What causes bursitis?

Causes of Bursitis

Bursitis is primarily caused by repetitive mechanical stress, trauma, infection, or inflammatory conditions that lead to inflammation of the bursal sac.

Primary Causes of Bursitis

Mechanical/Traumatic Causes

• Chronic microtrauma: Most common cause of superficial bursitis, particularly in the olecranon and prepatellar bursae 1
• Direct trauma: Acute injury to the bursa causing inflammation and potential hemorrhage 1
• Repetitive pressure: Prolonged kneeling, leaning on elbows, or repetitive motions 1
• Overuse: Excessive activity involving the affected joint, particularly in athletes 2
• Anatomical abnormalities: Bony prominences or structural variations that increase friction 2

Infectious Causes (Septic Bursitis)

• Direct inoculation: Through puncture wounds, open injuries, or surgical incisions 3
• Staphylococcus aureus: Most common pathogen in septic bursitis 1, 4
• Spread from adjacent infection: Cellulitis or other soft tissue infections 3
• Iatrogenic: Following bursal aspiration or injection procedures 1

Inflammatory/Systemic Causes

• Crystal deposition: Gout and calcium pyrophosphate deposition disease 1, 3
• Rheumatoid arthritis: Inflammatory arthritis affecting bursal tissues 1
• Other inflammatory conditions: Systemic inflammatory disorders 1

Location-Specific Bursitis

Greater Trochanteric Bursitis

• Biomechanical factors: Altered gait mechanics or leg length discrepancy 5
• Associated conditions: Often coexists with gluteus medius tendinosis 5
• Haglund's deformity: Posterior lateral prominence of the calcaneus causing retrocalcaneal bursitis 3

Olecranon Bursitis

• Occupational factors: Jobs requiring leaning on elbows 4
• Trauma: Direct impact to the posterior elbow 4
• Infection: One-third of olecranon bursitis cases are septic 4

Prepatellar Bursitis

• Occupational kneeling: Common in carpet layers, roofers, and gardeners 1
• Direct trauma: Falls or impacts directly to the knee 1

Risk Factors and Contributing Factors

• Age: More common in middle-aged and older adults 6
• Occupational activities: Jobs requiring repetitive motions or pressure on specific joints 7
• Sports activities: Certain athletic activities that stress particular bursae 2
• Improper technique: Poor biomechanics during activities 2
• Inadequate warm-up: Before physical activities 2
• Obesity: Increased mechanical stress on weight-bearing joints 5
• Previous joint injury: Creating altered biomechanics 6

Diagnostic Considerations

• Clinical presentation: Localized pain, swelling, and tenderness over the affected bursa 1
• Imaging: Radiographs are recommended as first-line imaging to rule out other conditions 3, 5
• Ultrasound: Useful for detecting fluid collections and distinguishing bursitis from cellulitis 1
• MRI: Best imaging modality for assessing peritrochanteric structures and surrounding soft tissues 5
• Bursal aspiration: Essential when infection is suspected, with fluid examination including Gram stain, crystal analysis, and culture 1

Prevention Strategies

• Activity modification: Avoiding repetitive pressure on vulnerable areas 2
• Protective padding: For knees, elbows, and other pressure points during activities 7
• Proper technique: In sports and occupational activities 2
• Strengthening exercises: For supporting muscles around susceptible joints 5
• Ergonomic adjustments: In workplace and daily activities 2

Understanding the specific cause of bursitis is crucial for appropriate management and prevention of recurrence. Treatment approaches should address both the acute inflammation and the underlying causative factors.