Osteomyelitis Caused by Ralstonia mannitolilytica, a Rare Opportunistic Pathogen.

Ralstonia spp. are non-fermenting aerobic gram-negative rods found in humid environments, whose role as opportunistic human pathogens has lately been recognized. Ralstonia mannitolilytica is one of the three members of the Ralstonia genus (together with Ralstonia pickettii and Ralstonia insidiosa). Bone infections by Ralstonia spp. are very rare. We report a case of femoral osteomyelitis caused by R. mannitolilytica. Among literature search, only eight cases of bone infection due to the Ralstonia genus have been described, in all of which the causative agent was identified as R. pickettii. To our knowledge, this is the first reported case of osteomyelitis attributed to R. mannitolilytica. Despite its low virulence, Ralstonia has specific characteristics that promote its spread and shows high antibiotic resistance, partly due to its ability to create a biofilm. Identification of Ralstonia spp. poses unique difficulties as the distinction between the species of the genus is not straightforward. Additionally, the bacteria may be misidentified as other closely related species. Recent data suggests that modern spectrometry and gene sequencing techniques are essential to avoid these pitfalls. Susceptibility data about the genus is limited and based on a small number of case reports, therefore there is no standardized antibiotic susceptibility testing and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints exist. The report aims is to provide useful information on the antibiotic selection and treatment suggestions to be followed for bone infections caused by the Ralstonia genus, along with a review on the literature of this emerging opportunistic pathogen.

Distraction over nail using circular external fixation for septic pseudarthrosis of the tibia.

We present a report of nine patients (eight women and one man; mean age 37 years) from 2010 to 2012 with septic pseudarthrosis of the tibia treated with bone transport over an intramedullary nail using a circular external fixator. The mean follow-up was 15 months (range: 10-21 months). A two stage approach was used. At the first stage, removal of the primary osteosynthesis and extensive bone debridement to healthy, bleeding bone margins was performed. The bone defect was packed with antibiotic loaded cement beads, and stabilization of the tibia was done with a unilateral external fixator or with a long leg posterior splint. The mean size of bone defect was 4 cm (range: 3.5-5.5 cm). At the second stage, two consecutive negative wound cultures and normal values of blood cell count, C-reactive protein (CRP), and estimated sedimentation rate (ESR) were obtained. Then we reamed and locked the intramedullary nailing of the tibia, applied a circular external fixator, and performed percutaneous corticotomy of the tibia opposite the site of the bone defect. Bone distraction over the nail was initiated at the eighth postoperative day at a rate of 1 mm/day. At the last follow-up, union was achieved in all cases without recurrence of bone infection. All patients experienced excellent (n=3) or good (n=6) knee and ankle function, as well as complete return to their daily activities. Two patients experienced pin-tract infection, and one patient experienced anterior knee pain at the entry point of the nail.

Biplane fracture of the distal humeral lateral column: a report of two cases.

Articular fractures of the distal part of the humerus represent a challenging therapeutic problem, because they require thorough understanding of the complex local anatomy, extensile approaches, and reduction and fixation of small fragments that mainly consist of subchondral bone and articular cartilage. This report presents two cases of a unique fracture pattern of the lateral humeral column with a fracture line in the coronal plane separating the capitellum with a substantial portion of the lateral trochlear ridge, and with a second fracture line in the sagittal plane separating the residual, posterior portion of the lateral column, almost through the level of the capitellotrochlear sulcus, thus creating concomitant but distinct "low" lateral column and capitellum fractures. The radiographic findings that would suggest to the orthopaedic surgeon the possibility of this fracture pattern, the surgical approach that provides access to this complex articular fracture, and the fixation method are described.