Bones and Joints

Question 1

How many bones?

Answer 1

206

Question 2

Bone divisions

Answer 2

Long bones (appendicular)
Flat bones (axial)

Question 3

Metaphysis

Answer 3

Contains growth plate, changes radically during growth.

Question 4

Mechanisms of bone formation

Answer 4

Endochondral ossification (long bones)
Intramembranous ossification (flat bones)

Question 5

Bones as storage sites

Answer 5

Calcium and phosphate

Question 6

Effects of vitamin D

Answer 6

Increased calcium absorption
Resorption of calcium
Bone mineralisation

Question 7

Causes of vitamin D deficiency

Answer 7

Lack of sunlight
Inadequate intake
Abnormal intestinal absorption (chronic diseases - absorptive, metabolic)

Question 8

Osteopenia (osteomalacia) mechanism

Answer 8

Decreased mineralisation (calcification of bones)

Question 9

Osteopenia symptoms

Answer 9

Bones are soft (pliable)
Increased fractures
In children, constellation of failure to grow - deformities and bowing.

Question 10

Osteoporosis mechanism

Answer 10

Reduction of bone mass
Often multifactorial

Question 11

Primary osteoporosis

Answer 11

Idiopathic
- Age, menopause, diet, lifestyle, low initial bone mass.

Question 12

Secondary osteoporosis

Answer 12

Due to an identifiable cause
- Hormonal imbalances
Dietary insufficiency
- Drugs
- Tumours (hormones, direct destruction)
- Immobilisation

Question 13

Osteoporosis symptoms

Answer 13

Pathologic fractures (distal radius, proximal femur, spinal)
Spine (loss of height, thoracic kyphosis)

Question 14

Thoracic kyphosis

Answer 14

Forward curvature of the mid-back (thoracic spine)

Question 15

Osteoporosis fractures common in

Answer 15

Vertebrae, hips, distal radius

Question 16

Fracture definition

Answer 16

Disruption of the bone structure, often due to trauma

Question 17

Displaced fracture

Answer 17

Ends of bones not aligned

Question 18

Stress fractures

Answer 18

Due to repetitive loads and activity over time (common in foot of marathon runners)

Question 19

Comminuted fractures

Answer 19

Many breaks

Question 20

Pathologic fracture

Answer 20

Due to abnormal bone

Question 21

Fracture healing

Answer 21

1. Blood fills the gap and clots (minutes)
2. Inflammatory cells, fibroblasts, new capillaries use the blood clot framework ingrow. (days)
3. Soft tissue becomes transformed into woven bone (weeks)
4. Bone matures and is subject to stress, remodeling. (weeks-months)

Question 22

Appearance of woven bone

Answer 22

Unorganised, bones all over, no structure to osteons.
Mature bone is more homogenous from stress.

Question 23

Osteomyelitis definition

Answer 23

Infection of the bone, usually bacterial.
Introduced by trauma/inoculation (direct), from adjacent joints, or hematogenously (sepsis)

Question 24

Sequestrum

Answer 24

Necrotic, dead bone

Question 25

Involucrum

Answer 25

New bone surrounding infection

Question 26

Most common presentation of osteomyelitis

Answer 26

From diabetes, infection in foot

Question 27

Most bone tumours occur in who?

Answer 27

Children or young adults, each bone tumour as a preferred bone and site within the bone.

Question 28

Most common malignat bone tumour

Answer 28

Osteosarcoma

Question 29

Osteosarcoma incidence

Answer 29

Occurs in children and adolescents. Common in the metaphysis of long bones.

Question 30

Presentation of osteosarcome

Answer 30

Metastatic

Question 31

Treatment of osteosarcoma

Answer 31

Chemotherapy, surgery 60-70% will survive 5 years post-treatment

Question 32

Microscopic appearance of osteosarcoma

Answer 32

Malignant cells produce pink osteoid but without organisation. Too many, big, atypically shaped cells. Mitoses present.

Question 33

Meniscus

Answer 33

Fibrocartilage disc that absorbs shock in joints

Question 34

Osteoarthritis overview

Answer 34

Degenerative joint disease that affects weight-bearing joints. (incidence increases with weight and age). Due to wear and tear.

Question 35

Process of osteoarthritis

Answer 35

1. Cartilage damage and tears expose the bone 2. Boney sclerosis formation 3. Cysts form in bone 4. New nodules of bone project into joint space and adjacent soft tissue.

Question 36

Osteophytes

Answer 36

New nodules of bone

Question 37

Eburnation

Answer 37

Exposed bone, boney sclerosis that look like ivory, form in osteoarthritis.

Question 38

Appearance of advanced psteoarthritis

Answer 38

Osteophytes Periarticular fibrosis Calcified cartilage

Question 39

Symptoms of osteoarthritis

Answer 39

Pain, crepitus, swelling/inflammation, deformation, loss of mobiility, stiffness that improves with REST.

Question 40

Crepitus

Answer 40

Cartilage degeneration (sounds like rice crispies…)

Question 41

Rheumatoid arthritis overview

Answer 41

Systemic autoimmune disease affecting synovial joints (as well as other body systems), affects any age group.

Question 42

Characteristic features of rheumatoid arthritis

Answer 42

Chronic, systemic inflammation Serologic evidence (RhF) Extra-articular manifestations (splenomegaly, skin nodules)

Question 43

Mechanism of rheumatoid arthritis

Answer 43

Synovium becomes inflamed, inflammatory cells and fluid expand the space. Inflammation stimulates growth of vessels and proliferation of synovium, Produce factors that induce injury.

Question 44

Pannus

Answer 44

Abnormal, aggressive layer of inflamed synovial tissue that proliferates in joints, acting like a tumor-like tissue that erodes cartilage, bone, and ligaments in rheumatoid arthritis (RA)

Question 45

Microscopic appearance of rheumatoid arthritis

Answer 45

Inflammed synovial lining Dense lymphoplasmacytic inflammation (full of plasma cells) New vessels

Question 46

Symptoms of rheumatoid arthritis

Answer 46

Pain, joint deformity, limited mobility, contractures, stiffness that improves with MOVEMENT.

Question 47

Gout overview

Answer 47

Disease due to hyperurecemia, deposition of uric acid crystals.

Question 48

Primary gout

Answer 48

Metabolic - increased uric acid production Renal - Decreased excretion “Bad luck”

Question 49

Secondary gout

Answer 49

Due to malignancy, chronic kidney disease

Question 50

Where do uric acid crystals deposit?

Answer 50

Insoluble, lower temps encourage crystallisation. Usually big toe.

Question 51

Mechanism of goutt

Answer 51

Deposition of uric acid crystals induces inflammation and pain.

Question 52

Acute gout

Answer 52

Pain, swelling, problems with mobility, systemic, lasts days.

Question 53

Chronic gout

Answer 53

Bone deformities, gouty tophi