C. Fleege

Small cavity creation in the vertebral body reduces the rate of cement leakage during vertebroplasty

Cement leakage is the most common complication during vertebroplasty and may result in serious morbidity. Measures to reduce the rate of cement leakage are valuable ways to improve vertebroplasty safety. The present study aimed to evaluate whether creating a small cavity in the vertebral body prior to cement injection would reduce the rate of cement leakage during vertebroplasty. The study included 36 consecutive patients with 42 painful osteoporotic vertebral body compression fractures that were classified as A1 fractures according to AO classification. Patients were randomly assigned to receive either treatment with vertebroplasty (control) or with a procedure termed cavuplasty, in which a small cavity was created in the vertebral body prior to cement injection. CT scanning was performed to detect cement leakage. Cement leakage was observed in 14 (66.6%) of the 21 vertebral bodies treated with vertebroplasty and 5 (23.8%) of the 21 vertebral bodies treated with cavuplasty (p = 0.012). These results suggest that the creation of a small cavity in the vertebral body prior to cement injection is an effective way to reduce cement leakage during vertebroplasty.

Interkorporelle Fusionsverfahren an der Wirbelsäule

ZusammenfassungHintergrundDie Entwicklung der interkorporellen Fusionsverfahren erstreckt sich mittlerweile über viele Jahrzehnte und ist noch immer nicht abgeschlossen.DiskussionAufgrund der Abwesenheit von entsprechenden Implantaten erfolgten die initialen Fusionen durch Dekortizierung der dorsalen und lateralen Strukturen der Wirbelsäule und anschließendes Anlagern von autologem Knochenmaterial. Trotz passabler Fusionsergebnisse manifestierte sich das Bestreben nach einer besseren Primärstabilität und höheren Fusionsraten. Zudem verbreitete sich auch das Verständnis, dass der primär lasttragende Anteil der Wirbelsäule ventral im Bereich des Corpus der Wirbelkörper liegt. Diese Überlegungen führten letztendlich zur Entwicklung der PLIF-Technik (posteriore lumbale interkorporelle Fusion), die unter Cloward 1953 deutlich an Popularität gewann. Nach Ausräumung des Bandscheibenfaches interpositionierte er Beckenkammknochenblöcke zwischen die Wirbelkörper, die sich entsprechend verklemmten. Basierend auf dieser Technik und diesen Überlegungen erfolgte in den 1970er Jahren die Entwicklung von intervertebralen Implantaten. Der sog. „Bagby Basket“ war der erste intervertebrale Cage, der zunächst bei Pferden mit „Wobbler-Syndrom“ eingesetzt wurde. Weitere Meilensteine in der Verbesserung des Cagedesigns schlossen sich an, was zur Herstellung vielzähliger Implantatformen und -materialien führte. Das Elastizitätsmodul der intersomatischen Implantate näherte sich durch moderne Werkstoffe immer mehr dem von Knochen an, so dass ein Einsintern der Cages reduziert und die Fusionen weiter gesteigert werden konnten. Durch den Einsatz von Schrauben-Stab-Systemen konnte die Primärstabilität zusätzlich weiter gesteigert werden, sodass die dorsale Instrumentierung heute den Standard im Rahmen von PLIF (posteriore lumbale interkorporelle Fusion)- und TLIF-Prozeduren (transforaminale lumbale interkorporelle Fusion) darstellt. Das von Harms beschriebene TLIF-Verfahren war eine neue Modifikation und konnte Komplikationen bei lumbalen Fusionen minimieren sowie die Invasivität des Eingriffs reduzieren.SchlussfolgerungHeutzutage steht uns eine Vielzahl unterschiedlichster Implantate und Implantationstechniken zur Verfügung, was die interkorporelle Fusion in PLIF- und TLIF-Technik zu sicheren und erfolgreichen Verfahren macht.AbstractBackgroundThe development of interbody fusion now stretches over many decades and is still not complete.DiscussionDue to the lack of appropriate implants, the initial fusions were performed via decortication of the dorsal and lateral structures of the spine, followed by placement of an autograft. Despite acceptable fusion results, better primary stability and higher fusion rates were desired. In addition, it became known that the primary load-bearing of the spine is located ventrally in the area of the corpus of the vertebrae. These considerations led to the development of the PLIF technique that was introduced by Cloward in 1953 and gained significantly in popularity. After removal of the intervertebral disc, he positioned iliac crest bone blocks between the vertebral bodies. Based on this technique and these considerations, intervertebral implants were developed in the 1970s. The so-called Bagby Basket was the first intervertebral cage that was initially used in horses with wobbler syndrome. Other milestones in the improvement of the cage designs followed, resulting in the production of different implant shapes and materials. The elastic modulus of the interbody implants approached by modern materials became more and more similar to bone, so that subsidence of cages reduced and the fusion rate could be further increased. The primary stability could be further increased with screw–rod systems, so that dorsal instrumentation became the standard in the context of PLIF and TLIF procedures today. The TLIF procedure described by Harms was a new modification and minimized complications of lumbar fusions and reduced the invasiveness of the procedure.ConclusionNowadays a wide variety of implants and implantation techniques are available, making interbody fusions in PLIF and TLIF techniques safe and successful procedures.BACKGROUND The development of interbody fusion now stretches over many decades and is still not complete. DISCUSSION Due to the lack of appropriate implants, the initial fusions were performed via decortication of the dorsal and lateral structures of the spine, followed by placement of an autograft. Despite acceptable fusion results, better primary stability and higher fusion rates were desired. In addition, it became known that the primary load-bearing of the spine is located ventrally in the area of the corpus of the vertebrae. These considerations led to the development of the PLIF technique that was introduced by Cloward in 1953 and gained significantly in popularity. After removal of the intervertebral disc, he positioned iliac crest bone blocks between the vertebral bodies. Based on this technique and these considerations, intervertebral implants were developed in the 1970s. The so-called Bagby Basket was the first intervertebral cage that was initially used in horses with wobbler syndrome. Other milestones in the improvement of the cage designs followed, resulting in the production of different implant shapes and materials. The elastic modulus of the interbody implants approached by modern materials became more and more similar to bone, so that subsidence of cages reduced and the fusion rate could be further increased. The primary stability could be further increased with screw-rod systems, so that dorsal instrumentation became the standard in the context of PLIF and TLIF procedures today. The TLIF procedure described by Harms was a new modification and minimized complications of lumbar fusions and reduced the invasiveness of the procedure. CONCLUSION Nowadays a wide variety of implants and implantation techniques are available, making interbody fusions in PLIF and TLIF techniques safe and successful procedures.

Erratum zu: Prä- und postoperative Fast-track-Behandlungskonzepte in der Wirbelsäulenchirurgie. Patienteninformation und Patientenkooperation

BACKGROUND: Evidence-based procedures and pathways to reduce peri- and postoperative complications, while simultaneously achieving a high satisfaction rate of patients and lower costs are important goals in the treatment of orthopedic patients. PURPOSE: This article describes the key factors to improve treatment of patients with indications for stabilization of one or two segments in the field of degenerative lumbar spine pathologies. A fast-track concept was developed to optimize the pathway of treatment, while increasing patient satisfaction and shortening the hospital stay. In the present patient cohort, significantly greater patient satisfaction and significantly shorter hospital stays were achieved. RESULTS: The hospital stay was reduced from 10.9 to 6.2 days after introduction of a multimodal patient school that was held 10 days prior to admission, with mobilization on the day of surgery with a strictly followed treatment plan supervised by therapists and taking into account the patients own assessment, as well an early plan for discharge based on fixed established criteria. This concept is a very successful tool to achieve high quality standard of treatment paired with a reduction of hospital stay.

Anterior cement augmentation of adjacent levels after vertebral body replacement leads to superior stability of the corpectomy cage under cyclic loading – a biomechanical investigation

BACKGROUND In the operative treatment of osteoporotic vertebral body fractures, a dorsal stabilization in combination with a corpectomy of the fractured vertebral body might be necessary with respect to the fracture morphology, whereby the osteoporotic bone quality may possibly increase the risk of implant failure. To achieve better stability, it is recommended to use cement-augmented screws for dorsal instrumentation. Besides careful end plate preparation, cement augmentation of the adjacent end plates has also been reported to lead to less reduction loss. PURPOSE The aim of the study was to evaluate biomechanically under cyclic loading whether an additional cement augmentation of the adjacent end plates leads to improved stability of the inserted cage. STUDY DESIGN/SETTING Methodical cadaver study. MATERIALS AND METHODS Fourteen fresh frozen human thoracic spines with proven osteoporosis were used (T2-T7). After removal of the soft tissues, the spine was embedded in Technovit (Kulzer, Germany). Subsequently, a corpectomy of T5 was performed, leaving the dorsal ligamentary structures intact. After randomization with respect to bone quality, two groups were generated: Dorsal instrumentation (cemented pedicle screws, Medtronic, Minneapolis, MN, USA)+cage implantation (CAPRI Corpectomy Cage, K2M, Leesburg, VA, USA) without additional cementation of the adjacent endplates (Group A) and dorsal instrumentation+cage implantation with additional cement augmentation of the adjacent end plates (Group B). The subsequent axial and cyclic loading was performed at a frequency of 1 Hz, starting at 400 N and increasing the load within 200 N after every 500 cycles up to a maximum of 2,200 N. Load failure was determined when the cages sintered macroscopically into the end plates (implant failure) or when the maximum load was reached. RESULTS One specimen in Group B could not be clamped appropriately into the test bench for axial loading because of a pronounced scoliotic misalignment and had to be excluded. The mean strength for implant failure was 1,000 N±258.2 N in Group A (no cement augmentation of the adjacent end plates, n=7); on average, 1,622.1±637.6 cycles were achieved. In Group B (cement augmentation of the adjacent end plates, n=6), the mean force at the end of loading was 1,766.7 N±320.4 N; an average of 3,572±920.6 cycles was achieved. Three specimens reached a load of 2,000 N. The differences between the two groups were significant (p=.006 and p=.0047) regarding load failure and number of cycles. CONCLUSIONS Additional cement augmentation of the adjacent end plates during implantation of a vertebral body replacement in osteoporotic bone resulted in a significant increased stability of the cage in the axial cyclic loading test.

Umsetzung des Fast-Track-Konzepts in der Wirbelsäulenchirurgie

Europaweit erste Erfahrungen mit Fast-Track-Behandlungskonzepten bei mono- und bisegmentalen lumbalen Spondylodesen konnten zeigen, dass die Etablierung eines evidenzbasierten- und strukturierten Behandlungspfades fur die Wirbelsaulenchirurgie einerseits moglich ist, andererseits bei einer aktuellen Zahl von 302 versorgten Patienten deutliche qualitative Verbesserungen mit Reduktion der Operationsdauer, des intraoperativen Blutverlustes wie auch der Krankenhausverweildauer von 10 auf 6,2 Tage erzielt werden konnen. Eine interdisziplinare Zusammenarbeit mit multifaktoriellen pra-, intra- und postoperativen Optimierungen sowie eine Fokussierung auf eine ausfuhrliche praoperative Information und eine rasche postoperative Mobilisation des Patienten ergeben eine hohe Patientenzufriedenheit und eine qualitativ hochwertige medizinische Versorgung.

Interkorporelle Fusionsverfahren an der Wirbelsäule@@@Interbody fusion procedures: Die Entwicklung aus historischer Sicht@@@Development from a historical perspective

ZusammenfassungHintergrundDie Entwicklung der interkorporellen Fusionsverfahren erstreckt sich mittlerweile über viele Jahrzehnte und ist noch immer nicht abgeschlossen.DiskussionAufgrund der Abwesenheit von entsprechenden Implantaten erfolgten die initialen Fusionen durch Dekortizierung der dorsalen und lateralen Strukturen der Wirbelsäule und anschließendes Anlagern von autologem Knochenmaterial. Trotz passabler Fusionsergebnisse manifestierte sich das Bestreben nach einer besseren Primärstabilität und höheren Fusionsraten. Zudem verbreitete sich auch das Verständnis, dass der primär lasttragende Anteil der Wirbelsäule ventral im Bereich des Corpus der Wirbelkörper liegt. Diese Überlegungen führten letztendlich zur Entwicklung der PLIF-Technik (posteriore lumbale interkorporelle Fusion), die unter Cloward 1953 deutlich an Popularität gewann. Nach Ausräumung des Bandscheibenfaches interpositionierte er Beckenkammknochenblöcke zwischen die Wirbelkörper, die sich entsprechend verklemmten. Basierend auf dieser Technik und diesen Überlegungen erfolgte in den 1970er Jahren die Entwicklung von intervertebralen Implantaten. Der sog. „Bagby Basket“ war der erste intervertebrale Cage, der zunächst bei Pferden mit „Wobbler-Syndrom“ eingesetzt wurde. Weitere Meilensteine in der Verbesserung des Cagedesigns schlossen sich an, was zur Herstellung vielzähliger Implantatformen und -materialien führte. Das Elastizitätsmodul der intersomatischen Implantate näherte sich durch moderne Werkstoffe immer mehr dem von Knochen an, so dass ein Einsintern der Cages reduziert und die Fusionen weiter gesteigert werden konnten. Durch den Einsatz von Schrauben-Stab-Systemen konnte die Primärstabilität zusätzlich weiter gesteigert werden, sodass die dorsale Instrumentierung heute den Standard im Rahmen von PLIF (posteriore lumbale interkorporelle Fusion)- und TLIF-Prozeduren (transforaminale lumbale interkorporelle Fusion) darstellt. Das von Harms beschriebene TLIF-Verfahren war eine neue Modifikation und konnte Komplikationen bei lumbalen Fusionen minimieren sowie die Invasivität des Eingriffs reduzieren.SchlussfolgerungHeutzutage steht uns eine Vielzahl unterschiedlichster Implantate und Implantationstechniken zur Verfügung, was die interkorporelle Fusion in PLIF- und TLIF-Technik zu sicheren und erfolgreichen Verfahren macht.AbstractBackgroundThe development of interbody fusion now stretches over many decades and is still not complete.DiscussionDue to the lack of appropriate implants, the initial fusions were performed via decortication of the dorsal and lateral structures of the spine, followed by placement of an autograft. Despite acceptable fusion results, better primary stability and higher fusion rates were desired. In addition, it became known that the primary load-bearing of the spine is located ventrally in the area of the corpus of the vertebrae. These considerations led to the development of the PLIF technique that was introduced by Cloward in 1953 and gained significantly in popularity. After removal of the intervertebral disc, he positioned iliac crest bone blocks between the vertebral bodies. Based on this technique and these considerations, intervertebral implants were developed in the 1970s. The so-called Bagby Basket was the first intervertebral cage that was initially used in horses with wobbler syndrome. Other milestones in the improvement of the cage designs followed, resulting in the production of different implant shapes and materials. The elastic modulus of the interbody implants approached by modern materials became more and more similar to bone, so that subsidence of cages reduced and the fusion rate could be further increased. The primary stability could be further increased with screw–rod systems, so that dorsal instrumentation became the standard in the context of PLIF and TLIF procedures today. The TLIF procedure described by Harms was a new modification and minimized complications of lumbar fusions and reduced the invasiveness of the procedure.ConclusionNowadays a wide variety of implants and implantation techniques are available, making interbody fusions in PLIF and TLIF techniques safe and successful procedures.BACKGROUND The development of interbody fusion now stretches over many decades and is still not complete. DISCUSSION Due to the lack of appropriate implants, the initial fusions were performed via decortication of the dorsal and lateral structures of the spine, followed by placement of an autograft. Despite acceptable fusion results, better primary stability and higher fusion rates were desired. In addition, it became known that the primary load-bearing of the spine is located ventrally in the area of the corpus of the vertebrae. These considerations led to the development of the PLIF technique that was introduced by Cloward in 1953 and gained significantly in popularity. After removal of the intervertebral disc, he positioned iliac crest bone blocks between the vertebral bodies. Based on this technique and these considerations, intervertebral implants were developed in the 1970s. The so-called Bagby Basket was the first intervertebral cage that was initially used in horses with wobbler syndrome. Other milestones in the improvement of the cage designs followed, resulting in the production of different implant shapes and materials. The elastic modulus of the interbody implants approached by modern materials became more and more similar to bone, so that subsidence of cages reduced and the fusion rate could be further increased. The primary stability could be further increased with screw-rod systems, so that dorsal instrumentation became the standard in the context of PLIF and TLIF procedures today. The TLIF procedure described by Harms was a new modification and minimized complications of lumbar fusions and reduced the invasiveness of the procedure. CONCLUSION Nowadays a wide variety of implants and implantation techniques are available, making interbody fusions in PLIF and TLIF techniques safe and successful procedures.

Posteriore lumbale interkorporelle Fusionscages@@@Posterior lumbar interbody fusion implants: Softwarebasierte Operationsplanung – erste Ergebnisse@@@Software assisted planning – preliminary results

BACKGROUND Sagittal imbalance, adjacent segment degeneration, and loss of correction due to cage sintering are the main reasons for revision surgery after lumbar fusion. Based on the experience from hip and knee replacement surgery, preoperative software-assisted planning combined with the corresponding cages is helpful to achieve better long-term results. OBJECTIVES Evaluation of the procedure regarding intraoperative application of preoperative planning and examination to what extent the planning was correct. MATERIALS AND METHODS In all, 30 patients were included in the period from September 2012 to May 2013 in an observational study, planned preoperatively with the planning software, and treated with the corresponding PLIF cages. The radiological evaluation was performed by thin-layer CT after 3 months. RESULTS A total of 24 (80%) patients were followed up after 3 months. In these 24 patients, the preoperative planning actually was correct in 17 cases with the intraoperatively implanted cage, which corresponds to a match of about 71%. The fusion rate for these 24 patients who underwent full examinations was 91.7%. CONCLUSION The results of this observational study to evaluate the planning of intervertebral cages show positive experience with this novel therapeutic concept. Despite the limited number of participants, good results were observed for the intraoperative implementation of the planned cages and an adequate fusion rate was obtained. Irrespective of this, a software-based surgical planning must be questioned critically any time. Ultimately, it is the surgeons responsibility to modify the planned procedure intraoperatively if necessary. Currently, the influence of this planning regarding the long-term course and the important question of adjacent segment instability remains unanswered.