|Year : 2017 | Volume
| Issue : 2 | Page : 132-136
A study of sagittal pelvic diameters and their variations with advancing age in Gujarati female population by reformatted computed tomography
Ritesh K Shah1, Jalpa N Desai1, Ajay R Upadhyay2, Bharat G Patel1
1 Department of Anatomy, GCS Medical College, Ahmedabad, Gujarat, India
2 Department of Radiodiagnosis, GCS Medical College, Ahmedabad, Gujarat, India
|Date of Web Publication||4-Jun-2018|
Dr. Jalpa N Desai
A-62, Ashok Tenament, Opp. Cadila Lab, Ghodasar - 380 050, Ahmedabad, Gujarat
Source of Support: None, Conflict of Interest: None
CONTEXT: Pelvic diameters are found to be race and age dependent. Gradual horizontalization of sacrum with the advancement of age causes changes in the sagittal pelvic diameters.
AIMS: The aim of the present study is to derive values of sagittal pelvic diameters in Gujarati females, analyze these data to find out changes with regard to the age, and compare the same with other studies.
SETTINGS AND DESIGN: This was an observational, retrospective study.
MATERIALS AND METHODS: A total of 100 stored abdominopelvic computed tomography (CT) scan images were used for the present study. Pelvic parameters were analyzed on reformatted three-dimensional CT images. Sagittal diameters of inlets including anatomical, obstetric, and diagonal conjugate and at level of the pelvic cavity and pelvic outlet were measured.
STATISTICAL ANALYSIS USED: Medcalc version 14 was used for statistical analysis. Data were compared and analyzed to determine the significance of difference between the two age groups.
RESULTS: Mean ± standard deviation of anatomical conjugate was 11.07 ± 1.12 cm, obstetric conjugate was 11.00 ± 1.13 cm, diagonal conjugate was 12.04 ± 1.05 cm, pelvic cavity was 11.53 ± 0.86 cm, outlet at the level of lower end of sacrum was 10.56 ± 0.82 cm, and outlet at the level of tip of coccyx was 8.97 ± 0.99 cm. These parameters analyzed with regard to the age showed that the sagittal diameters at level of inlet decrease with increasing age and at level of cavity and outlet increase with increasing age.
CONCLUSIONS: The present study concluded that various sagittal pelvic diameters vary in different races and populations. All the sagittal pelvic diameters show changes with increase in age, but changes in pelvic inlet diameters are found to be more significant.
Keywords: Age-related changes, pelvimetry, reformatted three-dimensional computed tomography scan
|How to cite this article:|
Shah RK, Desai JN, Upadhyay AR, Patel BG. A study of sagittal pelvic diameters and their variations with advancing age in Gujarati female population by reformatted computed tomography. J Exp Clin Anat 2017;16:132-6
|How to cite this URL:|
Shah RK, Desai JN, Upadhyay AR, Patel BG. A study of sagittal pelvic diameters and their variations with advancing age in Gujarati female population by reformatted computed tomography. J Exp Clin Anat [serial online] 2017 [cited 2018 Jun 24];16:132-6. Available from: http://www.jecajournal.org/text.asp?2017/16/2/132/233676
| Introduction|| |
Pelvimetry is the measurement of dimensions of the bony pelvis. The term pelvis is applied vaguely to the skeletal ring formed by the hip bones, sacrum, coccyx, and the cavity therein. The pelvis can be regarded as having greater and lesser segments or the true and false pelvis (Mahadevan, 2008).
The measurements of various diameters of the pelvis at the level of pelvic inlet, cavity, and outlet were found to vary in different races or populations. These measurements have been analyzed by many anatomists, anthropologists, obstetricians, and radiologists in attempts to understand the type of pelvis, especially in females (Mahadevan, 2008). Studies also show that the pelvic bone system changes with age mostly due to vertical posture affecting the dimensions of the lesser pelvis (Peleg et al., 2007; Oksana, 2014; Vazquez-Barragan et al., 2016).
The pelvic bony measurements are sometimes made in the clinical practice using X-ray, computed tomography (CT) scan, and magnetic resonance imaging (MRI) (Mahadevan, 2008). CT's ability to capture high-level details of bony features makes it an ideal tool to save time and to protect remains from physical manipulation (Decker et al., 2011). The aim of the present study was to find out the different values of various sagittal pelvic diameters in Gujarati female population, compare the same with other populations as well as find out if there is any relationship of these parameters with age.
| Materials and Methods|| |
Computed tomography data
It is an observational, retrospective study using the stored CT image in the Department of Radiology database of the patients who needed the image study for other purposes. A sample size (with prior calculation) of 100 female abdominopelvic CT images with age above 20 years were analyzed in the study. Any CT image showing pelvic fracture, pelvic bony malformation, and pelvic bone tumor – primary and secondary neoplasm – were excluded from the study.
Measurements of each pelvis were obtained from three-dimensional CT-reformatted images that extracted only bone data. For each CT, the following morphometric evaluations were performed:
- Anatomical conjugate diameter (ACD): Distance between the center of the sacral promontory and the upper border of the pubic symphysis [Figure 1]
- Obstetric conjugate diameter (OCD): Distance between the center of the sacral promontory and the most prominent point on posterior surface of the pubic symphysis [Figure 1]
- Diagonal conjugate diameter (DCD): Distance between the center of the sacral promontory and the lower border of the pubic symphysis [Figure 1]
- Anteroposterior diameter of pelvis cavity: Distance between the midpoints of disc between S2 and S3 vertebrae and posterior surface of the pubic symphysis [Figure 1]
- Pelvic outlet 1: Distance between the lower end of sacrum and lower end of the pubic symphysis [Figure 1]
- Pelvic outlet 2: Distance between the tip of the coccyx and lower end of the pubic symphysis [Figure 1].
|Figure 1: Image of the pelvis by reformatted three-dimensional computed tomography scan showing sagittal pelvic measurements. Anatomical conjugate diameter (1), obstetric conjugate diameter (2), diagonal conjugate diameter (3), sagittal pelvic cavity diameter (4), sagittal pelvic outlet 1 diameter (5), and sagittal pelvic outlet 2 diameter (6)|
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Statistical analysis was obtained using the computer program Medcalc version 14. The means and standard deviation for each measurement were determined for all the samples as well as for each group. Two-tailed Student's t-test was used to determine the significance of differences between the two age groups (P < 0.05). All derived results were plotted and included in tables.
This study was approved by the Institutional Ethics Committee of GCS Medical College, Hospital and Research Centre with the registration code ECR/339/Inst/GJ/2013/RR-16. There were no financial or commercial gains in the completion of this study. The authors declare no conflict of interest.
| Results|| |
In the present study, 100 CT scans of Gujarati Indian females were analyzed and means for different diameters were calculated and are presented in [Table 1].
|Table 1: Morphometric data of all pelvic diameters of 100 Gujarati females|
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Samples were divided into two groups on grounds of age for the study purpose. Group A (n = 50) included those cases between 20 and 40 years of age and Group B (n = 50) included those with age above 40 years. The mean for each diameter in both the groups was derived and presented in [Table 2]. Result of a statistical analysis demonstrates that pelvic diameter is age dependent, which is represented by a regression line [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]. As presented in [Table 2], with increasing age, the mean diameters of inlet decrease [Figure 2], [Figure 3], [Figure 4] and the same for pelvic cavity and outlet increase [Figure 5], [Figure 6], [Figure 7].
|Table 2: Morphometric results of the pelvic diameters classified by age group|
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|Figure 2: Age-related changes of the sagittal diameter of the lesser pelvis (ACD)|
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|Figure 3: Age-related changes of the sagittal diameter of the lesser pelvis (OCD)|
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|Figure 4: Age-related changes of the sagittal diameter of the lesser pelvis (DCD)|
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|Figure 5: Age-related changes of the sagittal diameter of the lesser pelvis (Pelvic cavity)|
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|Figure 6: Age-related changes of the sagittal diameter of the lesser pelvis (Outlet 1)|
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|Figure 7: Age-related changes of the sagittal diameter of the lesser pelvis (Outlet 2)|
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Each parameter for both the age groups was evaluated for statistically significant difference and is presented in [Table 3]. Except for the pelvic cavity and pelvic outlet 2, all other diameters show significant change with regard to age.
|Table 3: Statistical significant difference in the comparison of each diameter between the two age groups|
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| Discussion|| |
Various studies in the past have been carried out to analyze different pelvic diameters in females using CT or MRI images (Daghighi et al., 2013; Harper et al., 2012; Korhonen et al., 2010; and Huerta-Enochian et al., 2006). However, there are only few studies done to determine normal pelvic diameters in the general population with relation to age (Oksana, 2014; Vazquez-Barragan et al., 2016; and Lenhard et al., 2009). The present study was carried out to assess the sagittal diameters at six levels of female lesser pelvis and to analyze age-related changes in these diameters in Gujarati Indian female population.
The mean anatomical conjugate in our study is nearer with that obtained by Vázquez-Barragán et al. in Mexican population (11.65 ± 0.99) but differs much with studies done by Mostafa et al. (11.90 ± 0.29) in Egyptian population, Decker et al. (12.68 ± 0.87) in American population, and Kolesova (13.50 ± 0.85) in Latvian population. The same was found in the case of diagonal conjugate where the mean value of the present study coincides with the results obtained in Mexican population (Vázquez-Barragán et al., 2016) but differs much from Latvian population (Oksana, 2014). In the present study, OCD varies from 9.06 to 14.68, whereas the same in other reported studies varies from 9.6 to 14.4 (Daghighi et al.) and 10.3–14.5 (Huerta-Enochian et al.) The mean of OCD in our study is lower than the studies done by Salk et al. (11.28 ± 0.84), Vázquez Barragán et al. (11.73 ± 0.98), Lenhard et al. (11.8 ± 0.2 and 12 ± 0.9), and Daghighi et al. (12.55 ± 0.84). This may be due to variance in physical constitutions of different races and suggests that populations and values determined in one population cannot be applied to the other.
Sagittal diameter at the level of pelvic cavity increases with age [Figure 5], but changes in diameter are not statistically significant (P = 0.6038) which is in conformity with the study done by Oksana (2014). The mean pelvic outlet 2 diameter in the present study is 8.97 ± 0.99 which is much lower than 10.80 ± 1.13 in American population (Decker et al., 2011), 9.99 ± 0.98 in Latvian population (Oksana, 2014), and 10.65 ± 0.54 in Egyptian population (Mostafa et al., 2016). In the same manner, mean pelvic outlet 1 diameter of the present study also differs from the values found in Turkish population (Salk et al., 2016).
Sacral anatomical orientation angle is age dependent as inclination of sacrum becomes more horizontal with increasing age, which can be attributed to vertical posture causing changes in sacroiliac joints along with reduction of their mobility (Peleg et al., 2007). This results in reduction in anteroposterior diameters of the inlet of pelvis associated with the increase in corresponding diameters of outlet (Weisl, 1955). The present study shows that anatomical, obstetric, and diagonal conjugates decrease with increasing age [Figure 2], [Figure 3], [Figure 4]. Females more than 40 years of age presented significantly smaller diameters than those between 20 and 40 years of age. This finding is in confirmation with that of Vázquez-Barragán et al. in Mexican population. The sagittal diameters of pelvic outlet 1 and pelvic outlet 2 increase with increasing age [Figure 6] and [Figure 7], and the change in pelvic outlet 1 is significant but that in pelvic outlet 2 is not significant which may be attributed to the mobility of the coccyx. Our findings are in accordance with previous studies that pelvic inlet diameters are significantly affected with increasing age.
It is also observed that age-related changes including horizontalization of pelvic bone system can contribute to the development of pelvic floor dysfunction as well as pelvic organ prolapse. This is more common in females with shorter sagittal diameter of pelvic inlet and longer sagittal diameter of pelvic outlet (Lazarevski, 2004).
| Conclusions|| |
In the present study, normal values of ACD, OCD, DCD, and sagittal diameters of pelvic cavity and outlets are derived. It is found that the sagittal diameters of inlet decrease with age and the changes are statistically significant. Among the other diameters, age-related changes in outlet 1 are statistically significant. This suggests that age-related changes of the lesser pelvis are more marked at the levels of the inlet and the outlet and less in the area of the cavity and coccyx. It is very important to determine the morphometric parameters of the pelvis in our population as these can help in diagnosing cephalopelvic disproportion as well as pelvic dysfunction and pelvic organ prolapse.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]
[Table 1], [Table 2], [Table 3]