Joints & connective tissues

Question 1

Master switch. Chondrocytes derived from mesenchymal precursors

Answer 1

SOX-9 transcription factor

Question 2

Effects of aging and osteoarthritis on cartilage

Answer 2

Opposite except for proteoglycan content (both decrease)

Question 3

Effect of osteoarthritis on cartilage

Answer 3

Water increased
Proteoglycan decreased
Keratin sulfate decreased
Proteoglycan degradation increased

Question 4

Extreme form of osteoarthritis caused by disturbed sensory innervation

Answer 4

Charcot’s arthropathy

Question 5

Most common overall cause of charcot’s arthropathy in foot and ankle

Answer 5

Diabetes

Question 6

Most common cause of charcot’s arthropathy in upper extremity joints

Answer 6

Syringomyelia

Question 7

Increasingly used in treatment of RA

Answer 7

DMARDs (infliximab, etanercept).- target TNF alpha

Question 8

Juvenile idiopathic arthritis

Answer 8

Includes both JRA and RA
Typically Manifests before age 4
Commonly involves knee, wrist and hand
Slit lamp examination needed twice yearly due to iridocyclitis which can lead to rapid vision loss

Question 9

Gout

Answer 9

Monosodium urate crystals in joints

Punched out periarticular lesions

Question 10

Initial treatment for gout

Answer 10

Indomethacin

Question 11

Allopurinol

Answer 11

Lowers serum acid levels chronically

Question 12

Cholchicine

Answer 12

Used for prophylaxis

Inhibits(?) inflammatory mediators

Question 13

Four transitional tissues of tendon insertion

Answer 13

Tendon
Fibrocartilage
Mineralized fibrocartilage (Sharpey’s fibers)
Bone

Question 14

Collagen type. Early tendon healing

Answer 14

Type III

Question 15

Repair of tendons. Weakest to strongest

Answer 15

7-10 days weakest
3-4 weeks original strength
6 months maximum strength

Question 16

Two types of ligament insertion

Answer 16

Indirect - more common. Superficial fibers insert at Acite angles into periosteum

Direct - both superficial and deep fibers insert through ligament, fibrocartilage, Sharpey’s fibers and bone

Question 17

Collagen type. Tendons and ligaments

Answer 17

Type I

Ligaments have fibers that are more variable and have higher elastin content

Question 18

Composition of articular cartilage

Answer 18

Water (60% to 80% of wet weight)
Collagen (95% type II) (10-20%wet weight but more than 50% dry weight)
Proteoglycans (10-15% wet weight)
Chondrocytes (5% wet weight)