Ralf Kraus
University of Giessen
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Featured researches published by Ralf Kraus.
Journal of Pediatric Orthopaedics | 2008
Peter P. Schmittenbecher; Guido Fitze; Jan Gödeke; Ralf Kraus; Dorien Schneidmüller
Background: In displaced and unstable forearm shaft fractures, elastic stable intramedullary nailing represents the current treatment of choice. Delayed healing has been observed in single cases, but the incidence of healing disturbances remains unclear. Methods: Retrospective analysis of all patients with forearm shaft fractures and open epiphyseal plates, treated with elastic stable intramedullary nailing between 2000 and 2004 in 5 pediatric trauma units, was conducted. Evaluation of cases with insufficient consolidation 90 days after osteosynthesis was performed. Results: Ten (1.9%) of 532 cases showed delayed healing. Mean age (12.3 years), part of open fractures (30%), and part of open reductions (60%) were clearly higher than in a nonselected collective; the ulna was concerned in 70%. One refracture, 1 local soft tissue infection, and 1 small sequestration were found. In 5 children, nails were extracted with (2×) or without (3×) local surgical intervention. In the other 5 children, the nails were left in place. All fractures healed within 13 months posttrauma without relevant functional restrictions. Conclusions: Delayed healing is possible especially in open fractures or open reduced fractures of the ulna in older children, but healing takes place up to 13 months. Therefore, no change of treatment principles is necessary. Protection of ulna periost has to remain in the center of surgical focus. Level of Evidence: Retrospective comparative study, Level III.
European Journal of Trauma and Emergency Surgery | 2006
Christian Heiss; Ralf Kraus; Dominique Schluckebier; Ann-Christin Stiller; Sabine Wenisch; Reinhard Schnettler
Adhesives, especially bone adhesives, are resorbed and degraded to non-toxic products after fulfilling their function in contact with the living organism. The use of such bone adhesives has found growing interest in all fields of medicine in the last 50 years. The dream of trauma and orthopedic surgeons for alternatives to osteosynthesis and pins is reflected in the development of a variety of surrogates of biological or synthetic origin. Despite a longstanding history of research in this field up to now a clinically applicable alternative could not have been found on the field of bone gluing. The application consistently collapsed, because these adhesives were not tailored to the conditions met within the living organism. The following article is meant to provide an overview of the development, the state of the art and today’s knowledge of bone adhesives. In addition, the article wants to pinpoint the tremendous progress made on this subject, made possible by the joint effort of basic researchers and surgeons. The results show that in the future a successful reconstructive surgery will emerge from the application of synthetic biomaterials.
Journal of Pediatric Orthopaedics | 2008
Ralf Kraus; Urs Schiefer; Christoph Schäfer; Christof Meyer; Reinhard Schnettler
Background: Elastic stable intramedullary nailing (ESIN) is currently the therapy of choice in unstable, transverse and short oblique femoral and tibial-fibular shaft fractures in childhood and adolescence. As with every intramedullary technique, it requires a greater intraoperative reliance on radiological imaging. Literature concerning intraoperative radiation load in ESIN is rare, results having a wide range from less than 1 minute to more than 15 minutes. Methods: We performed a retrospective analysis of 53 femoral and 24 tibial shaft fractures. In addition, image intensifier times of several steps of the operative procedure in 10 femoral shaft fractures were evaluated prospectively. Results: The average radiation time in femoral fractures was 70.3 (range, 12-193) seconds, in tibial shaft fractures, 42.4 (range, 16-108) seconds. The prospective analysis of femur shaft fractures was able to show the most intense use of imaging during fracture passage (43.2%) and placement of the nail tips (26.6%). Image intensifier times in educational operations were not significantly higher than in operations performed by experienced surgeons. Conclusions: The actual intraoperative radiation load is influenced by bone mass and soft tissue coverage. Surgeons are able to reduce it only by decreasing the fluoroscopy time. According to our results, image intensifier time should not exceed 3 minutes in ESIN of femoral shaft fractures and 2 minutes in ESIN of lower-leg fractures. Low intraoperative radiation times are a mark of quality with respect to the interests of patients, surgeons, and operation theater staff.
BMC Musculoskeletal Disorders | 2011
Dorien Schneidmüller; Christoph Röder; Ralf Kraus; Ingo Marzi; Martin Kaiser; Daniel Dietrich; Lutz von Laer
BackgroundThe aim of this study was to develop a child-specific classification system for long bone fractures and to examine its reliability and validity on the basis of a prospective multicentre study.MethodsUsing the sequentially developed classification system, three samples of between 30 and 185 paediatric limb fractures from a pool of 2308 fractures documented in two multicenter studies were analysed in a blinded fashion by eight orthopaedic surgeons, on a total of 5 occasions. Intra- and interobserver reliability and accuracy were calculated.ResultsThe reliability improved with successive simplification of the classification. The final version resulted in an overall interobserver agreement of κ = 0.71 with no significant difference between experienced and less experienced raters.ConclusionsIn conclusion, the evaluation of the newly proposed classification system resulted in a reliable and routinely applicable system, for which training in its proper use may further improve the reliability. It can be recommended as a useful tool for clinical practice and offers the option for developing treatment recommendations and outcome predictions in the future.
Foot & Ankle International | 2004
Ralf Kraus; J.-P. Stahl; Christof Meyer; Theodorus Pavlidis; Volker Alt; U. Horas; Reinhard Schnettler
Background: Although calcification of the Achilles tendon has been described by several authors, a detailed evaluation of its frequency and effects on clinical outcome has not been reported. The purposes of this work were to determine the frequency of calcifications in the Achilles tendon after open repair and their effects on clinical outcomes and to identify possible risk factors for postoperative calcification. Methods: Thirty-six patients with open Achilles tendon repair were evaluated at an average followup of 19 months. Evaluation included a self-assessment questionnaire concerning treatment outcomes, clinical examination, and radiographic and ultrasonographic examinations. Results: No patient had calcifications in the Achilles tendon area before surgery. Postoperatively, intratendinous or peritendinous calcifications, ranging in size from 3 mm to 37 mm, were found in 10 (28%) of the 36 patients. The development of calcifications was associated with chronic swelling, decreased range of motion of the ankle joint, and increase pain, especially with calcifications larger than 10 mm. No association was found between the development of calcifications and the surgical technique, suture materials, time from injury to surgery, or postoperative management, and no risk factors could be identified. Conclusions: Calcifications of the Achilles tendon appear to be frequent after open tendon repair and to have a negative effect on clinical outcome.
Journal of Biomedical Materials Research Part B | 2009
Natali Bauer; Nina Brinke; Christian Heiss; Agnes B. Skorupa; Fabian Peters; Ralf Kraus; Reinhard Schnettler; Andreas Moritz
Bone gluing is an attractive surgical technique; however, its use in patients is hampered by a variety of side effects. Therefore, it was the aim of this ethically approved study to evaluate a novel biodegradable beta-Tri-Calciumphosphate (beta-TCP, Cerasorb)-enhanced bone adhesive regarding its toxicity and biocompatibility in a rabbit model. Fifty healthy New Zealand White rabbits were assigned in the study (n = 21) and sham-operated control group (n = 29). In the study group, a cylindrical part (4.6 x 10.0 mm) of the proximal tibia and distal femur was removed, reimplanted, and bone adhesive was applied. Blinded physical examination and sampling for hematology, clinical chemistry, and acute phase proteins (haptoglobin, C-reactive protein (CRP)) was performed before surgery and after 12, 24, 48, 72, 240, and 504 h. Significant findings of the physical examination included a slightly higher grading of warmth (p = 0.0019) and pain (p < 0.0001) of the wound 240 h after surgery in the study group. No significant differences between albumin, haptoglobin, CRP, and urea concentrations in both groups were evident, whereas the study group demonstrated significantly lower leukocyte count, total protein, and globulin concentrations (p < 0.0001). As expected, both groups showed a marked transient increase in muscle enzymes (Creatine Kinase and Aspartate Aminotransferase) following the surgery (p < 0.0001). Twelve to 24 h after surgery, a significant decrease in ionized calcium from 1.38 +/- 0.12 mmol/L to 1.06 +/- 0.13 mmol/L was noted in the study group (p < 0.0001). The results clearly indicated that the novel beta-TCP-enhanced bone adhesive showed good biocompatibility without significant evidence of acute or subacute local or systemic toxicity.
Unfallchirurg | 2011
Ralf Kraus; J.-P. Stahl; Christian Heiss; U. Horas; N. Dongowski; Reinhard Schnettler
BACKGROUND Only 1.5-2% of all fractures in children and adolescents are fractures of the thoracic and lumbar spine. Treatment is most often conservative. This study compares the own experience with the recent literature. MATERIAL AND METHODS Over a 48 month period all patients with fractures of the thoracic and lumbar spine, younger than 16 years were included prospectively. Of the patients 67 underwent follow-up investigations after 3-36 months. RESULTS The average age of the patients was 11.9 years. Sports (53%) and traffic (28%) accidents were most frequent. Fractures most often appeared in the mid-thoracic (47%) and thoracolumbar spine (41%). Operative treatment was performed in 9 cases (10.4%). Secondary loss of alignment was not observed neither after conservative nor operative treatment. Neurological deficits (n=2) did not completely improve. CONCLUSIONS Most fractures of the thoracic and lumbar spine heal fast and without any sequelae. Unstable fractures of type B and C (exclusively occurring as a result of traffic accidents) need operative stabilization as in adults.
Journal of Biomedical Materials Research Part B | 2008
Christian Heiss; Ralf Kraus; F. Peters; W. Henn; Matthias Schnabelrauch; A. Berg; T. Pautzsch; J. Weisser; Reinhard Schnettler
In this work, a novel bioresorbable bone adhesive based on radically polymerizable polylactide with methacrylate endgroups known from polymethylmethacrylate (PMMA) cements and varying amounts of bioresorbable/biodegradable lactide moieties was developed. The swelling and degradation properties as well as the hardening time, viscosity, and adhesion properties (tension and shear resistance) were subsequently measured in vitro and optimized. For a broad use in surgery the handling properties, the shelf life and the storage temperature are important issues. The finally developed material consists of three substances that have to be mixed to start the reaction: a highly viscous mixture of oligomers and two beta-tricalcium phosphate (beta-TCP, Cerasorb) powders with the radical starter and the promoter. The material has a processing time of 2 min and is completely cured after another minute. The tension and shear resistance of the material is 3.1-13.9 MPa that will decrease by storing the substance in a humid atmosphere. Degradation experiments showed a mass loss of 20-35% during the first 5 weeks. Tests with MC3T3-E1 cells showed an increase of the alkaline phosphatase activity over a period of 14 days. The mechanical and handling properties and the in vitro data are showing a promising biomaterial for bone regeneration.
Unfallchirurg | 2007
L. von Laer; Ralf Kraus
In the treatment of fractures of the long bones in children and adolescents, surgical and conservative methods are not mutually exclusive alternatives; rather, each can complement the other in the overall treatment strategy. Many operative procedures, such as fixation of juxtaarticular, metaphyseal fractures, need to be supplemented by conservative procedures, such as immobilization by means of casts. We refer to methods that are performed without anaesthesia and do not involve the implantation of osteosynthetic foreign material as conservative. These are: immobilization with no further treatment, plaster wedging, and functional treatment options. The indications for purely conservative treatment strategies are basically different for articular and nonarticular fractures. Whereas in the case of articular fractures only the nondisplaced fractures are treated by conservative methods, in the case of nonarticular (shaft) fractures those involving a degree of displacement, as long as it is not too pronounced to allow the integration of spontaneous corrections, can also be treated conservatively.
Clinical Anatomy | 2011
Ralf Kraus; June Reyers; Volker Alt; Reinhard Schnettler; Lars Daniel Berthold
To have knowledge of the physiological closure of a particular physeal plate is necessary to understand fractures close to the end of growth (transitional fractures). Most frequent fractures involve the distal radius in adolescents. However, there are no systematic investigations on the topic of growth plate closure concerning the distal radius plate, so far. Twenty‐two healthy female volunteers underwent MRI investigations of their left wrist. Absolute width, percentage and localization of the physeal part, closed at the time of investigation were recorded. Sequential MRI scans were performed. In this series T1‐weighted sequences were most useful to distinguish open and closed parts of the physis. Total area was 291–469 mm2 (average, 399 mm2). It did positively correlate with body height (P < 0.01), but not with weight (P = 0.241) or BMI (P = 0.394). Physeal closure took place at 15–18 years. There was no significant correlation between menarche and closure (P = 0.091). Bony bridging of the growth plate begins centroradial and ends with a small limbus dorsoradial. Sequential scans showed that there are only a few months from beginning to end of physeal closure. Physiological closure of the distal radius growth plate takes place in late adolescence, varying individually. There seems to be no influence of the menarche in female individuals. The process happens within a very short time of less than a year. This may be one rationale for the fact, that transitional fractures of the distal radius are rare. Clin. Anat. 24:1010–1015, 2011.