What are the possible causes and treatments for sudden onset of elbow swelling, warmth, and pain?

Sudden Onset of Elbow Swelling, Warmth, and Pain

The most critical first step is to rule out septic arthritis through immediate joint aspiration with culture and synovial fluid analysis, as this represents a medical emergency requiring urgent treatment to prevent permanent joint damage and systemic complications. 1

Immediate Diagnostic Priorities

Rule Out Septic Arthritis First

• Septic arthritis is the most urgent diagnosis to exclude because it requires immediate intervention to prevent irreversible joint destruction and potential sepsis 1
• Key clinical features include joint effusion with systemic signs of infection (fever, elevated inflammatory markers) 1
• Immediate arthrocentesis with culture is mandatory when septic arthritis is suspected, followed by empiric antibiotics and potential surgical debridement 1

Initial Imaging

• Plain radiographs are mandatory as first-line imaging to differentiate between infectious, inflammatory, traumatic, and neoplastic causes 2, 1
• Radiographs can identify:
  • Joint effusion (posterior and anterior fat pad elevation) 2
  • Fractures or dislocations 2
  • Intra-articular loose bodies 1
  • Heterotopic ossification 1
  • Tumors 1
  • Osteomyelitis (periosteal reaction, erosions, or bone sclerosis) 1

When Imaging Cannot Distinguish Infection

• Image-guided aspiration is essential when imaging cannot differentiate infected from noninfected fluid collections 1
• Culture identifies the organism and directly affects treatment decisions 1
• CT with IV contrast can assess soft tissue extent and differentiate cellulitis, myositis, tenosynovitis, and abscess from septic arthritis 1

Differential Diagnosis Based on Clinical Presentation

Infectious Causes (Highest Priority)

• Septic arthritis: Intra-articular infection with systemic signs 1
• Soft tissue infection/cellulitis: Effacement of fat planes and soft tissue swelling without intra-articular involvement 1
• Olecranon bursitis (septic): Common cause of posterior elbow pain and swelling, diagnosed by bursal fluid analysis 3

Inflammatory Causes

• Olecranon bursitis (aseptic): Posterior swelling without infection 3
• Elbow arthritis: Can cause pain, swelling, and stiffness; most common etiologies include rheumatoid arthritis, posttraumatic arthritis, and primary osteoarthritis 4

Traumatic Causes

• Fractures: Most commonly radial head/neck (50% of adult elbow fractures) 2
• Ligamentous injuries: Ulnar collateral ligament or lateral collateral complex injuries 1
• Tendon injuries: Biceps or triceps tendon tears 2

Treatment Algorithm

For Septic Arthritis (Medical Emergency)

1. Immediate arthrocentesis with culture 1
2. Empiric antibiotics started immediately after culture obtained 1
3. Surgical debridement if indicated 1

For Inflammatory/Aseptic Conditions

1. NSAIDs for pain relief along with rest and activity modification 1, 5
2. Cryotherapy (ice application) for 10-minute periods in acute phase for pain relief 6, 5
3. Corticosteroid injections may be used for persistent symptoms despite first-line treatment, but use with caution due to potential complications including tendon weakening 1, 6

For Traumatic Injuries

1. Compression wrap and semirigid supports for initial management 1
2. Progressive strengthening exercises once acute phase resolves 1
3. Surgical consultation for refractory cases or unstable fractures 1

For Olecranon Bursitis

• Diagnosis based on history, physical examination, and bursal fluid analysis if necessary 3
• Treatment depends on whether septic or aseptic 3

Advanced Imaging When Initial Workup Is Inconclusive

MRI Indications

• MRI without IV contrast is appropriate for evaluating ligamentous injuries (UCL, lateral collateral complex) and tendinous pathology 1
• MRI or MR arthrography for loose bodies, osteochondral lesion stability, and synovial abnormalities 1
• MRI should not be used as initial imaging but reserved for when radiographs are normal or indeterminate 2

CT Indications

• CT without IV contrast for clarification of fracture morphology when radiographs are equivocal 2
• CT with IV contrast to assess soft tissue extent and differentiate various soft tissue pathologies 1

Critical Pitfalls to Avoid

• Never delay aspiration when septic arthritis is suspected—this is a time-sensitive emergency that can result in permanent joint destruction 1
• Do not rely solely on imaging to exclude infection; aspiration with culture is definitive 1
• Avoid overuse of corticosteroid injections as they may inhibit healing and reduce tendon tensile strength, potentially causing spontaneous rupture 6
• Do not order advanced imaging (MRI, CT) as first-line studies—plain radiographs are mandatory initially 2, 1