2D-fluoroscopic navigated percutaneous screw fixation of pelvic ring injuries - a case series

<p>Abstract</p> <p>Background</p> <p>Screw fixation of pelvic ring fractures is a common, but demanding procedure and navigation techniques were introduced to increase the precision of screw placement. The purpose of this case series was the evaluation of screw misplacement rate and functional outcome of percutaneous screw fixation of pelvic ring disruptions using a 2D navigation system.</p> <p>Methods</p> <p>Between August 2004 and December 2007, 44 of 442 patients with pelvic injuries were included for closed reduction and percutaneous screw fixation of disrupted pelvic ring lesions using an optoelectronic 2D-fluoroscopic based navigation system. Operating and fluoroscopy time were measured, as well as peri- and postoperative complications documented. Screw position was assessed by postoperative CT scans. Quality of live was evaluated by SF 36-questionnaire in 40 of 44 patients at mean follow up 15.5 ± 1.2 month.</p> <p>Results</p> <p>56 iliosacral- and 29 ramus pubic-screws were inserted (mean operation time per screw 62 ± 4 minutes, mean fluoroscopy time per screw 123 ± 12 seconds). In post-operative CT-scans the screw position was assessed and graded as follows: I. secure positioning, completely in the cancellous bone (80%); II. secure positioning, but contacting cortical bone structures (14%); III. malplaced positioning, penetrating the cortical bone (6%). The malplacements predominantly occurred in bilateral overlapping screw fixation. No wound infection or iatrogenic neurovascular damage were observed. Four re-operations were performed, two of them due to implant-misplacement and two of them due to implant-failure.</p> <p>Conclusion</p> <p>2D-fluoroscopic navigation is a safe tool providing high accuracy of percutaneous screw placement for pelvic ring fractures, but in cases of a bilateral iliosacral screw fixation an increased risk for screw misplacement was observed. If additional ramus pubic screw fixations are performed, the retrograde inserted screws have to pass the iliopubic eminence to prevent an axial screw loosening.</p

Navigated cup implantation in hip arthroplasty: A meta-analysis

Background and purpose Many studies have suggested that navigation-based implantation can improve cup positioning in total hip arthroplasty (THA). We conducted a systematic review and meta-analysis to compile the best available evidence, and to overcome potential shortcomings because of small sample sizes in individual studies

Comparative mapping of Xp22 genes in hominoids - Evolutionary linear instability of their Y homologues

Several genes located within or proximal to the human PAR in Xp22 have homologues on the Y chromosome and escape, or partly escape, inactivation. To study the evolution of Xp22 genes and their Y homologues, we applied multicolour fluorescence in situ hybridization (FISH) to comparatively map DNA probes for the genes ANT3, XG, ARSD, ARSE (CDPX), PRK, STS, KAL and AMEL to prometaphase chromosomes of the human species and hominoid apes. We demonstrate that the genes residing proximal to the PAR have a highly conserved order on the higher primate X chromosomes but show considerable rearrangements on the Y chromosomes of hominoids. These rearrangements cannot be traced back to a simple model involving only a single or a few evolutionary events. The linear instability of the Y chromosomes gives some insight into the evolutionary isolation of large parts of the Y chromosomes and thus might reflect the isolated evolutionary history of the primate species over millions of years

Antioxidant Effects of Xanthohumol and Functional Impact on Hepatic Ischemia-Reperfusion Injury

Therapeutic effects of dietary flavonoids have been attributed mainly to their antioxidant capacity. Xanthohumol (1), a prominent flavonoid of the hop plant, Humulus lupulus, was investigated for its antioxidant potential and for its effect on NF-kB activation. To examine the biol. relevance of 1, a hepatic ischemia/reperfusion model was chosen as a widely accepted model of oxidative stress generation. The impact of 1 on endogenous antioxidant systems, on the NF-kB signal transduction pathway as well as on apoptotic parameters, and on hepatic tissue damage was evaluated. Compd. 1 markedly decreased the level of reactive oxygen species in vitro. Furthermore, levels of enzymic and nonenzymic antioxidants were restored after pretreatment in postischemic hepatic tissue, and lipid peroxidn. was attenuated. NF-kB activity was reduced in vitro as well as in hepatic tissue after ischemia/reperfusion upon pretreatment with 1. In addn., the phosphorylation of Akt was markedly inhibited. Surprisingly, 1 decreased the expression of the antiapoptotic protein Bcl-X and increased caspase-3 like-activity, a proapoptotic parameter. Moreover, hepatic tissue damage as well as TNF-alpha levels increased in xanthohumol-pretreated liver tissue after ischemia/reperfusion. In summary, xanthohumol did not protect against ischemia/reperfusion injury in rat liver, despite its antioxidant and NF-kB inhibitory properties