Canibacter oris - a fairly unknown pathogenic agent of bite wound infections.

Here, we report on the second case of bite wound infection by Canibacter oris. This bacterium belongs to the family of Microbacteriaceae in the order of Microbacterales in the class of Actinobacteria, which are prevalent in the oral flora. Possibly this bacterium has been overlooked until now, because it cannot be recognized by conventional differentiation methods. MALDI-TOF as well as PCR are able to identify this pathogen.

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 mapping at 3T MRI of the wrist: Feasibility and clinical application.

PURPOSE: To assess the feasibility of delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) and T2 mapping for biochemical imaging of the wrist at 3T. MATERIALS AND METHODS: Seventeen patients with wrist pain (mean age, 41.4 ± 13.1 years) including a subgroup with chondromalacia (n = 11) and 15 healthy volunteers (26.0 ± 2.2 years) underwent dGEMRIC and T2 mapping at 3T. For dGEMRIC, the optimum time window after contrast-injection (gadopentetate dimeglumine) was defined as the plateau of the T1 curve of repeated measurements 15-90 minutes postinjection and assessed in all volunteers. Reference values of healthy-appearing cartilage from all individuals and values in areas of chondromalacia were assessed using region-of-interest analyses. Receiver-operating-characteristic analyses were applied to assess discriminatory ability between damaged and normal cartilage. RESULTS: The optimum time window was 45-90 minutes, and the 60-minute timepoint was subsequently used. In chondromalacia, dGEMRIC values were lower (551 ± 84 msec, P < 0.001), and T2 values higher (63.9 ± 17.7, P = 0.001) compared to healthy-appearing cartilage of the same patient. Areas under the curve did not significantly differ between dGEMRIC (0.91) and T2 mapping (0.99; P = 0.17). In healthy-appearing cartilage of volunteers and patients, mean dGEMRIC values were 731.3 ± 47.1 msec and 674.6 ± 72.1 msec (P = 0.01), and mean T2 values were 36.5 ± 5 msec and 41.1 ± 3.2 msec (P = 0.009), respectively. CONCLUSION: At 3T, dGEMRIC and T2 mapping are feasible for biochemical cartilage imaging of the wrist. Both techniques allow separation and biochemical assessment of thin opposing cartilage surfaces and can distinguish between healthy and damaged cartilage. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:381-389.

Force-controlled dynamic wear testing of total ankle replacements.

Currently, our knowledge of wear performance in total ankle replacements is limited. The aim of this study is to develop a scenario for force-controlled testing and wear testing of total ankle replacements. A force-controlled wear test was developed: based on cadaver measurements, the passive stabilization (ligaments and soft tissue) of the ankle joint was characterized and a restraint model for ankle stabilization was developed. Kinematics and kinetics acting at the replaced ankle joint were defined based on literature data and gait analysis. Afterwards, force-controlled wear testing was carried out on a mobile, three-component, total ankle replacement design. Wear was assessed gravimetrically and wear particles were analyzed. Wear testing resulted in a mean wear rate of 18.2±1.4mm(3)/10(6) cycles. Wear particles showed a mean size of 0.23µm with an aspect ratio of 1.61±0.96 and a roundness of 0.62±0.14. Wear testing of total ankle replacement shows that a relevant wear mass is generated with wear particles in a biologically relevant size range. The developed wear test provides a basis for future wear testing of total ankle replacements.

Cartilage imaging of the hand and wrist using 3-T MRI.

The prevalence of osteoarthritis of the hand and wrist is high, and a thorough assessment of even subtle cartilage injuries is necessary before surgical interventions. Although magnetic resonance imaging (MRI) has been established as an important diagnostic tool for the evaluation of hand and wrist disorders, the focus has been on the assessment of the triangular fibrocartilage complex, tendons, ligaments, and the detection of avascular necrosis or occult fractures rather than on cartilage imaging. 3-T MR systems have become more and more widely available and yield an improved signal-to-noise ratio and thus a higher spatial resolution than 1.5-T systems. In principle, this should be especially beneficial for depicting the thin cartilage layers of the hand and wrist. This review focuses on cartilage imaging of the hand and wrist with 3-T MRI and addresses these four topics: (1) the advantages of 3-T versus 1.5- and 1-T MRI, (2) dedicated sequence protocols at 3 T including novel three-dimensional sequences, (3) imaging findings in common cases of overuse or sports injury, and (4) functional cartilage imaging techniques of the hand and wrist, for instance, delayed gadolinium-enhanced MRI of the cartilage.