Exoskeleton Robots Promises Walking and Independence For Paraplegics

A new kind of exoskeleton robot makes the paraplegic patients [patients with paralysis in both the lower limbs] able to stand up and walk.

This has been made possible by a light weight, powerful exoskeleton that enables people with severe spinal cord injuries to stand, walk, sit and climb stairs. The exoskeleton has been developed by team of engineers at Vanderbilt University’s Center for Intelligent Mechatronics.

Parker Hannifin Corporation, a global leader in motion and control technologies has signed an exclusive licensing agreement to develop a commercial version of the device. [Read more...]

Kyphotic Deformity After Laminectomy Spinal Surgery

Spinal deformity after laminectomy occurs in children who undergo this surgery. Laminectomies most often are done in children for spinal cord tumors, neurofibromatosis and syringomyelia.

Kyphosis is the most common deformity that occurs after multiple-level laminectomies though in some cases, scoliosis may be associated.

After multiple level  laminectomy, bony and ligamentous deficiencies, neuromuscular imbalance, progressive deformity, and radiation therapy may cause instability of the spine.

It is postulated that after laminectomy, pressure is increased on the cartilaginous end plates of the vertebral bodies anteriorly, and with time, cartilage growth is decreased and vertebral wedging occurs leading to kyphosis. Radiation therapy has been associated with injury to the vertebral physis and subsequent spinal deformity and may lead to kyphosis as well.

Treatment

As treating the deformity is difficult,it is best to prevent the deformity from occurring if at all possible.

Facet joints should be preserved as far as possible when  laminectomy is necessary. Fusion at the time of facetectomy or laminectomy may help prevent progression of the deformity,

In case of an established deformity which is progressive spinal instrumentation like pedicle screw fixation and spinal fusion may be considered.

 

Degenerative Spondylosis – Presentation, Diagnosis and Treatment

Degenrative spondylolistheis was first described by Rosenberg in 1975. The most commonly affected level is L4-L5 followed bby L3-L4. It may occur at two levels or even three levels simultaneously.

It has also been reported in cervical spine.

Occurrence

Degenerative spondylolisthesis is more common in people over age 50. It is more common in women and blacks.

Cause

Facet joints of the vertebral column restrain the motion of the spine [Allow flexion and extension but restrict rotational movements] while the disc itself acts as shock absorber. With age, as the degeneration sets, the facet joint may not remain competent and allow vertebral body to slip forward on the other. [Read more...]

Normal Canal Dimension In Lumbar Spine

Normal canal dimension in lumbar spine are fairly constant and are given below.

Level

Sagittal (mm)

Coronal (interpedicle) (mm)

L1

16

22

L2

15

22

L3

14

23

L4

13

23

L5

14

 

24

The idea of normal values helps to determine the level of stenosis of the canal.

Developmental Spondylolisthesis – Cause, Diagnosis and Treament

Spondylolisthesis is present in 5% of the population and there is no gender difference in occurrence.

Most spondylolistheses in children and adolescents are developmental.

This type of spondylolisthesis  generally is not noticed until later in childhood or even in adult life.

Etiology and Natural History

Developmntal stenosis needs to be differentiated from acquired traumatic spondylolisthesis caused by stress fracture. Trauamtic sopndylolisthesis following a stress fracture occurs in individuals with no posterior element dysplasia and with normal spino pelvic morphology.

Following conditions are thought to represent a continuum of disease [Read more...]

Sacral Table Angle

The sacral table angle of S1 is the  value of the angle between the superior plate of S1 and the posterior side of body of the first sacral vertebra.

A steeper sacral table [low sacral table angle] indicates a higher sheer stress on L5 to S1 disc resulting in greater tendency for anterior slip.

Pelvic Tilt

Pelvic Tilt is defined angle between the vertical and the line through the midpoint of the sacral plate to femoral heads axis.

Pelvic tilt, sacral slope and pelvic incidence

Pelvic tilt, sacral slope and pelvic incidence

Normal average is 40°.

Overhang defined as the horizontal offset between the midpoint of the sacral plate and the femoral heads axis.

Sum of sacral slope and pelvic tilt gives pelvic incidence.

Image Credit

Sacral Slope

The sacral slope is value of the angle between the superior plate of S1 and a horizontal line.

Measurement of Sacral Slope

Measurement of Sacral Slope

Thus a  vertical sacrum is described by a low value, a horizontal sacrum measures a high value.

Pelvic tilt, sacral slope and pelvic incidence

Pelvic tilt, sacral slope and pelvic incidence

Sum of sacral slope and pelvic tilt gives pelvic incidence.

Image Credit:thejns.org

Pelvic Incidence

Pelvic Incidence is defined as the angle between the line joining the middle of the sacral endplate to the middle axis of the femoral heads.

The pelvic incidence is unique anatomical parameter for each individual and is independent of position or spatial orientation. Pelvic incidence is closely related to Sacral Slope and pelvic tilt [Read more...]

Dysplastic Spondylolisthesis

Dysplastic spondylolisthesis forms the type I spondylolisthesis in Wiltse classification system. It is a true congenital spondylolisthesis that occurs because of malformation of the lumbosacral junction with small, incompetent facet joints.

Dysplastic spondylolisthesis is very rare.

But when it occurs, it is associated with fast progression and severe neurological deficits. [Read more...]