C1-C2 Injury: Factors influencing mortality, outcome, and fracture healing.

BACKGROUND: C1-C2 injury represents 25-40% of cervical injuries and predominantly occurs in the geriatric population. METHODS: A prospective multicentre study was conducted under the aegis of the french spine surgery society (SFCR) investigating the impact of age, comorbidities, lesion type, and treatment option on mortality, complications, and fusion rates. RESULTS: A total of 417 patients were recruited from 11 participating centres. The mean ± SD age was 66.6 ± 22 years, and there were 228 men (55%); 5.4% presented a neurological deficit at initial presentation. The most frequent traumatic lesion was C2 fracture (n = 308). Overall mortality was 8.4%; it was 2.3% among those aged ≤ 60 years, 5.0% 61-80 years, and 16.0% > 80 years (p < 0.001). Regarding complications, 17.8% of patients ≤ 70 years of age presented with ≥ 1 complication versus 32.3% > 70 years (p = 0.0009). The type of fracture did not condition the onset of complications and/or mortality (p > 0.05). The presence of a comorbidity was associated with a risk factor for both death (p = 0.0001) and general complication (p = 0.008). Age and comorbidities were found to be independently associated with death (p < 0.005). The frequency of pseudoarthrosis ranged from 0 to 12.5% up to 70 years of age and then constantly and progressively increased to reach 58.6% after 90 years of age. CONCLUSIONS: C1-C2 injury represents a serious concern, possibly life-threatening, especially in the elderly. We found a major impact of age and comorbidities on mortality, complications, and pseudarthrosis; injury pattern or treatment option seem to have a minimal effect.

Aneurysmal bone cyst of C2 treated with novel anterior reconstruction and stabilization.

PURPOSE: Aneurysmal bone cysts (ABC) form 1 % of primary bone tumors. Reported incidence rates are no more than 1.4 to 1,00,000. ABC of spine frequently involves posterior elements and commonly affects the lumbar spine (45 %). We present a case of C2 ABC for the challenges it poses due to the rarity of the lesion, tedious to access location, dilemmas relating to the suitable approach for tumor resection and technically demanding stabilization and reconstruction strategy post resection. METHODS: Clinical data analysis was performed to discuss a method of novel anterior column reconstruction following resection of a C2 aneurysmal bone cyst in a 8 year old child with anterior and posterior elements being involved. RESULTS: An 8-year-old girl with an aneurysmal bone cyst of the C2 vertebra underwent staged surgery following pre-operative embolisation. First a posterior approach tumor excision with posterior instrumented fusion was performed. Following which, using a modified anterior retropharyngeal approach anterior tumor excision and fibular graft reconstruction between the C1 lateral mass and C2 body was performed. Complete tumor clearance and stable reconstruction was successfully achieved in our patient. Patient showed excellent clinical outcome with radiological fusion. CONCLUSIONS: Preoperative embolisation in the treatment of ABC has supplemental advantage by reducing blood loss. Modified anterior retropharyngeal approach allows satisfactory clearance for C1-2 lesion and fibular strut graft between the C1 lateral mass and C2 body can provide a stable graft placement with good chance of fusion. Instability and spinal deformity, whether preexisting or post-excision, should be corrected with reconstruction and stabilization to offer best chance of cure in such cases.

Vertebral artery and osseous anomalies characteristic at the craniocervical junction diagnosed by CT and 3D CT angiography in normal Czech population: analysis of 511 consecutive patients.

There are numerous indications for stabilization using instrumentation of the upper cervical spine. This area is comprised of sophisticated anatomy. There is no study describing bony and vascular anomalies of this area in the middle European population. The main aim of this study was to investigate prevalence of any vertebral artery (VA) variations and osseous anomalies in the region of the craniocervical junction in a large sample of Czech patients based on three-dimensional computed tomographic angiography (3D CTA). The VA has a variable course through C2 before it passes above its groove on the posterior arch of C1. The artery can course more medially, more posteriorly or more superiorly, thus limiting the diameter of the bony elements used as landmarks for the safe insertion of metalwork. This is known as a high-riding VA (HRVA). The VA was considered HRVA in this study if the thickness of the C2 isthmus was less than 5 mm and/or the C2 internal height was less than 2 mm and/or the width of the C2 pedicle was less than 4 mm. The prevalence of ponticulus posticus (PP) was also identified. Following the VA variations in the V3 segment of the artery were persistent first intersegmental artery (FIA), fenestration (FEN) of the VA, and the posterior inferior cerebellar artery (PICA) branch originating from the C1/2 part of VA. Records of 511 patients from our institution were analyzed. The mean age of the patients was 63.6 years. One hundred and twenty-three (24.1 %) patients were identified to have HRVA, 30 (6 %) present on both sides. The age of patient over 70 years and female sex were found to be significant risk factors for HRVA presence. The prevalence of a nearby PICA branch was 4 %, FIA was 0.4 %, and FEN was 0.2 %. The presence of PP was identified in 14.3 % of patients. The HRVA and PP are common anomalies in the Czech population, and routine preoperative high-resolution CT evaluation is mandatory to prevent the VA injury when C1-C2 instrumentation is planned. The female sex and age over 70 years were found to be the most important factors for HRVA presence. The FIA and the FEN VA were rare in our study contrary to reports published from Asia, showing as many as a 10 % the VA presence over the starting point for C1 lateral screw. On the basis of the infrequent occurrence of these anomalies, we do not recommend routine CT angiography when upper cervical spine instrumentation in the normal population is planned.

Trans-oral fine needle aspiration cytology in cervical (C1 and C2) vertebral lesions: a novel diagnostic approach.

OBJECTIVE: Fine needle aspiration (FNA) cytology is a relatively non-invasive method for diagnosing both superficial and deep-seated neoplastic and non-neoplastic lesions. In this study, we evaluated the diagnostic utility of trans-oral FNA in cervical (C1 and C2) vertebral and paravertebral lesions. MATERIAL AND METHODS: Eighteen FNA cases of cervical vertebral and paravertebral lesions performed by a trans-oral route without any image-guidance between 1995 and 2014 were retrieved from the archives of the cytology department at PGIMER, Chandigarh and reviewed. RESULTS: Out of 18 cases, a definite diagnosis was given in 15 cases (83.3%). The commonest diagnosis seen was granulomatous inflammation consistent with tuberculosis (33.3%). CONCLUSION: Trans-oral FNA is a quick, inexpensive and relatively safe outpatient procedure for sampling C1 and C2 vertebral and paravertebral lesions, which are clinically and radiologically difficult to approach. It helps in the early diagnosis and management of these patients.

Pediatric Hangman's Fracture: A Comprehensive Review.

PURPOSE: Over 170 years ago, traumatic spondylolisthesis of the axis or hangman's fracture was described. Most descriptions of this entity have focused on adult presentations. METHODS: We review the literature on pediatric cases of hangman's fracture emphasizing the embryological as well as presentation aspects. RESULTS: The majority of cervical spine fractures in children occur at C1 and C2 vertebrae. A normal anterolisthesis of C2 can be seen in younger children and can mimic the anterolisthesis seen after traumatic spondylolisthesis. CONCLUSIONS: Traumatic spondylolisthesis of the axis in children requires further investigation due to the current emphasis in the literature on adult clinical findings and diagnostic challenges from the developmental immaturity of the pediatric skeleton.

Surgical management of an osteoblastoma involving the entire C2 vertebra and a review of literature.

PURPOSE: The purpose of this study was to evaluate the surgical management of an osteoblastoma involving the entire C2 vertebra. MATERIALS AND METHODS: A 14-year-old girl presented with unbearable neck pain. Her medical history was unremarkable. Computed tomography and magnetic resonance imaging revealed lytic and osteoblastic bone lesions involving the entire C2 vertebra. The tumor was resected in two stages with vertebral artery mobilization. Histological examination confirmed the diagnosis of osteoblastoma. The pain resolved postoperatively, and the patient had no further complaints. Sufficient fusion formation and no tumor recurrence with no complaints were seen in postoperatively 4 years. CONCLUSION: Marginal resection remains the best treatment for osteoblastoma of the spine. If tumor tissue surrounds the vertebral artery, the vertebral artery should be mobilized and the surrounding tumor mass excised.

A Rare Case of Primary Hyperparathyroidism Presenting as a C2 Brown Tumor-Plain Radiography Has yet again Proved Indispensable in Clinching the Diagnosis.

A brown tumor is one of the manifestations of hyperparathyroidism. It is a rare type of bone lesion that most often occurs in mandible, ribs, and large bones. Spinal involvement is extremely rare. We report an unusual case of a brown tumor of the axis vertebra in a 33-year-old male who presented to the orthopaedic clinic with posttraumatic C2 vertebra fracture and myelopathy. To plan further fixation and stabilization of C2 fracture, the patient underwent a plain radiograph and magnetic resonance imaging (MRI) of the cervical spine. The available routine chest radiograph at the time of MRI reporting clinched the diagnosis of primary hyperparathyroidism with a brown tumor of the axis vertebra. Thus, familiarity with subtle radiographic findings of this condition not only led to early diagnosis and appropriate treatment but also avoided unnecessary C2 biopsy and hardware fixation.

Rapid Recurrence of Giant Cell Tumour of C2 Vertebra After Long-Term Denosumab Following Surgical Resection.

A 25-year-old man presented with symptoms of cervical myelopathy for 10 days. Imaging revealed an expansile, lytic lesion involving the C2 vertebra completely and compressing the spinal cord, suggestive of giant cell tumor (GCT). Tumor resection and posterior stabilization from C1-C4 were done. Histopathology confirmed the diagnosis of GCT. The patient was kept on adjuvant Denosumab (D-ab) for two years with no signs of recurrence. However, discontinuation of D-ab therapy led to recurrence of the tumor within three months, which was managed with repeated surgical resection and anterior instrumentation followed by radiotherapy. To the best of our knowledge, this is the first reported case of GCT involving the upper cervical spine with rapid recurrence following the stoppage of D-ab therapy.

Aneurysmal Bone Cyst (ABC) of the C2 Vertebra.

An aneurysmal bone cyst (ABC) is a benign bone lesion commonly found in the younger age group. The principal aim of complete surgical excision to prevent recurrence in an ABC of the C2 vertebra presents a surgical challenge. We report a case of a 13-year-old with an ABC of the C2 vertebra and the strategies in its management surgically and pharmacologically.

Reconstruction after resection of C2 vertebral tumors: A comparative study of 3D-printed vertebral body versus titanium mesh.

Background: Surgical resection of C2 vertebral tumors is challenging owing to the complex anatomy of C2 vertebrae and the challenges to surgical exposure. Various surgical approaches are available, but some are associated with excessively high risks of complications. An additional challenge is reconstruction of the upper cervical spine following surgery. In the last decade, additive-manufacturing personalized artificial vertebral bodies (AVBs) have been introduced for the repair of large, irregular bony defects; however, their use and efficacy in upper cervical surgery have not been well addressed. Therefore, in this study, we compared instrumented fixation status between patients who underwent conventional titanium mesh reconstruction and those who underwent the same resection but with personalized AVBs. Methods: We performed a retrospective comparative study and recruited a single-institution cohort of patients with C2 vertebral tumors. Clinical data and imaging findings were reviewed. Through data processing and comparative analysis, we described and discussed the feasibility and safety of surgical resection and the outcomes of hardware implants. The primary outcome of this study was instrumented fixation status. Results: The 31 recruited patients were divided into two groups. There were 13 patients in group A who underwent conventional titanium mesh reconstruction and 18 group B patients who underwent personalized AVBs. All patients underwent staged posterior and anterior surgical procedures. In the cohort, 9.7% achieved total en bloc resection of the tumor, while gross total resection was achieved in the remaining 90.3%. The perioperative complication and mortality rates were 45.2% and 6.5%, respectively. The occurrence of perioperative complications was related to the choice of anterior approach (p < 0.05). Group A had a higher complication rate than group B (p < 0.05). Four patients (4/13, 30.8%) developed hardware problems during the follow-up period; however, this rate was marginally higher than that of group B (1/18, 5.6%). Conclusions: Total resection of C2 vertebral tumors was associated with a high risk of perioperative complications. The staged posterior and retropharyngeal approaches are better surgical strategies for C2 tumors. Personalized AVBs can provide a reliable reconstruction outcome, yet minor pitfalls remain that call for further modification.

Primary Ewing's sarcoma of the C2 vertebra with progressive quadriparesis: Report of a rare case and review of the literature.

BACKGROUND: Ewing's sarcoma is a malignant primitive neuroectodermal tumor (PNET) of childhood and adolescence. Primary Ewing's sarcoma of the spine is uncommon, and even more rarely involves the C2 vertebra. CASE DESCRIPTION: A 14-year-old patient was admitted with a history of chronic neck pain, which exacerbated after playing contact sports 3 weeks before presentation. On initial examination, he had pain radiating into the left upper extremity plus spasticity in all the four limbs. The cervical X-rays revealed a mixed sclerotic-lytic lesion involving the C2 vertebral body. The CT bony and soft-tissue windows documented predominant left-sided tumor invasion of the posterior elements, pedicles, and body of C2 along with extension into the spinal canal resulting in severe cord compression with peritumoral soft-tissue edema. The angiogram revealed a patent left vertebral artery entirely surrounded/encased by tumor. The PET-CT scan demonstrated no other spinal or systemic lesions. Due to his rapid neurological deterioration, the patient underwent an emergent biopsy of the tumor with posterior decompression and occipitocervical stabilization. The biopsy demonstrated a PNET (e.g., positive CD 99 MIC2 marker for Ewing's sarcoma). Following subsequent chemotherapy and radiation, the patient rapidly improved over a period of 3 months. CONCLUSION: Primary Ewing's sarcoma involving the C2 vertebra is exceedingly rare and warrants surgical decompression with pathological confirmation to provide additional multi-modal/multi-disciplinary adjunctive radiation/chemotherapy.

[Spinal navigation for posterior cervical and cervicothoracic instrumentation]. / Spinale Navigation zur dorsalen zervikalen und zervikothorakalen Instrumentierung.

OBJECTIVE: Safe placement of posterior cervical or high-thoracic pedicle screws, transarticular screws C1/2, translaminar screws C2 or cervical lateral mass screws under the guidance of spinal navigation. INDICATIONS: All posterior cervical and cervicothoracic instrumentation with screws: instabilities and deformities of rheumatoid, traumatic, neoplastic, infectious, iatrogenic or congenital origin; multilevel cervical spinal stenosis with degenerative instability or kyphosis of the affected spinal segment. CONTRAINDICATIONS: There are no absolute contraindications. SURGICAL TECHNIQUE: Prone position on a gel mattress, rigid head fixation, e.g., with Mayfield tongs; if appropriate, closed reduction under lateral image intensification; midline posterior surgical approach at the level of the segments to be instrumented; if necessary, open reduction; insertion of the cervical/upper thoracic screws under the guidance of spinal navigation; if necessary, posterior decompression; instrumentation longitudinal rods; if a fusion is to be obtained, decortication of the posterior bone elements with a high-speed burr and onlay of cancellous bone or bone substitutes. POSTOPERATIVE MANAGEMENT: In stable instrumentation, no postoperative immobilization with cervical collar is necessary. Drain removal on postoperative day 2-3, suture removal on postoperative day 14, clinical and x­ray control 3 and 12 months after surgery or in case of clinical or neurological deterioration. RESULTS: Numerous studies showed that the use of spinal navigation reduces implant malplacement rates significantly. Furthermore, it allows a reduction of the radiation dose for the operation team up to 90%.

Trabecular Anatomy of the Axis Vertebra: A Study of Shaded Volume-Rendered Computed Tomography Images.

BACKGROUND: To date, trabecular morphology studies have been conducted on thin-section computed tomography (CT) scans of cadaveric bone. Here we describe the trabecular anatomy of the axis vertebra as revealed by an innovative imaging tool. METHODS: Ten patients who underwent thin-slice CT scans for suspected cervical spine injury were prospectively subjected to shaded volume-rendered 3-dimensional reconstruction of the images. The trabecular anatomy thus depicted was recreated, and the mechanical vectors were deduced independently by a senior radiologist and spine surgeon and then matched. The clinical implications were postulated. RESULTS: The most striking trabeculae are the vertical compression trabeculae connecting the C1 facet to the C3 body. The center of the body of C2 has a space with sparse trabeculae; similarly, the pars interarticularis also has a clear void. The dens contain predominantly tensile trabeculae that are retained even in older patients. Midline remnants of the odontoid body synchondrosis persist even into late adulthood. CONCLUSIONS: Shaded volume-rendered imaging appears to be an excellent tool for studying the trabecular anatomy of cancellous bone. The weight-bearing trabeculae run from the C1-2 facet to the C3 body; the inferior facet contributes little to weight-bearing.

The Dens: A Review of its Diverse Nomenclature and a Recommended Simplified Terminology.

Pathology of the dens, such as fractures, demands precise terminology so that communication between physicians are succinct, diagnoses are accurate, and treatment strategies exact. This review aims to summarize the various terms used to describe the parts of the dens and recommend the ideal terminology. Using standard search engines, English language publications were searched for the many terms used to describe parts of the dens. A multitude of terms was identified with many demonstrating overlaps. Terms identified included apex, tip, apicodental, subdental, dentocentral and odontocentral junctions, peg, waist, base, neck, shaft, shoulder, and stem. Exact terminology is necessary when diagnosing or treating patients with pathology of or near the dens. The authors suggest simplified terminology for describing the parts of the dens that can be used in the future in order to be unequivocal and to avoid confusion when classifying and communicating fractures through its parts.

Comparison of Cervical Alignment and Clinical Outcomes in Patients with Os Odontoideum versus Non-Os Odontoideum after Atlantoaxial Fixation.

OBJECTIVE: The purpose of this study was to compare the effect of atlantoaxial fixation on cervical alignment and clinical outcomes in patients with os odontoideum (OO) versus non-os odontoideum (non-OO). METHODS: A total of 119 patients who underwent atlantoaxial fixation for instability were identified between January 1998 and January 2014. Inclusion criteria included age more than 21 years and diagnosis of OO and non-OO. There were 22 OO patients, and 20 non-OO patients. Measuring the Oc-C1 Cobb angle, C1-2 Cobb angle, C2-7 Cobb angle, and C2-7 sagittal vertical axis (SVA) was assessed. Clinical outcome was assessment of suboccipital pain was determined using a visual analogue scale (VAS), and Japanese Orthopedic Association (JOA) scores were obtained in all patients pre- and postoperatively. RESULTS: The preoperative C1-2 angle in the OO group (26.02°±10.53°) was significantly higher than the non-OO group (p=0.04). After C1-2 fixation, the OO group had significantly higher kyphotic change in the C1-2 angle (ΔC1-2) (3.2°±7.3° [OO] vs. -1.46°±7.21° [non-OO]) (p=0.04), and higher decrease in postoperative C2-7 SVA (ΔC2-7 SVA) (5.64±11.56 mm [OO] vs. -0.51± 6.57 mm [non-OO]) (p=0.04). Both groups showed improvements in the health related quality of life (HRQOL) after surgery based on the VAS and JOA score (p<0.001). CONCLUSION: After fixation, kyphotic angular change in atlantoaxial joint and decrease C2-7 SVA were marked in the OO group. Both the OO and non-OO groups improved in neurological function and outcome after surgery.

A novel screw guiding method with a screw guide template system for posterior C-2 fixation: clinical article.

OBJECT: Accurate insertion of C-2 cervical screws is imperative; however, the procedures for C-2 screw insertion are technically demanding and challenging, especially in cases of C-2 vertebral abnormality. The purpose of this study is to report the effectiveness of the tailor-made screw guide template (SGT) system for placement of C-2 screws, including in cases with abnormalities. METHODS: Twenty-three patients who underwent posterior spinal fusion surgery with C-2 cervical screw insertion using the SGT system were included. The preoperative bone image on CT was analyzed using multiplanar imaging software. The trajectory and depth of the screws were designed based on these images, and transparent templates with screw guiding cylinders were created for each lamina. During the operation, after templates were engaged directly to the laminae, drilling, tapping, and screwing were performed through the templates. The authors placed 26 pedicle screws, 12 pars screws, 6 laminar screws, and 4 C1-2 transarticular screws using the SGT system. To assess the accuracy of the screw track under this system, the deviation of the screw axis from the preplanned trajectory was evaluated on postoperative CT and was classified as follows: Class 1 (accurate), a screw axis deviation less than 2 mm from the planned trajectory; Class 2 (inaccurate), 2 mm or more but less than 4 mm; and Class 3 (deviated), 4 mm or more. In addition, to assess the safety of the screw insertion, malpositioning of the screws was also evaluated using the following grading system: Grade 0 (containing), a screw is completely within the wall of the bone structure; Grade 1 (exposure), a screw perforates the wall of the bone structure but more than 50% of the screw diameter remains within the bone; Grade 2 (perforation), a screw perforates the bone structures and more than 50% of the screw diameter is outside the pedicle; and Grade 3 (penetration), a screw perforates completely outside the bone structure. RESULTS: In total, 47 (97.9%) of 48 screws were classified into Class 1 and Grade 0, whereas 1 laminar screw was classified as Class 3 and Grade 2. Mean screw deviations were 0.36 mm in the axial plane (range 0.0-3.8 mm) and 0.30 mm in the sagittal plane (range 0.0-0.8 mm). CONCLUSIONS: This study demonstrates that the SGT system provided extremely accurate C-2 cervical screw insertion without configuration of reference points, high-dose radiation from intraoperative 3D navigation, or any registration or probing error evoked by changes in spinal alignment during surgery. A multistep screw placement technique and reliable screw guide cylinders were the key to accurate screw placement using the SGT system.