VertebraThe spinal column, a defining synapomorphy shared by nearly all vertebrates, is a moderately flexible series of vertebrae (: vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the backbone), and on the other with phylogenetic differences among the vertebrate taxa.
KyphosisKyphosis is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. Abnormal inward concave lordotic curving of the cervical and lumbar regions of the spine is called lordosis. It can result from degenerative disc disease; developmental abnormalities, most commonly Scheuermann's disease; Copenhagen disease, osteoporosis with compression fractures of the vertebra; multiple myeloma; or trauma.
Spinal fusionSpinal fusion, also called spondylodesis or spondylosyndesis, is a neurosurgical or orthopedic surgical technique that joins two or more vertebrae. This procedure can be performed at any level in the spine (cervical, thoracic, lumbar, or sacral) and prevents any movement between the fused vertebrae. There are many types of spinal fusion and each technique involves using bone grafting—either from the patient (autograft), donor (allograft), or artificial bone substitutes—to help the bones heal together.
LordosisLordosis is historically defined as an abnormal inward curvature of the lumbar spine. However, the terms lordosis and lordotic are also used to refer to the normal inward curvature of the lumbar and cervical regions of the human spine. Similarly, kyphosis historically refers to abnormal convex curvature of the spine. The normal outward (convex) curvature in the thoracic and sacral regions is also termed kyphosis or kyphotic. The term comes from the Greek lordōsis, from lordos ("bent backward").