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Adjacent segment degeneration is among the most recognized longterm complications of lumbar surgery for degenerative spine pathologies with a relevant impact in spine surgical and clinical practice. It is reported a incidence of clinical adjacent segment disease between 5-30% of patients undergoing spinal fusion. We aimed to evaluate the main clinical and surgical risk factors for developing adjacent segment disease.A systematic review and meta-analysis of the pertinent literature was performed, according to PRISMA and PICO guidelines, focusing on clinical and radiological adjacent segment disease. We exclusively included studies reporting demographic and clinical data, and surgical details published from 30 September 2015 to 30 September 2020. The effect of considered risk factors on the presence of adjacent segment disease was explored with a random-effects model.A total of 15 scientific publications, corresponding to 6253 patients, met the inclusion criteria for the qualitative and quantitative analysis. 720 of the patients developed a clinical and/or radiological adjacent syndrome disease, and 473 have been surgically managed. Ten articles qualified for the comparative geographical analysis. Advanced age and obesity are relevant risk factors for developing lumbar adjacent segment degeneration. Our data also reported a higher prevalence of adjacent segment degeneration in Western populations than in Eastern populations. The interbody fusion has a protective role toward lumbar adjacent segment degeneration.This study highlighted multifactorial issues regarding adjacent segment disease: clinical, anatomical, biomechanical, and radiological features. In view of increasing life expectancy and spinal surgery procedures, extensive multicenter studies will be needed to define the correct management of the adjacent segment disease.

Objective To mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation. Methods A universal spine tester was used to measure the flexibility of six L2-L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3-L4; 2) on three specimens, the unilateral laminotomy was extended to L4-L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3-L4 in the first three specimens and at L4-L5 in the rest); and 4) pedicle screw fixation at the involved levels. Results Unilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases. Conclusion In vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

Background Image-guided navigation systems (IGS) grant excellent clinical and radiological results, minimizing risks correlated with spinal instrumentation. However, there is some concern regarding the real need for IGS and its indications. Objective To analyze the accuracy, technical aspect, and radiation exposure data of the principal IGS based on computed tomography (CT) imaging. Methods The data of all patients treated for spinal instrumentation with the aid of an IGS system from January 2003 to March 2013 were retrospectively analyzed. We defined 2 groups: group I with an IGS system based on a preoperative CT scan; group II relied on an intraoperative CT scan. Screw accuracy was assessed with a postoperative CT scan control. Radiation dosage for patients was defined by using the technical parameters and dose report data. Statistical analysis was performed using the Fisher exact test with a significance of 5% (P value Results Two thousand twenty patients and 11,144 screws were analyzed. Group I had 794 patients (4246 screws); the accuracy was 96.1%. Group II had 1226 patients (6898 screws) treated, with 98.5% accuracy (P = .001). The radiation dose analysis showed better results in group II, with significant reduction of the effective dose to the patient. Conclusion The IGS based on an intraoperative CT scan grants excellent results, eliminating the rate of reoperation for misplaced instrumentations (screws, plate, and cage) or for inadequate bone decompression. However, this technology cannot replace the surgical skills, experience, and knowledge necessary for spine surgery.

OBJECTIVE The O-arm system in spine surgery allows greater accuracy, lower rate of screw misplacement, and reduced surgical time. Some concerns have been postulated regarding the radiation doses to patients and surgeons. To the best of the authors' knowledge, most of the studies in the literature were performed with the use of phantoms. The authors present data regarding radiation exposure of the surgeon and operating room (OR) staff in a consecutive series of patients undergoing spine surgery. METHODS Radiation exposure data were collected in a series of 107 patients who underwent spine surgery using the O-arm system. The doses received by the surgeon and the staff were collected using electronic dosimeters. RESULTS All patients underwent 1–3 scans. The mean radiation dose to the patients was 5.15 mSv (range 1.48–7.64 mSv). The mean dose registered for the scan operator was 0.005 μSv (range 0.00–0.03 μSv) while the other members of the surgical team positioned outside the OR received 0 μSv. CONCLUSIONS The O-arm system exposes patients to a higher radiation dose than standard fluoroscopy. However, considering the clear advantages of this system, this adjunctive dose can be considered acceptable. Moreover, the effective dose to the patient can be reduced using collimation or minimizing the parameters of the O-arm system used in this paper. The exposure to operators is essentially negligible when radioprotective garments and protocols are adopted as recommended by the International Commission on Radiological Protection.

Objectives: The treatment of lumbar stenosis is based on the relief of pressure on the pinched nerve roots by means of surgical decompression, often resulting in a destabilization of the spine which may progress in a spinal deformity. Despite the extent of the decompression has been identified as a [for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2016)

Study Design:A retrospective, clinical, and radiographic study.Objective:To evaluate the clinical and radiologic outcome of patients treated for cervical spondylosis by anterior cervical discectomy and fusion with the plate-cage system (PCB).Summary of Background Data:Cervical spondylosis and its cl

Study design A retrospective clinical and radiological study. Objective To compare the safety and accuracy of pedicle screw insertion using two different computed tomography (CT) data set acquisitions (preoperative and intraoperative) for computer-guidance systems in a series of 100 consecutive patients. Summary of background data Misplacement and pedicle cortical violation occurs in over 20% of screw placements and can result in potential neurovascular complications. Many technological innovations have been described to help reduce this range of error, such as image-guided surgery using fluoroscopy or CT-based image guidance. However, these techniques are not without their drawbacks. The next technological evolution is the use of an intraoperative CT scan, which would allow us to solve some of the critical phases of spinal navigation, such as position-dependent changes, thus granting a higher accuracy of the navigation system. The authors have compared and discussed the results of a preoperative and intraoperative CT data set acquisition mode for spinal navigation. Methods One hundred consecutive patients with a diagnosis of lumbar degenerative spondylolisthesis who underwent a surgical approach of lumbar pedicle screw fixation using a CT-based computer-guidance system were evaluated. The population was divided into two groups: in group I, a preoperative CT scan was used for the navigation system; whereas in group II, an intraoperative CT scan acquired during surgery was used. Epidemiological and surgical data of the patients in the two groups were then analyzed and compared. The Pearson χ test was used for comparisons between groups (significance level 0.05). The evaluation and classification of the screw positioning was performed on the basis of a control CT scan according to the classification proposed by Laine. Results Out of 504 screws, 471 were correctly inserted into the pedicles (93.5%): the accuracy of group I was of 91.8%, whereas in group II it was 95.2% (no statistical significance). The overall rate of perforation was 6.5% (33 screws): 21 in group I and 12 in group II. Twenty-eight screws had a perforation of the pedicle less than 2 mm (Grade I), three comprised from 2 to 4 (Grade II), and only two more than 4 mm and less than 6 mm (Grade III). Out of 33 misplaced screws only one was replaced (graded as III in group II). Surgical time was shorter for group II, with a statistically significant difference. This result is mainly because of the automatic recognition and merging of the intraoperative images with the surgical anatomy that avoided the phase of registration with a paired-point technique. Conclusion The results of this study suggest that the CT-based computer-assisted surgical navigation systems are precise, granting an elevated accuracy in pedicle screw positioning.

OBJETIVO: estudo prospectivo para avaliar a utilizacao da cifoplastia e vertebroplastia como tecnicas complementares para o tratamento das fraturas osteoporoticas tipo compressao. METODOS: apos um mes de tratamento conservador, os pacientes com fratura osteoporotica do tipo compressao e com dor intratavel, foram submetidos a cifoplastia ou vertebroplastia de acordo com algoritmo que considera o tempo da fratura e a quantidade do colapso do corpo vertebral. Biopsia ossea foi obtida no intra-operatorio para excluir os pacientes com tumor ou osteomalacia. RESULTADOS: cento e trinta e quatro pacientes foram incluidos de acordo com os criterios do estudo. A media de idade foi 67,7 anos. O seguimento medio foi 33 meses. Dez pacientes nao foram seguidos e 154 atingiram um seguimento minimo de dois; 118 pacientes (69,5%) foram submetidos a vertebroplastia e 36 (30,5%) a cifoplastia. Ocorreram complicacoes em cinco pacientse tratados por verebroplastia, sendo que um paciente apresentou neuropatia intercostal transitoria e quatro pacientes fratura por compressao, tendo ocorrido na vertebra adjacente em dois pacientes. Nao foi observada diferenca nos escores da avaliacao da dor e do questionario de Oswestry. CONCLUSAO: apos um seguimento medio de tres anos foram observados resultados satisfatorios com a utilizacao da vertebroplastia ou cifoplastia para o tratamento das fraturas osteoporoticas por compressao. Ambas as tecnicas mostraram bons resultados, de acordo com a sua indicacao especifica.

Object Surgical decompression is the recommended treatment in patients with moderate to severe degenerative lumbar spinal stenosis (DLSS) in whom symptoms do not respond to conservative therapy. Multilevel disease, poor patient health, and advanced age are generally considered predictors of a poor outcome after surgery, essentially because of a surgical technique that has always been considered invasive and prone to causing postoperative instability. The authors present a minimally invasive surgical technique performed using a unilateral approach for lumbar decompression. Methods A retrospective study was conducted of data obtained in a consecutive series of 473 patients treated with unilateral microdecompression for DLSS over a 5-year period (2000–2004). Clinical outcome was measured using the Prolo Economic and Functional Scale and the visual analog scale (VAS). Radiological follow-up included dynamic x-ray films of the lumbar spine and, in some cases, computed tomography scans. Results Follow-up was completed in 374 (79.1%) of 473 patients—183 men and 191 women. A total of 520 levels were decompressed: 285 patients (76.2%) presented with single-level stenosis, 86 (22.9%) with two-level stenosis, and three (0.9%) with three-level stenosis. Three hundred twenty-nine patients (87.9%) experienced a clinical benefit, which was defined as neurological improvement in VAS and Prolo Scale scores. Only three patients (0.8%) reported suffering segmental instability at a treated level, but none required surgical stabilization, and all were successfully treated conservatively. Conclusions Evaluation of the results indicates that unilateral microdecompression of the lumbar spine offers a significant improvement for patients with DLSS, with a lower rate of complications.

Background Image-guided surgery techniques in spinal surgery are usually based upon fluoroscopy or computed tomography (CT) scan, which allow for a real-time navigation of bony structures, though not of neural structures and soft tissue remains. Objective To verify the effectiveness and efficacy of a novel technique of imaging merging between preoperative magnetic resonance imaging (MRI) and intraoperative CT scan during removal of intramedullary lesions. Methods Ten consecutive patients were treated for intramedullary lesions using a navigation system aid. Preoperative contrast-enhanced MRI was merged in the navigation software, with an intraoperative CT acquisition, performed using the O-arm TM system (Medtronic Sofamor Danek, Minneapolis, Minnesota). Dosimetric and timing data were also acquired for each patient. Results The fusion process was achieved in all cases and was uneventful. The merged imaging information was useful in all cases for defining the exact area of laminectomy, dural opening, and the eventual extension of cordotomy, without requiring exposition corrections. The radiation dose for the patients was 0.78 mSv. Using the authors' protocol, it was possible to merge a preoperative MRI with navigation based on intraoperative CT scanning in all cases. Information gained with this technique was useful during the different surgical steps. However, there were some drawbacks, such as the merging process, which still remains partially manual. Conclusion In this initial experience, MRI and CT merging and its feasibility were tested, and we appreciated its safety, precision, and ease.

Background context In spinal surgery, newly developed technology seems to play a key role, especially with the use of computer-assisted image-guided navigation, giving excellent results. However, these tools are expensive and may not be affordable for many facilities. Purpose To compare the cost-effectiveness of preoperative versus intraoperative CT (computed tomography) guidance in spinal surgery. Study design A retrospective economic study. Methods A cost-effectiveness study was performed analyzing the overall costs of a population of patients operated on for lumbar degenerative spondylolisthesis using an image-guided system (IGS) based on a CT scan. The population was divided into two groups according to the type of CT data set acquisition adopted: Group I (IGS based on a preoperative spiral CT scan), Group II (IGS based on an intraoperative CT scan—O-Arm system). The costs associated with each procedure were assessed through a process analysis, where clinical procedures were broken down into single phases and the related costs from each phase were evaluated. No benefits in any form have been or will be received from commercial parties directly or indirectly related to the subject of this article. Results Four hundred ninety-nine patients met the criteria for this study. In total, 2,542 screws were inserted with IGS. Baseline data were similar for the two groups, as were hospitalization and complications. The surgical time was 119±43 minutes in Group I and 92±31 minutes in Group II. The full cost of the two procedures was analyzed: the mean cost, using the O-Arm system (Group II), was found to be €255.83 (3.80%) less than the cost of Group I. Moreover, the O-Arm system was also used in other surgical procedures as an intraoperative control, thus reducing the final costs of radiologic examinations (a reduction of around 550 CT scans/year). Conclusions In conclusion, the authors of the study are of the opinion that the surgical procedure of pedicle screw fixation, using a CT-based computer-guidance system with support of the O-Arm system, allows a shortening of procedure time that might improve the clinical result. However, the present study failed to determine a clear cost-effectiveness with respect to other CT-based IGS.

Pedicle screws with polymethyl methacrylate (PMMA) cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques remains unknown. This study aimed to determine the difference in pullout strength between different cement augmentation techniques. Uniform synthetic bones simulating severe osteoporosis were used to provide a platform for each augmentation technique. In all cases a polyaxial screw and acrylic cement (PMMA) at medium viscosity were used. Five groups were analyzed: I) only screw without PMMA (control group); II) retrograde cement pre-filling of the tapped area; III) cannulated and fenestrate screw with cement injection through perforation; IV) injection using a standard trocar of PMMA (vertebroplasty) and retrograde pre-filling of the tapped area; V) injection through a fenestrated trocar and retrograde pre-filling of the tapped area. Standard X-rays were taken in order to visualize cement distribution in each group. Pedicle screws at full insertion were then tested for axial pullout failure using a mechanical testing machine. A total of 30 screws were tested. The results of pullout analysis revealed better results of all groups with respect to the control group. In particular the statistical analysis showed a difference of Group V (p = 0.001) with respect to all other groups. These results confirm that the cement augmentation grants better results in pullout axial forces. Moreover they suggest better load resistance to axial forces when the distribution of the PMMA is along all the screw combining fenestration and pre-filling augmentation technique.

La ricerca assume rilevanza clinica nella valutazione di diversi parametri che hanno dato conferma dell’esito della terapia. L’applicazione del CCRT ha permesso l’osservazione dei principali nuclei conflittuali del sistema-famiglia, considerato attraverso l’analisi delle dinamiche relazionali. La valutazione dell’Indice di Positività e del Cambiamento Terapeutico concorda con le considerazioni cliniche dell’équipe terapeutica relative all’esito negativo della psicoterapia. Tra gli obiettivi della ricerca abbiamo considerato la possibilità di effettuare una diagnosi familiare attraverso i parametri di ricerca previsti dal metodo del CCRT-LU. La ricerca condotta ha confermato anche questo obiettivo: è possibile effettuare una psicodiagnosi familiare utilizzando il CCRT.

To evaluate the clinical and radiological outcomes of elderly (75 years old) patients who underwent spinal instrumented fusion surgery.Patients underwent lumbar pedicle screw fixation and fusion for degenerative spondylolisthesis. Clinical and radiological outcomes were assessed.53 patients were studied. Pre-operative VAS was 7.8, ODI was 47.6 %. 254 screws were placed (36 single level; 13 double levels and 4 cases three-levels). No mortality occurred. At 18 months follow-up VAS was 4.1, ODI was 21.8 %. A stable fusion was observed in 41 patients (78.8 %); in four cases there was minimal sign of instability and seven patients underwent a second surgery due to screw mobilization.Spinal fixation and fusion in patients older than 75 years old grants good results in terms of quality of life but the rate of morbidity is higher than standard spine surgery. Rate of fusion especially is still a critical point.

BACKGROUND CONTEXT: There is no universal consensus regarding the biomechanical aspects and relevance on the primary stability of misplaced pedicle screws. PURPOSE: The study is aimed to the determination of the correlation between axial pullout forces of pedicle screws with the possible screw misplacement, including mild and severe cortical violations. METHODS: Eighty-eight monoaxial pedicle screws were implanted into 44 porcine lumbar vertebral bodies, paying attention on trying to obtain a wide range of placement accuracy. After screw implantation, all specimens underwent a spiral computed tomography scan, and the screw placements were graded following the scales of Laine et al. and Abul Kasim et al. Axial pullout tests were then performed on a servohydraulic material testing system. RESULTS: Decreasing pullout forces were determined for screws implanted with increasing cortical violation. A smaller influence of cortical violations in the medial direction with respect to the lateral direction was observed. Screws implanted with a large cortical violation and misplacement in the craniocaudal direction were found to be significantly less stable than screws having comparable cortical violation but in a centered sagittal position. CONCLUSIONS: These results provide adjunctive criteria to evaluate more accurately the fate of a spine instrumentation. Particular care should be placed in the screw evaluation regarding the craniocaudal positioning and alignment. 2013 Elsevier Inc. All rights reserved.

The purpose of this study was to evaluate the efficacy of intra-operative computerized tomography (CT) scanning in the analysis of bone removal accuracy during anterior cervical corpectomy, in order to allow any necessary immediate correction in the event of inadequate bone removal.From September 2009 to December 2010 we performed an intra-operative (CT) scan using the O-Arm(™) Image system to assess the rate of central and lateral decompression in all patients treated for cervical spondylotic myelopathy by anterior cervical corpectomy and fusion.Out of a population of 187 patients admitted to our department, with a diagnosis of myelopathy due to spondylotic degenerative cervical stenosis, 15 patients underwent a surgical treatment with anterior cervical corpectomy and fusion. There were nine males (60%) and six females (40%); the mean age was 52.4 years, ranging from 41 to 57 years. The pre-operative radiologic investigations (MRI and CT scans) revealed in the nine patients (60%) the extent of the compression to one vertebral body (C4 one case, C5 four cases, C6 four cases), while in the six cases (40%) the compression regarded two vertebral body (C3 and C4 one case, C4 and C5 two cases, C5 and C6 three cases). During surgery, when the decompression was judged completely, a CT scan was performed: in 11 cases (73.3%) the decompression was considered adequate, while in four cases (26.7%) it was deemed insufficient and the surgical strategy was changed in order to optimize the bone removal. In these cases an additional scan was taken to prove the efficacy of decompression, achieved in all patients.Intra-operative CT scan performed during cervical corpectomy is a really useful tool in helping to ensure complete bone removal and the adequacy of surgery. The O-arm(™) Image system grants optimal image quality, allowing correctly assessing the rate of decompression and, in any case of doubt, allows an intra-operative evaluation of the final correct positioning of the graft.

Chronic lumbar pain due to degenerative disc disease affects a large number of people, including those of fully active age. The usual self-repair system observed in nature is a spontaneous attempt at arthrodesis, which in most cases leads to pseudoarthrosis. In recent years, many possible surgical fusion techniques have been introduced; PLIF is one of these. Because of the growing interest in minimally invasive surgery and the unsatisfactory results reported in the literature (mainly due to the high incidence of morbidity and complications), a new titanium lumbar interbody cage (I-FLY) has been developed to achieve solid bone fusion by means of a stand-alone posterior device. The head of the cage is blunt and tapered so that it can be used as a blunt spreader, and the core is small, which facilitates self-positioning. From 2003 to 2007, 119 patients were treated for chronic lumbar discopathy (Modic grade III and Pfirrmann grade V) with I-FLY cages used as stand-alone devices. All patients were clinically evaluated preoperatively and after 1 and 2 years by means of a neurological examination, visual analogue score (VAS) and Prolo Economic and Functional Scale. Radiological results were evaluated by polyaxial computed tomography (CT) scan and flexion–extension radiography. Fusion was defined as the absence of segmental instability on flexion–extension radiography and Bridwell grade I or II on CT scan. Patients were considered clinical “responders” if VAS evaluation showed any improvement over baseline values and a Prolo value >7 was recorded. At the last follow-up examination, clinical success was deemed to have been achieved in 90.5% of patients; the rate of bone fusion was 99.1%, as evaluated by flexion–extension radiography, and 92.2%, as evaluated by CT scan. Morbidity (nerve root injury, dural lesions) and complications (subsidence and pseudoarthrosis) were minimal. PLIF by means of the stand-alone I-FLY cage can be regarded as a possible surgical treatment for chronic low-back pain due to high-degree DDD. This technique is not demanding and can be considered safe and effective, as shown by the excellent clinical and radiological success rates.