The craniocervical junction (CCJ) is a complex and unique osteoligamentous structure that balances maximum stability and protection of vital neurovascular anatomy with ample mobility and range of motion. With the increasing utilization and improved resolution of cervical magnetic resonance imaging, craniocervical injury is being more accurately defined as a spectrum of injury that ranges in severity from overt craniocervical disassociation to isolated injuries of one more of the craniocervical ligaments, which may also lead to craniocervical instability. Thus, it is vital for the radiologist and neurosurgeon to have a thorough understanding of the imaging anatomy and function of the CCJ.

Introduction: Fractures of the upper cervical spine are often but not always amenable to either internal fixation or conservative management using a rigid cervical collar. For all other fractures in this area, management with a halo-vest orthosis is indicated, but it also has limitations. Here, we present an operative alternative to the halo-vest orthosis that provides more secure stability and less complications. Methods: Three patients presented to our hospital with atypical fractures of C1 and C2 and were given the choice of either a halo-vest orthosis or secure internal fixation without fusion and accepted the latter. Internal fixation without fusion from occiput to the subaxial spine was performed for all three and then removed-6 months later -after radiologic confirmation of healing. Results: All three patients underwent the procedure successfully and achieved and maintained acceptable alignment. Range of motion was preserved, and no intermediate-term issues were observed. Conclusion: Spanning internal fixation provides a safe and effective technique in the management of complex upper cervical spine injuries without the drawbacks of using a halo-vest orthosis.

Background: Pathophysiological mechanisms underlying the syringomyelia associated with Chiari I malformation (CM-1) are still not completely understood, and reliable predictors of the outcome of posterior fossa decompression (PFD) are lacking accordingly. The reported prospective case-series study aimed to prove the existence of a pulsatile, biphasic systolic–diastolic cerebrospinal fluid (CSF) dynamics inside the syrinx associated with CM-1 and to assess its predictive value of patients' outcome after PFD. Insights into the syringogenesis are also reported. Methods: Fourteen patients with symptomatic CM-1 syringomyelia underwent to a preoperative neuroimaging study protocol involving conventional T1/T2 and cardiac-gated cine phase-contrast magnetic resonance imaging sequences. Peak systolic and diastolic velocities were acquired at four regions of interest (ROIs): syrinx, ventral, and dorsal cervical subarachnoid space and foramen magnum region. Data were reported as mean ± standard deviation. After PFD, the patients underwent a scheduled follow-up lasting 3 years. One-way analysis of variance with Bonferroni Post hoc test of multiple comparisons was performed P was <0.001. Results: All symptoms but atrophy and spasticity improved. PFD caused a significant velocity changing of each ROI. Syrinx and premedullary cistern velocities were found to be decreased within the 1^st month after PFD (<0.001). A caudad and cephalad CSF jet flow was found inside the syrinx during systole and diastole, respectively. Conclusion: Syrinx and premedullary cistern velocities are related to an early improvement of symptoms in patients with CM-1 syringomyelia who underwent PFD. The existence of a biphasic pulsatile systolic–diastolic CSF pattern inside the syrinx validates the “transmedullary” theory about the syringogenesis.

Background: Presence of preoperative motor deficits in patients poses a distinct challenge in monitoring the integrity of corticospinal tracts during spinal surgeries. The inconsistency of the motor-evoked potentials is such patients, limits its clinical utility. D-wave is a robust but less utilized technique for corticospinal tract monitoring. The comparative clinical value of these two techniques has not been evaluated in the patients with preoperative deficits. Objectives: The objective of the study was to compare the predictive utility of myogenic Motor Evoked Potentials (m-MEP) and D-wave in terms of recordability and their sensitivity and specificity in predicting transient and permanent new motor deficits. Materials and Methods: Thirty-one patients with preoperative motor deficit scheduled to undergo spinal surgery were included in the study. Intraoperative m-MEP and D-wave changes were identified and correlated with postoperative neurology in the immediate postoperative period and at the time of discharge. Results: The mean preoperative motor power of the patient pool in left and right lower limb was 2.97 ± 1.56 and 3.32 ± 1.49, respectively. The recordability of m-MEPs and D-wave was observed to be 79.4% and 100%, respectively. The m-MEP predicted the motor deterioration in immediate postoperative period with 100% sensitivity and 80% specificity, while D-wave had 14% sensitivity and 100% specificity. At the time of discharge, m-MEPs' specificity reduced to 61%, while D-wave demonstrated 100% specificity. Conclusions: D-wave has a better recordability than m-MEPs in neurologically compromised patients. D-wave predicts development of long-term deficits with 100% specificity, while m-MEPs have a high sensitivity for transient neurological deficit. A combination of D-wave and m-MEP is recommended for monitoring the integrity of the corticospinal tract in patients with preoperative motor deficits.

Background: Implants' stability, especially in osteoporosis patients, is a challenging matter. Nowadays, the adoption of cannulated fenestrated screws augmented with polymethylmethacrylate cement (PMMA CSF) is described by some authors. This single-center, retrospective observational study aims to evaluate the long-term effectiveness, reliability, and mechanical performances of this type of screws in osteoporotic fractures. Materials and Methods: All the patients surgically treated from January 2009 to December 2019 with PMMA CSF were evaluated and submitted to the inclusion and exclusion criteria. Clinical and radiological evaluations were performed at pre- and post-surgery time and at the follow-up (FU). Loss of correction in the sagittal plane (bisegmental Cobb angle), kyphosis angle of the fracture (fractured vertebral angle), loosening of pedicle screws (screw's apex vertebral body's anterior cortex mean gap called SAAC gap and screw's apex vertebral body's superior endplate mean gap called SASE gap), visual analog scale, and Oswestry disability index scores were evaluated. Results: One hundred and sixty-three patients (58 males and 105 females) aged over 65 years affected by vertebral osteoporotic fractures were included in the study. At FU, we do not found significant differences in radiological items in respect to the postoperative period. Only one case of loosening and 18 cases of cement leaking (without neurological impairments) were found. Clinical scores improvement was significant in the interval between preoperative and FU. Conclusions: PMMA CSF seems to can guarantee good efficacy and effectiveness in the surgical treatment of vertebral fractures in osteoporosis.

Introduction: Nonosteoporotic burst vertebral fracture could commonly be treated with conservative or surgical approach. Currently, decision-making process is based on thoracolumbar (TL) AO spine severity injury score. However, some factors could affect posttraumatic kyphosis (PTK) and could be taken into account. The aim of the present study is to identify if axial and sagittal fracture shape and initial kyphosis are the risk factors for PTK. Materials and Methods: All consecutive patients treated between 2016 and 2017 for TL vertebral fracture with conservative treatment were retrospectively evaluated in the study. Only type A3 and A4 vertebral fractures were included in the study. Patients suffering from osteoporosis or other metabolic bone disease, aged above 60 years old were excluded from the study. Initial and 6 months X-ray from injury were analyze to evaluate local kyphosis and region of injury while initial assessment was performed with computed tomography to better identify fracture type and in some cases magnetic resonance imaging to exclude posterior ligament complex injury. Axial and sagittal view of the vertebral plate was analyzed and classified in three shapes according to fragment comminution and dislocation. Statistical analysis was performed trough STATA13 software. Student's t-test was used to evaluate the differences between initial and follow up kyphosis; odds ratio (OR) was used to evaluate the role of initial kyphosis, vertebral sagittal and axial fracture shape as a risk factor for PTK. Kruskal–Wallis test was used to assess the differences among vertebral shape fractures and final kyphosis. Fisher's exact test was used to assess the differences between fracture patterns and final kyphosis. Results: An initial kyphosis >10° ° (OR 36.75 P = 0.015), shape c vertebral plate (OR 147 P = 0.0015), and sagittal shape 3 (OR 32.25 P = 0.0025) are strongly related with PTK. Kruskal–Wallis test revealed a statistically significant difference among axial fracture shape (P < 0.0001) and sagittal fracture shape (P = 0.004) and also for initial kyphosis >10° (P < 0.0001). Fisher's exact test showed a significant difference for final kyphosis among pattern c3 and other patterns of fracture (P = 0.0001). Conclusions: A burst type lumbar vertebral fracture affecting a patient with initial local kyphosis >10° and comminution and displacement of vertebral plate and vertebral body is at high risk to develop a local kyphosis >20° in the follow-up if treated conservatively.

Background: Recurrent lumbar disc herniation (RLDH) is one of the major causes for failure of primary surgery. The optimal surgical treatment of RLDH remains controversial. Aim: Retrospectively, we evaluate 135 patients and compare the clinical outcomes between fusion and nonfusion treatment of RLDH. Methods: Records of 75 men and 35 women aged 28–60 years for conventional revision discectomy alone (nonfusion) and 15 men and 10 women aged 30–65 years for revision discectomy with transforaminal lumbar interbody fusion (TLIF) and transpedicular screw fixation (fusion) were reviewed. Demographics, surgical data, and complications were collected and pre- and postoperative assessment were done by the Visual Analogue Scale (VAS) scale and Japanese Orthopaedic Association (JOA) score. The results after surgery were assessed according to the recovery rate as excellent, good, fair, and poor. Results: The mean follow-up period was 28.8 and 24.6 months in Group A (nonfusion) and Group B (fusion group), respectively. The preoperative data between both the groups showed no statistically significant difference. The postoperative mean VAS and JAO scores, recovery rate, and satisfaction rate showed no statistically significant difference except postoperative low back pain and occasional radicular pain and neurological deficit in nonfusion group which was significantly higher than that of fusion group. In comparison to fusion group, nonfusion group required significantly less operative time, less intraoperative blood loss, less postoperative hospital stay, no blood transfusion, and less total cost of the procedure. Satisfaction rate was 80% and 88% in nonfusion and fusion groups, respectively. Conclusions: Both convention revision discectomy (nonfusion) and discectomy with instrumented fusion (TLIF) surgery are effective in patients with RLDH.

Background: Anterior cervical discectomy and fusion (ACDF) still represent the mainstream surgical approach in the treatment of degenerative cervical Degenerative Disc Disease (DDD), being a loss of mobility at the treated segment and adjacent segment diseases well-known complications. To overcome those complications, hybrid surgery (HS) incorporating ACDF and cervical disk arthroplasty is increasingly performed for DDD. Methods: We retrospectively reviewed the clinical, surgical, and outcome data of 62 consecutive patients (male/female, 29/37) harboring cervical disk herniation with or without osteophytes, with radiculopathy with or without myelopathy, who underwent a cervical discectomy on two or more levels with the anterior approach with at least one disk prosthesis along with cage and plate or O Profile screwed plate. Results: All the patients improved regardless of the cervical construct used. No significant relationship between different kind of prostheses as well as their surgical level, the number and the site of the cages (screwed and/or plated) was found out concerning immediate stability, dynamic prosthesis effectiveness, and clinical improvement in all the patients up to the maximum follow-up. Conclusions: Although the optimal surgical technique for cervical DDD remains controversial, HS represents a safe and effective procedure in selected patients with multilevel cervical DDD, as demonstrated by biomechanical and clinical studies and the present series. Some technical aspects should be considered when dealing with this procedure, like the drilling of the endplate, and some radiological findings have to be detected because potentially predictive of future misplacement.

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.

Background: Age-adjusted alignment targets in the context of distal junctional kyphosis (DJK) development have yet to be investigated. Our aim was to assess age-adjusted alignment targets, reciprocal changes, and role of lowest instrumented level orientation in DJK development in cervical deformity (CD) patients. Methods: CD patients were evaluated based on lowest fused level: cervical (C7 or above), upper thoracic (UT: T1–T6), and lower thoracic (LT: T7–T12). Age-adjusted alignment targets were calculated using published formulas for sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), pelvic tilt (PT), T1 pelvic angle (TPA), and LL-thoracic kyphosis (TK). Outcome measures were cervical and global alignment parameters: Cervical SVA (cSVA), cervical lordosis, C2 slope, C2–T3 angle, C2–T3 SVA, TS-CL, PI-LL, PT, and SVA. Subanalysis matched baseline PI to assess age-adjusted alignment between DJK and non-DJK. Results: Seventy-six CD patients included. By 1Y, 20 patients developed DJK. Non-DJK patients had 27% cervical lowest instrumented vertebra (LIV), 68% UT, and 5% LT. DJK patients had 25% cervical, 50% UT, and 25% LT. There were no baseline or 1Y differences for PI, PI-LL, SVA, TPA, or PT for actual and age-adjusted targets. DJK patients had worse baseline cSVA and more severe 1Y cSVA, C2–T3 SVA, and C2 slope (P < 0.05). The distribution of over/under corrected patients and the offset between actual and ideal alignment for SVA, PT, TPA, PI-LL, and LL-TK were similar between DJK and non-DJK patients. DJK patients requiring reoperation had worse postoperative changes in all cervical parameters and trended toward larger offsets for global parameters. Conclusion: CD patients with severe baseline malalignment went on to develop postoperative DJK. Age-adjusted alignment targets did not capture differences in these populations, suggesting the need for cervical-specific goals.

Objective: Morphology of bones of cervical vertebrae of dolphin was studied. When compared to human vertebrae the structural modifications in terms of functional needs are evaluated. Material: Morphological analysis of duly prepared bones of species D. delphis was carried out. Result: The craniocervical junction and cervical spine of the dolphin (Delphinus delphis) has unique adaptations to allow for dorsoventrally undulating swimming movements as well as leaping out of water. The key differences from the human cervical spine include the absence of an odontoid process limiting rotatory movements, disproportionately short and wide vertebral bodies and a unilaterally elongated transverse process of the axis. Moreover, the cervical spine of the dolphin is disproportionally short compared to humans. These modifications give strength and stability to the cervical spine allowing maximal agility for flexion-extension movements of the lumbocaudal spine, which are keys for propulsion. The unilaterally elongated transverse process likely allows for rotatory spinning, suggesting possible lateral dominance of rotatory spin in this species. Conclusions: Despite the skeletal adaptations, the cervical spine is strongly resonant of a mammalian heritage with a remarkably similar form and structure to house neurovascular contents and to allow muscular attachments.

The incidence of intramedullary spinal cord metastasis (ISCM) has been increasing because the overall survival of patients with cancer has improved thanks to recent advanced therapies, such as molecular targeted drugs, anticancer agents, and various irradiation techniques. ISCM from lung and breast cancer is the most common form among cases of ISCM. We report an extremely rare form of ISCM from gastric cancer. This 83-year-old man who had a past medical history of gastric adenocarcinoma presented with acute onset of paraparesis. Spinal magnetic resonance imaging revealed an intramedullary lesion at the upper thoracic level. Due to rapid worsening of his paresis, we decided to perform tumor extirpation. Gross total resection of the tumor was successfully performed. Pathological examination revealed poorly differentiated adenocarcinoma, suggesting the diagnosis of ISCM from gastric cancer. He demonstrated gradual improvement of paraparesis soon after surgery, although his overall survival was limited to about 6 months after surgery. When examining the etiology of acute paraparesis in elderly patients with a past medical history of cancer, ISCM should be considered in the differential diagnosis. The prognosis of ISCM from gastric cancer is still extremely limited. Unfortunately, there is currently no treatment with proven efficacy. Surgery for ISCM from gastric cancer, although a challenging procedure for spine surgeons, should be considered as a therapeutic option in these patients.

A spectrum of vertebral artery (VA) anomalies have been described with or without an associated congenital craniovertebral junction (CVJ) anomalies. C3 segmental VA, where the VA enters the dura at the level of C2/3 intervertebral foramen is an extremely rare anomaly. We report two cases of congenital CVJ anomaly (irreducible in one with C2/3 fusion and reducible in the other; without any subaxial fusion but with articular agenesis at C2/3 joint on the anomalous artery side). Computed tomographic angiography revealed intraspinal intradural entry of VA through the C2/3 intervertebral foramen on the right side with the contralateral artery found crossing the atlanto-axial joint. Both the patients underwent posterior approach and C2 was spared from instrumentation in both cases. Postoperatively, the patient with irreducible dislocation recovered well while the patient with reducible dislocation expired, possibly secondary to the thrombosis of the dominant VA from C2/3 foraminal encroachment. C3 segmental VA may be advantageous in aggressively exposing the C1/2 joint but instrumentation of C2 or C3 needs caution in view of the possibility of VA injury. Our experience shows that VA may be endangered even while exposing and protecting the artery. For such cases, we recommend posterior decompression of the C2/3 neural foramen during instrumentation in the absence of associated C2/3 fusion, as an abnormal joint morphology of C2/3 indicates a C2/3 instability.

Giant cell reparative granuloma (GCRG) is a benign nonneoplastic granulomatous lesion and is rare in the cranial bone. We present a pediatric case of this lesion arising from the condyle and lower clivus. A 9-year-old girl presented with slowly progressive hoarseness and dysphagia. She showed left glossopharyngeal, vagus, and hypoglossal nerve palsy. An osteolytic lesion around the lower clivus and condyle joint was accompanied by deformation of the craniovertebral junction. An endoscopic endonasal approach was used to decompress the cranial nerve and confirm the pathological finding. The lesion around the condyle was not resected to preserve occipito-cervical stability. The residual lesion has been observed carefully for 6 months, and regrowth has not occurred. GCRG is a rare granulomatous lesion in the cranial bone. This case is the first report of a pediatric clival GCRG. Treating pediatric GCRG may be helpful.

A relatively rare report of an 8-year-old girl with Maroteaux–Lamy syndrome that is Type VI mucopolysaccharidosis who presented with symptoms of spastic quadriparesis related to atlantoaxial instability is presented. Atlantoaxial stabilization resulted in rapid and sustained neurological recovery.

We present a report of two patients having the association of omovertebra, Sprengel's deformity of the shoulder and Klippel–Feil abnormality with craniovertebral junctional instability. Our literature survey did not locate any report of such association. Significance of bone alterations is analyzed. Two young patients presented with neck pain, torticollis, webbed neck, and spastic quadriparesis. In both patients, the investigations revealed basilar invagination, Klippel–Feil abnormality and Sprengel's deformity of the shoulder. Apart from these relatively common associations, both the patients had omovertebral bone that extended from the transverse process of C5 vertebra to scapula. Following atlantoaxial stabilization surgery, the patients rapidly recovered from all symptoms. Musculoskeletal abnormalities at the craniovertebral junction that include Klippel–Feil abnormality, Sprengel's shoulder, and omovertebra are secondary alterations to primary atlantoaxial instability.

A 16-year-old male presented with primary complaint of worsening dorsal spinal kyphoscoliosis (SKS) for 3 years. More recently, he developed spasticity in legs, breathlessness on mild exertion, and sleep apneas. Apart from SKS, investigations revealed rotatory atlantoaxial dislocation. Atlantoaxial fixation resulted in rapid recovery from all symptoms including from spinal deformity. Observations in this patient suggest that rotatory dislocation can be a cause of spinal deformity.