Surgical treatment of cervical spine fractures in ankylosing spondylitis patients: posterior stabilization using intraoperative CT scanner-based navigation.

INTRODUCTION: The authors analyzed a series of ankylosing spondylitis patients with cervical spine fracture undergoing posterior stabilization using spinal navigation based on intraoperative CT imaging. The purpose of this study was to evaluate the accuracy and safety of navigated posterior stabilization and to analyze the adequacy of this method for treatment of fractures in ankylosed cervical spine. METHODS: Prospectively collected clinical data, together with radiological documentation of a series of 8 consecutive patients with 9 cervical spine fracture were included in the analysis. The evaluation of screw insertion accuracy based on postoperative CT imaging, description of instrumentation-related complications and evaluation of morphological and clinical results were the subjects of interest. RESULTS: Of the 66 implants inserted in all cervical levels and in upper thoracic spine, only 3 screws (4.5%) did not meet the criteria of anatomically correct insertion. Neither screw malposition nor any other intraoperative events were complicated by any neural, vascular or visceral injury. Thus we did not find a reason to change implant position intraoperatively or during the postoperative period. The quality of intraoperative CT imaging in our group of patients was sufficient for reliable trajectory planning and implant insertion in all segments, irrespective of the habitus, positioning method and comorbidities. In addition to stabilization of the fracture, the posterior approach also allows reducing preoperative kyphotic position of the cervical spine. In all patients, we achieved a stable situation with complete bone fusion of the anterior part of the spinal column and lateral masses at one year follow-up. CONCLUSION: Spinal navigation based on intraoperative CT imaging has proven to be a reliable and safe method of stabilizing cervical spine with ankylosing spondylitis. The strategy of posterior stabilization seems to be a suitable method providing high primary stability and the conditions for a subsequent high fusion rate.

Instrumentation of C1 lateral mass via insertion of the posterior arch of atlas - a morphometric study.

INTRODUCTION: Instrumentation of the lateral mass of atlas via posterior arch attachment (PALMS) is a method that, unlike the traditional direct screw insertion into the lateral mass, prevents damage to the periarticular venous plexus and C2 nerve root. The method itself may be, however, limited by the anatomical situation. The small cranio-caudal pedicle dimension may lead to vertebral artery damage. The aim of this study was to use morphometric examination of CT findings from the healthy population to evaluate theoretical feasibility of this technique in a randomly selected population sample. METHODS: Morphometric measurements determining dimensions of C1 pedicle at the site of expected screw insertion were performed on reformatted parasagittal CT scans of 42 healthy probands. Using the software of the Jivex browser, we measured the minimum height of posterior arch insertion under the vertebral artery groove and evaluated the possibility of introducing 3.5 mm and 4 mm screws. RESULTS: The mean minimum height of the critical segment was calculated as 4.29 mm (left insertion 4.28 mm, right insertion 4.31 mm, range 3.02-5.62 mm). Despite the highest size in a female and the lowest in a male, the male population showed larger bone stock (mean of 4.71 mm: left connection 4.70 mm, right connection 4.71 mm) than the female one (mean of 4.29 mm: left 4.28 mm, right 4.31 mm). Overall, we found 59.5% insertions higher than 4 mm and 86.9% arch connections bigger than 3.5 mm. CONCLUSION: The anatomical situation allows inserting at least a 3.5mm diameter screw in a vast majority of cases. The posterior arch attachment point thus seems to be a suitable anatomical target for instrumentation of C1 lateral mass. Nevertheless, individual presurgical planning and intraoperative spinal navigation should be implemented, as well.

[The angular profile of a cage has no influence on segmental alignment after anterior cervical stand-alone interbody fusion]. / Úhlový profil kose neovlivní segmentální postavení pri prední krcní fúzi provedené metodou stand-alone.

PURPOSE OF THE STUDY: The original aim of this prospective semi-randomised study was to determine associations between segmental sagittal alignment after Anterior Cervical Discectomy and Fusion (ACDF) and subjective and clinical results. Two types of cages, cage P with parallel end-plates and cage A with 5-degree angulations, were used in the patients treated for degenerative conditions. MATERIAL AND METHODS: A total of 94 consecutive patients, 56 treated by single-level ACDF and 38 undergoing a two-level procedure, completed 8 years of follow-up. The patients in equally-sized A and P subgroups were examined at 6 weeks and 1, 2 and 8 years after surgery. The follow-up included X-ray in a neutral lateral position, a questionnaire assessing pain in neck and shoulder regions and JOA scores. The results including the cumulative incidence of surgical procedures indicated for adjacent segment diseases were statistically evaluated. RESULTS: An average increase in the lordotic angle at 6 weeks after surgery was 2.32° for the implant P and 2.02° for the implant A subgroup. During 8 years of follow-up the average values decreased to 1.51° and 1.36°, respectively. The proportion of patients with no or minimal neck and shoulder pain decreased, in subgroup P, from the initial 85% at 6 weeks to 59% at 8 years after the surgery and, in subgroup A, from 89% to 40 %. The average JOA score of 16 at 6 weeks in both subgroups, at 8 years, had a value of 15.9 in subgroup P and 16.0 in subgroup A. The cumulative incidence of surgery for adjacent segment disease 8 years was 8.3% for subgroup P and 6.3% for subgroup A. No statistically significant differences between the subgroups at any follow-up period were recorded in either morphological characteristics or clinical outcomes. CONCLUSIONS: The ability to lordotize a segment by stand-alone ACDF is below the angular resolution of current radiographic methods, irrespective of the sagittal profile of the implant used. Comparable morphological results haven´t been reflected by significant difference in subjective and clinical outcome and also in the incidence of surgery for adjacent segment disease. Such results were not expected and therefore post-operative sagittal alignment mechanisms in stand-alone cage assisted ACDF will require further investigation. Key words:cervical vertebrae, surgical technique, spinal fusion, sagittal alignment, clinical outcome.

[Intraoperative CT-based spinal navigation: the initial 295 implants experience]. / Navigace v páterní chirurgii zalozená na intraoperacním CT zobrazení: zkusenost s iniciálními 295 implantáty.

INTRODUCTION: The authors describe the system of spinal navigation based on intraoperative CT imaging and the results of an initial series of patients. MATERIAL AND METHODS: Spinal screws inserted during 50 surgical procedures in the period between November 2012 and October 2013 were evaluated for insertion accuracy, intraoperative complications and the accessibility of the method for the selected spinal level. RESULTS: Out of the total of 295 screws inserted throughout all the spinal levels from C0 to S1, only 4 (1.3%) pedicle screws were found to be incorrectly inserted: a single L5 screw breached the lower cortex of the pedicle, two thoracic pedicular screws penetrated the anterior margin of the vertebral body not exceeding 3 mm of the shaft length, and a single C3 pedicle screw penetrated the upper vertebral body end-plate. None of these complications caused morbidity or required re-operation. Intraoperative CT imaging together with the navigation procedure increased the time of surgery by 30 minutes on average and patient radiation exposure during the initial and accuracy control CT scan was increased. CONCLUSION: Our initial experience has shown that the CT-based computer-assisted spinal navigation system is a precise surgical modality. It enables higher accuracy in spinal screw positioning, resulting in lower surgical morbidity and increased safety for the patient. This benefit should outweigh the longer operation time as well as a higher radiation exposure of the patients.

Does sagittal position of the CTDR-related centre of rotation influence functional outcome? Prospective 2-year follow-up analysis.

PURPOSE: Recent studies describe significant rates of heterotopic ossification (HO) after cervical total disc replacement (CTDR). Little is known about the reasons, and one aspect that requires further in vivo investigation is the biomechanical alteration after CTDR and the role of the implant-related centre of rotation (CORi) in particular. The role of the sagittal position of the CORi on functional outcome in two versions of a semi-constrained disc prosthesis with sagittally different CORi is the topic of this study. METHODS: Patients were candidates for single-level CTDR between C3 and C7 who suffered from CDDD and received a standard or flat version of activ C™ (Aesculap AG, Tuttlingen). Clinical and radiographic assessments were determined preoperatively, intraoperatively, at discharge and again at 6 weeks, 6 months, 1 and 2 years. Radiographic examinations were performed independently using specialized quantitative motion analysis software. RESULTS: Clinical outcome improved significantly regarding NDI as well as VAS on neck and arm pain with no differences in mean improvement by study group. Segmental angle measures show a significantly better lordotic alignment for both groups after surgery, but the degree of correction achieved is higher in the flat group. Correlation analysis proves that the more anterior the CORi is positioned, the higher the lordotic correction is achieved (Pearson rho -0.385). Segmental ROM decreased in the standard group but was maintained for flat implants. At present, our data do not demonstrate a correlation between CORi and ROM at 2 years. Two years after surgery, severe HO grade III-IV was present in 31.6 % standard and 13.1 % flat cases with significant differences. Grouping according to HO severity showed comparable sagittal positions of CORi for flat implants but a more posterior position in the severe HO group for standard implants. CONCLUSIONS: Our results confirm the influence of CORi location on segmental alignment, kinematics and HO for a semi-constrained CTDR, but it also indicates a multifactorial process.

[Odontoid fracture combined with lateral atlanto-axial dislocation. Report of two cases]. / Zlomenina zubu cepovce II. typu spojená s laterální dislokací atlasu. Popis dvou prípadu.

The authors describe their experience with treatment of two neurologically intact male patients, aged 70 and 74 years, presenting with combined lateral atlanto-axial dislocation and odontoid type II fracture. The mechanism of these two craniovertebral junction injuries had been lateroflexion of the neck. The initial attempt at closed reduction using axial traction failed. The authors succeeded with a closed reduction maneuver under general anaesthesia in the first patient in whom long-term stability was achieved by transarticular C2-C1 fixation, together with interlaminar fusion. In the second patient, closed reduction was unsuccessful due to intra-articular soft tissue interposition. Release and reduction were achieved by instrumentation of C1 lateral masses and transpedicular anchorage of screws into the C2. The subsequent Harms C1-C2 stabilisation proved to be effective both in achieving long-term stability and segmental fusion of lateral masses. Aspects of biomechanics as well as a review of pertinent literature are presented.

[Minimally invasive cervical elastic laminoplasty - principles and surgical technique]. / Minimálne invazivní krcní elastická laminoplastika - principy a operacní technika.

PURPOSE OF THE STUDY: To present a new technique of minimally invasive decompression of the cervical spinal canal using elastic and plastic deformation of the laminae. MATERIAL AND METHODS: Short midline vertical incision provides an access to the superior aspect of the target spinous processes. Cranial edge of the lamina is located by a midline, muscle-sparing interspinous dissection. The spinous process is cut in mid-sagittal plane using a thin blade of an ultrasonic bone scalpel down to epidural space. The created sagittal cleavage of the spinous process is subjected to tension and elastic distraction by a custom-designed distractor (Aesculap, Germany). Gradual increase of the distraction force leads to a significant plastic deformation. This reduces the distraction force and allows for a wider exposure which, in turn, facilitates dural visualization, resection of the yellow ligament and undercutting of approximately a half of the adjacent intact laminae. After completion of decompression, the plastic arch expansion can be maintained either by interposed bone-graft or appropriately shaped cage secured by a circumferential suture to the spinous process. Soft tissue resection and permanent expansion of the laminae provide sufficient decompression of the cervical spinal cord. In multilevel stenosis, the desired laminae can be expanded using this technique. To achieve the same degree of canal expansion as that by a classic laminoplasty (C3-7), a skip technique can be utilized. This involves combining expansive laminoplasty of C4 and C6 with bilateral undercutting of C5 and partial undercutting of C3 and C7. This can be achieved through two short vertical incisions. Based on data and experience gained from testing on 11 cadavers, we applied this method in 7 patients requiring posterior cervical decompression. RESULTS: The spinous process or laminae fractured during expansion in the initial 4 patients and the procedure required conversion to a minimally invasive laminectomy. Further modification of the distractor and spinous process splitting technique resulted in elimination of this complication in subsequent cases. In all remaining patients, sufficient canal expansion was achieved by soft tissue resection and distraction of laminae, typically reaching 5 - 8 mm. Minimally-invasive muscle-sparing midline approach provided very positive functional results in terms of postoperative pain and range of motion allowing for immediate mobilization without external bracing. CONCLUSION: Minimally invasive, muscle sparing, expansive laminoplasty provides adequate spinal canal expansion. Use of this technique and its muscle-sparing nature potentially result in improvement of early functional outcomes when compared to standard laminoplasty techniques requiring lateral lamina-facet border exposure. However, the theoretical superiority of this technique will need to be clinically scrutinized in a well designed surgical outcome study.

[Mathematical simulation of biomechanical background of osteophyte formation in cervical vertebra]. / Matematický model biomechanického pozadí osteodegenerativního procesu krcního obratle.

PURPOSE OF THE STUDY: The aim of this study was to simulate different types of cervical vertebra loading and to find out whether mechanical stress would concentrate in regions known in clinical practice as predilection sites for osteophyte formation. The objective was to develop a theoretical model that would elucidate clinical observations concerning the predilection site of bone remodelling in view of the physiological changes inside the cervical vertebral body. MATERIAL AND METHODS: A real 3D-geometry of the fourth cervical vertebra had been made by the commercially available system ATOS II. This is a high-resolution measuring system using principles of optical triangulation. This flexible optical measuring machine projects fringe patterns on the surface of a selected object and the pattern is observed with two cameras. 3D coordinates for each camera pixel were calculated with high precision and a polygon mesh of the object's surface was further generated. In the next step an ANSYS programme was used to calculate strains and stresses in each finite element of the virtual vertebra. The applied forces used in the experiment corresponded in both magnitude and direction to physiological stress. Mechanical loading in neutral position was characterized by a distribution of 80% mechanical stress to the vertebral body and 10% to each of the zygoapophyseal joints. Hyperlordotic loading was simulated by 60% force transfer to the vertebral body end-plate and 20% to each of the small joint while kyphotic loading involved a 90% load on the vertebral body endplate and 5% on each facet. RESULTS: Mechanical stress distribution calculated in a neutral position of the model correlated well with bone mineral distribution of a healthy vertebra, and verified the model itself. The virtual mechanical loading of a vertebra in kyphotic position concentrated deformation stress into the uncinate processes and the dorsal apophyseal rim of the vertebral body. The simulation of mechanical loading in hyperlordosis, on the other hand, shifted the region of maximum deformation into the articulation process of the Z-joint. All locations are known as areas of osteophyte formation in degenerated cervical vertebrae. DISCUSSION AND CONCLUSIONS: The theoretical model developed during this study corresponded well with human spine behaviour in terms of predilection sites for osteodegenerative changes, as observed in clinical practice. A mathematical simulation of mechanical stress distribution in pre-operative planning may lead to the optimisation of post-operative anatomical relationship between adjacent vertebrae. Such improvement in our surgical practice may further reduce the incidence of degenerative changes in adjacent motion segments of the cervical spine and possibly also lead to better subjective and clinical results after cervical spine reconstruction.

[Solitary spinal osteochondroma. Case report]. / Solitární páterní osteochondrom diagnostikovaný u 75letého muze.

Spinal osteochondromas as solitary lesions are rare tumours of a maturing adolescent skeleton. The authors treated a 75-year-old man for low back pain and neurogenic claudication. Symptoms were attributed to a tumorous expansion originating from the spinous process and right lamina of L3 and expanding into the spinal canal and adjacent facet joints. The patient underwent marginal resection of the tumour together with transpedicular stabilization of the segment, and histological examination confirmed the diagnosis of osteochondroma. The patient remains without any complaint and there are no signs of local recurrence of the tumour 4 years after the surgery. The cases of osteochondroma in an aged spine published in the literature and pertinent aspects of this extremely rare condition are discussed. Key words: spinal tumors, osteochondroma.

Exophytic intramedullary mature teratoma of the conus medullaris: case report and review of the literature.

BACKGROUND: Intramedullary tumors affect a small but significant portion of patients with spinal tumors. Ependymomas and astrocytomas are the most common entities. The diagnosis of a mature teratoma is extremely rare, although not in the presence of associated developmental abnormalities. The medullary conus is the most common location. Such a case with caudal exophytic growth is presented here and the literature extensively reviewed. CASE PRESENTATION: Low back pain and muscle weakness led to diagnosis of a exophytic intramedullary lesion of the conus medullaris in a 52-year-old woman. After subtotal resection the symptomatology partially improved. Histopathological examination revealed mature teratoma. CONCLUSION: Literature review identified 68 cases of intramedullary teratomas. These should be considered in the differential diagnosis when an associated developmental abnormality is present. Subtotal resection is a valid alternative to radical tumor removal when neurological function is at risk. The prognosis of adult patients with intramedullary mature teratoma is excellent.

[Navigation techniques in surgery of cranio-cervical junction and upper cervical spine]. / Navigacní techniky v chirurgii kraniocervikálního prechodu a horní krcní pátere.

Spinal navigation has substantially advanced during the past ten years. Surgeons have gained sufficient skills and confidence, and have introduced this technology to the anatomically challenging region of the upper cervical spine and craniocervical junction. The detailed evaluation of individual anatomy, rational pre-operative planning and final intraoperative control improve the safety and precision of classical surgical procedures. As methods technologically evolve, indication criteria change accordingly, but the basic principles of a relevatn choice remain; these are to reduce morbidity due to its three main causes, i.e., mechanical, neurological and vascular. We present an overview of current techniques and discuss their applicability in the region of the upper cervical spine and craniocervical junction. The systems allowing us to obtain live images intra-operatively, such as fluoroscopy or intra.operative CT, seem to be most versatile and accurate, especially when combined with traditional virtual navigation systems. Based on case histories, the authors suggest trends in the development of this field, with a focus on minimally invasive techniques. Key words: navigation, upper cervical spine, craniocervical junction.

[Percutaneous CT-guided radiofrequency ablation in spinal osteoid osteoma treatment]. / Perkutánní CT-navigovaná radiofrekvencní ablace v terapii spinálních osteoidních osteomu

PURPOSE OF THE STUDY: Radiofrequency ablation is a minimally invasive method indicated in the treatment of bone tumors. Its effectiveness and safety have been reported in a number of studies concerned with the therapy of osteoid osteoma of extremities. However, only scarce information is available on effectiveness of ablation in osteoid osteoma of the spine. The aim of the study was to verify the efficacy of percutaneous CT-guided radiofrequency ablation on this indication. MATERIAL AND METHODS: This prospective study included four patients, three women and one man, with osteoid osteoma of the lumbar or sacral spine who were treated by percutaneous CT-guided radiofrequency ablation in the period from February 2002 to March 2005. Two tumors were found in the third lumbar vertebra, one in the fourth lumbar and one in the first sacral verstebra. The pre-operative pain values assessed on the visual analogue scale (VAS), and function restriction rated by the Oswestry Disability Index (ODI) were compared with the post-operative values at 2 years after surgery. Patients' satisfaction with surgical outcome was evaluated according to Odom's criteria. RESULTS: All four procedures were accomplished successfully in technical terms and the patients completed the two-year followup. All patients reported significant relief of pain immediately after surgery and this held even after 2 years. The average pre-operative VAS value of 8.3 was reduced to 2.45 at the final examination, and the pre-operative ODI of 70/100 improved to 95/100 post-operatively. The outcome of treatment rated by Odom's criteria was regarded as excellent. CONCLUSIONS: Percutaneous CT-guided radiofrequency ablation is an effective and safe method for treatment of spinal osteoid osteoma. It has advantages that could make it preferable to surgical excision of tumors. Key words: osteoid osteoma, computed tomography, radiofrequency ablation.

[Surgical treatment of fracture of the ring of axis - "hangman's fracture"]. / Chirurgické resení fraktury oblouku epistrofeu - "katovské zlomeniny".

PURPOSE OF THE STUDY: To evaluate surgical management of the fracture of the ring of axis (FRA), known as "hangman's fracture", and to discuss adequacy of this treatment. MATERIAL AND METHODS: Between 1994 and 2004, 41 patients with FRA were surgically treated in our hospital. We present a retrospective study of 30 cases treated by anterior cervical fixation and fusion and 11 cases treated by a posterior, CT-guided approach (published recently). Our diagnostic algorithm for evaluation of FRA included plain radiographs for basic diagnosis, detailed CT scan, MRI and finally passive lateral flexion-extension fluoroscopy (performed by physician) to assess stability. We also consider discography in selected cases, allowing further evaluation of discoligamentous injury. Fractures were classified according to Levine. Posterior compressive osteosynthesis according to Judet was performed in 11 patients with Levine type I fractures with fracture fragment distraction > 3 mm. Anterior graft and plate fixation was chosen in 30 patients with type II (25 patients) and type I (5 patients) fractures where C2/3 disc injury was confirmed by MRI or discography. There was no case of facet dislocation in our series (type III). Pain, motion restriction and overall satisfaction with neck status were assessed on a scale 1-5 (1 = best) in patients treated with anterior approach. Self-evaluation questionnaires were administered during follow-up (average, 7.3 years; 24 months to 11 years). RESULTS: Anatomically reduced fracture fusion was achieved in all cases (100%) at one year follow-up. Both autologous tricortical (22) and fibular allografts (8) were used for anterior approach. No perioperative complications occurred and no case was aborted. Average hospital stay in patients with standalone FRA was 6.8 days (3-15). Patients wore Philadelphia collar for 4-6 weeks. One patient died during follow up due to unrelated causes. None of the 29 patients treated with the anterior approach reported severe or very severe pain (grades 4 or 5). The average pain score was 1.28. Three patients with isolated FRAs reported slight subjective restriction of movement (grade 2). The "satisfaction with overall neck status" scale showed an average score of 1.62, never worse than grade 2. DISCUSSION: Despite increasing popularity of anterior surgical approach in the treatment of type II FRA, most authors still recommend conservative treatment. Surgical treatment is consensually recommended in type III fractures only. Type I is treated exclusively conservatively. There is currently no evidence-based data supporting any method of treatment of so called "hangman's fracture". The majority of treating surgeons do not consider the status of the intervertebral disc. Dynamic films, simulating the peak point of injury, are usually not performed. Hence, potentially unstable fractures are overlooked. This also explains the lack of long term follow-up data regarding the radiological status of C2/3 intervertebral disc as well as patients' subjective complaints. CONCLUSIONS: Surgery provides plausible results. Compared to conservative treatment, it can offer significant benefits: 1) immediate, better and stable reposition; 2) high fusion rate; 3) shortening of the treatment period with better quality of life. Contrary to conservative treatment modalities, surgery possesses a potential for further development.

[Classification-based surgical approach in surgical management of thoracolumbar fractures of the spine]. / Klasifikací rízená volba operacního prístupu pri operacním lécení zlomenin torakolumbární pátere.

INTRODUCTION: The decision on the surgical approach in the operative treatment of the fractures of thoracolumbar spine is possible only by following a detailed classification. However, the application of the classification systems is not reliable without a complex imagination of the bony and fibrous structures involved into the fracture. Pre-op investigation should include x-rays, CT-scans and MRI. MATERIAL AND METHODS: Patient series consists of 21 females and 43 males treated surgically for the unstable thoracolumbar fracture during 2001. The average age was 43 years. Patients suffering form osteoporosis, fresh spinal cord injury and multiple spine fractures were excluded. All fractures were examined by plain x-rays, CT-scans and MRI and classified according the AO-ASIF classification system. In patients with A-type fractures the single anterior approach was used. Patients with B- or C-type of fracture were operated by the posterior approach. These fractures were complementary classified according to the Load-sharing classification and those with 6 or more points were additionally operated also from the front. Patients were divided into the three groups: the anterior approach (22 pts), the combined procedure (22 pts) and the posterior approach (20 pts). In the third group, the hardware was removed after 15 months on average. No posterolateral fusion was carried out. Minimum follow-up was 22 months. RESULTS: No implant failure was found in any patient. No significant loss of correction was found in the first and the second group. The loss of correction in the third group was 3.1 degree on average. CONCLUSION: Overall graphical imagination of the thoracolumbar fractures (including MRI) is essential for their classification. The classification helps to choose the optimum surgical approach. The approach related to the fracture classification prevents the treatment failure.

The influence of interleukin-1beta on gamma-glutamyl transpepidase activity in rat hippocampus.

Brain infections as well as peripheral challenges to the immune system lead to an increased production of interleukin-1beta (IL-1beta), a cytokine involved in leukocyte-mediated breakdown of the blood-brain barrier. The effects of IL-1beta have been reported to depend on whether the route of administration is systemic or intracerebral. Using 50-day-old male rats, we compared the effects of IL-1beta on brain gamma-glutamyl transpeptidase (GGT; an enzymatic marker of brain capillary endothelium) at 2, 24 and 96 h after either an intravenous (i.v.) injection of 5 microg IL-1beta or an intracerebroventricular (i.c.v. - lateral ventricle) infusion of 50 ng IL-1beta. When the i.v. route was used, the GGT activity underwent small but significant changes; decreasing in the hippocampus 2 h after the i.v. injection, increasing 24 h later and returning to control levels at 96 h. No significant changes in the hippocampal GGT activity were observed at 2 and 24 h following the i.c.v. infusion. The GGT activity in the hypothalamus remained unchanged regardless of the route of IL-1beta administrations. Similar changes in GGT activity were revealed histochemically. The labeling was found mainly in the capillary bed, the changes being most evident in the hippocampal stratum radiatum and stratum lacunosum-moleculare. A transient increase in GGT activity at 24 h, together with a less sharp delineation of GGT-stained vessels, may reflect IL-1beta induced increased turnover of glutathione and/or oxidative stress, that may in turn, be related to altered permeability of the blood-brain barrier in some neurological and mental disorders, including schizophrenia.

[Multiple-level instrumented anterior cervical fusion: a risk factor for pseudoarthrosis? A prospective study with a minimum of 3-year follow-up]. / Je víceetázová instrumentovaná prední krcní fúze rizikovým faktorem vzniku pseudoartrozy? Prospektivní studie s minimálne 3letou délkou sledování.

PURPOSE OF THE STUDY: This prospective study with minimal 3-year follow-up was performed to compare fusion rates, course of fusion, collapse incidence and occurrence of subsidence in one- and two-level instrumented anterior cervical fusions (ACDF) and thus to proof the hypothesis that use of internal fixation decreases the risk of non-union in bi-segmental ACDFs to the same level that can be expected in mono-segmental procedure. MATERIAL: In 79 consecutive patients operated upon by the Smith-Robinson technique for degenerative process of cervical spine in one or two levels was applied single instrumentation system in order to ensure ideal condition for solid bone fusion of 113 grafts (45 in one and 68 in two levels). All the patients were invariably followed for a minimum of 3 years. METHODS: Radiological criteria were used for evaluation of intervertebral fusion, graft collapse and its subsidence and results were statistically analyzed using M-L Chi-square test for the comparison of fusion and collapse incidence and further Chi-square test for the analysis of fusion course. All these figures were calculated at the level of significance 0.05 (alpha=0.05). RESULTS: Overall, no significant difference was observed in achieving solid bone fusion 3 years after the surgery in one- and two-level procedures (95.6% vers. 92.6%, p=0.522), neither the bone graft collapse rate was of significant difference (2.2% vers. 7.6%, p=0.208). In single-level group the time to bone fusion was significantly shorter (p<0.001). When pooling the data into autologous and allogenic graft subgroup, there was observed no statistically significant difference in achieving union in autologous subgroup (100% vers. 90.9%, p=0.142); in allogenic subgroup this situation was similar: no significant difference in fusion rate (93.3% vers. 93.5%, p=0.980) was observed. In both auto- and allogenic subgroups monosegmentally implanted grafts fused more readily (p<0.001). There was no case of graft subsidence in any investigated group. DISCUSSION: Our prospective study did not find any statistically significant difference in graft collapse and fusion rate when comparing one- and two-level instrumented ACDFs 3 years after the surgery. Plating system used in our patients brings more stability to operated segments and thus presumably prevents micromotions in postoperative period. Micromovements seems to be the major risk factor for non-union in non-instrumented multilevel cervical fusion. Other risk factor that should be considered in non-instrumented procedure is increase in compressive forces that are also partially eliminated by the semirigid internal fixation. Significantly delayed time to union observed in two level fusions shows most probably on increased number of surfaces that must be consolidated during the bone-healing process. CONCLUSION: This study demonstrates that internal fixation used in multilevel ACDF decreases risk of pseudoarthrosis to the same level that can be expected in monosegmental procedures.

[Transarticular fixation of C1-C2: a multicenter retrospective study]. / Transartikulární fixace C1-C2: multicentrická retrospektivní studie.

PURPOSE OF THE STUDY: Transarticular C1-2 fixation is a surgical alternative in treatment of atlantoaxial instability. Although the method provides very good immediate and long-term stability, it still involves several disadvantages. The group of patients as reported from various institutions are usually very small and hardly comparable. In order to objectively compare the results of the method, we collected the groups of patients treated in four institutions dealing with surgery of the cervical spine in Czech Republic. MATERIAL AND METHODS: During the 9-years period (1993-2001), the transarticular C1/2 fixation was performed in 80 patients (mean age 45.6 years, range 4-85 years). The procedure was indicated for atlantoaxial instability due to rheumatoid arthritis in 32 cases, pseudoarthrosis of the odontoid process in 15 cases, fracture of the odontoid in 8 cases, complex C1-C2 fracture in 7 cases, tumour in 5 cases, C1 fracture in 4 cases, os odontoideum in 3 cases, purulent osteolysis of the odontoid in 3 cases and instability due to tuberculosis in one case, respectively. Two patients underwent surgery for painful arthrosis of atlantoaxial joints only. Transarticular fusion was combined with posterior interlaminar fixation using autologous graft and wire in most of the cases. Clinical and radiological results were evaluated in the early postoperative period and 3, 6 and 12 months after surgery, respectively. The position of the screws in relation to lateral mass of the atlas was evaluated according to our own criteria as optimal, suboptimal, and misplaced. Long-term postoperative stability and bone fusion were also followed. The follow-up ranged from 3 to 99 months (mean 29.1 months). There were 72 patients available for long-term follow-up (i.e. more then 6 months). RESULTS: We inserted 150 screws; two screws were used in 72 patients, one screw in 6 patients while in two patients, the surgery had to be aborted without screwing. Optimal placement was achieved in 103 cases (68.7%), suboptimal because of too medial or lateral placement of the screws in 26 cases (17.3%), suboptimal due to a short screw in 9 case (6%) and a long screw in 8 cases (5.3%). Four screws (2.7%) were found misplaced (i.e. out of the lateral masses). Fusion was confirmed in 51 cases out of 72 operated on (70.8%) at 6-months follow-up, and in 55 cases out of 63 available for follow-up (87.3%) at 12 months, respectively. Segmental stability was achieved in all patients, even in cases with incomplete fusion as seen on radiograph. Furthermore, six screws in four patients were discovered to be broken, nevertheless without any clinical consequences. There were 4 cases of peroperative injury to th vertebral artery (i.e. 5% of patients, 2.7% of screws), one case of dural tear and one case of excessive blood loss from epidural venous plexus. These complications, however, did not cause any significant clinical consequences, either. Other postoperative complications included wound dehiscence in 3 cases, 2 cases of hardware failure due to wrong indication for surgery and 2 cases of persistent neck pain. DISCUSSION: Transarticular C1/2 fixation is known to be universal and stable technique suitable for the treatment of atlantoaxial instability. According to biomechanical studies, this method provides the best stability mainly in rotation and lateral flexion (inclination) when compared to other described methods of atlantoaxial fixation. The fusion rate is reported to vary between 90 to 100% if the posterior interlaminar fusion using bone graft and wire is simultaneously performed. The rare incidence of pseudarthrosis is usually considered to be related to a poor surgical technique as even only one screw should provide bone fusion if properly placed. Using strict evaluation criteria, the fusion rate in our sample of patients was 87.3% at 12 months, or, 92.1% if also controversial radiographs were included. The injury to the vertebral artery is the most serious complication of the method; its incidence in our group (5% of patients) is comparable to data from literature. We believe that most of these events happened because of individual anatomical variations of axis and vertebral artery were not adequately respected. CONCLUSION: Transarticular technique of instrumental atlantoaxial fusion is an effective method with multiple application in treatment of craniocervical and upper cervical spine instability. The gain of immediate stability with acceptable risk of possible complications is the major advantage of this procedure. The results of our multicentric retrospective study confirm the expected high fusion rate and are comparable to previously published reports.

[Surgical treatment of dislocated transverse fractures of the sacrum]. / Operacní lécení dislokovaných prícných zlomenin sakra.

PURPOSE OF THE STUDY: Transverse fractures of sacrum are quite rare. Only about 70 cases have been reported in the relevant literature. Low frequency and rather difficult fracture imaging lead to therapeutical uncertainty and are a cause of a delay of urgent surgery. MATERIAL AND METHODS: A group of three male patients aged 17.43 and 31 years was studied. Two patients sustained the injury at a paragliding accident, one by fall from height. One patient underwent only a simple spinal canal decompression 24 days after the injury. The second patient underwent surgery on the fourth day and in the third patient the procedure was carried out sixteen hours after the injury. Procedure on the second and third patient included decompression of neural structures, fracture stabilization as well as spinal-pelvic fixation using an internal fixation. RESULTS: The delayed simple spinal canal decompression didn't improve patient's condition. On the other hand, surgeries performed urgently in the other two patients provided a considerable improvement of the neural deficit. DISCUSSION: Transverse fractures of the upper part of sacrum without any concomitant pelvic fracture are rare and rather difficult to diagnose. Clinical symptoms are inconclusive. However, low back pain, numbness in lower extremities and in the genital, anal region anesthesia should induce the suspicion of this type of trauma even in cases of normal AP and lateral lumbar spine X-rays. In addition to neurological investigation, a lateral x-ray of sacrum and CT and NMR imaging are essential. Conservative treatment, even if complemented with halo-femoral traction does not provide satisfactory results. Also the simple spinal canal decompression gives no contribution to the patient's recovery. Authors suggest a staged surgical procedure providing decompression of neural structures, reduction and stable fixation of the fracture (using screws and plates) and spinal-pelvic stabilization (using the internal spine fixator). Urgent and comprehensive treatment of this type of injury facilitates patient's early mobilization, enables his early discharge and improves neurological recovery. CONCLUSION: Severely displaced fractures of sacrum associated with a neural deficit require the same urgent and comprehensive treatment as vertebral fractures succeeded by a spinal cord injury. Due to low incidence of such injuries patients should be treated at highly specialized centers experienced with this type of surgery.

[Traumatic spondylolisthesis of L5-S1]. / Traumatická spondylolistéza L5-S1.

Pure traumatic bilateral lumbosacral dislocation is a rare injury with just eight cases reported in the literature. This condition occurred also in 36-year-old man, who was struck into the lower back by a falling tree, during a woodcutting, at the moment when he was kneeling and his spine was flexed. Neurological examination showed no signs of spinal nerves injury. X-ray examination of the lumbosacral spine revealed the presence of a 40% anterior dislocation of L5 over S1 with locked facets and multiple fractures of transverse processes. Computer tomography confirmed these findings and also revealed massive medial L5-S1 disc herniation. Surgery performed 9 days after the injury consisted of L5 laminectomy, L5-S1 discectomy and segmental reduction and stabilization with transpedicular screws. Posterior lumbar interbody fusion was carried out using titanium PLIF-blocks. The patient healed without complications. At a 24-month follow-up he was without any subjective complaints, neurologically asymptomatic and without restriction of mobility in the lumbosacral spine. He was able to resume his previous work. This rare case is discussed in a view of the relevant literature, biomechanics of trauma and the appropriate therapy with an emphasis on open reduction and internal fixation techniques.

[Primary osteosynthesis of the odontoid process: a multicenter study]. / Prímá osteosyntéza dentu--multicentrická studie.

PURPOSE OF THE STUDY: Direct osteosynthesis is a method of choice for the treatment of odontoid process fractures. It is based on insertion, from the anterior approach, of one or two screws from the C2 body into the apex of the odontoid across the fracture line. The tensile action of screws results in compression of fragments and stabilization of the fracture. The aim of the study was to evaluate a group of patients treated by this method and to compare our results with those reported in the foreign literature. MATERIAL: A total of 99 patients were treated by direct osteosynthesis of the odontoid in the departments involved in the study between 1994 and 2001. METHODS: Patients indicated for this surgery were those with fractures of type II according to Anderson and D'Alonzo and those with type III fractures but only when the fracture line went across the articulation surfaces of C1-C2, when closed reduction was not possible or the patients were not indicated for halo fixation. Direct osteosynthesis was not applied to fractures with comminution at the base of the odontoid, irreducible fractures, odontoid fractures combined with dislocated fractures of the atlas or pathological fractures. Severe kyphosis of the cervical spine or a large thoracic cage was also regarded as a contraindication. RESULTS: All the 99 patients were followed up from 3 up to 102 months, with an average of 28.5 months; only in seven patients, the follow-up period was shorter than 6 months. The most frequent subjective complaint was a painful operation wound. This usually resolved within two weeks of surgery. Except for four patients, alle were satisfied with the outcome. Type II fractures were diagnosed in 84 and type III fractures in 15 cases. A total of 174 screws were inserted into the odontoid processes of 99 patients. A single screw was used in 25 and two screws in 73 patients. In one case, three screws had to be inserted. Screw lenght ranged from 36 to 44 mm, diameter was 40.9 mm. Three months after surgery, X-ray examination, both in flexion and extension, did not reveal any instability in any of the patients. No morphological change in the C2-C3 intervertebral space was observed Of 92 (92.9%) paitents under longterm follow-up, 84 (91.3%) showed complete healing of the fracture, three died and five patients eventually developed pseudoarthrosis, which was due to a broken screw in three of them. This condition was treated by dorsal fixation of C1-C2 according to Magerl or by one of the dorsal cerclage techniques. The group was free of any perioperative complications related to the anterior approach or injury to nerve structures by screws. DISCUSSION: The most frequent subjective complaint was a painful operation wound. Treatment of odontoid fractures varies according to the type of injury, bone quality and also practice at each department. Type II injuries are highly unstable and, because of the small fracture surface, their healing ability is much lower than in type III fractures. Previously, most of the patients with odontoid injuries were treated conservatively by immobilization in a plaster cast or a brace or, later, by a halo device. In the long term, however, they showed a high proportion of pseudoarthroses (10 to 100%). Direct osteosynthesis of the odontoid by screws permits the maintenance of rotation of the C1-C2 mobile segment. We followed the scheme of indications used abroad but did not perform osteosynthesis to correct pseudoarthrosis. The number of osteosyntheses healed (91.3%) was also in agreement with the literature data. Earlier, we used two screws for all types of fractures. Recently, we have preferred insertion of a single screw in type II and III fractures in narrow odontoids. In the later, there is no danger of rotational dislocation during screw insertion; to insert one screw from the centre of the C2 base is easy and speeds up the procedure. However, in displaced type II and type II T fractures, two screws are a necessity. Similarly to other authors, we recorded a slight limitation of cervical spine rotation in patients at long-term follow-up, particularly in elderly subjects with advanced osteochondrosis. No complications leading to deterioration of the patient's state were recorded. CONCLUSIONS: Direct osteosynthesis is a method of choice for most of the type II and indicated cases of type III fractures of the odontoid process of the axis. This surgical procedure facilitates restoration of anatomical conditions of the spine and its immediate stability. Consequently, patients can be readily mobilized and rehabilitated.