Predictive value of sagittal craniocervical roentgenographic parameters for HRQOL after craniocervical fusion.

PURPOSE: Loss of "physiological" sagittal alignment following craniocervical fusion (CCF) for degenerative disease may be associated with loss of horizontal gaze, dysphagia and poor HRQOL. This study reports on sagittal craniocervical roentgenographic predictors of HRQOL (SF-36) in patients following uncomplicated CCF for fresh upper cervical traumatic (UCT) injuries. METHODS: Twenty-two consecutive adult patients (group P) aged 50 ± 16 years, who had undergone CCF for fresh unstable C1 and C2AO/type UCT injuries, were evaluated 39 ± 12 months postoperatively with upright lateral cervical roentgenograms and SF-36as HRQOL measure. Physiological data for cervical sagittal alignment and SF-36 were taken from an age-matched control group (C) of 30 individuals aged 52 ± 12 years. Several commonly used sagittal cervical roentgenographic parameters were tested as potential predictors of the SF-36 domains in both groups. Roentgenographic predictors for each of the nine SF-domains were calculated using stepwise multilinear regression analysis (MLRA). RESULTS: The roentgenographic predictors in patients included (1) the angle created by McGregor's line and the inferior surface of the axis (OC2a) for physical function (PF, P = 0.049), role limitations due to physical health (RLPH, P = 0.004),role limitation due to emotional problems (RLEP, P = 0.004), emotional functioning (EF) (P = 0.012), social functioning (SF) (P = 0.028) and general health (GH, P = 0.041). (2) The angle formed between a horizontal line and the superior endplate of T1-vertebra (T1-slope) was predictor for SF (P = 0.017) and pain (P = 0.021), and (3) the angle between McGregor's line and the line that links the center of the C1 anterior arch and the apex of cervical sagittal curvature (PIA) was predictor for health change (HC, P = 0.002). CONCLUSIONS: This study showed that postoperative OC2a, PIA and T1-slope safely predict HRQOL outcomes (SF-36) following CCF for fresh trauma. It seems theoretically that the adequate restoration of the upper cervical alignment including C1-C2 upper cervical lordosis (OC2a) and PIA, in interaction with T1-slope, is important for postoperative HRQOL scores close to physiological values. The authors speculate that C0-C4 fusion restores horizontal gaze and allows for painful regain of pre-trauma quality of life. Spine surgeons should realign and stabilize the craniocervical junction taking in consideration these roentgenographic predictors.

Prevalence of high-riding vertebral arteries and narrow C2 pedicles among Central-European population: a computed tomography-based study.

High-riding vertebral artery (HRVA) and narrow C2 pedicles (C2P) pose a great risk of injuring the vessel during C2 pedicle or transarticular screw placement. Recent meta-analysis revealed a paucity of European studies regarding measurements and prevalence of these anatomical variants. Three hundred eighty-three consecutive cervical spine CT scans with 766 potential screw insertion sites were analyzed independently by two trained observers. C2 internal height (C2InH), C2 isthmus height (C2IsH), and C2P width were measured. Kappa statistics for inter- and intraobserver reliability as well as for inter-software agreement were calculated. HRVA was defined as C2IsH of ≤ 5 mm and/or C2InH of ≤ 2 mm. Narrow C2P was defined as C2P width ≤ 4 mm. STROBE checklist was followed. At least 1 HRVA was found in 25,3% (95% CI 21,1-29,8) of patients (16,7% of potential sites). At least 1 narrow C2P was seen in 36,8% (95% CI 32,1-41,7) of patients (23,8% of potential sites). Among those with HRVA, unilateral HRVA was present in 68,0% (95% CI 58,4-77,0), whereas bilateral HRVA in 32,0% (95% CI 23,0-41,6). No difference in terms of laterality (right or left) was seen neither for HRVA nor narrow C2P. Significant differences were found between females and males for all measurements. Each parameter showed either good or excellent inter- or intraobserver, and inter-software agreement coefficients. HRVA and narrow C2P are common findings in Central-European population and should be appreciated at the planning stage before craniocervical instrumentation. Measurements can be consistently reproduced by various observers at varying intervals using different software.

Risk of the high-riding variant of vertebral arteries at C2 is increased over twofold in rheumatoid arthritis: a meta-analysis.

Rheumatoid arthritis (RA) might lead to atlantoaxial instability requiring transpedicular or transarticular fusion. High-riding vertebral artery (HRVA) puts patients at risk of injuring the vessel. RA is hypothesized to increase a risk of HRVA. However, to date, no relative risk (RR) has been calculated in order to quantitatively determine a true impact of RA as its risk factor. To the best of our knowledge, this is the first attempt to do so. All major databases were scanned for cohort studies combining words "rheumatoid arthritis" and "high-riding vertebral artery" or synonyms. RA patients were qualified into the exposed group (group A), whereas non-RA subjects into the unexposed group (group B). Risk of bias was explored by means of Newcastle-Ottawa Scale. MOOSE checklist was followed to ensure correct structure. Fixed-effects model (inverse variance) was employed. Four studies with a total of 308 subjects were included in meta-analysis. One hundred twenty-five subjects were in group A; 183 subjects were in group B. Mean age in group A was 62,1 years, whereas in group B 59,9 years. The highest risk of bias regarded "comparability" domain, whereas the lowest pertained to "selection" domain. The mean relative risk of HRVA in group A (RA) as compared with group B (non-RA) was as follows: RR = 2,11 (95% CI 1,47-3,05), I2 = 15,19%, Cochrane Q = 3,54 with overall estimate significance of p < 0,001. Rheumatoid arthritis is associated with over twofold risk of developing HRVA, and therefore, vertebral arteries should be meticulously examined preoperatively before performing craniocervical fusion in every RA patient.

Radiological evolution of peri-odontoid pannus in a patient with Chiari I malformation: a case-based review.

INTRODUCTION: The Chiari I malformation (CIM) is commonly encountered by neurosurgeons and can have different etiologies and clinical presentations. CASE REPORT: We report a CIM patient who presented with symptoms of ventral brain stem compression and was found to have a large peri-odontoid pannus. Posterior fossa decompression was performed with a planned second-stage odontoidectomy. However, at the 6-month follow-up, postoperative images demonstrated a mostly resolved pannus and improvement of the brain stem compression symptoms, and the patient progressed uneventfully without the need for odontoidectomy. CONCLUSIONS: This case illustrates the resolution of a significant and symptomatic peri-odontoid pannus in a patient with CIM without craniocervical fusion or odontoidectomy. Such a case indicates that not all peri-odontoid pannus formations in CIM patients are due to hypermobility at the craniocervical junction.

Occiput/C1-C2 fixations using intra-laminar screw of axis - A long-term follow-up.

BACKGROUND: The surgical management of the craniocervical junction is challenging. Rigid posterior fixation of occiput/C1-C2 can be performed using a variety of surgical techniques including C2 pedicle/pars interarticularis, transarticular and intralaminar screw fixations. METHODS: Forty-one patients were treated with occipital plate/C1 lateral mass and C2 intra-laminar screw fixations for basilar invagination and congenital atlantoaxial subluxation, post-traumatic instability, tuberculous and rheumatoid arthritis-associated atlantoaxial dislocation. Out of forty-one, thirty-six patients had bilateral crossing intra-laminar screws and five had ipsilateral laminar screw fixation bilaterally. RESULTS: Follow-up was done in thirty-nine patients from 6 months to 8 years (mean: 21 months) and solid osseous fusion could be achieved in all (100%). One patient was lost to follow-up and another patient died of a cause unrelated to surgical technique. Pre-operative and post-operative Neurosurgical Cervical Spine Scale showed improvement in all patients having features of myelopathy. There were no neurological or vascular complications. However, nine patients had posterior laminar breach, eight had anterior laminar penetrations and three had wound infections. One patient had transient bulbar palsy and one patient had hardware failure in the form of avulsion of the midline occipital plate. CONCLUSIONS: Intra-laminar screw fixation is a safe alternative to transarticular and transpedicular/pars interarticularis fixation of C2 with advantage of having no risk of injury to vertebral artery and comparable biomechanical and pull-out strength.

Autologous rib graft for posterior cervical fusion in pediatric patients: efficacy and safety in the early postoperative period.

OBJECTIVE: The objective was to describe the indications, technique, and initial outcomes of autologous rib graft with recombinant human bone morphogenetic protein (rhBMP) in pediatric patients undergoing posterior cervical fusion. METHODS: A retrospective study was performed of all pediatric patients who underwent autologous rib grafting with extra-small rhBMP-2 for posterior craniocervical or cervical arthrodesis at a single institution between May 2020 and July 2023. Patients with less than 3 months of postoperative follow-up and no postoperative CT data were excluded. Primary outcomes included presence of fusion on CT, 30-day perioperative complications, and rib harvest complications. RESULTS: Twenty-eight sequential patients met inclusion criteria. Thirteen were male, 15 were female, and the average age was 9 years. There were no surgical site infections or instances of postoperative seroma or unplanned return to the operating room. All patients had solid fusion on postoperative CT at 3 months. The average follow-up was 14.5 months, with a range of 4 months to 3 years. There were no complications associated with the rib harvest, including no instances of harvest site pain, and all patient incisions healed well. CONCLUSIONS: The authors' preliminary results demonstrate that autologous rib graft with extra-small rhBMP-2 is an effective strategy to achieve a high rate of fusion in pediatric patients undergoing posterior instrumented craniocervical or cervical fusion. In this series, the authors found an acceptable safety profile, without seroma, surgical site infection, unplanned return to the operating room, or rib harvest complications.

The modified occipital condyle screw: A quantitative anatomic study investigating the feasibility of a novel instrumented fixation technique for craniocervical fusion.

Study Design: Prospective human anatomical study. Objective: Occipitocervical fusion with occipital plate or condyle screws has shown higher failure rates in those with skeletal dysplasia. The modified occipital condyle screw connects the occipital condyle to the pars basilaris of the occipital bone that may achieve fortified bony purchase and serve as a more rigid fixation point. We evaluate anatomical feasibility of a novel cranial fixation technique designed to decrease risk of pseudarthrosis. Materials and Methods: Occipital condyles were analyzed morphologically using multiplanar three-dimensional reconstructed, ultra-thin section computed tomography. The following parameters were obtained: occipital condyle length, maximal cross section, location of hypoglossal canal, axial and sagittal orientation of the long axis, occipital condyle pedicle (OCP) diameter, maximal length of OCP screw, and entry point. Results: Forty patients with total of 80 occipital condyles were analyzed and the following measurements were obtained: occipital condyle length 24.1 mm (20.5-27.7, standard deviation [SD]: 2.2); condyle maximum axial cross-section 12.6 mm (9-15.8, SD: 1.9); length of OCP screw 38.9 mm (29.3-44, SD: 5.7); diameter of OCP 3.4 mm (3.2-3.6, SD: 0.2); clearance below hypoglossal canal 4.5 mm (3.4-7, SD: 1.1); and distance of screw entry point from condylar foramen 2 mm (range 0-4, SD 1.6). Conclusion: The modified occipital condyle screw connects the condyle with the clivus through the pars basilaris and represents a safe and technically feasible approach to achieve craniocervical fusion in skeletally mature individuals. This cephalad anchor point serves as an alternate fixation point of the occipitocervical junction with increased strength of construct and decreased risk of hardware failure or pseudarthrosis given cortical bone purchase and longer screw instrumentation.

Manual Therapy and Exercise for the Management of Chronic Neck Pain With Multiple Neurovascular Comorbidities: A Case Report.

This case describes the clinical decision-making behind the conservative clinical management of an individual presenting with chronic neck pain with myriad neuromuscular comorbidities. The focus of this case report is to support the safe utilization of manual therapy and describe the tolerable prescription of strength and endurance exercise in a patient with numerous complications to improve self-efficacy. A 22-year-old female college student presented with a chief complaint of chronic, non-specific neck pain with comorbid Chiari malformation, migraines, upper cervical spinal fusion, Ehlers-Danlos syndrome (EDS), and postural orthostatic tachycardia syndrome (POTS) to an outpatient physical therapy clinic for evaluation and treatment. Following four sessions of physical therapy treatment, no clinically significant improvement in the individual's symptoms and daily function was achieved. Despite the lack of measurable change, the patient reported the program's value on her ability to self-manage her complex condition. The patient responded well to manual therapy, specifically thrust manipulations. In addition, both endurance and strengthening exercises were well tolerated and provided a measure of self-management that may not have been achieved before physical therapy management. This case report highlights the need for exercise and pain-modulating interventions in highly complex individuals to reduce medical intervention by advancing the patient's self-efficacy. There is a need for further research about the utility of standardized outcome measures, joint manipulations, and the addition of cervico-ocular exercises for those who present with neck pain and pertinent neuromuscular comorbidities.

The mandible-C2 angle: a new radiographic assessment of occipitocervical alignment.

BACKGROUND CONTEXT: Occipitocervical fusion is a rare and often challenging surgical procedure. Significant morbidity can result if care is not taken to achieve physiologic alignment. This is especially true for patients needing occipitocervical fusion in the setting of trauma where preoperative alignment is unknown. PURPOSE: To assess the radiographic angles normally subtended between the C2 body and the mandible ramus, in a series of patients with neutral physiologic alignment and no pathology, and to assess its validity as a possible intraoperative radiographic tool to determine a neutral craniocervical alignment. DESIGN: Validation and reliability study of radiographic parameters. PATIENT SAMPLE: Hundred lateral, neutral, cervical radiographs from patients with "normal" radiographic findings. OUTCOME MEASURES: Radiographic parameters of occipital-cervical alignment with assessment of reliability and correlation in data. METHODS: One hundred neutral lateral cervical spine radiographs in the upright position of patients with no complaints or known pathology were obtained from two medical clinics between December of 2014 and January of 2017. Three physicians, at different levels of spine surgery training, took measurements of radiographic parameters. The new technique used four different angles measured between the C2-body/dens complex and the mandibular ramus (anterior/posterior C2 body and anterior/posterior mandible lines angles), and compared these with the Occipito-C2 angle, which is a validated assessment of occipitocervical alignment. Statistical analysis was performed to assess correlation in data and measure reproducibility. RESULTS: Between the three reviewers, the mean±standard deviation were 18.0°±6.5° for Occipito-C2 angle (O-C2A), -4.2°±5.4° for anterior C2-body/anterior mandible line angle (AB/AM), -4.2°±5.9° for anterior C2-body/posterior mandible line angle (AB/PM), 5.1°±5.8° for posterior C2 body/anterior mandible line angle (PB/AM) and 5.6°±6.2° for posterior C2 body/ posterior mandible line angle (PB/PM). Overall the measurements obtained were correlative with an appropriate range for the standard deviation. Mean intraclass correlation coefficient were 0.889 for O-C2A, 0.795 for AB/AM, 0.859 for AB/PM, 0.876 for PB/AM, and 0.750 for PB/PM, showing high interobserver reliability for all the radiographic measures. Across the five techniques, 87%-92% of measurements fell within 10° of the median, 76%-83% fell within 7.5°, and 55%-66% within 5°. CONCLUSIONS: The mandible-C2 angle offers a reproducible alternative to the validated O-C2A technique for determining appropriate intraoperative occipitocervical alignment, which may be especially useful when preoperative radiographic alignment is unknown, such as occurs with trauma patients, with the goal of decreasing alignment-related complications in the setting of occipitocervical stabilization.

Transcondylar Odontoid Resection and Stabilization for Craniovertebral Degenerative Compression: 2-Dimensional Operative Video.

Non-neoplastic craniovertebral junction lesions are well known with various etiologies.1,2 They are frequently associated with craniovertebral junction instability. Many require only stabilization for their management.2 However, when significant irreducible anterior compression is present, surgical decompression becomes necessary.2-4 The traditional decompression route is direct anterior, such as the transoral, transmaxillary, or endoscopic endonasal approaches with a separate posterior stabilization.1,2 The transcondylar approach offers a wide and direct exposure to the anterolateral foramen magnum and atlantoaxial space, allowing extensive decompression, total resection of the odontoid, and associated pannus, even with large lateral extension, as well as fusion in the same surgical setting.5 The surgical manipulation is parallel to the dural sac in the sagittal plane, which could be safer than perpendicular dissection.5 Understanding the regional anatomy allows safe exposure and transposition of the vertebral artery with the surrounding alveolar and venous plexus (suboccipital cavernous sinus).5-7 We present this technique's details in a case of a 72-yr-old female who presented with progressively worsening bilateral upper extremity weakness and significant anterior compression due to irreducible odontoid degenerative changes. We demonstrate the steps necessary to achieve adequate exposure and decompression. The patient agreed to the surgical intervention. Images at 2:46, 3:00, and 3:25 reused from Al-Mefty et al,5 by permission from JNSPG. Images at 9:28 from Symonds et al,3 by permission of Oxford University Press. Image at 2:15, © Ossama Al-Mefty, used with permission.

Five-Level Anterior Cervical Discectomy And Fusion.

Anterior cervical discectomy and fusion (ACDF) is a common treatment modality that has shown good clinical results in patients with cervical degenerative disc disease. ACDF remains the procedure of choice for most patients given its satisfactory clinical outcomes and proven radiological fusion ranging from 90-100%. Five-level ACDF is a very rare type of surgery, even in large spine centers. This type of procedure is unique because, beyond three or four levels, the surgeon needs to switch from a transverse incision to a longitudinal incision along the medial sternocleidomastoid (SCM) muscle border, which is less preferred for cosmetic reasons. Another reason why this procedure is seldom performed is that extreme multilevel ACDF is associated with higher complication and failure rates. Literature covers one, two, and three-level anterior surgeries, but there are few studies reporting the outcomes of five-level ACDF. In the few studies that do report five-level ACDF, the data is controversial. Some studies show the risk of adjacent-segment disease increasing with a higher number of fused levels and increasing incidences of reoperation. Other studies show no changes in the risk of adjacent segment disease in multilevel ACDF in comparison with single-level ACDF. One study even showed a decreased level of adjacent-segment disease and reoperation rates in multilevel ACDF when compared to single-level ACDF. To contribute to current knowledge, we share our experience with five-level ACDF. We report the case of a 63-year-old female who presented with complaints of progressively worsening weakness in the upper extremities. MRI of her cervical spine demonstrated multilevel degenerative disc disease throughout C3-T1 with reversal of normal lordosis and a kyphotic deformity. We performed a successful ACDF at C3-T1 as well as partial corpectomy of the C5 and C6 vertebrae. We did it through a standard transverse incision from the midline to the medial border of the SCM within a preexisting neck crease, demonstrating that in select patients, extreme multilevel ACDF can be performed with proper anatomical dissection and without the need for multiple or longitudinal incisions.

Vascularized Bone Grafts for Spinal Fusion-Part 3: The Occiput.

BACKGROUND: Obtaining successful arthrodesis at the craniocervical junction and atlantoaxial joint can be more challenging than in other segments of the cervical spine. This challenge stems from the relatively hypermobile joints between the occipital condyles, the motion that occurs at C1 and C2, as well as the paucity of dorsal bony surfaces for posterior arthrodesis. While multiple different techniques for spinal fixation in this region have been well described, there has been little investigation into auxiliary methods to improve fusion rates. OBJECTIVE: To describe the use of an occipital bone graft to augment bony arthrodesis in the supraaxial cervical spine using a multidisciplinary approach. METHODS: We review the technique for harvesting and placing a vascularized occipital bone graft in 2 patients undergoing revision surgery at the craniocervical junction. RESULTS: The differentiation from nonvascularized bone graft, either allograft or autograft, to a bone graft using vascularized tissue is a key principle of this technique. It has been well established that vascularized bone heals and fuses in the spine better than structural autogenous grafts. However, the morbidity and added operative time of harvesting a vascularized flap, such as from the fibula or rib, precludes its utility in most degenerative spine surgeries. CONCLUSION: By adapting the standard neurosurgical procedure for a suboccipital craniectomy and utilizing the tenets of flap-based reconstructive surgery to maintain the periosteal and muscular blood supply, we describe the feasibility of using a vascularized and pedicled occipital bone graft to augment instrumented upper cervical spinal fusion. The use of this vascularized bone graft may increase fusion rates in complex spine surgeries.

Prevalence of High-Riding Vertebral Artery: A Meta-Analysis of the Anatomical Variant Affecting Choice of Craniocervical Fusion Method and Its Outcome.

OBJECTIVE: A high-riding vertebral artery (HRVA) has been defined as a C2 isthmus height of ≤5 mm and/or internal height of ≤2 mm measured 3 mm lateral to the border of the spinal canal. Its reported prevalence has varied widely. If overlooked during the approach for craniocervical fusion, injury to the vertebral arteries can occur, affecting the outcome. The present meta-analysis aimed to provide the pooled prevalence of HRVAs. METHODS: A comprehensive database search was conducted by 3 of us. Peer-reviewed studies that had followed the strict definition for HRVAs and had reported its prevalence were included. The risk of bias was assessed using the anatomical quality assessment tool. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. The pooled prevalence was calculated using a random effects model. RESULTS: The data from 20 studies with 3126 subjects (7496 sides) were analyzed. The overall pooled prevalence of ≥1 HRVA was 25.3% (95% confidence interval [CI], 19.6%-31.5%). The prevalence in those without the most important confounding factor, rheumatoid arthritis (RA), was 20.9% (95% CI, 16.5%-25.8%). Patients with RA had a prevalence of 42.9% (95% CI, 23.8%-63.1%). The difference between the non-RA and RA groups was statistically significant (P < 0.001, test of homogeneity, χ2). No geographical differences were noted (P = 0.20, test of homogeneity, χ2). Among those with HRVA, unilateral HRVA was present in 70.3% (95% CI, 65.2%-75.2%) and bilateral in 29.7% (95% CI, 24.8%-34.8%). No left or right side predilection was found (left, 50.8%; 95% CI, 33.8%-67.6%; right, 49.2%; 95% CI, 32.4%-66.2%). CONCLUSIONS: Craniocervical fusion should be preceded by examination of the vertebral arteries at the level of C2 because the presence of HRVAs is common and might preclude the safe insertion of transarticular or transpedicular screws.

Optimizing Alignment Parameters During Craniocervical Stabilization and Fusion: A Technical Note.

Proper craniocervical alignment during craniocervical reduction, stabilization, and fusion optimizes cerebrospinal fluid (CSF) flow through the foramen magnum, establishes the appropriate "gaze angle", avoids dysphagia and dyspnea, and, most importantly, normalizes the clival-axial angle (CXA) to reduce ventral brainstem compression. To illustrate the metrics of reduction that include CXA, posterior occipital cervical angle, orbital-axial or "gaze angle", and mandible-axial angle, we present a video illustration of a patient presenting with signs and symptoms of the cervical medullary syndrome along with concordant radiographic findings of craniocervical instability as identified on dynamic imaging and through assessment of the CXA, Harris, and Grabb-Oakes measurements.

Pediatric occipital condyle morphometric analysis using computed tomography with evaluation for occipital condyle screw placement.

OBJECTIVEOccipitocervical fusions in the pediatric population are rare but can be challenging because of the smaller anatomy. The procedure is even more exacting in patients with prior suboccipital craniectomy. A proposed method for occipitocervical fusion in such patients is the use of occipital condyle screws. There is very limited literature evaluating the pediatric occipital condyle for screw placement. The authors examined the occipital condyle in pediatric patients to determine if there was an age cutoff at which condylar screw placement is contraindicated.METHODSThe authors performed a retrospective morphometric analysis of the occipital condyle in 518 pediatric patients aged 1 week-9 years old. Patients in their first decade of life whose occipital condyle was demonstrated on CT imaging in the period from 2009 to 2013 at the Augusta University Medical Center and Children's Hospital of Georgia were eligible for inclusion in this study. Exclusion criteria were an age older than 10 years; traumatic, inflammatory, congenital, or neoplastic lesions of the occipital condyles; and any previous surgery of the occipitocervical junction. Descriptive statistical analysis was performed including calculation of the mean, standard deviation, and confidence intervals for all measurements. Probability values were calculated using the Student t-test with statistical significance determined by p < 0.05.RESULTSOverall, male patients had statistically significantly larger occipital condyles than the female patients, but this difference was not clinically significant. There was no significant difference in left versus right occipital condyles. There were statistically significant differences between age groups with a general trend toward older children having larger occipital condyles. Overall, 20.65% of all patients evaluated had at least one measurement that would prevent occipital condyle screw placement including at least one patient in every age group.CONCLUSIONSOccipital condyle screw fixation is feasible in pediatric patients younger than 10 years. More importantly, all pediatric patients should undergo critical evaluation of the occipital condyle in the axial, sagittal, and coronal planes preoperatively to determine individual suitability for occipital condyle screw placement.

Surgical Treatment of Skull Base Tumors, Extending to Craniovertebral Junction.

OBJECTIVE: To conduct a comparative analysis of 2 groups of patients with skull base chordomas extending onto the craniovertebral junction, who underwent surgical treatment using extracranial approaches with and without craniocervical fusion. METHODS: The study group included 29 patients with skull base chordomas, extending to the craniovertebral junction, who were operated on from 2000 to 2015. The patients underwent the following surgical treatment: posterior craniocervical fusion followed by tumor removal using transoral and combined transoral and transnasal approaches. The reference group included 21 patients with the same disease, who underwent tumor removal surgery using the transoral approach without craniocervical fusion. RESULTS: In the study group, in 27.5% of all cases (8 patients), the tumors were removed radically; in 65.5% of all cases (19 patients), the tumors were removed subtotally; and in 7% of all cases (2 patients), the tumors were removed partially. In the reference group, the extent of surgical radicality was as follows: radical, 0%; subtotal, 19% (4 cases); partial, 81% (17 cases). CONCLUSIONS: Use of the proposed surgical technique in clinical practice may help increase the radicality of tumor excisions, decrease the number of postoperative complications, accelerate the rehabilitation process, and increase the quality of life in patients with skull base tumors extending to the craniovertebral junction.

Computed Tomography-Based Occipital Condyle Morphometry in an Indian Population to Assess the Feasibility of Condylar Screws for Occipitocervical Fusion.

STUDY DESIGN: A retrospective computed tomography (CT)-based morphometric study of 82 occipital condyles in the Indian population, focusing on critical morphometric dimensions with relation to placing condylar screws. PURPOSE: This study focused on determining the feasibility of placing occipital condylar screws in an Indian population using CT anatomical morphometric data. OVERVIEW OF LITERATURE: The occipital condylar screw is a novel technique being explored as one of the options in occipitocervical stabilization. Sex and ethnic variations in anatomical structures may restrict the feasibility of this technique in some populations. To the best of our knowledge, there are no CT-based data on an Indian population that assess the feasibility of occipital condylar screws. METHODS: We measured the dimensions of 82 occipital condyles in 41 adults on coronal, sagittal, and axial reconstructed CT images. The differences were noted between the right and left sides and also between males and females. Statistical analysis was performed using the t-test, with a p-value of <0.05 considered significant. RESULTS: Mean sagittal length and height were 17.2±1.7 mm and 9.1±1.5 mm, respectively. Mean condylar angle/screw angle was 38.0°±5.5° from midline, with mean condylar length and width of 19.6±2.6 mm and 9.5±1.0 mm, respectively. Average coronal height on the anterior and posterior hypoglossal canal was 10.8±1.4 mm and 9.0±1.4 mm, respectively. The values in females were significantly lower than those in males, except for screw angle and condylar width. Based on Lin et al.'s proposed criteria, eight of 82 condyles were not suitable for condylar screws. CONCLUSIONS: Preliminary CT morphometry data of the occipital condyle shows that condylar screws are anatomically feasible in a large portion of the Indian population. However, because a small number of population may not be suitable for this technique, meticulous study of preoperative anatomy using detailed CT data is advised.

Sagittal range of motion after extensive cervical fusion.

BACKGROUND CONTEXT: Complicated cervical spine revision and deformity correction surgeries are becoming increasingly common. These challenging operations often necessitate fusion of the entire cervical spine. Patients frequently express concern over the likely loss of range of motion (ROM) of the neck postoperatively. However, we are aware of no study that specifically examines the sagittal cervical ROM after extensive cervical fusion. PURPOSE: To characterize sagittal ROM after extensive cervical fusion. STUDY DESIGN: Retrospective case series. PATIENT SAMPLE: Thirty patients were included. OUTCOME MEASURES: Radiographs at final follow-up were measured for cervical ROM by the occipitocervical and cervicosternal angles with the neck in full flexion and extension. METHODS: The surgical and medical records at one tertiary referral academic institution were used to identify adults who had undergone extensive cervical fusion between 1996 and 2008. An "extensive cervical fusion" entailed an upper instrumented vertebra proximal to C3 and lower instrumented vertebra distal to C7. Radiographs at final follow-up were measured for cervical ROM by the occipitocervical and cervicosternal angles with the neck in full flexion and extension. RESULTS: The average age at surgery was 58.3±10.0 years. The surgical levels were occiput-T1 (one patient), occiput-T4 (one patient), occiput-T6 (one patient), C1-T1 (one patient), C1-T2 (one patient), C2-T1 (nine patients), C2-T2 (eight patients), C2-T3 (six patients), and C2-T4 (two patients). Twenty-seven of the procedures were revisions. The other surgical indications were chin-on-chest deformity (one patient), cervical scoliosis (one patient), and multilevel cervical myelopathy (one patient). The mean follow-up period was 34.5±30.9 months (range, 6-154 months). The mean cervical ROM values by the occipitocervical and cervicosternal angles were 29.5±11.0° and 7.5±5.0°, respectively. The mean total cervical ROM value was 34.1±14.7°. CONCLUSIONS: A substantial degree of sagittal ROM can be maintained after extensive surgical fusion of the cervical spine.