A standardized fracture reduction model for long bones--implication and evaluation in the femur.

Fractures of the femoral bone are frequent injuries with a wide range of affected individuals. New treatment strategies and technologies are being explored permanently. Their quality is biomechanically judged by the accuracy of the anatomical reduction. Malalignment of the fragments would have an eminent impact on the overall outcome and rehabilitation. To establish a method for investigations of the reduction results of femoral fractures, we developed a model, using a navigation system for taking measurement. The dynamic reference bases (DRBs) were mounted to the intact femoral bone and registered as the reference position. A special construction allowed removal and reattachment of the DRBs without provoking change in the DRB-bone system. The model was evaluated in its constancy. Translational deviations remained below 0.9 mm and rotational deviations below 0.3° after 40 repetitive reattachments. The model could prove to be valid and reliable. An application in long-bone trauma research is reasonable.

Robot-assisted fracture reduction using three-dimensional intraoperative fracture visualization: an experimental study on human cadaver femora.

Closed fracture reduction can be a challenging task. Robot-assisted reduction of the femur is a newly developed technique that could minimize potential complications and pitfalls associated with fracture reduction and fixation. We conducted an experimental study using 11 human cadaver femora with intact soft tissues. We compared robot-assisted fracture reduction using 3D visualization with manual reduction, using 2D fluoroscopy. The main outcome measure was the accuracy of reduction. The manual reductions were done by an experienced orthopedic trauma surgeon, whereas the robot-assisted reductions were done by surgeons of different experience. The robot-assisted group showed significantly less postreduction malalignment (p < 0.05) for internal/external rotation (2.9 degrees vs. 8.4 degrees ) and for varus/valgus alignment (1.1 degrees vs. 2.5 degrees ). However, the reduction time was significantly (p < 0.01) longer (6:14 min vs. 2:16 min). The higher precision associated with robot-assisted fracture reduction makes this technique attractive and further research and development worthwhile. In particular, less experienced surgeons may benefit from this new technique.

Hands-on robotic distal interlocking in intramedullary nail fixation of femoral shaft fractures.

INTRODUCTION: Intramedullary nailing has become the gold standard in the treatment of femoral shaft fractures. This procedure involves the placement of distal interlocking bolts using the freehand technique. Accurate placement of distal interlocks can be a challenging task, especially in inexperienced hands. Misplacement of distal interlocking bolts can lead to iatrogenic fracture, instability of the bone-implant construct, or even malalignment of the extremity. Repeated drilling attempts increase radiation exposure and can cause additional bony and soft tissue trauma. We hypothesize that robot-guided placement of distal interlocks is more accurate, precise, and efficient than the freehand technique. METHODS: A custom-designed drill guide was mounted onto the arm of an industrial robot. We developed a special device to secure a generic block (Synbone, Malans, Switzerland) into which an intramedullary nail could be inserted in a standardized way. A metric scale allowed later measurements of the drillings. Digital images were taken from each side of the block for analysis of the drilling trajectories. The fluoroscope was adjusted to obtain perfect circles of the distal interlocking holes. The number of images necessary to achieve this was recorded. The axis was recognized automatically by using the differences in contrast between the matrix of the generic bone and the implant (intramedullary nail). The drill trajectories were then computed. The robot with the mounted drill-guide automatically moved onto the calculated trajectory. The surgeon then executed the drilling. We performed 40 robot assisted drillings in generic blocks. Freehand drilling served as our control group. RESULTS: Analysis of the digital images revealed a mean deviation of 0.94 mm and 2.7° off the ideal trajectory using robotic assistance. In 100% of the cases (n = 40), the distal locking hole was hit. A mean of 8.8 images was acquired. After manual drilling, 92.5% of the distal interlocks were hit. A mean deviation of 3.66 mm and 10.36° was measured. A mean of 23.4 fluoroscopic images were needed. The differences between the two methods were statistically significant. CONCLUSION: Robot-guided drilling increases the accuracy and precision of distal interlocking while reducing irradiation. Considering economical and logistical aspects, this application should be integrated with robot-guided fracture reduction.

An internet based learning tool in orthopaedic surgery: preliminary experiences and results.

Today universities can offer a variety of educational resources to their students through the internet. These may include lecture notes, PowerPoint presentations, or even an entire recording of a lecture in video format. At the Hannover Medical School (Hannover, Germany), the Trauma Surgery Department in collaboration with the Institute of Medical Informatics has developed an alternative method of "E-learning". We created a web-based multimedia resource center for Trauma Surgery using the Content-Management-System (CMS) Schoolbook application, which was initially developed by the Institute of Medical Informatics. The so called "Trauma Surgery Schoolbook" was first adopted in October of 2005 and has since been used and evaluated by medical students at our institution. The evaluation results for the academic year 2005/06 are reported in this paper. The majority of students enrolled in the Trauma Surgery rotation utilized the Schoolbook, which they regarded as a helpful and effective study tool. Our students embraced the possibility of being able to prepare for lectures and use the Schoolbook for independent home studying purposes. Over time, there was a steady increase in the utilization of the Schoolbook by the students from 67% in the first trimester to 93% in the third trimester. The majority of the surveyed students (79.6%) found the Schoolbook to be constructive and helpful. 8.1% did not have any opinion, and only 12.3% found it to not be helpful. The instructors also found this web-based training program to be both constructive and practical, and were able to utilize its multimedia components to complement their lectures. Overall, our experience with this computer-aided learning program demonstrated that web-based technologies can improve the quality of medical education, benefiting both the students and the instructors.