Mobile Device-based 3D Scanning Accurately Captures Deformity in Adolescent Idiopathic Scoliosis

Background: Screening and diagnosis in adolescent idiopathic scoliosis (AIS) currently relies on in-person clinical and edit radiographic examination. White-light 3D scanning (WL3D) can generate high quality 3D representations of surface anatomy using a mobile device. We hypothesized that WL3D would provide accurate deformity assessments compared to scoliometer and radiographic measurements.

Methods: Patients 10 to 18 years old being evaluated or managed for AIS, with a scoliosis radiograph within 30 days of clinic presentation and no edit history of spinal surgery were enrolled. 3D scans were taken in the upright and forward bend positions. Image processing software was used to make 3D measurements of trunk shift (TS), coronal balance (CB), and clavicle angle (CL) in upright position and largest angle of trunk rotation (ATR) as detected in the lumbar and thoracic spine in bending position. 3D trunk shift, coronal balance, clavicle angle were compared to their analogous radiographic measurements. 3D ATR and ATR as measured by a scoliometer (SM) were correlated to major curve magnitude (CM).

Results: Sixty-three patients were included. Mean coronal major curve magnitude was 33.1°. Correlations between the edit TS, CB, and CL radiographic and 3D measurements were 0.95, 0.85, and 0.71 respectively (Figure 1). Correlations between CM and 3D ATR were 0.7 overall (0.73 in the thoracic spine, and 0.66 in the lumbar spine, Figure 2). Correlations between CA and SM were 0.64 overall (0.73 in the thoracic spine, and 0.38 in the lumbar spine). A univariate model demonstrated that major curve magnitude was more accurately predicted as a function of the 3D ATR (p < 0.01) vs scoliometer measurement (p = 0.154).

Conclusion: Portable 3D scanning identifies clinically relevant scoliotic deformity and is more predictive of radiographic Cobb angle than scoliometer examination. This new modality can facilitate scoliosis screening and monitoring perhaps decreasing the need for in-person clinic visits or radiation exposure.