[An optimised assessment of "severely injured patients" for the documentation of road traffic accident black spots]. / Eine optimierte Bewertung "Schwerverletzter" zur Dokumentation von Unfallschwerpunkten im Straßenverkehr.

INTRODUCTION: The success of traffic safety improvement strategies is based on documentation. Analysis and remedy of accident black spots in addition to improvements in automobile production involve the work of traffic engineers, politicians, traffic regulations, police, and medical care. To create priorities, the traffic statistics differentiate accidents in a 3-class system in relation to severe accidents: slightly injured, severely injured and fatally injured (death). This study assesses the validity of the existing classification of "severely injured" compared with the actual injury severity. MATERIAL AND METHOD: We analysed accidents resulting in 182 "severely injured" people in one year in a city model. A synchronisation of anonymous police documentation with the medical notes of admitted casualties which were validated by established trauma scores and medical classification was undertaken. A correlation analysis of length of stay should give indications of the actual injury severity. RESULTS: The study group showed a ubiquitous range of age, sex and injuries despite a relatively low case number. The range of MAIS, ISS and NACA index scores shows the inhomogeneity of the people classified as "severely injured". 70 % of the study group revealed ISS < 16 which means that they are not polytraumatised patients. The correlation analysis according to Spearman certifies the validity of these scores (r MAIS/NACA = 0.645 and r ISS/NACA = 0.592). The further differentiation on the basis of MAIS, ISS and NACA showed that 51 % of the study group should be classified as slightly injured and 83 % of these were discharged in less than 5 days. CONCLUSION: This study shows that the traffic safety classification of "severely injured" people is not sufficient and most severely injured people are not even approximately recorded. We propose that a new continuous link system between police and medical data will be inevitable for future improvements in traffic safety. The use of established trauma scores and a differentiated look at lengths of stay could be an option.

[Unstable pertrochanteric femur fractures. Failure rate, lag screw sliding and outcome with extra- and intramedullary devices (PCCP, DHS and PFN)]. / Die instabile pertrochantäre Femurfraktur. Komplikationen, Fraktursinterung und Funktion nach extra- und intramedullärer Versorgung (PCCP, DHS und PFN).

AIM OF THE STUDY: The dynamic hip screw (DHS) often shows a high incidence of therapeutic failure and an impared outcome in the treatment of the unstable pertrochanteric femur fracture (31A2). Therefore often an intramedullary device is recommended. In a retrospective clinical study we examined whether the percutaneous compression plate (PCCP, Gotfried) provides advantages following unstable fractures in comparison to DHS and PFN. METHODS: From January 2002 to April 2007 135 patients with unstable pertrochanteric femur fractures underwent internal fixation with the PCCP (n = 46, age 78.3, ASA 2.8), DHS (n = 36, age 75.9, ASA 3.0) or PFN (n = 53, age 77.2, ASA 2.8). Radiological and clinical re-examination of the patients (33 PCCP, 24 DHS, 34 PFN) was performed 17 months later. RESULTS AND DISCUSSION: The PCCP was implanted in less time than the DHS and PFN (59 vs. 80 vs. 79 min, p = 0.004). Radiographic screening time was low (PCCP 143 vs. DHS 146 vs. PFN 280 s, p = 0.001). Re-operations for wound infections and haematomas occurred in 2 % after PCCP, 14 % after DHS and 4 % after PFN (p = 0.058). There was a low re-operation rate for fracture fixation complications in PCCP (9 %), in contrast to DHS (25 %) and PFN (13 %, p = 0.109). Cut-out was seen more in DHS (19 %, PCCP 2 %, PFN 4 %, p = 0.005). Lag screw sliding was high with DHS (PCCP 4 mm vs. DHS 9 mm vs. PFN 6 mm, p = 0.032). There was no correlation between lag screw sliding and outcome. PCCP, DHS and PFN had the same functional results in Merle d'Aubigné and Harris hip scores. CONCLUSIONS: Using the minimally invasive PCCP technique in unstable pertrochanteric femur fractures provides a promising therapy option especially with regard to surgical time, radiographic screening time and failure rate. Lag screw sliding was low. There was no advantage of the intramedullary device PFN.

Biomimetic modification of the TiO(2)/glass composite Ecopore with heparinized collagen and the osteoinductive factor BMP-2.

The porous TiO(2)/glass composite Ecopore has potential applications in hard tissue replacement. We describe the modification of Ecopore with the growth factor bone morphogenetic protein-2 (BMP-2) to add osteoinductive properties. Ecopore covalently coated with BMP-2 caused a weak induction of alkaline phosphatase in murine embryonal fibroblasts. In a rabbit bone defect model, BMP-2-coated Ecopore had moderately higher bone apposition rates and ingrown bone quantities at 6 weeks after implantation. To overcome loss of function due to chemical surface coupling, we filled the pore system of Ecopore with heparinized collagen sponge and loaded this secondary matrix with BMP-2. Heparinization of collagen filling increased the BMP-2 loading capacity of the matrix approximately 1.28-fold. Within 96 h, 17.0+/-0.1 and 10.1+/-0.2% of the used BMP-2 was released from non-modified and heparinized Ecopore/collagen, respectively, indicating that the heparin modification retarded BMP-2 release. Revealed by energy-dispersive X-ray spectroscopy analysis of implant cross-sectional areas, BMP-2-loaded Ecopore/collagen had significantly higher bony ingrowth quantities in rabbits, with the heparinized modification yielding the highest value (16.09+/-3.51%, p<0.005) compared with the non-heparinized matrix (10.72+/-4.07%, p<0.05) and the BMP-2-free controls (5.60+/-1.47%). This suggested a beneficial effect of the biomimetic modification of Ecopore with heparinized collagen for bone healing and integration.

[Surgical outcome in pertrochanteric femur fracture: the impact of osteoporosis. Comparison between DHS and percutaneous compression plate]. / Operationsergebnisse nach pertrochantärer Femurfraktur: Welchen Einfluss hat die Osteoporose? Vergleich zwischen DHS und perkutaner Kompressionsplatte.

AIM: The dynamic hip screw (DHS) often shows an impared outcome and a high incidence of therapeutic failure in patients with osteoporotic pertrochanteric femur fractures. This is caused predominantly by a fracture collapse and appears often in unstable fractures (31A2, 31A3). In a prospectively documented clinical study, we examined whether or not the percutaneous compression plate (PCCP, Gotfried) offers advantages following osteoporotic fractures. METHOD: From August 2003 to December 2005, 103 patients underwent internal fixation with the DHS (n = 40, age 76.1, ASA 2.9) or with the PCCP (n = 63, age 76.9, ASA 2.8). Proximal femurs were classified with the Singh grading system, which uses six grades of trabecular patterns to describe the degree of osteoporosis. Reexamination of the patients (27 DHS, 43 PCCP) was performed on average 18 months later. RESULTS: The PCCP was implanted into very osteoporotic femurs (Singh 2) in less time than the DHS (47 vs. 79 min). These patients treated with PCCP showed no difference in blood loss, but tended to have better outcomes (Merle d'Aubigné, Harris hip score) than those treated with DHS. Life quality, subjectively measured with the visual analogue score, was significantly better in the PCCP group with high-grade osteoporosis (Singh 2). The outcome after implantation of the PCCP was not correlated to the Singh index in stable or in unstable fractures. Mechanical complications occurred especially in unstable fractures (re-operation rate: DHS 4/18 [22 %], PCCP 3/29 [10 %], p = 0.266), without correlation to the Singh index. Excluding the avoidable complication of loosening of the screw-barrel portion, the re-operation rate for the PCCP was 3 % (cut-out: 1/29, p = 0.042) in unstable fractures. CONCLUSION: Use of the minimally invasive PCCP technique in osteoporotic pertrochanteric femur fractures provides an alternative to the dynamic hip screw, especially with regard to surgical time and outcome. Advantages occurred also in the re-operation rate following fracture fixation complications. The cut-out rate was significantly lower than in the DHS group in unstable fractures.

[Biomechanical tests of a new scaffold for the cultivation of chondrocytes]. / Biomechanische Testung einer neuen Trägermatrix für die Kultivierung von Chondrozyten.

AIM: Scaffolds for the cultivation of chondrocytes are of increasing importance. So far, only little is known about their biomechanical properties. The present preliminary study addresses the biomechanical characteristics of a new collagen type I scaffold for the cultivation of chondrocytes. MATERIAL AND METHODS: Human chondrocytes were amplified in a monolayer and then cultivated in a 3D-scaffold over a period of up to 6 weeks. The biomechanical tests addressed the properties under uniaxial compression including stiffness and viscoelastic characteristics (creep and retardation). The obtained values were normalized against the thickness of the specimens and expressed as ratios. In addition, we present histological and quantitative PCR results (for collagen type II and aggrecan). RESULTS: The maximum force (or penetration force) revealed its highest values after a period of seven days. At this time the median value was 40 mN/mm. In the following period, a marked drop of the values was observed (19.8 mN/mm). With respect to the creep properties, we did not find any major changes over the period of six weeks. The median values were between 0.24 and 0.29 mm/mm. There were no significant differences between the samples seeded with chondrocytes and those which served as controls. A re-expansion of the samples was found with median values between 0.026 and 0.049 mm/mm (retardation). However, the original thickness was not reached after a period of 30 seconds with relief of the strain. Again, major differences of the values with respect to the duration of cultivation were not observed. Light microscopy revealed collagen type II and proteoglycans only in the pericellular region. CONCLUSION: In this study not all of the biomechanical properties of the cultivated tissue were investigated. The limitation of the tests to stiffness and viscoelastic properties was reasonable in view of a potential routine use. In addition, it may facilitate a comparison between different matrix systems. In our study, the cultivation of cells within the collagen matrix did not alter the mechanical properties of the scaffold.

[Reconstruction of extensive soft tissue loss by transplantation of dermal and epidermal equivalents]. / Rekonstruktion ausgedehnter Weichteilverluste durch Transplantation autologer dermaler und epidermaler Aquivalente.

AIM: The opportunities of autologous dermal and epidermal grafting as starting point for non-invasive reconstruction of extensive soft tissue defects will be demonstrated and discussed. METHODS: Skin biopsies for cell cultivation were taken from patients with extensive acute soft tissue defects of different origin. Cultured autologous fibroblasts grown on three dimensional biocompatible scaffolds made up of benzyl ester of hyaluronan were transplanted as "neo-dermis" on debrided and conditioned wound sites. After incorporation of the dermal equivalents grafting of subconfluent proliferative keratinocytes on hyaluronan based laser perforated membranes was performed. Ten days later a 0.2 mm thin, 1 : 6 meshed autograft to create definite biomechanical stability was overlaid. RESULTS: Grafting of in vitro cultured autologous fibroblasts revealed a good vascularized dermal tissue substitute. After keratinocyte-transfer formation of thin epithelium was visible. Final closure of the defects with aesthetic and normo-elastic tissue properties was achieved after thin mesh-grafting. CONCLUSIONS: Preliminary results seem to be very promising. Clinical follow-up as well as histological and immunohistochemical outcome in the treatment of five extensive soft-tissue defects are discussed. As in all fields of tissue engineering, long-tem studies and cost-benefit analyses are required.

[Heparin facilities proliferation of human osteoblasts in vitro]. / Heparin beschleunigt die Proliferation humaner Osteoblasten in vitro.

It is a well-known fact that long-term application of heparin can lead to osteoporosis. To learn more about the mechanisms of heparin-induced osteoporosis, we exposed human osteoblasts in vitro to heparin in various concentrations. We found an increased proliferation rate, especially in concentrations used therapeutically in humans (0.1-0.2 IU/ml). In our experiments fetal calf serum (FCS) was able to heighten the positive effect of heparin, showing a synergism between heparin and FCS.

[Modification of human osteoblasts by various analgesics]. / Beeinflussung humaner Osteoblasten durch verschiedene Analgetika.

Analgesia plays a major role in the therapy of fractures. This raises the question whether frequently used analgetics as Tramadol and Diclofenac have negative effects on the healing of fractures. Human osteoblasts were isolated from human spongiosa and incubated with Diclofenac, Tramadol and without analgetic substance in an in vitro experiment. After 9 days the absolute number of cells as a marker for proliferation and their mitochondrial activity were quantified. The mitochondrial activity was measured using the metabolisation of XTT (sodium-3'-(1-[phenylamino-carbonyl]-3,4-tetrazolium)-bis(4- methoxy-6-nitro) benzene-sulfonic acid hydrate). Both drugs led to a concentration-dependent decrease of cell proliferation. Tramadol showed a significant effect at a concentration of 20 micrograms/ml, which is much higher than the therapeutical concentration of 0.25 microgram/ml in serum. Diclofenac decreased cell proliferation at a concentration of 6 micrograms/ml, having a therapeutical concentration of 1.5 micrograms/ml in serum. Vitality of cells had constant correlation to absolute number of cells (R = 0.95). Our results don't suggest any negative effects of Tramadol on the osteoblast activities in vitro. Diclofenac significantly decreased the proliferation of human osteoblasts at concentrations probably reachable in vivo. A prolonged healing of fractures under treatment with Diclofenac may be possible in critical situations (pseudarthrosis revision, callus distraction).

[Psychological trauma in trauma medicine--the current status of psychological management of trauma victims in Germany]. / Psychotraumatologie in der Unfallmedizin--Zum Stand der psychischen Versorgung von Unfallopfern in Deutschland.

A clinically significant amount of accident victims display psychological disorders as a reaction to the trauma. Outcome studies on multiple trauma emphasize that life quality following severe accidental injury is influenced by early diagnosis and treatment of psychic co-morbidity. In a nationwide survey concerning the state of the art in in-patient treatment of injury patients conducted in Germany, every surgical ward was contacted and physicians were asked about their standard procedures of detecting and treating psychotraumatic complications. The results of the survey indicate that surgeons pay close attention to signs of psychological comorbidity and have good basic knowledge of psychotraumatic disorders. Nevertheless, there are structural deficiencies caused by the fact that only a few wards have staff specially trained in psychotraumatological care. Only a minority of patients is treated for psychotraumatic symptoms. In view of the high prevalence rates for psychotraumatic disorders in the aftermath of severe accidental injuries, the article discusses the need for psychic diagnosis and support as well as the necessary cooperative structures required in the model of Integrative Posttraumatic Acute Care.

[Cognitive deficits after polytrauma. Studies of quality of life]. / Kognitive Leistungsstörungen nach Polytrauma. Untersuchungen zur Lebensqualität.

The aim of this study was to quantify and compare the quality of life after multiple trauma for patients with and without posttraumatic cognitive achievement deficits. We examined 173 multiple trauma patients 2-6 years after their injury. The patients were asked to rate their quality of life according to the established measure scales Nottingham Health Profile, Spitzer Index, Everyday Life Questionnaire, to a visual analogue scale and to the new "revised Aachen Longterm Outcome Score" established in our hospital. To evaluate the cognitive achievement of each patient the "Kognitive Minimal Screening" (KMS) was applied. Statistical calculations result cognitive achievement deficits as a highly significant predictor for quality of life after multiple trauma. In spite of this, the craniocerebral trauma is no global predictor of posttraumatic quality of life. These results show that the quality of life after multiple trauma is not only influenced by approved predictors such as injury severity but also significantly by the presence of cognitive achievement deficits. The KMS seems to be an easy test to evaluate those cognitive deficits.

[Value of human recombinant osteogenetic proteins as bone replacement materials in lumbar spondylodesis. Results of an animal experiment study]. / Wertigkeit von rekombinantem humanem osteogenetischem Protein als Knochenersatzmaterial bei der lumbalen Spondylodese. Ergebnisse einer tierexperimentellen Untersuchung.

Up to now autologous spongiosa may be considered as the golden standard for the filling up of bone defects. Because of the limited quantity, complications at the extraction place and the increasing problems concerning infections when using homologous spongiosa the development of various bone replacement materials was intensified during the last years. The development of various osteogenetic proteins as well as experimental studies using these proteins represent a main point in science at present. It is expected that these substances will lead to a qualitative improvement and increase of bone healing. In the presented study influence of various osteogenetic substances to bone regeneration was examined at 30 breeding sheep after a ventral spine fusion of the segment L4/L5 by a dorsal approach. Bone defect filling was realized at each 10 animals with autologous spongiosa, Bio-Oss as well as the osteogenetic protein 1 (OP-1). To evaluate the progress and outcome of the segmental fusion during a post-operative period of 24 weeks x-ray controls were performed. In the 24th postoperative week after euthanasia of the experimental animals x-ray controls as well as computed and magnetic resonance tomographies were carried out. The results of 26 experimental animals could be analysed. The results were evaluated according to the criterias of an own score-system. Compared with autologous spongiosa OP-1 as a biomaterial for the fusion of spine-sections led to favorable radiologic results because of higher score values concerning the capability of fusion. Our experiences with Bio-Oss demonstrated lower osteogenetic potency after defect filling with this substance. Therefore we cannot recommend Bio-Oss as filling material for the fusion in spine surgery.

Aesthetic and functional results of harvesting radial forearm flap, especially with regard to hand function.

There is controversy in the literature regarding donor site morbidity following radial forearm flap harvesting. The aim of this study was to verify possible functional and aesthetic impairments at the donor site. Thirty-five patients who underwent maxillofacial reconstruction using radial forearm flap were asked to give their subjective assessment of the aesthetic outcome at the donor site and of postoperative hand function. They were also examined for trophic status; cold intolerance and tactile sensitivity of split-thickness skin graft, palm and finger pads; grip strength and finger-to-thumb pinch strength; range of movement for the wrist and finger joints; as well as functional hand testing. Slight impairments regarding hand strength and mobility were observed. However, due to their small extent they were of no clinical relevance, as shown by 85.7% of our patients displaying optimal functional hand testing values (80-100%), and 88.6% giving a positive subjective assessment (80-100%) of postoperative vs preoperative hand function. The results show that donor site morbidity following radial forearm flap harvesting is low.

[Treatment outcome after primary hemi-alloarthroplasty in dislocated humeral head fractures]. / Behandlungsergebnisse nach primärer Hemialloarthroplastik bei dislozierten Humeruskopffrakturen.

Humeral head fractures often lead to a high complication rate because of vulnerable vascularization of the humeral head, pretraumatical soft tissue lesions and osteoporotic bone. Compared with open reduction and internal fixation primary hemiarthroplasty seems to be an encouraging alternative treatment in case of dislocated and comminuted fractures. To evaluate our results following primary hemiarthroplasty we examined the outcome of 27 patients treated between November 1993 and May 1997 by primary hemiarthroplasty (15 Neer II, 12 Aequalis) in our institution within two weeks after trauma. The average patient follow-up was 3.5 years. Postoperatively more than 80% of the patients reported no pain. Excellent or good results with abduction over 90 degrees, low or moderate loss of power and low restraint in activities of all day living were achieved in about 50% of patients. The results according to the criteria of the Constant-Score depended on the intensity of the rehabilitation programme with an average outcome of 65 points. Maybe in the future functional results can be improved by a more aggressive rehabilitation and stronger rotator cuff refixation.

[Determinants of the global quality of life after polytrauma]. / Determinanten der globalen Lebensqualität nach Polytrauma.

This study investigated multiple trauma patients, who were injured between 1991 and 1995 and treated in our department. The aim of this study was to identify the determinants of quality of life after multiple trauma. From a total of 186 patients 173 (93%) were examined. The patients were asked to rate their quality of life according to the Nottingham Health Profile (NHP) and to a visual analogue scale (VAS). The VAS and the NHP isolated the age of the patients, the duration of artificial respiration, and the duration of rehabilitation as the predictors for a reduced overall quality of life. These results show that quality of life after multiple trauma not only depends on the severity of injury but also on demographic and psychosocial factors.

Multiple trauma in children patterns of injury--treatment strategy--outcome.

TOPIC OF THE STUDY: In 1994 more than 50,000 children under 15 years were involved in a road accident in Germany. About one third of them received major injuries and 431 children died. These data obviously show the importance of multiple trauma in children in a developed country. METHODS: Between 1985 and 1990, 64 multi-traumatized children were evaluated after receiving treatment at the Aachen University Hospital. It was possible to evaluate 66% of the patients at the follow-up examination after 1 and 5 years. The results have been measured with the ALOS (Aachen long-term outcome score) and the GOS (Glasgow outcome score) in relation to the degree of trauma. OWN RESULTS: 12.5% died mainly from the effects of a cerebral injury. 25% developed different complications. Again the effects of craniocerebral trauma determined the long-term outcome. All other injuries can be managed by aggressive treatment without major consequences. CONCLUSIONS: In multi-traumatized children, craniocerebral trauma is the key injury regarding both lethality and long-term outcome. Therefore, prevention is of primary importance. Aggressive treatment of thoracic and abdominal trauma can usually help to cure completely these injuries. Especially osteosynthetic procedures, exerting little strain and performed as appropriate for children, have made injuries of the limbs less critical.