Last update: 25/09/2018, Dr. Miguel B. Royo Salvador, Medical Board number 10389. Neurosurgeon y Neurologist.

What is the Institut Chiari & Siringomielia & Escoliosis de Barcelona’s big news for scoliosis patients?



Scoliosis, or a twisted spine, is a disease that affects 2% of the world population and was first described by Hippocrates 2,400 years ago. The examination and the treatment methods that he explained remain the same until today and nothing has been changed or modified.

Nowadays and according to our published works, scoliosis is a condition that is understood to appear as a consequence of the stretching of the spinal cord by a ligament called filum terminale. This ligament has no function in adults.

scoliosis image 1
scoliosis image 2
scoliosis image 3

Figure 3.- Case 3, patient of 19 with Idiopathic Scoliosis. A. Preoperation X-ray 38º. B. Postoperation, nine months after cutting the filum terminale, 31º. C. Postoperation dorsolumbar MRI, spinal cord goes from an intrathecal cavity to another.
A. Radiografia preoperatoria 38º.
B. Postoperatorio, tras sección del filum terminale a los nueve meses, 31º.
C. RM dorsolumbar preoperatoria, la médula espinal va de una convexidad intrarraquídea a otra.


Does this explanation of Scoliosis have any use for the patients?

Of course, with the simple sectioning of this ligament the strain subjected to the spinal cord is removed which stops the bending stimuli being sent to the vertebral column, hence, the progression of Scoliosis stops.


Does the sectioning of the filum terminale straighten the twisted spine again?

If the human spine had the plasticity and elasticity of a spring or if it was made out of rubber, the vertebral column would return to its normal upright position. But the scoliotic spine is formed under an important bending force acting on bones, joints and ligaments over years. When this force is released, the scoliotic spines’s recovery depends on the degree of its plasticity, which in turn depends on the age, genes and duration and strength of the force that the spine had been subjected to and intensity of the whole process.


Then, what is the purpose of sectioning this ligament?

The first thing that is achieved by sectioning the filum terminale is the elimination of the main traction force that makes the disease progress. Hence, in cases where scoliosis increases very quickly, this progression is majorly stopped.

In some cases, where scoliosis is detected early and after the sectioning of the filum terminale, the vertebral column may spontaneously straighten up a few degrees, and more so if a correct pattern of neuro-rehabilitation is followed.

If the scoliosis is however detected late and at very advanced stage, despite suppressing the bending force of the filum terminale, the very same spinal imbalance becomes another bending force, which would require intense neuro-rehabilitation, with corset or surgical action for spinal fixation. In any case, the sectioning of the filum terminale is recommended to influence different therapeutic actions positively and minimize the risk posed to the spinal cord from getting stretched further during the use of bracing and surgical procedures to correct the spine.


What is the surgical sectioning of the filum terminale?

The surgical sectioning of the filum terminale consists of making a small opening at the sacrum bone, at the end of the spine, without involving any inconveniences that could alter the mechanics of the spine. The Filum terminale ligament is exposed and sectioned with microsurgical techniques, all in just half an hour and it has the added bonus of required hospitalization of less than a day.


What are the consecuences of cutting this ligament?

The filum terminale, is the result of an empty cover of the spinal cord found at the lower end of the back or lumbosacral region. In the human embryo, the vertebral column and the spinal cord inside have the same length and are separated by some membranas named dura mater, arachnoid and piamater. With the individual’s normal growth, the vertebral column grows about 20 cm more than the spinal cord. The layers that separate the spinal cord from the vertebral column in the lower back region do not contain spinal cord anymore and fold in the form of fibrous cord which is the filum terminale. This sliding of the spinal cord could be compared to a sock we are wearing it and we pull it out half way off our foot, the half that does not contain the foot could be cut at any point with no harm to the foot. In the same way, the filum terminale can be cut along its way without suffering any consequences. (1, 2)


Is the surgery useful in all cases of scoliosis?

The sectioning of the filum terminale is applicable only in cases of scoliosis that are of idiopathic nature, of unknown cause, and does not apply to other types such as degenerative, neoplastic, cancerous, post paralysis and other (3).


Does the traction force acting on the spinal cord have any effect on the brain?

The tension of the filum terminale, besides causing a bending stimulus to the spine in order to avoid the strain of the spinal cord, also causes the descent of the lower part of the brain, the cerebellar tonsils, through the foramen magnum (the foramen magnum connects the skull with the spine) causing the Arnold-Chiari I syndrome, a disease that was described 100 years ago and so far was of unknown cause.

The surgical sectioning of the filum in the Arnold-Chiari I syndrome takes away the tension acting downwards on the cerebellar tonsils. It stops them from suffering self-strangulation in the foramen magnum. In this way it results in the improvements in many symptoms related to this disease, whilst the cerebellar tonsils usually do not ascend because of deformation and their low elasticity.


Does the spinal cord suffer damage with the stretching?

It has been proven with studies conducted in animals that slight traction acting on the spinal cord makes the neurons stop functioning due to a lack of adequate blood circulation.

In humans, this traction, when it is intense, makes the blood circulation decrease in the centre of the spinal cord, especially in the cervical region, when it reaches the maximum slide. In this zone important arteries of the spinal cord are present and there is a special distribution of spinal arteries and are centripetal in nature i.e. they go from the outside towards the centre. The lack of blood circulation results in the necrosis of a part of spinal cord tissue, which in turn draws interstitial fluid and intramedullary cyst is formed in the centre of the spinal cord called Syringomyelia, a disease described 500 years ago, so far it was of unknown cause.


Does this mean that also other disease can be treated with the same surgical procedure as scoliosis?

Just in Scoliosis, in Syringomyelia, the sectioning of the Filum stops the progression of the disease. The cyst, which is a result of dead nerve cells, remains the as it is, but it may disappear when the space surrounding the spinal cord spontaneously opens, or when it does the same towards the centre, where there is a canal called the ependymal canal which connects the centre of the spinal cord with the brain cavities (ventricles). The symptoms of the disease are caused by the dead cells and the tumorous effect of the cyst. The sectioning of the filum terminale has two beneficial effects: it stops the cell death due to cord traction and reduces the tumorous effect of the cyst as the spinal cord relaxes.


Has this treatment been applied in patients?

We have operated patients with idiopathic scoliosis, also in cases with an association with Arnold Chiari I Syndrome and / or syringomyelia. It has stopped the evolution of the disease and spectacular improvements have been achieved in some cases, especially in the cases where the curvature of the spine was of less than 40 degrees.


Can you give an example?

You can find patients cases in the testimonials section: Scoliosis.


Images: Before and after of the sectioning of the Filum Terminale

– Case N. 17584


Scoliosis case 2014

Scoliosis case 2015


Case N. 17253









Example of a Scoliogram or X-ray of the whole vertebral column


Escoliograma de frente

Scoliogram done frontwards

Escoliograma de perfil

Scoliogram done sideways


Pathologies and definitons regarding the Filum Disease

For more information on the concept of the Filum Disease, please see:

Involved Diseases



  1. Dr. Miguel B. Royo Salvador (1996), Siringomielia, escoliosis y malformación de Arnold-Chiari idiopáticas, etiología común (PDF). REV NEUROL (Barc); 24 (132): 937-959.
  2. Dr. Miguel B. Royo Salvador (1996), Platibasia, impresión basilar, retroceso odontoideo y kinking del tronco cerebral, etiología común con la siringomielia, escoliosis y malformación de Arnold-Chiari idiopáticas (PDF). REV NEUROL (Barc); 24 (134): 1241-1250
  3. Dr. Miguel B. Royo Salvador (1997), Nuevo tratamiento quirúrgico para la siringomielia, la escoliosis, la malformación de Arnold-Chiari, el kinking del tronco cerebral, el retroceso odontoideo, la impresión basilar y la platibasia idiopáticas (PDF). REV NEUROL; 25 (140): 523-530
  4. M. B. Royo-Salvador, J. Solé-Llenas, J. M. Doménech, and R. González-Adrio, (2005) “Results of the section of the filum terminale in 20 patients with syringomyelia, scoliosis and Chiari malformation“.(PDF). Acta Neurochir (Wien) 147: 515–523.
  5. M. B. Royo-Salvador (1992), “Aportación a la etiología de la siringomielia“, Tesis doctoral (PDF). Universidad Autónoma de Barcelona.
  6. M. B. Royo-Salvador (2014), “Filum System® Bibliography” (PDF).
  7. M. B. Royo-Salvador (2014), “Filum System® Guía Breve”.


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