What is the treatment for an infected intramedullary nail with Staphylococcus epidermidis (S. epidermidis) and Candida?

Treatment of Infected Intramedullary Nail with Staphylococcus epidermidis and Candida

For an infected intramedullary nail with both S. epidermidis and Candida, remove the nail, perform thorough debridement, and treat with combination therapy: vancomycin for the S. epidermidis and fluconazole for the Candida, followed by definitive fixation once infection is eradicated.

Antimicrobial Selection

Antibacterial Coverage for S. epidermidis

• Vancomycin is the drug of choice for methicillin-resistant staphylococci including S. epidermidis, particularly in prosthetic/implant-related infections 1
• Vancomycin has documented effectiveness in combination therapy for early-onset prosthetic valve endocarditis caused by S. epidermidis, which shares similar biofilm-forming characteristics with infected intramedullary nails 1
• The typical approach involves intravenous vancomycin administration following surgical debridement 1

Antifungal Coverage for Candida

• Itraconazole demonstrates significantly greater efficacy than other agents for Candida nail infections, with cure rates of 92% in clinical studies 2
• The recommended dosing is 400 mg daily for 1 week per month (pulse therapy), repeated for 2-4 months depending on infection severity 2
• Fluconazole represents a reasonable alternative if itraconazole is contraindicated or not tolerated, though it appears less effective 2
• Fluconazole dosing for systemic Candida infections ranges from 200-400 mg daily, with higher doses used based on severity 3
• For mixed bacterial-fungal infections, fluconazole's once-daily dosing may improve compliance during prolonged treatment 4

Surgical Management Algorithm

Stage-Based Treatment Approach

The management strategy depends on timing of infection diagnosis and fracture union status 5:

For healed fractures/unions with infection:

• Perform debridement and nail removal 5, 6
• Administer systemic antibiotics (vancomycin) and antifungals (itraconazole or fluconazole) 5
• Success rate for infection eradication: 90% 6

For unhealed fractures/nonunions with infection:

• Remove the infected nail and perform thorough debridement 5, 6
• Consider antibiotic-impregnated cement rod insertion to fill dead space and provide temporary mechanical support 7
• The cement rod can be custom-made with vancomycin and antifungal agents embedded 7
• After 6 weeks and negative cultures, remove cement rod and insert definitive metal nail with bone grafting if needed 7
• Alternative: external fixation if extensive bone loss present 5, 6

Critical Management Principles

Debridement Requirements

• Thorough intramedullary canal debridement is mandatory before any definitive treatment 5, 6
• Reaming of the canal during exchange nailing helps remove infected tissue and biofilm 5
• All necrotic tissue and purulent material must be excised 6

Duration of Antimicrobial Therapy

• Continue systemic antibiotics and antifungals until canal cultures are negative 7
• Typical duration: 6 weeks minimum for deep bone infections 7
• For Candida component specifically, treatment should continue for at least 2 weeks following resolution of clinical signs 3
• Do not discontinue antibiotics until infection is fully eradicated to prevent recurrence 7

Common Pitfalls and How to Avoid Them

Inadequate Source Control

• Never rely on antibiotics alone without removing the infected hardware - the biofilm on the nail prevents adequate drug penetration 5, 6
• Retention of infected nail is associated with treatment failure and higher complication rates 6

Underestimating Candida Pathogenicity

• Candida in the setting of hardware infection is a true pathogen, not a colonizer 4, 8
• Mixed bacterial-fungal infections require treatment of both organisms simultaneously 4
• Failure to treat the fungal component will result in persistent infection despite appropriate antibacterial therapy 8

Premature Definitive Fixation

• Wait for documented negative cultures before inserting permanent hardware 7
• Rushing to definitive fixation before infection clearance leads to recurrence 7

Monitoring and Follow-up

• Obtain intramedullary canal cultures at time of cement rod removal or before definitive fixation 7
• All cultures must be negative before proceeding with permanent hardware 7
• Monitor for recurrence during 38-48 month follow-up period minimum 7
• No patient should require antibiotics after successful treatment completion 7