Pathologic fracture and hardware failure in Streptococcus anginosus femoral osteomyelitis: Case report

Introduction

Pathologic fracture of the femur due to Streptococcus anginosus osteomyelitis has rarely been described. With limited evidence for treating S. anginosus osteomyelitis, the orthopaedic surgeon is presented with a difficult treatment decision at index presentation. Presented here is a case of failed conservative management, diagnostic dilemma, failed hardware stabilization, and definitive surgical treatment resulting in good clinical outcome.

Case presentation

A 69-year-old male experienced acute right thigh pain, edema, and erythema after dental treatment 17 days prior. He was diagnosed with right femoral diaphyseal osteomyelitis and Brodie's abscess. Blood cultures grew S. anginosus, but all site-specific tissue cultures resulted negative. Initial management consisted of intravenous antibiotic therapy and percutaneous abscess drainage. Months later, the patient sustained a displaced pathologic fracture of the diaphyseal femur and there was concern for neoplasm, but biopsies were negative. Stabilization was attempted with a lateral plate and screws. This hardware catastrophically failed in the setting of an oligotrophic femoral nonunion. Ultimately, the patient was successfully treated with an intramedullary nail coated with antibiotic-impregnated cement. Twelve months later, the patient achieved clinical and radiographic healing with no evidence of relapse of his osteomyelitis.

Clinical discussion

Conservative management of S. anginosus femoral osteomyelitis was inadequate and corroborates the existing literature. S. anginosus osteomyelitis and pyomyositis may be most optimally treated aggressively with early surgical intervention.

Conclusion

Early surgical debridement and stabilization of the compromised bone with an antibiotic coated intramedullary nail following medullary reaming may prevent pathologic fracture, eradicate infection, and achieve predictable outcomes.

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S. anginosus femoral osteomyelitis is rare and difficult to diagnose and treat.

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Conservative measures failed, and pathologic fracture later ensued.

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Although sparse, existing reports suggest early surgical management is indicated.

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This report provides more evidence for early and aggressive surgical management.

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Good outcome was achieved with antibiotic coated intramedullary nailing.