Description

• Bursae are synovial fluid-filled sacs found in areas subject to musculoskeletal friction, such as when tendons pass over bony prominences.
• Although there are at least 78 different sites where bursae are found, the most common sites of clinical bursitis are the following:
  • Subdeltoid/subacromial
  • Olecranon (“student’s elbow”)
  • Prepatellar (“housemaid’s knee”)
  • Infrapatellar (“clergyman’s knee”)
  • Trochanteric
  • Radiohumeral
  • Ischial (“weaver’s bottom”)
  • Pes anserinus
  • Retrocalcaneal
• Bursae serve a lubricating function, allowing for musculotendinous units to glide over bony prominences.
• Bursae are lined with synovial membrane and play a role in synovial fluid mechanics.
• System(s) affected: musculoskeletal

Pediatric Considerations
Bursitis is less common in children.

Epidemiology

Predominant age

• 15 to 50 years (most common in skeletally mature)
• Traumatic bursitis is more likely in patients <35 years of age.

Incidence

• Bursitis: 32/1,000 per year
• Approximately 1 in 31; 3.2% or 8.7 million people in the United States impacted annually.
• Trochanteric pain: 1.8/1,000 per year

Etiology and Pathophysiology

• Trauma: acute or chronic
• Repetitive movement: Upper extremity bursitis, in particular, is usually the result of repetitive microtrauma.
• Infections: transcutaneous transit > hematogenous, most commonly Staphylococcus aureus
• Systemic disease: rheumatoid disease, tuberculosis, pancreatitis, lupus
• Crystal deposition: gout and pseudogout

Risk Factors

• Individuals who engage in repetitive motion and/or vigorous training
• Prolonged pressure on particular bursae (e.g., “clergyman’s knee” and “student’s elbow”)
• Sudden increase in level of activity
• Leg length discrepancy and Trendelenburg gait increase risk for trochanteric bursitis.
• Anabolic steroid use increases risk of bursitis due to increased training, estrogen suppression causing increased inflammation, and muscle stiffness.

General Prevention

• Appropriate warm-up and cool-down maneuvers
• Frequent breaks between repetitive activities
• Use of protective gear (e.g., knee and elbow pads)
• Maintain fitness and general health.

Commonly Associated Conditions

• Tendinitis
• Sprains, strains
• Associated stress fractures
• Muscular tightness and physical deconditioning