Biomedical subjects

H-J Egbers

Publications and source records attributed to H-J Egbers.

4 recordsLinked to original sources

PubMed2006

[Preventing malrotation during intramedullary nailing of femoral fractures].

BACKGROUND: The problem of preventing malrotation after closed intramedullary nailing of femoral shaft fractures has not been solved yet. As clinical tests and radiologic criteria for intraoperative use provide little accuracy, the theoretical basis for a C-arm-based measurement of the femoral antetorsion was analysed. METHODS: The directions of femoral neck axis and condylar axis can be identified by the radiologic views "knee joint, lateral view" and "hip joint, axial view". The rotation of the C-arm in relation to a horizontal axis to achieve these views can be measured in degrees. Theoretically, the difference between these rotation angles could be used to calculate the antetorsion. Intact plastic femora (Sawbone) and a femoral shaft fracture model were used to research optical and geometrical phenomena that influence a direct measuring technique. RESULTS: Several geometrical phenomena were observed, making direct measurement with arithmetic corrective factors not recommendable. For practical reasons, a data table was created, correlating the difference between the two C-arm angles with true antetorsion. In an interobserver trial with 18 trauma surgeons, the method proved to achieve high accuracy with a maximum interobserver variation of 5 degrees. CONCLUSIONS: The method is easily reproducible, reliable and can be recommended to every surgeon. Due to the wide range of physiological antetorsion angles in different individuals, fair results can be expected controlling the rotation with standard value tables, and excellent results can be expected using bilateral measurement.

Femoral Fractures↗

PubMed2005

[Technique for percutaneous iliosacral screw insertion with conventional C-arm radiography].

BACKGROUND: During percutaneous iliosacral screw fixation, fluoroscopy with a conventional C-arm X-ray unit is still the standard procedure for intraoperative orientation. Lateral sacral images in combination with the inlet and outlet view are always necessary. Nevertheless, the complex pelvic anatomy makes it difficult to prevent malpositioning of screws. OPERATIVE TECHNIQUE: Defining the correct entry into the bone is the decisive step for ideal screw placement. The better this is defined, the larger safety margins will be concerning cortical perforation by the screws. In the lateral view, an entry ventral to the sacral canal has to be avoided as well as an entry into the cranial half of the first sacral vertebra. To improve the surgeon's three-dimensional orientation with the help of his personal experience and two-dimensional images, it is recommended to place the tip of the screws in the center of the sacrum (in AP view) whenever possible. Routinely performed postoperative CT imaging of 24 screws, consecutively implanted according to the standards described, revealed no case of malpositioning. CONCLUSION: Standard X-ray views in combination with standardized aiming of screw entry position and final screw thread position enable the surgeon to find the "safe zone" for iliosacral screw insertion and to prevent iliosacral screw malpositioning with high accuracy.

Bone Screws↗

PubMed2005

[Comparison of spine injuries by means of CT and MRI according to the classification of Magerl].

PURPOSE: A feasibility study of the classification of spine injuries by CT and MRI data according to the classification of Magerl for spine injuries. MATERIAL AND METHODS: In 39 patients, 46 injured vertebrae were evaluated by means of CT and MRI. A single-slice helical CT (Somatom Plus S, Siemens, Erlangen, Germany) was used with a collimation and feed of 2 mm and 3 mm, respectively. Sagittal reformations were reconstructed from these data sets. MR imaging was performed with 1.5T and 1.0T machines (Magnetom Vision and Magnetom Impact, Siemens). Transverse and sagittal T1-w SE- images as well as sagittal T2-w TSE- and STIR-images were generated. Each fractured vertebra was independently categorized two times according to the classification of Magerl on the basis of CT- and MRI-images. The CT- and MRI-classifications were subsequently compared. RESULTS: Most fractures were classified as impaction fractures (A1) or burst fractures (A3). Only 5/46 injuries of vertebrae were not given the same classification by means of CT and MRI (r = 0.9). MRI showed more bony lesions than CT (n. s., p > 0.05) and was able to evaluate ruptures of the longitudinal ligaments in 5 patients. CONCLUSION: Classification of spine injuries according to the Magerl-classification showed a significant agreement between CT and MRI and therefore a comparable evaluation of stability. MRI was superior in delineating ligamental lesions.

Adolescent↗

PubMed2004

[Injury pattern caused by aggressive inline skating].

In order to evaluate the special injury pattern of aggressive inline skating, a field study was conducted in a local, non-commercial skate park equipped with all the typical features like ramps, halfpipes, gully areas. 66 unselected aggressive inline skaters were randomly enrolled and interviewed concerning their skating habits and their skating injury history. Average age was 15 (10 to 41) years, skating was performed since 2.1 (0.1 to 6) years, as aggressive skating since 1.3 (0.1 to 4) years. Medical treatment in a doctor's practice or in a hospital had been necessary in 66 cases, averaging 1.4 times per skater and year, averaging one injury per 586 hours of aggressive skating. The injury pattern reflected the regions typically injured in fitness skating, too, with a higher percentage of injuries concerning knee, tibia and ankle region. The use of protective devices varied from 41 % (wrist guards) to 94 % (knee pads), with an average of 69 %. Only 32 % of skaters wore all protective devices. As the personal thrill is an important motivation for aggressive skating, safer skating campaigns are quite unlikely to decrease the risk of injury in aggressive skaters.

Adolescent↗