Spondylolisthesis
(spon-dee-low-lis-thee-sis)
 Forward slippage of the 5th
lumbar vertebra |
The word spondylolisthesis derives
from - spondylo which means spine, and listhesis which means slippage.
Although the word itself is somewhat of a
tongue-twister, a spondylolisthesis is simply a forward slip of one vertebra relative to
another.
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Anatomy
The spine consists of a series of
vertebrae held together to give support for the spinal cord and nerves arising from it.
Each vertebra consists of a solid body with a bony ring behind it. At the top and bottom
of this ring are bony protuberances called articular processes which articulate (form a
working joint) with the neighbouring vertebrae.
These articulations form the facet joints that provide
stability to the spine.
Spondylolysis
(spon-dee-low-lye-sis)
Before a spondylolisthesis can develop
there must be a spondylolysis present.
In spondylolysis there is a defect in the pars
interarticularis (which literally means the "piece between the
articulations").
So spondylolysis means a defect in the
thin piece of bone connecting the upper and lower facets, and can be unilateral (involving
one side) or bilateral (involving both sides). Although the defect can be found at any
level, the commonest vertebra involved is the 5th Lumbar vertebra (or L5).
In cases of bilateral spondylolysis, the
posterior articulations can no longer provide the posterior stability, and anterior
slipping of the L5 vertebra over the sacrum could result. This slip itself is called
Spondylolisthesis.
Diagnosis
A routine lateral (below) radiograph taken while standing confirms a
diagnosis of a spondylolisthesis. The x-ray will show the translation
(slip) of one vertebra over the adjacent level, usually the one below.
Using the lateral (side) x-ray, the
slip is graded according to its degree of severity. The Myerding grading
system measures the percentage of vertebral slip forward over the body
beneath. The grades are as follows:
Grade 1: 25%
Grade 2: 25% to 49%
Grade 3: 50% to 74%
Grade 4: 75% to 99%
Grade 5: 100%*
*Complete vertebral slippage, known
as spondyloptosis.
What causes it?
The commonest cause of spondylolisthesis
is spondylolysis, however, the cause of spondylolysis is the subject of much debate.
Some experts feel that it is an inherited defect of the pars
interarticularis. In surveys of school children, spondylolysis is present in 4% to 6%
of cases even when the child has no symptoms.
Among the Eskimos, the incidence is as
high as 40%, perhaps suggesting a genetic factor. Conversely, it has been postulated that
the high prevalence of pars defects in the Alaskan Eskimos could be due to carrying
infants in a papoose which places an undue amount of premature stress on the pars
interarticularis. This keeps the infant in an upright position for extended periods of
time and these devices may cause their children to develop pars defects.
Closer to home parents should avoid the
use of an upright walker until the child can walk unassisted as overloading bones not yet
strong enough to take the weight of the body may cause pars fractures.
However, certain other observations point
to repetitive trauma causation. Incidence goes up with age, and incidence is higher in
children involved in certain kinds of sports like gymnastics, weight-lifting and football
that put a lot of stress on the back.
In gymnastics, the hyperextension position
of the lumbar spine places excessive stress on the back, leading to stress fractures in
the pars interarticularis.
 In an
attempt to unify the two causative theories, some physicians believe that most children
with spondylolysis may be born with a "weak" pars interarticularis.
Repeated stress with activities during the years of growth between 8 and 14 causes the
"stress fracture" that leads on the spondylolysis.
The red
arrows show the pars fracture in this 15 year old male basketball player
Symptoms that often accompany
spondylolisthesis:
Pain in the low back,
especially after exercise
Increased lordosis (i.e., swayback)
Pain and/or weakness in one
or both thighs or legs
Reduced ability to control bowel
and bladder functions
Tight hamstring musculature
In cases of advanced spondylolisthesis
changes may occur in the way people stand and walk such as the development of a waddling
style of walking. This causes the abdomen to protrude further, due to the low back curving
forward more. The torso (chest, etc.) may seem shorter; and muscle spasms in the low back
may occur.
Spondylolisthesis typical posture may
include:
Short torso (body)
Flat buttocks
Rib cage appears low
Iliac crests (hip bones) are
high
Altered gait because of tight
hamstrings
Vertical sacrum
Hips don't fully extend back
However, most children with spondylolysis,
and even some children with spondylolisthesis may not experience back pain and may grow up
unaware that they have the condition.
For those with symptoms, back pain is
probably the most common symptom, and often presents during the adolescent growth spurt.
There is often a history of trauma at sports, usually trivial, and an X-ray reveals the
"fracture". In adolescents, boys are affected 2 to 3 times more often than
girls. However, at times the spondylolysis is not due to that particular injury, but a
result of years of cumulative stress of the back.
Sometimes the child is brought in by the
parents because of poor posture or funny gait. This is usually due to spondylolisthesis,
causing muscle spasm in the back that makes the back stiff, and tight hamstrings causing
the child to walk with the knees bent, and a short stride. Sometimes, there is an
associated scoliosis that is more obvious to the observer than the spondylolisthesis.
The two x-ray images show a
spondylolysis in a 16 year old footballer in the picture above left, and a spondylolysis
in a 14 year old hockey player on the right.
How do you prevent it?
There is nothing you can do about your
genes, but there is certainly something you can do about your activities.
Avoiding sports in the growing years is
usually not an option, but you can choose your sports wisely. For your little gymnast,
limiting the number of hours of practice (unless she is an aspiring Olympian), or
alternating gymnastics with another sport like swimming or bicycling may be helpful. And
there is no place for weight lifting in the pre-pubertal child.
Sportspeople with a higher risk of
spondylolysis/spondylolisthesis include: 
Gymnasts
Divers
Pole vaulters
Weight lifters
Wrestlers
Dancers
High jumpers
Adult spondylolisthesis
In adults, spondylolisthesis is usually
caused by degenerative disk disease and often affects women over 40 years of age.
Degenerative disc on the left, normal
healthy disc on the right
With aging, discs lose water content and ultimately
height. As the vertebra on either side of the disc come closer to each other through the
loss of disc height, the upper vertebra may slide forward on the sub-adjacent vertebra
producing spondylolisthesis.
Spondylolisthesis is also associated with
deterioration of the facet joints connecting the two vertebrae. As the facet joints become
arthritic due to this deterioration, they enlarge in an attempt to confer stability. As
the two rings of the vertebral segments which make up the spinal canal, slide past each
other, the canal narrows in size. The combination of canal narrowing and enlargement of
the facet joints, produces the characteristic nerve compression problems found in
degenerative spondylolisthesis. The nerves are compressed in two major areas at the site
of a degenerative spondylolisthesis. It is believed that a reduction in nerve blood flow
accounts for the symptoms produced from spinal canal narrowing.
The role of chiropractic
Specialised advanced chiropractic
treatments for Spondylolysis and Spondylolisthesis have been developed over the years and
have great success in both relieving symptoms and providing greater stability. At the
Holdfast Bay Musculoskeletal Centre we utilise the Cox mechanised flexion-distraction
technique in treating these problems. The treatment is very gentle, quite pleasant to
undergo, and brings pleasing results.
The role of rehabilitation
It is important that individual patient
weaknesses are assessed and that a program is prepared which is specific to their needs.
The goals of exercise are to improve back and abdominal strength and increase flexibility.
Since tight hamstrings are almost always part of the clinical picture, appropriate
hamstring stretching is important. Instruction in pelvic tilt exercises may help reduce
any postural component causing increased lumbar lordosis. Myofascial release may play a
role as well in reducing pain from the soft tissue component.
Surgery
Surgery becomes necessary only if all of
the above treatments fail to keep the patient relatively free of pain, or at least keep it
at a tolerable level. Surgical treatment for Spondylolysis and Spondylolisthesis must
address both the mechanical symptoms and the compressive symptoms if they are present and
when indicated can be quite successful.
click below see
video.
 
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