Musculoskeletal Imaging Update: Current Applications of Advanced Imaging Techniques to Evaluate the Early and Long-Term Complications of Patients with Orthopedic Implants

Technical advances in imaging have increased their applicability to diagnosing conditions of the musculoskeletal system, especially in the postoperative setting, where traditionally metallic artifacts have hindered evaluation. Advances in computed tomography (CT), magnetic resonance (MR) imaging, ultrasound, and nuclear medicine have resulted in improved overall image quality. Specific modifications of imaging parameters, especially in CT and MRI, have improved the radiologist's ability to diagnose potential hardware complications such as loosening and osteolysis. Sonography can evaluate the periprosthetic soft tissues and enables both diagnostic information and therapeutic treatment at the same sitting. Lastly, diagnostic scintigraphic applications such as positron emission tomography (PET) have increased specificity in diagnosing potential infection in the arthroplasty setting. This review discusses some of the current applications of CT, MRI, ultrasound, and nuclear medicine in evaluating the postoperative orthopedic patient, concentrating on the appropriate imaging evaluation for the painful arthroplasty patient

Rare human skin infection with Corynebacterium ulcerans: transmission by a domestic cat

Corynebacterium ulcerans is mainly known for its ability to cause animal infections. Some strains of C. ulcerans produce diphtheria toxin, which can cause life-threatening cardiopathies and neuropathies in humans. Human cutaneous C. ulcerans infection is a very rare disease that mimics classical cutaneous diphtheria. We present a very rare case of a C. ulcerans skin infection caused by a non-diphtheria toxin-producing strain of C. ulcerans that resolved after 3 weeks of therapy with amoxicillin-clavulanate. A pet cat was the probable source of infection. The presence of C. ulcerans in the mouth of the cat was confirmed by 16S rRNA gene analysis and the API Coryne system. In cases of human infection with potentially toxigenic corynebacteria, it is important to determine the species and examine the isolate for diphtheria toxin production. If toxigenicity is present, diphtheria antitoxin should be administered immediately. Carriers and potential infectious sources of C. ulcerans include not only domestic livestock but also pet animals. For the primary prevention of disease caused by diphtheria toxin-producing corynebacteria, vaccination with diphtheria toxoid is recommended