Clinical Assessment

Investigations

1. Clinical examination — assess fluctuance, transillumination (ganglion cysts transilluminate), tenderness, range of motion
2. Ultrasound (first-line imaging) — differentiates bursitis (simple fluid) from ganglion (thick mucin) from solid lesion; guides aspiration
3. X-ray ankle — to exclude bony spur (a heel/malleolar spur can cause adjacent bursitis), fracture, or calcification
4. Bursal fluid analysis if aspirated — cell count, crystals (gout/CPPD), culture if septic bursitis suspected
5. Consider MRI if diagnosis is unclear or there is concern for tendon pathology

Treatment Plan

Step 1 — Conservative (First-line)

• Rest and activity modification — reduce friction from footwear; avoid tight shoes
• NSAIDs — e.g., Ibuprofen 400–600 mg TID with food for 7–14 days, or Naproxen 500 mg BD (if no contraindications)
• Ice packs — 15–20 minutes 3× daily to reduce inflammation
• Padding/footwear modification — doughnut-shaped padding around the malleolus to offload pressure
• Compression bandaging — helps prevent re-accumulation of fluid

Step 2 — Aspiration (if tense/painful or no improvement in 2–4 weeks)

• Diagnostic + therapeutic aspiration under sterile technique
  • For bursitis: clear/straw-coloured fluid expected; send for MC&S and crystal analysis
  • For ganglion cyst: thick honey-like mucin — may require larger bore needle (18G)
• Compression dressing post-aspiration to prevent recurrence
• If fluid is cloudy/purulent → septic bursitis — send cultures and start antibiotics (see below)

Step 3 — Corticosteroid Injection (if non-septic, inflammatory)

• After confirming non-infective bursitis: inject methylprednisolone 20–40 mg + 1% lignocaine 1 mL into bursal cavity at time of aspiration
• Evidence: A systematic review found corticosteroid injection in olecranon bursitis does not increase infection risk vs no injection; however RCT data show no major difference between aspiration alone vs aspiration + steroid vs NSAIDs alone — so start without injection first (Rosen's Emergency Medicine, p. 2356)

⚠️ Avoid steroid injection in superficial bursae without first excluding infection — complications include skin atrophy, persistent pain, and secondary septic bursitis.

Step 4 — Surgical Referral (if recurrent/persistent)

• Refer to orthopaedics if:
  • Recurrence after 2–3 aspirations
  • Underlying bony spur identified on X-ray
  • Suspected ganglion with joint communication or tendon involvement
  • Diagnosis remains uncertain (rare: malignant lesion can mimic ganglion/bursa)
• Surgical options: excision under regional or GA (higher cure rate for ganglion vs aspiration)

Red Flags — Exclude Septic Bursitis

• If septic bursitis confirmed: oral flucloxacillin 500 mg QID × 10 days (MSSA coverage) or co-amoxiclav
• IV antibiotics + inpatient admission if: diabetic, immunocompromised, systemic toxicity, or purulent drainage

Summary

1. Start with footwear modification, NSAIDs, and ice
2. Arrange ankle ultrasound to confirm diagnosis
3. If persistent or tense → aspiration ± corticosteroid injection (after excluding infection)
4. Refer to orthopaedics if recurrent or ganglion with structural involvement