What is the treatment for a wound infection after Anterior Cruciate Ligament (ACL) reconstruction on the knee?

Treatment for Wound Infection After ACL Reconstruction

The treatment for wound infection after ACL reconstruction requires immediate arthroscopic debridement and irrigation combined with appropriate antibiotic therapy, with the goal of eradicating infection while preserving the graft whenever possible. 1, 2

Diagnosis of Post-ACL Reconstruction Infection

• Monitor patient's temperature regularly (morning and afternoon) to detect early signs of infection 2
• Look for clinical signs:
  • Pain beyond expected post-surgical pain
  • Excessive swelling
  • Erythema
  • Warmth
  • Drainage from surgical site
• Laboratory evaluation:
  • Elevated erythrocyte sedimentation rate (ESR) - average 67 mm/hr 1
  • Elevated C-reactive protein (CRP) - average 14 mg/L 1
  • Elevated intra-articular white blood cell count - average 52,000 cells/μL 1

Treatment Algorithm

Step 1: Immediate Surgical Intervention

• Arthroscopic debridement and thorough irrigation (approximately 10 liters) of all knee compartments 3
• Obtain multiple tissue biopsies for microbiological analysis during surgery 3
• Insert through drainage system 2

Step 2: Antibiotic Therapy

• Start broad-spectrum antibiotic therapy immediately after obtaining cultures 3
• Initial recommendation: Systemic cefazolin or clindamycin (if penicillin allergic) 4, 5
• For more severe infections (Type III open wounds), add gram-negative coverage 4
• Adjust antibiotics based on culture and sensitivity results 3
• Duration: 14-42 days of intravenous antibiotics 1

Step 3: Graft Management Decision

• Assess graft integrity during arthroscopy 6
• If no intra-articular involvement and graft is intact: preserve the graft 2, 6
• If poor clinical response, graft insufficiency, or persistent infection: consider graft removal 3

Step 4: Additional Interventions Based on Severity

• For mild infections (Gächter stage I-II): arthroscopic debridement and irrigation 3
• For moderate infections (Gächter stage III): complete arthroscopic synovectomy 3
• For severe infections (Gächter stage IV) with osteolysis: open arthrotomy with debridement 3
• Average number of debridement procedures needed: 2.4 1

Step 5: Hardware Management

• If hardware (screws, buttons) is the source of infection: remove affected hardware 6
• If tunnels are affected: debride bone tunnels 3

Expected Outcomes

• Infection eradication rate is high with proper treatment 2
• Graft retention is possible in most cases (10 of 11 patients in one study) 1
• Average Lysholm functional knee score after infection: 71.6 out of 100 points 1
• Most common residual complaints: pain and stiffness 1

Important Considerations

• Hamstring autografts may have higher infection risk compared to other graft types 1
• Previous knee surgery, especially prior ACL reconstruction, increases infection risk 1
• Tibial ACL graft fixation with post and washer may be associated with higher infection rates 1
• Monitor for recurrent infection, which can occur even years after initial treatment 6
• Negative pressure wound therapy may be beneficial after closed fracture fixation but shows no advantage for open fractures 4

Prevention of Future Infections

• Immediate knee mobilization and strength/neuromuscular training should be implemented after successful infection treatment 4, 7
• Avoid continuous passive motion and functional bracing as they are not recommended by high-quality guidelines 4, 7

The key to successful management is early diagnosis, prompt surgical debridement, appropriate antibiotic therapy, and careful decision-making regarding graft preservation. With this approach, most patients can achieve infection eradication with preserved knee function.