Entretien avec le Docteur Cotrel
Kyphosis, lordosis, scoliosis...
Question
Kyphosis, lordosis, scoliosis… All these notions are not always so clear in one’s mind.
Dr Cotrel would you mind clarifying them?
Answer
First of all, I believe it is important to remind a few anatomy notions :
The human spine is made of 24 mobile vertebrae, piled on top of each other. They form the spinal column.
Front-view, and for all bipeds, this spine rises/stands vertically, on an horizontal “platform” called: sacrum. Together with the iliac bones, they form the pelvic belt on which the two thighbones are joint.
Back-view, the vertebrae fit into each other and are linked by articulatory process of vertebra, acting like hooks, preventing the vertebrae to slip on one another. They surround and protect the spine. They are held and linked together by ligaments.
Front-view, one can see roughly cylindrical thick bones which dimension grows from top to bottom. It is called body of vertebrae and it forms a supporting column : it is stable, strong and mobile.
The bodies of vertebrae are separated and reunited by discs, made of a fibrous and elastic annulus. A pulpous nucleus is « trapped » between the discs, it behaves like an inserted marble, enabling the slanting of the vertebrae and acting as a shock absorber and pressure distributor.
Sideways, due to the oblique departure from the sacrum, the man’s spine presents curvatures of different directions. Curvatures with backward convexity are called kyphosis. Those with frontward convexity are called lordosis.
From top to bottom, there are (see opposite picture):
- cervical lordosis (1),
- dorsal kyphosis (2),
- lumbar lordosis (3).
They are physiological and secure the antero-posterior balance of the trunk. The increase of either curvature, or of several at the same time and beyond a certain limit can be caused by a disease. In that case, the curvature is pathological.
Front-view, the spine is absolutely straight. The shoulders, thorax, waist as the line of the back – when bending - are symmetrical.
All lateral deviations of the spine are called scoliosis.
All scoliosis cause/bring an asymmetry of the trunk. This is noticeable at the level of the neck, shoulders plates and waist, when standing.
Scoliosis is not as disease as such, it is a symptom which may have many causes.
Are there different types of scoliosis?
There are many of them. Should one only refer to a dictionary’s definition, a scoliosis is a lateral deformity of the spine.
It is essential distinguish functional scoliosis from structural scoliosis. Only these latter are pathological.
Functional scoliosis are lateral slanting of the spine with no deformity of the vertebrae.
Most of the time, there are temporary and their evolution during the growth period is benign. They disappear when the person is laying. For instance, it could be a scoliosis due to an inequality between the lower limbs. It can be corrected with special built-up shoes.
It can also be a case of « attitude scoliosis », due to a negative pose at school or at work. Or else, it could be a case of a unilateral muscular contraction. All these vanish as soon as their cause disappears.
All structural scoliosis are lateral deviation of the spine with deformities of its global component, vertebrae and intervertebral discs. They continue when the person lays.
This deviation exists and develops in the 3 dimensional spaces, which implies an absolute torsion of the spine.
In the transversal plane, it will generate a lateral inflexion.
In the sagittal plane, it will reduce or reverse the physiological dorsal and lumbar curves.
In the, horizontal plane, at the top of the curve, the vertebras will rotate on their axis – their anterior part turns towards convexity, their posterior part turns towards concavity.
In this rotatory movement, the dorsal vertebra draws along the ribs which fastened/tied on the sides, moving them forward on the concave side, and backwards on the convex side. The lateral inflexion along with the dorsal kyphosis setting/reduction, the spinal torsion and the spinal compression provoke a tri-dimensional thoracic deformity which could incur dramatic respiratory failures.
The vertebral rotation will manifests itself with a highly significative sign for a diagnosis of structural scoliosis : a lateral hunch, called thoracic hump, on the convex side.
It clearly shows when a person bends forwards, with straight legs and hands at the same level, and that one looks at the silhouette from the back.
This is a sign all mothers should know and regularly look for.
What is idiopathic scoliosis?
Summary expected soon
How will the scoliosis evolve?
content available soon
Today, what is the available treatment?
Summary expected soon
Is idiopathic scoliosis still a vast research field?
Yes indeed.
There are still many areas to be explored. So many questions remain unanswered !
- What is the cause or what are the causes for idiopathic scoliosis?
- Why is it more prevalent in girls than in boys?
- What determines where it occurs?
- Why are some idiopathic scoliosis more progressive than others?
- What is the mechanism of their progression, is it linked to vertebrae, discs or ligaments?
- Could there be any other unknown anomalies linked to the disease?
- What is the role of the standing position inherent to human beings in its appearance and its progression? Do centres of balance play a role?
- In the broad senseof what we call idiopathic scoliosis, could there be other diseases of unknown origins?
- How can we manage to define their individual characteristics? How can patients benefit from a better treatment? How can these scoliosis be prevented?
All these questions were already asked some 50 years ago and there are still unanswered today !
It seems that a genetic factor exists. The frequency of familial cases is highly significant. A study conducted in 1972 showed that in at least 40% of cases, another case within the patients’ family was found. This shows the importance of systematic early examinations carried out on all siblings of a child suffering from idiopathic scoliosis.
Endocrinological, biomechanical, neurologic and metabolic factors may also have an effect in the appearance and the aggravation of the disease.
The responsible factors have still not yet been identified.
What role do each of these factors have in the progression of the disease? Are they related and do they combine?
And if so, how?
How can the Foundation be active in spinal research?
Summary expected soon