Using Radiation-free Ultrasound for Screening Scoliosis Among Female School Children in Hong Kong to Reduce Unnecessary X-ray Exposure

Chinese University of Hong Kong442 enrolled

Overview

In the scoliosis screening program of the Student Health Service (SHS), Department of Health (DH), in Hong Kong, more than 50% of screened school children prescribed with x-ray examination basing on the screening protocol did not have Cobb angle greater than the referral threshold of 20°; ie they did not need specialist referral and thus were subjected to unnecessary x-ray exposure. Our primary objective is to determine whether a new radiation-free ultrasound system could identify subjects with Cobb angle greater than the referral threshold of 20° thus avoiding unnecessary x-rays in the referral workflow. The secondary objective is to evaluate if Angle of Trunk Rotation (ATR) can further increase the accuracy of ultrasound assessment. This study is an extension of the registered project entitled "Using Radiation-free Ultrasound for Screening Scoliosis Among School Children in Hong Kong to Reduce Unnecessary X-ray Exposure", (ClinicalTrials.gov Identifier: NCT03135665), however focusing on validity of ultrasound measurement for immature female subjects aged around ten with year since menarche equal to or less than 9 months, who are prone to curve progression, and thus are among the most critical group in clinical management of scoliosis for regular monitoring, treatment decision, and brace indication.

Study Type

INTERVENTIONAL

Allocation

Purpose

SCREENING

Masking

NONE

Enrollment

442

Conditions

Scoliosis Spinal Curvatures

Interventions

Ultrasound (Scolioscan system), and EOS radiography systemDEVICE

Scolioscan ultrasound system was reported to be reliable and valid for spinal deformity assessment. The system composes of an ultrasound scanner with a linear probe of 10 cm width and frequency range of 4-10MHz, a frame structure and a spatial sensor attached to the ultrasound probe for spatial data capture. Daily calibration will be performed using phantom to assure accuracy of spine image formation and subsequent angle measurement. Subjects will stand on the Scolioscan platform with a standardized posture kept stable with pegs throughout the scanning process. The probe will be steered from L5 to C7 spinous process for scanning. SPA will be used to determine the ultrasound-based Referral Status through predicting whether the Cobb angle is beyond the referral threshold of ≥20° or not. There are two values for the Referral Status: either "for specialist referral" or "not for specialist referral". Coronal Cobb angle measurement on EOS radiographs will be used as gold standard.

Eligibility

Sex: FEMALEMin age: 8 YearsMax age: 14 Years

Medical Language ↔ Plain English

Inclusion Criteria: i. School children in Hong Kong attending School Screening Program provided by Student Health Service ii. Recommended for radiographic assessment in the scoliosis screening program iii. Female with year since menarche of equal to or less than 9 months Exclusion Criteria: i. Patients with standing height \<1 m, or \>2 m ii. Patients with body mass index (BMI) ≥25 kg/m2 iii. Subjects with skin diseases iv. Subjects with fracture or wound that affect ultrasound scanning v. Subjects with ferromagnetic implants vi. Subjects with surgery done for the spine vii. Subjects with winged scapula or other irregularity of back contour that affect ultrasound scanning viii. Subjects who cannot stand steadily during scanning ix. Subjects with allergy to ultrasound gel

Outcomes

Primary Outcomes

ultrasound-based Referral Status

"for specialist referral" or "not for specialist referral", through predicting whether the Cobb angle is beyond the referral threshold of ≥20° or not in scoliosis screening

Time frame: Baseline

Secondary Outcomes

Angle of Trunk Rotation (ATR)

evaluate if this parameter can increase the accuracy of ultrasound assessment