Joint Pathology

Question 1

Characteristics of osteoarthritis (OA)

Answer 1

Joint degeneration with loss of articular cartilage, with none to minimal inflammation.

It is the most common form of arthritis

Insidious onset of joint stiffness; deep aching joint pain, which worsens with repetitive motion; decreased range of motion, crepitus and joint effusions and swelling

Xray shows narrowing of the joint space due to loss of cartilage, osteosclerosis, bone cysts and osteophytes

Affects weight-bearing joints (knees, hips and spine) often with asymmetrical involvement

May also be present:
Eburnation
Bone cysts
Loose bodies (joint mice)
Osteophytes (bone spurs)
Heberden nodes or Bouchard node

Question 2

What are Heberden nodes?

Answer 2

Osteophytes at the distal interphalangeal (DIP) joints

Question 3

What are Bouchard nodes?

Answer 3

Osteophytes at the proximal interphalangeal (PIP) joints

Question 4

Characteristics of Rheumatoid arthritis (RA)

Answer 4

Systemic, chronic, inflammatory disease characterized by progressive arthritis, production of rheumatoid factor, and extra-articular manifestations

Most commonly affects the hand, wrist, knee, and ankle joints and the involvement is symmetrical.

There is often morning stiffness which improves with activity.

Typically fusiform swelling, redness and warmth of the PIP joints

Xray shows juxta-articular osteroporosis and bone erosions

Question 5

Characteristics of seronegative spondyloarthropathies

Answer 5

Group of disorders characterized by the following:

Rheumatoid factor seronegativity
Involvement of the sacroiliac joint
Association with HLA-B27

Question 6

Characteristics of ankylosing spondylitis

Answer 6

Occurs predominantly in young men with HLA-B27 (90% of cases) usually involves the sacroiiliac joints and spine; and may be associated with inflammatory bowel disease

Question 7

Characteristics of reactive arthritis

Answer 7

Characterized by a classic traid of conjuctivitis, urethritis and arthritis.

The arthritis affects the ankles and knees.

It affects males more than females with onsetr age 20s-30s

Onset often follows a venereal disease or bacillary dysentry

Question 8

Characteristics of enteropathic arthritis

Answer 8

Occurs in 10-20% of patients with inflammatory bowel disease

Question 9

Characteristics of psoriatic arthritis

Answer 9

Affects 5-10% of patients with psoriasis is often a mild and slowly progressive arthritis with pathology similar to RA

Question 10

Characteristics of gout

Answer 10

Hyperuricemia and the deposition of monosodium urate crystals in joints will result in recurrent bouts of acute arthritis.

The hyperuricemia can be caused by overproduction or underexcretion of uric acid

Gout affects the great toe (podagra, characterized by an exquisitely painful and inflamed big toe), ankle, heel and wrist

Question 11

Characteristics of primary gout

Answer 11

90%

Idiopathic affects males more than females and is typically seen in older men

Question 12

Characteristics of secondary gout

Answer 12

10%

Seen with excessive cell breakdown (chemotherapy), decreased renal excretion (drugs) and Lesch-Nyhan syndrome

Question 13

Characteristics of pseudogout

Answer 13

Chondrocalcinosis

Deposition of calcium pyrophosphate crystals in joints, leading to inflammation.

Affected patients are usually age>50

The knee joint is most commonly involved

Question 14

Characteristics of suppurative arthritis

Answer 14

May result from seeding of the joint during bacteremia

Other routes include spread from an adjacent site of infection and direct inoculation

Causes tender, painful, swollen, and erythematous joint

Large joints are most often infected

Question 15

What organisms cause suppurative arthritis?

Answer 15

Gonococci 
Staphylococcus
Streptococcus
H. influenzae
Gram-negative bacilli

Question 16

Characteristics of lyme disease

Answer 16

Caused by spirochete Borrelia burgdorferi

The disease is arthropod-borne, spread by deer ticks (Ixodes dammini)

Symptoms are skin rash (erythema chronicum migrans) and migratory arthritis involving the knees, shoulders, and elbows.

Question 17

Characteristics of Charcot joint

Answer 17

Refers to joint damage secondary to impaired joint innervation (neuropathy), leading to an inability to sense pain.

The damage also leads to destruction of joint surfaces, debris in joints, deformity and dislocations

Question 18

Characteristics of juvenile idiopathic arthritis

Answer 18

Present with arthritis before age 16 and persist for at least 6 weeks

Clinical features:
Oligoarthritis is more common

Systemic disease is more frequent

Large joints are affected more often than small joints

Rheumatoid nodules and rheumatoid factor are usually absent

Antinuclear antibody (ANA) seropositivity is common