Perimedullary arteriovenous fistulas (PMAVFs) are uncommon vascular malformations, and they rarely occur at the level of the craniovertebral junction (CVJ). The therapeutic management is challenging and can include observation alone, endovascular occlusion, or surgical exclusion, depending on both patient and malformation characteristics. A systematic literature search was conducted using MEDLINE, Scopus, and Google Scholar databases, searching for the following combined MeSH terms: (perimedullary arteriovenous fistula OR dural arteriovenous shunt) AND (craniocervical junction OR craniovertebral junction). We also present an emblematic case of PMAVF at the level of the craniovertebral junction associated to a venous pseudoaneurysm. A total of 31 published studies were identified; 10 were rejected from our review because they did not match our inclusion criteria. Our case was not included in the systematic review. We selected 21 studies for this systematic review with a total of 58 patients, including 20 females (34.5%) and 38 males (65.5%), with a female/male ratio of 1:1.9. Thirty-nine out of 58 patients underwent surgical treatment (67.2%), 15 out of 58 patients were treated with endovascular approach (25.8%), 3 out of 58 patients underwent combined treatment (5.2%), and only 1 patient was managed conservatively (1.7%). An improved outcome was reported in 94.8% of cases (55 out of 58 patients), whereas 3 out of 58 patients (5.2%) were moderately disabled after surgery and endovascular treatment. In literature, hemorrhagic presentation is reported as the most common onset (subarachnoid hemorrhage in 63% and intramedullary hemorrhage in 10%), frequently caused either by venous dilation, due to an ascending drainage pathway into an intracranial vein, or by the higher venous flow rates that can be associated with intracranial drainage. Hiramatsu and Sato stated that arterial feeders from the anterior spinal artery (ASA) and aneurysmal dilations are associated with hemorrhagic presentation. In agreement with the classification by Hiramatsu, we defined the PMAVF of the CVJ as a vascular lesion fed by the radiculomeningeal arteries from the vertebral artery and the spinal pial arteries from the ASA and/or lateral spinal artery. Considering the anatomical characteristics, we referred to our patient as affected by PMAVF, even if it was difficult to precisely localize the arteriovenous shunts because of the complex angioarchitecture of the fine feeding arteries and draining veins, but we presumed that the shunt was located in the point of major difference in vessel size between the feeding arteries and draining veins. PMAVFs of CVJ are rare pathologies of challenging management. The best diagnostic workup and treatment are still controversial: more studies are needed to compare different therapeutic strategies concerning both long-term occlusion rates and outcomes.

Background: Laminoplasty is a method of posterior cervical decompression which indirectly decompresses the spinal column. Unfortunately, many patients undergoing laminoplasty develops postoperative loss of cervical lordosis (LCL) or kyphotic alignment of cervical spine even though they have sufficient preoperative lordosis which results in poor surgical outcome. Objective: We would like to highlight the relationship between various radiological parameters of cervical alignment and postoperative LCL in patients undergoing laminoplasty. Methods: We performed extensive literature search using PubMed, Google Scholar, and Web of Science for relevant articles that report factors affecting cervical alignment following laminoplasty. Results: On reviewing the literature, patients with high T1 slope have more lordotic alignment of cervical spine preoperatively. They also have more chances of LCL following laminoplasty. C2–C7 sagittal vertical axis (SVA) has no role in predicting LCL following laminoplasty though patients with low T1 slope (≤20°) and high C2–C7 SVA (>22 mm) had correction of kyphotic deformity following laminoplasty. C2–C7 lordosis, Neck Tilt, cervical range of motion, and thoracic kyphosis has no predictive value for LCL. Lower value of T1 slope (T1S-CL) and CL/T1S has more incidence of developing LCL following laminoplasty. The role of C2–C3 disc angle has not yet been evaluated in patients undergoing laminoplasty. Dynamic extension reserve determines the contraction reserve of SPMLC and lower dynamic extension reserve is associated with higher chances of LCL following laminoplasty. Conclusions: Cervical lordotic alignment is important in maintaining cervical sagittal balance which ultimately is responsible for global spinal sagittal balance and horizontal gaze. Among various radiological parameters, T1 Slope has been reported to be the most important factor affecting cervical alignment following laminoplasty.

Introduction: This study aimed to identify complication trends of Chiari Malformation Type 1 patients (CM-1) for certain procedures and concomitant diagnoses on a national level. Materials and Methods: The Kids' Inpatient Database was queried for diagnoses of operative CM-1 by International Classification of Disease-9 codes (348.4). Differences in preoperative demographics and perioperative complication rates between patient cohorts were assessed using Pearson's Chi-squared test and t-test when necessary. Binary logistic regression was utilized to find significant factors associated with complication rate. Certain surgical procedures were analyzed for their relationship with postoperative outcomes. Results: Thirteen thousand eight hundred and twelve CM-1 patients were identified with 8.2% suffering from a complication. From 2003 to 2012, the rate of complications for CM-1 pts decreased significantly (9.6%–5.1%) along with surgical rate (33.3%–28.6%), despite the increase in CM-1 diagnosis (36.3%–42.3%; all P < 0.05). CM-1 pts who had a complication were younger and had a lower invasiveness score; however, they had a larger Charlson Comorbidity Index than those who did not have a complication (all P < 0.05). CM-1 pts who experienced complications had a concurrent diagnosis of syringomyelia (7.1%), and also scoliosis (3.2%; all P < 0.05). CM-1 pts who did not have a complication had a greater rate of operation than those that had a complication (76.4% vs. 23.6% P < 0.05). The most common complications were nervous system related (2.8%), anemia (2.4%), and acute respiratory distress (2.1%). CM-1 pts that underwent an instrumented fusion (3.4% vs. 2.1%) had a greater complication rate as well as compared to those who underwent a craniotomy (23.2% vs. 19.1%; all P < 0.05). However, CM-1 pts that underwent a decompression had lower postoperative complications (21.3% vs. 28.9%; all P < 0.05). Conclusions: Chiari patients undergoing craniectomies as well as instrumented fusions are at a higher risk of postoperative complications especially when the instrumented fusions were performed on >4 levels.

Context: No consensus about classification, treatment, and clinical relevance of occipital condyle fractures (OCFs) exists. Aims: The aim of the study was to determine radiological, clinical, and functional outcome of OCFs and thereby determine its clinical relevance. Settings and Design: This was a retrospective analysis of a prospective follow-up study. Materials and Methods: From May 2005 to May 2008, all OCFs were included from a Level-1 trauma center. Patient files were reviewed for patient and fracture characteristics. Fracture classification was done according to the Anderson criteria. Clinical outcome was assessed by completing two questionnaires, radiological outcome by computed tomography imaging, and functional outcome by measuring active cervical range of motion using a Cybex EDI-320. Statistical Analysis Used: A Fisher's exact Test was used in categorical variables and a one-sample t-test for comparing means of active cervical range of motion in occipital fracture patients with normal values. An independent samples t-test was carried out to compare the means of groups with and without accompanying cervical fractures for each motion. Results: Thirty-nine patients were included (4 type I, 16 type II, and 19 type III). Twenty-seven patients completed follow-up, of whom 26 were treated conservatively. Fracture healing was established in 25 of 28 fractures at a median follow-up of 19 months. Eleven patients had none to minimal pain or disability at follow-up, 12 had mild, and two had moderate pain or disability on questionnaires. No statistically significant difference in active cervical range of motion was identified comparing means stratified for accompanying cervical fractures. Conclusions: Conservatively treated patients with an OCF generally show favorable radiological and clinical outcome.

Background: Published descriptions of the tectorial membrane have been inconsistent. Descriptions vary from a simple ligamentous band extending between the axis and occiput to a more complex layered structure composed of bands of fibers. The purpose of this study was to examine and document the macrostructure of the tectorial membrane. Materials and Methods: The tectorial membrane was examined by fine dissection in 11 formalin-fixed human adult cadavers. Detailed descriptions of the macrostructure and attachments were recorded. Results: Each tectorial membrane examined consisted of two distinct layers. The superficial layer was composed variably of three or four bands. Its fibers extend caudally over multiple spinal levels, becoming continuous with the posterior longitudinal ligament. The deeper layer routinely consisted of three bands, each being firmly adherent to the posterior aspect of the body of the second cervical vertebra. Attachments of fibers from both layers extended beyond the foramen magnum to create a semicircular attachment onto the base of the skull. Conclusions: The tectorial membrane has a more complex structure than has been described to date in standard anatomical texts. The existence of a layered and banded composition may have implications for understanding its function and for the clinical assessment of this structure.

Background: Relationship of atlantoaxial instability with Chiari formation is further analyzed in the report. Objective: The outcome of 25 patients who had failed conventional treatment for Chiari formation that included foramen magnum decompression surgery and were treated by atlantoaxial fixation is analyzed. Materials and Methods: During the period January 2010 to November 2019, we treated 25 patients who had undergone conventionally described surgical procedures; all included foramen magnum decompression for Chiari formation. None of the patients had any craniovertebral junction anomaly. All patients had syringomyelia. All patients had worsened in their neurological condition following surgery either in the immediate or in the delayed postoperative phase. Atlantoaxial instability was diagnosed on the basis of facetal alignment and on the basis of direct observation of joint status by bone manipulation during surgery. The patients were treated by atlantoaxial fixation. Goel clinical grading scale and Japanese Orthopedic Association Score assessed the clinical status both before and after surgery. Results: Following surgery, all patients improved in the clinical condition. The improvement began in the immediate postoperative period and progressed. During the follow-up period that ranged from 4 to 123 months, “significant” neurological recovery and amelioration of presenting symptoms were observed. During the period of follow-up, reduction in the size of syrinx was observed in 14 out of 18 cases where postoperative magnetic resonance imaging was possible. Conclusions: Clinical results reinforce the belief that atlantoaxial instability is the nodal point of pathogenesis of Chiari formation. Atlantoaxial fixation is the treatment.

Aim: An alternative technique of C1-2-3 fixation is described that blocks the critical anteroposterior odontoid process movements and retains rotatory movement at the atlantoaxial joint. The technique involves sharp section of the muscles attached to the C2 spinous process and C2-3 transarticular interfacetal screw fixation. Materials and Methods: We successfully used this technique of fixation in 14 cases wherein in similar case situation; we earlier advocated inclusion of C1 in the fixation construct. Eleven patients had multisegmental spinal degeneration, 1 patient had Hirayama disease, and 2 patients had ossified posterior longitudinal ligament. Results and Technical Advantages: The procedure avoids manipulating C1 vertebra and excludes it from the fixation process, disables movement of C2 vertebra but retains rotation movements of the atlantoaxial joint that are executed by the muscles attached to the transverse process of atlas. The net effect is that the anteroposterior odontoid process movements that threaten the cervicomedullary neural structures are blocked and the critical rotatory atlantoaxial movements are retained. Conclusions: The discussed technique can be useful for cases undergoing multisegmental fixation that includes atlantoaxial joint.

Background: Treatment option of postoperative discitis (POD) is either conservative or operative, but till date, there are no established validated protocols of the treatment of postoperative lumbar discitis. Aim: The aim of this study was to assess the outcome of conservative versus operative management of POD following single-level lumbar discectomy. Methods: We prospectively studied a total of 38 cases of POD. The patients were diagnosed clinically, radiologically, and by laboratory investigations and followed up with serial erythrocyte sedimentation rate (ESR), C-reactive protein, X-ray, computed tomography (CT), and magnetic resonance imaging. Demographic data, clinical variables, length of hospital stay, duration of antibiotic treatment, and posttreatment complications were collected, and pre- and postoperative assessment was done using the Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) score. Functional outcome of the study was measured by the modified criteria of Kirkaldy–Willis. Results: VAS score for pain was significantly decreased in both groups after treatment. However, posttreatment differences were not statistically significant. In posttreatment mean JOA score, differences were not statistically significant in both groups except the mean difference (−0.47) of restriction of daily activities, which was statistically significant (95% confidence interval: −0.88–−0.07, P = 0.025, unpaired t-test). About 73.7% and 84.2% of the patients had a satisfactory functional outcome in conservative and operative management groups, respectively, at the end of 12-month follow-up. Conclusions: Operative management yielded better outcomes than traditional conservative treatment in terms of functional outcomes, length of hospital stays, and duration of antibiotic treatment as determined by both the pain and daily activity levels.

Background: Despite the various treatment protocols available, survival evaluation is a fundamental criterion for the definition of surgical management; there are still many inconsistencies in the literature on this topic, especially in terms of the value of surgery and its morbidity in patients with very short survival. Objective: The objective was to analyze the association of clinical, oncological, and surgical factors in the survival of patients undergoing spinal surgery for spinal metastases (SM). Materials and Methods: A retrospective cohort of forty patients who were surgically treated at our institution for SM between 2010 and 2018 were included in the study. We applied the prognostic scales of Tomita and Tokuhashi in each patient and evaluated the systemic status using Karnofsky Performance Scale (KPS) and Eastern Cooperative Oncology Group Performance Scale. Survival rate in months was estimated using the Kaplan–Meier curve, with death considered as primary outcome and, for the evaluation of the association between the variables, the Chi-square test, Fisher's exact test, or Fisher–Freeman–Halton test was applied for better survival. The level of statistical significance was considered as 5% (P ≤≤ 0.05). Results: The mean survival was 8.4 months. Patients with KPS <70 had a mean survival of 6.36 months, while those with KPS >70 had a mean survival of 14.48 months (P = 0.04). The mean survival of patients classified as ECOG 2 was 7.05 months (95% confidence interval [CI]: 3.4–10.7), and that of patients classified as ECOG 3 and 4 was 1.24 months (95% CI: 0.8–1.59). The mean survival rate among the patients with unresectable metastases in other organs was 6.3 months (95% CI: 3.9–8.9), while the survival rate of those who did not have metastases was 13.8 months (95% CI: 10.0–17.68; P = 0.022). Conclusion: Survival was associated with the preoperative functional status defined by the KPS and ECOG scales and with the presence of nonresectable visceral metastases.

Context: The motion of the upper cervical spine (UCS) has a great interest for analyzing the biomechanical features of this joint complex, especially in case of instability. Although investigators have analyzed numerous kinematics and musculoskeletal characteristics, there are still little data available regarding several suboccipital ligaments such as occipito-atlantal, atlantoaxial, and cruciform ligaments. Objective: The aim of this study is to quantify the length and moment arm magnitudes of suboccipital ligaments and to integrate data into specific 3D-model, including musculoskeletal and motion representation. Materials and Methods: Based on a recent method, suboccipital ligaments were identified using UCS anatomical modeling. Biomechanical characteristics of these anatomical structures were assessed for sagittal and transversal displacements regarding length and moment arm alterations. Results: Outcomes data indicated length alterations >25% for occipito-atlantal, atlanto-axial and apical ligaments. The length alteration of unique ligaments was negligible. Length variation was dependent on the motion direction considered. Regarding moment arm, larger magnitudes were observed for posterior ligaments, and consistent alteration was depicted for these structures. Conclusion: These outcomes supply relevant biomechanical characteristics of the UCS ligaments in flexion-extension and axial rotation by quantifying length and moment arm magnitude. Moreover, 3D anatomical modeling and motion representation can help in the process of understanding of musculoskeletal behaviors of the craniovertebral junction.

Introduction: Chordoma is a rare sarcoma of the axial skeleton. The incidence of this tumor is different between races. To understand the epidemiologic characteristic and due to rarity of this pathology, large number of cases should be evaluated through national data registries. Materials and Methods: All pathologically confirmed cases of chordoma were derived from the Iran National Cancer Registry. Descriptive analysis was performed to extract age-standardized and age-specific incidence rates. Data regarding tumor location and chordoma subtypes were derived and analyzed. Results: One hundred twenty-two cases of chordoma including 80 male and 42 female were identified. One hundred seven cases of nonotherwise specified chordoma, 14 chondroid chordoma, and one dedifferentiated chordoma were detected. The age-standardized incidence rate (ASIR) of chordoma was 0.28. Chordoma of the sacrum composed 67.2% of cases. The mean survival time was 4.5 yearsConclusion: Epidemiology characteristic of chordoma in Iran is similar to other studies; however, the total ASIR was lower and the incidence in sacrum is nearly twice respect to the mobile spine. While men affected by sacral chordoma in relatively older age, the female patients had higher mean age in case of mobile spine involvement. The survival rate of chordoma is significantly lower in comparison with other studies.

Background: Chiari malformations (CM) are congenital defects due to hypoplasia of the posterior fossa with cerebellar herniation into the foramen magnum and upper spinal canal. Despite the vast research done on this neurological and structural syndrome, clinical features and management options have not yet conclusively evolved. Quantification of proper treatment planning, can lead to potential perioperative benefits based on diagnoses and days to procedure. This study aims to identify if early operation produces better perioperative outcomes or if there are benefits to delaying CM surgery. Aims and Objective: Assess outcomes for Chiari type I. Methods: The KID database was queried for diagnoses of Chiari Malformation from 2003-2012 by icd9 codes (348.4, 741.0, 742.0, 742.2). Included patients: had complete time to procedure (TTP) data. Patients were stratified into 7 groups by TTP: Same-day as admission (SD), 1-day delay (1D), 2-day delay (2D), 3-day delay (3D), 4-7 days delay (4-7D), 8-14 days delay (8-14D), >14 days delay (>14D). Differences in pre-operative demographics (age/BMI) and perioperative complication rates between patient cohorts were assessed using Pearson's chi-squared tests and T-tests. Surgical details, perioperative complications, length of stay (LOS), total charges, and discharge disposition was compared. Binary logistic regressions determined independent predictors of varying complications (reference: same-day). Results: 13,812 Chiari type I patients were isolated from KID (10.12 ± 6.3, 49.2F%, .063 ± 1.3CCI). CM-1 pts were older (10.12 yrs vs 3.62 yrs) and had a higher Charlson Comorbidity Score (0.62 vs 0.53; all P < 0.05). Procedure rates: 27.8% laminectomy, 28.3% decompression, and 2.2% spinal fusion. CM-1 experienced more complications (61.2% vs 37.9%) with the most common being related to the nervous system (2.8%), anemia (2.4%), acute respiratory distress disorder (2.1%), and dysphagia (1.2%). SD was associated with the low length of stay (5.3 days vs 9.5-25.2 days, P < 0.001), total hospital charges ($70,265.44 vs $90, 945.33-$269, 193.26, P < 0.001) when compared to other TTP groups. Relative to SD, all delay groups had significantly increased odds of developing postoperative complications (1D-OR: 1.29 [1.1-1.6] → 8-14D-OR: 4.77[3.4-6.6]; all P < 0.05), more specifically, nervous system (1D-OR: 1.8 [1.2-2.5] → 8-14D-OR: 3.3 [1.8-6.2]; all P < 0.05).Sepsis complications were associated with a delay of at least 3D(2.5[1.4-4.6]) while respiratory complications (6.2 [3.1-12.3]) and anemia (2 [1.1-3.5]) were associated with a delay of at least 8-14D (all P < 0.05).

Non-traumatic rotational atlantoaxial subluxation (NTARS) is rare and mostly reported after infection of the upper respiratory tract and named Grisel's syndrome. NTARS has also been reported after head-and-neck surgery, but it is extremely rare after otoplasty. A case of NTARS after bilateral otoplasty is reported under local anesthesia, a 15-year-old female being presented with painful torticollis. The diagnosis of atlantoaxial rotatory subluxation was performed using radiographs and computed tomography 2 weeks after the surgery. Closed reduction was performed by traction of the head and transoral direct pressure over an anterior dislocated C1 mass. The reposition of the joint was achieved, but it was very unstable, and it was not possible to keep the reduction. Open posterior reduction and posterior C1–C2 arthrodesis were performed followed by the use of a soft collar during 3 months.

A 28-year-old normotensive female presented with Horner's syndrome and paresthesia over the left side of the chest. Imaging study showed a large heterogeneous enhancing lesion in short-T1 inversion recovery sequence with flow voids in T2W sequence of magnetic resonance imaging. The lesion was located in the left-sided D1 and D2 regions extending into the neural foramina and apical part of the lung. During surgery, even minimal dissection of the tumor resulted in marked fluctuation in hemodynamic parameters, requiring temporary suspension of the surgery multiple times until hemodynamic parameters were brought under control by the anesthesiologist with drugs. The massive fluctuation in hemodynamic parameters in an unprepared and unanticipated scenario was a challenge for the anesthetist and surgeon. The tumor was radically excised with improvement of paresthesia in the immediate postoperative period, but Horner's syndrome persisted. After 18-months of follow–up, she was relieved of all symptoms including Horner's syndrome. Histopathological examination confirmed our suspicion as paraganglioma.

Morquio syndrome (MS) is an autosomal recessive defect caused by the deficiency of N-acetylgalactosamine-6-sulfatase. Odontoid hypoplasia, periodontoid soft tissue deposition, and cervical stenosis lead to myelopathy and quadriparesis in these patients. Craniovertebral junction instability in MS possesses a surgical challenge as bones are yet to completely ossify. The atlantoaxial dislocation (AAD) is reducible, and the need of transoral decompression for the soft tissue deposition ventral to odontoid is debatable. We present a series of four cases (mean age 4.3 ± 0.4 years) operated through posterior-only approach (n = 2, C1-lateral mass to C2 pars-interarticularis [Goel's technique]; n = 1 sublaminar wiring followed by C1-lateral mass to C2 pars-interarticularis; and n = 1 suboccipital plate with pars-interarticularis of C2 screw and pedicle of C3 and rod fixation). All patients had acceptable outcome and doing well at the last follow-up (12–96-follow-up). None of our patient needed transoral decompression. Patients with MS frequently manifest with spastic quadriparesis at an early age due to reducible AAD. Early surgical fixation with posterior C1–C2 screw and rod technique is recommended for the favorable surgical outcome and long-term stability of the cervical spine.