[Injuries and injury risk in skiing and snowboarding]. / Verletzungen und Verletzungsrisiko beim Ski- und Snowboardsport.

INTRODUCTION: An extensive gathering of data should contribute to evaluate the risk and to reduce prejudices. MATERIAL AND METHOD: Within 6 weeks 57 different criteria according to accident, person and circumstances from 3,512 skiers and snowboarders were gathered and collected in a database. For analysis additional data about frequency of transportation and weather and piste conditions were available. RESULTS: Injury risk for piste sports is 0.7%. The risk is especially influenced by bad weather conditions. Young people represent a risk group. The carving technique has led to a reduction of injury risk, but caused a shift of the injury pattern. Protectors reduce the risk up to 50%. DISCUSSION: Skiing and snowboarding are among the safest sports because of improved material and pistes. The new injury pattern with the carving technique is due to higher speeds in curves resulting in higher centrifugal forces; 18% of skiing accidents are collisions and 14% of all skiers do not know the FIS rules of conduct. CONCLUSION: There was no increase in injury risk at the pistes in recent years. The use of protectors has a positive effect and should be supported in the future too.

Comparison of ender nails, dynamic hip screws, and Gamma nails in the treatment of peritrochanteric femoral fractures.

Three hundred seventy-six patients with peritrochanteric fractures treated over a 10-year period were reviewed. In 85 patients treated with Ender nailing, the most frequent complications were leg shortening (34), external rotation failure (21), and postoperative distal gliding of the nails (7). In 183 patients treated with dynamic hip screws or a 95 degree condylar or a 130 degree blade plate, 3 presented with infection, 5 with instability, and 4 with femoral head necrosis. In 105 patients treated with Gamma nailing, the most serious complications were infections (3), inward rotation failure (2), postoperative bleeding at the insertion site (2), and shaft fracture (1). Because of its inherent instability, Ender nailing is no longer used. The implantation technique for the dynamic hip screw is safer and simpler than the various models of the ASIF blade plate. However, the dynamic hip screw has been superseded by the Gamma nail because of its absolute stability. In the beginning, Gamma nailing was technically more demanding with a higher number of intraoperative complications. In this study, the number of malalignments did not differ significantly between the dynamic hip screw (14) and the Gamma nail (11), but was high with Ender nailing (56).

[Miniature thin layer biosensors which are sensitive to glutamate and glutamine]. / Miniatiurnye tonkoplenochnye biosensory, chuvstvitel'nye k glutaminovoi kislote i glutaminu.

Integrated thin film biosensors for simultaneous measurement of L-glutamine and L-glutamate in a micro-flow cell were developed. Due to a novel glutaminase with an activity optimum in the neutral pH range a direct monitoring of glutamine in mammalian cell culture medium could be performed. The glutamine bienzyme sensor was prepared by coimmobilization of glutaminase with glutamate oxidase within a photo patterned poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel membrane. The sensor response is linear in the concentration range of 55 mmol to 10 mmol glutamine/l. Additionally a glutamate biosensor is integrated on the sensor chip for difference measurement of possible glutamate interferences. The sensor chip can be used for at least 300 measurements without any alteration in the performance of its sensors. A new sensor chip with an integrated flow cell provides the possibility of simultaneous measurement of four different parameters at a cell volumina of 1 ml. Completing the microsystem a battery operated surface mounted device (SMD) potentiostat was developed to get a "lab on chip".

Thin-film microbiosensors for glucose-lactate monitoring.

A miniaturized device for simultaneous measurement of glucose and lactate levels was produced by means of photopatterning of enzyme-containing photosensitive membrane precursors. This device shows no cross-talk and a lifetime for both the glucose and the lactate sensors of more than 2 weeks when continuously operated in undiluted bovine serum. Linear response ranges of up to 40 mM for glucose and 25 mM for L-lactate, in combination with 95% response times of < 30 s, were realized. The devices are mass produced by means of thin-film technology on flexible carriers to give catheter-type multisensing devices for in vivo applications. Ex vivo experiments, performed with human volunteers, where the device was continuously operated in an extracorporeal, undiluted, heparinized blood stream for 6 h, gave a correlation of r > 0.98 with respect to laboratory techniques. Subcutaneous measurements of glucose levels in pigs were close to the corresponding blood levels obtained without in vivo calibration.

Miniaturized thin film glutamate and glutamine biosensors.

Integrated thin film biosensors were developed for the simultaneous measurement of L-glutamine and L-glutamate in a mu-flow cell. Due to a novel glutaminase with an activity optimum in the neutral pH range, direct monitoring of glutamine in a mammalian cell culture medium could be performed. The glutamine bienzyme sensor was prepared by co-immobilization of glutaminase with glutamate oxidase within a photopatterned poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel membrane. The sensor response was linear in the concentration range of 50 mumol to 10 mmol glutamine/l. Additionally, a glutamate biosensor was integrated on the sensor chip for difference measurement of possible glutamate interferences. The sensor-chip could be used for at least 300 measurements without any alteration in the performance of its sensors. A new sensor-chip with an integrated flow cell provided the possibility of simultaneous measurement of four different parameters at a cell volume of 1 microliter. In order to complete the microsystem, and in order to obtain a "lab on chip", a battery operated surface mounted device (SMD) potentiostat was developed.

Miniaturized integrated biosensors.

Miniaturized integrated thin-film biosensors were developed for use in clinical analyzers and for in vivo applications. A glucose and a lactate sensor were integrated with a pH-sensor on a flexible substrate. Both enzyme sensors are based on the electrochemical measurement of H2O2 produced by the enzymes glucoseoxidase and lactateoxidase respectively. The solid state pH-sensor uses a neutral carrier membrane. The intended application of this device is the monitoring of metabolic parameters in the intensive care unit and the operation theater and the use as a sensor module in clinical analyzers. The glucose-, lactate- and pH-sensor was tested in buffer solutions and undiluted serum showing excellent performance.