Idiopathic Scoliosis Progression and Sleep-disordered Breathing in Children

Idiopathic scoliosis (IS) is the most common pediatric musculoskeletal disorder that causes a three-dimensional spinal deformity affecting 2 to 4% of adolescent subjects. It can be progressive (in 3 out of 10 cases) and severe involving serious effects (spine pain, cardiopulmonary compromise, deformed torso, psychosocial issues) and heavy treatments (corset, surgery). However, there is still no reliable criteria to predict the occurrence and progression of IS, while the etiology of IS remains unclear.

Sleep-disordered breathing (SDB) in children is a common condition characterized by recurrent events of upper airway obstruction during sleep. The major symptom is snoring or noisy breathing. Preliminary evidence suggests that SDB in children is associated with low bone mass and postural stability, which might be mechanisms in the development of scoliosis. However, the influence of SDB on the onset or progression of IS remains unknown.

To fill those gaps, investigators will perform a prospective, unrandomized, observational cohort study at a scoliosis center to determine the prevalence and significance of SDB in children with mild-moderate IS. All subjects will be screened with a designated sleep questionnaire (PSQ), and children with either severe daytime sleepiness or frequent snoring or any degree of sleep pause will be requested to undergo further evaluation and an overnight polysomnography (PSG). Routine follow-up visits will be scheduled 6 months apart up to at least 36 months to assess the curve progression of pre-existing scoliosis. At the same time, children with suspected curves but excluded from scoliosis at their first clinic visit will also undergo a sleep evaluation, and be uniformly screened for the new onset scoliosis in Zhejiang Province during 2023-2024. All primary and secondary school students receive annual scoliosis screening led by the Zhejiang provincial government from 2023.

Inclusion criteria

• Diagnosis of idiopathic scoliosis at their first clinic visit
• Skeletally immature (Risser Sign 0-3)
• Cobb angle between 11-40 degrees
• Age between 6 and 15
• Patients can understand and complete the revised Pediatric Sleep Questionnaire at baseline and follow-up visits
• Patients with symptoms suspicious of SDB agree to undergo clinical evaluation and an overnight polysomnogram
• Informed Consent Form signed by subject or the guardian

Exclusion criteria

• Patients with scoliosis other than idiopathic, or with other musculoskeletal or neurodevelopmental conditions that might be responsible for the scoliosis
• History of previous spine surgery or spinal injury
• Tumor or malignant tumor in the spine
• Leg length discrepancy more than 20 mm
• Previous diagnosis or treatment of SDB more than 6 months ago
• Fail to fulfill the questionnaire or refuse to attend any further evaluation
• Severe obstructive sleep apnea syndrome (OSAS) or significant hypoxemia requiring Continuous Positive Airway Pressure treatment
• A guardian who cannot accompany the child on the night of PSG
• Plans to relocate within the next 24 months