Width of pubic symphysis relating to age and sex in Koreans

Diastasis of the pubic symphysis has been reported to occur in 13-16% of pelvic ring injuries. In Asians, there are only a few data showing the width of the pubic symphysis. The aim of this study is to see the width of pubic symphysis relating to age and sex in Koreans.

Width of pubic symphysis was measured in pelvis AP and pelvic CT of 784 peoples (392 males, 392 females).

In supine AP, the width at the upper end was 4.8±2.5 mm (males; 3.46±1.38 mm, females; 4.04±2.76 mm). The width at the midpoint was 4.7±2.0 mm (males; 4.64±1.58 mm, females; 4.75±2.29 mm). The width at the lower end was 4.8±2.5 mm (males; 4.58±2.19 mm, females; 5.08±2.76 mm). In abducted AP, the width at the upper end was 3.8±2.9 mm (males; 3.65±1.50 mm, females; 3.97±3.85 mm). The width at the midpoint was 4.6±2.3 mm (males; 4.45±2.16 mm, females; 5.18±3.79 mm). The width at the lower end was 4.8±3.1 mm (males; 4.55±1.30 mm, females; 4.74±3.06 mm). In axial CT, the width at the anterior border was 15.0±6.2 mm (males; 14.50±6.62 mm, females; 16.44±6.22 mm). The width at the narrowest point was 3.1±1.5 mm (males; 3.19±1.53 mm, females; 3.09±1.50 mm). The width at the widest point was 4.1±1.6 mm (males; 4.27±1.60 mm, females; 4.00±1.50 mm). The width at the posterior border was 2.3±1.3 mm (males: 2.20±1.30 mm, females; 2.44±1.40 mm). Axial thickness was 27.1±5.3 mm (males; 29.48±4.60 mm, females; 24.70±4.82 mm). In coronal CT, the width at the upper end was 3.1±4.1 mm (males; 2.28±1.26 mm, females; 3.83±5.48 mm). The width at beginning of widening was 3.6±4.5 mm (males; 2.68±1.63 mm, females; 4.54±6.08 mm). The width at the lower end was 20.5±8.2 mm (males; 17.49±4.53 mm, females; 23.60±9.86 mm). Coronal thickness was 20.4±7.1 mm (males; 24.50±5.98 mm, females; 16.23±5.61 mm). In supine film, width significantly increased with age at the upper end (p=0.022) and midpoint (p< 0.001); however, it decreased at the lower end (p< 0.001). In abduction film, width at midpoint increased with age (p=0.003).

Pelvic malunion should be defined according to the population and age. These results could be a reference in assessing the quality of reduction after internal fixation of the patients with traumatic diastasis of the pubic symphysis.