Moreover, 10.2% of laboratories wrongly reported serological evidence for active infection in samples from patients with past syphilis or in sera from seronegative blood donors. Consequently, the continuous participation of laboratories in proficiency testing and further standardization of tests is strongly recommended to achieve better quality of syphilis serology.

The purpose of our study was to investigate the antibacterial effect of a spacer (Ti6Al4V) coated with 4x Cu-TiO2 in an animal model simulating an acute periprosthetic infection by Staphylococcus aureus. Ti6Al4 bolts contaminated with Staphylococcus aureus were implanted into the femoral condyle of rabbits (n = 36) divided into 3 groups. After one week in group 1 (control) the bolts were removed without any replacement. In group2 Ti6Al4V bolts with a 4x Cu-TiO2 coating and in group 3 beads of a gentamicin-PMMA chain were imbedded into the borehole. Microbiological investigation was performed at the primary surgery, at the revision surgery and after scarification of the rabbits 3 weeks after the first surgery. Blood tests were conducted weekly. The initial overall infection rate was 88.9%. In group 2 and 3 a significant decrease of the infection rate was shown in contrast to the control group. The C-reactive protein (CRP) levels declined one week after the first surgery except in the control group where the CRP level even increased. This is the first in vivo study that demonstrated the antibacterial effects of a fourfold Cu-TiO2 coating. For the future, the coating investigated could be a promising option in the treatment of implant-associated infections.

A 68-year-old woman developed tenosynovitis of the right second digit without a history of injury or animal bites. Apart from high titer anti-nuclear antibodies, serological studies were unremarkable. Tuberculin test and interferon gamma release assay were both negative. Several immunosuppressive therapies led only to partial relief of symptoms. Of note, clinical symptoms worsened significantly after introduction of adalimumab therapy. Tenosynovectomy was performed revealing a granulomatous inflammatory process. Seven weeks later, Mycobacterium malmoense could be cultured from the surgical specimen. A four drug antibiotic regimen was started and immunosuppressive therapy discontinued resulting in complete clinical remission. Our case highlights non-tuberculous mycobacterial (NTM) tenosynovitis as an important differential diagnosis of atypical arthritis. A negative tuberculin skin test as well as negative Ziehl-Neelsen stain does not argue against NTM infection. In fact, mycobacterial culture for extended periods remains the gold standard for diagnosis.

Due to ease of practical handling and favorable pharmacoeconomics, this DDS is recommended for both open and minimally invasive surgery.