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A Wentzensen

Publications and source records attributed to A Wentzensen.

At least 19 recordsLinked to original sources
PubMed2007

[TGF-beta1 as a pathophysiological factor in fracture healing].

AIM: TGF-beta1 is an important local and systemic regulatory molecule during fracture healing. Various authors have shown differences in the systemic levels of TGF-beta1 over the time taken for bone healing in distraction osteogenesis and osteotomies. Previous studies have shown characteristic differences in the physiological levels of growth factors between normal fracture healing and delayed fracture union. The aim of the present study was to evaluate possible differences in sera levels of patients with normal and delayed union fracture healing. METHODS: Patients with long bone shaft fractures were recruited prospectively. Peripheral blood samples were collected over a period of 1 year using a standardized time schedule. At the end of the individual's investigation period, TGF-beta1 levels were determined. To achieve a homogeneous collective of patients, only those with a maximum of two fractures were included in the study. After matching for four criteria, we compared patients with normal fracture healing to patients with delayed unions. The fact of delayed union was accepted in case of failed consolidation 4 months after trauma. RESULTS: During a prospective study period of 1 year, 15 patients with normal fracture healing could be compared to 15 patients suffering from delayed union. By determining the absolute sera levels we found a typical increase of TGF-beta1 up to 2 weeks after fracture in both groups, with a subsequent decrease up to the sixth week after fracture. However, a decline in serum concentration occurred earlier in patients with delayed union, causing significantly lower TGF-beta1 levels in the non-union group 4 weeks after trauma (P=0.00006). CONCLUSION: Even with a relatively small number of patients, we could show a significant difference in serum concentrations of TGF-beta1 between the investigated groups. If these results can be verified within a larger collective, TGF-beta1 could be used as a predictive cytokine for delayed fracture healing.

Adult↗
PubMed2006

[Trauma centers in Germany. Status report].

BACKGROUND: In Germany, a total of more than 30,000 polytraumatized patients are treated in level I-IV trauma centers. The exact number of hospitals fulfilling the requirements for the treatment of severely injured patients is unknown. We analyzed the number of hospitals in Germany capable of managing polytraumatized patients. We further analyzed the influence of various geographic and infrastructure conditions on the management of severely injured patients in the various Federal States in Germany. METHODS: First we conducted a nationwide research of all hospitals specialized in trauma management. Points of interest were structural and personnel requirements. These data were compared to the data obtained by the Federal Statistical Office. With a special software program we were able to conduct for the first time a geographic visualization of all trauma hospitals. RESULTS: There are 108 level I trauma centers, 209 level II trauma centers, and 431 level III and IV trauma centers in Germany. The geographic concentration of hospitals fulfilling the requirements for the treatment of severely injured patients differs regionally. There is an obvious correlation between trauma deaths and a low hospital concentration and less developed infrastructure. CONCLUSION: Objectively, the number of trauma centers for the treatment of severely injured patients seems to be adequate in Germany. Nevertheless, there are substantial differences between various Federal States in Germany concerning the distribution of hospitals as well as the geographic and infrastructure conditions. To optimize trauma management in Germany we think that the formation of regional trauma networks is mandatory.

Accidents, Traffic↗
PubMed2006

[Clinical experience with bone morphogenetic protein 7 (BMP 7) in nonunions of long bones].

BACKGROUND: Nonunions of long bone fractures are considerable therapeutic and economic problems with increasing tendency. Basic surgical options are autogenous cancellous bone grafting, rod dynamization, reamed nailing, plate fixation with compression, and bone transport techniques. If these methods fail to work, alternative treatment options are needed. MATERIAL AND METHODS: Since May 2001 treatment with recombinant human (rh) bone morphogenic protein 7 [BMP-7 or osteogenic protein 1 (OP-1)] in combination with a type one collagen carrier has gained interest. BMP 7 induces the formation of new bone by differentiation of stem cells, thereby initiating the reaction cascade of osteogenesis. Nonunions over 9 months and unsuccessful bone grafting delineate the indication. RESULTS: We report our experience with 21 patients and nonunion of long bone fractures. Between July 2002 and June 2004, 23 units of BMP 7 were implanted. The implantation sites were 7 femora, 12 tibias, 2 humeri, and 2 forearms. In ten cases BMP 7 was combined with a new osteosynthesis and bone grafting and in five patients with bone grafting alone. In contrast in eight patients BMP 7 was applied as a single procedure without any bone grafting or any change of the osteosynthesis. CONCLUSION: There were no peri- or postoperative complications. Follow-up was obtained for a minimum of 6 months. Of 23 implantations, 22 were successful with bony healing revealed by clinical and radiological evaluation. In one patient no bony consolidation of the nonunion has been seen so far. In summary, based on our results we propose BMP 7 as an additional innovative therapy of long bone nonunions.

Adult↗
PubMed2006

[Implant-associated post-traumatic osteomyelitis. Bacterial biofilms and the immune defence as protagonists of the local inflammatory process].

BACKGROUND: Formation of bacterial biofilms on implants is a severe complication following orthopaedic surgery. In the present study we addressed the role of the immune response, particularly with regard to the pathogenesis of the disease. METHODS: In a prospective study comprising 74 patients with implant-associated post-traumatic osteomyelitis, peripheral blood cells as well as cells recovered from the infected site during surgery were characterised phenotypically and functionally. RESULTS: We found massive infiltration of polymorphonuclear neutrophils (PMN), which were highly activated, particularly regarding their bactericidal potential, such as increased production of superoxides and upregulation of activation-associated surface receptors. CONCLUSION: PMN are activated in response to the implant-associated osteomyelitis; they also infiltrate the infected tissue, but cannot control the infection. By release of their cytotoxic entities they could contribute to tissue destruction and eventually to osteolysis.

Adolescent↗
PubMed2006

Cellular inflammatory response to persistent localized Staphylococcus aureus infection: phenotypical and functional characterization of polymorphonuclear neutrophils (PMN).

Persistent, localized Staphylococcus aureus infections, refractory to antibiotic treatment, can result in massive tissue destruction and surgical intervention is often the only therapeutic option. In that context, we investigated patients with S. aureus-induced infection at various sites, apparent as either olecranon bursitis, empyema of the knee joint or soft tissue abscess formation. As expected, a prominent leucocyte infiltrate was found, consisting predominantly of polymorphonuclear neutrophils (PMN) (up to 75%) and to a lesser extent of T lymphocytes and natural killer (NK) cells. In line with their bactericidal capacity, PMN expressed the high-affinity receptor for IgG, CD64 and the lipopolysaccharide (LPS) receptor CD14; moreover, the oxygen radical production in response to the bacterial peptide f-MLP was enhanced, while chemotactic activity was greatly reduced. The more intriguing finding, however, was that a portion of PMN had acquired major histocompatibility complex (MHC) class II antigens and CD83, indicative of a transdifferentiation of PMN to cells with dendritic-like characteristics. Of note is that a similar transdifferentiation can be induced in PMN in vitro, e.g. by gamma interferon or by tumour necrosis factor alpha. Co-cultivation of transdifferentiated PMN with autologous T lymphocytes resulted in prominent T cell proliferation, provided that S. aureus enterotoxin A was added. Taken together, persistent S. aureus infection induces PMN to acquire characteristics of dendritic cells, which in turn might promote the local immune response.

Aged↗
PubMed2005

Stiffness measurement of the neocallus with the Fraktometer FM 100.

INTRODUCTION: The assessment of fracture healing is subjective, and neither radiology nor manual examination allows a reliable determination of bone healing. Fracture healing control in the treatment of tibia shaft fracture with external fixator by a stiffness measurement system (Fraktometer FM 100) is known from clinical studies. The purpose of this study was to follow stiffness control at external fixator in healing of callotasis with the stiffness measurement system. MATERIALS AND METHODS: From 1994 to 1997 stiffness measurements with the described system (Fraktometer FM 100) were performed in the BG-Clinic Ludwigshafen to assess the healing course in 11 cases of callotasis at lower limb. RESULTS: In ten cases, regular healing could be followed by signal decrease; in one case, a persistent signal without tendency to decrease was able to reveal callotasis failure at an early point of time. The investigation could also show the importance of bending stiffness control. One case of late axis deformation after fixator removal occurred because of disregarding delayed bending signal decrease. CONCLUSION: Measurements of the external fixator's stiffness after callotasis can provide useful additional information for further treatment strategy.

Adult↗
PubMed2005

Unstable diaphyseal fractures of both bones of the forearm in children: plate fixation versus intramedullary nailing.

This retrospective study evaluated the results of plating versus intramedullary fixation in the management of unstable, diaphyseal fractures of both bones of the forearm in children. Of the 64 children included, 45 were treated with intramedullary fixation, 19 with plating. Only A3 forearm fractures of the middle third or the transition zones were included; Galeazzi, Monteggia, and Greenstick fractures were excluded. Full radiological follow-up to union was obtained in all cases and 60 patients returned for clinical evaluation 32.3 months (plating) and 20.6 months (intramedullary fixation) after injury. The functional outcome did not differ significantly. In the intramedullary fixation group, we found two major complications (refracture and non-union) and nine minor complications (two delayed unions, three thumb neuropathies, two rod migrations, two skin infections). In the plate group, there were two major complications (refractures) and one minor complication (thumb neuropathy). Plating resulted in significantly worse results for surgical approach, operating times, frequency and duration of hospitalisation, and cosmetic outcome. In conclusion, intramedullary fixation of an unstable forearm fracture in skeletally immature patients is a safe, child-friendly, minimally invasive technique that allows early functional treatment with an excellent functional and cosmetic outcome.

Adolescent↗
PubMed2005

TGF-beta1 as a marker of delayed fracture healing.

Mitogens of the TGF-beta superfamily have been shown to be crucial local and systemic regulatory molecules involved in fracture healing. However, there exists only little information about systemic regulation of bone regeneration by growth factors and no reports comparing serum levels of bone growth factors between normal and failed fracture healing have been published so far. We hypothesized that quality of fracture healing might be reflected by systemic alterations of key regulatory growth factors involved in bone formation and remodeling. Therefore, the aim of this study was to evaluate possible differences in serum levels of BMP-2, BMP-4, and TGF-beta1 in patients with normal and delayed fracture healing. 103 patients with diaphyseal fractures of long bones were recruited prospectively. Peripheral blood samples were collected over a period of 6 months following a standardized time schedule. At the end of the individual investigation period, growth factor serum levels were measured using commercially available enzyme immunoassays. For the elimination of disturbing influences, patients in both groups were matched by gender, age, fracture type, and localization as well as applied technique of osteosynthesis. During a study period of 1 year, 10 patients with an atrophic type of delayed union could be retrieved and matched to 10 patients with normal fracture healing. The diagnosis of delayed union was assumed in case of failed consolidation 4 months after trauma. We found an increase of TGF-beta1 serum levels up to 2 weeks after fracture in both groups with a following return to the reference value within 6 weeks after trauma. However, decline of serum concentration occurred earlier in patients with delayed fracture healing. At 4 weeks after trauma, serum levels of TGF-beta1 were significantly lower in patients of the delayed union group. Serum levels of BMP-2 and BMP-4 were below detection level in all patients, respectively. These findings support the critical role of TGF-beta1 in fracture healing. Events during the consolidation phase seem to be dependent on sufficient availability of TGF-beta1.

Biomarkers↗
PubMed2004

[Intraoperative three-dimensional navigation for pedicle screw placement].

The mobile SIREMOBIL Iso-C(3D) C-arm (Siemens, Erlangen, Germany) is the first device permitting intraoperative, three-dimensional representation of bone structures. A high-resolution, isotropic 3D data cube in the isocenter with sides of approximately 12 cm is calculated simultaneously. The SIREMOBIL Iso-C(3D) is linked to the navigation system. This makes it possible to transfer the generated 3D data directly to the linked navigation system without the need for surgeon-dependent registration. In this prospective clinical trial, we evaluated the accuracy of pedicle screw placement using this device. In 61 patients, a total of 302 pedicle screws were placed. Only in five cases (1.7%) were misplacements of > or =2 mm shown in postoperative control CT. The average fluoroscopy time was 1.28+/-0.56 min, and the average operative duration was 103.26+/-23.3 min. There were no postoperative neurological complications in any of the 30 patients. From these data, we conclude that Iso-C(3D) navigation is a very accurate method for the placement of pedicle screws.

Adolescent↗
PubMed2004

[Postoperative and bacterial osteitis. New possibilities for therapy].

Current therapy concepts for post-trauma osteitis include radical debridement, stabilization of bone and soft tissue care using early flap transfers. With this more radical approach, the long term results are improved, however, total treatment time still is very long. In addition to the physical, mental and social consequences for the patient, treatment costs are also very high. Antibiotic therapy as an adjuvant is still standard and effective although the development of worldwide antibiotic resistance has increased treatment difficulties. One of the main aims of research is to reduce these problems or to prevent the development of osteitis entirely. However, research has not yet elucidated the complex immunologic changes involved. In addition, most results are obtained from animal studies and clinical investigations are required.

Anti-Bacterial Agents↗
PubMed2004

Five years' clinical experience with the unreamed humeral nail in the treatment of humeral shaft fractures.

With the development of interlocking nail systems especially designed for the upper arm, standards for the operative treatment of humeral shaft fractures have appeared to change. The trumpet-like shape of the medullary cavity does not allow stable splinting with a nail alone, and therefore the bone--nail complex is commonly stabilized with interlocking bolts. Between June 1996 and June 2001, 51 fractures of the humeral shaft were treated operatively at the BG Unfallklinik Ludwigshafen with the unreamed humeral nail (UHN; Synthes). All nails were inserted by the retrograde technique. Ninety-five percent of the patients showed excellent or good shoulder function at follow-up examinations. For elbow function, 91.4% of the patients showed excellent or good results. Three out of four patients with poor elbow function had suffered from an additional injury to the brachial plexus; one patient developed heterotopic ossification. Intraoperative complications were: one iatrogenic lesion of the radial nerve, two intraoperative shaft fractures, one split at the insertion point, and one supracondylar fracture. As implants we used 7.5 mm nails in 36 cases and 6.7 mm nails in 15 cases. Among the 47 patients undergoing follow-up examinations, we found two cases of non-union. All patients were pain-free. Thirty-seven patients were very satisfied, six satisfied and four dissatisfied with the therapy. Decisive criteria for the use of a new implant are a high safety standard and simple reproducibility; these appear to be fulfilled by retrograde nailing of humeral fractures with the UHN. Interlocking nailing with the UHN enriches the range of therapeutic options for humeral shaft fractures.

Adolescent↗
PubMed2003

[Comparative examination between an angle stable, monokortikal osteosynthesis technique with the conventional plate osteosynthesis at the anterior arm shaft fracture].

With a retrospective Follow-up essay under the use of Matched peer variables the wellbeing course was examined by patient pairs (128 patients) assigned to 64 individually with fractures of the anterior arm shaft. A group which treats others with 2.7 or 3.5 mm DCP/LC-DCP got with the AO Point Contact basic gate (PC-Fix). The well-being course data count after the implantation on a period of 18 months. The Follow-up-rate was 100% for this time period. The patients became for each other on reason of the criteria: assigned to fracture classification, soft partial loss, accompanying injuries and age. Possible complications were: implantation conditional nerve damages, infections, implant failures, delayed healings, pseudarthroses, motion reductions and synostoses. Complications appeared (PC-Fix at 13 patients: respect, DCP: 5). The statistical testing didn't yield any statistically significant advantage for one for the two implants at a p-value of 0.5811 for.

Adult↗
PubMed2003

[CT-free image guided acetabulum navigation in clinical routine].

After experimental and preclinical evaluation (HAP Paul Award 2001) of the CT-free image-guided surgical navigation system for acetabular cup placement (SurgiGATE C-arm cup" by Medivision, Switzerland), the system was introduced into clinical routine. The computation of the angular orientation of the cup is based on reference coordinates from the anterior pelvic plane concept. A hybrid strategy for pelvic landmark acquisition has been introduced involving percutaneous pointer-based digitization with the noninvasive biplanar landmark reconstruction using multiple registered fluoroscopy images. From January 2001 to December 2002, a total of 256 consecutive patients with primary osteoarthrosis (mean age 69 years, 161 male, 95 female, 132 left, and 124 right hip joints) were operated on with the hybrid CT-free navigation system. During each operation the angular orientation of the inserted implant was recorded. To determine the placement accuracy of the acetabular components, 50 consecutive patients underwent a CT scan 7-10 days postoperatively to analyze the cup position related to the anterior pelvic plane. This was all done blinded by the same investigator with the planning software of the CT-based navigation system of Medivision. There was no significant learning curve observed for the use of the system. The mean value for postoperative inclination was 43 degrees (SD 3.0, range: 37 degrees -49 degrees ) and for anteversion 19 degrees (SD 3.9, range: 10 degrees -28 degrees ). The resulting system accuracy, i.e., the difference between intraoperatively calculated cup orientation and postoperatively measured implant position showed a mean error of 1.5 degrees for the inclination (maximum 5 degrees, SD 1.1) and 2.4 degrees for the anteversion (maximum 6 degrees, SD 1.3). An accuracy of better than 5 degrees inclination and 6 degrees anteversion was achieved under clinical conditions, which implies that there is no significant difference in performance from the established CT-based navigation methods. Image-guided CT-free cup navigation provides a reliable solution for future THA.

Acetabulum↗
PubMed2003

[Iso-C(3D0-assisted) navigated implantation of pedicle screws in thoracic lumbar vertebrae].

The mobile Siremobil Iso-C(3D) C-arm (Siemens AG, Medical Solutions, Erlangen) is the first device that permits the intraoperative three-dimensional (3D) representation of bone structures. A high-resolution isotropic 3D data cube in the isocenter with an edge length of approximately 12 cm is calculated simultaneously. The Siremobil Iso-C(3D) is linked to navigation with the integrated NaviLink interface (Siemens AG, Medical Solutions, Erlangen). This makes it possible to transfer the generated 3D data directly to the linked navigation system Surgigate (Medivision, Oberndorf, Switzerland). In this prospective clinical trial we evaluated the accuracy of pedicle screw placement using the Siremobil Iso-C(3D) C-arm. The results were compared to the conventional approach and other computer-assisted procedures (CT-based navigation, C-arm-based 2D navigation) in historical control groups. A total of 141 pedicle screws were placed in 30 patients (70 thoracic spine, 71 lumbar spine). Only in one single case was misplacement shown in the postoperative control CT scan (0.71%), the lowest rate of incorrect placements of all techniques. Also the lowest average fluoroscopy time (1.28+/-0.56 min) was achieved during the placement of pedicle screws on the spine with Iso-C(3D) navigation at a comparable average OR duration (103.26+/-23.3 min). There were no postoperative neurological complications in all 30 patients. From these data we conclude that Iso-C(3D) navigation of pedicle screws is a very accurate method in the correct placement of pedicle screws.

Bone Screws↗
PubMed2002

Monitoring and healing analysis of 100 tibial shaft fractures.

BACKGROUND: We assessed the value of measuring biomechanical stiffness by assessing the fixator's external deformation as an objective means for monitoring fracture healing and determining the postoperative treatment regime, as compared to clinical and radiographic means of evaluation. PATIENTS AND METHODS: One hundred patients with tibial shaft fractures managed by unilateral external fixation had their fracture stiffness monitored. Stiffness was measured and clinical and radiological examinations were performed every 3-4 weeks. RESULTS: The time required for healing as indicated by stiffness measurement was an average of 2.5 weeks earlier than by radiological assessment. Eighty-two patients healed within 19 weeks (12.1+/-3.3 weeks) and ten patients in the following 6 weeks (24+/-4.3 weeks). Eight patients did not show an increase in fracture stiffness and received intramedullary nailing at a second operation. The average healing time was 11.3+/-4 weeks for type A, 13.1+/-3.6 weeks for type B fractures, and 15.1+/-5.9 weeks for type C fractures. The healing time for closed fractures was 11.3+/-3.2 weeks and for open fractures 14+/-4.9 weeks. CONCLUSIONS: The measurement of fracture stiffness allows the detection of patients at risk for nonunions. The healing time increased with increasing fracture gap size and was less in patients with younger age, less complex fractures, and lesser degrees of soft tissue damage.

Adolescent↗
PubMed2002

[Computer-assisted screw osteosynthesis of the posterior pelvic ring. Initial experiences with an image reconstruction based optoelectronic navigation system].

Injuries of the posterior pelvic with combined anterior and posterior instability require the stabilisation of both the anterior and posterior pelvic ring. If the injury only involves the ligamental connections, then a transileosacral osteosynthesis with screws is the minimal invasive and biomechanically suitable method of choice. The difficulty with this approach is the correct placement of the screws. Their position must be monitored intraoperatively in 3 planes (inlet, outlet and lateral viewing). This denotes that conventional methods involve high radiation dosages for the patient and the surgical staff. Having the system readily available and being able to perform updates during the operation, fluoroscopically supported navigation for the treatment of fresh injuries becomes possible. Between October 1999 and December 2000 7 patients with traumatic instability of the posterior pelvic ring were treated by computer assisted percutaneous transileosacral screw osteosynthesis. In each case the osteosynthesis of the ileosacral joint was performed with two cannulated AO 7.3 mm titanium screws. After the operation the screw position was controlled by CT scanning and compared to the data acquired intraoperatively. No patients had infection, and there were no postoperative neurological defects. The postoperative CT scans showed no intraspinal or intraforminal malplacement of the screws. In two cases a slight tangential screwthread penetration through the ventral sacrum was found. Our first experiences with this novel technology are encouraging and clearly demonstrate the advantages of fluoroscopic supported passive navigation systems for the optimal placement of ileosacral screws.

Adolescent↗
PubMed2002

[Quality of life after acetabulum and pelvic ring fractures. Correlation of long-term results with the "Injury Severity Score" (ISS)].

Patients with acetabular (AF) and pelvic ring fractures (BrF) make heavy demands on hospital resources and face difficulties in rehabilitation. From the patients' point of view, milestones in recovery are quality of life and return to productivity. We studied 42 patients with acetabular and 64 patients with pelvic ring fractures over a period of 10 years. The average follow-up took place 4 years after discharge. The injury severity score (ISS) did not correlate to long-term disability and quality of life (QoL) based on the Rosser index, data on return to productivity, or to radiological and clinical outcome. This study emphasizes the need for new injury scoring systems that better predict the recovery and ability to return to work of trauma patients after surviving pelvic fractures. Proper follow-up evaluations should analyze the patients' quality of life and working activity beside traditional items such as radiological and clinical findings.

Acetabulum↗