Chapter 10 - Imaging of Musculoskeletal Infections Related to Recreational Drug Use

Abstract

Soft tissue infections are pervasive throughout all subspecialties and can complicate diagnosis and treatment. Understanding and effectively treating the progression of soft tissue infections can become complicated, especially with direct inoculation of bacteria to otherwise isolated and rare sites. Drug use predisposes a patient to infections that can cause havoc if not recognized promptly. Critical radiographic elements can assist a clinician in the diagnosis and provide clues as to a possible etiology and associated microbiome. Imaging evaluation of musculoskeletal infections in recreational drug use is usually performed using radiographs, which are frequently nonspecific but may guide early treatment and can be used for subsequent monitoring of treatment algorithms. Magnetic resonance imaging (MRI) is often the imaging modality of choice for evaluating musculoskeletal infections, manifesting as increased T2 signal, correspondingly low T1 signal, and enhancement with intravenous (IV) contrast. IV drug use is a critical historical component when considering a differential diagnosis for crepitus and eschar of the skin. Early recognition of fascial edema and interfacial fluid on MRI in necrotizing fasciitis is essential. These signs are detected before soft tissue gas and will facilitate prompt treatment and dramatically impact prognosis. Prompt diagnosis of osteomyelitis is critical to the initial early administration of antibiotics to prevent osteonecrosis, which leads to significant long-term pain and disability. Imaging can assist in diagnosis and help determine treatment efficacy.