasting associated with proximal muscle weakness
  • Waddling gait if the bone pain/proximal muscle weakness is severe
22
Q

investigations for osteomalacia

A

The first investigations involve looking at the patient’s bone profile:

Serum calcium level:

  • Normal or low

Serum 25-hydroxyvitamin D (25-OH cholecalciferol) level:

  • Low (<24nmol/L)

Serum phosphate level:

  • Low

* Serum alkaline phosphatase:

  • High

* Serum parathyroid hormone level (PTH):

  • High

Urea and electrolytes (U&Es):

  • To screen for kidney disease
23
Q

management of osteomalacia

A

1st line:
* Vitamin D and calcium supplementation
* Cholecalciferol and calcium carbonate is an example

2nd line:
* Vitamin D metabolite and calcium supplementation
* Calcitriol and calcium carbonate
* Used if first-line measures are ineffective or patients with renal disease

24
Q

Paget’s disease of bone

A

is a result of increased but uncontrolled bone turnover, leading to the development of new bone that is disorganised, mechanically weaker, and more liable to pathological fractures and deformity.

Cause unknown

  • caused by increased osteoclast and osteoblast activity
  • causes areas of high density (sclerosis) and low density (lysis) -> enlarged misshapen bones

Particularly affects axial bones
- head and spine

25
Q

risk factors for pagets disease

A
  • Family history
  • Age >50 years
  • Male sex
26
Q

presentation of pagets disease of the bone

A
  • Most patients are asymptomatic
  • Bone pain in the pelvis, lumbar spine, or femur
  • If untreated, features of tibial bowing prognathism, and bossing of the skull may be seen
  • Pathological fractures may be the presenting complaint
27
Q

osteomalacia vs pagets

A
  • Difficult to differentiate
  • Osteomalacia has bone pain from its onset
  • Most people with Paget’s disease of bone are asymptomatic
  • Osteomalacia: low serum vitamin D and raised ALP
  • Paget’s disease of bone: classically isolated raised ALP
28
Q

investigations for pagets

A

Bone profile tests should be carried out:

  • All results are normal except for an isolated rise in ALP

Plain X-rays are then carried out of the affected regions:

  • Lytic changes seen often in the skull (cotton wool)
  • In later stages, sclerotic changes are seen
  • The pelvis, long bones, and skull are the most common sites of abnormal bone
  • A skull x-ray may show a thickened vault
29
Q

management of pagets disease of the bone

A

If patients are asymptomatic:
* 1st line: observation and preventative measures

If patients are asymptomatic but have a high risk of complications:
* 1st line: bisphosphonate or calcitonin (less commonly used)

If patients are symptomatic:
* 1st line: bisphosphonate or calcitonin (less commonly used)

30
Q

complications of pagets

A
  • Kidney stones
  • Deafness/tinnitus secondary to cranial nerve entrapment
  • Spinal stenosis
  • Arthritis
  • Development of osteosarcoma – rare
  • High-output cardiac failure – extremely rare
  • Due to high blood flow to highly metabolically active bone sites
31
Q

Osteogenesis imperfecta

A

Osteogenesis imperfecta is a genetic condition that results in brittle bones that are prone to fractures. It is also knowns as brittle bone syndrome. It is caused by a range of genetic mutations that affect the formation of collagen. Collagen is a protein that is essential is maintaining the structure and function of bone, as well as skin, tendons and other connective tissues. There are 8 types of osteogenesis imperfecta depending on the underlying genetic mutation, and they vary in their severity.

32
Q

presentation of osteogenesis imperfecta

A

Osteogenesis imperfecta presents with recurrent and inappropriate fractures. There are several associated features:

* Hypermobility
* Blue / grey sclera (the “whites” of the eyes)

* Triangular face
* Short stature
* Deafness from early adulthood
* Dental prOsteogenesis imperfecta presents with recurrent and inappropriate fractures. There are several associated features:

33
Q

investigations for osteogenesis imperfecta

A

clinical diagnosis

bone profile blood tests will be all normal

34
Q

The Ehlers-Danlos syndromes (EDS)

A

are a group of heritable connective tissue disorders, whose manifestations consist of joint hypermobility, skin hyperextensibility, and tissue fragility. There are 13 subtypes of EDS

Hypermobile EDS most common form

Pathophysiology
- defect in collagen

35
Q

Ehlers-Danlos presentation

A
  • Stretchy and fragile skin
  • Joint hypermobility
  • Joint pain after exercise or inactivity
  • Recurrent joint dislocation
  • Easy bruising
  • Autonomic dysfunction leading to dizziness and syncope (POTS)
  • Pelvic organ prolapse
  • Gastro-oesophageal reflux disease
  • Aortic regurgitation
  • Mitral valve prolapse
  • Aortic dissection
36
Q

which score used to support diagnosis of EDS

A

EDS IS A CLINICAL DIAGNOSIS

The Beighton score is used to assess for hypermobility and support the diagnosis. One point is scored for each side of the body, with a maximum score of 9, if the patient can:

  • Place their palms flat on the floor with their straight legs (scores only 1)
  • Hyperextend their elbows
  • Hyperextend their knees
  • Bend their thumb to touch their forearm
  • Hyperextend their little finger past 90 degrees
37
Q

managment of EDS

A

Hypermobile Ehler-Danlos syndrome is a clinical diagnosis assisted by the Beighton score. Genetic testing is helpful in the other subtypes of EDS.

There is no cure for EDS. Management focuses on maintaining healthy joints, managing symptoms, supporting daily activities and monitoring for complications. This will involve:

Follow up with relevant specialists depending on the associated complications
Physiotherapy to strengthen and stabilise the joints and maintain good posture
Occupational therapy to maximise function
Moderating activity to minimise flares
Psychology may be required to support wellbeing

38
Q

Marfan syndrome

A

autosomal dominant connective tissue disorder due to mutations in the FB1 egen on chromosome 15 that codes for polypeptide fibrillin -1

39
Q

differences between marfans and EDS

A

Marfan syndrome is a critical differential diagnosis for hypermobility and needs to be excluded. Key features of Marfan syndrome are a high arch palate, arachnodactyly (long fingers) and increased arm span to body height ratio.

40
Q

presentation of marfans syndrome: general

A
  • Tall stature
  • Wide arm span
  • Arachnodactyly
  • Pes planus
  • Pectus excavatum
  • Scoliosis
  • Joint hypermobility
41
Q

presentation of marfans syndrome: cardiovascular

A
  • Thoracic aortic dilatation/rupture/dissection – usually asymptomatic
  • Aortic regurgitation
  • Mitral valve prolapse
  • Mitral regurgitation
  • Abdominal aortic aneurysms
  • Arrhythmia
42
Q

presentation of marfans syndrome: Respiratory features

A

Pneumothorax

43
Q

presentation of marfans syndrome: Facial features

A

Facial
* Long face
* High, arched palate
* Enophthalmos
* Down-slanting palpebral fissures
* Malar hypoplasia

Eye features
* Lens dislocation
* Closed-angle glaucoma
* High myopia

44
Q

investigations for Marfans

A

Echocardiography:
* May show aortic regurgitation/aortic root dilation/mitral regurgitation/mitral valve prolapse/ascending aortic dissection

CT thorax/MRI thorax:
* May show features mentioned in echocardiography

Slit-lamp eye exam with intra-ocular pressure measurement:
* May show dislocated lens
* May show increased intraocular pressure

Abdominal ultrasound:
* May show an abdominal aortic aneurysm
* May show aortic dissection of descending aorta

Chest x-ray:
* May show pneumothorax

CT abdomen/MRI abdomen:
* May show features mentioned in abdominal ultrasound

Blood screening for fibrillin-1 (FBN1) gene mutation:
* Positive in 99% of patients
* Must be interpreted in correlation to information from clinical examination

45
Q

management of Marfans

A

Management involves treating complications such as aortic root dilation, dislocated lenses, kyphosis and severe scoliosis.

46
Q

Monitoring for Marfans

A

Patients have regular echocardiography and CT scans to look for complications of MFS

47
Q

Complications of MFS

A

Complications

  • Aortic dissection or rupture
  • Chronic aortic dissection
  • Symptomatic aortic regurgitation
  • Pneumothorax
  • Severe mitral regurgitation
  • Heart failure
  • Symptomatic hernias
  • Infective endocarditis