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Hintergrund: 3D-fähige Röntgenbildverstärker (BV) ermöglichen über die Anfertigung von Multiplanaren Rekonstruktionen (MPR) eine intraoperative Lagekontrolle von Pedikelschrauben in verschiedenen Betrachtungsebenen. Durch solch einen 3D-Scan können Schraubenfehllagen noch im Operationssaal diagnostiziert und korrigiert werden, die sonst unter Umständen erst in einer postoperativen Computertomografie (CT) erkennbar wären. Ziel: Es sollte geprüft werden, ob die Bildqualität des Vision RFD 3D Bildverstärkers der Firma Ziehm ausreicht, um die Pedikelschraubenlage intraoperativ korrekt einzuschätzen, und wie effizient sich der 3D-Scan in den Operationsablauf integrieren lässt. Methodik: Es handelt sich um eine retrospektive Auswertung von 12 Patientendatensätzen, bei welchen im Rahmen einer Operation (OP) zur Pedikelschraubenimplantation ein intraoperativer 3D- und ein postoperativer CT-Bilddatensatz vorlagen. 62 Pedikelschrauben waren im Kollektiv vorhanden. Die Evaluation der Bildqualität erfolgte durch den Vergleich des 3D-Scans zur CT, welche als Goldstandard festgelegt wurde. Jede Pedikelschraube wurde jeweils zweimal von zwei Untersuchern mit unterschiedlichem Erfahrungsgrad in der intraoperativen 3D-Bildgebung befundet. Outcome-Parameter bildeten die Schraubenlage in Relation zur knöchernen Kortikalis (2mm-Intervallskala) und die subjektive Bewertung der Artefaktbildung (5-teilige Likert-Skala). Zur statistischen Auswertung wurden Kappa-Korrelationskoeffizienten nach Cohen (κ) berechnet und die Inter- und Intraobserver-Reliabilitäten kontrolliert. Damit wurde überprüft, inwieweit die Einschätzung der Schraubenlage und der Artefaktbildung im 3D-Scan mit der in der CT übereinstimmten. Die Praktikabilität wurde anhand perioperativ erhobener Daten, Anwenderfragebögen und Lernkurvenstudien beschrieben. Ergebnisse: Auf Grundlage des 3D-Scans wurden fünf von 44 de-novo implantierten Pedikelschrauben intraoperativ revidiert (11,4%). Es wurden keine sekundären Revisionsperationen auf Basis der postoperativen CT indiziert. Bezüglich der Einschätzung der Schraubenlage ergab sich eine hohe Übereinstimmung des 3D-Scans mit der CT (κ = 0.79 [0.70 – 0.89]; p < 0.001). Die Übereinstimmung war im Fall des erfahrenen Untersuchers (κ = 0.88 [0.77 – 0.99]; p < 0.001) signifikant höher als im Fall des unerfahrenen Untersuchers (κ = 0.69 [0.53 – 0.86]; p < 0.001). Die Interobserver-Reliabilität war in der CT (κ = 0.72 [0.57 – 0.87]; p < 0.0001) signifikant höher als im 3D-Scan (κ = 0.55 [0.38 – 0.72]; p < 0.0001). Die Intraobserver-Reliabilität war insgesamt bei beiden Untersuchern exzellent (erfahrener Untersucher: κ = 0.86 [0.76 – 1] ; unerfahrener Untersucher: κ = 0.92 [0.84 – 1] ; p < 0.0001). Die Berechnung der Kappas bezüglich der Einschätzung der Artefaktbildung ergab negative oder nicht definierte Werte ohne Signifikanz. In einer deskriptiven Betrachtung ergab sich eine Tendenz, die CT zu favorisieren. Durchschnittlich beanspruchte die Durchführung eines 3D-Scans 9 Minuten. Eine gänzlich unerfahrene Testperson brauchte für die Erstellung und Analyse von Pedikelschrauben-MPR nach acht Versuchen weniger als eine Minute. Zusammenfassung: Die Bildqualität des Vision RFD 3D reicht aus, um die Pedikelschraubenlage korrekt einzuschätzen. Ein 3D-Scan lässt sich unter moderatem zeitlichen und technischen Aufwand in den OP-Ablauf integrieren. Es fehlt ein Beweis, dass sich die intraoperative 3D-Bildgebung positiv auf die klinisch-funktionellen Langzeitergebnisse der Operationen auswirkt.

The technique of 3D printing offers a high potential for further optimization of spinal surgery. This new technology has been published for different areas in the field of spinal surgery, e.g. in preoperative planning, intraoperative use as well as to create patient-specific implants. For example, it has been demonstrated that preoperative 3‑dimensional visualization of spinal deformities is helpful in planning procedures. Moreover, insertion of pedicle screws seems to be more accurate when using individualized templates to guide the drill compared to freehand techniques. This review summarizes the current literature dealing with 3D printing in spinal surgery with special consideration of the current applications, the limitations and the future potential.Die Technik des 3D-Drucks bietet viel Potenzial in der Wirbelsäulenchirurgie. Diese neue Technologie fand bereits in unterschiedlichen Bereichen der spinalen Chirurgie Anwendung; hierzu zählen die präoperative Planung sowie die intraoperative Insertion und Herstellung von patientenspezifischen Implantaten. Zum Beispiel konnte gezeigt werden, dass die präoperative dreidimensionale Visualisierung spinaler Deformitäten in der Operationsplanung hilfreich ist und die Platzierung von Pedikelschrauben durch individuelle Templates präziser ist als in der Freihandtechnik. Das vorliegende Review fasst die aktuelle Literatur über den 3D-Druck in der Wirbelsäulenchirurgie systematisch unter Berücksichtigung des aktuellen Stands der Anwendungen, der Limitierungen und des Potenzials zusammen.

The goal of surgery for spinal injuries is fracture reduction, fixation and stable healing in a physiological position. Several open and minimally invasive surgical techniques are available.The extent of open reduction and the fixation potential achieved by the AOSpine (AT) and Kluger (KT) techniques were compared. The influence of fracture morphology, age, sex, and bone quality on fracture reduction and secure fixation was investigated.In this monocentric retrospective cohort study data of patients with traumatic thoracolumbar and lumbar fractures treated by AT or KT were analyzed. The bisegmental kyphotic angle (bGDW) of each injured spinal segment was determined. Normal bGDW values were extrapolated from the literature. The change of bGDW over time was analyzed under consideration of the bone quality in Hounsfield units (HU), injury severity according to the AOSpine classification, gender and age of patients.A total of 151 data sets were evaluated. The AT and KT methods achieved a similar extent of reduction (AT 10 ± 6°, KT 11 ± 8°; p = 0.786). In follow-up a mean reduction loss of -5 ± 4° was seen. The technique had no influence on this (p = 0.998). The fracture morphology just managed to achieve a significant influence (p = 0.043). Low HU correlated significantly but weakly with lower extent of reduction (r = 0.241, p 0.003) and greater reduction loss (r = 0.272, p 0.001). In the age group 50-65 years 21% of men and 43% of women had bone quality of 110 HU. Age and HU were significantly correlated (r = -0.701, p 0.001).The AT and KT are equivalent in terms of reduction and secure fixation properties. The high proportion of male and female patients with HU 110 in the age group under 65 years and the influence on reduction and secure fixation emphasize the need for preoperative bone densitometry.HINTERGRUND: Ziel der Operation von Wirbelsäulenverletzungen ist eine stabile Ausheilung in physiologischer Stellung. Für offene und perkutane Operationen stehen unterschiedliche Techniken zur Verfügung.Das Ausmaß der offenen Reposition und das Retentionspotenzial der Techniken nach AOSpine (AT) und nach Kluger (KT) sollen verglichen werden. Der Einfluss von Frakturmorphologie, Alter, Geschlecht und Knochenqualität auf Reposition und Retention werden untersucht.In dieser monozentrischen retrospektiven Kohortenstudie wurden Daten von Patienten mit traumatischen thorakolumbalen und lumbalen Frakturen untersucht, welche entweder mit AT oder KT reponiert wurden. Mittels bisegmentalen Grund-Deckplatten-Winkels (bGDW) wurde die Stellung des verletzten Wirbelsäulenabschnitts beschrieben. Normalwerte für die bGDW wurden anhand von Literaturdaten angenommen. Die Veränderung des bGDW im zeitlichen Verlauf wurde unter Einbeziehung der Knochenqualität in Hounsfield Units (HU), der Verletzungsschwere nach AOSpine und des Patientenalters und -geschlechts analysiert.Es wurden 151 Datensätze ausgewertet. Beide Methoden reponieren vom Umfang nicht unterschiedlich (AT 10 ± 6°, KT 11 ± 8°; p = 0,786). Im Follow-up trat ein Korrekturverlust von −5 ± 4° auf. Die Technik (p = 0,998) hatte keinen Einfluss darauf. Die Frakturmorphologie zeigte einen knapp signifikanten Einfluss (p = 0,043). Niedrige HU korrelierten mit geringerem Repositionsumfang (r = 0,241, p 0,003) und größerem Korrekturverlust (r = 0,272, p 0,001) signifikant, aber schwach. In der Altersgruppe 50 bis 65 Jahre wiesen 21 % der Männer und 43 % der Frauen eine Knochenqualität von HU 110 auf. Alter und HU korrelieren signifikant (r = −0,701, p 0,001).Die Techniken sind gleichwertig bezüglich der Repositions- und Retentionseigenschaften. Der hohe Anteil von Patienten mit HU 110 in der Gruppe unter 65 Jahren bei Frauen und Männern und der Einfluss auf Reposition und Retention weisen auf die Notwendigkeit einer präoperativen Knochendichtemessung hin.

Minimally invasive stabilization of thoracolumbar osteoporotic fractures (OF) in neurologically intact patients is well established. Various posterior and anterior surgical techniques are available. The OF classification and OF score are helpful for defining the indications and choice of operative technique.This article gives an overview of the minimally invasive stabilization techniques, typical complications and outcome.Selective literature search and description of surgical techniques and outcome.Vertebral body augmentation alone can be indicated in painful but stable fractures of types OF 1 and OF 2 and to some extent for type OF 3. Kyphoplasty has proven to be an effective and safe procedure with a favorable clinical outcome. Unstable fractures and kyphotic deformities (types OF 3-5) should be percutaneously stabilized from posterior. The length of the pedicle screw construct depends on the extent of instability and deformity. Bone cement augmentation of the pedicle screws is indicated in severe osteoporosis but increases the complication rate. Restoration of stability of the anterior column can be achieved through additional vertebral body augmentation or rarely by anterior stabilization. Clinical and radiological short and mid-term results of the stabilization techniques are promising; however, the more invasive the surgery, the more complications occur.Minimally invasive stabilization techniques are safe and effective. The specific indications for the individual procedures are guided by the OF classification and the individual clinical situation of the patient.

In the operative treatment of idiopathic scoliosis, posterior correction and fusion in freehand technique is a proven procedure and is frequently performed. Malpositioned pedicle screws can result in serious neurovascular complications. Intraoperative fluoroscopy and neurophysiological measurements are performed to ensure the correct position of pedicle screws. Newer procedures with fluoroscopic- and computertomographic-assisted navigation are advertised as less dangerous and with a more accurate screw position.Is the freehand technique used in the surgical treatment of idiopathic scoliosis safer than other methods with regard to complications caused by screw malposition and intraoperative radiation exposure?Register data of 34 consecutive idiopathic scoliosis patients with two structural curves (Lenke 3 and 6) were collected prospectively in our scoliosis center and were retrospectively analyzed. The following parameters were evaluated: total radiation product, time of fluoroscopy, number of fused segments, time of operation, blood loss, screw-related complications and number of instrumented pedicle screws. All values were given as mean ± standard deviation and statistically analyzed. Finally, our data were compared on accuracy of screw placement and radiation exposure to data from literature with screw placement under navigation.Average age at the time of surgery was 23.6 ± 12 years. The average thoracic curve was 69.2 ± 14.2° preoperatively and 21.7 ± 12.8° postoperatively (correction 69.9%), the average lumbar curve was 64.3° ± 10.8° preoperatively and corrected to 15.6 ± 10.4° postoperatively (correction 76.2%). The total radiation product per patient was 145.7 ± 86.1 cGy*cm², the time of fluoroscopy 31.7 ± 23.5 s (11.5 segments), the time of operation 267.2 ± 64.1 min and the blood loss 700.4 ± 522.3 ml. A total of 803 pedicle screws were placed. No screw-associated complications were detected in the entire collective. The comparison of our data with freehand placement of pedicle screws to literature data showed a noticeable higher radiation exposure for the patient during fluoroscopic- and computertomographic-assisted navigation.The results showed that positioning of pedicle screws with freehand technique in patients with idiopathic scoliosis is accompanied with considerably lower intraoperative radiation exposure compared to fluoroscopic- or computertomographic-assisted navigation. An increased radiation exposure of these typically young patients is associated with an increased long-term risk for the occurrence of radiation-induced malignant diseases. With appropriate surgical experience, placement of pedicle screws in freehand technique is safe and effective and with similar accuracy than screws placed under navigation, but produces significantly less radiation exposure to the patients.In der operativen Therapie der idiopathischen Skoliose hat sich die dorsale Korrekturspondylodese mit Pedikelschrauben-Doppelstabsystem in Freihandtechnik bewährt und wird häufig durchgeführt. Durch Fehllage der Pedikelschrauben können schwerwiegende neurovaskuläre Komplikationen resultieren. Zur Überprüfung einer korrekten Schraubenlage werden intraoperative fluoroskopische Kontrollen sowie neurophysiologische Messungen durchgeführt. Neuere Verfahren mit fluoroskopischer oder computertomografisch gestützter Navigation werden als risikoärmer und mit genauerer Schraubenlage beworben.Ist die Freihandtechnik in der operativen Behandlung der idiopathischen Skoliose in Bezug auf die Komplikationen durch Schraubenfehllage und die intraoperative Strahlenexposition im Vergleich zu anderen Verfahren sicher?Prospektiv wurden Registerdaten von 34 konsekutiven Patienten erfasst und retrospektiv analysiert, die aufgrund einer doppelbogigen idiopathischen Skoliose (Lenke 3 und 6) in unserem Skoliosezentrum operiert wurden. Folgende Parameter wurden ausgewertet: Gesamtstrahlenprodukt, Durchleuchtungszeit, Anzahl fusionierter Segmente, Operationszeit, Blutverlust, schraubenassoziierte Komplikationen und Anzahl der gesetzten Pedikelschrauben. Alle Werte wurden als Mittelwert ± Standardabweichung angegeben und statistisch ausgewertet. Es erfolgte ein Vergleich unserer Daten zur Genauigkeit der Pedikelschraubenlage und der Strahlenbelastung mit den Daten der Literatur bei navigierten Verfahren.Das Alter zum Operationszeitpunkt betrug 23,6 ± 12 Jahre. Die durchschnittliche thorakale Krümmung betrug präoperativ 69,2 ± 14,2° und postoperativ 21,7 ± 12,8° (Korrektur 69,9%), die durchschnittliche lumbale Krümmung präoperativ 64,3 ± 10,8° und postoperativ 15,6 ± 10,4° nach Cobb (Korrektur 76,2%). Das Gesamtstrahlenprodukt pro Patient betrug 145,7 ± 86,1 cGy*cm², die Durchleuchtungszeit 31,7 ± 23,5 s (11,5 Segmente), die Operationszeit 267,2 ± 64,1 min und der Blutverlust 700,4 ± 522,3 ml. Insgesamt wurden 803 Pedikelschrauben gesetzt. Es traten im gesamten Kollektiv keine schraubenassoziierten Komplikationen auf. Der Vergleich unserer Daten in Freihandtechnik mit Literaturdaten zeigte eine für den Patienten deutlich höhere Strahlenexposition bei der fluoroskopisch gestützten und computertomografisch gestützten Technik.Anhand der Ergebnisse konnte gezeigt werden, dass die dorsale Instrumentation mit Pedikelschrauben-Doppelstabsystem in Freihandtechnik bei Patienten mit adoleszenter und adulter idiopathischer Skoliose mit einer erheblich geringeren intraoperativen Strahlenbelastung im Vergleich zu navigierten Verfahren einhergeht. Dabei ist die Art des navigierten Verfahrens unerheblich. Eine erhöhte Strahlenexposition der meist jungen Patienten ist verbunden mit einem erhöhten langfristigen Risiko für das Auftreten strahleninduzierter maligner Erkrankungen. Bei entsprechender chirurgischer Erfahrung können Pedikelschrauben in Freihandtechnik mit vergleichbarer Genauigkeit sicher und effektiv gesetzt werden, führen jedoch zu einer signifikant geringeren Strahlenbelastung für den Patienten.

A proven and frequently used surgical procedure in patients with idiopathic scoliosis (IS) is posterior transpedicular corrective spondylodesis using the freehand technique. Novel procedures with fluoroscopically and computed tomography (CT)-assisted navigation are presumed to be less risky and more accurate.Is the freehand technique for IS safe with respect to screw-associated complications and intraoperative radiation exposure?Prospectively collected data (2017-2018) from 39 consecutive patients (average age 18.7 years) with thoracic single curvature IS (61.7° ± 13.9°) from a specialized scoliosis center were evaluated for the following parameters (mean ± standard deviation): total radiation product, fluoroscopy time, fused segments, operative time, blood loss and screw-associated complications. A comparison with data from the literature on intraoperative radiation exposure using navigation procedures was carried out.The total radiation product per patient was 71.7 ± 44.0 cGy*cmThe results of this study showed that with appropriate experience freehand positioning of pedicle screws is associated with comparable accuracy and less radiation exposure for patients than navigation procedures. With respect to the young age of patients, a radiation-induced long-term risk for malignant diseases should be taken into consideration.

Safe placement of posterior cervical or high-thoracic pedicle screws, transarticular screws C1/2, translaminar screws C2 or cervical lateral mass screws under the guidance of spinal navigation.All posterior cervical and cervicothoracic instrumentation with screws: instabilities and deformities of rheumatoid, traumatic, neoplastic, infectious, iatrogenic or congenital origin; multilevel cervical spinal stenosis with degenerative instability or kyphosis of the affected spinal segment.There are no absolute contraindications.Prone position on a gel mattress, rigid head fixation, e.g., with Mayfield tongs; if appropriate, closed reduction under lateral image intensification; midline posterior surgical approach at the level of the segments to be instrumented; if necessary, open reduction; insertion of the cervical/upper thoracic screws under the guidance of spinal navigation; if necessary, posterior decompression; instrumentation longitudinal rods; if a fusion is to be obtained, decortication of the posterior bone elements with a high-speed burr and onlay of cancellous bone or bone substitutes.In stable instrumentation, no postoperative immobilization with cervical collar is necessary. Drain removal on postoperative day 2-3, suture removal on postoperative day 14, clinical and x‑ray control 3 and 12 months after surgery or in case of clinical or neurological deterioration.Numerous studies showed that the use of spinal navigation reduces implant malplacement rates significantly. Furthermore, it allows a reduction of the radiation dose for the operation team up to 90%.

Spinal navigation has evolved greatly since its implementation in the mid-1990s and is now widely used in lumbar spine surgery. However, navigation is not yet accepted as a standard technique.In addition to the classic use in lumbar pedicle screw instrumentation, navigation technology, especially in combination with intraoperative 3D imaging, can be applied in a wide range of indications and in all lumbar approaches. The technology is particularly helpful in minimally invasive operations. The concept of "total navigation" stands for an efficient use of the technique from skin incision on and aims at complete elimination of radiation exposure for the surgical team.High accuracy and low radiation exposure of the OR team are indisputable advantages of navigated operations, while time savings and economic benefits are yet to be demonstrated. Regular use and standardized workflow are essential for the safe and effective application of lumbar navigation. Currently, lumbar navigation technology is already of great importance, yet the complex technology requires intensive training. With improved user comfort and image quality, spinal navigation will continue to spread in the future.

Intraoperative revision of initially loosened pedicle screws.Intraoperatively loosened/stripped pedicle screws.None.Removal of the loosened/stripped pedicle screw. Checking the screw channel and re-implantation using a different trajectory, a larger screw diameter or a cement-augmented pedicle screw.Early functional mobilization and initiation of osteoporosis therapy if indicated.A biomechanical study with human vertebral bodies was performed. Augmented and not augmented pedicle screws were tested until loosening using a fatigue testing setup. After loosening occurred a subsequent augmentation of the loosened, not augmented screw was performed, and it was tested using a fatigue test again. Both the initial (p = 0.009) and the augmentation after loosening (p = 0.001) showed a significant increase in failure load compared to the non-augmented pedicle screws. In our own patient collective from April 2016 to August 2018, 11 of 524 patients treated with pedicle screws showed intraoperative screw loosening. This was revised in 6 cases with a subsequent augmentation and in 5 cases with a larger screw diameter. In the postoperative control at 6 weeks, none of these screws showed loosening again.

Operative stabilisation of osteoporotic vertebral fractures.Fractures of the thoracic and lumbar spine.None.Preoperative determination of expected bone mineral density. Implantation of pedicle screws in special trajectories, cement augmentation of the screws and use of alternative implants.Early functional mobilisation and initiation of osteoporosis therapy if indicated.A biomechanical cadaver study with human vertebral bodies was performed. There was a highly significant correlation between bone mineral density and the fatigue load (r

Stabilization of the atlantoaxial transition by an alternative screw position in C1.Instabilities C1/C2 due to inflammation, tumor or trauma.Presence of a very small pedicle of C1. Variations in the course of the vertebral arteries.The midline approach to the upper cervical spine is used for the modified instrumentation of C1 with pedicle screws instead of Harms screws and for the unaltered instrumentation of C2. Depending on the indication, dorsal spondylodesis is performed by opening the laminae and attaching ceramic bone substitute material.In mobile patients, additional immobilisation with a soft collar is recommended for 6 weeks. Full recovery is given 3-4 months after surgery.From January 2017 to September 2018, 21 stabilizations of the atlantoaxial transition were performed. The mean age was 72.52 ± 15.45 years. A total of 42 screws were placed in C1. In all, 21 (50%) C1 pedicle screwscould be placed, and in other 21 cases Harms screws were used. Complications were seen in 3 patients. Overall, considering the contraindications, the instrumentation of C1 with pedicle screws appears as a safe alternative to instrumentation with Harms screws.

Spinal navigation has made significant advances in the last two decades. After initial experiences with pedicle screws in the thoracic and lumbar spine, technological improvements have resulted in their increased application in the cervical spine. Instrumentation techniques like cervical pedicle screws, lateral mass screws in C1 and transarticular screws C1/C2 have become standard due to the application of image guidance.Different navigation techniques can be distinguished based on the type of imaging. In the cervical spine, the preoperative computer tomography (CT) scan that requires intraoperative matching is still the standard of care due to the high image quality. 3D fluoroscopy navigation techniques are currently widely used in the lumbar spine, but the reduced image quality obviates the application in the more sophisticated cervical anatomy or the cervicothoracic region. The future availability of intraoperative CT scans (iCT) combines the advantages of high image quality with those of intraoperative image acquisition. This will lead to a wider use of image guidance in the cervical spine and will enable the surgeon to apply minimally invasive techniques with higher accuracy.The successful application of spinal navigation is based on the technical knowledge of navigation systems and its exercise in daily routine. Only the sufficient experience of the clinical staff makes it possible to standardize operational procedures to increase patient safety, reduce radiation dose and shorten operation time.

Cement-augmented pedicle screws can increase the stability of fixators for unstable vertebral fractures in the elderly. Fixators can be inserted quickly and with minimally invasive techniques, reducing surgical risks. From March 2012 until July 2014, we treated 40 patients with percutaneous augmented fixators for unstable vertebral fractures. Average age was 77.5 years. During the six month observation period, no patients died. There were no neurological deficits. On VAS, average pain decreased from 8.5 to 4.1 points postoperatively. The average Cobb angle of 4.1° was improved after surgery. After 6 months, bony consolidation yielded angles of 1 to 4°, average 2.6°. There was often venous extravasation of cement leaking from the augmented vertebrae, even extending to pulmonary embolism. The emboli were usually asymptomatic. We report a case where the patient required resuscitation immediately after cement application because of pulmonary emboli. The patient survived because of the immediately implemented critical care measures. Little has been published about this risk, which is underestimated despite increasing numbers of augmented fixator operations. The risk can be reduced with slower cement injection, smaller cement applicators, and short term positive pressure ventilation with PEEP.Mit zementaugmentierten Pedikelschrauben kann die Festigkeit von Fixateuren bei instabilen Wirbelfrakturen im Alter erhöht werden. Die Fixateure können minimalinvasiv und schnell eingebracht werden und verringern das Operationsrisiko. Wir haben von März 2012 bis Juli 2014 40 Patienten mit instabilen Wirbelfrakturen mit einem perkutanen augmentierten Fixateur versorgt. Das Durchschnittsalter betrug 77,5 Jahre. Kein Patient verstarb im Beobachtungszeitraum von 6 Monaten. Neurologische Ausfälle traten nicht auf. Die Schmerzen konnten von im Mittel 8,5 Punkten auf der VAS auf 4,1 Punkte postoperativ gesenkt werden. Durch die Operation konnte der Cobb-Winkel im Mittel um 4,1° verbessert werden. Nach 6 Monaten kam es nur zu einer Sinterung von 1° bis max. 4°, im Mittel 2,6°. Häufig kam es aber zu venösen Paravasaten durch Zementabflüsse aus den augmentierten Wirbeln bis hin zur Lungenembolie. Meist bleiben diese Embolien asymptomatisch. Wir berichten über einen Patienten, der unmittelbar nach der Zementapplikation aufgrund von Lungenembolien reanimationspflichtig wurde. Der Patient überlebte aufgrund der sofort durchgeführten intensivmedizinischen Maßnahmen. Das Risiko ist in der Literatur wenig bekannt und bislang unterschätzt trotz steigender Operationszahlen mit augmentierten Fixateuren. Eine Reduzierung des Risikos ist durch langsame Zementinjektion, kleinere Zementapplikatoren und kurzfristiger Überdruckbeatmung mit PEEP (positive expiratory pressure) möglich.

To reduce the rate of implant failures at the lumbosacral junction in polysegmental lumbar fusions.Spinal fusion with deformity correction including L5/S1, revision surgery for pseudoarthrosis L5/S1, screw pull-out and pedicle fractures in S1, and S1/S2 fractures after polysegmental fusions.Osteosynthesis of complex pelvic ring fractures, tumors of the ilium. Relative contraindication: infection, to avoid contamination of the iliosacral joint.Conventional posterior approach to the lumbar spine. Positioning of the lumbar and S1 pedicle screws in common technique. Identification of the correct entrance point for one or two S2-Ala-iliac screws for each side and preparation of the drill holes in freehand technique. Connection of the lumbar and S1 pedicle screws and S2-Ala-iliac screws with one stress-free rod on each side without the use of connectors or special plates.Back-friendly mobilization beginning on day 1 after surgery with support of a physiotherapist. No sports for 12 weeks.In all, 25 patients were treated with an extended pelvic fixation using S2-Ala-iliac screws. A primary deformity correction was performed in 11 patients, whereas 14 patients underwent revision surgery. A total of 24 patients were clinically and radiologically followed for a mean of 16 months. Two patients showed a loosening of the S2-Ala-iliac screws on one side, and one patient had broken screw as well only on one side without clinical symptoms. So far, no patient has undergone revision surgery because of S2-Ala-iliac screw-associated complications.

Cement augmentation of pedicle screws biomechanically increases screw purchase in the bone. However, clinical complications may occur. The pros and cons of the technique are discussed from different clinical perspectives.

Transpedicular screw fixation of spinal segments has been described for a variety of surgical indications and is a key element in spinal surgery. The aim of transpedicular screw fixation is to achieve maximal stability. Screw malposition should be obviated to avoid neurological complications. There are published methods of applying evoked EMG to control screw position in relation to neural structures. These studies demonstrated that an intact bony pedicle wall acts as an electrical isolator between the screw and spinal nerve root. The aim of our study was to evaluate the impact of intraoperative pedicle screw monitoring on screw positioning.We enrolled 22 patients in this prospective randomised study, who underwent spinal instrumentation after being split into two equal groups. In the first group, dorsal instrumentation was supplemented with intraoperative nerve root monitoring using the INS-1-System (NuVasive, San Diego USA). In the second group, screws were inserted without additional pedicle monitoring. All patients underwent monosegmental instrumentation with "free hand implanted" pedicle screws. 44 screws were inserted in each group. The screw position was evaluated postoperatively using CT scans. The position of the screws in relation to the pedicle was measured in three different planes: sagittal, axial and coronal. The accuracy of the screw position was described using the Berlemann classification system. Screw position is classified in three groups: type 1 correct screw position, type 2 encroachment on the inner cortical wall, type 3 pedicle cortical perforation. Screw angulation and secondary operative criteria were also evaluated.The use of neuromonitoring did not influence the distance between the centre of the screws and the pedicle wall. Distances only depended on the implantation side (right and left) and the height of implantation (caudal or cranial screw). Because of the low number of cases, no conclusion could be reached about the influence of root monitoring on the correct positioning of the screws. There was at least a non-significant trend towards more frequent perforation of the pedicle in the monitor group. In the present study, we showed that root monitoring had a significant effect on the scattering of transversal angles. These were increased compared to the control group. Otherwise, the implantation angle was not shown to depend on the use of neuromonitoring. Neuromonitoring did not influence blood loss or operative time.The data did not permit any conclusion as to whether this technique can minimise the frequency of pedicle screw malposition. The four coronal plane distances did not depend on the use of neuromonitoring. The inclination angle was also unaffected by neuromonitoring. The only parameter for which we found any effect was the transverse angle. The mean values were similar in both groups, but the variances were not equal. The effect of monitoring on the only parameter which could not be evaluated by fluoroscopy is thus rather unfavourable.

Objective: Pedicle screws are used for stabilization of vertebral fractures. Inaccurate positioning of the screws can result in severe complications such as permanent neurological damage. Literature suggests an increased screw placement accuracy when computer assisted navigation systems are used. However, especially in the thoracic spine there is yet no clear proof for the superiority of navigated procedures versus the conventional approach. The objective of this study was to assess the placement accuracy and potential influencing factors of 3D-navigated versus conventionally inserted pedicle screws. Methods: A retrospective analysis of a prospective database at a level 1 trauma center of pedicle screw placement (3D-navigated versus conventionally placed) was carried out for dorsal spinal stabilization. Placement accuracy was assessed in three grades based on post-operative computed tomography. In addition, influencing factors such as body mass index, spinal level and experience level of the surgeon were analyzed, using a multivariate regression model. Results: The overall placement accuracy was 86 % in the conventional group vs. 79 % in the navigated group (perfect placement, grade 0). The navigated procedures were superior in the lumbar spine and the conventional ones were superior in the thoracic spine, though there was no statistically significant difference. The surgeon’s experience level and the patient’s body mass index did not influence the placement accuracy. The only significant factor of influence was the spinal segment: The higher the spinal level of screw placement, the lower the achieved placement accuracy. Conclusions: 3D-navigated and conventional methods are both safe procedures to place pedicle screws at the traumatized spine. At the moment, 3D-navigation does not significantly increase screw placement accuracy. Accuracy is lowest in the high thoracic spine level with both methods.

The number of spinal operations carried out per year is steadily increasing. Pedicle screw placement is the standard procedure for spinal stabilization but can be associated with severe complications. Intraoperative navigation can increase the accuracy of placement of the screws and a decisive role is played by the improvement in imaging devices. Nowadays, 3D-navigation is performed using intraoperative computed tomography or a flatpanel-3D C-arm. Computer navigation is a crucial aid especially for complex deformities or tumor cases. However, as yet no statistically significant reduction of complications could be shown using navigation compared to conventional procedures. With continuing development of intraoperative imaging and navigation it is hoped that screw positioning can be improved further.

Minimally invasive surgery for vertebral fractures results in less approach-related morbidity, decreased postoperative pain, and rapid mobilisation of patients. Such procedures can be performed even in elderly patients. However, along with the many advantages, minimally invasive procedures are technically demanding, require sophisticated tools, and there is a learning curve for surgeons. Intraoperative visualisation is often possible only radiologically, and implants are generally much more expensive. Using the data from over 300 unstable vertebral fracture cases treated over the past 3.5 years, we have developed a differentiated treatment concept, depending on the age of the patient and the fracture characteristics. Unstable fractures with involvement of the posterior edge are stabilised from posterior, percutaneously with a fixator. In patients under 60 years, monoaxial screws with inserted rods (top loading) are used, with which distraction and restoration of lordosis are also possible. Patients over 60 years are treated percutaneously with a polyaxial sextant system with rods inserted to avoid avulsion of the pedicle screws from the vertebral body. To avoid cutting through the vertebra, the fenestrated screws can be augmented with cement. The operation technique is demonstrated by a video.