Sexual Variations in the Pelvis

Caldwell, William E.; Moloy, Howard C.

doi:10.1126/science.76.1958.37

Cited by 20 publications

(8 citation statements)

References 3 publications

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“…Third, we chose pelvic width as an anatomical factor instead of pelvic type. We found in a review of the literature that there was no evidence supporting the relationship between nerve position and pelvic type [ 49 ]. Fourth, instead of measuring distances on 2D MRI scans, it would be more reliable to make 3D reconstructions in software Mimics® (Materialise, Leuven, Belgium) of the soft tissue of interest, i.e., the three nerves, and to relate this course/distance to the 3D bony landmarks with the use of an X, Y, Z axis system.…”

Section: Discussionmentioning

confidence: 99%

Distances between bony landmarks and adjacent nerves: anatomical factors that may influence retractor placement in total hip replacement surgery

et al. 2016

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BackgroundRetractor placement is a leading cause of intraoperative nerve injury during total hip replacement (THR) surgery. The sciatic nerve, femoral nerve, and superior gluteal nerve are most commonly affected. This study aimed to identify the distances from bony landmarks in the hip to the adjacent nerves on magnetic resonance imaging (MRI) and the associations between anatomical factors and these distances that would guide the placement of retractors during THR surgery, in order to minimize the risk of nerve injury.MethodsWe reviewed hip MRIs of 263 adults and recorded the distances from (1) the anterior acetabular rim to the femoral nerve; (2) the superior acetabular rim to the superior gluteal nerve; (3) the posterior acetabular rim to the sciatic nerve; and (4) the greater trochanter to the sciatic nerve. The effects of anatomical factors (i.e., gender, age, body height, body mass index (BMI), pelvic width, and acetabular version and morphology) on these distances were analyzed.ResultsDistances from bony landmarks to adjacent nerves (in cm) were 2.06 ± 0.44, 2.23 ± 0.28, 1.94 ± 0.81, and 4.83 ± 0.26 for the anterior acetabular rim, superior acetabular rim, posterior acetabular rim, and greater trochanter, respectively, and were shorter in women than in men (P < 0.001). Multivariate analysis identified body height as the most influential factor (P < 0.001). Linear regression demonstrated a strong positive linear correlation between body height and these distances (Pearson’s r = 0.808, 0.823, 0.818, and 0.792, respectively (P < 0.001)).ConclusionsThe distances from bony landmarks to adjacent nerves provide useful information for placing retractors without causing nerve injury during THR surgery. Shorter patients will have shorter distances from bony landmarks to adjacent nerves, prompting more careful placement of retractors.

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Section: Discussionmentioning

confidence: 99%

Distances between bony landmarks and adjacent nerves: anatomical factors that may influence retractor placement in total hip replacement surgery

et al. 2016

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“…However, if the subpubic arch is narrow, the fetus is forced posteriorly until there is sufficient space for delivery. The obstetrical disadvantage of a narrow subpubic arch can be offset by a compensatory increase in the posterior compartment of the outlet, that is, in the posterior sagittal diameter (Williams, 1909, 1911; Thoms, 1915; Acosta‐Sison and Calderon, 1919; Caldwell and Moloy, 1932). Cunningham et al (2001: 56) stated that, “In obstructed labors caused by a narrowing of the midpelvis or pelvic outlet, the prognosis for vaginal delivery often depends on the length of the posterior sagittal diameter of the pelvic outlet.” However, conjoint contraction of the subpubic arch and posterior sagittal diameter (e.g., latter due to sacral–coccygeal fusion) may result in an obstetrically inadequate outlet—“If the narrow [subpubic] arch is also associated with a forward projecting sacral tip or fused coccyx (causing a shortening of the lower antero‐posterior, and posterior sagittal outlet diameters) delivery may be arrested by an outlet obstruction” (Moir, 1947: 23).…”

Section: Discussionmentioning

confidence: 99%

“…The explanation is that the posterior sagittal diameter of the outlet and subpubic arch are part of different anatomical complexes. The posterior sagittal diameter is determined, in part, by displacement of the lower part of the sacrum and coccyx from the ischia by sacral angulation, and the subpubic arch are determined by lateral flare of the ischia and ischiopubic rami (Caldwell and Moloy, 1932; Caldwell et al, 1934; Thoms et al, 1939; Tague, 1992, 2000). This anatomical independence between the posterior sagittal diameter and subpubic arch lowers the probability of their conjoint contraction 3…”

Section: Discussionmentioning

confidence: 99%

Fusion of coccyx to sacrum in humans: Prevalence, correlates, and effect on pelvic size, with obstetrical and evolutionary implications

Tague

2011

American J Phys Anthropol

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Humans do not have a tail, but we have four rudimentary coccygeal vertebrae. This study considers several issues pertaining to fusion of the coccyx to the sacrum, including prevalence, sexual differences, effect on pelvic size, and obstetrical and evolutionary implications. Previous research on sacral-coccygeal fusion has reported: (1) lower prevalence in females than males, (2) prevalence increases with age, (3) range in prevalence among 13 samples from 0 to 72%, and (4) obstetrical complications. This study uses a sample of 2,354 American skeletons of known sex, age 20 years and older to ascertain prevalence of sacral-coccygeal fusion and to evaluate some of its correlates. Results show that the sexes do not differ in prevalence of sacral-coccygeal fusion for five of seven decades of life, but that prevalence does increase with advancing age-from 24 to 47% from the third to eighth decades of life in females. Pelvimetric analysis of 132 females shows that those with sacral-coccygeal fusion have a shorter posterior sagittal diameter of the outlet compared to those without fusion; more than half of those with sacral-coccygeal fusion have an obstetrically contracted posterior sagittal diameter. Shortening of the posterior sagittal diameter is important, because its conjoint occurrence with a narrow subpubic arch may result in an obstetrically inadequate outlet. This study concludes that sacral-coccygeal fusion is a principal contributor to the evolution of sexual dimorphism in sacral angulation, which is a determinant of the length of the posterior sagittal diameter of the outlet.

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“…Consequently, they have been considered to be reliable sex discriminators (Caldwell and Moloy, 1932;Lazorthes and Lhez, 1939;Letterman, 1941;Genovés, 1959;Jovanovic and Zivanovic, 1965;Jovanovic et al, 1968;Singh and Potturi, 1978;Taylor and DiBennardo, 1984;Novotný, 1986;Patriquin et al, 2005), although they are not the best. The most efficient morphological discriminators of sex relate to the pubic bone (MacLaughlin and Bruce, 1986;Walker, 2005).…”

Section: Introductionmentioning

confidence: 99%

Curvature of the greater sciatic notch in sexing the human pelvis

Takahashi

2006

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The maximum curvature of the greater sciatic notch and two standardized indices were calculated for use in the sexing of human hip bones. This was done by means of quadratic regression of the contour points of the greater sciatic notch. The new variables are not directly affected by the osteometric landmarks (e.g. ischial spine, tubercle of the piriformis, and posterior inferior iliac spine) which determine the greatest width of the notch. These landmarks are, however, known to be ill-defined on occasion, but nevertheless have been used to derive the conventional depth-to-width index and angles of the sciatic notch. The curvature parameter and its new indices were applied to the sciatic notch of 164 Japanese hip bones of known sex (104 males and 61 females). The accuracy of the new variables in the determination of sex was assessed and compared with that of the conventional indices and angles of the sciatic notch. The best discriminating variable was found to be the posterior angle with an accuracy of 91%. The new parameters of the present study that represent localized shape of the sharply curved edge of the notch diagnosed sex with an accuracy of 88%. In paleoanthropological or forensic cases, using the maximum curvature of the sciatic notch and its indices may be applicable to sexing the hip bones of specimens with postmortem damage.

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Sexual Variations in the Pelvis

Cited by 20 publications

References 3 publications

Distances between bony landmarks and adjacent nerves: anatomical factors that may influence retractor placement in total hip replacement surgery

Distances between bony landmarks and adjacent nerves: anatomical factors that may influence retractor placement in total hip replacement surgery

Fusion of coccyx to sacrum in humans: Prevalence, correlates, and effect on pelvic size, with obstetrical and evolutionary implications

Curvature of the greater sciatic notch in sexing the human pelvis

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