Andreas Wentzensen

Computer-assistierte perkutane Verschraubung des hinteren Beckenrings Erste Erfahrungen mit einem Bildwandler basierten optoelektronischen Navigationssystem

ZusammenfassungBei Verletzungen des Beckenrings mit kombinierter vorderer und hinterer Instabilität, Typ C nach der AO Klassifikation, ist sowohl die Stabilisierung des vorderen als auch des hinteren Beckenrings indiziert. Bei alleiniger Beteiligung der Bandverbindungen stellt die transileosacrale Schraubenosteosynthese eine biomechanisch günstige, gering invasive Methode dar. Die Probleme dieser Methode liegen in der korrekten Schraubenplatzierung. Die Schraubenposition muss intraoperativ in 3 Ebenen kontrolliert werden (Inletview, Outletview und lateral). Daher ist die konventionelle Technik in der Regel mit einer hohen intraoperativen Strahlenexposition verbunden.In der vorliegenden Arbeit wird die Technik der exakten transileosacralen Schraubenplatzierung mit einem passiven optoelektronischen Navigationssystem, basiert auf Bildverstärkerdaten, gezeigt. In das System ist ein präkalibrierter navigierter Bildverstärker implementiert. Nach dem Anbringen der Referenzbasis am Patienten werden BV-Bilder in inlet-, outlet- und lateraler Projektion aufgenommen und in den Navigationsrechner geladen. Diese werden unter Verwendung eines speziellen mathematischen Algorithmus entzerrt. Anschließend kann die Schraubenplatzierung mit kalibrierten Instrumenten erfolgen. Die Instrumente werden in den BV-Bildern in bis zu 4 Ebenen gleichzeitig visualisiert, was der Situation des Einsatzes von 4 Bildverstärkern im konstanten Modus entsprechen würde. Somit ist keine weitere BV-Zeit ist erforderlich. Nach erfolgten Repositionsmanövern können bei entsprechender Veränderung der Anatomie intraoperativ neue Bilder zur Navigation aufgenommen werden.Aufgrund der unmittelbaren intraoperativen Verfügbarkeit und dem jederzeit möglichen Positionsupdate wenden wir die bildwandlergestützte Navigation bei frischen Verletzungen an. Zwischen Oktober 1999 und Dezember 2000 wurde bei 7 Patienten mit traumatischer Instabilität eine computerassistierte, perkutane, transileosacrale Verschraubung des hinteren Beckenrings durchgeführt. In allen Fällen erfolgte die Verschraubung des IS-Gelenkes mit 2 kanülierten AO 7,3 mm Titanschrauben. Postoperativ wurde die die Implantatlage im CT kontrolliert. Die Position wurde mit den intraoperativ erstellten Protokollen verglichen. Bei keinem Patienten trat eine Infektion auf. Postoperativ wurden keine neurologischen Ausfälle festgestellt. In der postoperativ durchgeführten Computertomographie ließ sich keine Fehlplatzierung intraspinal oder intraforaminal nachweisen. In 2 Fällen trat eine tangentiale Penetration des Schraubengewindes an der ventralen Sakrumbegrenzung auf.Die hier vorgestellten ersten Erfahrungen zeigen Vorteile bei der klinischen Anwendung eines bildwandlergestützten optoelektronischen Freihandnavigationssystems zur Platzierung iliosakraler Schrauben.AbstractInjuries 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 intraforaminal 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.

Cigarette smoking decreases TGF-β1 serum concentrations after long bone fracture

TGF-b1 serum concentrations are considered to be one of the most promising markers of fracture healing. Previously, we demonstrated significant differences in the post-traumatic time courses of patients with timely and delayed fracture healing. The aim of this study was to evaluate possible differences in the serum concentrations of TGF-b1 in cigarette-smoking vs. non-smoking patients with timely and delayed fracture healing in order to understand pathophysiological pathways through which smoking impairs fracture healing.Serum samples were collected from 248 patients undergoing surgical treatment for long bone fractures within 1 year of surgery. Samples from 14 patients with atrophic-type delayed fracture healing were compared with 14 matched patients with normal bone healing. Each group included seven smokers and seven non-smokers. Post-operative serum concentrations were analysed at 1, 2, 4, 8, and 12 weeks as well as 1 year after surgery. The patients were monitored both clinically and radiologically for the entire duration of the study.All patients increased TGF-b1 serum concentrations after surgery. In patients with normal fracture healing, significantly higher TGF-b1 levels were observed in non-smokers (70 ng/ml) than in smokers(50 ng/ml) at the 4th week after surgery (p = 0.007). Also at the 4th week, in patients with delayed healing, significantly lower TGF-b1 levels were observed in smokers than in non-smokers (38 ng/ml vs.47 ng/ml, p = 0.021). However, no significant differences between non-smokers with delayed healing and smokers with normal healing (p = 0.151) were observed at the 4th week after surgery. TGF-b1 serum concentrations reached a plateau in all groups from the 6th to the 12th week after surgery, with a slight decrease observed in the final measurement taken 1 year after surgery.This study demonstrates that, after fracture, TGF-b1 serum concentrations are reduced by smoking,and this reduction is statistically significant during the 4th week after surgery. Our findings may help reveal the mechanism by which smoking impairs fracture healing. Furthermore, these results may help to establish a serological marker that predicts impaired fracture healing soon after the injury. Surgeons will not only be able to monitor the bone healing, but they will also be able to monitor the success of additional treatments such as ultrasound and bone morphologic proteins (BMPs).

Treatment of tibial shaft non-unions: bone morphogenetic proteins versus autologous bone graft

Fractures of the tibial shaft are likely to result in delayed union or non-union; 10-30% of these fractures will not heal properly and are commonly treated with autologous bone grafting. BMP-7 is a recombinant bone growth factor that can be applied locally as an alternative or in addition to autologous bone grafting, and this study aimed to compare the efficiency of the two procedures. From January 1995 to December 2002, 82 people with delayed union of a tibial fracture at least 4 months after primary stabilisation underwent autologous bone grafting. Successful healing was defined as radiological bony consolidation. Between May 2002 and June 2005, 26 similar cases were treated after the failure of the graft with local implantation of BMP-7, and were followed up for at least 1 year. Of the 82 people receiving autologous bone grafts only, 24 (28%) still had no signs of consolidation after 4 months and required revision surgery. Of the 26 people with BMP-7 implantation after failed graft, bony consolidation was seen after 4 months in 24 cases and only 2 (8%) required revision surgery. The BMP-7 group, although including more complicated cases, showed a significantly higher (p = 0.025) success rate compared with the group that did not receive BMP-7.

TRACP 5b and CTX as osteological markers of delayed fracture healing

Radiological studies are the standard method to monitor fracture healing but they do not allow a timely assessment of bone healing. Biochemical markers react rapidly to changes in bone metabolism during fracture healing and could be an additional tool to monitor this process. The goal of this study was to observe changes in serum biomarkers and evaluate the possible differences in the serum levels of tartrate-resistant acid phosphatase 5b (TRACP 5b), total N-terminal propeptide of type I collagen (PINP), bone-specific alkaline phosphatase (BAP), and C-terminal cross-linking telopeptide of type I collagen (CTX) in patients with normal and delayed fracture healing. Several serum samples were collected for one year after the surgical treatment of long bone fractures in 248 patients. From this large pool, 15 patients with atrophic nonunion were matched to 15 patients with normal bone healing. Post-operative changes in osteological markers were monitored during the 1st, 2nd, 4th, 8th, 12th and 52nd weeks. The patients were followed both clinically and radiologically for the entire one-year duration of the study. In the first week, the absolute values of CTX decreased significantly (p=0.0164) in cases of delayed fracture healing. The relative values of TRACP 5b were significantly decreased at weeks 4 (p=0.0066) and 8 (p=0.0043). BAP and PINP levels decreased in the first week followed by an increase, but there were no significant differences in the absolute or relative values during the healing process in both patient groups. For the first time, we have demonstrated changes in serum concentrations of TRACP 5b, PINP, BAP, and CTX during normal and delayed fracture healing. Characteristic changes in systemic TRACP 5b and CTX levels could reflect the initial process of successful fracture healing and may be used in clinical practice to monitor the healing process. Furthermore, it could be very important for determining the beneficial effects of additional treatments such as ultrasound or BMPs in clinical trials.

Computer-assisted LISS plate osteosynthesis of proximal tibia fractures: Feasibility study and first clinical results

Fluoroscopy is the most common tool for the intraoperative control of long-bone fracture reduction. Limitations of this technology include high radiation exposure for the patient and the surgical team, limited visual field, distorted images, and cumbersome verification of image updating. Fluoroscopy-based navigation systems partially address these limitations by allowing fluoroscopic images to be used for real-time surgical localization and instrument tracking. Existing fluoroscopy-based navigation systems are still limited as far as the virtual representation of true surgical reality is concerned. This article, for the first time, presents a reality-enhanced virtual fluoroscopy with radiation-free updates of in situ surgical fluoroscopic images to control metaphyseal fracture reduction. A virtual fluoroscopy is created using the projection properties of the fluoroscope; it allows the display of detailed three-dimensional (3D) geometric models of surgical tools and implants superimposed on the X-ray images. Starting from multiple registered fluoroscopy images, a virtual 3D cylinder model for each principal bone fragment is constructed. This spatial cylinder model not only supplies a 3D image of the fracture, but also allows effective fragment projection recovery from the fluoroscopic images and enables radiation-free updates of in situ surgical fluoroscopic images by non-linear interpolation and warping algorithms. Initial clinical experience was gained during four tibia fracture fixations that were treated by LISS (Less Invasive Stabilization System) osteosynthesis. In the cases operated on, after primary image acquisition, the image intensifier was replaced by the virtual reality system. In all cases, the procedure including fracture reduction and LISS osteosynthesis was performed entirely in virtual reality. A significant disadvantage was the unfamiliar operation of this prototype software and the need for an additional operator for the navigation system.

Torsionswinkelbestimmung nach Schaftfrakturen der unteren Extremität – klinische Relevanz und Meßmethoden

Summary. In the treatment of femoral and tibial fractures the frontal and sagittal planes are controlled and documented by conventional X-ray films. Computed tomography permits exact measurement of the coronal plane. Between June 1993 and December 1997, 161 computed tomographic measurements of femoral torsion and 55 of tibial torsion after shaft fracture were carried out. The results were analyzed in a clinical study. A CT examination was carried out if the clinical examination aroused suspicion of a difference in torsion. 28.5 % of the patients examined with femoral fractures and 23.8 % of those with tibial fractures had torsion differences of more than 20 °. Between June 1993 and June 1997, 30 corrective derotating osteotomies of the femur and 9 of the tibia were carried out.The average preoperative difference of torsion of the femur was 29 ° and of the tibia 25 °. After the operation the average femur difference was 7 ° and of the lower leg 6.5 °, which are inside normal physiological limits. The osteotomies were carried out in the metaphysis near the fracture. Additional corrections in other planes were necessary on the femur in 27 % and on the lower leg in 46 %. With the aim of avoiding torsion differences, or at least to recognize them at an early stage, CT measurements of torsion after osteosythetic treatment of fresh unilateral femur-shaft fractures were carried out in 49 patients between October 1996 and December 1997. The torsion measurements during the operations had to be carried out clinically. No sufficiently exact method of measurement is available in the operating room. Three patients with increased differences of 28 °, 26 ° or 19 ° had their osteosyntheses corrected. The measurements after correction were inside the normal spread.Zusammenfassung. Die Achsstellung nach Versorgung von Ober- und Unterschenkelfrakturen in der Frontal- und Sagittalebene wird im konventionellen Röntgenbild kontrolliert und dokumentiert. In der Horizontalebene ist eine genaue Bestimmung nur mit der Computertomographie möglich. In einer klinischen Studie wurden zwischen Juni 1993 und Dezember 1997 200 computertomographische Torsionsmessungen am Ober- und 80 am Unterschenkel nach Schaftfrakturen analysiert. Die Messungen erfolgten beim klinischen Verdacht auf das Vorliegen einer Torsionswinkeldifferenz. Am Oberschenkel wurden in 28,5 %, am Unterschenkel in 23,8 % aller untersuchten Patienten Torsionsdifferenzen von mehr als 20 ° festgestellt. Zwischen Juni 1993 und Juni 1997 wurden 30 derotierende Korrekturosteotomien am Femur und 9 an der Tibia vorgenommen. Die Torsionsdifferenz betrug am Oberschenkel präoperativ durchschnittlich 29,0 ° und am Unterschenkel 25,0 °. Die postoperativen Differenzen lagen am Oberschenkel durchschnittlich bei 7 °, am Unterschenkel durchschnittlich bei 6,5 ° und damit innerhalb der physiologischen Schwankungsbreite. Die Osteotomien erfolgten jeweils in den frakturnahen Metaphysen. Zusätzliche Korrekturen in anderen Ebenen erfolgten am Femur in 27 % und am Unterschenkel in 46 %. Mit dem Ziel, Torsionsdifferenzen zu vermeiden oder zumindest frühzeitig zu erkennen, erfolgte ab Oktober 1996 bei 49 Patienten die computertomographische Torsionsmessung nach osteosynthetischer Versorgung einer frischen unilateralen Femurschaftfraktur. Die Torsionsbestimmung erfolgte intraoperativ jeweils klinisch, da im Operationssaal eine apparative Meßmethode mit hinreichender Genauigkeit nicht zur Verfügung steht. Bei 3 Patienten mit relevanten Differenzen (28 °, 26 ° und 19 °) erfolgte die Korrektur der Osteosynthese. Die Messungen nach Korrektur waren im Bereich der Normalverteilung.

The Surgical Treatment of Unstable Distal Radius Fractures by Angle Stable Implants: A Multicenter Prospective Study

Objectives: The goal of this study is to document the 2-year outcome after surgical treatment of distal radius fractures using an angle stable implant. Design: Prospective case-series. Setting: Multicenter study in nine trauma units with recruitment between December 2001 and May 2003. Patients: One hundred eight patients with the same number of distal radius fractures. Intervention: Open reduction and internal fixation with the LCP DR 3.5 mm (Synthes GmbH, Oberdorf, Switzerland). Main Outcome Measurements: Disabilities of the Arm, Shoulder and Hand, Gartland and Werley, SF-36 scores, radiologic assessment, and return to work status at 2 years. Results: At 2 years, the mean range of motion (relative to the contralateral wrist) was 83% for palmar flexion, 91% for extension, 94% for radial deviation, 92% for ulnar deviation, and 98%/94% for pronation/supination angles. Grip strength was 90% of the mean uninjured side. The average radiographic measurements were 23.6° for radial inclination angle, 6.1° for palmar (volar) tilt angle, and 0 mm for ulnar variance. The proportion of fractures for which the Gartland and Werley score was categorized as either good or excellent was 89%. Minor complications occurred in 14 patients, although none of these events were considered to be directly related to the implant. Conclusion: After a 2-year follow-up period, the use of an angle stable implant for unstable distal radius fractures provides adequate fixation with minimal loss of reduction. This device is associated with good functional and radiologic outcome for the patient and is indicated for distal radius fractures classified as Orthopaedic Trauma Association (OTA) Type 23-A2/A3, OTA Type 23-B2/B3, and OTA Type 23-C.

Standardisierte Primärtherapie des polytraumatisierten Patienten

ZusammenfassungEinleitungEin standardisiertes Management verbessert die Behandlungsergebnisse von Schwerverletzten. Für Krankheitsbilder wie den Schlaganfall oder auch das akute Koronarsyndrom (AKS) sind feste Handlungsabläufe für die präklinische und erste klinische Versorgung etabliert. Die Behandlung kritischer Traumapatienten erfährt in der Präklinik sowie in der ersten klinischen Phase immer wieder unterschiedliche Abläufe. Aus den Analysen des Traumaregisters der DGU wissen wir, dass ein schwerverletzter Patient durchschnittlich 70 Minuten bis zur Klinikeinweisung auf der Straße verbringt. Dies gilt es zu verbessern. Durch Einführung des ATLS®-Programms in Deutschland 2003 konnte die erste klinische Phase bereits durch eine standardisierte Schulung verbessert werden. PHTLS® und ATLS® ergänzen sich.ErgebnisMit PHTLS® und ATLS® gibt es Ausbildungskonzepte, die ein standardisiertes, prioritätenorientiertes präklinisches und klinisches Traumamanagement lehren. Ziel ist es, zunächst den Patientenzustand schnell und genau einzuschätzen und so den „kritischen“ Patienten zu identifizieren. Außerdem ermöglichen die Konzepte die prioritätenorientierte Behandlung und erleichtern die Entscheidung, ob die Patienten präklinisch vor Ort weiterbehandelt werden können oder einen sofortigen Transport benötigen. Gleiches gilt für das Vorgehen im Schockraum. Über allem steht der Gedanke, Sekundärschäden zu vermeiden, die Zeit nicht aus den Augen zu verlieren und eine gleichbleibende Qualität der Versorgung zu sichern. Die Kurse vermitteln hierzu systematisches Wissen, Techniken, Fertigkeiten und Verhalten in Diagnostik und Therapie. Die Kurse richten sich an alle Fachrichtungen, welche an der Traumaversorgung beteiligt sind. Der Deutsche Berufsverband Rettungsdienst e.V. (DBRD) hat mit Unterstützung der Deutschen Gesellschaft für Unfallchirurgie (DGU) und der Deutschen Gesellschaft für Anästhesiologie und Intensivmedizin (DGAI) das PHTLS®-Kurssystem in Lizenz von der National Association of Emergency Medical Technician (NAEMT) und dem American College of Surgeons (ACS) übernommen und bietet es seit Ende 2007 in Deutschland an. ATLS® ist seit 2003 durch die DGU etabliert und stellt ein erfolgreiches und ebenso strukturiertes Schockraummanagement dar.SchlussfolgerungPHTLS® und ATLS® sind etablierte und standardisierte Konzepte, die regelmäßig überarbeitet und dem neuen medizinischen Wissensstand angepasst werden. Damit eröffnete sich die Möglichkeit, das präklinische und erste klinische Traumamanagement fach- und klinikübergreifend entsprechend zu standardisieren und eigene Erkenntnisse einzubringen.AbstractIntroductionStandardised management improves treatment results in seriously injured patients. For conditions like stroke or acute coronary syndrome (ACS) there are set treatment pathways which have been established for prehospital and primary hospital care. The treatment of critical trauma patients, however, follows varying procedures in both the prehospital and primary hospital phases. From an analysis of the trauma register of the German Society for Trauma Surgery (DGU), we know that a seriously injured patient remains on the road for 70 min on average before transferral to hospital. This requires improvement. With the 2003 introduction of the ATLS® programme in Germany, the initial clinical phase could be improved upon simply by means of standardised training. PHTLS® und ATLS® complement one another.ResultsPHTLS® und ATLS® represent training concepts which teach standardised, priority-based prehospital and hospital trauma management. The aim is to make an initial rapid and accurate assessment of the patient’s condition, thereby identifying the“critical” patient. The concepts also make priority-based treatment possible and facilitate decision-making as to whether patients can receive further on-the-spot treatment or whether immediate transport is necessary. The procedure is identical in the shock room. The primary consideration is to prevent secondary damage, not to lose track of time and to ensure consistent quality of care. The courses teach systematic knowledge, techniques, skills and conduct in diagnosis and therapy. The courses are oriented to all medical specialities associated with trauma care. With the support of the German Society for Trauma Surgery (DGU) and the German Society for Anesthesiology and Intensive Medicine (DGAI), the German Professional Organisation of Rescue Services (DBRD) has adopted the PHTLS® course system on licence from the National Association of Emergency Medical Technicians (NAEMT) and the American College of Surgeons (ACS) and has been offering it in Germany since late 2007. ATLS® was established by the DGU in 2003 and represents successful and similarly structured shock-room management.ConclusionPHTLS® und ATLS® are established and standardised concepts, which are constantly reviewed and updated according to the latest medical knowledge. They provide the opportunity to standardise prehospital and primary clinical trauma management for all specialties and hospitals, while incorporating own knowledge.

Comparison of angle stable plate fixation approaches for distal radius fractures

INTRODUCTION The aim of the study was to compare radiological and functional outcomes between volar and dorsal surgical fixation of distal radius fractures using low-profile, fixed-angle implants. PATIENTS AND METHODS A total of 305 distal radius fracture patients were treated with Synthes locking compression plate (LCP) 2.4- or 3.5-mm fixation using either a volar (n=266) or dorsal (n=39) approach. The patients were examined at 6 months, 1 and 2 years for radiological assessment of fracture healing, alignment, reduction and arthritis, as well as the determination of various functional outcome scores. RESULTS Both groups were comparable with respect to baseline and injury characteristics. The complication rate was higher for the volar approach (15%). No significant differences were observed for Disabilities of the Arm, Shoulder and Hand (DASH) and Short Form (36) Health Survey (SF-36) scores, pain, arthritis grade, grip strength and radiological measurements. However, a significantly better functional outcome represented by a low mean Gartland and Werley score was observed for the volar approach after 6 and 12 months. Significantly higher percentages of dorsal extension, palmar flexion, ulnar deviation and supination angle (relative to the mean contralateral healthy wrist) were also reported for volar approach patients at the 6-month follow-up. CONCLUSIONS Volar internal fixation of distal radius fractures with LCP DR implants can result in earlier and better functional outcome compared with the dorsal approach, yet is associated with a higher incidence of complications. After 2 years, these differences are no longer observed between the two surgical methods.

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.