Basic Science

Question 1

3 parts of long bone

Answer 1

Diaphysis, Metaphysis, Epiphysis

Question 2

Diaphysis

Answer 2

• Shaft
• Made of thick Cortical bone
• Filled with bone marrow

Question 3

Metaphysis

Answer 3

• Widening of bone near the end

- Typically made of Cancellous bone

Question 4

Epiphysis

Answer 4

• End (usually articular) of bone

- Forms from secondary ossification centers

Question 5

Ossification in Long Bones

Answer 5

Enchondral; primary and secondary growth centers

Question 6

Ossification in Flat Bones

Answer 6

Intramembranous

Question 7

Woven Bone

Answer 7

Immature/pathologic; poorly organized; not stress oriented

Ex: fracture callus

Question 8

Lamellar Bone

Answer 8

Mature bone; highly organized w/ stress orientation; makes up mature cortical and cancellous bone

Question 9

Cortical (compact) bone

Answer 9

• Strong, dense bone
• Composed of multiple osteons
• Found in diaphysis of long bones

Question 10

Osteon

Answer 10

• Cortical bone

- Composed of concentric bone lamellae w/ central canal containing osteoblasts and arteriole

Question 11

Cancellous (spongy/trabecular) bone

Answer 11

• Crossed lattice structure
• High bone turnover rate
• Common site of osteoporosis
• Metaphysis/epiphysis of long bones

Question 12

Calcium hydroxyapatite

Answer 12

• Primary mineral in bone

- Adds compressive strength

Question 13

Collagen

Answer 13

• aka “osteoid” before mineralization

- Type 1 collagen gives tensile strength

Question 14

Proteoglycans

Answer 14

• Composed of hyaluronic acid backbone w/ multiple glycosaminoglycans
• Provides compressive strength

Question 15

Osteoblasts

Answer 15

• Produce bone matrix (“osteoid”)

Question 16

Osteoblast receptors

Answer 16

PHT, Vit D, glucosteroids, estrogen

Question 17

Osteocytes

Answer 17

• osteoblast surrounded by bone matrix

- Maintain and preserve bone

Question 18

Stages of fracture healing

Answer 18

Inflammation, Repair, Remodeling

Question 19

Inflammation stage of Fx healing

Answer 19

• Hematoma develops and supplies hematopoietic/osteoprogenitor cells
• Granulation tissue forms

Question 20

Repair stage of Fx healing

Answer 20

• Soft callus: cells produce a cartilage (soft) callus that bridges the bone ends (bridging callus)
• Hard callus: replacement of soft callus into immature (woven) bone (enchondral ossification)

Question 21

Remodeling stage of Fx healing

Answer 21

Immature (woven) bone is replaced by mature (lamellar) bone

Question 22

Joint Synovium

Answer 22

• Inner membrane lines the joint capsule
• “Makes” (filters plasma to produce) synovial fluid
  Synovial folds (plica) form normally but occasionally can be pathologic

Question 23

Cartilage: Hyaline

Answer 23

• Found in articular cartilage of synovial joints and cartilage in physes
• Contains type II collagen

Question 24

Fibrocartilage

Answer 24

• Found in meniscus, TFCC, vertebral disc

- Contains type I collagen

Question 25

Grade I Sprain

Answer 25

Stretching of ligament

Question 26

Grade II Sprain

Answer 26

Partial tear of ligament

Question 27

Grade III Sprain

Answer 27

Complete tear of ligament

Question 28

5 P's of Compartment Syndrome

Answer 28

Pain (on passive stretch), paresthesias, pallor, paralysis, pulselessness (late finding)

Question 29

Compartment Syndrome

Answer 29

Results from increased pressure within fibroosseous compartment

Question 30

Musculotendinous junction

Answer 30

- Transition from muscle to tendon | - Weakest portion of the myotendinous complex and site of most injuries