Age- and sex-related variations in sagittal sacropelvic morphology and balance in asymptomatic adults

Abstract

Introduction Many studies suggest the importance of the sagittal sacropelvic balance and morphology in spinal and hip disorders. This study describes the normal age-and sex-related changes in sacropelvic morphology and balance in a prospective cohort of asymptomatic adults without spinal disorder. Materials and methods A prospective cohort of 709 asymptomatic adults without spinal pathology was recruited. There were 354 males and 355 females aged 37.9 ± 14.7 and 35.7 ± 13.9 years, respectively. For each subjects, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured from standing lateral radiographs. Ratios of SS to PI (SS/PI), PT to PI (PT/PI), and PT to SS (PT/SS) were also calculated. Results There was no significant difference in PI (pelvic incidence), SS (sacral slope), PT (pelvic tilt), PT/PI, SS/PI, or PT/SS between males and females. The mean ± 2 standard deviations (SD) range was 32°-74°, 0°-27°, and 24°-55°for PI, PT and SS, respectively. The mean ± 2 SD range was greater than 0.5 for SS/PI and less than 0.5 for PT/PI. PI was not related to age in either sex group. PT, SS, PT/PI, SS/PI, and PT/SS presented only weak correlation coefficients (r B 0.21) with respect to age. Conclusion The current study presents the largest cohort of asymptomatic adults in the literature dedicated to the evaluation of sagittal sacropelvic morphology and balance. The range of values corresponding to the mean ± 2 SD can provide invaluable information to clinicians about the normal range of values expected in 95% of the normal population.

Spinopelvic balance: new biomechanical insights with clinical implications for Parkinson’s disease

“…In particular way, these two parameters, but not TK, presented a moderate negative correlation with the years from the diagnosis. Furthermore, in contrast with previously reported data [5,24], the lack of correlation with age indicates that the modification of these sagittal balance parameters likely represents a typical pathological adaptation of the spine to the disease. The positive correlation existing among LL, SSA, SPA and ST indicates, anyway, that the preservation of LL is of paramount importance to avoid a progressive sagittal imbalance and pain [10,12,14,23,24], as seen in the aging process [24] and in other kind of spinal diseases [2,3,6,12,13].…”

“…We know from the scientific literature that for healthy individuals the PT value is less than half of the PI value, while the SS is more than half the value of PI [1,4,5]. In the studied group of PD patients, PT/PI ratio and SS/PI are on the average \0.5 and over 0.5, respectively, which is in agreement with previously reported data [4].…”

“…have not yet been defined at present; nevertheless, when compared to healthy adult cohorts reported in the literature [4,5,13,24], although the anatomical parameter PI is similar, the functional PT appears increased and SS decreased. The suggested normality value of 0.5 for the PT/ PI ratio [1,10] is overcome by five patients (16.1 %).…”

“…1). As described by Mac-Thiong et al [5] the relationships between the parameters of sacropelvic balance and morphology have been studied calculating the following ratios SS to PI (SS/PI), PT to PI (PT/PI), PT to SS (PT/SS) ( Table 1). This set-up of radiographic parameters has been used to stage the evolution of spinal imbalance severity in different patients (Fig.…”

“…Today, the importance of sagittal plane alignment for the treatment of spinal disorders is widely recognized in the scientific world [1][2][3][4][5][6]. The understanding of the regulatory principles of sagittal balance is useful to achieve good outcomes when treating different spinal disorders in the field of orthopedic rehabilitation and spine surgery, especially when treating major deformities [3,7,8].…”