Arthritis: Types and Epidemiology

• Arthritis is defined as acute or chronic joint inflammation, often with pain, inflammation, and bone deformity
• Joints enable movement and consists of bones, cartilage, the synovial membrane, ligaments, tendons and bursa

Epidemiology

• As of 2019, 528 million people were affected by osteoarthritis
• Osteoarthritis has increased by 113% since 1990
• As of 2024, 7.6% of the global population is affected by osteoarthritis
• 0.24% of the world's population has rheumatoid arthritis
• In the USA, the female to male ratio is 3:1 for rheumatoid arthritis
• 55.8 million people are affected by gout globally
• Gout increased by 22.5% since 1990
• Gout is 3.26 times higher in men
• 0.1% to 0.2% of the world population is affected by psoriatic arthritis
• Psoriatic arthritis affects 112 per 100,000 adults
• Juvenile Idiopathic Arthritis is common in 1-4 year old children
• Juvenile Idiopathic Arthritis affects 1.6 to 23 cases per 100,000 children
• The incidence rate for ankylosing spondylitis varies with region
• There are 16.7 cases of ankylosing spondylitis per 10,000 people in Asia
• Ankylosing spondylitis is more common in males
• Septic arthritis affects 2-6 cases per 100,000 people

Types and Etiology

• Osteoarthritis is a degenerative joint condition, commonly caused by mechanical stress like wear and tear, and affects weight bearing joints
• Risk factors for osteoarthritis are age, joint injury, and obesity
• Rheumatoid arthritis is an autoimmune inflammatory joint condition
• Rheumatoid arthritis primarily affects the synovium and commonly affects smaller joints in hands and feet
• In children, rheumatoid arthritis presents as juvenile idiopathic arthritis
• Risk factors for rheumatoid arthritis are age, genetics, obesity, gender, smoking, and infection
• Gout is inflammatory arthritis where there are urate crystals in joints due to excessive uric acid, commonly affecting the big toe
• Risk factors for Gout are family history, diet, obesity, gender, alcohol, and medication
• Psoriatic arthritis is linked to an autoimmune disease of the skin (Psoriasis), where genetic and environmental factors play a role and it can affect any joints, including the spine
• Risk factors for psoriatic arthritis are family history, age, and psoriasis
• Ankylosing spondylitis involves chronic inflammation of the spine and sacroiliac joints where HLA-B27 gene increases the risk
• Risk factors for ankylosing spondylitis are family history, age, gender, and other medical conditions
• Septic arthritis is a painful infection of the joints, commonly caused by Staphylococcus aureus
• Septic arthritis bacteria enter through the bloodstream, injury, or surgical incision
• Risk factors for septic arthritis are artificial joints, chronic joint conditions, weak immune systems and immunosuppressive medications

Pathophysiology

• Causes include mechanical stress, autoimmune disorders, uric acid deposition and infections
• Inflammatory cells and cytokines infiltrate the synovium, elevating the inflammation process
• Inflammation of the synovium causes dysfunction of chondrocytes, with metalloproteinases enzyme released causing collagen fibre break down
• Osteoclasts become hyperactivated causing bone destruction, and osteophytes start to develop at the joint margins
• Repeated inflammation and bone destruction cause structural deformities and cartilage degeneration narrows the synovial cavity

Clinical Manifestations

• Joint pain, joint stiffness, swelling, crepitus, limited range of motion and deformities
• Systemic fatigue, fever, and weight loss are also clinical manifestations

Complications

• Systemic pulmonary fibrosis, inflammatory heart diseases, Sjogren's syndrome, and vasculitis
• Joint deformities and loss of joint function
• Neurological carpal tunnel syndrome and cervical myelopathy

Diagnostic Evaluation

• History should be obtained on onset of signs and symptoms, Past medical history, family history, medication history and lifestyle
• Inspection and palpation, measurement of range of motion and functional assessment
• Laboratory tests include Erythrocyte sedimentation rate, C-reactive protein, Rheumatoid factor, Anti-cyclic citrullinated peptide, Joint fluid analysis(Arthrocentesis), Antinuclear antibody
• Electrodiagnostic testing: Nerve conduction tests and Genetic tests
• The imaging tests include: X-ray, Magnetic Resonance Imaging, Ultrasonography and Arthroscopy

Treatment and Management

• Surgical treatment consists of synovectomy, where the inflamed synovium is removed through open surgery or arthroscopy
• Arthroscopy, where specialized instruments and a camera is inserted into joints through a small incision and used to remove damaged cartilage, ligaments and cartilage pieces
• Joint resurfacing where the damaged part of the joint is replaced by an implant
• Arthrodesis or Fusion to join two or more bones together using rods and pins, to improve joint strength
• Total Joint Arthroplasty, where the surgeon replace damaged or arthritic joint with prosthesis

Pharmacological Management

• Disease modifying antirheumatic drugs are medications used in treating inflammatory arthritis like rheumatoid arthritis by slowing its progression.
• There are two types of DMARDs: Conventional and Biological
• Conventional DMARDs: Methotrexate-(7.5-15mg weekly) and Sulfasalazine-(500mg-1g per day)
• Biological DMARDs: Rituximab-(1000mg IV every two weeks) and Infliximab-(3 mg/kg IV at 0, 2, and 6 weeks, THEN q8Weeks thereafter)
• Corticosteroids and NSAIDs reduce inflammation and pain
• Allopurinol and febuxostat inhibits xanthine oxidase, reducing uric acid concentration
• Allopurinol:100mg daily and Febuxostat: 40-80mg daily

Nursing Management

• Rest and joint protection

• Pain management

• Gentle ROM (range of motion) exercises

• Provide assistive devices like walker

• Patient education on joint protection, medications and assistive devices

• Pre-operative and post operative care

• Researchers at the University of Queensland received $11.54 million for groundbreaking research in the treatment of rheumatoid arthritis

• The Department of Health and Aged Care in Australia stated that antigen-specific tolerising immunotherapy instructs the immune system to tolerate joint proteins and enable patients to be in remission after stopping treatment with conventional anti-rheumatic medicines