Anatomical study of all carpal and adjoining bones of the wrist using 3D CT reconstruction -Finding the ultimate biomechanical theory.

BACKGROUND: The complex interplay of single wrist bones acting in combination with their ligamentous connections is still not fully understood. In this regard various theories exist, divisible in columnar and ring/row theories. The object of this study was to examine the mobility of the individual carpal bones as well as the ulna and metacarpals relative to each other in wrists of cadaveric hands using CT scans. METHODS: The regular wrist mobility of a total of 21 cadaveric hands was examined by CT imaging in neutral position, radial/ulnar abduction as well as wrist flexion and extension. The data were evaluated as 3D models by using a standardized global coordinate system and object coordinate systems. Rotation and translation of each carpal bone as well as radius/ulna and all metacarpal bones were evaluated. RESULTS: The principal motion took place in the carpus between the radius and the proximal carpal row followed by the midcarpal joint and the carpometacarpal joints and not mainly between the individual bones of a row. The scaphoid moves out of its row aggregate mainly during flexion and adapts to the motion of the distal carpal row. The trapezium and first metacarpal bones play a specific role detached from the remaining bones. CONCLUSIONS: With this study, a better understanding of the motion of the individual bones of the carpus, the metacarpals and the radius/ulna is shown. The study supports the row theory, where most motion takes place between the individual rows and not between the carpal bones, leaving the scaphoid and the first ray in a special role between the rows.

Free Latissimus Dorsi Myocutaneous Flap in a 6-Month-Old Child for Reconstruction of a Temporal Fossa Defect After Teratoma Resection.

Although free flap reconstruction has already gained widespread acceptance in pediatric patients, little is known about the outcome of free tissue transfer in head and neck reconstruction in pediatric patients. We present a case of a 6-month-old boy with a large volume deficit in the right temporal fossa after resection of a teratoma. This led to a large volume deficit with widely undermined skin margins. Therefore, we provided volume augmentation by microsurgical free latissimus dorsi myocutaneous flap transplantation. Intraoperative use of laser-assisted indocyanine green angiography indicated excellent flap perfusion. Postoperative magnetic resonance imaging showed adequate flap perfusion with no signs of flap necrosis. To our best knowledge, this case presents the youngest patient who underwent free flap transplantation in the head and neck region. Our case demonstrates that microvascular surgery can play an important role in particular cases in pediatric oncology, even in very young patients.

Negative pressure wound treatment with computer-controlled irrigation/instillation decreases bacterial load in contaminated wounds and facilitates wound closure.

Microbial wound contamination is known to be a hindrance to wound healing. Negative pressure wound therapy (NPWT) with or without irrigation is known to optimise conditions in problem wounds. The aim of this study was to investigate the influence of computer-controlled wound irrigation with NPWT on the bacterial load in contaminated wounds. A total of 267 patients were treated with NPWT with automated instillation because of problematic wounds using an antiseptic instillation solution. In 111 patients, a minimum of 4 operative procedures were necessary, and swabs were taken at least at the first and at the fourth operation in a standardised procedure. The number of different bacteria and the amount of bacteria were analysed during the course. In a subgroup of 51 patients, swabs were taken at all 4 operative procedures and analysed separately. In an overall analysis, the number of different bacteria and the amount of bacteria significantly decreased independent of wound localisation and diagnosis. NPWT with automated instillation demonstrates a positive influence in the reduction of bacterial load in problem wounds. Thus, it may help to optimise wound conditions before definite wound closure.

Regulation of surface expression of TRPV2 channels in the retinal pigment epithelium.

PURPOSE: The retinal pigment epithelium (RPE) interacts closely with the photoreceptors in fulfilling tasks of visual function. Since an understanding of the RPE function is essential for understanding the patho-mechanisms involved in vision loss, we explored the regulation of the vanilloid receptor subtype transient receptor potential TRPV2 channels that trigger insulin-like growth factor-1 (IGF-1)-induced vascular endothelial growth factor A (VEGF-A) secretion. METHODS: Immunohistochemistry was used to assess TRPV2 expression in retinal cross-sections or ARPE-19 cells, and surface expression of TRPV2 was quantified using confocal microscopy. Membrane currents of ARPE-19 cells were recorded using a whole-cell configuration of the patch-clamp technique. RESULTS: TRPV2 expression was detected in the RPE of the mouse retina as well as in ARPE-19 cells. Increasing the temperature to 45 °C activated membrane conductance sensitive to SKF-96365 and ruthenium red in 60 % of cells. Preincubation with either cannabidiol (CBD) or IGF-1 led to a three- or fourfold increase in current density, respectively, in all cells, which was blocked by SKF-96365. In contrast to IGF-1, CBD stimulation of membrane conductance was further increased by heat. TRPV2 surface expression was increased by both IGF-1 and CBD, with the increase by CBD twice as large as that by IGF-1. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 abolished the effects on membrane conductance and surface expression. CONCLUSIONS: Both CBD and IGF-1 enhance TRPV2 channel activity by specific proportions of both channel activation and PI 3-kinase-dependent surface expression: IGF-1 predominantly increases ion channel activity, whereas CBD is more active in increasing TRPV2 surface expression. Thus, differential regulation of TRPV2 surface expression is an important mechanism for modulating the responsiveness of the RPE to growth factors.