Spine
-
Quantitative magnetic resonance imaging (relaxation time and proton density measurements) has gained increasing interest as a noninvasive way to study changes in water content and biochemical composition of lumbar intervertebral discs and vertebral bodies. This article reviews the current methodological problems and the feasibility of quantitative magnetic resonance imaging in the lumbar spine for investigations on water content and biological composition. This technique does not allow direct quantification of water content. Although biochemical variations may sensitively influence relaxation times and proton density under in vitro conditions, it is not feasible to obtain sufficiently reliable and specific information to monitor biochemical alterations associated with lumbar disc pathology in vivo.
-
Mechanical testing of the spine can be carried out in either a load-controlled or a displacement-controlled manner. Each method requires certain assumptions and offers different advantages. ⋯ Thomas Edwards believes that displacement-controlled testing most accurately reflects the in vivo environment, while Drs. Vijay Goel, David Wilder, and Malcolm Pope support the use of the load-controlled method as most logical and easily standardized.
-
This study analyzed anatomic parameters between the midpoint of cervical vertebral lateral masses as seen on the superficial, posterior aspect of the mass and cervical nerve roots. Posterior cervical dissection was performed, with the midpoint of the lateral masses kept intact and the nerve roots exposed. ⋯ This study demonstrates that the posterior midpoint of the lateral mass is a safe point for initiating screw insertion.
-
The purpose of this presentation is to acknowledge the pioneering work of a key historical figure who contributed to the available knowledge in anatomy and biomechanics, developed political and social infrastructure to promote the maturation and standardization of chiropractic education, and influenced a paradigmatic shift away from a monocausal belief in the origin of disease. Literature search and archives retrieval were used. ⋯ Evidence shows that Janse took bold initiatives to influence the chiropractic profession and give it the opportunity to develop as a legitimate healthcare discipline. Janse was a visionary clinical scientist and educator whose 38-year tenure as president of a chiropractic college enabled him to influence the course and development of his profession.
-
Historical Article
Incomplete spondylolysis and healing. A study of ancient Canadian Eskimo skeletons.
Skeletons of ancient Canadian Eskimos subjected to arctic weathering presented an unusual opportunity for direct observation of all stages of spondylolysis. ⋯ Spondylolysis first became recognizable as incomplete stress fractures during adolescence, with most progressing to complete lysis in young adulthood. New fractures continued to develop in young adults, but most healed by middle adulthood. After 45 years of age, the overall frequency of spondylolysis declined, indicating that even complete defects occasionally healed.