Bone and Joint Pathodiagnosis Week 5

What is the name of the skin disorder characterized by proliferation of the epidermis?

Psoariatic arthritis

What % of PA patients have an associated arthropathy?

5-8%

What is the mean age of onset of PA?

27 yo

How long after incidence of psoriasis can it take for PA to set in?

20 years

What are the possible etiologies of PA?

genetic factors, trauma, infection, stress (etiology is unknown)

What is auspitz sign?

bleeding after peeling off psoriatic scales

On what surfaces is psoriasis found?

Extensor surfaces (elbow, knee, scalp, and back)

What nail sign is associated with psoriasis?

Pitting

What % of posriasis patients have nail pitting?

40%

Where is PA found?

1 large joint and 1-2 interphalangeal joints

What is the AKA for dactylitis?

Sausage digit

What joints are affected by dactylitis in PA?

Knee

PIP

MTP

Ankle

MCP

DIP

What is the primary x-ray finding of PA

marginal bone erosions tapering to a pencil-in cup deformity

What is the AKA for pencil-in-cup deformity?

"mortar and pestle" or "mushroom and stem"

What type of erosion is formed by periostitis in PA?

Mouse ear erosions

What % of PA patients have involvement of the SI joint?

30-50%

T or F: PA affects the SI joint bilaterally

False (asymmetrical sacroiliitis more so than in AS)

T or F: PA causes marginal syndesmophytes in the spine

False (it causes non-marginal syndesmophytes)

What lab findings accompany PA?

Increased ESR

RF

Positive HLA-B27 (in some patients)

What is the AKA of Reiter's syndrome?

Reactive arthritis

What is the triad of Reiter's syndrome?

conjunctivitis, urethritis, arthritis

What demographic is most affected by Reiter's syndrome?

Males (50x more common)

age 20-40

What bacteria is the primary cause of Reiter's syndrome?

Chlamydia Trachomatis

How long after contraction of Chlamydia does it take for urethritis to set in?

7-14 days

What complication of Reiter's syndrome can occur in women and children?

Dysentery

T or F: Reiter's syndrome arthritis presents symmetrically

False (asymmetric)

What forms does arthritic manifestations of Reiter's syndrome take?

polyarticular synovitis

periostitis

enthesopathy

What areas of the body are affected by Reiter's syndrome?

ankle, foot, spine

What is the DDX of Reiter's syndrome on x-ray?

Psoriatic arthritis

What joint of the foot is most commonly affected by Reiter's syndrome?

Interphalangeal joint of the big toe

What is the name of the X-ray sign of Reiter's syndrome involving soft tissue swelling, erosions, and fluffy periostitis at insertions of the achilles and plantar tendons?

Lover's heel

What % of Reiter's syndrome patients present with lover's heel?

50%

What % of Reiter's syndrome patients have involvement of SI joints?

50%

T or F: SI joint sclerosis in Reiter's syndrome is asymmetrical, more so than AS

True

What is the name of the group of GI disorders producing articular abnormalities?

Enteropathic arthropathy

What age group is most affected by EA?

Young adults

What causes the inflammation of EA?

Antigen released from bowels in an antigen/antibody complex

What are the most common causes of EA?

Ulcerative collitis

Regional Enteritis (Crohn's disease)

inflammatory bowel disorders

What are symptoms of inflammatory bowel disorders?

chronic diarrhea, abdominal pain, fever, anorexia, weight loss, etc.

T or F: EA is identical to AS in terms of its changes to the SI joint

True

T or F: HLA B27 is often found in EA patients

True

T or F: Most EA patents are RF positive

False (RF negative)

What is the primary form of metabolic arthritis?

Gout

What is the root cause of gout?

Defect in purine metabolism leading to hyperuricemia

What is deposited in joint tissue in gout patients?

monosodium urate crystals

What gender is more affected by gout?

Males (95%)

What is the most common inflammatory disease in men over 30 yo?

Gout

What is the peak incidence of gout?

40-50 yo

What is the most common etiology of gout?

primary gout (genetic disorder) (overproduction and under excretion of uric acid)

What are the 4 states of gout?

Asymptomatic hyperuricemia

Acute gouty arthritis

chronic gouty arthritis

tophus formation

Which stage of gout involves formation of monosodium urate crystals in joint fluid and synovial membrane?

Acute gouty arthritis

Which stage of gout leads to acute inflammatory synovitis?

Acute gouty arthritis

Which stage of gout results from progressive precipitation of urate into synovial linings?

Chronic gouty arthritis

Which stage of gout leads to synovial proliferation, pannus formation, destruction of cartilage, and erosion of bone?

Chronic gouty arthritis

Which stage of gout is defined by local accumulation of monosodium urate crystals surrounded by an intense inflammatory reaction?

Tophus formation

What is the most common site of initial formation of gout?

1st metatarsophalangeal joint (50% initial, 85% total affected)

What joints are affected by gout?

MTP joints, ankle, knee, and hands

What is the pathognomonic lesion of gout?

Tophus

What % of patients reach the chronic phase of gout?

15-20%

What is the classic x-ray finding of gout?

overhanging margin sign

What are the lab findings of gout

Sodium urate crystals in synovial fluid and hyperuricemia

What foods should be reduced to reduce gout symptoms?

protein, fat, alcohol, and caffeine

What foods should be increased to reduce gout symptoms?

Water and fresh cherry juice

What are the AKAs of CPPD?

Pseuodgout

Chondrocalcinosis

Calcium pyrophosphate deposit

What causes CPPD?

Calcium pyrophosphate crystals deposited in the joint tissues

What gender is most affected by CPPD?

Equal sex distribution

What age is most affected by CPPD?

Greater than 30 yo

Peak incidence is 60 yo

What joints are affected by CPPD?

knees

ankles

shoulders

ankles

wrists

hands

What joint does CPPD most affect?

Knee

What is the primary X-ray finding of CPPD?

Osteoarthritis-like changes in unusual locations (shoulders, MCP)

What is the treatment of CPPD?

Indicine or draining synovial fluid

What are the potential sites of CPPD calcification?

hyaline cartilage or fibrocartilage of the knee

What are the 3 most common locations of CPPD?

Knee

Triangular fibrocartilage of the wrist

Pubic symphysis

What disorder will most likely present with degenerative changes in unusual locations?

CPPD