Magnetic resonance morphometry of the lumbar spinal canal in Zenica - Doboj Canton in Bosnia and Herzegovina.

Aim To investigate morphometric determinants of lumbar canal in patients treated in Cantonal Hospital Zenica, and their variation according to gender. Methods Morphometry of lumbar spinal canal was assessed in 52 patients treated at the Department of Neurosurgery of Cantonal Hospital Zenica in the period between September 2022 and November 2022. Data were collected retrospectively: anteroposterior and transverse diameter of lumbar vertebrae and intervertebral discs, as well as anteroposterior diameter of the spinal canal. Results Gender appeared to be an important morphometric determinant, since it significantly differed when it comes to lumbar vertebral anteroposterior and transverse diameter, being mostly larger in males. Conclusion This study increases anatomical knowledge of the vertebras and spinal canal of the lumbar region. Therefore, the measured dimensions of the lumbar vertebrae and spinal canal could be used as a baseline point for evaluation of patients presenting with low back pain and potential spinal canal stenosis.

Variation of Torg-Pavlov ratio with age, gender, vertebral level, dural sac area, and ethnicity in lumbar magnetic resonance imaging.

Objectives: The objectives of the study were to provide normal values of the Torg-Pavlov ratio (TPR) of the lumbar spine in magnetic resonance imaging (MRI) for the Jordanian population and examine differences observed according to factors including age, gender, lumbar level, dural sac area, or ethnic group. Material and Methods: Two hundred and eighteen lumbar MRIs from the Picture Archiving and Communication System were reviewed. These were collected from three main governmental hospitals, in North, Central, and South of Jordan. The mid-sagittal diameters of the vertebral body, spinal canal, and dural canal area were measured at all levels. Patients' gender and age were documented as well. Exclusion criteria were kyphoscoliosis alignments disorders, lumbar spinal canal compression regardless of the cause, vertebral bony disease (including fractures), and the presence of technical artifacts. Statistical analyses used descriptive and correlational methods. Comparisons were made between genders, age groups, lumbar level, dural sac area in the study population using independent t-test and one-way ANOVA tests, and between ethnicities by reviewing previous reports on subjects of different ethnicities. Results: The mean TPR ratio for the study participants was 0.4502 ± 0.097. The value of TPR was widest in the 20-29-year-old group at all vertebral levels and in both males and females. Females had a significantly wider TPR than males (P = 0.003) in all age groups. TPR differed significantly between the five vertebral levels (P = 0.026). The difference in TPR between age groups was not statistically significant. TPR showed a positive significant correlation with dural sac (r = 0.203, P = 0.003). Comparison with the previous literature demonstrated variation in the TPR where Jordanian population had a lower TPR in comparison with Negros and Caucasoids whereas similar to Koreans, especially in females. Conclusion: There are significant differences in TPR according to gender, dural sac area, lumbar spinal level (except between L1 and L2), and ethnic group, but no significant difference with the age was found. The present study has identified normal values of Torg's ratio in the Jordanian population. Although the study may not be able to provide clear guidelines for use in clinical practice, it has still highlighted possible between countries variations and has identified differences in these values to different factors. Implications on clinical practice could be reflected on the diagnosis of lumbar spinal stenosis or on predicting the prognosis of lumbar spine injury.

Pavlov's Ratio of the Cervical Spine in a Korean Population: A Comparative Study by Age in Patients with Minor Trauma without Neurologic Symptoms.

BACKGROUD: There are many studies on the vertebral body-to-canal ratio, the so-called Pavlov's ratio of the cervical spine. However, there are no studies on its relation with age to clarify each bony component's contribution to the spinal canal formation and its size. The aim of this study was to investigate differences and changes in the vertebral body-to-canal ratio according to age in an asymptomatic population. METHODS: This is a cross-sectional study of 280 asymptomatic individuals. A total of 140 men and 140 women representing each decade of life from the first to the seventh were included in this study. The anteroposterior length of the vertebral body and canal from C3 to C6 was measured on sagittal radiographs to calculate the vertebral body-to-canal ratio. RESULTS: The average Pavlov's ratio was significantly larger (p < 0.001) in the first decade of life. The average Pavlov's ratio of the individuals in the first decade of life was 1.09 between C3 and C6 (1.08 at C3, 1.07 at C4, 1.11 at C5, and 1.13 at C6; range, 0.78-1.51). There was no significant difference among the other decades of life. CONCLUSIONS: We assessed the Pavlov's ratio of the cervical spine in an asymptomatic population. It is our belief that the spinal canal size is the largest in the first decade of life, and the Pavlov's ratio becomes almost fixed throughout life after maturity.

Outcome and predictive factors in rapid progressive cervical spondylotic myelopathy: A retrospective case-control study.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a major cause of cervical spinal cord dysfunction in people over 55 years of age. Most patients with CSM usually present with chronic and phased compression, however, some patients with CSM develop rapid severe neurological dysfunction without any trauma. To our knowledge, markers that can be used for early identification of patients with potential to develop rapid neurological deterioration have not been totally identified. Here, we evaluate epidemiological, clinical and radiographic features associated with the development and prognosis of rapid progressive cervical spondylotic myelopathy (rp-CSM). METHODS: A retrospective study was carried out for 175 patients diagnosed with CSM between March 2011 and January 2017 at West China Hospital. Patients were divided into rp-CSM group and chronic CSM (c-CSM) group based on the time taken for neurological deterioration to occur and the severity of preoperative neurological dysfunction. The clinical outcomes were assessed using the Modified Japanese Orthopaedic Association (mJOA) score, and imaging parameters such as Torg-Pavlov Ratio (TPR), intervertebral disc level compression ratio and increased signal intensity (ISI) on T2W1. Multivariate analysis was used to compare the outcomes between the two groups and identify potential predictors for rapid neurological dysfunction in CSM patients. RESULTS: Out of the 175 patients enrolled in the study, 25 developed rp-CSM (18 males; median age 59.04 ± 12.81 years) and the remaining 75 (54 males; median age 56.88 ± 12.31 years) were used as controls for the study (c-CSM group). The average time taken to develop severe neurological deterioration was 0.8 month in rp-CSM group and 24 month in c-CSM group (p = 0.001), while the preoperative mJOA scores were 6 in rp-CSM patients and 12 in c-CSM patients (p = 0.014). In addition, rp-CSM patients demonstrated worse outcomes than the controls in one year after surgery (mJOA improvement rate 54.5 % and 80 %, respectively, p = 0.021). There were no differences in the clinical parameters evaluated between the two groups except for the history of diabetes and smoking. Analysis of radiographic parameters indicated that TPR MRI, intervertebral disc level compression ratio and increased signal intensity (ISI) on T2W1 were poor in rp-CSM patients compared to c-CSM patients. Regression analysis also showed that the history of diabetes, TPR MRI < 0.4, compression ratio ≥50 %, and the sagittal diameter of ISI ≥ 50 % of spinal canal diameter on T2W1 were strongly associated with the rapid progressive neurological dysfunction in patients with CSM. CONCLUSION: The prognosis of rapid progressive CSM is worse than that of common chronic CSM. The rapid neurological deterioration can be identified by TPR MRI (<0.4), compression ratio (≥50 %), sagittal diameter of ISI (≥50 % of spinal canal diameter). Besides, a history of diabetes is a risk factor for the development of rp-CSM.

Analysis of pathological parameters of cervical spondylotic myelopathy using magnetic resonance imaging.

OBJECTIVES: Cervical spondylotic myelopathy is a cervical degenerative disease that seriously jeopardizes the physical and mental health of patients. The aim of this study was to use magnetic resonance imaging (MRI) to compare differences in pathological parameters among the healthy group, latent cervical spondylosis (LCS) group, and cervical spondylotic myelopathy (CSM) group. PATIENTS AND METHODS: Magnetic resonance imaging (MRI) describes cervical spine changes from the Pavlov ratio of the cervical spinal canal on sagittal T2-weighted images (T2WI), trace value and fractional anisotropy (FA) value of cervical spinal cord on Diffusion tensor images (DTI). In our study, above mentioned parameters were compared among Group A (healthy group), Group B (LCS group) and Group C (CSM group). RESULTS: In Pavlov ratio, there were statistical differences on 7 levels of 10 levels between Group A and B, on all levels between Group C and another two groups. On trace value, there was no statistical difference on all levels between Group A and B. There are statistical differences on 7 levels of 10 levels between Group C and another two groups. On FA value, there was also no statistical difference on all levels between Group A and B. There were statistical differences on 3 levels of 10 levels between Group A and C, on 5 levels of 10 levels between Group B and C. The Pearson correlation between trace value and FA value is -0.526 (p = 0). CONCLUSION: The MRI scan results showed that there was a significant difference among the three groups for the parameter Pavlovian ratio, but not for the parameter trace value and FA value.

The Use of Preoperative and Intraoperative Pavlov Ratio to Predict the Risk of Postoperative C5 Palsy after Expansive Open-Door Laminoplasty for Cervical Myelopathy.

BACKGROUND: No standard preoperative preventive measure has been established to decrease the occurrence of C5 palsy after expansive open-door laminoplasty. The aim of this study is to establish a reliable measured parameter in predicting the risk of the postoperative C5 palsy. MATERIALS AND METHODS: A total of 276 patients receiving posterior open-door laminoplasty for cervical spinal stenotic myelopathy were studied. The patients were divided into two groups according to the preoperative Pavlov ratio (Group A: Pavlov ratio <0.65 and Group B: Pavlov ratio ≥0.65). Correlations between the occurrence of postoperative C5 palsy and Pavlov ratio were analyzed, and Group A was further tested. The surgical procedures, clinical symptoms, and Pavlov ratio were described. RESULTS: The patients with Pavlov ratio <0.65 had a higher risk of developing postoperative C5 palsy (P < 0.05, odds ratio [OR] = 2.91). No significant difference was found in gender, age, etiology, type of operation, and pre- and postoperative Japanese Orthopaedic Association scores between patients with and without postoperative C5 palsy. The cutoff (1.01) of receiver operating characteristic curve of the postoperative Pavlov ratio of the Group A was calculated. The postoperative Pavlov ratio ≥1.01 of the patients in Group A was a significant risk factor of the development of postoperative C5 palsy (P < 0.01, OR = 10.83). CONCLUSIONS: The preoperative Pavlov ratio <0.65 at the C5 level was more likely to develop the postoperative C5 palsy. When the preoperative Pavlov ratio is <0.65, the postoperative Pavlov ratio ≥1.01 at the C5 level is a reliable predictor for the development of postoperative C5 palsy. Pavlov ratio may be one of the reasons for postoperative C5 palsy.

Establishment and verification of a surgical prognostic model for cervical spinal cord injury without radiological abnormality.

Some studies have suggested that early surgical treatment can effectively improve the prognosis of cervical spinal cord injury without radiological abnormality, but no research has focused on the development of a prognostic model of cervical spinal cord injury without radiological abnormality. This retrospective analysis included 43 patients with cervical spinal cord injury without radiological abnormality. Seven potential factors were assessed: age, sex, external force strength causing damage, duration of disease, degree of cervical spinal stenosis, Japanese Orthopaedic Association score, and physiological cervical curvature. A model was established using multiple binary logistic regression analysis. The model was evaluated by concordant profiling and the area under the receiver operating characteristic curve. Bootstrapping was used for internal validation. The prognostic model was as follows: logit(P) = -25.4545 + 21.2576VALUE + 1.2160SCORE - 3.4224TIME, where VALUE refers to the Pavlov ratio indicating the extent of cervical spinal stenosis, SCORE refers to the Japanese Orthopaedic Association score (0-17) after the operation, and TIME refers to the disease duration (from injury to operation). The area under the receiver operating characteristic curve for all patients was 0.8941 (95% confidence interval, 0.7930-0.9952). Three factors assessed in the predictive model were associated with patient outcomes: a great extent of cervical stenosis, a poor preoperative neurological status, and a long disease duration. These three factors could worsen patient outcomes. Moreover, the disease prognosis was considered good when logit(P) ≥ -2.5105. Overall, the model displayed a certain clinical value. This study was approved by the Biomedical Ethics Committee of the Second Affiliated Hospital of Xi'an Jiaotong University, China (approval number: 2018063) on May 8, 2018.

The torg ratio of C3-C7 in African Americans and European Americans: A skeletal study.

The ratio between the sagittal diameter of the spinal canal and the sagittal diameter of the vertebral body, known as the "Torg ratio", is often used to test for spinal canal narrowing. Here, we investigate this ratio in a large population, consisting of two ethnicities, both sexes and three age groups. Measurements were taken on the dry cervical verterbrae (C3-C7) of 277 individuals using a digital apparatus allowing for the recording of 3D coordinates of a set of landmarks on the vertebral body. Vertebral body and vertebral foramen lengths were compared across the different subgroups. Vertebral body and vertebral foramen lengths differ significantly between males and females and between African Americans and European Americans. With age, the vertebral body length increases while the foramen length does not undergo significant changes. These anatomical differences are reflected in differences in the Torg ratio calculated for the different subgroups. In conclusion, our findings suggest that a hard cutoff on the Torg ratio used to define a pathological narrowing of the cervical spine should be adapted to the population the patients come from. Clin. Anat. 32: 84-89, 2019. © 2018 Wiley Periodicals, Inc.

Is cervical disc arthroplasty good for congenital cervical stenosis?

OBJECTIVE Cervical disc arthroplasty (CDA) has been demonstrated to be as safe and effective as anterior cervical discectomy and fusion (ACDF) in the management of 1- and 2-level degenerative disc disease (DDD). However, there has been a lack of data to address the fundamental discrepancy between the two surgeries (CDA vs ACDF), and preservation versus elimination of motion, in the management of cervical myelopathy associated with congenital cervical stenosis (CCS). Although younger patients tend to benefit more from motion preservation, it is uncertain if CCS caused by multilevel DDD can be treated safely with CDA. METHODS Consecutive patients who underwent 3-level anterior cervical discectomy were retrospectively reviewed. Inclusion criteria were age less than 50 years, CCS (Pavlov ratio ≤ 0.82), symptomatic myelopathy correlated with DDD, and stenosis limited to 3 levels of the subaxial cervical (C3-7) spine. Exclusion criteria were ossification of the posterior longitudinal ligament, previous posterior decompression surgery (e.g., laminoplasty or laminectomy), osteoporosis, previous trauma, or other rheumatic diseases that might have caused the cervical myelopathy. All these patients who underwent 3-level discectomy were divided into 2 groups according to the strategies of management: preservation or elimination of motion (the hybrid-CDA group and the ACDF group). The hybrid-CDA group underwent 2-level CDA plus 1-level ACDF, whereas the ACDF group underwent 3-level ACDF. Clinical assessment was measured by the visual analog scales (VAS) for neck and arm pain, Japanese Orthopaedic Association (JOA) scores, and Nurick grades. Radiographic outcomes were measured using dynamic radiographs for evaluation of range of motion (ROM). RESULTS Thirty-seven patients, with a mean (± SD) age of 44.57 ± 5.10 years, were included in the final analysis. There was a male predominance in this series (78.4%, 29 male patients), and the mean follow-up duration was 2.37 ± 1.60 years. There were 20 patients in the hybrid-CDA group, and 17 in the ACDF group. Both groups demonstrated similar clinical improvement at 2 years' follow-up. These patients with 3-level stenosis experienced significant improvement after either type of surgery (hybrid-CDA and ACDF). There were no significant differences between the 2 groups at each of the follow-up visits postoperatively. The preoperative ROM over the operated subaxial levels was similar between both groups (21.9° vs 21.67°; p = 0.94). Postoperatively, the hybrid-CDA group had significantly greater ROM (10.65° vs 2.19°; p < 0.001) than the ACDF group. Complications, adverse events, and reoperations in both groups were similarly low. CONCLUSIONS Hybrid-CDA yielded similar clinical improvement to 3-level ACDF in patients with myelopathy caused by CCS. In this relatively young group of patients, hybrid-CDA demonstrated significantly more ROM than 3-level ACDF without adjacent-segment disease (ASD) at 2 years' follow-up. Therefore, hybrid-CDA appears to be an acceptable option in the management of CCS. The strategy of motion preservation yielded similar improvements of cervical myelopathy to motion elimination (i.e., ACDF) in patients with CCS, while the theoretical benefit of reducing ASD required further validation.

A novel MRI classification system for congenital functional lumbar spinal stenosis predicts the risk for tandem cervical spinal stenosis.

PURPOSE: The purpose of this study was to develop a simple and clinically useful morphological classification system for congenital lumbar spinal stenosis using sagittal MRI, allowing clinicians to recognize patterns of lumbar congenital stenosis quickly and be able to screen these patients for tandem cervical stenosis. METHODS: Forty-four subjects with an MRI of both the cervical and lumbar spine were included. On the lumbar spine MRI, the sagittal canal morphology was classified as one of three types: Type I normal, Type II partially narrow, Type III globally narrow. For the cervical spine, the Torg-Pavlov ratio on X-ray and the cervical spinal canal width on MRI were measured. Kruskal-Wallis analysis was done to determine if there was a relationship between the sagittal morphology of the lumbar spinal canal and the presence of cervical spinal stenosis. RESULTS: Subjects with a type III globally narrow lumbar spinal canal had a significantly lower cervical Torg-Pavlov ratio and smaller cervical spinal canal width than those with a type I normal lumbar spinal canal. CONCLUSION: A type III lumbar spinal canal is a globally narrow canal characterized by a lack of spinal fluid around the conus. This was defined as "functional lumbar spinal stenosis" and is associated with an increased incidence of tandem cervical spinal stenosis.

Correlation of force control with regional spinal DTI in patients with cervical spondylosis without signs of spinal cord injury on conventional MRI.

OBJECTIVES: The aim of this study was to investigate spinal cord structure in patients with cervical spondylosis where conventional MRI fails to reveal spinal cord damage. METHODS: We performed a cross-sectional study of patients with cervical spondylosis without conventional MRI findings of spinal cord damage and healthy controls. Subjects were studied using spinal diffusion tensor imaging (DTI), precision grip and foot force-tracking tasks, and a clinical examination including assessment of neurological signs. A regional analysis of lateral and medial spinal white matter across multiple cervical levels (C1-C5) was performed. RESULTS: DTI revealed reduced fractional anisotropy (FA) and increased radial diffusivity (RD) in the lateral spinal cord at the level of greatest compression (lowest Pavlov ratio) in patients (p < 0.05). Patients with spondylosis had greater error and longer release duration in both grip and foot force-tracking. Similar spinal cord deficits were present in patients without neurological signs. Increased error in grip and foot tracking (low accuracy) correlated with increased RD in the lateral spinal cord at the level of greatest compression (p ≤ 0.01). CONCLUSIONS: Spinal DTI can detect subtle spinal cord damage of functional relevance in cervical spondylosis, even in patients without signs on conventional T2-imaging and without neurological signs. KEY POINTS: DTI reveals spinal cord changes in cervical spondylosis with few symptoms. DTI changes were present despite normal spinal cord on conventional MRI. DTI parameters correlated with force control accuracy in hand and foot. Spinal DTI is a promising technique for patients with cervical spondylosis.

Risk Prediction for Development of Traumatic Cervical Spinal Cord Injury without Spinal Instability.

Study Design Retrospective comparative study. Objective A narrow spinal canal is an important risk factor for predicting a spinal cord injury (SCI); however, the radiologic parameters have not been fully established. The authors conducted a comparative study to forecast SCI risk by determining a predictive spinal canal diameter (SCD) cutoff value from magnetic resonance image (MRI) in the Korean population. Methods On T2-weighted MRI of the cervical spine, the SCD at the pedicle (SCDpedicle) and the intervertebral disk level (SCDdisk) were measured in patients with SCI without spinal instability and in healthy subjects. Additionally, the vertebral body diameter (Dvertebral body) and intervertebral disk diameter (Dintervertebral disk) were measured, and the two ratios (SCDpedicle to Dvertebral body and SCDdisk to Dintervertebral disk) were calculated. In the SCI group, the extent of high signal intensity on the T2-weighted midsagittal MRI was determined. Results The data obtained from 20 patients in the SCI group (18 men, mean age 61.35 years) and 65 individuals in the control group (47 men, mean age 57.05 years) was compared. All the parameters including the SCD and the calculated ratios were significantly smaller in the SCI group than in the control group. Among them, the area under the receiver operating curve (AUC) value for the SCDdisk-to-Dintervertebral disk ratio at C2-C3, with a cutoff ratio value of 0.59, provided the greatest positive predictive value. A low SCDdisk-to-Dintervertebral disk ratio at C4-C5 and the presence of >40 mm of high signal intensity on the MRI were related with the presence of complete SCI. Conclusion Because the C2-C3 level is relatively wide compared with the subaxial cervical spine, a small ratio at C2-C3 provided the greatest positive predictive value in SCI. Complete SCI is associated with a small SCDdisk-to-Dintervertebral disk ratio at C4-C5 and with extensive high signal intensity on MRI.

The diagnostic value of magnetic resonance imaging measurements for assessing cervical spinal canal stenosis.

OBJECT: The authors investigated the relevance of 2D MRI measurements for the diagnosis of critical cervical spinal canal stenosis. Among patients who had sustained a minor cervical spine trauma, they compared MRI measurements of the cervical spine between those with acute cervical spinal cord injury (CSCI) and those without. They also investigated the correlation between the MRI measurements and the severity of CSCI as well as classification accuracy concerning the diagnosis of critical spinal canal stenosis for acute CSCI after a minor trauma. METHODS: The authors conducted a single-center retrospective radiological case-control study of patients who had sustained CSCI after a minor trauma to the cervical spine from January 2000 to August 2010. The controls were patients who had sustained a cervical trauma without clinical or radiological signs of cervical spinal cord pathology. On axial T2-weighted MR images, the following were measured: the transverse spinal canal and cord area, the transverse and sagittal cord diameter, and the sagittal canal diameter of the cervical spine (C3-7). Using these measurements, the authors calculated the cord-canal-area ratio by dividing the transverse cord area by the transverse canal area, the space available for the cord by subtracting the sagittal canal diameter from the sagittal cord diameter, and the compression ratio by dividing the transverse cord diameter by its sagittal diameter. The severity of CSCI was assessed by using the motor index scores of 10 key muscles at different time points (initially, 1, 3, and 12 months after injury) obtained from the clinical records. The intra- and interobserver reliability of the MRI measurements, intra- and intergroup differences, and correlations between variables were also investigated. Receiver operating characteristic curves were calculated for evaluating the classification accuracy of the imaging variables for CSCI. RESULTS: Data for 52 CSCI patients and 77 control patients were analyzed. The intra- and interobserver reliability regarding the MRI measurements ranged from good (0.72) to perfect (0.99). Differences between the CSCI group and the control group were significant (p < 0.001) for all parameters, except for the cord area. The most prominent differences between the groups existed for the spinal canal area, cord-canal-area ratio, and space available for the cord. The classification accuracy was best for the cord-canal-area ratio and the space available for the cord; areas under the curve were 0.99 (95% CI 0.97-1.0) and 0.98 (95% CI 0.95-0.99), respectively. There was no significant (p > 0.05) correlation between any of the imaging parameters and the motor index score at any time point. CONCLUSIONS: The cord-canal-area ratio (> 0.8) or the space available for the cord (< 1.2 mm) measured on MR images can be used to reliably identify patients at risk for acute CSCI after a minor trauma to the cervical spine. However, there does not seem to be any association between spinal canal imaging characteristics and the severity of or recovery from CSCI after a minor trauma.

Reevaluation of the Pavlov ratio in patients with cervical myelopathy.

BACKGROUND: This study was designed to reevaluate the effectiveness of the Pavlov ratio in patients with cervical myelopathy. METHODS: We studied 107 patients who underwent open door laminoplasty for the treatment of cervical myelopathy between the C3 to C7 levels. We determined the Pavlov ratio on preoperative and postoperative cervical spine lateral radiographs, the vertebral body-to-canal ratio on sagittal reconstruction CT scans, and the vertebral body-to-cerebrospinal fluid (CSF) column ratio on T2-weighted sagittal MR images from C3 to C6. The severity of myelopathy was determined using the JOA score on both preoperative and postoperative images. The recovery rate was also calculated. The Pavlov ratio in plain radiographs from patients with myelopathy was compared with the ratio of the vertebral body to the spinal canal on CT and MRI. RESULTS: The average Pavlov ratio between C3 and C6 ranged from 0.71 to 0.76. On CT scan, the average vertebral body-to-canal ratio between C3 and C6 ranged from 0.62 to 0.66. On MRI, the vertebral body-to-CSF column ratio between C3 and C6 ranged between 0.53 and 0.57. A positive correlation was noted between the Pavlov ratio and the vertebral body-to-canal ratio on sagittal-reconstruction CT (correlation coefficient = 0.497-0.627, p = 0.000) and between the Pavlov ratio and the vertebral body-to-CSF column ratio on MRI (correlation coefficient = 0.511-0.649, p = 0.000). CONCLUSIONS: We demonstrated a good correlation between the Pavlov ratio and both the vertebral body-to-canal ratio on CT and the vertebral body-to-CSF column ratio on MRI. Therefore, the Pavlov ratio can be relied upon to predict narrowing of the cervical spinal canal in the sagittal plane.

The relationship between spinal stenosis and neurological outcome in traumatic cervical spine injury: an analysis using Pavlov's ratio, spinal cord area, and spinal canal area.

BACKGROUND: This study examined the relationship between four radiological parameters (Pavlov's ratio, sagittal diameter, spinal cord area, and spinal canal area) in patients with a traumatic cervical spine injury, as well as the correlation between these parameters and the neurological outcome. METHODS: A total of 212 cervical spinal levels in 53 patients with a distractive-extension injury were examined. The following four parameters were measured: Pavlov's ratio on the plain lateral radiographs, the sagittal diameter, the spinal cord area, and the spinal canal area on the MRI scans. The Pearson correlation coefficients between the parameters at each level and between the levels of each parameter were evaluated. The correlation between the radiological parameters and the spinal cord injury status classified into four categories, A (complete), B (incomplete), C (radiculopathy), and D (normal) was assessed. RESULTS: The mean Pavlov's ratio, sagittal diameter, spinal cord area and spinal canal area was 0.84, 12.9 mm, 82.8 mm(2) and 236.8 mm(2), respectively. An examination of the correlation between the radiological spinal stenosis and clinical spinal cord injury revealed an increase in the values of the four radiological parameters from cohorts A to D. Pavlov's ratio was the only parameter showing statistically significant correlation with the clinical status (p = 0.006). CONCLUSIONS: There was a correlation between the underlying spinal stenosis and the development of neurological impairment after a traumatic cervical spine injury. In addition, it is believed that Pavlov's ratio can be used to help determine and predict the neurological outcome.

Reevaluation of the Pavlov Ratio in Patients with Cervical Myelopathy

BACKGROUND: This study was designed to reevaluate the effectiveness of the Pavlov ratio in patients with cervical myelopathy. METHODS: We studied 107 patients who underwent open door laminoplasty for the treatment of cervical myelopathy between the C3 to C7 levels. We determined the Pavlov ratio on preoperative and postoperative cervical spine lateral radiographs, the vertebral body-to-canal ratio on sagittal reconstruction CT scans, and the vertebral body-to-cerebrospinal fluid (CSF) column ratio on T2-weighted sagittal MR images from C3 to C6. The severity of myelopathy was determined using the JOA score on both preoperative and postoperative images. The recovery rate was also calculated. The Pavlov ratio in plain radiographs from patients with myelopathy was compared with the ratio of the vertebral body to the spinal canal on CT and MRI. RESULTS: The average Pavlov ratio between C3 and C6 ranged from 0.71 to 0.76. On CT scan, the average vertebral body-to-canal ratio between C3 and C6 ranged from 0.62 to 0.66. On MRI, the vertebral body-to-CSF column ratio between C3 and C6 ranged between 0.53 and 0.57. A positive correlation was noted between the Pavlov ratio and the vertebral body-to-canal ratio on sagittal-reconstruction CT (correlation coefficient = 0.497-0.627, p = 0.000) and between the Pavlov ratio and the vertebral body-to-CSF column ratio on MRI (correlation coefficient = 0.511-0.649, p = 0.000). CONCLUSIONS: We demonstrated a good correlation between the Pavlov ratio and both the vertebral body-to-canal ratio on CT and the vertebral body-to-CSF column ratio on MRI. Therefore, the Pavlov ratio can be relied upon to predict narrowing of the cervical spinal canal in the sagittal plane.

The Relationship between Spinal Stenosis and Neurological Outcome in Traumatic Cervical Spine Injury: An Analysis using Pavlov's Ratio, Spinal Cord Area, and Spinal Canal Area

BACKGROUND: This study examined the relationship between four radiological parameters (Pavlov's ratio, sagittal diameter, spinal cord area, and spinal canal area) in patients with a traumatic cervical spine injury, as well as the correlation between these parameters and the neurological outcome. METHODS: A total of 212 cervical spinal levels in 53 patients with a distractive-extension injury were examined. The following four parameters were measured: Pavlov's ratio on the plain lateral radiographs, the sagittal diameter, the spinal cord area, and the spinal canal area on the MRI scans. The Pearson correlation coefficients between the parameters at each level and between the levels of each parameter were evaluated. The correlation between the radiological parameters and the spinal cord injury status classified into four categories, A (complete), B (incomplete), C (radiculopathy), and D (normal) was assessed. RESULTS: The mean Pavlov's ratio, sagittal diameter, spinal cord area and spinal canal area was 0.84, 12.9 mm, 82.8 mm2 and 236.8 mm2, respectively. An examination of the correlation between the radiological spinal stenosis and clinical spinal cord injury revealed an increase in the values of the four radiological parameters from cohorts A to D. Pavlov's ratio was the only parameter showing statistically significant correlation with the clinical status (p = 0.006). CONCLUSIONS: There was a correlation between the underlying spinal stenosis and the development of neurological impairment after a traumatic cervical spine injury. In addition, it is believed that Pavlov's ratio can be used to help determine and predict the neurological outcome.

The Significance of Space Available for the Spinal cord at the Injured Level in the Lower Cervical Spine Fractures and Dislocations / 대한정형외과학회잡지

PURPOSE: To evaluate the degree of injury of the spinal cord in relation with the space available for the spinal cord at the level of injury, the sagittal diameter of the spinal canal at the uninjured levels, and the Pavlov ratio at the uninjured levels in fractures and dislocations of the lower cervical spine. MATERIALS AND METHODS: We retrospectively reviewed the records and radiographs of patients who had sustained an acute fracture or dislocation of the cervical spine from 1990 to 1995. We collected patients from Orthopedic and Neurosurgical department of Chonbuk University Hospital and at Orthopedic department of Presbyterian Medical Center. Of the 69 patients analyzed, twelve had no neurological deficit, eleven had an isolated nerve-root injury, twenty-two had an incomplete injury of the spinal cord, and twenty-four had a complete injury. We measured above three parameters from the plain lateral radiographs and assessed the difference by one-way ANOVA and unpaired t-test. RESULTS: 1. The mean space available for the spinal cord at the level of injury was 12.9 millimeter for the complete injury of the spinal cord,13.8 millimeter for the incomplete injury, 14.7 millimeter for an isolated nerve-root injury, and 15.7 millimeter for no neurological deficit group. The overall difference among the groups was significant (F=6.98, P=0.0004). The patients who had a complete injury of the spinal cord and those who had an incomplete injury of the spinal cord were significantly different from the patients who had an isolated nerve-root injury and those who had no neurologic deficit (P=0.002). 2. The mean sagittal diameter of the canal at the proximal and distal uninjured level was 14.3 and 14.6 millimeter for the complete injury of the spinal cord, 14.9 and 14.9 millimeter for the incomplete injury, 15.5 and 16.6 millimeter for an isolated nerve-root injury, and 16.9 and 16.5 millimeter for no neurological deficit group. The patients who had a complete injury of the spinal cord and those who had an incomplete injury of the spinal cord were significantly different from the patients who had an isolated nerve-root injury and those who had no neurologic deficit (P=0.001). 3. The mean Pavlov ratio at the proximal and distal uninjured level was 0.90 and 0.86 for no neurologic deficit group, 0.85 and 0.87 for an isolated nerve-root injury, 0.76 and 0.75 for the incomplete injury of the spinal cord, and 0.76 and 0.76 for the complete injury. The patients who had a complete injury of the spinal cord and those who had an incomplete injury of the spinal cord were significantly different from the patients who had an isolated nerve-root injury and those who had no neurologic deficit (P=0.001). CONCLUSIONS: The patients who sustained a permanent injury of the cord usually had had a narrower sagittal diameter (<14mm) and a lower Pavlov ratio (<0.80) of the spinal canal before injury. Patients who had a large sagittal diameter of the canal may be more likely to be spared a permanent injury of the spinal cord following a fracture or dislocation of the cervical spine compared with patients who have a narrow canal. These findings demonstrated that the severity of the injury of the spinal cord was in part associated with the space available for the cord (at risk:<13mm) after the injury, as measured on plain lateral radiographs.

Pavlov's Ratio of Cervical Spine of Normal Koreans : Determining Spinal Stenosis on Routine Lateral Roentgenograms / 대한정형외과학회잡지

The accepted radiographic method to determine cervical spinal stenosis is the direct measurement of the sagittal diameter of the spinal canal on the routine lateral view of the cervical spine. The reported normal and abnormal values for this measurement are inconsistent because of various methods of obtaining the roentgenograms and different body types which affect the size of the X-ray image. According to Pavlow, the ratio method of determining crevical spinal stenosis, in which the sagittal diameter of the spinal canal is divided by the sagittal diameter of the corresponding vertebral body, is independent of technical factor variables and is a reliable method for determining cervical spinal stenosis. In order to determine the Pavlov's ratio of normal Koreans, and compare it with that of radiculopathic group, we measured the diameter of cervicl canal in 47 normal persons(28 male, 19 female), and 32 patients( 9 male, 23 female) who had transient tingling sensation and radiculopathic symtom from the second to fifth decades. The results were as follows :1) The average Pavlov's ratio from C3 to C7 in normal Korean men are 0.906(0.70–1.13), 0.899 (0.070–1.13),0.948(0.70–1.67) and 0.948(0.67–1.17), respectively, and those of normal Korean women are 0.977(0.83–1.15), 1.021(0.83–1.13), 1.014(0.84–1.33) and 1.055(0.88–1.18), respectively. 2) The average Pavlov's ratio from C3 to C7 in radiculopathic Korean men are 0.88(0.65–1.12), 0.90(0.68–1.12), 0.95(0.79–1.12) and 0.95(0.78–1.06), respectively, and those of radiculopathic Korean women are 0.902(0.70–1.27), 0.905(0.69–1.27), 0.939(0.70–1.33) and 0.931(0.70–1. 18), respectively. 3) There are not statistically differences of the Pavlov's ratio between the control group and the radiculopathic group. 4) We believe that the Pavlov's ratio is an effective method in detection of cervical stenosis and is able to eliminate technical factor such as body position, target and object-to-film distanc.