Flexion-extension X-rays Research Articles

Assessing accuracy of measurement methods for bony fusion assessment after anterior cervical discectomy

BACKGROUND CONTEXTCurrently, there is no universally accepted method for assessing radiological fusion shortly after anterior cervical discectomy. Five-year follow-up radiological X-rays demonstrating solid fusion or absence of fusion provided a gold standard for comparison with various assessment methods. PURPOSEEstablishing the most accurate diagnostic test for earlier bony fusion assessment by comparing different cut-off values for the difference in interspinous distance and the change in Cobb angle on dynamic radiological images against the established gold standard. DESIGNPost-hoc analysis from the NEtherlands Cervical Kinematics (NECK) trial (NTR1289). PATIENT SAMPLEA total of 40 patients with 1 level herniated disc that underwent anterior discectomy between 2010 and 2014 returned for a 5-year follow-up X-ray. OUTCOME MEASURESRadiological outcome was assessed quantitatively and qualitatively by fusion on radiographic images 5 years after surgery. METHODSRadiological dynamic X-rays were reviewed for fusion at 5-year follow-up by a senior spine surgeon. At this timepoint, bony continuity was indisputable and served as gold standard. Cobb angles and interspinous distances on flexion-extension images were measured independently by 2 investigators. Optimum agreement between the gold standard and the 2 methods was assessed, evaluating varying cut-off values, considering sensitivity, specificity, and area under the curve (AUC). RESULTSDynamic radiographic assessments revealed fusion in 29 out of 40 patients (mean age: 49 years ± 8; 23 women). For Cobb angle (optimal cut-off: ≤3.0°), the AUC was 0.86 with 100% sensitivity and 72.7% specificity. For interspinous distance (optimal cut-off: ≤1.5 mm), the AUC was 0.89 with 96.6% sensitivity and 81.8% specificity. The highest AUC (0.91) was observed for combined cut-off values (Cobb angle ≤3.0° and interspinous distance ≤2.0 mm), yielding 100% sensitivity and 81.8% specificity. CONCLUSIONThe combination of cut-off values ≤3.0° difference for Cobb angle and ≤2.0 mm difference for interspinous distance on lateral flexion-extension X-rays was assessed to be an accurate diagnostic criterion for fusion evaluation. This tool provides a practical and easy applicable method for assessing fusion during follow-up after anterior discectomy.

Multilevel Laminoplasty for CSM: Is C3 Laminectomy Better Than C3 Laminoplasty at the Superior Vertebra?

In a multilevel cervical laminoplasty operation for patients with cervical spondylotic myelopathy (CSM), a partial or complete C3 laminectomy may be performed at the upper level instead of a C3 plated laminoplasty. It is unknown whether C3 technique above the laminoplasty affects loss of cervical lordosis or range of motion. Patients undergoing multilevel laminoplasty of the cervical spine (C3-C6/C7) at a single institution were retrospectively reviewed. Patients were divided into two cohorts based on surgical technique at C3: C3-C6/C7 plated laminoplasty ("C3 laminoplasty only", N = 61), C3 partial or complete laminectomy, plus C4-C6/C7 plated laminoplasty (N = 39). All patients had at least 1-year postoperative X-ray treatment. Of 100 total patients, C3 laminoplasty and C3 laminectomy were equivalent in all demographic data, except for age (66.4 vs. 59.4 years, p = 0.012). None of the preoperative radiographic parameters differed between the C3 laminoplasty and C3 laminectomy cohorts: cervical lordosis (13.1° vs. 11.1°, p = 0.259), T1 slope (32.9° vs. 29.2°, p = 0.072), T1 slope-cervical lordosis (19.8° vs. 18.6°, p = 0.485), or cervical sagittal vertical axis (3.1 cm vs. 2.7 cm, p = 0.193). None of the postoperative radiographic parameters differed between the C3 laminoplasty and C3 laminectomy cohorts: cervical lordosis (9.4° vs. 11.2°, p = 0.369), T1 slope-cervical lordosis (21.7° vs. 18.1°, p = 0.126), to cervical sagittal vertical axis (3.3 cm vs. 3.6 cm, p = 0.479). In the total cohort, 31% had loss of cervical lordosis >5°. Loss of lordosis reached 5-10° (mild change) in 13% of patients and >10° (moderate change) in 18% of patients. C3 laminoplasty and C3 laminectomy cohorts did not differ with respect to no change (<5°: 65.6% vs. 74.3%, respectively), mild change (5-10°: 14.8% vs. 10.3%), and moderate change (>10°: 19.7% vs. 15.4%) in cervical lordosis, p = 0.644. When controlling for age, ordinal regression showed that surgical technique at C3 did not increase the odds of postoperative loss of cervical lordosis. C3 laminectomy versus C3 laminoplasty did not differ in the postoperative range of motion on cervical flexion-extension X-rays (23.9° vs. 21.7°, p = 0.451, N = 91). There was no difference in postoperative loss of cervical lordosis or postoperative range of motion in patients who underwent either C3-C6/C7 plated laminoplasty or C3 laminectomy plus C4-C6/C7 plated laminoplasty.

335 Development and Validation of a Predictive Score for Persistent Instability Following Conservative Treatment in Type II Odontoid Fractures

INTRODUCTION: Odontoid fractures are common cervical spine fractures, however significant controversy exists regarding their treatment. While risk factors for failure of conservative therapy have been identified, no predictive risk score has been developed to aid in decision making regarding surgical intervention or conservative therapy. METHODS: A retrospective review was conducted of all patients evaluated at a level one trauma center from 2005 to 2021. Patients identified with Type II Odontoid Fractures as classified by the Anderson D’Alonzo Classification system who were treated with external orthosis were included in analysis. Patients were considered to have failed conservative therapy if they were offered surgical intervention due to nonunion and continued motion on flexion extension x-rays. A machine learning method (RiskSLIM) was then utilized to created a risk stratification score to identify patients at high risk for requiring surgical intervention due to persistent instability. RESULTS: In total, 138 patients were identified as presenting with type II odontoid fractures that were treated conservatively. Of these, 38 patients demonstrated persistent instability following conservative therapy with cervical orthosis. The Odontoid Fracture Predictive Model (OFPM) was created using a machine learning algorithm with a five-fold cross validation area under the curve of 0.7389 (95% CI: 0.671 to 0.808) and calibration error of 18.6%. Predictive factors were found to include anterior or posterior displacement, displacement greater than 5 mm, comminution at the fracture base, and history of smoking. The probability of persistent instability was &lt;5% with a score of 0 and 88% with a score of 5. CONCLUSIONS: The OFPM model is a quick and accurate tool to assist in clinical decision making in patients with type II odontoid fractures.

Prevalence of Lumbar Segmental Instability in Young Individuals with the Different Types of Lumbar Disc Herniation-Preliminary Report.

Lumbar segmental instability (LSI) can cause pain and disability, and its background can be related to lumbar disc herniation (LDH). This retrospective study was conducted to analyze the prevalence of lumbar segmental instability (LSI) in young patients with different types of lumbar disc herniation (LDH). The study evaluated 133 individuals (18–25 years old) who suffered from LDH and underwent MRI and flexion-extension X-rays. Two groups were created: protrusion (PRO) and extrusion (EXT). LSI was scored positive when translatory motion was greater than 4 mm anteriorly or 2 mm posteriorly at the level of herniation. Statistica 13 was used to perform statistics. The LSI overall prevalence was 18.33% in PRO and 21.92% in EXT (p > 0.05). Out of all LSI positives, higher LSI incidence was observed in females compared to males; in PRO: 63.64%; in EXT: 68.75% (p > 0.05). LSI correlated positively with the passive lumbar extension test (PLE) (R = 0.32; p = 0.01) in the PRO group only. In summary, the results showed that the overall incidence of LSI was higher with severer disc damage. In addition, females were more prone to this pathology. However, the different types of LDH do not significantly affect the prevalence of LSI in young individuals.

Relationship between the morphology and composition of the lumbar paraspinal and psoas muscles and lumbar intervertebral motion in chronic low-back pain: An exploratory study.

Muscles of the lumbar spine play an important role in controlling segmental intervertebral motion. This study aimed to evaluate the association between lumbar intervertebral motion and changes in lumbar morphology/composition in people with chronic low-back pain (CLBP). A sample of 183 patients with CLBP participated in this cross-sectional study. Participants underwent lumbar flexion-extension X-rays to determine vertebral motion (translational and/or rotational motion) of lumbar levels (L1-L2 to L5-S1) and lumbar spine magnetic resonance imaging to quantify total and functional cross-sectional areas (CSAs) and asymmetry of the multifidus (MF), lumbar erector spinae (LES), and psoas muscles. The relationship between morphology/composition of the muscles and lumbar intervertebral motion was investigated. Smaller total and functional CSAs of the MF and greater CSAs of the LES muscle were observed in participants with greater intervertebral motion. Muscle asymmetry was observed at different lumbar vertebral levels. The greatest amount of translational intervertebral motion was observed at the L3-L4 level, while the greatest amount of rotational translation occurred at the L4-L5. Associations were observed between the morphology of the paraspinal muscles at the vertebral levels adjacent to the L3-L4 level and the increased intervertebral motion at this level. Relationships between measures of muscle morphology/composition and increased segmental vertebral motion were observed. The results may provide a plausible biological reason for the effectiveness of rehabilitating deficient paraspinal muscles in a subset of people with CLBP.

Treatment of cervical non-union with cervical disc replacement: A case series.

IntroductionCervical disc replacement (CDR) has become prevalent in the treatment of cervical pathology. CDR is an appealing option for several reasons, including improvement of symptoms, preservation of range of motion, and the absence of risk for nonunion – a complication of an anterior cervical decompression and fusion (ACDF) surgery. In this case series, we explore the use of CDR to treat cervical nonunion.MethodsFour patients, ages 50 to 64, presented to one surgeon with symptomatic cervical nonunion. Three of the four patients possessed risk factors for further nonunion and were therefore considered especially well-suited to a CDR rather than a revision ACDF. X-ray, MRI, and CT were used to confirm the presence of nonunion and to determine the architectural feasibility of replacing the level with a cervical disc arthroplasty. Six total nonunion levels were present in four patients (two levels in two patients and one level in two patients). Each of the nonunion levels was successfully treated with a revision decompression and CDR.ResultsPostoperatively, all four patients experienced improvement of nonunion symptoms. Neck Disability Index improved on average by 75% (preoperative score 51% to postoperative score 13%). Flexion-extension X-rays were available in three patients, which showed an increase in an average range of motion from 2 degrees to 7 degrees at the revised levels.ConclusionThe series describing four successful cases expands the current literature and provides support for future investigation into CDR as a treatment for cervical nonunion. We propose CDR as a viable option to treat symptomatic cervical nonunion and restore range of motion in patients without significant arthrosis and with preserved endplate architecture.

Case report of a retropharyngeal synovial cyst originate from atlantoaxial joint and review of the literature

Synovial cysts of the atlantoaxial joint are rare entities [1] and could possibly grow in any direction and compress adjacent structure. Synovial cysts of the atlantoaxial joint have been associated with atlantoaxial instability because of trauma or chronic inflammation. They could grow in the retropharyngeal space, lateral to the spine or towards the spinal canal either epidural or intradural and cause progressive myelopathy [2]. Rarely synovial cysts could cause acute clinical symptoms because of hemorrhage [5]. In this article, we present a case report of a 72 years old man presented with subtle upper neck pain and after cervical MRI (Magnetic Resonance Imaging) has been diagnosed with a retropharyngeal cystic mass originating from atlantoaxial arthrosis. Patient treated conservatively with analgetic medication. Neck pain went off without remission and there was no relapse during the last 5 years of follow up. Repeated cervical MRI revealed no change of the cyst size and morphology and patient remained asymptomatic. Atlantoaxial instability was not present in flexion extension x-rays. Laboratory results for rheumatoid arthritis were negative.

The application of C2 transpedicular screw, C1 laminar hook fixation and bone graft in the atlantoaxial instability

Traumatic atlantoaxial instability usually results from a motor vehicle accident, falls and motorcycle accidents. Atlantoaxial instability can lead to spinal cord compression and neck pain, but, spasticity and radicular symptoms as well. The purpose of surgery is to remove the compression and stabilize the joint permanently. To date, several surgical techniques have been described to remedy C1-C2 instability. In this study, the clinical and radiological outcomes of patients who operated with the C1 (Atlas bone) laminar hooks fixation and bilateral C2 (Axis bone) trans-pedicular screw technique were shown. Also, the advantages and disadvantages of this technique are discussed. From March 2010 to December 2017, 12 patients who have atlantoaxial instability were surgically treated by modified fixation technique which consists C1 laminar hooks fixation and bilateral C2 transpedicular screw. Twelve patients were operated with this procedure from March 2010 to December 2017. All the patients were checked with flexion-extension x-rays at the end of the twelfth week. The posterior bony fusion formation was observed on imaging in all patients. C2 bilateral pedicle screw combined with C1 laminar hook system is a good method for atlantoaxial instability in the conditions which is not convenient for insertion of C1 lateral mass and C2 trans-articular screw. However, this method may not be available in some cases such as traumatic, infection, neoplastic or degenerative pathologies in which the posterior arch of the atlas is damaged.

Short-term effectiveness of precise safety decompression via double percutaneous lumbar foraminoplasty and percutaneous endoscopic lumbar decompression for lateral lumbar spinal canal stenosis: a prospective cohort study

PurposeThis prospective cohort study reports on a modified technique, namely precise safety decompression via double percutaneous lumbar foraminoplasty (DPLF) and percutaneous endoscopic lumbar decompression (PELD) for lateral lumbar spinal canal (LLSC) stenosis, and its short-term clinical outcomes.MethodsThe study analyzed 69 patients with single-level LLSC stenosis simultaneously occurring in both zones 1 and 2 (defined as retrodiscal space and upper bony lateral recess respectively by new LLSC classification) who underwent DPLF–PELD from November 2018 to April 2019. Clinical outcomes were evaluated according to preoperative, 3 months postoperatively, and last follow-up, via leg pain/low back pain (LBP) visual analog scale (VAS) scores, Oswestry disability index (ODI) scores, and the Macnab criteria. The postoperative MRI and CT were used to confirm the complete decompression, and flexion-extension x-rays at the last follow-up were used to observe lumbar stability.ResultsAll patients successfully underwent DPLF–PELD, and the stenosis was completely decompressed, confirmed by postoperative MRI and CT. The mean follow-up duration was 13 months (range: 8–17 months). The mean preoperative leg pain VAS score is 7.05 ± 1.04 (range 5–9), which decreased to 1.03 ± 0.79(range: 0–3) at 3 months postoperatively and to 0.75 ± 0.63 (range: 0–2) by the last follow-up visit (p < 0.05). The mean preoperative ODI was 69.8 ± 9.05 (range: 52–85), which decreased to 20.3 ± 5.52 (range: 10–35) at the third month postoperatively and to 19.6 ± 5.21 (range: 10–34) by the final follow-up visit (p < 0.05). The satisfactory (excellent or good) results were 94.2%. There was one patient with aggravated symptoms, which were relieved after an open surgery. Two patients had a dural tear, and two patients suffered postoperative LBP. No recurrence or segmental instability was observed at the final follow-up.ConclusionDPLF–PELD could be a good alternative for the treatment of LLSC stenosis patients whose stenosis occurred in both zones 1 and 2.Trial registrationChinese Clinical Trial Registry (ChiCTR1800019551). Registered 18 November 2018.

The correlation between the severity of uncovertebral joints degeneration and heterotopic ossification after single-level artificial cervical disc replacement

Objective: To investigate the correlation between the severity of uncovertebral joints degeneration and heterotopic ossification (HO) after single-level artificial cervical disc replacement (ACDR). Methods: From January 2005 to January 2016, 70 patients who had undergone single-level ACDR in Peking University Third Hospital and had at least 5 years follow-up were included in this study. There were 35 males and 35 females with an average age of (42±8) years (range, 25-62 years). Cervical spine A-P X-rays were taken to assess the degeneration of uncovertebral joints and lateral X-rays were taken to assess the degeneration of intervertebral space. Cervical spine lateral and the flexion-extension X-rays at 5 years follow up were taken to assess HO. Degeneration of uncovertebral joints were evaluated by the classification system set-up in Peking University Third Hospital. Kellgren&Lawrence grading system was used to evaluate the degeneration of intervertebral space. HO was evaluated by the McAfee grading standards. The data were collected before surgery and at 5-years follow-up, then the correlation between degeneration of uncovertebral joints, degeneration of intervertebral space and HO was analyzed with Spearman non-parametric test. Results: The average follow-up time of 70 patients was (62.7±4.8) years (range, 52-74 months). There was a significant positive correlation between preoperative uncovertebral joints degeneration and HO after ACDR (r=0.585, P<0.01). There was a significant positive correlation between preoperative intervertebral space degeneration and HO (r=0.557, P<0.01). There was a significant positive correlation between preoperative intervertebral space degeneration and preoperative uncovertebral joints degeneration (r=0.727, P<0.01). Conclusion: There is a significant positive correlation between preoperative uncovertebral joints degeneration and HO after ACDR.

Analysis of translation and angular motion in loaded and unloaded positions in the lumbar spine

Background ContextAbnormalities in intervertebral rotation and translation are important to diagnosis and treatment planning for common spinal disorders. Tests that do not sufficiently load the spine can result in mis-diagnosed motion abnormalities. Upright flexion and extension x-rays are commonly used despite known limitations. Additional evidence is needed in support of preliminary studies suggesting that the change from standing to supine may sufficiently stress the spine to diagnose motion abnormalities. PurposeCompare intervertebral translation between flexion and extension to translation between upright and supine positions in a representative clinical population. Study Design/SettingProspective analysis of images retrospectively collected from routine clinical practices. MethodsAfter obtaining IRB approval for analysis of previously obtained images, patients were identified via chart reviews where a neutral-lateral x-ray and an MRI or CT exam were obtained for diagnosis of a spinal disorder and where flexion-extension x-rays had been obtained to help diagnose abnormal intervertebral motion. The mid-sagittal slice from the MRI or CT exam was paired with the neutral-lateral radiograph. Intervertebral translation at the L4-L5 and L5-S1 levels between supine and standing and between flexion and extension were measured from the images using previously validated methods. The translations were classified as normal or abnormal with reference to a previously obtained database of intervertebral motion in radiographically normal and asymptomatic volunteers. ResultsAt the L5-S1 level in particular, there tended to be greater translation between the supine and standing than between upright flexion and extension. On average, translations were below that found in asymptomatic volunteers. No abnormal translations were detected from flexion-extension radiographs whereas approximately 7% of levels had abnormal translations between supine and upright positions. ConclusionsIntervertebral translations between supine and standing, measured using the mid-sagittal slice from a MRI or CT exam and a lateral x-ray with the patient standing can help to identify abnormal motion. This would be particularly valuable for patients with limited flexion and extension. This study thereby adds to the evidence in support of measuring intervertebral motion between the supine and upright positions to detect abnormal intervertebral motion.

Endoscopic Surgical Resection of the Retropulsed S1 Vertebral Endplate in L5-S1 Spondylolisthesis: Case Series

Background A severe grade I and grade II spondylolisthesis at L5-S1 creates an anatomic distortion that can compress the traversing S1 nerve with a retropulsed S1 vertebral body endplate and (sometimes) herniated disc. Objectives To evaluate the feasibility for awake, endoscopic treatment of symptomatic radiculopathy secondary to the deformity that results from the retropulsed superior endplate of S1 in grade I/II L5-S1 spondylolisthesis in patients with and without previous fusion surgery. Study design Retrospective chart review. Setting This study took place in a single-center, academic hospital. Methods In 325 patients over 4 years there were 19 patients (8 with previous L5-S1 fusions and 11 without) treated with transforaminal endoscopic spine surgery for decompression of the neural foramen at L5-S1 in the setting of spondylolisthesis (at least 5 mm) and a retropulsed superior vertebral endplate of S1. Results The average preoperative Visual Analog Scale (VAS) back and leg scores were 6.1 and 6.7, and the average preoperative Oswestry Disability Index (ODI) score was 50.4. The average 1-year VAS back and leg scores were 2.2 and 2.2, and the average 1-year postoperative ODI score was 20.5. There was no statistically significant difference between the fusion and nonfusion groups. Patients treated were patients who presented with an S1 or L5 and S1 radiculopathy as their primary complaint and a L5-S1 spondylolisthesis of 5 mm or greater. Patients treated had no instability on flexion-extension x-rays. Eleven patients had not had fusions at L5-S1, and 8 patients had previous fusions at L5-S1 but still had a spondylolisthesis of at least 5 mm. The average slip for nonfusion patients was 8.4 mm, and the average slip for fusion patients was 8.8 mm. At 1-year follow-up the improvement in VAS back scores was 44% in the nonfusion group and 49% in the fusion group, and the improvement in VAS leg scores was 84% in the nonfusion group and 58% in the fusion group. At 1-year follow-up the improvement in ODI scores was 63% in the nonfusion group and 54% in the fusion group. Limitations Retrospective case series. Conclusions Awake, endoscopic surgery for the treatment of radiculopathy in the setting of a grade I/II L5-S1 spondylolisthesis is a viable minimally invasive treatment option for patients with radiculopathy in the setting of a stable L5-S1 spondylolisthesis with foraminal narrowing caused by a retropulsed superior endplate of the S1 vertebral body.

The Influence of Posture on Instability Evaluation Using Flexion-Extension X-Ray Imaging in Lumbar Spondylolisthesis.

Study DesignProspective clinical study.PurposeTo determine the optimal posture for instability evaluation using flexion–extension X-ray imaging in patients with lumbar spondylolisthesis.Overview of LiteratureCurrently, flexion–extension X-ray imaging is the most practical approach for the evaluation of lumbar instability. In flexion–extension X-ray imaging, achievement of the greatest segmental motion with flexion–extension movement is necessary. However, to our knowledge, currently, there is no standardized posture for determining lumbar instability.MethodsTwenty-three individuals with lumbar spondylosis related to the fourth vertebra underwent flexion–extension X-ray imaging in different postures (standing, sitting, and lateral decubitus positions), lumbar magnetic resonance imaging (MRI), and low back pain Visual Analog Scale (VAS) evaluation on the same day. Intervertebral angle, percent slippage, and intervertebral disc area ratio for different postures during flexion and extension were compared using Tukey’s method. The effect of low back pain and the association between MRI facet effusion and these measurements were investigated according to posture.ResultsThe percent slippage during extension (p=0.036), change in the percent slippage between flexion and extension (p=0.004), and change in the intervertebral angle (p=0.042) were significantly different between the sitting and lateral decubitus positions. There were also significant differences between the standing and lateral decubitus positions in the change in intervertebral angle (p=0.010). In patients with VAS score <40, there were significant differences in the intervertebral angle (p=0.011) between the standing and lateral decubitus positions, percent slippage (p=0.048), and intervertebral disk ratio (p=0.008) between the sitting and lateral decubitus positions. We found no relationship between MRI facet effusion and posture in terms of instability.ConclusionsIn this study, intervertebral instability was best evaluated in the lateral decubitus position when using flexion–extension X-ray imaging for patients with fourth lumbar vertebral spondylolisthesis.

Canadian Spine SocietyPresentation CPSS1: Spinal insufficiency fracture in the geriatric pediatric spinePresentation CPSS2: The clinical significance of tether breakages in anterior vertebral body growth modulation: a 2-year postoperative analysisPresentation CPSS3: Anterior vertebral body growth modulation for idiopathic scoliosis: early, mid-term and late complicationsPresentation CPSS4: Ovine model of congenital chest wall and spine deformity with alterations of respiratory mechanics: follow-up from

Canadian Spine SocietyPresentation CPSS1: Spinal insufficiency fracture in the geriatric pediatric spinePresentation CPSS2: The clinical significance of tether breakages in anterior vertebral body growth modulation: a 2-year postoperative analysisPresentation CPSS3: Anterior vertebral body growth modulation for idiopathic scoliosis: early, mid-term and late complicationsPresentation CPSS4: Ovine model of congenital chest wall and spine deformity with alterations of respiratory mechanics: follow-up from

New Classification and Its Value Evaluation for Atlantoaxial Dislocation.

ObjectiveTo introduce the TOI classification system (the Traction reduction type [T type], Operation reduction type [O type], and Irreducible type [I type] classification system) and to determine the interobserver and intraobserver reliability of the TOI classification system.MethodsBased on the characteristics of atlantoaxial dislocation (AAD), AAD was divided into Traction reduction type (T type), Operation reduction type (O type), and Irreducible type (I type). The analysis of interobserver and intraobserver agreements was done using kappa statistics. From July 2016 to January 2019, 213 AAD patients were retrospectively studied at four hospitals. Plain radiographs including extension and flexion views and three‐dimensional CT images were obtained. Twenty independent observers, including eight experienced spine specialists and 12 orthopaedic fellows from four different residency training hospitals, completed the survey.ResultsThe classification of the TOI system was based on etiology, the course of the disease, flexion–extension X‐rays, three‐dimensional CT reconstruction, and curative effects of skull traction. Flexion–extension X‐rays demonstrating a successful reduction of the dislocated atlantoaxial joint and three‐dimensional CT images showing osseous fusion of atlantoaxial facet joints and cervical traction reveal characteristics of T‐type. Furthermore, this type can be divided into two subtypes, T1 and T2, according to the etiology and course of the disease. Unsatisfactorily reduction after 1–2 weeks of strict cervical traction, no reduction shown on flexion–extension X‐rays, and no destruction or boneless fusion of atlantoaxial facet joints demonstrated in three‐dimensional CT images are characteristics of type O. Atlantoaxial facet joint showing bone fusion or failure of reduction after cervical traction or three‐dimensional CT images showing failure of surgical release are characteristics of type I. Interobserver and intraobserver reliability of the TOI classification system were moderate (κ = 0.543) and substantial (κ = 0.658), respectively. Interobserver and intraobserver reliability of the treatment choice were moderate (κ = 0.568) and substantial (κ = 0.675), respectively. There were no significant differences in the interobserver and intraobserver reliability between experienced spine specialists and fellows for all κ‐values (P > 0.05).ConclusionsThe TOI classification system had satisfactory reliability and, therefore, can be applied clinically and used by less experienced surgeons. We believe TOI can help surgeons choose appropriate treatment strategies.

Single-level Bryan cervical disc arthroplasty: evaluation of radiological and clinical outcomes after 18years of follow-up.

Many studies reported mid-term clinical and radiological outcomes after cervical disc arthroplasty. Only a few studies analysed the long-term results. The aim of the study was to evaluate the clinical and radiological outcomes in patients treated with single-level Bryan cervical disc arthroplasty after 18years of follow-up. This study was a retrospective analysis of institutional databases concerning patients treated with Bryan cervical disc arthroplasty. SF36 PCS, NDI and VAS were used to evaluate clinical and functional outcomes. Standard, flexion-extension X-ray and MRI were used to evaluate the radiological results. Fifty-seven patients treated with single-level Bryan cervical disc arthroplasty completed the 18-year follow-up. At the final follow-up, a residual movement was observed in 32 patients (56%). The treated level range of motion decreased from 10.1° pre-operatively to 6.1° at the last follow-up (p = 0.0021). The range of motion of the adjacent segments and of the cervical spine had no significant change. Disc degeneration of the adjacent segment after 18-year follow-up was observed in 77.1% of treated patients. The clinical and radiographic outcomes 18years after surgery are acceptable. The treated level range of motion reduction and the adjacent segment degeneration seems not to affect the clinical results after 18years of follow-up.

Assessing the Differences in Measurement of Degree of Spondylolisthesis Between Supine MRI and Erect X-Ray: An Institutional Analysis of 255 Cases.

Degenerative spondylolisthesis is the displacement of one vertebral body over the adjacent one. While standing and flexion-extension X-rays are preferred for determining listhesis, magnetic resonance imaging (MRI) is often utilized to assess the compression of nerve root or spinal cord. To investigate the difference in radiographic measurements of spondylolisthesis between X-rays and MRI. We retrospectively reviewed the records and radiographic images of patients with a confirmed diagnosis of spondylolisthesis undergoing operation in 2016. Primary variable of interest was the degree of slippage as per the Meyerding method. Agreement between the 2 reviewers was assessed using the 2-way intraclass correlation coefficient (ICC) for slippage percentage and Cohen's Kappa for grade. Agreement of Meyerding grade between the 2 imaging techniques was assessed using Cohen's Kappa, while the slip percentage measured for each technique was compared using a Bland-Altman (BA) plot, mean difference (MD), and 1-way ICC. A total of 255 cases were analyzed. ICC between the 2 reviewers was found to be 0.75 (95% confidence interval [CI]=0.64-0.83, P<.001) for X-ray and 0.76 (95% CI=0.66-0.83, P<.001) for MRI. Agreement between X-ray and MRI for grading of spondylolisthesis was found to be poor (kappa=0.32, P<.001). BA plot between X-ray and MRI measurements revealed an MD of 4.4% (95% limits of agreement: -10.3% to 19.3%) with 5.16% observations outside the limits of agreement and 1-way ICC of 0.35 showing poor agreement. Our results demonstrate the discrepancy of spondylolisthesis grade measurements between weight-bearing X-ray and nonweight-bearing MRI. Careful evaluation of both imaging technique is warranted to determine the final severity of pathology and tailoring of management plan.

Craniovertebral junction fixation in children less than 5years.

Whilst rigid fixation for craniovertebral instability is the gold standard, in very young, small children conventional management may have to be modified. We present a single-centre experience of craniocervical fixation in children under 5years. A retrospective review of cases that had undergone atlantoaxial (AA) or occipitocervical (OC) fixation aged under 5years. Fusion was assessed using computerised tomography or flexion extension X-rays. Twenty-six children (median age 2.3, range 0.8-4.9years, 19 under the age of 3) underwent OC (n = 19) or AA (n = 7) fusion between 1999 and 2016. Pathology comprised 17 congenital, five trauma, two tumour and two post-infection cases. Twenty-one patients underwent sublaminar cable fixation with calvarial, autologous bone graft and halo-body orthosis immobilisation. An occipital plate and rods to sublaminar wire construct were used in four cases. A rigid instrumented fixation with occipital plate and C2 pedicle screws was utilised in one case. Follow-up was for a median of 2.8years (range 0.03-16.3years). Initial fusion rate was 91%, reaching 100% following two re-operations. Ninety-two per cent of patients were neurologically stable or improved following surgery. Twenty-one patients had a good overall outcome. Two patients had post-operative neurological deteriorations, and four died due to non-procedure related causes. Pin site morbidity secondary to halo use occurred in five cases. High fusion rates with good outcomes are achievable using semi-rigid fixation in the under 5-year-olds. Full thickness, autologous calvarial bone graft secured with wire cables and halo external orthosis offers a safe and effective alternative technique when traditional screw instrumentation is not feasible. These slides can be retrieved under Electronic Supplementary Material.

Rigid Internal Fixation for Traumatic Cranio-Cervical Dissociation in Infants and Young Children.

Retrospective review. Evaluate radiographic and clinical outcomes for infants and children, who underwent rigid occipito-cervical fixation for traumatic craniocervical dissociation (tCCD). Traumatic craniocervical dissociation is devastating. Children are at high risk but make up a large number of survivors. Non-rigid fixation has traditionally been favored over screw and rod constructs due to inherent challenges involved with instrumenting the pediatric craniocervical junction. Therefore, outcomes for rigid occipito-cervical instrumentation in infants and young children with tCCD remain uncertain. Retrospective review of children who survived tCCD between 2006 and 2016 and underwent rigid occipito-cervical fixation. Fifteen children, from 8 months to 8 years old (mean, 3.8 yr), were either a passenger (n = 11) or a pedestrian (n = 4) in a motor vehicle accident. Seven patients had weakness: five with quadriplegia, one with hemiparesis, and one with bilateral upper extremity paresis. Ten patients had concurrent C1-2 instability. At last follow-up, four patients had improved motor function: one with bilateral upper extremity paresis and one with hemiparesis regained full strength, one with quadriplegia regained function on one side while another regained function in bilateral upper extremities. All underwent rigid posterior occipito-cervical fixation, with two patients requiring additional anterior and posterior fixation at non-contiguous levels. Fourteen patients were stable on flexion-extension x-rays at a mean follow-up of 31 months (9-1 yr or longer, 7-2 yr or longer). There were no cases of deformity, growth disturbance, or subaxial instability. Children who survive tCCD may regain function after stabilization. Rigid internal rod and screw fixation in infants and young children safely provided long-term stability. We advocate using C2 translaminar screws to exploit the favorable anatomy of pediatric lamina to minimize the risks of occipitocervical (OC) instrumentation. 4.

Lumbar rocking test: A new clinical test for predicting lumbar instability.

Purpose:Significant number of low back pain is caused by spinal instability. Clinical and radiological tests are used to diagnose lumbar instability, but the practical utility of clinical tests has not been studied extensively. Hence, it was decided to study lumbar rocking test and passive lumbar extension (PLE) clinical tests to identify their accuracy for lumbar instability, in comparison to the radiological assessment.Materials and Methods:This cross-sectional prospective study was conducted in 2017 at an Indian tertiary care center, after Ethics Committee approval. No financial transection involved anywhere at any stage of the study. Patients of 30–65 years having low back pain were included following informed consent. Clinical tests conducted were rocking test and PLE tests. All patients were subjected to a neutral anteroposterior, lateral and flexion-extension X-rays of lumbosacral spine. The association between clinical tests and lumbar instability was represented by Chi-square analysis. The rest of the findings were represented as descriptive statistics.Results:Fifty patients enrolled in the study, of which 28 (56%) were females. On X-rays, the maximum angular rotation and sagittal translation were seen at L5–S1 level. 35 (70%) and 46 (92%) patients showed positive PLE and rocking test, respectively. Significant association (P < 0.05) was seen between rocking test and lumbar instability. The sensitivity of rocking test was 95.56% and positive predictive value as 93.47%.Conclusion:Clinical tests can be used effectively for the diagnosis of lumbar spine instability. Rocking test was found to be accurate and sensitive for detecting subtle lumbar instability.