Cervical Spine Instrumentation Research Articles

An unexpected cause of intractable dysphagia after 20 years following cervical spine instrumentation using bone cement alone: a case report

An unexpected cause of intractable dysphagia after 20 years following cervical spine instrumentation using bone cement alone: a case report

Risk Factors for Adjacent Segment Problems after Posterior Instrumentation of the Cervical Spine

Adjacent segment problems after cervical spine instrumentation are widely reported. They can range from asymptomatic adjacent segment degeneration (ASD) noted on radiographs to symptomatic adjacent segment disease and even instability. While ASD following anterior instrumentation is well studied, there is a paucity of literature on ASD following posterior instrumentation. We intended to identify the risk factors associated with ASD following posterior instrumentation, focusing on pre-operative and surgical parameters. Eighty-seven patients who underwent posterior instrumentation of the cervical spine were recruited. Clinical and radiological examination was performed preoperatively and up to 24 months postoperatively. The collected data included patient demographics, indication for surgery, sagittal parameters (cervical lordosis, C2–7 sagittal-vertical axis), technique of surgery, number of levels instrumented and fused, number of levels decompressed, and the level at which the instrumentation ended. Based on postoperative evaluation, ASD was found in 29.9% of the patients, of which, one patient was symptomatic and required reoperation. Even though, according to our univariate analysis, reduced pre-operative cervical lordosis and the indication of degenerative spondylosis seemed to significantly influence the occurrence of ASD, multivariate regression analysis did not identify any independent risk factors. We also noted that, even though patients may develop ASD after the instrumented fusion of the cervical spine, this may not necessarily develop into symptomatic adjacent segment disease requiring revision surgery.

Transient Horner's Syndrome following Posterior Cervical Spine Instrumentation: A Postoperative Dilemma

Transient Horner's Syndrome following Posterior Cervical Spine Instrumentation: A Postoperative Dilemma

Clinical and radiological assessment of adjacent segment degenerative changes in cervical spine after instrumentation in indian scenerio

OBJECTIVE: Over the last 50 years many authors have used cervical spine fusion as a treatment for degenerative spondylotic conditions, and it has become the standard of care for numerous pathologic conditions of the spine. However, since over the past two decades spinal fusion has been performed on younger patients and the rates of cervical spine surgery have increased. Here we have studied the incidence of the adjacent segment disease and the radiological changes of cervical cord at the level of previous operation and at the adjacent segment. METHODS: Non randomised, open level study done at territory care centre for a period of three years a total 51 operated cervical spine patients were studied. MRI of cervical spine was done in symptomatic patients. All the patients were followed up clinically and radiologically. RESULTS: Fifty one patients were followed up for minimum of 2 years (average 72.82 months) after cervical spine instrumentation. 23 patients had single or multiple co- morbidities. 29 (56.86%) patients developed adjacent segment degeneration following the primary surgery. Rate of re- surgery for the symptomatic ASD was 9.8% , Development of radiological or clinical ASD 54.9%.

Intraoperative CT-angiography reconstruction of the vertebral artery utilizing neuronavigation and intraoperative i.v. contrast application for dorsal upper cervical axial and subaxial cervical spine instrumentation

Intraoperative CT-angiography reconstruction of the vertebral artery utilizing neuronavigation and intraoperative i.v. contrast application for dorsal upper cervical axial and subaxial cervical spine instrumentation

Operative Treatment of Cervical Spine Injuries Sustained in Youth Sports.

Little data exists on surgical outcomes of sports-related cervical spine injuries (CSI) sustained in children and adolescent athletes. This study reviewed demographics, injury characteristics, management, and operative outcomes of severe CSI encountered in youth sports. Children below 18 years with operative sports-related CSI at a Level 1 pediatric trauma center were reviewed (2004 to 2019). All patients underwent morden cervical spine instrumentation and fusion. Clinical, radiographic, and surgical characteristics were analyzed. A total of 3231 patients (mean, 11.3±4.6 y) with neck pain were evaluated for CSI. Sports/recreational activities were the most common etiology in 1358 cases (42.0%). Twenty-nine patients (2.1%) with sports-related CSI (mean age, 14.5 y; range, 6.4 to 17.8 y) required surgical intervention. Twenty-five were males (86%). Operative CSI occurred in football (n=8), wrestling (n=7), gymnastics (n=5), diving (n=4), trampoline (n=2), hockey (n=1), snowboarding (n=1), and biking (n=1). Mechanisms were 27 hyperflexion/axial loading (93%) and 2 hyperextension injuries (7%). Most were cervical fractures (79%) and subaxial injuries (79%). Seven patients (24%) sustained spinal cord injury (SCI) and 3 patients (10%) cord contusion or myelomalacia without neurological deficits. The risk of SCI increased with age (P=0.03). Postoperatively, 2 SCI patients (29%) improved 1 American Spinal Injury Association Impairment Scale Grade and 1 (14%) improved 2 American Spinal Injury Association Impairment Scale Grades. Increased complications developed in SCI than non-SCI cases (mean, 2.0 vs. 0.1 complications; P=0.02). Bony fusion occurred in 26/28 patients (93%) after a median of 7.2 months (interquartile range, 6 to 15 mo). Ten patients (34%) returned to their baseline sport and 9 (31%) to lower-level activities. The incidence of sports-related CSI requiring surgery is low with differences in age/sex, sport, and injury patterns. Older males with hyperflexion/axial loading injuries in contact sports were at greatest risk of SCI, complications, and permanent disability. Prevention campaigns, education on proper tackling techniques, and neck strength training are required in sports at high risk of hyperflexion/axial loading injury. Level III-retrospective cohort study.

Operative Treatment of Severe Cervical Spine Injuries Sustained in Youth Sports: Experience from a Pediatric Level 1 Trauma Center over a 16-Year Period

Background:Sports-related cervical spine injuries (CSI) are devastating traumas with the potential for permanent disability. There is a paucity of literature on operative CSI sustained in youth athletes.Hypothesis/Purpose:The aims of this study aims were to review injury characteristics, surgical treatment, and outcomes of severe pediatric CSI encountered in youth sports.Methods:We reviewed children less than 18 years old with operative sports-related CSI at a pediatric Level 1 pediatric trauma center between 2004−2019. All cases underwent modern cervical spine instrumentation and fusion. SCI were stratified according to the American Spinal Injury Association Impairment Scale (ASIA). Clinical, radiographic, and surgical characteristics were compared between groups of patients with and without spinal cord injury (SCI).Results:Three thousand two hundred and thirty-one children (mean, 11.3y±4.6y) were evaluated for CSI at our institution during the 16-year period. The majority of traumas resulted from sports/recreational activities and were seen in 1365 cases (42.3%). Of these, 171/1365 patients (12.5%) were admitted and 29/1365 patients (2.1%) required surgical intervention (mean age, 14.5y±2.88y; range, 6.4y–17.8y). Sports included: eight football (28%), seven wrestling (24%), five gymnastics (17%), four diving (14%), two trampoline (7%), one hockey (3%), one snowboarding (3%), and one biking injury (3%). Mechanisms were 19 hyperflexion (65%), eight axial loading (28%), and two hyperextension injuries (7%). The majority of operative CSI were fractures (79%) and/or subaxial defects (72%). Seven patients (30%) sustained SCI and three patients (10%) spinal cord contusion or myelomalacia without neurologic deficits. The risk of SCI increased with age (15.8y vs. 14.4y; p=0.03) and axial loading mechanism (71% vs. 14%; p=0.003).Postoperatively, two SCI patients (29%) improved 1 ASIA Grade and one (14%) improved 2 ASIA Grades. Increased complications developed in SCI than patients without SCI (mean, 2.0 vs 0.1 complications; p=0.02). Clinical and radiographic fusion occurred in 24/26 patients (92%) with adequate follow-up (median, 32 months). Ten patients returned to their previous activity and nine to sports with a lower level of activity.Conclusion:The overall incidence of sports-related operative CSI is low. Age- and gender discrepancies exist, with male adolescent athletes most commonly requiring surgery. Hyperflexion injuries had a good prognosis; however, older males with axial loading CSI sustained in contact sports were at greatest risk of SCI, complications, and permanent disability.Figure 1.1:Etiology of all cervical spine injuries between 2004-2019

Intraoperative Computed Tomography–Assisted Spinal Navigation in Dorsal Cervical Instrumentation: A Prospective Study on Accuracy Regarding Different Pathologies and Screw Types

Intraoperative computed tomography (iCT) navigated dorsal instrumentation has been successfully introduced as a new clinical standard. The proximity of vital anatomic structures makes cervical spine instrumentation an especially delicate task. Therefore, navigated approaches might prove to be beneficial. In this study, the accuracy of conventional instrumentation was compared with iCT navigated dorsal cervical spine instrumentation with focus on cervical pedicle screws (CPSs) versus lateral mass screws (LMSs) and pathologies. We analyzed a prospective consecutive series of patients undergoing cervical dorsal instrumentation with iCT and spinal navigation and retrospectively analyzed a cohort that received conventional cervical instrumentation with C-arm fluoroscopy (control group). Accuracy was assessed with a modified Gertzbein-Robbins classification. Underlying pathologies were taken into account regarding accuracy in different entities. Fifty-nine patients were treated using iCT (357 screws: 238 CPSs, 119 LMSs), and 98 patients underwent conventional instrumentation (632 screws: 69 CPSs, 563 LMSs). We achieved an initial accuracy of 93.28% (n= 220 screws) in the iCT group and 80.9% (n= 511 screws) in the control group (P < 0.001). Significant differences were found regarding the accuracy of CPS placement in cases of degenerative disorders (iCT vs. control; 94% vs. 63%; P < 0.001) and trauma (iCT vs. control; 88% vs. 72%; P < 0.05). iCT yielded favorable precision rates in regard to LMS placement (iCT vs. control; 94.2% vs. 82%; P < 0.05). Accuracy of iCT navigated instrumentation was significantly higher than conventional instrumentation. An overall tendency toward the use of CPSs with iCT navigation is evident, increasing the mechanical properties of the construct. iCT appears to be especially beneficial in elective surgery cases of degenerative spinal disorders.

Pipeline embolization for recurrent vertebral artery thromboembolic events secondary to a misplaced pedicle screw

Cervical spine instrumentation carries a risk of vertebral artery injury which can cause devastating neurological events. Flow diversion using the Pipeline embolization device (PED) is a commonly used endovascular modality that can treat various vessel wall abnormalities including aneurysms and arterial dissections. CASEDESCRIPTION: We report the case of a 69-year-old female who presented with multiple cryptogenic strokes secondary to a vertebral artery irregularity from a misplaced pedicle screw. She continued having ischemic infarcts despite maximal medical therapy. The patient was successfully treated with the PED and has not had any further ischemic events at 1-year follow-up. To our knowledge, this is the first published case of a chronic vertebral artery abnormality secondary to a misplaced pedicle screw that was treated with flow diversion. This is likely a safe and effective treatment for this rare complication of pedicle screw placement.

Acute Neurological Deficits in Instrumented Pediatric Cervical Spine Fusions

Recipient: Bram Verhofste, MD Acute Neurological Deficits in Instrumented Pediatric Cervical Spine Fusions Bram P. Verhofste, MD1; Michael P. Glotzbecker, MD2; M Timothy Hresko, MD2; Patricia Miller, MS1; Craig M. Birch, MD1; Michael Troy, BS1; Nora P. O'Neill, BA1; Lawrence I. Karlin, MD2; John B. Emans, MD2; Mark R. Proctor, MD2; Daniel J. Hedequist, MD2, (1) Boston Children's Hospital, Boston, MA, (2) Boston Children's Hospital, Harvard Medical School, Boston, MA Introduction: Pediatric cervical deformity is a complex disorder often associated with neurological deterioration requiring cervical spine fusion. However, little literature exists on new perioperative neurologic deficits in children. This study describes new perioperative neurologic deficits in pediatric cervical spine instrumentation and fusion. Methods: A single-center review of pediatric cervical spine instrumentation and fusion during 2002-2018 was performed. Demographics, surgical characteristics, and neurological complications were recorded. Perioperative neurologic deficits were defined as the deterioration of preexisting neurologic function or the appearance of new neurologic symptoms. Results: A total of 184 cases (160 patients, 57% male) with an average age of 12.6 ±5.30 years were included. Instability (n=63) and deformity (n=41) were the most frequent indications. Syndromes were present in 39% (n=71). Eighty-seven (48%) children presented with preoperative neurologic deficits (16 sensory, 16 motor, and 55 combined deficits). A total of 178 (96.7%) cases improved or remained neurologically stable. New neurologic deficits occurred in six (3.3%) cases: three hemiparesis, one hemiplegia, one quadriplegia, and one quadriparesis (Table 1, Figure 1). Preoperative neurologic compromise was seen in four (67%) of these new deficits (three myelopathy, one sensory deficit) and five had complex syndromes. Three new deficits were anticipated with intraoperative neuromonitoring changes (p=0.025). Three (50.0%) patients recovered within six months and the child with quadriparesis is expected to make a complete recovery. Hemiplegia persisted in one patient and one child died due a complication related to the tracheostomy. No association was found between etiology (p=0.46), preoperative neurological symptoms (p=0.65), age (p=0.56), halo (p=0.41), EBL (p=0.09), levels fused (p=0.09), approach (p=0.07), or fusion location (p=0.37). Conclusion: An improvement of the preexisting neurologic deficit or stabilization of neurologic function was seen in 96.7% of children after cervical spine fusion. New or progressive neurologic deficits occurred in 3.3% of the patients and occurred more frequently in children with preoperative neurologic symptoms. Patients with syndromic diagnoses are at higher risk to develop a deficit, likely due to the severity of deformity and the degree of cervical instability. Long-term outcomes of new neurologic deficits are favorable and 50% experienced complete neurologic recovery within six months.

Perioperative analgesia with erector spinae plane block for cervical spine instrumentation surgery.

Perioperative analgesia with erector spinae plane block for cervical spine instrumentation surgery.

Perioperative acute neurological deficits in instrumented pediatric cervical spine fusions.

Pediatric cervical deformity is a complex disorder often associated with neurological deterioration requiring cervical spine fusion. However, limited literature exists on new perioperative neurological deficits in children. This study describes new perioperative neurological deficits in pediatric cervical spine instrumentation and fusion. A single-center review of pediatric cervical spine instrumentation and fusion during 2002-2018 was performed. Demographics, surgical characteristics, and neurological complications were recorded. Perioperative neurological deficits were defined as the deterioration of preexisting neurological function or the appearance of new neurological symptoms. A total of 184 cases (160 patients, 57% male) with an average age of 12.6 ± 5.30 years (range 0.2-24.9 years) were included. Deformity (n = 39) and instability (n = 36) were the most frequent indications. Syndromes were present in 39% (n = 71), with Down syndrome (n = 20) and neurofibromatosis (n = 12) the most prevalent. Eighty-seven (48%) children presented with preoperative neurological deficits (16 sensory, 16 motor, and 55 combined deficits).A total of 178 (96.7%) cases improved or remained neurologically stable. New neurological deficits occurred in 6 (3.3%) cases: 3 hemiparesis, 1 hemiplegia, 1 quadriplegia, and 1 quadriparesis. Preoperative neurological compromise was seen in 4 (67%) of these new deficits (3 myelopathy, 1 sensory deficit) and 5 had complex syndromes. Three new deficits were anticipated with intraoperative neuromonitoring changes (p = 0.025).Three (50.0%) patients with new neurological deficits recovered within 6 months and the child with quadriparesis was regaining neurological function at the latest follow-up. Hemiplegia persisted in 1 patient, and 1 child died due a complication related to the tracheostomy. No association was found between neurological deficits and indication (p = 0.96), etiology (p = 0.46), preoperative neurological symptoms (p = 0.65), age (p = 0.56), use of halo vest (p = 0.41), estimated blood loss (p = 0.09), levels fused (p = 0.09), approach (p = 0.07), or fusion location (p = 0.07). An improvement of the preexisting neurological deficit or stabilization of neurological function was seen in 96.7% of children after cervical spine fusion. New or progressive neurological deficits occurred in 3.3% of the patients and occurred more frequently in children with preoperative neurological symptoms. Patients with syndromic diagnoses are at higher risk to develop a deficit, probably due to the severity of deformity and the degree of cervical instability. Long-term outcomes of new neurological deficits are favorable, and 50% of patients experienced complete neurological recovery within 6 months.

Intraoperative imaging and navigation for C1-C2 posterior fusion.

Background:Cervical axial spine fusion is challenging as the anatomy is extremely variable, and screw misplacement can lead to severe complications. C1 lateral mass screws and C2 pedicle screws are routinely placed under either fluoroscopic guidance or imaging-assisted navigation. Here, we compared the two for axial screw placement.Methods:We retrospectively evaluated patients’ treated from 2011–2016 utilizing the Harm’s procedure for C1-C2 screw fixation performed under either fluoroscopic guidance (nine patients) or image-assisted O-arm navigation (five patients). The groups had similar demographic and risk factors. Variables studied included operative time, estimated blood loss (EBL), accuracy of screw placement, screw reposition rates, and reoperation rates.Results:The mean EBL was 555CC and 260CC, respectively (not a significant difference) utilizing fluoroscopic versus O-arm navigation. Of interest, the mean surgical duration was 27 min longer in the O-arm versus fluoroscopy group (P = 0.03). Ten C2 pedicle screws were performed using O-arm navigation. Alternatively, as 9 of 18 C2 pedicles were considered “risky” for the placement of fluoroscopic-guided pedicle screws, laminar screws were utilized. Although the accuracy rate of C1 and C2 screw placement was higher for the navigated group, this finding was not significant. Similarly, despite complications involving two unacceptably placed screws from the fluoroscopic guidance group, there were no neurological sequelae.Conclusion:Axial cervical spine instrumentation is challenging. Utilization of Imaging-assisted navigation increases the accuracy and safety of screw placement.

Intraoperative Use of O-arm in Pediatric Cervical Spine Surgery.

Traditionally, fluoroscopy and postoperative computed tomographic (CT) scans are used to evaluate screw position after pediatric cervical spine fusion. However, noncontained screws detected postoperatively can require revision surgery. Intraoperative O-arm is a 3-dimensional CT imaging technique, which allows intraoperative evaluation of screw position and potentially avoids reoperations because of implant malposition. This study's objective was to evaluate the use of intraoperative O-arm in determining the accuracy of cervical implants placed by a free-hand technique using anatomic landmarks or fluoroscopic guidance in pediatric cervical spine instrumentation. A single-center retrospective study of consecutive examinations of children treated with cervical spine instrumentation and intraoperative O-arm from 2014 to 2018 was performed. In total, 44 cases (41 children, 44% men) with a mean age of 11.9 years (range, 2.1 to 23.5 y) were identified. Instability (n=16, 36%) and deformity (n=10, 23%) were the most frequent indications. Primary outcomes were screw revision rate, neurovascular complications caused by noncontained screws, and radiation exposure. A total of 272 screws were inserted (60 occipital and 212 cervical screws). All screws were evaluated on fluoroscopy as appropriately placed. Four screws (1.5%) in 4 cases (9%) were noncontained on O-arm imaging and required intraoperative revision. A mean of 7.7 levels (range, 5 to 13) were scanned. The mean CT dose index and dose-length product were 15.2±6.87 mGy and 212.3±120.48 mGy×cm. Mean effective dose was 1.57±0.818 mSv. There was no association between screw location and noncontainment (P=0.129). No vertebral artery injuries, dural injuries, or neurologic deficits were related to the 4 revised screws. Intraoperative non-navigated O-arm is a safe and efficient method to evaluate screw position in pediatric patients undergoing cervical spine instrumentation. Noncontained screws were detected in 9% of cases (n=4). O-arm delivers low radiation doses, allows for intraoperative screw revision, and negates the need for postoperative CT scans after confirmation of optimal implant position. Level IV.

Rigid segmental cervical spine instrumentation is safe and efficacious in younger children.

The utilization of cervical spine instrumentation in the young pediatric patient is not well reported. This study presents outcomes and complications of cervical spine instrumentation in patients who underwent cervical spine fusion surgery before age 10. Radiographic and clinical data were collected on all patients who underwent cervical spine surgery with instrumentation at a single institution between January 1, 2006, and March 31, 2015. Patients were ≤ 10years of age at the time of surgery with any cervical spine deformity/injury diagnosis. Patient demographics, details on cervical spine diagnosis, procedural data, imaging data, and postoperative follow-up data were collected. Twenty children met the criteria and were included in the study with a mean follow-up of 10.6months (3months-2years). Initial indication for cervical spine correction surgery included deformity (7 cases), trauma (6 cases), instability (3 cases), stenosis (2 cases), rotary subluxation (1 case), and infection (1 case). Fifteen cases were treated with adult 3.5-mm cervical spine instrumentation, 3 with wiring (1 sublaminar and 2 spinous process), and 2 with cannulated screws. Postoperative immobilization included 16 halo fixation, 3 collars, and 1 CTO. Overall, there were five complications related to the surgery. Two patients who had wiring (1 sublaminar and 1 spinous process) developed a non-union and required revision surgery (1 with cannulated screws and 1 with 3.5-mm segmental cervical spine instrumentation). One patient developed a postoperative infection that required incision and drainage. Five patients developed superficial pin infections for their halo. Two deformity patients experienced neurological complications that were likely unrelated to the cervical instrumentation. Rigid segmental fixation can be safe and efficacious when used in pediatric cervical spine patients. Whether used with halo or orthosis, patients experience minimal to no complications from the instrumentation and achieve successful fusion. Cervical spine wiring had a high risk of non-union requiring revision surgery. The incidence of wound infection was low with one in 20 cases.

Innovative use of fibreoptic bronchoscope as a flexible, manoeuvrable stylet during C-MAC videolaryngoscopy

The C-MAC videolaryngoscope has been used along with bougies, pliable metal stylet and optical stylet during the management of the difficult airway. The fibreoptic bronchoscope (FOB) was used as a last resort in our patient to direct the endotracheal tube into the trachea. A 74-year-old male (American Society of Anesthesiologists Physical Status III) who had undergone cervical spine instrumentation 12 years prior was scheduled for laparoscopic prostatectomy. On examination, he was found to have restricted neck movements. In view of the anticipated difficult airway, awake fibreoptic intubation was planned, for which the patient did not give consent. A FOB with a preloaded endotracheal tube was used as a flexible stylet. The fibrescope was manoeuvred towards the glottis which was visualised with the help of the C-MAC videolaryngoscope, resulting in successful intubation.

A Review of the Historical Evolution, Biomechanical Advantage, Clinical Applications, and Safe Insertion Techniques of Cervical Pedicle Screw Fixation.

Cervical spine instrumentation is evolving with an aim of stabilizing traumatic and non-traumatic cases of the cervical spine with a beneficial reduction, better biomechanical strength, and a strong construct with minimal intraoperative, as well as immediate and late postoperative complications. The evolution from interspinous wiring till cervical pedicle screws has changed the outlook in treating the cervical spine pathologies with maximum 3D stability, decreasing the duration of postoperative immobilization and hospital stay. Some complications associated with the use of cervical pedicle screw can be catastrophic. This review article discusses the morphometry of cervical pedicle; indications, biomechanical superiority, tricks, and pitfalls of cervical pedicle screw; complications and technical advancements in targeting safe surgery; and future directions of cervical pedicle screw instrumentation.

Benefits and pitfalls of iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) imaging in clinical application of the cervical spine MR

To evaluate efficacy of T2-weighted (T2W) iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)-fast spin echo (FSE) imaging of the cervical spine. The cervical spine of 100 symptomatic patients was imaged using routine magnetic resonance imaging (MRI) versus IDEAL-FSE imaging. The signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), and image quality were analysed. To compare the diagnostic efficiency of degenerative spondylopathy, evaluations of spondylolisthesis, retrolisthesis, disc herniation, myelopathy, disc degeneration, and bone marrow oedema were also performed. IDEAL-FSE showed significantly higher SNRs and CNRs (all p<0.001) than fat-suppressed (FS) T2W-FSE. Sixteen of 100 patients had cervical spine instrumentation; in those patients, IDEAL-FSE provided significantly better uniformity of fat suppression (p<0.001) and fewer metallic artefacts (p<0.001). For patients without instrumentation, FS T2W-FSE showed significantly better overall image quality (p<0.001) and homogeneity of the cerebrospinal fluid (CSF; p<0.001) with fewer motion artefacts (p<0.001). IDEAL-FSE, however, provided significantly better uniformity of fat suppression (p<0.001). There were no significant differences in the diagnoses of spondylolisthesis, retrolisthesis, disc herniation, or myelopathy between IDEAL and FS T2W images. The only significant differences between the IDEAL and FS T2W images were noted when diagnosing degenerative disc disease at the C2-3 and C5-6 disc levels (p=0.019, p=0.002, respectively) and bone marrow oedema at C3 vertebral body (p=0.029). T2W IDEAL-FSE imaging should only be considered as an additional sequence to conventional FS T2W images in patients with poor fat suppression or severe metallic artefacts.

Efficacy of Intraoperative Neurophysiologic Monitoring for Pediatric Cervical Spine Surgery

Clinical case series. To investigate the efficacy of intraoperative neuromonitoring in pediatric cervical spine surgery. Intraoperative neuromonitoring (IONM) consisting of somatosensory-evoked potentials (SSEP) and transcranial motor-evoked potentials (tcMEP) has been shown to effectively prevent permaneny neurologic injury in deformity surgery. The role of IONM during pediatric cervical spine surgery is not well documented. Advances in cervical spine instrumentation have expanded the surgical options in pediatric populations. The goal of this study is to report the ability of IONM to detect neurologic injury during pediatric cervical spine instrumentation. A single institution database was queried for pediatric-aged patients who underwent cervical spine instrumentation and fusion between 2011 and 2014. Age, diagnosis, surgical indication, number of instrumented levels, and a complete IONM were extracted. Sensitivity and specificity for the detection of neurologic deficits were calculated with exact 95% confidence intervals. Positive and negative predictive values were calculated with estimated 95% confidence intervals. Sixty-seven patients who underwent cervical spine instrumentation were identified with a mean age of 11.6 years (range 1-18). Diagnoses included instability (27), congenital (11), kyphosis (8), fracture (7), tumor (7), arthritis (4), and basilar invagination (3). Mean number of vertebral levels fused was 4 (range 2-7). All patients underwent cervical instrumentation with SSEP and tcMEP monitoring. A significant change in tcMEP monitoring was observed in 7 subjects (10%). There were no corresponding SSEP changes in these patients. The sensitivity of combined IONM was 75% [95% CI = 24.9, 98.7] and the specificity was 98.5% [92.7, 99.9]. tcMEP is a more sensitive indicator to spinal cord injury than SSEP, which is consistent with previous studies. IONM changes in 10% of a patient population are significant enough to warrant intraoperative determination if true SCI has occurred or is underway and intervene accordingly. 4.

A novel classification of screw placement accuracy in the cervical spine.

Goal of this study is to present an easily reproducible and reliable measurement to evaluate accuracy of screw placement in cervical spine. Accuracy of cervical screw position was assessed in 52 patients treated with 163 screws. Each patient receiving pedicle, transarticular C1/2, lateral mass, or laminar screws and postoperative CT scan was included. Placement position was categorized in 5 grades: Grade 1 is ideal with pedicle wall perforation < 1 mm, grade 2 < 2 mm, grade 3 < 3 mm, and grade 4 < 4 mm. Grade 5 > 4 mm and/or obstruction of transverse foramen by more than half a screw diameter. Intraclass correlation coefficient (ICC) values were assessed for inter- and intraobserver reliability. The mode of individual evaluations was calculated to assign a single value to each screw. This yielded 89 grade 1 (54.6%), 48 grade 2 (29.4%), 14 grade 3 (8.6%), 3 grade 4 (1.8%), and 9 grade 5 (5.5%) screws. Intraobserver reliability ICC was 0.966 and 0.959 for measurements. Interobserver reliability ICC was 0.938. This study introduces a reliable classification of cervical spine instrumentation with various screw types. This should enable the use of a uniform and reproducible, and thus comparable classification for screw position in cervical spine.