Surgery

Surgery should be postponed until there are significant symptoms combined with clear evidence of a sequestrum.

Sulphan blue is injected preoperatively; this stains all vital tissue green, leaving dead tissue unstained. Under antibiotic cover, the surgeon removes all dead i.e. unstained - tissues and bone.

There are several strategies to prevent reinfection and promote healing:

• double lumen tubes are left in the lumen and antibiotic solution is introduced and aspirated 4 hourly; this is continued until the aspirate is sterile (3-6 weeks) and then the tube is gradually removed
• the cavity may be packed with gentamicin beads
• the cavity may be packed with multiple small bone grafts
• a muscle flap with an intact blood supply may be laid into the cavity

Note - surgery in a patient with chronic osteomyelitis is complex and often warrants technical expertise and multidisciplinary input. In general, operative principles include:

• Thorough debridement and excision of all infected tissue.
• Meticulous microbiological and histological sampling early during the procedure.
  • Obtaining uncontaminated representative samples to diagnose the causative organism and rule out other potential differentials, such as tumour, is essential.
• Dead space management to prevent the formation of haematoma.
  • Haematoma increases infection recurrence rates.
• Stabilisation of the bone, when there is instability or risk of fracture, usually with an external fixator.
• Attaining immediate soft-tissue coverage with healthy vascularised tissue that can deliver systemic antibiotics.

A 2-week course of antibiotics postoperatively is sufficient to allow for the treatment of any residual tissue infection and wound healing of the surgical site.

Reference

1. Schmitt SK. Osteomyelitis. Infect Dis Clin North Am. 2017 Jun;31(2):325-338.