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AIMS Giant cell tumour of bone (GCTB) is histologically defined as a lesion containing reactive giant cells and a neoplastic mononuclear cell population; in up to 92% of cases, GCTB is characterised by a specific mutation of the histone gene H3F3A. The cellular composition ranges from giant-cell-rich to giant-cell-poor. The diagnosis of GCTB can be challenging, and several other lesions need to be excluded, e.g. aneurysmal bone cysts, non-ossifying fibromas, chondroblastomas, brown tumours, and giant-cell-rich osteosarcomas. Our aim was to analyse the clinical history, imaging, molecular pathology and histology of three H3F3A-mutated bone tumours without detectable giant cells. None of the patients received denosumab therapy. METHODS AND RESULTS Diagnostic material was obtained by curettage or resection and/or biopsy. Common histomorphological features of all three reported lesions were fibrocytic, oval cells in a background of osteoid and an absence of multinuclear giant cells as confirmed with CD68 immunohistochemistry. We used immunohistochemistry and Sanger sequencing to demonstrate positivity for the H3.3 p.G34W mutation. Differential diagnoses were systematically excluded on the basis of histomorphology, immunohistochemistry, and fluorescence in-situ hybridisation. The imaging (radiography, computed tomography, and magnetic resonance imaging) for all three cases is presented and discussed. CONCLUSIONS We believe that these GCTBs without giant cells expand one end of the heterogeneous range of GCTB. Because of the lack of giant cells, correct diagnosis of GCTB is challenging or even impossible on histological grounds alone. In these cases, detection of the characteristic H3F3A mutation (G34W-specific antibody RM263 or sequencing) is extremely helpful for diagnosing those lesions without giant cells as giant cell tumours of bone. more...

Leiomyosarcoma (LMS) is characterized by high genomic complexity, and to date, no specific targeted therapy is available. In a genome-wide approach, we profiled genomic aberrations in a small cohort of eight primary tumours, two relapses, and eight metastases across nine different patients. We identified CDK4 amplification as a recurrent alteration in 5 out of 18 samples (27.8%). It has been previously shown that the LMS cell line SK-LMS-1 has a defect in the p16 pathway and that this cell line can be inhibited by the CDK4 and CDK6 inhibitor palbociclib. For SK-LMS-1 we confirm and for SK-UT-1 we show that both LMS cell lines express CDK4 and that, in addition, strong CDK6 expression is seen in SK-LMS-1, whereas Rb was expressed in SK-LMS-1 but not in SK-UT-1. We confirm that inhibition of SK-LMS-1 with palbociclib led to a strong decrease in protein levels of Phospho-Rb (Ser780), a decreased cell proliferation, and G0/G1-phase arrest with decreased S/G2fractions. SK-UT-1 did not respond to palbociclib inhibition. To compare thesein vitrofindings with patient tissue samples, a p16, CDK4, CDK6, and p-Rb immunohistochemical staining assay of a large LMS cohort (n=99patients with 159 samples) was performed assigning a potential responder phenotype to each patient, which we identified in 29 out of 99 (29.3%) patients. Taken together, these data show that CDK4/6 inhibitors may offer a new option for targeted therapy in a subset of LMS patients. more...

Es wird uber einen metachronen multifokalen Riesenzelltumor des Knochens (RZTK) berichtet. Der Patient bekam im Alter von 47 Jahren die Erstdiagnose eines RZTK im linken Oberarmknochen. Im Laufe seiner Krankengeschichte wurde ein weiterer RZTK im Kopf des vierten linken Mittelhandknochens und ein dortiges Lokalrezidiv nachgewiesen. Alle Tumorlokalisationen besasen die fur RZTK charakteristische H3F3A-Mutation G34W, die mittels Sanger-Sequenzierung und einem mutationsspezifischen Antikorper detektiert wurde. Der Fall stellt die Erstbeschreibung eines multifokalen H3F3A-mutierten RZTK dar. more...

To establish a chordoma tissue cohort (n = 43) and to correlate localization, size, metastasis, residual disease (R-status), recurrences, histological subtype, matrix content, and Ki-67 proliferation index with patients’ overall survival (OS). We used routine histopathology supplemented by immunohistochemistry. In our patient cohort (median age 69 years, range 17 to 84 years) the median OS was 8.25 years. 24 chordomas were localized in the sacrum, 6 in lumbar vertebrae, 7 in thoracic and cervical vertebrae, 5 were limited to the clivus, and one was localized in the nasal septum. Ten patients had metastases, with pulmonary, nodal, and hepatic involvement. 23 patients had recurrent disease. 23 chordomas were classified as ‘not otherwise specified’ (NOS). Besides NOS, we found the following differentiation patterns: renal cell cancer like in six cases, chondroid in four cases, hepatoid differentiation in three cases, and anaplastic morphology in six cases. Ki-67 index of ≥10 %, presence of metastasis, and the low content of extracellular matrix were statistically linked to poor OS (p more...

To explore the diagnostic value of MRI-based 3D texture analysis to identify texture features that can be used for discrimination of low-grade chondrosarcoma from enchondroma. Eleven patients with low-grade chondrosarcoma and 11 patients with enchondroma were retrospectively evaluated. Texture analysis was performed using mint Lesion: Kurtosis, entropy, skewness, mean of positive pixels (MPP) and uniformity of positive pixel distribution (UPP) were obtained in four MRI sequences and correlated with histopathology. The Mann-Whitney U-test and receiver operating characteristic (ROC) analysis were performed to identify most discriminative texture features. Sensitivity, specificity, accuracy and optimal cut-off values were calculated. Significant differences were found in four of 20 texture parameters with regard to the different MRI sequences (p more...

Aims Giant cell tumour of the bone (GCTB) is a neoplasm predominantly of long bones characterized by the H3F3A mutation G34W. Conventional diagnosis is challenged by the tumour's giant cell-rich morphology, which overlaps with other giant cell-containing lesions of the bone. Recently, a monoclonal antibody specific for the H3F3A mutation has been generated. Our aim was to test this antibody on a cohort of giant cell-containing lesions. Methods and results We used the antibody for analysis of 22 H3F3A-mutated GCTB, including two patients with recurrences; for comparison we analysed a cohort of 36 H3F3A wild-type giant cell-rich lesions of the bone and soft tissue, containing one brown tumour, six aneurysmal bone cysts (ABC), six chondroblastomas, five non-ossifying-fibromas, two fibrous dysplasias, nine tenosynovial giant cell tumours, one giant cell-rich sarcoma and six osteosarcomas. Furthermore, among the 22 mutated cases, we included one GCTB with two recurrences and lung metastases; the patient was treated with the anti-receptor activator of nuclear factor κB (RANK) ligand denosumab. We show that all 22 H3F3A-mutated GCTB display strong nuclear H3.3 G34W staining in the neoplastic component, while the osteoclastic giant cells are negative. 36 H3F3A wild-type lesions are negative. The GCTB treated with denosumab revealed a reduction in the H3.3 G34W-positive tumour cells and a decrease in osteoclastic giant cells accompanied by matrix and osteoid formation. Conclusions We conclude that positive H3.3 G34W staining is a specific and sensitive method for detection of H3F3A-mutated GCTB. Denosumab treatment leads to a pathomorphosis of the lesion characterized by matrix and osteoid producing H3.3 G34W-negative stromal cells. more...

Purpose Malignant soft tissue tumours appear infrequently in comparison to benign lesions. Clinical misdiagnosis leads to inadequate or delayed therapy in many cases of soft tissue sarcoma. The present study explores the question if ultrasonography as a widely-used diagnostic tool allows for a discrimination of benign and malignant soft tissue tumours. Materials and methods In a prospective study over a period of 8 years 224 histologically ascertained solid soft tissue tumours, thereof 120 sarcomas and 27 aggressive benign lesions were investigated by B-mode and colour Doppler sonography. The echotexture was analysed computer-based using the parameters echogenicity, homogeneity and vascularisation in all lesions. Results Different tumour groups showed typical patterns of echotexture, which enabled a classification using 6 categories, distinguishing homogenous hyperechoic, heavily inhomogeneous and homogenous hypoechoic lesions, each group linked to an elevated or low vascularisation. Implementation of the proposed classification revealed a sensitivity in the detection of soft tissue sarcomas and aggressive benign lesions of 94.4 % with a specificity of 79.7 % and an accuracy of 89.7 %. Conclusion Ultrasonography allows for a determination of the diagnostic and therapeutic procedure in soft tissue tumours. Due to the fact that soft tissue sarcomas present hypervascularised almost exclusively, predominantly homogenous hypoechoic, rarely homogenous hyperechoic, and aggressive benign tumours present homogenous hypoechoic predominantly, such patterns require a biopsy prior to further surgical therapy. However, in homogenous hyperechoic lesions displaying a low blood flow either a primary resection or a conservative treatment with follow-up examinations can be discussed depending on clinical findings and history of the patient. Although the group of heavily inhomogeneous tumours within our collective consisted of benign lesions exclusively, biopsy should be recommended in theses cases in order to exclude a soft tissue sarcoma. more...

The purpose of this study was to evaluate prospectively, whether integrated 2-deoxy-2-[(18)F]fluoro-D: -glucose positron emission tomography-computed tomography (FDG-PET-CT) is more accurate for determination musculoskeletal tumors compared with separate interpretation of CT and FDG-PET, because most of the current clinical data come from patients studied with PET.Eighty patients with newly diagnosed musculoskeletal tumors underwent FDG-PET-CT. CT, FDG-PET, and FDG-PET-CT were interpreted separately to determine the performance of each imaging modality.Assuming that equivocal lesions are benign, performance of diagnostic tests was as follows: sensitivity, specificity and accuracy for CT alone was 81, 84, 83%, for PET 71, 82, 76, and for PET-CT 80, 83 and 86%. Assuming that equivocal lesions are malignant, sensitivity, specificity, and accuracy for CT was 61, 100, 70%, for PET 69, 100, 79, and for PET-CT 69, 100 and 79%.Combined FDG-PET-CT reliably differentiates soft tissue and bone tumors from benign lesions. The value of the information provided by FDG-PET-CT for planning surgical procedures must be evaluated in further studies. more...

Stem loosening and stress-shielding are problems encountered in cemented hip arthroplasty. Could proximal stem fixation by partial cementing solve the problem? More physiological transmission of forces with only proximal cement fixation seems to be possible with this recent development (Z-stem, Option 3000, Mathys Orthopaedics, Bettlach, Switzerland). In a prospective clinical trial, this new implant was used for total hip arthroplasty in human patients. One hundred and thirty-three (133) total hip replacements in 123 patients were performed between April 1996 and January 2003. All of them were followed up regularly; 53 were analysed with the EBRA-FCA method (Einzel Bild Röntgen Analyse--femoral component analysis), whereas the rest were analysed using conventional follow-up X-rays. Eighty-six (86) patients with 95 hips could be examined in August 2004 to obtain mid-term results. At this stage, the mean follow-up time was 61 months (5.08 years), with a maximum of 100 months (8.33 years). Up to October 2004, nine cases needed a revision. The clinical data collected reported an average Harris Hip Score of 89.3 (good). The EBRA-FCA analysis reported a mean subsidence of less than 1.5 mm after the first two years, under the EBRA threshold of predicted loosening. At the latest follow-up (at an average of 61 months), there was an average stable subsidence of 2.4 mm in general. Eight (8) patients presented with subsidence of more than 5 mm. The results of the new implant seem to be encouraging. Finally, comparing our results to other fixation concepts will require longer follow-up periods. more...

Proximal stem fixation by partial cementing is a new concept in hip arthroplasty. We conducted a prospective clinical and radiological analysis to evaluate the preliminary outcome of this new technique with the Option 3000® stem (Mathys Orthopaedics, Bettlach, Switzerland). One hundred and thirty-three hip replacements in 123 patients have been performed between 1996 and 2003: All of them were followed up regularly both clinically and radiological and 53 were analysed with the EBRA-FCA method. Eighty-six patients with 95 hips could be seen in August 2004. At this point of time, the mean follow-up time was 61 months (5.08 years) with a maximum of 100 months (8.33 years) The clinical data reported an average Harris Hip Score of 85.5. Nine stems had to be exchanged over the period of study. The EBRA-FCA analysis reported a mean subsidence less than 1.5 mm after 2 years, then an average stable subsidence of 2.4 mm. So the results are similar to the early results obtained with other fixation concepts and the long-term results appear promising. more...

Endoscopic minimally invasive techniques have become an established method of fracture stabilisation in the spine. In view of this fact, anterior stabilisation strategies must be reconsidered, as monosegmental A 3.1 compression fractures are increasingly being stabilised endoscopically from the anterior aspect using minimally invasive techniques. This study investigated the biomechanical necessity of anterior two-point or four-point stabilisation in the instrumentation of mono- and bisegmental fractures. In three biomechanical in vitro studies, burst fracture stabilisation was simulated, and anterior short fixation devices were tested under load with pure moments up to 3.75 Nm to evaluate the biomechanical stabilising characteristics of different kinds of instrumentations in flexion/extension, lateral bending, and axial rotation. Only anterior four-point stabilisation resulted in sufficient primary stability both in mono- and bisegmental instrumentation and therefore represents the standard procedure in open as well as in minimally invasive spinal surgery. more...

Die Differenzierung zwischen degenerativen Krankheitsbildern der Halswirbelsaule (HWS) und unfallbedingten Beschwerden erfordert unfallanalytische Betrachtungen. Probandenversuche ergeben Daten im Niedrigenergiebereich, unfallanalytische Untersuchungen zu strukturellen Verletzungen der HWS fehlen. Im Zeitraum vom 01.01.2000 bis 30.04.2002 wurden 15 Patienten mit strukturellen Schaden der HWS nach einem Pkw-Unfall in der Unfallchirurgischen Klinik der Universitat Ulm behandelt. In 11 Fallen konnte eine unfallanalytische Begutachtung durch die DEKRA (Ulm) angefertigt werden. Strukturelle Verletzungen der HWS konnen bei seitlicher Krafteinleitung auch im Geschwindigkeitsbereich δv=10 km/h auftreten. Verletzungen der Ligg. alaria entstehen bei Frontalkollisionen mit erheblichen Differenzgeschwindigkeiten. Unfallanalytische Daten struktureller Verletzungen der HWS mussen in Kausalitatsbetrachtungen der Distorsion der HWS Berucksichtigung finden. more...

We investigated the osseointegration of solvent-preserved, xenogenous cancellous bone blocks in the treatment of unstable fractures of the thoracolumbar junction. In 22 patients, the anterior repair procedure was performed by thoracoscopy or minimally invasive retroperitoneal surgery. Twenty-two patients had undergone monosegmental anterior fusion and were surveyed prospectively. Solvent-preserved, bovine cancellous bone blocks were used in 11 patients; iliac crest bone graft was used in the others. Follow-up after 12 months included CT scans, which revealed successful osseointegration in eight out of 11 patients who had received autogenous iliac crest bone grafts, while three patients showed a partial integration. There were no graft fragmentations. In patients who had received solvent-preserved, xenogenous cancellous bone blocks, complete osseointegration was achieved at the graft–bone interface in only two out of 11 cases, after 1 year. Partial integration was found in three patients. In view of these results, autogenous iliac crest bone grafts are still the unrivalled standard for defect repair in spinal surgery. more...

Whether injuries to the alar ligaments could be responsible for complaints of patients having whiplash injury in the upper cervical spine is still controversially discussed. It is known that these ligaments protect the upper cervical spine against excessive lateral bending and axial rotation movements. The objective of the present in vitro study was therefore to examine whether the alar ligaments or any other structures of the cervical spine are damaged in side collisions. In a specially designed acceleration apparatus, six human osteoligamentous cervical spine specimens were subjected to incremental 90 degrees side collisions from the right (1 g, 2 g, 3 g, etc.) until structural failure occurred. A damped pivot table accounted for the passive movements of the trunk during collision, and a dummy head (4.5 kg) ensured almost physiological loading of the specimens. For quantification of functional injuries, the three-dimensional flexibility of the specimens was tested in a spine tester before and after each acceleration. In all six specimens, structural failure always occurred in the lower cervical spine and always affected the facet joint capsules and the intervertebral discs. In four specimens, this damage occurred during the 2 g collision, while in the other two it occurred during the 3 g and 4 g collision, respectively. The flexibility mainly increased in the lower cervical spine (especially in lateral bending to both sides) and, to a minor extent, in axial rotation. In vitro low-speed side collisions caused functional and structural injury to discoligamentous structures of the lower cervical spine, but did not damage the alar ligaments. Since the effects of muscle forces were not taken into account, the present in vitro study reflects a worst-case scenario. Injury thresholds should therefore not be transferred to reality. more...

A new instrumentation system for ventral stabilization of the spine that can be used for an endoscopic and minimally invasive approach was developed. We describe the implantation technique and report on the first clinical results. This prospective study covers the first 45 patients to undergo this new technique since it was introduced in 1999. In all patients the operation was successfully performed in a completely minimally invasive procedure. Mono- and bisegmental stabilization was performed mainly at the thoracolumbar junction after initial posterior instrumentation in most cases. Lesions varied from fresh/old fractures to metastases (T5–L3). Pre- and postoperative follow-up included clinical examination and radiological visualization via X-ray and computed tomographic scan. Our experience with this minimally invasive procedure demonstrated the feasibility of the method. more...

With the second amendment to the Ordinance on Occupational Diseases (BeKV) of 18 December 1992, discogenic diseases of the spine are included in the disease register of occupational diseases for the first time. If occupations that impose stress on the spine have been practised for many years, the possibility exists of recognizing degenerative diseases as an occupational disease. In assessment practice, the radiological data on the spine exposed to stress is compared with that of regions which are remote from the stress (cervical/thoracic spine). This pattern of the distribution of degenerative disease is then used as the basis for determining a causal relationship between the occupation causing the stress and disease of the axial skeleton. The pattern of degeneration of the cervical spine was investigated in two groups, one with ( n =153) and one without ( n =333) occupations that impose stress on the lumbar spine. A cumulative score of degenerative changes was elaborated and presented as a new classification. No differences were found between the groups with regard to either the frequency of occurrence, segmental distribution or severity of disease. In both groups, degenerative changes correlated with age. The prevailing assessment practice is discussed on the basis of these data. more...

Object. The authors conducted a study to investigate the biomechanical in vitro influence of a new anchorage system for fixation of anterior stabilization devices and the possibility of using additional cement after screw insertion to compensate for poor bone quality. The incidence of osteoporosis-related fractures has increased nearly twofold in the last decade. Because of problems associated with anterior screw fixation such as loosening, mechanical failure, and the weakness of osteoporotic bone, current surgical treatments of vertebral body (VB) fractures are problematic. This is due to poor fixation strength of anterior screws in the adjacent segments. The aim of this study was to determine whether a new cemented and uncemented VB screw provides improved primary stability following placement of anterior instrumentation in cases of fracture. Methods. The primary stability-related parameters of a new uncemented/cemented screw were compared with those of conventional monocortical screw fixation in a burst fracture model in which strut graft and anterior overbridging instrumentation were used. The use of the new uncemented screw improved the range of motion (ROM) of the stabilized spine in flexion—extension by approximately 22%, in rotation by 20%, and in lateral bending by 15%. Additional cementation improved the ROM by approximately 41% in flexion—extension, 32% in rotation, and 30% in lateral bending compared with conventional monocortical screw fixation. Conclusions. The new cannulated screw improves fixation strength and primary stability parameters. It is useful in the initial treatment of fractures in cases of poor bone quality and as a rescue device if previously inserted screws do not remain securely in place. more...

Some 30% of unstable vertebral fractures of the thoracic and lumbar spine involve a destruction of the ventral column and thus of the supporting structures of the spine. This requires extensive surgical reconstruction procedures, which are carried out using minimally invasive techniques. The disadvantages of the minimally invasive methods are the high cost, the technical equipment and the expenditure of time required in the initial phase for the performance of the surgical procedure. With the structural reform of the health care system in the year 2000, the private-sector regulatory bodies were called upon to introduce a flat-rate compensation system for hospital services according to section 17b of the Hospital Law (KHG). The previous financing system which involved per-diem operating cost rates has thus been abolished. Calculations of individual entities are now required. Considering the case values to date, a contribution margin deficit of EUR 4628.45 has been calculated for our patients with fractures of the thoracic and lumbar spine without neurological defunctionalization symptoms. An economically efficient medical care is thus no longer possible. Consequently, an adjustment of the German relative weights must urgently be demanded in order to guarantee a high-quality medical care of patients. more...

Der Einfluss von zusatzlichen Verletzungen dorsaler Wirbelsaulenstrukturen im Rahmen einer Fraktur auf die Stabilitat ventraler Stabilisierungen ist weitgehend unbekannt. Die Zementierung der ventralen Schrauben ist eine Moglichkeit die Stabilitat von ventralen Systemen besonders bei schlechter Knochenqualitat zu erhohen. Mit Hilfe eines neu entwickelten Schraubdubels lasst sich bei schlechter Haltefestigkeit eine genau definierte Menge Knochenzement uber Langsschlitze durch den hohlen Schraubdubel applizieren. more...

Die Etablierung minimal-invasiver Techniken in der Frakturbehandlung der Wirbelsaule wurde durch das Fehlen geeigneter Implatate und Instrumente erschwert. Mit der Entwicklung des MACS-TL-Systems® ist nun ein an die endoskopische Technik angepasstes System konzipiert worden, welches eine komplett endoskopische Stabilisation von Th5 bis L1, ggf. mit endoskopischem Zwerchfellsplitting von L1 bis L2 und von L2 bis L4 retroperitoneal mono- und mehrsegmental ermoglicht. more...

Study Design. Conditioned media (CM) of cartilaginous endplates (CEPs) of intervertebral discs were analyzed in a bioassay with regard to their influence on matrix turnover and inflammatory factors on nucleus pulposus (NP) cells of the same patient. CEP tissue underwent further histological and ultrastructural analysis. Objective. To identify possible interactions between the CEP and the disc via molecular factors that may influence disc matrix degradation and to determine degenerative changes of CEP tissue. Summary of Background Data. Impaired endplate perme-ability due to degeneration and calcification is considered to be a key contributor to disc degeneration. An upregulation of metalloproteinases and inflammatory cytokines has been observed in degenerated intervertebral discs. Possibly, the CEP contributes to the regulation of disc matrix degradation via molecular interactions with the disc tissue. Methods. CEP and NP cells from the same patients (n = 6) were investigated in a bioassay with regard to their influence on matrix turnover and inflammatory factors. We determined gene expression of NP cells in alginate beads that were exposed to CM of CEP punches (CEP-CM) from the same patients. The CEP-CMs were analyzed by protein array for inflammatory cytokines. Further CEP samples underwent histological (n = 15) and ultrastructural analysis (n = 8) to determine alterations of cell and matrix structure. Results. NP cells exposed to their donor-corresponding CEP-CM significantly upregulated interleukins (IL-6, IL-8) and matrix metalloproteinase (MMP-3, MMP-13) expression, and significantly decreased aggrecan and collagen type 2 expression. Proinflammatory cytokines were identified in the CEP-CM. The occurrence of apoptotic cells and degraded matrix fragments varied strongly between donors. Conclusion. Our results indicate interactions between the CEP and the NP tissue via molecular factors that upregulate matrix degrading enzymes and inflammatory cytokines and thereby influence the pathophysiology of disc degeneration. Ongoing investigations will further identify the regulative role of potential molecular factors that are responsible for these degenerative alterations. Conclusion. Level of Evidence: N/A more...

Die ventrale interkorporelle Spondylodese und Instrumentation gilt als Standardverfahren in der Versorgung instabiler Verletzungen der HWS. Ziel der Untersuchung war die Erhebung der Behandlungsergebnisse bei temporarer Stabilisation verletzter Bewegungssegmente der HWS. In der Zeit von 1990–1998 wurden an der Universitat Ulm wegen Verletzungen der Halswirbelsaule insgesamt 155 Patienten operativ versorgt. Bei 22 Patienten erfolgte eine uberbruckende Instrumentation des Bewegungssegmentes ohne Fusion, eine Implantatentfernung konnte inzwischen bei 12 Patienten vorgenommen werden. Eingangskriterien waren eine Altersbegrenzung von unter 45 Jahren sowie ein Verletzungstyp mit fehlender frakturbedingter knocherner Spinalkanaleinengung. Ubersichtsradiographisch darstellbare degenerative Veranderungen zum Verletzungszeitpunkt stellten ein Ausschlusskriterium dar. Bei der Nachuntersuchung waren alle Patienten beruflich rehabilitiert, 11 von 12 Patienten waren mit dem Behandlungsergebnis sehr zufrieden oder zufrieden. Sekundare Instabilitaten sowie posttraumatische Bandscheibenvorfalle waren in keinem Fall aufgetreten. Eine Restmobilitat im verletzten Bewgungssegment konnte bei 8 Patienten nachgewiesen werden. Der Verzicht auf eine Fusion bei ventralem Vorgehen fuhrt zur Verkurzung der Operationszeit, Komplikationsmoglichkeiten von Seiten der Spaninterposition und der Spanentnahme entfallen. more...

Anterior intervention of metastatic lesions of the spine can accomplish relief of pain, spinal decompression, and restoration of spinal stability. Ventral vertebral body replacements have been developed to provide these conditions but there have been problems with loosening at the implant-bone interface, mechanical failure, and X-ray artifacts from the metal. Intraoperative stability of the vertebral body replacement is especially critical to avoid loosening of the implant and to achieve long-term bony incorporation. This study compared the biomechanical performance in vitro of a new radiolucent system for vertebral body replacement to three currently marketed systems. The new system features a composite bioglass-polyurethane body and a new configuration of polymeric fastening hardware. Range of motion, neutral zone, and several interfacial motion parameters were measured under pure moments of 3.75 Nm in the three anatomical directions. The new system provided the significantly highest restraint of motion for all parameters. Mechanically, the new system is preferable at least initially to a sampling of systems representative of those currently used. more...

Object The cervical spine in a patient with ankylosing spondylitis (AS) (Bechterew disease) is exposed to maximal risk due to physical load. Even minor trauma can cause fractures because of the spine’s poor elasticity (so-called bamboo spine). The authors conducted a study to determine the characteristics of cervical fractures in patients with AS to describe the standard procedures in the treatment of this condition at two trauma centers and to discuss complications of and outcomes after treatment. Methods Between 1990 and 2006, 37 patients were surgically treated at two institutions. All patients were examined preoperatively and when being discharged from the hospital for rehabilitation. Single-session (11 cases) and two-session anterior–posterior (13 cases), anterior (11 cases), posterior (two cases), and laminectomy (one case) procedures were performed. The injury pattern, segments involved, the pre- and postoperative neurological status, and complications were analyzed. Preoperative neurological deficits were present in 36 patients. All patients experienced improvement postoperatively, and there was no case of surgery-related neurological deterioration. In patients in whom treatment was delayed because of late diagnosis, preoperative neurological deficits were more severe and improvement worse than those treated earlier. The causes of three deaths were respiratory distress syndrome due to a rigid thorax and cerebral ischemia due to rupture of the vertebral arteries. There were 12 perioperative complications (32%), three infections, one deep venous thrombosis, five early implant failures, and the three aforementioned fatalities. There were no cases of epidural hematoma. In all five cases in which early implant failure required revision surgery, the initial stabilization procedure had been anterior only. A comparison of complications and the outcomes at the two centers revealed no significant differences. Conclusions The standard intervention for these injuries is open reduction, anterior decompression and fusion, and anterior–posterior stabilization; these procedures may be conducted in one or two stages. Based on the early implant failures that occurred exclusively after single-session anterior stabilizations (five of 10—a failure rate of 50%), the authors have performed only posterior and anterior procedures since 1997 at both centers. Diagnostic investigations include computed tomography scanning or magnetic resonance imaging of the whole spine, because additional injuries are common. The causative trauma may be very slight, and diagnosis may be delayed because plain radiographs can be initially misinterpreted. In cases in which diagnosis is delayed, patients present with more severe neurological deficits, and postoperative improvement is less pronounced than that in patients in whom a prompt diagnosis is established. Because of postoperative pulmonary and ischemic complications, the mortality rate is high. In the present series the mortality rate was lower than the mean rate reported in the literature. more...

Several instrumentation systems and operative techniques for the operative treatment of fractures of the spine have been developed and marketed in the past. The surgical goals are decompression of the spinal canal, reduction of spinal deformities, and maintenance of stable fixation of the spine to permit early mobilization. Recent biomechanical studies have reported themechanical characteristics and primary stabilities of several anterior, posterior, and combined instrumentation systems in worst-case models [10, 21, 33–37, 41]. Bone grafting and single ventral instrumentation has been shown to be more effective in restoring acute stability than single dorsal instrumentation [36]. Despite this, dorsal implants have become a staple in the treatment of fractures without neurological deficit for their decided advantages. In the treatment of fractures with spinal cord compression, posterior instrumentation may provide indirect decompression of retropulsed intracanal bone fragments with ligamentotaxis through distraction. However, reduction of intracanal bone fragments by indirect decompression leaves uncertain the degree of ligamentous continuity to the fragment, retropulsion of the fragment, and the displacement pattern of the fragment. These criteria are difficult to assess preoperatively and result in variable degrees of reduction. Short segment pedicle instrumentation techniques have also been associated with loss of reduction and instrumentation failures, particularly at the thoracolumbar junction [7, 10, 11, 22, 39]. Often a second anterior intervention is necessary and is associated with greater approach-related trauma, increased blood loss, a higher risk of infection, and the problem of screw hold in the ventral vertebral body. Also anterior surgery is technically demanding and is not generally a familiar procedure to orthopedic surgeons, especially under emergency conditions [12, 18, 42, 43]. Suitable anterior instrumentation systems, however, have demonstrated biomechanical in vitro superiority compared to single dorsal [36]. Also the direct anterior approach provides an optimal visibility environment for recovery of the neural tissue and allows reconstruction, alignment, and immediate stabilization of the anterior load-bearing column through strut grafting [1, 12, 18, 34–36, 41–43]. The desirable intervention seems to be an initial ventral decompression and stabilization endoscopically and thoracoscopically to minimize the approach and other complications related with conventional anterior intervention, and to maximize the advantage due to an optimal visibility environment for recovery of the neural tissue and stabilization. A single endoscopic intervention and stabilization may also prevent a second-stage procedure with the result that hospital stay is shorter and return to work is sooner. Previous investigations have focused on degenerative diseases of the spine, showing the advantages of endoscopic techniques to be striking in safety and cost [2–5, 8, 9, 13–17, 20, 29–32, 38]. more...

The influence of additional dorsal structure damage on anterior stabilization of a thoracolumbar fracture is still unknown. Screw-cement enhancement can be used to reinforce the stability of anterior instrumentation. We have developed a new anchorage system for fixation of anterior stabilization devices, adapted through geometric optimization and the additional option of cementation after screw insertion. This study examines the question of whether this enhancement is strong enough to enable a single anterior procedure and still compensate for dorsal instability. Various spinal reconstruction procedures were evaluated biomechanically in an increasing ventrodorsal instability model for thoracolumbar fracture stabilization. A biomechanical in vitro study, simulating stabilized defect situations (corporectomy/vertebrectomy) with strut grafting and overbridging instrumentation, was performed on six human T10–L2 cadaveric specimens. The primary stability parameters, range of motion and neutral zone, were evaluated with or without anterior screw-cement enhancement. This was compared with a single conventional anterior stabilization without a dorsal defect (corporectomy). It was also compared with a single anterior, posterior or combined procedure in the presence of additional dorsal structure damage (vertebrectomy). The use of an additional cementable screw dowel enhanced the primary stability of the anterior instrumentation, compensating for dorsal instability. These results are warranted for the clinical use of minimally open or endoscopic techniques, creating the highest possible primary stability while performing a single anterior enhanced instrumentation with a tissue-preserving approach. more...

Study design Loads acting in an internal fixator measured in vitro under the application of pure moments such as those commonly used for implant testing and basic research were compared with loads measured in 10 patients in vivo. Objectives To investigate whether these recommended loading conditions are valid by comparing in vivo measurements and those obtained in an in vitro experiment. Summary of background data Pure bending moments are often preferred as loading conditions for spinal in vitro testing, either for implant testing or basic research. The advantage of this loading pattern is that the bending moment is uniform along the multisegmental specimen. However, functional loading of the spine by muscles or external loads subjects the spine to a combination of forces and moments. Methods In an in vivo experiment, loads acting on an internal spinal fixator in 10 patients were determined before and after anterior interbody fusion during flexion, extension, left and right lateral bending, and left and right axial twisting of the upper body with the patient standing. For comparison, an equivalent in vitro data set was created with 7 human lumbar specimens in which the same type of fixator was used. All specimens were tested under the application of pure bending moments in the three main motion planes in the intact state with fixator, after corpectomy, and with bone graft. Results Consistent qualitative agreement between in vivo and in vitro measurements for the loads acting in the internal spinal fixator were found for axial rotation and lateral bending. For flexion and extension, reasonable agreement was found only for the intact spines with fixators. After corpectomy and after inserting a bone graft, the median values for axial force and bending moment in the sagittal plane in vitro did not agree with in vivo measurements. An axial preload in the in vitro experiment slightly increased the axial compression force and flexion bending moment in the fixators. Conclusions The application of pure moments to intact lumbar spinal specimens in vitro produces forces and moments in implants comparable with loads observed in vivo. During basic research on intact specimens or implant testing involving a removed disc or corpectomy, muscle forces are necessary to simulate realistic conditions. more...

In this study, the three-dimensional stabilizing capabilities of the AO-Internal Fixator (IF) and the new Universal Spine System (USS) were investigated. Both devices were tested without and with the cross-link system (IF, IFC, USS, USSC). To determine biomechanical characteristics, a human thoracolumbar spine instability model with resection of the vertebral body Thl2 was created.The vertebral body was replaced by a spacer and transpedicular posterior stabilization was performed from Th11 to L1. All devices reduced the range of motion (ROM) significantly compared to the values of the intact specimen. In flexion the IFC showed the highest reduction of ROM (85 % of intact), followed by the USSC, USS and IF (79 % of intact). In extension the ROM was restored again most by the IFC (52% of intact), followed by the USSC, IF and USS (44% of intact). In lateral bending stability was provided by the USSC (right 78% and left 81 % of intact), followed in right lateral bending by the IF, IFC and USS and in left lateral bending by the USS, IF and IFC. In axial rotation the ROM was reduced primary by the IFC (right 51 % and left 46 % of intact), followed in right axial rotation by the USS, USSC and IF, in left axial rotation by the USSC, USS and IF. Additional stability by crosslinking has been provided in the IF and the USS in flexion and extension, in the USS in lateral bending and in the IF in axial rotation nonsignificantly. The neutral zone (NZ) was reduced by posterior instrumentation in flexion/extension and right/left lateral bending significantly. In axial rotation only the USSC decreased the NZ below intact levels. The study showed no statistical significant differences in the stabilizing capabilities of the USS compared to the IF. For both implants the cross-link system increased stability in the choosen instability model insignificantly only. more...

Metastatic spine lesions frequently require corpectomy in order to achieve decompression of the spinal cord and restoration of spinal stability. A variety of systems have been developed for vertebral body replacement. In patients with prolonged life expectancy due to an improvement of both systemic and local therapy, treatment results can be impaired by a loosening at the implant-bone interface or mechanical failure. Furthermore, early detection of a metastatic recurrence using sensitive imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) is possible in these patients without artefact interference. The aim of our pilot study was to evaluate the clinical applicability and results of a new radiolucent system for vertebral body replacement in the lumbar spine. The system consists of bone-integrating biocompatible materials – a polyetherurethane/bioglass composite (PU-C) replacement body and an integrated plate of carbon-fibre reinforced polyetheretherketone (CF-PEEK) – and provides high primary stability with anterior instrumentation alone. In a current prospective study, five patients with metastatic lesions of the lumbar spine were treated by corpectomy and reconstruction using this new system. Good primary stability was achieved in all cases. Follow-up (median ¶15 months) using CT and MRI revealed progressive osseous integration of the PU-C spacer in four patients surviving more than 6 months. Results obtained from imaging methods were confirmed following autopsy by biomechanical investigation of an explanted device. From these data, it can be concluded that implantation of the new radiolucent system provides sufficient long-term stability for the requirements of selected tumour patients with improved prognosis. more...

Several instrumentation systems and operation techniques for the operative treatment of fractures of the spine have been developed and marketed in the past. The surgical goals are decompression of the spinal canal, reduction of the spinal deformities, and maintenance of stable fixation of the spine to permit early mobilization. more...

In April 2010, a 19-year-old soccer player presented with a 4-week history of pain after a tap against his right knee. Medical and family histories were unremarkable and no abnormalities were found on physical examination. A radiograph of the right knee showed osteolytic lesions in the distal femur and the head of the tibia. On magnetic resonance imaging, the epiphyseal lesions were visualized as cystic and nonsclerotic and extended to the articular surface of the distal femur and proximal tibia (Figure 1). Soft tissue extension was suspected from the tibia. Laboratory test results showed normal blood cell count, renal function, and concentration of C-reactive protein. Aneurysmatic bone cysts were suspected and a biopsy was performed. Histopathological examination detected spindle cell infiltrates with hemorrhages, fragmented trabecular bone, and numerous osteoclastic giant cells proliferating at a rate of 10% suggesting an aggressive giant cell lesion. Since it was still not determined whether the lesions were malignant, flourodeoxyglucose F 18positron emission tomography/computed tomographywasperformedand foundadditional lesions in the left distal femur and the leftmandible. Biopsyof themandible showed the same type of tissue as seen in the right femur and tibia. Quiz at jamasurgery.com A B more...

This paper compares seven scoring systems to assess their effectiveness in predicting overall survival time in patients with spinal metastases. Sixty-nine patients were evaluated in a prospective fashion using the eight parameters that constitute these different scoring systems. The following preoperative predictive systems were assessed: Tokuhashi score; Sioutos score; Tomita score; Van der Linden score and Bauer score. The basic intention of this paper is interesting. Many scores have been evaluated in the past, but there is a lack of one clinical useful single score. In the clinical daily routine it is always necessary to use more scores with different focuses. Due to this paper the modified Bauer scoring system appears to be the most effective tool. Of the seven parameters assessed location, general condition, number of extraspinal bone metastases, number of visceral metastases, primary tumor, severity of spinal cord palsy and pathological fractures only two, visceral metastases and origin of primary tumor were significant. Nevertheless, to make a recommendation 69 patients included in this work with low numbers concerning each type of primary tumor are not enough to give a significant answer on the initial hypothesis of this paper. Therefore, one must also remain skeptical about drawing definitive conclusions [breast (12), multiple myeloma (10), prostate (7), metastasizing hemangioendothelioma (1), hemangiopericytoma (1), thyroid (1), non-Hodgkin lymphoma (1), kidney (15), uterus (2), tonsil (1), epipharynx (1), femoral synovial sarcoma (1), malign thymoma (1), lung (6), melanoma (2), malignant teratoma (1), liver (1), stomach (1), colon (1), sigma (1), rectum (1), pancreas (1)]. In addition, scores for spinal metastases may furthermore be highly influenced by the effectiveness of existing interdisciplinary therapies present at the time of the creation of the score. However, the prementioned scores have been evaluated in range of two decades. New developments in medical oncology (like tyrosine kinase inhibitor for renal cell carcinoma) and radiotherapeutic fields, as well as in the surgical field (like kyphoplasty) will influence the overall survival time and therefore the existing scores by itself. Due to the increasing numbers of patients suffering on metastases of the spine and the upcoming developments in interdisciplinary therapies for each tumor type, a prospective multicenter study is mandatory. Within a multicenter study, maybe under the patronage of the European Spine Society enough patients could be included, especially considering each primary tumor type. If and only if this is done a current concept with definitive conclusions could be created in my opinion. more...