Measurement of Clavicular Symmetry in Healthy Subjects Using Tomographic Database of Public Hospitals

Abstract

Objective This study aimed to perform an imaging evaluation to prove the existence or not of symmetry between the clavicles of healthy subjects from Curitiba, Paraná, Brazil, and identify potential factors influencing the clavicular length. Method The study analyzed chest computed tomography (CT) scans of 211 patients with no clavicular fracture or malformations (100 women and 111 men). We measured the greatest clavicular diagonal on both sides, and the software automatically generated the maximum distance in millimeters. Relative and absolute frequencies described qualitative variables and mean values; quantitative variables used a 95% confidence interval. Value comparisons employed the student's t-test, and correlations determinations used Pearson's correlation coefficient. The significance level adopted was 5%. Results There was a significant difference between the clavicular length (right clavicle, 143.58 mm; left clavicle, 145.72 mm; p = 0.037), indicating asymmetry. On average, the left clavicle was 3.71 mm larger. Asymmetry was significant for both men and women (p < 0.001). The average difference was 4.13 mm for men and 3.23 mm for women. Seventy-three percent of the sample had < 5 mm of asymmetry, 23.7% had 5 to 10 mm, and 3.3% had > 10 mm of asymmetry. Conclusion The studied population did not present clavicular symmetry. On average, the left clavicle was longer than the right clavicle, with differences of 3.71 mm in the general sample, 3.23 mm in women, and 4.13 mm in men. The only significant factor was gender since men presented longer clavicles and higher differences than women.

Keywords: anatomy, regional; anthropometry; clavicle; tomography.

Fig. 1

Demonstration of the DICOM Arya/PACS Aurora software (©Pixeon, 2022) and the method for clavicular length measuring with the '3D Ruler' tool. The upper panel identifies the midpoint of the joint face of the clavicle to the acromioclavicular joint (Point 1). The lower panel shows the midpoint of the joint face of the clavicle to the sternoclavicular joint (Point 2).

Fig. 2

Boxplot demonstrating the variation of clavicular measurements regarding the right or left side, indicating a greater length of the left clavicle compared with the contralateral one.

Fig. 3

Boxplot showing the range of clavicular measurements per gender, indicating longer clavicles in males than females and a longer left clavicle compared with the right clavicle.

Fig. 4

The scatterplot shows data dispersion indicating the lack of association between age and clavicular length.

Fig. 5

The distribution of observed and predicted values reveals a good model adjustment.

Fig. 1

Demonstração do software DICOM Arya / PACS Aurora (©Pixeon, 2022) utilizado e do método de aferição do comprimento clavicular com a ferramenta ‘Régua 3D’. No quadro superior, identificado o ponto médio da face articular da clavícula em relação à articulação acromioclavicular (Ponto 1) e no quadro inferior identificado o ponto médio da face articular da clavícula em relação à articulação esterno-clavicular (Ponto 2).

Fig. 2

Boxplot demonstrando a variação das medidas claviculares tendo como referência o lado direito ou esquerdo, indicando um maior comprimento da clavícula esquerda em comparação à contralateral.

Fig. 3

Boxplot demonstrando a variação das medidas claviculares tendo como referência o sexo, indicando os maiores comprimentos claviculares para o sexo masculino em comparação ao feminino e a manutenção da clavícula esquerda com maiores dimensões em comparação à direita.

Fig. 4

Scatterplot evidenciando a dispersão dos dados que indica a não-associação entre idade e comprimento clavicular.

Fig. 5

Distribuição dos valores observados e preditos indicando bom ajuste do modelo realizado .