Biomedical subjects

John France

Publications and source records attributed to John France.

3 recordsLinked to original sources

PubMed2006

Interobserver and intraobserver reliability of maximum canal compromise and spinal cord compression for evaluation of acute traumatic cervical spinal cord injury.

STUDY DESIGN: Prospective, blinded validation study of an objective, quantitative measure to assess maximum canal compromise (MCC) and maximum spinal cord compression (MSCC) in individuals with acute cervical spinal cord injury (SCI). OBJECTIVE: To examine the intraobserver and interobserver reliability of MCC and MSCC in individuals with acute traumatic cervical SCI. SUMMARY OF BACKGROUND DATA: To date, few quantitative reliable radiologic methods for assessing the extent of spinal cord compression in the setting of acute SCI have been reported. MCC and MSCC, as assessed on mid-sagittal CT and T2-weighted MR images, respectively, appear to have potential clinical and prognostic value. To date, the validation of these assessment tools has been limited to a small number of observers at a single institution. However, to date no study has focused on the reliability of these radiologic parameters among a large cohort of spine surgeons from North America and abroad. This type of validation is critical to allow the broader use of these outcome measures in research studies and in clinical practice. METHODS: Mid-sagittal MRI and CT images of cervical spine were selected from 10 individuals with acute traumatic cervical SCI. A total of 28 spine surgeons independently estimated CT MCC, T1-weighted MRI MCC, and T2-weighted MRI MSCC on two occasions using a calibrated ruler. In the first round of measurements, the observers estimated the radiologic parameters using only written instructions. The second measurement set was obtained after an interactive teaching session on the methodology. The order of the images was altered for the second set of measurements. RESULTS: Analysis using parametric and nonparametric statistics indicated high intraobserver reliability for CT MCC, T1-weighted MRI MCC, and T2-weighted MSCC with interclass correlation coefficients (ICCs) of 0.92, 0.95, and 0.97, respectively. The interobserver reliability for all three radiologic parameters was considered moderate with ICCs ranging from 0.35 to 0.56. CONCLUSION: Our results indicate that the intraobserver reliability for the MCC and MSCC was high. Although the interobserver reliability for all three radiologic parameters in the present study was below 0.75, the observed differences were small and largely accounted for by the limitations in the precision of the calibrated ruler. For cases with minimal cord compression, the measurement of canal stenosis (MCC) proved more accurate. In contrast, in cases with severe cord compression, the assessment of MSCC was more accurate. It is anticipated that the use of digital imaging technologies will further enhance the precision of these outcome measures.

Acute Disease↗

PubMed2006

Radiographic measurement parameters in thoracolumbar fractures: a systematic review and consensus statement of the spine trauma study group.

STUDY DESIGN: Systematic review. OBJECTIVES: To review the various radiographic parameters currently used to assess traumatic thoracolumbar injuries, emphasizing the validity and technique behind each one, to formulate evidence-based guidelines for a standardized radiographic method of assessment of these fractures. SUMMARY OF BACKGROUND DATA: The treatment of thoracolumbar fractures is guided by various radiographic measurement parameters. Unfortunately, for each group of parameters, there has usually been more than 1 proposed measurement technique, thus creating confusion when gathering data and reporting outcomes. Ultimately, this effect results in clinical decisions being based on nonstandardized, nonvalidated outcome measures. METHODS: Computerized bibliographic databases were searched up to January 2004 using key words and Medical Subject Headings on thoracolumbar spine trauma, radiographic parameters, and methodologic terms. Using strict inclusion criteria, 2 independent reviewers conducted study selection, data abstraction, and methodologic quality assessment. RESULTS: There were 18 original articles that ultimately constituted the basis for the review. Of radiographic measurement parameters, 3 major groups were identified, depicting the properties of the injured spinal column: sagittal alignment, vertebral body compression, and spinal canal dimensions, with 14 radiographic parameters reported to assess these properties. CONCLUSIONS: Based on a systematic review of the literature and expert opinion from an experienced group of spine trauma surgeons, it is recommended that the following radiographic parameters should be used routinely to assess thoracolumbar fractures: the Cobb angle, to assess sagittal alignment; vertebral body translation percentage, to express traumatic anterolisthesis; anterior vertebral body compression percentage, to assess vertebral body compression, the sagittal-to-transverse canal diameter ratio, and canal total cross-sectional area (measured or calculated); and the percent canal occlusion, to assess canal dimensions.

Consensus↗

PubMed2005

Helical computed tomography alone compared with plain radiographs with adjunct computed tomography to evaluate the cervical spine after high-energy trauma.

BACKGROUND: Current literature supports the use of the three-view plain-radiograph series supplemented, when necessary, with helical computed tomography to evaluate the cervical spine in patients who have sustained trauma injury. The purpose of this study was to determine if helical computed tomography alone can be used to evaluate the cervical spine for acute osseous injury following high-energy trauma, thus eliminating the need to make radiographs. METHODS: Patients were prospectively evaluated with helical computed tomography scanning of the cervical spine and standard three-view plain radiography. At a later date, the plain radiographs and computed tomography scans were independently reviewed by two radiologists who were blinded to both the initial interpretation and the interpretation of the corresponding study. The radiologists documented whether the plain radiographs were adequate and whether they showed an acute process. The findings in the study were compared with the initial findings and, when necessary, with the discharge summaries to determine if an injury had been identified. The accuracy of the plain radiographs, of the plain radiographs that had been deemed adequate, and of helical computed tomography used alone was ascertained. RESULTS: Plain radiographs and helical computed tomography scans were made for 407 patients, and traumatic injuries were identified in fifty-eight of them. Plain radiographs alone were adequate for 194 (48%) of the 407 patients. Plain radiographs had a sensitivity of 45%, a specificity of 97%, a positive predictive value of 74%, and a negative predictive value of 91%. Adequate plain radiographs had a sensitivity of 52%, a specificity of 98%, a positive predictive value of 81%, and a negative predictive value of 93%. Helical computed tomography had a sensitivity and specificity of 98%, a positive predictive value of 89%, and a negative predictive value of >99%. The sensitivity, positive predictive value, and negative predictive value of adequate plain radiographs differed significantly from those of helical computed tomography alone (p < 0.001). Twelve (48%) of twenty-five adequate plain radiographs of patients in whom an injury had been identified on computed tomography missed that injury. Helical computed tomography alone missed one (2%) of the fifty-eight injuries. CONCLUSIONS: Although helical computed tomography has a limited ability to detect pure ligamentous injury, it can be safely used without plain radiographs to evaluate the cervical spine for osseous abnormalities such as fractures and dislocations after high-energy trauma.

Adolescent↗