Influence of age on pelvic inlet and outlet radiographic views

Abstract

The aim of the study was to assess the relationship of patients' age to the angles of X-ray inlet and outlet pelvis views to fixation of sacral fractures with cannulated screws. Material and methodsTo conduct the study, CT data were analyzed in 106 patients with posterior pelvic injuries requiring fixation with cannulated screws. Sagittal reconstructions of preoperative computed tomography were used, and the angles of the true inlet, super-inlet, pelvic opening, sacral concavity, promontory angle, pelvic outlet S1, pelvic outlet S2 were constructed and measured. The statistical correlation of the angle of inclination of the sacrum depending on age is estimated.ResultsA two-stage cluster analysis divided the patient population into two groups with significant differences in pelvic opening angles and age (N1 = 64, N2 = 42). Statistically significant differences were found between the two clusters in all the studied parameters: median angles of true pelvic inlet 27.2° [23.2°-32.2°] and 18.2 [11.4-26.6], respectively, (p0.001); super-pelvic inlet 42.5 [39.3-47.8] and 36.2 [28.7-42.8] respectively, (p0.001); The correlation between age and pelvic angle is inverse, statistically significant (p=0.534; p0.001).ConclusionAs a result of the analysis, it was revealed that with an increase in the patient's age by 1 year, the opening angle of the pelvis decreases by 0.26 degrees. If the angle of the true inlet is equal to or less than 14.95 degrees, it should be expected that it is difficult to visualize the projection of the outlet S1 and S2 during the operation. The median angle difference before and after correction of the anterior slope of the sacrum by placing a roller under the coccyx was 9.4° with an interquartile range from 7.8° to 11°. Among the patients included in the study, significant anatomical differences in the structure of the posterior pelvis ring were revealed.