Osteomyelitis and Osteoarthritis Quiz

Osteoporosis

• Decrease in bone mass per unit of bone volume
• Metabolic bone disease
• Bone's normal ratio of mineral to matrix remains unchanged
• Primary and secondary types

Primary Osteoporosis

• Most common type
• Etiology is uncertain
• Common in postmenopausal women and elderly people
• Factors that contribute to primary osteoporosis:
  • Genetic factors: peak bone mass genetics
  • Estrogen: decline in estrogen levels
  • Aging
  • Calcium intake: less than 800mg/day
  • Exercise: lack of exercise
  • Environmental factors: smoking reduces estrogen levels

Osteopenia

• Decrease in cortical thickness
• Reduction in trabeculae size and number
• Fractures may be the first sign
• Compression fractures of vertebrae are common

Secondary Osteoporosis

• Corticosteroids:
  • Inhibits osteoblastic activity
  • Impairs Vitamin D absorption
• Hematologic malignancies (cancers of blood and blood-forming organs)
• Malabsorption:
  • Gastrointestinal diseases
  • Liver diseases
• Alcoholism:
  • Inhibits osteoblasts
  • Decreases calcium absorption

Osteomalacia and Rickets

• Inadequate mineralization of newly formed bone matrix (osteomalacia)
• Rickets: affects children with open epiphyseal plates, also a problem with cartilage
• Signs and Symptoms:
  • Beading of the costochondral junctions
  • Pectus carinatum (protruding breastbone)
  • Irregularities in teeth
• Causes:
  • Vitamin D deficiency
  • Phosphate deficiency
  • Defects in the mineralization process

Osteomalacia and Rickets: Pathological Findings

• Osteopenia
• Increased osteoid seams
• Pain that is poorly localized
• Common sites of pain: femoral neck, pubic ramus, spine, ribs

Hyperparathyroidism

• Caused by:
  • Parathyroid adenoma
  • Parathyroid hyperplasia
  • Parathyroid malignancy (rare)
• Parathyroid hormone:
  • Promotes phosphate excretion in urine
  • Stimulates osteoclastic activity, resulting in hypercalcemia (high blood calcium)
  • Stimulates tubular reabsorption of calcium and excretion of phosphate
  • Stimulates intestinal calcium absorption

Hyperparathyroidism: Signs and Symptoms

• Kidney stones (renal calculi)
• Bones: Brown tumors
• Psychiatric depression
• Gastrointestinal tract irregularities

Secondary hyperparathyroidism

• Also known as renal osteodystrophy
• Cause: Chronic renal failure
• Complications:
  • Decreased filtration of phosphate leads to hyperphosphatemia (high blood phosphate)
  • Reduced production of active vitamin D
  • Reduced calcium absorption in the gastrointestinal tract leading to hypocalcemia (low blood calcium)
  • Secondary hyperparathyroidism (increased parathyroid hormone)

Osteomyelitis

• Inflammation of bone caused by infectious organisms
• Common organisms involved:
  • Staphylococcus
  • Streptococcus
  • Escherichia coli
  • Neisseria gonorrhea
  • Haemophilus influenza
  • Salmonella
• Routes of Infection:
  • Direct penetration of wounds, fractures, surgery
  • Hematogenous (through bloodstream)
    • Teeth
    • Metaphyses (ends of long bones)
    • Knee, ankle, hip

Complications of Osteomyelitis

• Septicemia (blood poisoning)
• Acute bacterial arthritis
• Pathological fractures
• Squamous cell carcinoma
• Amyloidosis
• Chronic osteomyelitis

Arthritis - Introduction

• Inflammation of joints
• Common site for autoimmune injury:
  • Heart valves and joints are susceptible to damage
  • Hidden antigens are exposed by the damage
  • Infections, Degeneration (age, stress, lifestyle)

Arthritis - Clinical Features

• Pain: inflammation of the capsule, synovium, periosteum
• Swelling: inflammation, effusion (fluid buildup), proliferation
• Restricted movement: pain, fluid (effusion), synovial swelling, damage
• Deformity: mal-alignment, erosion, ankylosis (stiffening)

Osteoarthritis (OA)

• Most common joint disease
• Slow, degenerative disease that involves articular cartilage
• Weight-bearing joints are commonly affected
• Fingers are commonly involved
• Types:
  • Primary: Defect in cartilage, not inflammatory in nature
  • Secondary: Trauma, crystal deposits, infection
• Commonly affected joints:
  • Interphalangeal joints
  • Knees
  • Hips
  • Cervical and lumbar spine

Osteoarthritis (OA): Pathological Features

• Narrowing of the joint space (loss of articular cartilage)
• Increased thickness of subchondral bone (eburnation)
• Subchondral bone cysts
• Osteophytes (bone spurs):
  • Commonly found in the fingers, distal interphalangeal joints (Heberden nodes)

Osteoarthritis (OA): Causes

• Primary: Unknown cause
• Secondary:
  • Intraarticular fracture
  • Previous infective arthritis
  • Rheumatoid arthritis
  • Congenital dislocation of the hip
  • Abnormal stresses
    • Paget's disease
    • Chronic overuse
  • Metabolic and endocrine disorders
    • Hemochromatosis
    • Gout
    • Calcium phosphate deposition disease
  • Neuropathic disorders
    • Peripheral neuropathy as in diabetes mellitus
  • Excessive intraarticular corticosteroid injections

Osteoarthritis (OA): Summary

• Degenerative end result of aging
• Affects more than 80% of those over 65 years old
• Progressive erosion and fibrillation of the articular cartilage
• Large weight-bearing joints are commonly involved
• Hardened articular bone (eburnation)
• Subarticular cyst formation in bone
• Periarticular osteophyte formation
• Mild inflammation but painful
• Morning stiffness is common
• Limited range of motion
• Heberden nodes (osteophytes on the fingers)

Rheumatoid Arthritis (RA)

• Systemic, chronic, inflammatory disease
• Autoimmune disease
• Affects diarthrodial (synovial) joints bilaterally
• Begins as a synovial disease
• Affects women 3 times more than men
• Characterized by remissions and exacerbations
• Heredity and Epstein-Barr virus (EBV) are possible factors

Rheumatoid Arthritis (RA): Theory of Pathogenesis

• Genetically susceptible patient
• Infection (possible trigger)
• Formation of antibodies
• Antibodies act as new antigens
• Production of rheumatoid factor
• Deposits of immune complexes in the synovium (joint lining)
• Activation of the complement cascade
• Inflammation
• Activation of macrophages
• Influx of T cells
• Secretion of cytokines

Rheumatoid Arthritis (RA): Definition

• Chronic, multisystem, autoimmune inflammatory disorder that primarily affects the joints
• Produces a proliferative synovitis (inflammation of synovium)
• Progresses to destruction of the articular cartilage
• May lead to ankylosis (stiffening) of the joint

Rheumatoid Arthritis (RA): Etiology

• Genetic susceptibility
  • HLA-DR4 or DR1 present in 65% - 80% of cases
• Microbial inciting agents
  • Epstein-Barr virus, Borrelia, Mycoplasma
• Autoimmunity
  • IgM anti-IgG (rheumatoid factor)
  • Helper T cells (CD4) against type II collagen and cartilage glycoprotein-39

Rheumatoid Arthritis (RA): Pathology

• Inflammation of the joint and hyperplasia of the synovium
• Destruction of the articular structures
• Synovium infiltrated with lymphocytes, plasma cells, and macrophages
• Fibrin exudation (leakage) into the synovial fluid
• Formation of soft, loose bodies called Rice bodies
• Neutrophil polymorphs are present

Rheumatoid Arthritis (RA): Pathology - Reversibility

• Earlier changes are reversible
• When granulation tissue grows over the articular cartilage, it forms pannus
• Pannus interferes with cartilage nutrition, leading to permanent joint damage

Rheumatoid Arthritis (RA): Histopathological Features

• Rice bodies
• Hyperplastic synovium (overgrowth of joint lining)
• Pannus (inflamed granulation tissue)
• Allison-Ghormley bodies
• Rheumatoid nodules

Rheumatoid Arthritis (RA): Extra-articular Manifestations

• Rheumatoid nodules
• Vasculitis
• Cardiac disease
• Pulmonary disease
• Serosal inflammation
• Amyloidosis
• Anemia
• Eye involvement

Rheumatoid Arthritis (RA): Morphology

• Proliferative synovitis with lymphocytes (CD4), plasma cells and macrophages (pannus)
• Organizing fibrin (Rice bodies)
• Neutrophils on the joint surface and fluid
• Juxta-articular erosions, cysts, and osteoporosis
• Fibrous ankylosis (stiffening of joint)
• Skin: Rheumatoid nodules, vasculitis

Differentiating Features Between Rheumatoid Arthritis and Osteoarthritis

• Rheumatoid Arthritis
  • Affects younger individuals
  • Affects small joints
  • Primarily an autoimmune disease
  • Synovial inflammation occurs first, which then damages the cartilage
• Osteoarthritis
  • Affects older individuals
  • Affects large joints
  • Primarily a degenerative disease
  • Cartilage degeneration occurs first

Test your knowledge on conditions like osteomyelitis and osteoarthritis. This quiz covers essential concepts such as the causes, complications, and characteristics of these bone and joint diseases. Dive into specifics such as infectious organisms and arthritis types.