Osteoarthritis and metabolic bone disease Flashcards Preview

Rheumatology > Osteoarthritis and metabolic bone disease > Flashcards

Flashcards in Osteoarthritis and metabolic bone disease Deck (36)
Loading flashcards...
1

Risk factors for Osteoarthritis (OA)

Old age -- begins in 40s and continues
Women>men
Obesity
Trauma (secondary OA)

2

Epidemiology of OA

Most common form of arthritis - 6% of adults over 30 have frequent knee pain with radiographic OA
9m in the UK -- 2nd biggest cause of severe disability
Slightly more females up to 45 then more males

3

Progression of OA - phase I

Chondrocyte injury due to biological and mechanical mechanisms

4

Progression of OA - phase II

Early OA -- chondrocytes proliferate and secrete inflammatory mediators, collagen, proteoglycans & proteases --> remodel matrix and initiate secondary inflammatory changes

5

Progression of OA - phase III

Late OA -- repetitive injury and chronic inflammation lead to chondrocyte drop out and loss of cartilage -- this leads to subchondral bone changes

6

Subchondral bone cysts

A common feature of late OA where small fractures through the articular bone allow synovial fluid to be forced into the subchondral region in a one way valve fashion

7

Radiological features of OA

Loss of joint space
Osteophytes
Sclerosis
Subchondral cyst formation

8

Osteophytes

Bony spurs which form along joint margins -- most commonly associated with OA
Cause pain and restrict movement

9

Clincial features of OA in a joint

Pain (with activity)
Bony swelling & periarticular tenderness
Reduced movement
Stiffness (after rest)
Joint crepitus

10

Treatment of OA

Lifestyle measures -- weight loss, exercise/physiotherapy, orthotic footwear
Analgesia -- NSAIDs/Opiates or local injection (hyaluronic acid). Topical capsaicin.
If joint is failing consider osteotomy or replacement

11

Glucosamine for OA

Cheap, safe and ineffective
Evidence is mixed, showing short term benefit but not recommended as not cost effective

12

Intra-articular injections

Hyaluronic acid -- weakly effective at reducing pain
NSAIDs -- Minimal benefit & only short term
Steroids -- immediate relief but not long term benefit
Capsaicin

13

Commonly used NSAIDs in OA

Ibuprofen, Diclofenac, Naproxen -- GI side effects
Celecoxib (selective COX-2 inhibitor) - cardiac side effects
Paracetamol -- Relieves 50% of pain but dangerous in overdose and pts dislike taking multiple tabs a day

14

Metabolic bone diseases

Osteoporosis -- weak bones at risk of fracture
Osteomalacia -- pain and weakness due to bone softness
Pagets disease -- pain and weakness due to deranged bone remodelling

15

Osteoporosis

Bone thinning due to increased resorption and decreased production, most commonly due to low post menopausal estrogen or prolonged steroid use
This increases the risk of hip or spine fractures and is a major health problem

16

Risk factors for Osteoporosis (5)

Age and women (menopause) and drugs (steroids)
Family history
Chronic inflammatory diseases (RA)

17

Diagnosis of Osteoporosis

Often happens after a pathological fracture
X-rays demonstrating thinning of the bone and confirmed by DEXA scan

18

DEXA scan

Using X rays it can establish the bone density in the neck of the femur and the lumbar spine.
Gives a general score (T) and score related to age and gender (Z) -- Severe (established) osteoporos is T-score <-2.5 and 1+ osteoporotic fractures
Scores should be adjusted if the pt is taking strontium

19

Established drugs for preventing osteoporosis

Calcium and vitamin D
Bisphosponates (Alendronate, Risedronate, Ibandronate)
HRT or Selective Oestrogen Recpetor Modulators (SERM) (Raloxifene)

20

Newer drugs for preventing osteoporosis

Strontium ranelate
Teriparatide (recombinant PTH)

21

Bisphosponates

Slow the loss of bone by blocking bone resorption and inducing osteoclasts to undergo apoptosis
SE: GI and oesophagus erosions and inflammation and possible risk of oesophageal cancer, possibly AF in women

22

Osteomalacia

Pain and weakness due to softening of bone -- due to inadequate Vitamin D & calcium --> low dietary intake, insufficient sun exposure, Vit D malabsorption, Metabolic disorders, Renal failure

23

Symptoms of osteomalacia

Diffuse bone pain (hips particularly)
Muscle weakness
Symptoms of hypocalaemia (numbness around the mouth or fingers)
Hand or feet spasms

24

X-rays of osteomalacia

Pseudofractures (looser's zones) are bands of thinning which develop and induce periosteal thickening and callose formation giving the appearance of a fracture

25

Treatment of Osteomalacia

Calcium and vit D to correct imbalance

26

Paget's disease

Increased rate of bone remodelling leading to pain, bone enlargement and thickening -- increased risk of fracture and other complications

27

Treatment of Paget's disease

Bisphosphates to slow bone resorption

28

Rickets

Osteomalacia in children

29

Skeletal dysplasias

Ehlers-Danlos syndrome
Marfans syndrome
Osteogenesis imperfecta
Osteopetrosis
Achondroplasia

30

Ehlers-Danlos syndrome

A heterogenous group of collagen disorders --> 10 types varying in degrees of skin fragility & hyperextensibility and joint hypermobility
Types I,II,III, IV, VII are autosomal dominant
Type VI is autosomal recessive
Types V,VIII, IX and X are rare and less is know