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Biomedical subjects

C Krettek

Publications and source records attributed to C Krettek.

At least 109 records · Page 6Linked to original sources

[Grisel syndrome--a trauma surgery rarity].

Atlanto-axial fixed subluxation (Grisel's syndrome) is an uncommon complication of upper neck inflammatory processes and head and neck surgery. We present the case of a 6 year old patient who developed a Grisel's syndrome after an upper respiratory infection. X-rays and CT scans demonstrated a fixed C1 and C2 subluxation which was treated with reposition and application of a Halofixateur. We give a review of the pathogenesis, diagnosis and treatment of this rare syndrome.

Atlanto-Axial Joint↗

[Tissue engineering of tendons and ligaments. A new challenge].

Injuries to ligaments and tendons heal by formation of inferior repair tissue. This may result in severe joint dysfunction. Because of an increased occurrence of sports-related injuries, musculoskeletal disorders may become one of the major burden of health care. Tissue engineering offers the potential to improve the quality of ligament and tendon tissues during the healing process and may provide a more effective approach to the treatment of injuries to ligaments and tendons than traditional methods. Application of growth factors, gene transfer techniques, cell therapy and cell-matrix composites have shown to affect the process of ligament and tendon healing. The benefits of using mesenchymal stem cells on a three dimensional biological matrix have been shown recently. Tissue engineering will also include mechanical manipulation of tissue environments to accelerate cell differentiation and to improve matrix formation. Fibroblast-seeded polymer scaffolds could be useful in ligament and tendon replacement in which autogenous fibroblasts would be obtained through biopsy, cultured and seeded onto a scaffold.

Animals↗

[Treatment approaches in gunshot injuries of the extremities].

In the view of efficiency and cost effectiveness the increasing incidence of gunshot wounds in Europe demands a modification of treatment protocols. The general basis are debridement of soft tissue injuries, antibiotics and fracture stabilization. The pathology of gunshot wounds and established treatment algorhithms, however have to be adjusted to the ongoing development of gun technology and the thereby caused specific lesions. The treatment of injuries caused by high velocity projectiles necessitates a proactive surgical strategy. Small caliber gunshot wounds can be treated more conservatively. The following review presents an overview on the ballistic and surgical basis for the treatment of gunshot wounds of the musculoskeletal system.

Arm Injuries↗

[Pediatric prehospital trauma care. A retrospective comparison of air and ground transportation].

OBJECTIVE: In contrast to prehospital care of adult trauma victims, prehospital care providers have only limited clinical experience of pediatric trauma cases as these are relatively infrequent. Literature reports on prehospital pediatric trauma care given by paramedics are frequently found in the literature, but there are few publications analyzing the quality of prehospital trauma care provided by emergency physicians in the care of injured children. It was the goal of this study to analyze the prehospital care of the pediatric trauma victims transported to a trauma center by physician-staffed ambulances and helicopters. METHODS: The study took the form of a retrospective 5-year review of pediatric trauma patients admitted to a trauma center. The inclusion criteria were age younger than 13 years and a NACA score higher than 3. In all, 104 patients were included, and these were divided into two groups, those transported to hospital by helicopter (RTH, n=87) and those taken to hospital by road ambulance (NEF, n=17). RESULTS: With a mean NACA score of 4.6 and a mean ISS of 15, no significant differences were found between the two groups in either severity of injury or length of hospital stay. The mortality of the total patient population was 15.4%, with no evidence of preventable deaths in patients who were admitted to the trauma center with vital signs. Analysis of prehospital therapy showed no differences in the volume of intravenous fluids administered (RTH 636 ml vs NEF 476 ml) or in the proportion of children with a GCS<9 in whom endotracheal intubation was implemented (RTH 39/44 vs NEF 7/7). Placement of more than one i.v. line and endotracheal intubation were associated with longer times at the scene of the accident before patients were taken to hospital (>one i.v. corresponded to 9 min longer, and endotracheal intubation, to 10 min longer). CONCLUSIONS: Prehospital pediatric trauma care delivered by physician-staffed ambulances or rescue helicopters is associated with a high rate of i.v. line placement (92%) and high intubation rates (90%) in patients with an altered level of consciousness (GCS<9). The prehospital care provided by helicopter or ground ambulance personnel was not different and was not associated with longer stays in the intensive care unit or longer overall stays in hospital. Scene times became longer with increasing number of i.v. line placements and with endotracheal intubation, but was not prolonged by a greater severity of injury as determined by the ISS. Preventable deaths were not observed in the patient population. In summary, owing to the the local infrastructure, pediatric trauma patients are more frequently transported to the trauma center by air (87 by air vs. 17 by road per 5-year time period). However, despite being less frequently involved in the case of pediatric trauma, the quality of care provided by road ambulance staff is similar to that in air ambulances.

Air Ambulances↗

Plantar impact causing midfoot fractures result in higher forces in Chopart's joint than in the ankle joint.

PURPOSE: Force effect (impact, extent of foot compartment deformation) and result (fracture pattern) for midfoot fractures in car occupants is known. An analysis of the processes in the foot was intended to improve car safety. MATERIALS AND METHODS: Eleven fresh, unfrozen, unpreserved intact human cadavers (age: 36.8 (16-61) years, gender: male, race: Caucasian) were studied 24-72 h after death. In 3 cadavers (5 feet) the experimental design was established: entire cadaver fixed on a special tray in supine position, pendulum with bar impactor hitting the foot plantar to Lisfranc's joint. A custom-made pressure sensor was inserted in the ankle (A), talonavicular (TN) and calcaneocuboid (CC) joints (resolution: 1 cm2, sampling rate: 500/s). RESULTS: Sixteen feet were measured: midfoot fractures were induced in 11 feet. The maximum pressure amounted to 1.22-2.55 MPa (2.04+/-0.412) at 0.005 0.195 s (0.067+/-0.059) after impact. The maximum pressure occurred in 8 (50%) cases in the ankle, in 7 (44%) of the TN and 1 (6%) of the CC joints. A comparison of the first 200 pressure samples after impact of all sensor fields resulted in higher forces in Chopart's joint than in the ankle (t-test: p < 0.001). These force differences were higher in cases with midfoot fractures (mixed model analysis of variance: p = 0.003). CONCLUSION: Due to considerable forces in Chopart's joint we recommend a modification of the actual crash test dummy lower extremity model with an additional load cell that detects forces in the longitudinal direction of the foot axis.

Adolescent↗

Computer-assisted fracture reduction of pelvic ring fractures: an in vitro study.

A newly developed software module for computer-assisted surgery based on a commercially available navigation system allows simultaneous, independent registration of two fragments and real-time navigation of both fragments while reduction occurs. To evaluate the accuracy three fracture models were used: geometric foam blocks, a pelvic ring injury with disruption of the symphysis and the sacroiliac joint, and a pelvic ring fracture with symphysis disruption and a transforaminal sacral fracture. One examiner did visual and navigated reduction and in all experiments the end point was defined as anatomic reduction. Residual displacement was measured with a magnetic motion tracking device. The results revealed a significantly increased residual displacement with navigated reduction compared with visual control. The differences were low, averaging 1 mm for residual translation and 0.7 degrees for the residual rotation, respectively. Residual displacement was small in both set-ups and may not be clinically relevant. Additional development of the software prototype with integration of surface registration may lead to improved handling and facilitated multifragment tracking. Use in the clinical setting should be possible within a short time.

Biomechanical Phenomena↗

Adenoviral gene transfer in a rat fracture model.

For the enhancement of fracture healing, either purified proteins or vectors for expression of growth factors in situ may be used. Adenoviral vectors directly convert cells to express a transgene. However, the cell types which are preferentially infected and the time of expression during fracture healing are currently not known. The adenoviral type 5 vectors used in this study are replication incompetent viruses, one encoding beta-galactosidase (beta-GAL) and one green fluorescent protein. Femora of 35 Sprague-Dawley rats were fractured. Three days after stabilization with Kirschner wire, 10(12) pfu viral suspension were injected into the fracture zone. As a control, five animals received injections of adenovirus type 2. Animals were sacrificed after 3 days, 1, 2 and 4 weeks. Fractures healed radiographically within 2-3 weeks. All specimens were examined for beta-GAL and green fluorescent protein (GFP) expression. Fibroblast and osteoblasts within callus tissue displayed a high transgene expression (week 1). A decrease of expression was observed during the observation period. In this experimental study, we have demonstrated that all cells of the primary callus can be transfected using adenoviral vectors, which provide a tool to further investigate adenoviral transfer of growth factors such as bone morphogenetic protein-2 (BMP-2).

Adenoviridae↗

Fractures of the glenoid treated by operation. A 5- to 23-year follow-up of 22 cases.

We describe the results after open reduction and internal fixation of 22 consecutive displaced fractures of the glenoid with a mean follow-up of ten years. A posterior approach was used in 16 patients and an anterior in six, the approach being chosen according to the Ideberg classification of the fractures. The fixation failed in two patients, one of whom required a further operation. There were two cases of deep infection. At follow-up the median Constant score was 94% (mean 79%, range 17 to 100). The score was less than 50% in four patients, including the two who became infected. A further two had an associated complete palsy of the brachial plexus.

Adolescent↗

Review: systemic effects of femoral nailing: from Küntscher to the immune reactivity era.

Intramedullary nailing is the preferred treatment for stabilizing femoral diaphyseal fractures. Despite the superior biomechanical advantages over other implants, its use especially in some selected groups of patients, has been questioned because of possible harmful systemic effects of intramedullary reaming. The lung seems to be the primary target for fat embolization and for mediated effects by inflammatory reactions. The latter are initiated in the immediate aftermath after injury, and femoral nailing can amplify these responses. The role of reaming in the context of early femoral fracture fixation in the patient experiencing trauma is debatable. This review article focuses on the evidence that has emerged during the past century regarding the systemic effects of femoral nailing.

Animals↗

Computer-assisted fracture reduction: novel method for analysis of accuracy.

Anatomic reduction of displaced fractures is limited by the chosen surgical approach and intraoperative visualization. Preoperative Computed Tomography (CT) enhances the analysis of the fracture pattern and provides accurate spatial relationships. Computer Assisted Surgery (CAS) was introduced to increase the accuracy of specific surgical procedures. CAS systems can be used for implant placement or osteotomies in intact bone or reduced situations prior to obtaining the CT data, as differentiation into different datasets related to specific fragments is not yet possible. We present a model that allows "virtual" controlled reduction, providing computer assistance during the fracture reduction. Prior to clinical application, the accuracy of the process of virtual reduction must be proven in an experimental setting. An in vitro fracture model with two body fragments and a motion tracking system for three-dimensional (3D) control (accuracy 0.1 mm and 0.1 degrees ) was used. Two methods were employed: direct visualization and reduction by the examiner, and "virtual" reduction, performed solely with the use of a computer image, in which the examiner lacks any direct visualization of the fragments. The results of this very simplified "fracture" model indicate that the overall difference between direct and virtual controlled reduction was very small. A significant difference of 0.3 mm (0-1.8 mm) was seen for the residual displacement represented by the Euclidean distance (p < 0.01), whereas the difference in the residual angulation was not significant (p > 0.05). The methods tested revealed that virtual controlled reduction is nearly as accurate as direct visualization. Reduction control utilizing a motion tracker system reveals accurate 3D information in this simplified reduction setup, and is now used as a standard setup for analyzing realistic fracture models.

Fracture Fixation↗

Peer relations of adolescents from nuclear and separated families.

Problems of psychosocial adjustment as a consequence of parental separation have mostly been studied concerning aspects of family relations and individual growth. The present study examined peer relations of young people between the ages of 10 and 20 years old who lived in nuclear families, step-families, and single-parent families. Based on the second questionnaire assessment of a longitudinal study conducted in East and West Germany, reports from a total of 637 boys and girls on deviant and constructive peers in their social network as well as on the quality of their relations with best friends were analysed. Findings suggest that peer relations were affected by parental separation only to a minor extent as compared to, e.g. gender- or age-specific effects. A central aspect of friendship quality, however, namely admiration by friends, clearly suffered from conflict between mothers and fathers.

Adolescent↗

[Long-term outcome after multiple organ failure following severe trauma].

OBJECTIVE: The aim of this follow-up study was to find out if severely injured patients with multiple organ failure (MOF) show any organotopic sequelae in the late course. Additionally the occupational rehabilitation result as well as the reasons for a poor occupational result were investigated. METHODS: A total of 50 MOF patients with an injury severity of 45.3 +/- 2.1 PTS points were followed up 4.9 +/- 0.3 years after trauma. In order to show any organotopic sequelae, patients were examined and laboratory tests for the function of the lungs (function test, Horovitz-quotient), liver (bilirubin, GOT, bleeding time), and kidnies (creatinine, urea) were performed. The functional (locomotion and neurological system) and occupational rehabilitation results as well as the reasons for a poor occupational result were analysed. RESULTS: The clinical examination as well the functional and laboratory tests showed mainly normal results but in in 25% of the patients a significantly decreased range of motion of the elbow, hip, knee and ankle joint was found. The "return to work rate" was 64%. Reasons for a poor occupational result were the severity of head injury, a decreased range of motion of the hip joint and general physical fitness. CONCLUSIONS: Severely injured patients who survive MOF during their intensive care treatment, show no sequelae of organ failure. The occupational rehabilitation results were excellent with a "return to work rate" of 64% which was dependent on the severity of head injury, a decreased range of motion of the hip joint and general physical fitness.

Adolescent↗