LONG-TERM EFFECT OF SELECTIVE THORACIC FUSION ON LUMBAR DEGENERATIVE DISC DISEASE IN IDIOPATHIC SCOLIOSIS

Scoliosis is the most common deformity of the spine affecting approximately
2-3% of children
younger than 16 years of age4. In 0.3-0.5% of the children, the spinal curve
becomes progressive
and requires treatment. It is a complex three-dimensional deformity of the
spine that presents
during childhood, and usually worsens during adolescence. It is ten times more
common in female
than in males. The most common scoliosis is the idiopathic scoliosis which
means there is no
definite etiology. The curve can cause pain, shortness of breath and fatigue on
young age. Most
children with scoliosis do not have complaints of the deformity. The treatment
of the
asymptomatic adolescent scoliosis patients aims to prevent future problems,
like osteoarthritis of
the spine and degenerative disc disease. The goal of the treatment is a curve
with a angle of less
than 45 degree at skeletal maturity. Natural history studies indicate that
curves bigger than 45
degree tend to progress after skeletal maturity due to gravity. If curves
become larger, the more
the spine is out of his equilibrium, which cause an asymmetric force on spinal
joints en discs.
Besides osteoarthritis of the spine, major curves can cause nerve, heart, lungs
and psychological
problems.
Treatment of idiopathic scoliosis attempts alter the natural history of the
disease. The only proven
conservative treatment is brace treatment. Children have to were the brace
during a few years of
their growth spurt 20 hours a day and is only effective in rapidly growing
immature patients with a
mild spinal curvature (25-45 degrees). Severe curves over 45 degrees are an
indication of surgical
treatment. Surgical treatment does not completely cure scoliosis, but helps to
correct the curve by
approximately 50% and manage curve progression by fusing a large area of the
spine to prevent
further progression. The aim of the brace is to stop progression and maintain
the curve below 45
degrees thereby leaving the patient with a deformity with lesser risk of
problems in later life. A
recent randomized controlled trial confirmed the efficacy of bracing in
idiopathic scoliosis with
level-1 evidence by showing a significant reduction of curve progression and
subsequent reduction
of the need for surgery.
Despite treatment in adolescence, few patients experience problems during
adolescence.
Treatment of the asymptomatic adolescent scoliosis patients aims to prevent
future problems.
Many adult scoliosis patients experience back pain caused by osteoarthritis and
degenerative disc
disease4. Backpain and poor self-image due to the cosmetic deformity can result
in social and
psychological problems. Although scoliosis treatment is focused on long-term
problems, only few
scoliosis studies have studied the long term outcomes of current surgical and
non-surgical
treatments. There is evidence that surgery of the primary curve may have a
short term protective
effect on the unfused discs below the fusion area, possibly because they are
more symmetrically
loaded after surgery than before5,6. However it will stiffens a part of the
spine. Because of the long
fused thoracic segment, more load is centered on the lumbar segment of the
spine in spinal
movements, which may cause increased stress on zygapophysial joints and
intervertebral discs. This
may cause progression of degenerative osteoarthritis en degenerative disc
disease.
Furthermore, last year we examined the influence of the thoracic curve on the
pulmonary function
in patients with scoliosis. A meta-regression analysis showed that pulmonary
function (FEV1 and
FVC) in children and adolescents decreases with 1% per 2.5 to 3 degrees
increase of the Cobb
angle. Information on the long-term outcomes of the influence of scoliosis on
pulmonary function
is scarse, therefor we would like to re-do the spirometry to compare the
outcomes with the
spirometry during childhood.

Our overall aim of the our project is to evaluate the long-term treatment
effects of bracing and
surgery in patients with adolescent idiopathic scoliosis, with a minimum 25
years follow-up.
Secondly, to determine clinical and/or radiological predictors to predict curve
progression.
1) What is the prevalence and degree of osteoarthritis and degenerative disc
disease in the lumbar
spine using radiographical imaging (i.d. Radiography and MRI)?
2) Is there a relation between these radiological findings and long-term
clinical outcomes (e.g.
backpain, quality of life) in these patient group?

The study is cross-sectional cohort study and enrolls scoliosis and control
patients. It will be
performed at the department of Orthopedics of the OLVG in Amsterdam. Patients
meeting the
inclusion and exclusion criteria will be selected from the OLVG scoliosis
database. Patients will be
contacted by telephone. After providing them with information on the study,
patients will be asked
if they are willing to participate after 2 weeks of consideration time. If a
patient gives approval, a
patient information letter and an informed consent form will be send to them.
After completing the
informed consent, the X-ray of their full spine and MRI scan of their lumbar
spine will be scheduled.
After the scan, the patients will be contacted by phone to discuss the outcome
of their scans.
In accordance with our research protocol, we will inquire whether patients have
undergone spinal radiography within the past five years prior to obtaining a
new radiograph. In the event that such a radiograph exists, we will seek
consent to retrieve and utilize these images for our research purposes,
particularly in cases where the radiograph was conducted at a different medical
facility.

For the study, the patient have to come once to the hospital. During this visit
two X-rays and one
MRI of the lower back will be taken. Thereby, a spirometry will be performed.

The patient*s burden from the study consists of one extra visits of 2,5 hours
to the OLVG hospital. It involves a standard anterior-posterior & lateral
radiographs and an MRI scan of the lumbar spine. The patient*s burden from the
study consists of one visit to the OLVG hospital. After analyzing the images,
the patients will be contacted by phone to discuss the outcome of their scans.
The questionnaires are already completed as part of a previous BASIS study in
OLVG hospital.
There are no risks associated with the MRI scan of the lumbar spine.
The risk of the single upright AP and lateral radiograph of the lumbar spine
will be limited. The effective radiation dose for a AP Lower Back image is 680
µSv.32 The additional annual radiation dose is limited if the natural annual
exposure of 2 mSv is considered and will do the patient no harm.33 The
International Commission on Radiological Protection categorizes the
corresponding level of risk qualitative due to radiation as *low* with a
quantitative risk of about 1 in 10.000 or less.
Radiation safety measures, such as using appropriate lead shielding and
minimizing the number of X-ray images taken, are employed to keep the radiation
dose as low as reasonably achievable (ALARA principle). Additionally,
healthcare providers follow specific protocols and equipment standards to
ensure that radiation doses are within safe limits.
Overall, a single X-ray of the spine in the AP and Sagittal views is generally
considered to be safe and compliant with Dutch laws and regulations on medical
radiation exposure. As with any medical procedure, healthcare providers
prioritize patient safety and ensure that radiation doses are kept as low as
reasonably achievable while providing valuable diagnostic insights

The risk associated with a MRI (Magnetic Resonance Imaging) scan of the lumbar
spine is generally considered to be very low. MRI uses a powerful magnetic
field and radio waves to create detailed images of the internal structures of
the body, including the spine. Unlike other imaging techniques that use
ionizing radiation (such as X-rays or CT scans), MRI does not expose the
patient to ionizing radiation, which is a significant advantage in terms of
safety. There are some considerations to keep in mind:
- Claustrophobia: Some individuals may experience claustrophobia (fear of
enclosed spaces) while inside the MRI machine, which can lead to discomfort or
anxiety during the procedure.
- Metallic objects: MRI uses a strong magnetic field, and therefore, it is
essential to remove all metallic objects from the body, including jewelry,
watches, and certain medical implants or devices, as they can be attracted to
the magnet or cause interference with the scan.