2.2 Osteoarthritis + Other Muscoskeletal Conditions

Question 1

Single joints arthritis (or monoarthritis) is the acute onset of pain + swelling in a single joint. What are some of the causes of this?

Answer 1

Trauma
Septic arthritis (infection)
Crystal arthrtitis
Reactive arthritis (infection causing autoimmune resonse)
Osteomyelitis
Haematological conditions

Question 2

Polyarthritis is pain and swelling in >5 joints or joint groups. What are some of the causes of this?

Answer 2

Viral illness
Osteoarthritis
Rheumatoid arthritis
Psoriatic arthritis
Lupus

Question 3

In healthy bone, fractures mainly occur due to significant trauma. How are pathological fractures different?

Answer 3

Occur due to low trauma (falling from standing position)

Includes osteoporotic fractures, malignancy + other bone disease

Question 4

Serious causes of back pain are not very common. What are some more common causes of back pain?

Answer 4

1. Mechanical (paraspinal spasm + tenderness = limited movement)
2. Disc disease such as disc prolapse + nerve root compression
3. Degeneration of tendons + ligaments through overuse or injury

Question 5

The gut, kidney, and organs are involved in regulating calcium. What are the regulating hormones involved?

Answer 5

1. Parathyroid hormone (from parathyroid glands)
2. Calcitonin (from thyroid glands)

Question 6

How do parathyroid hormones (PTH) and calcitonin maintain calcium homeostasis?

Answer 6

1. PTH releases Ca from bone when levels are low
2. Increases conversion of vit D hormone (calcitrol) in kidney
3. Calcitrol increases absorption of Ca from gut

Calcitonin = minor role inhibiting osteoclast action in response to gut hormones + high Ca (NOT ESSENTIAL)

Question 7

Osteoporosis is where bone mass and bone density is decreased. It’s the result of a defect in peak bone mass and/or accelerated bone loss. What are the characteristics of peak bone mass?

Answer 7

Accrues up unti llate 20s

Stable in adults, but women suffer significant loss at menopause

Affected by diet, activity, smoking, and vit D levels

Question 8

What are the risk factors for osteoporosis?

Answer 8

Age, Gender, Ethnicity

Early menopause (~1% after 30, ~5% after menopause) and/or late menarche

Family history

Lifestyle factors

Certain medications + diseases

Question 9

What is osteoarthritis?

Answer 9

Most common arthritis

Affects fingers, hips, knees, and cervical + lumbar spine

Question 10

What are the causes of osteoarthritis?

Answer 10

Primary = idiopathic (unknown cause)

Secondary = chronic joint trauma (repetitive joint overloading), acute joint trauma, and metabolic + neurological conditions

Obesity (loading + cytokine effects)

Joint alignment / shape

Question 11

What happens to the joints in osteoarthritis?

Answer 11

Loss of articular cartilage

Bone architecture changes (sclerosis)

Osteophytes form at margin = limitation

Joint remodelling + bony enlargement + capsular thickening + deformity

Inflamed joints (synovitis) = not significant clinical feature

Question 12

What are the clinical features of osteoarthritis?

Answer 12

Onset over months + years
Intermittable + variable
Pain (relieved by rest)
Restricted joint movement
Crepitus (creaking from rough surfaces)
Bony swelling + margins
Muscle weakness from reduced activity
Normal ESR / CRP + serology

Question 13

What is ESR?

Answer 13

Erythrocyte sedimentation rate

Measures anticoagulation rate of RBCs

Elevated in inflamamtory conditions

Question 14

What is CRP?

Answer 14

C Reactive Protein

Circualting concentration rise in response to inflammation

Question 15

What is septic (infective) arthritis and how is it commonly caused?

Answer 15

Rapid + infective joint disease

Haematogenous spread from infection or joint wound

More common in patients with compromised immune or joint disorders

Question 16

What are involved organisms, clinical features, and treatments for septic arthritis?

Answer 16

Organisms = S. Aureus + various streptococci

Clinical = fever + acute monoarthritis with swelling + dysfunction

Tx = IV antibiotics, joint aspiration, and physiotherapy

Question 17

What is osteomyelitis + how is it commonly caused?

Answer 17

Infection of bone + marrow

Can be any joint, usually long bones + adjacent bones

Usually caused by haematogenous spread of bacteria

Question 18

What are the clinical features and management of osteomyelitis?

Answer 18

Clinical = fever, pain, movement limitation in adjacent joint

Management = IV antibiotics for 2 weeks, then 4 weeks oral antibiotics

Early diagnosis + tx = crucial to avoiding necorosis

Question 19

When should Ab phrophylaxis be considered if pt has had joint placement?

Answer 19

If dental tx req within 3 monts of prosthetic joint placement

If pt is immune compromised

If artifical joint failing

Previous hx of infected artifical joints

Question 20

What is carpal tunnel syndrome?

Answer 20

Nerve entrapment syndrome caused by compression of median nerve at wrist

Causes numbness + pain in areas of hand supplied by median nerve

Question 21

What is the aetiology + treatment of carpal tunnel syndrome?

Answer 21

Aetiology = idiopathic, obesity, pregnancy, diabetes, hypothyroidism

Tx = steroid injections or surgery to decompress nerves

Question 22

What is myasthenia gravis?

Answer 22

Autoimmune disease where antibodies interfere with motor nerve conduction

Muscles become easily fatigued (up resp tract)