n. (in anatomy) a circular opening or ring-shaped structure. —annular adj.
Rare causes include a tumour in the spine or spinal column, tuberculosis of the spine, ankylosing spondylitis (see SPINE AND SPINAL CORD, DISEASES AND INJURIES OF) or a tumour in one of the organs in the pelvis such as the UTERUS.
Treatment consists essentially of rest in bed in the early stages until the acute phase is over. ANALGESICS, such as aspirin and codeine, are given to relieve the pain. Expert opinion varies as to the desirability of wearing a PLASTER OF PARIS jacket or a specially made corset; also, as to the desirability of manipulation of the spine and operation. Surgeons are selective about which patients might bene?t from a LAMINECTOMY (removal of the protruding disc).... sciatica
The human backbone is about 70 cm (28
inches) in length, and varies little in full-grown people; di?erences in height depend mainly upon the length of the lower limbs. The number of vertebrae is 33 in children, although in adult life ?ve of these fuse together to form the sacrum, and the lowest four unite in the coccyx, so that the number of separate bones is reduced to 26. Of these there are seven in the neck, known as cervical vertebrae; 12 with ribs attached, in the region of the thorax known as thoracic or dorsal vertebrae; ?ve in the loins, called lumbar vertebrae; ?ve fused to form the sacrum; and four joined in the coccyx. These numbers are expressed in a formula thus: C7, D12, L5, S5, Coc4=33.
Although the vertebrae in each of these regions have distinguishing features, all the vertebrae are constructed on the same general plan. Each has a thick, rounded, bony part in front, known as the body, and these bodies form the main thickness of the column. Behind the body of each is a ring of bone, the neural ring, these rings placed one above another forming the bony canal which lodges the spinal cord. From each side of the ring a short process of bone known as the transverse process stands out, and from the back of the ring a larger process, the spinous process, projects. These processes give attachment to the strong ligaments and muscles which unite, support, and bend the column. The spines can be seen or felt beneath the skin of the back lying in the centre of a groove between the muscular masses of the two sides, and they give to the column its name of the spinal column. One of these spines, that of the seventh cervical vertebra, is especially large and forms a distinct bony prominence, where the neck joins the back. Between the bodies of the vertebrae lies a series of thick discs of ?brocartilage known as intervertebral discs. Each disc consists of an outer portion, known as the annulus ?brosus, and an inner core, known as the nucleus pulposus. These 23 discs provide the upper part of the spine with pliability and resilience.
The ?rst and second cervical vertebrae are specially modi?ed. The ?rst vertebra, known as the atlas, is devoid of a body, but has a specially large and strong ring with two hollows upon which the skull rests, thus allowing forward and backward movements (nodding). The second vertebra, known as the axis, has a pivot on its body which ?ts into the ?rst vertebra and thus allows free rotation of the head from side to side. The spinal column has four natural curves (see diagram) which help to cushion the shocks of walking and running.
The neural rings of the vertebrae form a canal, which is wide in the neck, smaller and almost round in the dorsal region, and wide again in the lumbar vertebrae. Down the canal runs the spinal cord, and the nerves leaving the cord do so through openings between the vertebrae which are produced by notches on the upper and lower margins of each ring. The intervertebral foramina formed by these notches are so large in comparison with the nerves passing through them that there is no chance of pressure upon the latter, except in very serious injuries which dislocate and fracture the spine.... spinal column
Kyphosis is a backward curvature of the spine causing a hump back. It may be postural and reversible in obese people and tall adolescent girls who stoop, but it may also be ?xed. Scheuermann’s disease is the term applied to adolescent kyphosis. It is more common in girls. Senile kyphosis occurs in elderly people who probably have osteoporosis (bone weakening) and vertebral collapse.
Disc degeneration is a normal consequence of AGEING. The disc loses its resiliance and becomes unable to withstand pressure. Rupture (prolapse) of the disc may occur with physical stress. The disc between the fourth and ?fth lumbar vertebrae is most commonly involved. The jelly-like central nucleus pulposus is usually pushed out backwards, forcing the annulus ?brosus to put pressure on the nerves as they leave the spinal canal. (See PROLAPSED INTERVERTEBRAL DISC.)
Ankylosing spondylitis is an arthritic disorder of the spine in young adults, mostly men. It is a familial condition which starts with lumbar pain and sti?ness which progresses to involve the whole spine. The discs and ligaments are replaced by ?brous tissue, making the spine rigid. Treatment is physiotherapy and anti-in?ammatory drugs to try to keep the spine supple for as long as possible.
A National Association for Ankylosing Spondylitis has been formed which is open to those with the disease, their families, friends and doctors.
Spondylosis is a term which covers disc degeneration and joint degeneration in the back. OSTEOARTHRITIS is usually implicated. Pain is commonly felt in the neck and lumbar regions and in these areas the joints may become unstable. This may put pressure on the nerves leaving the spinal canal, and in the lumbar region, pain is generally felt in the distribution of the sciatic nerve – down the back of the leg. In the neck the pain may be felt down the arm. Treatment is physiotherapy; often a neck collar or lumbar support helps. Rarely surgery is needed to remove the pressure from the nerves.
Spondylolisthesis means that the spine is shifted forward. This is nearly always in the lower lumbar region and may be familial, or due to degeneration in the joints. Pressure may be put on the cauda equina. The usual complaint is of pain after exercise. Treatment is bed rest in a bad attack with surgery indicated only if there are worrying signs of cord compression.
Spinal stenosis is due to a narrowing of the spinal canal which means that the nerves become squashed together. This causes numbness with pins and needles (paraesthia) in the legs. COMPUTED TOMOGRAPHY and nuclear magnetic resonance imaging scans can show the amount of cord compression. If improving posture does not help, surgical decompression may be needed.
Whiplash injuries occur to the neck, usually as the result of a car accident when the head and neck are thrown backwards and then forwards rapidly. This causes pain and sti?ness in the neck; the arm and shoulder may feel numb. Often a support collar relieves the pain but recovery commonly takes between 18 months to three years.
Transection of the cord occurs usually as a result of trauma when the vertebral column protecting the spinal cord is fractured and becomes unstable. The cord may be concussed or it may have become sheared by the trauma and not recover (transected). Spinal concussion usually recovers after 12 hours. If the cord is transected the patient remains paralysed. (See PARALYSIS.)... spine and spinal cord, diseases and injuries of
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