What factors might prompt further investigation for osteomyelitis in a patient with acute left lower leg cellulitis and a history of open reduction internal fixation (ORIF) surgery with retained hardware, showing possible increased sclerosis and new periosteal reaction on computed tomography (CT) scan?

From the Guidelines

The medical team should investigate further for osteomyelitis in this patient with acute left lower leg cellulitis given several concerning factors, including the presence of orthopedic hardware and CT findings suggestive of bone infection. The presence of a TTC nail from previous ankle surgery, multiple surgical revisions, and CT findings of increased sclerosis and periosteal reaction in adjacent bones are all red flags for potential bone infection 1. Additional factors that would prompt further investigation include persistent or recurrent soft tissue infection despite appropriate antibiotics, elevated inflammatory markers (ESR, CRP), fever or systemic symptoms, drainage from surgical sites, pain at the hardware site, and loosening of the implant. Some key points to consider in the investigation of osteomyelitis in this patient include:

• The use of MRI with contrast as the modality of choice in the evaluation of osteomyelitis, as recommended by the American College of Radiology 1
• The potential utility of labeled leukocyte scan and sulfur colloid marrow scan in evaluating active infection in the presence of orthopedic hardware 1
• The importance of bone biopsy for culture and histopathology in confirming the diagnosis of osteomyelitis
• The need for surgical consultation for possible hardware removal, as osteomyelitis associated with orthopedic hardware often requires a combination of surgical debridement and prolonged antibiotic therapy. Given the challenges of treating osteomyelitis associated with orthopedic hardware, early diagnosis is crucial to initiate appropriate management and prevent long-term complications.

From the Research

Factors Prompting Further Investigation for Osteomyelitis

The patient's history of ankle ORIF surgery and the presence of hardware in place, combined with the CT scan findings of possible increased sclerosis and new periosteal reaction in adjacent bones to the TTC nail, may prompt the medical team to investigate further for osteomyelitis. The following factors may contribute to this decision:

• History of surgical revisions, which may increase the risk of infection 2
• Presence of hardware in place, which can serve as a conduit for infection 3, 4
• Imaging findings suggestive of bone inflammation or infection, such as increased sclerosis and periosteal reaction 3, 4
• Clinical suspicion of osteomyelitis, which may be supported by laboratory results and physical examination findings 3, 4

Diagnostic Considerations

The diagnosis of osteomyelitis is typically made using a combination of imaging studies, laboratory tests, and clinical evaluation. The following diagnostic considerations may be relevant:

• Imaging studies, such as radiography, magnetic resonance imaging (MRI), and computed tomography (CT) scans, can help identify areas of bone inflammation or infection 3, 4
• Laboratory tests, such as blood cultures and bone biopsies, can help confirm the diagnosis of osteomyelitis and identify the causative organism 3, 4, 5
• Clinical evaluation, including physical examination and medical history, can help identify risk factors for osteomyelitis and guide diagnostic testing 3, 4

Risk Factors for Osteomyelitis

The patient's history and clinical presentation may suggest several risk factors for osteomyelitis, including:

• Presence of hardware in place, which can increase the risk of infection 3, 4
• History of surgical revisions, which may increase the risk of infection 2
• Diabetes mellitus and cardiovascular disease, which can increase the overall risk of acute and chronic osteomyelitis 4
• Presence of purulent fluid or other signs of infection, which can increase the likelihood of positive culture results 6