Rheumatoid arthritis


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Rheumatoid arthritis

Musculoskeletal system

Pediatric musculoskeletal conditions

Radial head subluxation (Nursemaid elbow)

Developmental dysplasia of the hip

Legg-Calve-Perthes disease

Slipped capital femoral epiphysis

Transient synovitis

Osgood-Schlatter disease (traction apophysitis)

Musculoskeletal injuries and trauma

Rotator cuff tear

Dislocated shoulder

Radial head subluxation (Nursemaid elbow)

Winged scapula

Thoracic outlet syndrome

Carpal tunnel syndrome

Ulnar claw

Erb-Duchenne palsy

Klumpke paralysis

Iliotibial band syndrome

Unhappy triad

Anterior cruciate ligament injury

Patellar tendon rupture

Meniscus tear

Patellofemoral pain syndrome

Sprained ankle

Achilles tendon rupture



Degenerative disc disease

Spinal disc herniation


Compartment syndrome


Bone disorders

Osteogenesis imperfecta


Pectus excavatum


Genu valgum

Genu varum

Pigeon toe

Flat feet

Club foot

Cleidocranial dysplasia



Bone tumors




Osteomalacia and rickets


Paget disease of bone


Lordosis, kyphosis, and scoliosis

Joint disorders



Spinal stenosis

Rheumatoid arthritis

Juvenile idiopathic arthritis


Calcium pyrophosphate deposition disease (pseudogout)

Psoriatic arthritis

Ankylosing spondylitis

Reactive arthritis


Septic arthritis


Baker cyst

Muscular disorders

Muscular dystrophy



Inclusion body myopathy

Polymyalgia rheumatica



Neuromuscular junction disorders

Myasthenia gravis

Lambert-Eaton myasthenic syndrome

Other autoimmune disorders

Sjogren syndrome

Systemic lupus erythematosus

Mixed connective tissue disease

Antiphospholipid syndrome

Raynaud phenomenon


Limited systemic sclerosis (CREST syndrome)

Musculoskeletal system pathology review

Back pain: Pathology review

Rheumatoid arthritis and osteoarthritis: Pathology review

Seronegative and septic arthritis: Pathology review

Gout and pseudogout: Pathology review

Systemic lupus erythematosus (SLE): Pathology review

Scleroderma: Pathology review

Sjogren syndrome: Pathology review

Bone disorders: Pathology review

Bone tumors: Pathology review

Myalgias and myositis: Pathology review

Neuromuscular junction disorders: Pathology review

Muscular dystrophies and mitochondrial myopathies: Pathology review


Rheumatoid arthritis


0 / 17 complete

USMLE® Step 1 questions

0 / 12 complete

High Yield Notes

15 pages


Rheumatoid arthritis

of complete


USMLE® Step 1 style questions USMLE

of complete

A 53-year-old woman comes to the emergency department because of abdominal pain and distention. The patient has had several episodes of emesis prior to arrival. Past medical history is notable for rheumatoid arthritis and gallstones treated with laparoscopic cholecystectomy. Temperature is 37.6°C (99.7°F), pulse is 96/min and blood pressure is 140/83 mmHg. Physical examination reveals diffuse tenderness to palpation of the abdomen and high-pitched bowel sounds on auscultation. Laboratory testing reveals the following findings:

 Laboratory value  Result 
 Sodium  145 mmol/L 
 Potassium  3.7 mmol/L 
 Chloride  102 mmol/L 
 Bicarbonate  30 mmol/L 

Imaging reveals obstruction of the small intestine. The patient is taken to the operating room, undergoes endotracheal intubation, and surgical adhesiolysis is performed. Three hours later, neurological examination reveals areflexia and impaired sensation in all extremities. Which of the following is the most likely explanation for the neurological defects?  

External References

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with rheumatoid arthritis p. 476

Anemia of chronic disease p. 429

rheumatoid arthritis p. 476

Carpal tunnel syndrome p. 455

rheumatoid arthritis p. 476


rheumatoid arthritis p. 476


rheumatoid arthritis p. 476

Methotrexate p. 446

rheumatoid arthritis p. 476


rheumatoid arthritis p. 476

Nonsteroidal anti-inflammatory drugs (NSAIDs) p. 499

rheumatoid arthritis p. 476


osteoarthritis/rheumatoid arthritis p. 476


rheumatoid arthritis p. 476

Rheumatoid arthritis p. 476

anemia of chronic disease and p. 429

autoantibody p. 113

azathioprine for p. 448

biliary cirrhosis p. 404

carpal tunnel syndrome and p. 456

celecoxib for p. 499

etanercept for p. 501

HLA-DR4 and p. 98

immunosuppressants p. 118

infliximab/adalimumab for p. 501

labs/findings p. 722

leflunomide for p. 499

methotrexate for p. 448

rituximab for p. 120, 450

uveitis p. 555

Sjögren syndrome p. 478

rheumatoid arthritis p. 476


rheumatoid arthritis p. 476



Sam Gillespie, BSc

In rheumatoid arthritis, “arthr-“ refers to joints, “-itis” means inflammation, and “rheumatoid” comes from rheumatism, which more broadly refers to a musculoskeletal illness.

So, rheumatoid arthritis is a chronic, inflammatory disorder that mostly affects the joints, but can also involve other organ systems like the skin and lungs as well.

Alright, so a healthy joint typically has two bones covered with articular cartilage at the ends.

Articular cartilage is a type of connective tissue that acts like a protective cushion - a lubricated surface for bones to smoothly glide against.

One type of joint, like the knee joint is called a synovial joint.

A synovial joint connects two bones with a fibrous joint capsule that is continuous with the periosteum or outer layer of both bones.

The fibrous capsule is lined with a synovial membrane that has cells that produce synovial fluid and remove debris.

The synovial fluid is normally a viscous fluid like the jelly-like part of a chicken egg and it helps lubricate the joint.

To help serve these synovial cells, the synovial membrane also has blood vessels and lymphatics running through it.

Together, the synovial membrane and the articular cartilage form the inner lining of the joint space.

Rheumatoid arthritis is an autoimmune process that is typically triggered by an interaction between a genetic factor and the environment.

For example, a person with a certain gene for an immune protein like human leukocyte antigen, or HLA- DR1 and HLA–DR4, might develop rheumatoid arthritis after getting exposed to something in the environment like cigarette smoke or a specific pathogen like a bacteria that lives in the intestines.

These environmental factors can cause modification of our own antigens, such as IgG antibodies or other proteins like type II collagen or vimentin.

Τype II collagen and vimentin can get modified through a process called citrullination.


Rheumatoid arthritis (RA) is a systemic inflammatory disorder of autoimmune origin that is primarily characterized by progressive, symmetric joint destruction, especially in the wrists and fingers, but may also affect other joints and many organs, such as the skin, heart, blood vessels, and lungs. Symptoms of RA include fatigue, joint pain, stiffness, and swelling, which can lead to decreased range of motion and joint deformity. RA is a chronic condition and treatment is focused on managing symptoms and preventing further joint damage. Treatment options include medications such as non-steroidal anti-inflammatory drugs (NSAIDs), disease-modifying antirheumatic drugs (DMARDs) and biologic agents, physical therapy, and in some cases, surgery.


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