Scottie dog sign is a radiological sign which refers to the appearance of lumbar spine in oblique view X-ray. [1] In the X-ray, the spine can be visualised as the lateral view of a Scottie dog, [2] with the pedicle as the eye, the transverse process as the nose, the superior articular facet as the ear and the inferior articular facet as the front leg, spinous process as the body. It was once used as a diagnostic sign for lumbar spondylolysis, but it is not commonly in use nowadays because of the advent of more sensitive diagnostic methods such as the CT scan and MRI scan. [3]
A computed tomography scan is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists.
The lumbar vertebrae are, in human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process and by the absence of facets on the sides of the body. They are designated L1 to L5, starting at the top. The lumbar vertebrae help support the weight of the body, and permit movement.
In anatomy, the axis is the second cervical vertebra (C2) of the spine, immediately inferior to the atlas, upon which the head rests.
Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and compresses the nerves and blood vessels at the level of the lumbar vertebrae. Spinal stenosis may also affect the cervical or thoracic region, in which case it is known as cervical spinal stenosis or thoracic spinal stenosis. Lumbar spinal stenosis can cause pain in the low back or buttocks, abnormal sensations, and the absence of sensation (numbness) in the legs, thighs, feet, or buttocks, or loss of bladder and bowel control.
Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated discs, and fractured vertebrae. The lumbar spine is often the site of back pain. The area is susceptible because of its flexibility and the amount of body weight it regularly bears. It is estimated that low-back pain may affect as much as 80 to 90 percent of the general population in the United States.
Spondylosis is the degeneration of the vertebral column from any cause. In the more narrow sense it refers to spinal osteoarthritis, the age-related degeneration of the spinal column, which is the most common cause of spondylosis. The degenerative process in osteoarthritis chiefly affects the vertebral bodies, the neural foramina and the facet joints. If severe, it may cause pressure on the spinal cord or nerve roots with subsequent sensory or motor disturbances, such as pain, paresthesia, imbalance, and muscle weakness in the limbs.
Degenerative disc disease (DDD) is a medical condition typically brought on by the normal aging process in which there are anatomic changes and possibly a loss of function of one or more intervertebral discs of the spine. DDD can take place with or without symptoms, but is typically identified once symptoms arise. The root cause is thought to be loss of soluble proteins within the fluid contained in the disc with resultant reduction of the oncotic pressure, which in turn causes loss of fluid volume. Normal downward forces cause the affected disc to lose height, and the distance between vertebrae is reduced. The anulus fibrosus, the tough outer layers of a disc, also weakens. This loss of height causes laxity of the longitudinal ligaments, which may allow anterior, posterior, or lateral shifting of the vertebral bodies, causing facet joint malalignment and arthritis; scoliosis; cervical hyperlordosis; thoracic hyperkyphosis; lumbar hyperlordosis; narrowing of the space available for the spinal tract within the vertebra ; or narrowing of the space through which a spinal nerve exits with resultant inflammation and impingement of a spinal nerve, causing a radiculopathy.
Spondylolisthesis is the displacement of one spinal vertebra compared to another. While some medical dictionaries define spondylolisthesis specifically as the forward or anterior displacement of a vertebra over the vertebra inferior to it, it is often defined in medical textbooks as displacement in any direction. Spondylolisthesis is graded based upon the degree of slippage of one vertebral body relative to the subsequent adjacent vertebral body. Spondylolisthesis is classified as one of the six major etiologies: degenerative, traumatic, dysplastic, isthmic, pathologic, or post-surgical. Spondylolisthesis most commonly occurs in the lumbar spine, primarily at the L5-S1 level, with the L5 vertebral body anteriorly translating over the S1 vertebral body.
Myelography is a type of radiographic examination that uses a contrast medium to detect pathology of the spinal cord, including the location of a spinal cord injury, cysts, and tumors. Historically the procedure involved the injection of a radiocontrast agent into the cervical or lumbar spine, followed by several X-ray projections. Today, myelography has largely been replaced by the use of MRI scans, although the technique is still sometimes used under certain circumstances – though now usually in conjunction with CT rather than X-ray projections.
Congenital vertebral anomalies are a collection of malformations of the spine. Most, around 85%, are not clinically significant, but they can cause compression of the spinal cord by deforming the vertebral canal or causing instability. This condition occurs in the womb. Congenital vertebral anomalies include alterations of the shape and number of vertebrae.
Spondylolysis is a defect or stress fracture in the pars interarticularis of the vertebral arch. The vast majority of cases occur in the lower lumbar vertebrae (L5), but spondylolysis may also occur in the cervical vertebrae.
A spinal disc herniation is an injury to the cushioning and connective tissue between vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical disability. The most conclusive diagnostic tool for disc herniation is MRI, and treatment may range from painkillers to surgery. Protection from disc herniation is best provided by core strength and an awareness of body mechanics including posture.
The facet joints are a set of synovial, plane joints between the articular processes of two adjacent vertebrae. There are two facet joints in each spinal motion segment and each facet joint is innervated by the recurrent meningeal nerves.
The pars interarticularis, or pars for short, is the part of a vertebra located between the inferior and superior articular processes of the facet joint.
A calcaneal fracture is a break of the calcaneus. Symptoms may include pain, bruising, trouble walking, and deformity of the heel. It may be associated with breaks of the hip or back.
A compression fracture is a collapse of a vertebra. It may be due to trauma or due to a weakening of the vertebra. This weakening is seen in patients with osteoporosis or osteogenesis imperfecta, lytic lesions from metastatic or primary tumors, or infection. In healthy patients, it is most often seen in individuals suffering extreme vertical shocks, such as ejecting from an ejection seat. Seen in lateral views in plain x-ray films, compression fractures of the spine characteristically appear as wedge deformities, with greater loss of height anteriorly than posteriorly and intact pedicles in the anteroposterior view.
A Chance fracture is a type of vertebral fracture that results from excessive flexion of the spine. Symptoms may include abdominal bruising, or less commonly paralysis of the legs. In around half of cases there is an associated abdominal injury such as a splenic rupture, small bowel injury, pancreatic injury, or mesenteric tear. Injury to the bowel may not be apparent on the first day.
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual in onset and improve with leaning forward. Severe symptoms may include loss of bladder control, loss of bowel control, or sexual dysfunction.
The vertebral column, also known as the backbone or spine, is the core part of the axial skeleton in vertebrate animals. The vertebral column is the defining characteristic of vertebrate endoskeleton in which the notochord found in all chordates has been replaced by a segmented series of mineralized irregular bones called vertebrae, separated by fibrocartilaginous intervertebral discs. The dorsal portion of the vertebral column houses the spinal canal, a cavity formed by alignment of the neural arches that encloses and protects the spinal cord.
Each vertebra is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species.