Correlation analysis between digital photography measurement of trunk deformity and self-image perception in patients with idiopathic scoliosis

Abstract

Introduction: It has been suggested that some measures of trunk deformity obtained in digital photography may be useful in the assessment of trunk deformity. The correlations between these measures and radiographic indexes have not been fully analyzed. Study design: Concurrent validity between postural indexes obtained from digital photographs and radiographs. Objective: To assess the validity of a clinical assessment tool of the trunk deformity based on photographs as compared to radiological measurements. Methods: Front and back digital photographs of patients with idiopathic scoliosis (Cobb angle> 25°) were obtained. Shoulder, armpit and waist angles, in addition to trunk asymmetry indexes, were calculated on front and back photographs with Surgimap software. Coronal Cobb angles and clavicle tilt were also calculated on AP radiographs. The Pearson correlation coefficients (r) were used to estimate concurrent validity between both methods. Results: 80 consecutive patients (68 females and 12 males) aged 12 to 40 years old (average 20.3 years old) were included. Mean Cobb angle was 45.9° (range 25.1° to 77.2°). Waist height angle and Cobb angle, both in front and back photographs, were significantly correlated (r = 0.48 back/r = 0.29 front view). The correlation between shoulder and armpit height angles and radiographic clavicle tilt were -0.44 and -0.41 respectively. There was a correlation between right trapezium angle in front view and both Cobb angle (r = -0.22) and clavicle tilt (r = 0.38). No other statistical significant correlations between both methods were found, neither in asymmetry trunk indexes. Conclusion: Digital photography measurement of waist height is useful to assess trunk deformity in idiopathic scoliosis due to a good correlation with Cobb angle. Right trapezium angle can be a clinical measure of shoulder imbalance. Asymmetry trunk indexes are not correlated with radiological measures.