Lumbar Spinal Motion Analysis

This dissertation, "Lumbar Spinal Motion Analysis" by Wai-ning, Kris, Wong, 黃偉寧, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Lumbar spinal motion analysis Abstract of thesis entitled "Lumbar spinal motion analysis" submitted by Kris Wai Ning WONG for the degree of Doctor of Philosophy at The University of Hong Kong in May 2006 Summary of background Data. Spinal "instability" is a common clinical condition but difficult to diagnose. It has been suggested to involve a characteristic change in the relationship between vertebrae during motion. Assessment of lumbar "instability" using functional radiographs is controversial. Intervertebral motion analysis using videofluoroscopic images is useful in making diagnosis on lumbar motion disorders. Several approaches have been used to detect the landmarks from medical image but usually require heavy human intervention in refining the features. Objectives We aimed to develop and validate a new method for the automatic continuous assessment of lumbar spinal motion using the digital videofluoroscopy and advancement of computer technology. 1Lumbar spinal motion analysis Methods A lumbar spinal motion analysis system was developed and the reliability of that was assessed. The developed system in assessing the dynamic lumbar motion requires less human intervention by automating the edge detection and snake fitting. Operators need to set up initial snake position in the first frame only. The edge will be detected and the snake will fit toward the edge accordingly. This greatly reduces the effort of physicians in setting accurate landmarks of vertebra manually in every video frame. The reduction in human intervention implies reduction in error rate due to fatigue of the operator. 100 healthy volunteers and 96 patients with diagnosis of degenerative spondylolisthesis were recruited. Dynamic segmental motion were captured and analyzed in every frame intervals during flexion/extension. Intervertebral flexion/extension (IVFE) of each vertebral level was calculated. Results In normal subjects, the lumbar vertebrae flexed with a descending order from L1 to L5 throughout the motion. Conversely, the concavity of lumbar lordosis increased steadily in extension. A linear-liked motion pattern was found in different genders and age groups in various vertebral levels. No statistically significant difference in the pattern of motion was found between genders. However, statistically significant increases in the slopes of IVFE curves were found in age group 51 or above. In patients groups, four distinguished segmental mobility patterns namely hyper-mobile, normal, hypo-mobile and total immobile groups were noted. The slippage level in hyper-mobile group was found to take up the major segmental movement of the total 2Lumbar spinal motion analysis anatomical motion in forward flexion. In hypo-mobile group, the IVFE of slippage level was found to be less compared to normal group. Total immobility of the slippage level was also found in some patients throughout the total flexion range of motion, while the motion was shared by the above or below motion segments. Age and degree of slippage are the major predictors of the different mobility patterns. Conclusions A precise clinical diagnosis of spinal motion disorder can be made with the new image analysis system. With high accessibility of the videofluoroscopy unit and digital video image recorder in most of clinical settings, the new image analysis system may have a