Musculoskeletal / Rheumatology

What is the pathophysiology of Osteoarthritis (OA)?

Degenerative joint disease → cartilage loss → osteophytes → subchondral sclerosis → joint space narrowing.

What are the risk factors for Osteoarthritis (OA)?

Age, obesity, repetitive joint use, genetics, previous injury.

What are the clinical features of Osteoarthritis (OA)?

Joint pain worsens with activity, improves with rest; Morning stiffness <30 min; Heberden’s nodes (DIP), Bouchard’s nodes (PIP).

What imaging is used for diagnosing Osteoarthritis (OA)?

X-ray: joint space narrowing, osteophytes, subchondral sclerosis.

What are the treatment options for Osteoarthritis (OA)?

Lifestyle changes: weight loss, exercise; NSAIDs / acetaminophen; Intra-articular corticosteroids; Joint replacement if severe.

What is a mnemonic for Osteoarthritis (OA)?

OA = Old Age Activity → pain worsens with activity.

What is the pathophysiology of Rheumatoid Arthritis (RA)?

Autoimmune inflammatory arthritis → synovial hyperplasia → pannus → joint destruction.

What are the risk factors for Rheumatoid Arthritis (RA)?

Female, 30–50 years, HLA-DR4, smoking.

What are the clinical features of Rheumatoid Arthritis (RA)?

Symmetrical joint involvement (MCP, PIP); Morning stiffness >1 hour; Swan neck & boutonniere deformities; Rheumatoid nodules.

What laboratory findings are used to diagnose Rheumatoid Arthritis (RA)?

Labs: +RF, +anti-CCP, ↑ESR/CRP; X-ray: joint erosion, osteopenia.

What are the treatment options for Rheumatoid Arthritis (RA)?

DMARDs: Methotrexate (first-line); Biologics: TNF inhibitors, IL-6 inhibitors; NSAIDs & corticosteroids for symptom control.

What is a mnemonic for Rheumatoid Arthritis (RA)?

RA = Red & Angry Joints → symmetrical inflammation.

What is the pathophysiology of Gout?

Monosodium urate crystals → inflammatory arthritis, usually due to ↓ excretion or ↑ production.

What are the risk factors for Gout?

Male, alcohol, red meat, diuretics, CKD, obesity.

What are the clinical features of Gout?

Acute, sudden, severe joint pain (classically first MTP – podagra); Swelling, erythema, warmth.

What is used for diagnosing Gout?

Joint aspiration: negatively birefringent crystals; ↑ serum uric acid.

What are the treatment options for Gout?

Acute: NSAIDs, colchicine, corticosteroids; Chronic: allopurinol (XO inhibitor), febuxostat.

What is a mnemonic for Gout?

Gout = Great Toe → podagra classic.

What is the pathophysiology of Pseudogout (CPPD)?

Calcium pyrophosphate deposition in cartilage → acute arthritis.

What are the clinical features of Pseudogout (CPPD)?

Knee most commonly; Acute, painful, swollen joint.

What is used for diagnosing Pseudogout (CPPD)?

Joint aspiration: positively birefringent rhomboid crystals; X-ray: chondrocalcinosis.

What are the treatment options for Pseudogout (CPPD)?

NSAIDs, colchicine, steroids.

What is the pathophysiology of Ankylosing Spondylitis (AS)?

Chronic inflammatory disease → axial skeleton fusion; Strongly associated with HLA-B27.

What are the clinical features of Ankylosing Spondylitis (AS)?

Chronic low back pain, worse at night, improves with activity; Sacroiliac joint involvement → stiffness; Extra-articular: uveitis, aortic regurgitation.

What imaging is used for diagnosing Ankylosing Spondylitis (AS)?

X-ray / MRI: sacroiliitis, bamboo spine; Labs: ↑ESR/CRP, HLA-B27 positive.

What are the treatment options for Ankylosing Spondylitis (AS)?

NSAIDs (first-line); TNF inhibitors for refractory cases; Physical therapy.

What is a mnemonic for Ankylosing Spondylitis (AS)?

AS = Axial Spine stiff.

What is the pathophysiology of Systemic Lupus Erythematosus (SLE)?

Autoimmune, type III hypersensitivity → immune complex deposition → multiorgan inflammation.

What are the risk factors for Systemic Lupus Erythematosus (SLE)?

Female, reproductive age, African/Asian descent, HLA-DR2/DR3.

What are the clinical features of Systemic Lupus Erythematosus (SLE)?

Malar rash, discoid rash; Photosensitivity; Oral ulcers; Arthritis (non-erosive, symmetric); Serositis, nephritis, hematologic abnormalities, CNS involvement.

What are the lab findings for diagnosing Systemic Lupus Erythematosus (SLE)?

ANA (sensitive); Anti-dsDNA, anti-Smith (specific); Complement low in active disease.

What are the treatment options for Systemic Lupus Erythematosus (SLE)?

Mild: NSAIDs, hydroxychloroquine; Moderate/severe: corticosteroids, immunosuppressants (azathioprine, cyclophosphamide, mycophenolate).

What is a mnemonic for Systemic Lupus Erythematosus (SLE)?

SOAP BRAIN MD – Serositis, Oral ulcers, Arthritis, Photosensitivity, Blood, Renal, ANA, Immunologic, Neurologic, Malar, Discoid.

What are the types of Scleroderma (Systemic Sclerosis)?

Limited (CREST): Calcinosis, Raynaud, Esophageal dysmotility, Sclerodactyly, Telangiectasia; Diffuse: widespread skin + organ involvement.

What are the clinical features of Scleroderma (Systemic Sclerosis)?

Skin thickening / tightening; Raynaud phenomenon; GI dysmotility; Pulmonary fibrosis / HTN.

What are the lab findings for diagnosing Scleroderma (Systemic Sclerosis)?

ANA positive; Anti-centromere: limited; Anti-Scl-70: diffuse.

What are the treatment options for Scleroderma (Systemic Sclerosis)?

Symptom-based: vasodilators for Raynaud, PPI for reflux, immunosuppressants for organ involvement.

What is a mnemonic for Scleroderma (Systemic Sclerosis)?

CREST = Limited scleroderma.

What is the pathophysiology of Polymyositis / Dermatomyositis?

Autoimmune → inflammation of skeletal muscles (proximal).

What are the clinical features of Polymyositis / Dermatomyositis?

Symmetrical proximal muscle weakness (shoulder/pelvis); Fatigue; Dermatomyositis: Gottron’s papules, heliotrope rash, shawl sign.

What are the lab findings for diagnosing Polymyositis / Dermatomyositis?

↑ CK, ↑AST/ALT/LDH; EMG: myopathic pattern; Muscle biopsy: endomysial inflammation.

What are the treatment options for Polymyositis / Dermatomyositis?

Corticosteroids; Immunosuppressants (methotrexate, azathioprine).

What is a mnemonic for Polymyositis / Dermatomyositis?

DM = Dermato + Muscle.

What is the pathophysiology of Osteoporosis?

↓ bone mass / density → fragile bones; Postmenopausal women (↓ estrogen), older men.

What are the clinical features of Osteoporosis?

Often asymptomatic; Fragility fractures: hip, vertebrae, wrist.

What imaging is used for diagnosing Osteoporosis?

DEXA scan: T-score ≤ -2.5; Labs: calcium, vitamin D, phosphate.

What are the treatment options for Osteoporosis?

Lifestyle: weight-bearing exercise, calcium + vitamin D; Bisphosphonates (alendronate), denosumab, teriparatide.

What is a mnemonic for Osteoporosis?

Osteo = Old bone breaks easily.

What are the causes of Infectious Arthritis?

Bacterial: Staph aureus most common; Gonococcal arthritis (sexually active).

What are the clinical features of Infectious Arthritis?

Acute, painful, swollen joint; Fever, limited ROM.

What is used for diagnosing Infectious Arthritis?

Joint aspiration: >50,000 WBC, gram stain/culture.

What are the treatment options for Infectious Arthritis?

Empiric IV antibiotics (vancomycin for staph); Gonococcal: ceftriaxone.

What are osteophytes in Osteoarthritis (OA)?

Bone spurs that develop as a result of joint degeneration and cartilage loss.

What is subchondral sclerosis in the context of Osteoarthritis (OA)?

Hardening of the bone just below the cartilage of a joint due to increased stress and loading.

What is Heberden’s node?

A bony growth that forms on the distal interphalangeal (DIP) joints in Osteoarthritis.

What is Bouchard’s node?

A bony growth that forms on the proximal interphalangeal (PIP) joints in Osteoarthritis.

What is a common non-pharmacological treatment for Osteoarthritis (OA)?

Physical therapy, which focuses on improving joint function and mobility.

What are TNF inhibitors used for in Rheumatoid Arthritis (RA)?

Biologic medications that decrease inflammation and prevent joint damage by blocking tumor necrosis factor.

What are Swan neck deformities?

Deformations that occur in the fingers due to Rheumatoid Arthritis, leading to hyperextension at the PIP joints and flexion at the DIP joints.

What are the common joint areas affected by Gout?

Most commonly affects the first metatarsophalangeal joint (big toe), but can also affect ankles, knees, and wrists.

What does negative birefringence indicate in gout diagnosis?

It indicates the presence of monosodium urate crystals in joint fluid.

What is chondrocalcinosis?

The presence of calcium pyrophosphate crystals in the cartilage, seen on X-rays in conditions like Pseudogout.

What is the role of corticosteroids in the treatment of Gout?

To reduce inflammation and pain during acute gout flares.

What is the relationship between HLA-B27 and Ankylosing Spondylitis (AS)?

HLA-B27 is a genetic marker strongly associated with an increased risk of developing AS.

What type of joint pain is typically associated with Ankylosing Spondylitis (AS)?

Chronically worsening low back pain and stiffness, particularly in the early morning or after periods of inactivity.

What does a 'bamboo spine' appearance indicate on X-ray for AS?

It reflects fusion of the vertebrae and is characteristic of advanced Ankylosing Spondylitis.

What is the first-line treatment for Osteoporosis?

Bisphosphonates, which help to prevent bone loss and reduce fracture risk.

Which laboratory test is often monitored in Systemic Lupus Erythematosus (SLE)?

Anti-double-stranded DNA and anti-Smith antibodies, which are more specific for lupus.