Maximum Safety Limits of Laminectomy of the C1 Vertebra for Chiari Malformation Surgery: A Finite Element Analysis.

Background: The treatment of Chiari malformations generally consists of posterior fossa decompression. C1 laminectomy is required in selected cases. However, cases of iatrogenic anterior arch fractures at C1 without high-energy trauma have been reported. Developing theoretical models of atlas C1 bones that have undergone a laminectomy can help researchers identify the regions where fractures may occur as a result of sudden loads. Methods: In this study, we created a detailed three-dimensional solid finite element model of the human atlas bone (C1) using geometric data. The loadings of the laminectomy dimension were evaluated on the basis of three groups. Group I comprised atlas bones that had not undergone a laminectomy. For Group II, the lateral border of the laminectomy was determined as the projection of the lateral mass medial border on the lamina. For Group III, the bilateral sulcus arteriosus was determined as the border for the lateral border of the laminectomy. The analysis results, which are in good agreement with those of previous reports, showed high concentrations of localized stress in the anterior and posterior arches of the atlas bone. Results: The analysis results showed that the stress increased in the laminectomy models. The maximum stress observed was consistent with the clinical observations of fracture sites in previous studies. Conclusion: In the treatment of patients with Chiari malformations, C1 laminectomy is often required. The width of this laminectomy can lead to iatrogenic anterior arch fractures. This is the first study to evaluate C1 laminectomy width using finite element modeling.

Spinal Schwannomas: A Proposal for a New Classification to Aid Surgical Planning.

Background The treatment of spinal schwannomas, which is the most common nerve sheath tumor, is total microsurgical resection. The localization, size and relationship with the surrounding structures of these tumors are crucial in terms of preoperative planning. A new classification method is presented in this study for the surgical planning of spinal schwannoma. Methods All patients who underwent surgery for spinal schwannoma between 2008 and 2021 were reviewed retrospectively, along with radiological images, clinical presentation, surgical approach, and postoperative neurological status. Results A total of 114 patients, 57 male, and 57 females were included in the study. Tumor localizations were cervical in 24 patients, cervicothoracic in one patient, thoracic in 15 patients, thoracolumbar in eight patients, lumbar in 56 patients, lumbosacral in two patients, and sacral in eight patients. All tumors were divided into seven types according to the classification method. Type 1 and Type 2 groups were operated on with a posterior midline approach only, Type 3 tumors were operated on with a posterior midline approach and extraforaminal approach, and Type 4 tumors were operated on with only an extraforaminal approach. While the extraforaminal approach was sufficient in type 5 patients, partial facetectomy was required in 2 patients. Combined surgery including hemilaminectomy and extraforaminal approach was performed in the type 6 group. A posterior midline approach with partial sacrectomy/corpectomy was performed in Type 7 group. Conclusion Effective treatment of spinal schwannoma depends on preoperative planning, which includes correctly classifying tumors. In this study, we present a categorization scheme that covers bone erosion and tumor volume for all spinal localizations.

Sella Volume and Posterior Fossa Morphometric Measurements in Chiari Type 1.

AIM: To retrospectively evaluate the relationships between morphometric measurements in craniovertebral junction, and the possible genetic basis of the disease in Chiari 1 malformation patients undergoing surgical treatment. MATERIAL AND METHODS: We included patients who underwent surgical treatment for Chiari 1 malformation with unknown etiology between 2013-2018 in the Neuosurgery Clinic of Eskisehir Osmangazi University. Morphometric and volumetric measurements of the posterior fossa from cranial and cervical radiological imagings of patients with Chiari 1 malformation were performed by a single experienced observer. The results were independently reviewed by two experienced observers who supervised the process and verified the calculations. RESULTS: It was observed that basal angle was greater in the group of patients with Chiari 1 malformation (125.29° ± 9.522° Vs. 112.33° ± 9.09°), and a significant difference was observed (p=0.000). In patient group, it was also found that the basion-dens distance (3.51 mm ± 1.695mm Vs. 5.27 ± 1.695 mm) (p=0.000), and cerebellar hemispher height were shorter (58.47 ± 5.143 mm Vs. 52.05 ± 5,008 mm) (p=0.000). Tentorium angle was greater in the patient group (97.95° ± 11.321° vs. 87.79° ± 9.891°) (p=0.034). In patient group, dens height was found to be longer (13.9 ± 2.46 mm vs. 14.79 ± 1.631mm) (p=0.041). Sella volume was found to be smaller (41.4 mm3 Vs. 53.3 mm3) in the patient group compared to the control group (p=0.034), and foramen magnum plane was larger (64.6° vs. 31.1°) (p=0.000). CONCLUSION: It is concluded that many parameters including BA, FMP, BDD, CHH, TA, DH, and cellar volume are abnormal, suggesting the need for focussing to the hormonal metabolism - related synchondral changes.

Short-Term Results of Simpson Grade 2 Resection in Spinal Meningiomas.

BACKGROUND: Spinal meningiomas are benign and slow-growing intradural tumors. Surgery is the choice of treatment. In this retrospective study, results of minimally invasive Simpson grade 2 resection and its impact on recurrence in 44 spinal meningiomas are reviewed. METHODS: Clinical data of 44 cases who underwent surgery for spinal meningiomas between 2010 and 2020 have been reviewed retrospectively. Demographics, preoperative and postoperative clinical states, pathologic type, location of the meningioma relative to the spinal cord, resection amount of the tumor according to Simpson's grading scale, postoperative complications, recurrence rate, and correlation between preoperative and intraoperative data and recurrence were analyzed. RESULTS: The tumor was located in the thoracic spine in 31 cases, in the cervical spine in 12 cases, and in the lumbar spine in one case. Dural attachment of tumor was ventral to the spinal cord in 15 cases, lateral to the spinal cord in 15 cases, and posterior to the spinal cord in 14 cases. All cases underwent microsurgical Simpson grade 2 resection. Two cases were recurrent and reoperated. Recurrences were observed in cases younger than 18 years old, in cervical spines and in cases with long dural tails. CONCLUSIONS: Simpson grade 2 resection is safe and effective in spinal meningiomas. Patients younger than 18 year old, and those with cervical location and long dural tail may be under risk of recurrence after Simpson grade 2 resection.

Approach to Primary Vertebral Tumors in the Light of the 2020 Updated World Health Organization Classification of Bone Tumors.

AIM: To define a new approach for primary vertebral tumors by discussing them in the light of 2020 World Health Organization (WHO) classification of bone tumors. MATERIAL AND METHODS: In this study, we have discussed primary vertebral tumors in light of the 2020 Updated WHO Classification of Soft Tissue and Bone Tumors. RESULTS: Chondroblastoma and chondromyxoid fibroma has been classified in the benign category, while synovial chondromatosis has been moved from the benign category to the intermediate category. In the updated classification, grade I chondrosarcoma has been classified in the malignant category with grade II?III chondrosarcomas. Minor amendments have been made for osteosarcoma subtypes. Neoplasms of undetermined origin, such as aneurysmal cysts, simple bone cysts, fibrosis dysplasia, and osteofibrous dysplasia, have been classified as neoplastic lesions. Chordomas have been classified into ?not otherwise stated,? poorly differentiated chordomas, and dedifferentiated chordomas. Ewing?s sarcomas have been classified in a separate section for undifferentiated, small, round cell sarcomas of the bone and soft tissue. In this section, three distinct subsets different from Ewing?s sarcoma have been discussed. CIC-rearranged sarcoma, BCOR-rearranged sarcoma, and round cell sarcomas with EWSR1 gene fusion with non-ETS family members. CONCLUSION: In this study, we have reviewed the new classifications and discussed their effect on decision making in spinal oncologic surgery.

Prominent Neurosurgery Books: How they Defined the Era of Modern Neurosurgery in the 19th Century.

OBJECTIVE: The aim of this article is to introduce the 19th century neurosurgery books to reveal their contributions to modern neurosurgery. Methods In this study, 29 books were accessed, and reviewed, and the resources from the late 18th century and early 20th century were included. However, neurology or general surgery books that included neurosurgical subjects or chapter were excluded unless there were revolutionary ideas in their relevant chapters. RESULTS: The books of this period observed to have some common differences from the books that were written in the previous century. Parallel to the concept of cerebral localization, which started to develop in this period, neurosurgery evolved from skull surgery to brain surgery. CONCLUSIONS: Due to the advancements in patient care, anesthesia and sterile techniques, surgical medical branches showed rapid development in the 1800s. During this period, cerebral localization concept changed the comprehension and approach in neurosurgery and opened the gate of a new era in the field of neurological surgery unlike other branches and helped to establish modern neurosurgery. 19th century surgeons became able to operate on more complex cases with more advanced techniques. Knowledge of published pioneer papers and books help understanding of emergence of neurological surgery as a separate discipline.

Comparison of clinical and radiological results of dynamic and rigid instrumentation in degenerative lumbar spinal stenosis.

Objective: Lumbar spinal stenosis is defined as a clinical syndrome characterized by neurogenic claudication or radicular pain due to the narrowing of the spinal canal or neural foramen and the compression of its neural elements. Surgical treatment is applied to decompress the neural structures. In some cases, transpedicular instrumentation and fusion may also be applied. In this study, we aimed to investigate and compare the preoperative and postoperative, clinical and radiological aspects of patients with lumbar spinal stenosis who underwent lumbar instrumentation using a polyetheretherketone (PEEK) rod or a titanium rod. Materials and Methods: In this study, the files of 293 patients who underwent posterior lumbar transpedicular stabilization between January 2015 and February 2018 in the Neurosurgery Clinic of Ümraniye Training and Research Hospital were reviewed retrospectively. Patients who did not meet the study criteria were excluded, and 127 patients who met the criteria and underwent posterior lumbar transpedicular stabilization due to lumbar spinal stenosis and/or lumbar degenerative disc disease were retrospectively reviewed. The patients were divided into two groups, dynamic and rigid, according to the rod types used. The two groups were compared using various postoperative clinical and radiological parameters. Results: The demographic data, surgical data, Visual Analog Scale-Oswestry Disability Index (VAS-ODI) data, and radiological data of both groups were carefully examined. There were 63 patients in the rigid group and 64 patients in the dynamic group. The age range in both groups was from 30 to 78 years, with a mean age of 56.44 years; 99 of the cases were female and 28 were male. The analysis of the participants' demographic data showed no significant differences between the two groups. Compared with the preoperative data, the postoperative evaluations revealed a significant decrease in VAS and ODI, but no significant difference was observed between the two groups. There was no difference between the two groups in terms of duration of surgery, follow-up time, operating distances, hospitalization duration, pseudoarthrosis, or fusion. Regarding the total and segmental range of motion, the affection was less in the dynamic group, which allowed for more movement. While there was no difference in disc height index between the two preoperative groups, it was observed that it was better maintained in the rigid group in the postoperative long term. Regarding foraminal height (FH), there was no difference between the two groups in the preoperative and early postoperative periods, but in the long term, FH was better maintained in the dynamic group. The long-term follow-ups revealed that adjacent segment disease (ASD) had developed in 19 patients in the rigid group, whereas ASD developed in only nine patients in the dynamic group. Based on these results, the probability of developing significant ASD in the rigid group was higher. Conclusion: Previous experience with PEEK rod systems has demonstrated physiological spine movement, increased fusion rates, minimal complications, reduction in adjacent segment degeneration, and biomechanical compatibility. Although further long-term studies are needed and the cost of PEEK systems is likely to be a barrier, the results of the present study support the use of PEEK rods and other dynamic systems in spinal surgery.

Surgical Treatment of Spinal Arachnoid Cysts: Cyst Excision or Fenestration?

AIM: Arachnoid cysts in the spinal canal account for 1%-3% of all spinal canal lesions. There is no consensus on surgical treatment yet. Dural defect repair is crucial in surgical treatment patients with an extradural component. Fenestration or total resection of the spinal arachnoid cyst is among the preferred methods. This study aimed to examine a series of surgically treated spinal arachnoid cysts in light of the literature. MATERIAL AND METHODS: This was a retrospective study of patients treated in the Istanbul Umraniye Training and Research Hospital Neurosurgery Clinic. A total of 18 patients with spinal arachnoid cysts underwent surgical treatment between 2012 and 2021. All patients were assessed before and after surgery for muscle strength, pain, sensory changes, and bowel-bladder symptoms. All patients underwent magnetic resonance imaging and computed tomography for diagnosis and treatment. RESULTS: Among the 18 patients, 8 were men and 10 were women, with a mean age of 43.7 (25-66) years. Congenital conditions were discovered in 15 of the patients, 2 after lumbar drainage and 1 after spinal anesthesia. Intradural extramedullary and intra-extradural cysts were found in 17 patients and 1 patient, respectively. The cyst was smaller than level 3 in 14 patients and greater than level 3 in 4 patients. Cyst excision and cyst fenestration were performed in 11 and 7 patients, respectively. Cyst excision was performed in four of the patients who underwent cyst fenestration because their complaints did not improve. CONCLUSION: Surgery should be considered in patients with symptomatic spinal arachnoid cysts. Fenestration may be a suitable alternative, especially if magnetic resonance imaging reveals no intracystic adhesion or trabeculation. Residual and recurrence rates are high in patients with a history of intradural intervention, adhesions, or trabeculation. When there is trabeculation, the best option is cyst removal.

Results of percutaneous cervical vertebroplasty using an anterolateral approach for cervical spine tumors.

OBJECTIVE: The aim of this study was to report the results of percutaneous vertebroplasty in managing symptomatic osteolytic cervical spine tumors. METHODS: This study comprised a retrospective examination of patients who received percutaneous vertebroplasty between 2008 and 2020 for the treatment of tumor-induced symptomatic cervical vertebra involvement. The study summarized the demographics, vertebral levels, pain control rates, clinical results, and complications of percutaneous vertebroplasty using an anterolateral approach. RESULTS: The study sample consisted of 6 female and 2 male patients aged between 20 and 56 (mean=41.37) years. Tumors were located at C2 in 6 cases, at C3 in 1 case, and at C5 in another. The mean volume of poly (methyl methacrylate) injected was 1.5 mL (range: 1-2 mL). Biopsy results showed the presence of metastasis in 5 cases and plasmacytoma in 3. No postoperative complications or mortality were observed after the procedure. Preoperative mean 7.75 visual analog scale score decreased to 2.62. Pain control was reported to be 66.2%. CONCLUSION: Anterolateral cervical vertebroplasty seems to be a safe, effective, and helpful therapeutic alternative for the treatment of cervical spine tumors. It reduces the risk of infection compared to the transoral method. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

Management of Spinal Lymphomas: Spinal Instability Assessment Using the Spinal Instability Neoplastic Score and a Proposed Treatment Algorithm.

AIM: To propose a treatment algorithm, and to assess spinal instability in patients diagnosed with spinal lymphoma. MATERIAL AND METHODS: Demographics, symptoms, tumor level and location, and presence of spinal instability were reviewed in 22 patients with spinal lymphomas. Each patient's neurological state was reviewed using the American Spinal Injury Association and modified McCormick scale scores, and spinal instability was assessed using the Spinal Instability Neoplastic Score (SINS). RESULTS: Initially, percutaneous biopsy was performed in 16 patients, and open biopsy was performed in 6 patients. Eight of the patients who underwent percutaneous biopsy were followed up with hematological examination alone, as they had no additional complaints. The SINS was used to evaluate the presence of spinal instability, and the type of surgery to be performed was decided accordingly. In the second surgery, decompression and stabilization were performed in 5 of the remaining 8 patients, and only decompression was performed in 3 of them. Neurological improvement was observed in 6 of 7 patients with acute neurological deficit. CONCLUSION: Percutaneous biopsy for tissue diagnosis is the first step in the management of spinal lymphomas. Patients without neurological deficit should be referred for hematological examination. Those with acute neurological deficit require emergency surgery, and those with chronic symptoms must undergo operation for decompression and/or stabilization. This study confirmed the safety of the SINS in the evaluation of spinal instability in spinal lymphoma cases.

Role of Spinal Instability Neoplastic Score in Management of Spinal Plasmacytoma.

OBJECTIVE: The decision to perform surgery in cases of spinal plasmacytoma (SP) is controversial. This study aimed to evaluate the reliability of the Spinal Instability Neoplastic Score (SINS) in evaluation of spinal instability in patients with SP. METHODS: Clinical and radiological characteristics of 10 patients with SP were retrospectively evaluated. Age, sex, preoperative symptoms, duration of symptoms, pain score, American Spinal Injury Association score, and SINS were analyzed. RESULTS: The 10 patients included 6 men and 4 women. Plasmacytoma was located in the sacrum in 1 patient, in the lumbar spine in 2 patients, in the thoracic spine in 6 patients, and in the cervical spine in 1 patient. Biopsy was performed in 2 patients, biopsy and vertebroplasty were performed in 2 patients, and biopsy and acute decompression and stabilization surgery were performed in 6 patients. SINS was <7 in 1 patient, 7-12 in 5 patients, and >12 in 4 patients. Two patients with a low SINS (<13) underwent only biopsy, and 2 patients underwent biopsy and vertebroplasty. Decompression and stabilization surgery was performed in 2 patients with SINS 7-12 and 4 patients with SINS >12. CONCLUSIONS: Decision making regarding augmentation, decompression, and stabilization in patients with SP is controversial. SINS may play a role during the decision-making process. Augmentation can be performed in patients with painful SPs with osteolytic changes with or without fracture (SINS <13). Decompression and stabilization surgery is the first-choice treatment in patients with SINS >12.

Can Posterior Midline Approach Provide Adequate Exposure for All Craniovertebral Junction Tumors?

INTRODUCTION: The surgical treatment of craniovertebral junction (CVJ) lesions remains a difficult process requiring advanced experience. The aim of this study was to present our experience and the clinical results of a posterior and posterolateral approach used for CVJ lesions in our clinic, and to discuss these in light of current literature. METHODS: Clinical, radiologic, and surgical aspects of 30 patients with CVJ tumors were retrospectively evaluated. Age, sex, symptoms, tumor localizations, pre- and postoperative neurologic examinations, performed surgical techniques, postoperative complications, and tumor pathologies were analyzed. The modified McCormick classification was used in the evaluation of the neurologic examination. RESULTS: There were 30 patients (12 men, 18 women; mean age: 41.8 years). Hemilaminectomy was performed in 14 cases, and total laminectomy or laminoplasty in 16 cases; additional suboccipital craniectomy was performed in 6. Postoperative mortality was observed in 1 (3.3%) patient in the early postoperative period following tetraparesis, motor deficit in 2 (6.6%), cerebrospinal fluid leakage in 2 (6.6%), and wound site infection in 1 (3.3%). A tumor rest was detected in 2 patients (6.6%). CONCLUSIONS: A posterior or a posterolateral approach is a safe surgical technique that can provide total tumor resection for CVJ region lesions, including posterior, posterolateral, lateral, and anterolaterally located tumors. Isolated anterior and anterolateral tumors with small lateral extension may require a far lateral or extreme lateral approach combined with other cranial base techniques.

Unusual presentation of immunoglobulin G4-related disease: A case report.

Immunoglobulin G4-related disease (IgG4-RD) is an inflammatory disease characterized by a tumor-like infiltration of IgG4 positive plasma cells and fibrosis in various organs. The exact pathogenesis remains unknown. In this article, we discuss the diagnostic management of IgG4-RD with reference to clinical, serologic, pathological and radiological data on a 17-year-old male patient with lumbar vertebral involvement.

Posterior Wall Defect of Sacrum: An Anatomical Study of Sacral Spina Bifida.

AIM: To investigate the incidence, types, morphological and morphometric properties of spina bifida on dry sacral bones. MATERIAL AND METHODS: 110 dry adult sacrums gathered from the bone collections of the Laboratory of the Anatomy Department of Dokuz Eylul University School of Medicine were examined. The parameters analysed were: 1) results of parameters related to the posterior sacral wall; 2) classification and rate of the closure defects; 3) classification of the top sacral vertebrae according to the shape of its superior surface; 4) presence of sacralisation and lumbalisation among sacrums with dorsal wall defects; 5) vertebral levels of apex of the sacral hiatus; and 6) vertebral levels of closure defects of the sacrums. RESULTS: We determined 22/110 (20%) sacrums demonstrated spina bifida. Of these 22 sacrums, 4 (18.18%) showed complete and 18 (81.82%) showed incomplete spina bifida. We noted the coexistence of spina bifida with sacralisation (6/22 [27.27%]) and lumbalisation (5/22 [22.73%]). The types of defects were described and grouped as ?V? (Type 1), inverse ?V? (Type 2), window (Type 3), foramen (hole) (Type 4), sand watch (Type 5), narrow linear (Type 6), wide linear (Type 7), and bridged (Type 8). The shape of upper surfaces of the sacrums with spina bifida was grouped as: cavity (20/22, 90.9%), hump (1/22, 4.5%), and flat (1/22, 4.5%). CONCLUSION: A precise definition of the anatomical variations of sacrums is essential for surgeons, particularly when operating using endoscopic techniques and for anaesthesiologists applying caudal epidural block.

Pediatric age, posterior fossa meningioma.

Meningiomas are benign, slow-growing tumors originating from arachnoid gap cells. They constitute 15%-20% of all intracranial tumors in adults and 04%-4% in the pediatric age group. Meningiomas in the posterior fossa in the pediatric period do not initially come to mind. In the case presented here, there was a cystic meningioma showing heterogenous contrast and obstructive hydrocephaly was observed associated with 4th ventricle pressure. the tumor was totally removed, then the ventriculo peritoneal shunt was applied.

Bone-to-bone ligament preserving laminoplasty technique for reconstruction of laminae.

INTRODUCTION: Laminoplasty is a method used in spinal intradural tumor surgery to reduce the possibility of iatrogenic deformity. In classic laminoplasty, the interspinous, supraspinous, and ligamentum flavum integrity may be impaired, thereby creating a risk of deformity despite the laminoplasty. The aim of this study was to review the outcomes of bone-to-bone ligament preserving laminoplasty (BLP laminoplasty) technique. MATERIALS AND METHODS: The data of 14 cases who underwent BLP laminoplasty for intradural spinal tumor between 2017 and 2019 were reviewed. Through examination of preoperative and postoperative computed tomography images and flexion-extension lateral X-rays, the fusion and kyphotic changes were evaluated in the laminas. An axial Visual Analog Scale (VAS) was used to evaluate clinical satisfaction. RESULTS: The cases comprised 10 females and 4 males, with a mean age of 39.2 years (range, 16-52 years). The masses were intramedullary in six cases and extramedullary in eight. Lumbar region localization was most frequent. Ependymoma was determined in 8 cases, schwannoma in 4, and meningioma in 2. Laminoplasty was applied at 43 levels (10 thoracic and 33 lumbar). No complications were observed, and fusion was obtained in all the cases at the end of 1 year. No segmental kyphotic changes were determined. In the clinical evaluation, the VAS scores improved from 3.4 ± 2.0 preoperatively to 1.8 ± 2.1 postoperatively. CONCLUSION: BLP laminoplasty is a safe technique which preserves posterior ligamentous integrity. Furthermore, the use of ultrasonic bone scalpel provides a narrower gap between laminae and other bones, preventing dislocation, and allowing for more fusion, and consequently preventing kyphosis.

Lamina Measurements with Computed Tomography for C2 Translaminar Screw Fixation in Pediatric and Adult Cases.

AIM: To measure C2-related morphometric parameters in a Turkish population. MATERIAL AND METHODS: The computed tomography (CT) images of three groups (Group 1: paediatric cases aged 1-6 years, Group 2: age7-16 years, and Group 3: adult cases), who had cervical spine CT were used to measure some morphometric parameters for safe C2 translaminar screw fixation. The measured parameters included thickness, height and length of the C2 lamina on both sides and the C2 lamina-midline angle. RESULTS: C2 lamina thickness at the thinnest point on the right and left sides was found to be 4.4 ± 0.5 mm and 4.6 ± 0.5 mm in Group 1, 5.3 ± 0.8 mm and 5.6 ± 0.8 mm in Group 2, and 6.8 ± 1.4 mm and 7.0±1.5 mm in Group 3, respectively (p > 0.05). The height of the C2 lamina at the thinnest point on the right and left sides was found to be 5.8 ± 0.8 mm, and 5.8 ± 0.7 mm in Group 1,10.4 ± 1.4 mm and 10.6 ± 1.4 mm in Group 2, and 10.6 ± 1.8 mm, and 10.7 ± 1.5 mm in Group 3, respectively (p > 0.05). The mean length of the C2 lamina was found to be 20.6 ± 2.4 mm in Group 1, 31.4 ± 4.1 mm in Group 2, and 36.7 ± 3.3 mm in Group 3 (p < 0.05). There was no significant difference between Group 2 and Group 3 in respect of mean lamina angle (44º vs 45º) but it was lower in Group 1 (35º). CONCLUSION: This study revealed the appropriateness of C2 anatomy for safe C2 translaminar screw fixation.

Illumination of The Relationship between Ureter and Intervertebral Disc by Computed Tomography.

AIM: To show the relationship of lumbar intervertebral discs with the ureters by using computerized tomography (CT). MATERIAL AND METHODS: Eighty patients (male/female: 42/38) with a mean age of 45 years were included in this retrospective study. An imaginary line passing through the tangential to the posterior cortex of the vertebral body was drawn at the intervertebral disc level (line a). Perpendicular to this line were two lines (line b) drawn from the ureters.The lines of the cortex, where ?line a? was cut (point c), were also drawn from the contralateral ureter (line d). The distances between ?lines b and d? were measured. Another line was drawn from both ?c? points to the ipsilateral ureters (line x). The angle between ?lines a and x? was measured (angle x). RESULTS: The right kidney hilus was inferior to the left kidney hilus. A significant negative correlation was observed between line band lumbar level (r=?0.95). The average length of ?line b? at the lower lumber levels was 2.1 cm. Moreover, a positive correlation was found between ?angle x? and lumbar level (p < 0.05). The ?angle x? increased from 38° to 80° with the decrease in lumbar levels. In addition, the ?angle x? was significantly higher in male patients (p < 0.05) than in female patients. No significant correlation was found between ?line d? and lumbar level. CONCLUSION: CT is an illumination modality that could elucidate the relationship between intervertebral disc and ureter preoperatively and could visualize the retroperitoneum.

Spinal Hemangioblastomas and Neuropathic Pain.

BACKGROUND: Spinal hemangioblastomas (SHs) are rare and benign tumors. Primary symptoms include pain, hypoesthesia, and neuropathic pain (NP). Clinical symptoms may be as a result of tumor mass effect, peritumoral effect, syrinx, or venous congestion. No studies have focused on NP in SHs. The objective of this study was to review the rate and causes of NP in patients with SHs. METHODS: The present study comprises a retrospective analysis of 13 patients with spinal hemangioblastomas. For the retrospective analysis of the patients, we analyzed the absence or presence of NP in the pre- and postoperative periods and its relationship with the level, location, and size of the tumor, as well as the size and location of the syrinx. RESULTS: Postoperative NP was detected in 6 out of 13 patients. All 6 patients' tumors were located at the dorsal aspect of the spinal cord. There was a predominance of rostral syrinx location in patients with NP. Tumor size and level and syrinx size and level were not found to affect the occurrence of NP. CONCLUSIONS: The present study shows that NP is observable in both pre- and postoperative periods. Proximity of the tumor to the dorsal root entry zone, and especially the presence of rostral syrinx, are the main factors affecting postoperative NP symptomatology. It is concluded that the combination of these factors and iatrogenic injury of anatomic pathways of NP within the spinal cord are responsible for postoperative NP.

A Novel Perspective for Analyzing Craniocervical Sagittal Balance and Horizontal Gaze.

BACKGROUND: This study aimed to analyze craniocervical sagittal balance parameters in an asymptomatic population revealing the interaction of craniocervical compensation with the horizontal gaze and to identify a new parameter that can be evaluated more easily with the horizontal gaze. METHODS: Lateral radiographs were taken of the 75 asymptomatic volunteers. Two independent observers measured the pelvic, spinal, and cranial parameters, spinocranial angle, and C2-7 sagittal vertical axis (C2-7SVA) distances. The correlations between these parameters and the differences in the created subgroups were analyzed. RESULTS: Correlations were found between the sacral slope and L1-L5 lordosis (r = 0.700), between L1-L5 lordosis and thoracic kyphosis (r = 0.363), between thoracic kyphosis and C2-7 lordosis (r = 0.425), and between C2-7 lordosis and C2 slope (C2S) (r = -0.735). In addition, this chain was extended to include the cranium, showing a strong correlation between the C2S and the cranial slope (CS) (r = -0.827). Strong correlations were observed between the CS and C2S (r = -0.827), C2-C7 lordosis (r = 0.583), C2-7 SVA (r = -0.437). The importance of O-C2 lordosis was significantly increased in the patient cohort with a prominent C2S (≥13) and became the main determinant of the CS (r = 0.667) together with the C2S (r = -0.800). CONCLUSIONS: The factors affecting horizontal gaze are C2S, C2-7 lordosis, O-C2 lordosis, and C2-7 SVA. C2S can be used as an indicator of the horizontal gaze in preoperative surgical planning and postoperative evaluation.