close

Вход

Забыли?

вход по аккаунту

?

Anatomical and developmental bases for the ventral arc of the human pubis.

код для вставкиСкачать
AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 82:73-79 (1990)
Anatomical and Developmental Bases for the Ventral Arc of the
Human Pubis
LINDA C BUDINOFF AND ROBERT G TAGUE
Department of Anthropology, Kent State Uniuerszty, Kent, Ohio 44242
(L C B I , Department of Geography and Anthropology, Louisiana State
University, Baton Rouge, LouLsiana 70803 ( R G T )
Pelvic anatomy, Pubic length, Sex determination,
KEY WORDS
Ventral rampart of pubis
ABSTRACT
The ventral arc of the pubis is frequently used for sexing adult
human hip bones. This study addresses the issues of the anatomical and
developmental bases for the ventral arc. Dissection of seven adult pelves (four
females and three males) demonstrates that the sexes are identical in the
muscular and ligamentous attachments to this ridge of bone. The tendons of
gracilis and adductor brevis, which are fused for a variable extent, arise from
the ridge of bone, and the fibers of the ventral pubic ligament attach to its
medial border. Lateral placement of the ventral arc is defined in terms of the
minimum distance between the ridge of bone and the inferior border of the
symphyseal face of the pubis. The hypothesis that lateral placement of the
ventral arc is positively correlated with pubic length was tested using two
random samples of adult female hip bones (N = 50 for both whites and blacks)
from the Hamann-Todd collection. The correlation between these variables is
significant. The results support the argument that lateral placement of the
ventral arc is related to the amount of postadolescent growth occurring at the
symphyseal border of the pubis. Therefore, the ventral arc should not be
considered as an independent criterion from pubic length in sexing adult hip
bones.
In humans, the hip bone is diagnostic for
determining sex from skeletal remains.
There have been numerous studies on the
anatomical and developmental bases for sexual dimorphism in pubic length, pelvic
breadth, shapes of the greater sciatic notch
and subpubic arch, and bone resorption adjacent to the pelvic joints; the ventral arc,
however, has received little attention. The
ventral arc is one of three traits (the other
two being the subpubic arch and medial
aspect of the ischiopubic ramus) that make
up Phenice’s (1969) technique for sexing
the adult hip bone. Of the three traits, Phenice (1969:300) regarded the ventral arc as
being the “least likely to be ambi OUS” in
sex determination (but see Love 1, 1989).
Sutherland and Suchey (1987)also found the
ventral arc to be reliable in distinguishing
between the sexes.
Phenice (1969:298) described the ventral
arc as “a slightly elevated ridge of bone that
extends from the pubic crest and arcs inferiorly across the ventral surface to the lateral
Y
0 1990 WILEY-IASS, INC
most extension of the subpubic concavity . . .
where it blends with the medial border of the
ischio-pubicramus.” Sutherland and Suche
(1987)agreed with this description and mo ified it only minimally b stating that the
definitive arc must be pa pable. Both Phenice (1969)and Sutherland and Suchey (1987)
concluded that the corresponding ridge of
bone in males generally follows a different
course on the ventral aspect of the pubic
cor us.
Zommentaries on the anatomy of the ventral arc have been few. Todd (1920:311)
stated that “the linear prominence appearing on the ventral aspect [of the pubis is] . . .
the line of attachment of the acilis muscle.”
Cleland (1889, cited in E d d , 1920:292)
wrote that “the line in question will always
be seen marked by a distinct ridge, with a
flattened surface extending inwards from it,
covered . . . by the superficial ligament of the
B
P
Received June 10, 1988; accepted June 9, 1989.
74
L.C. BUDINOFF AND R.G. TAGUE
symphysis.” More recently, Buikstra and
Mielke (1985:374)stated that the structures
associated with Phenice’s method are “anatomically related to the attachment of the
crus penis and crus clitoris.” Bass (1987:201)
discussed Phenice’s method under the heading “Attachment of the Arcuate Ligament.”
Remarkably, texts on human gross anatomy
(for example, Hollinshead, 1974; Moore,
1980; Williams and Warwick, 1980; Woodburne, 1983) fail to mention the sexual dimorphism in the ventral arc and, correspondingly, the tissues that attach to this
ridge of bone. However, these anatomical
texts are uniform in describing the crura as
attaching to the ischiopubic ramus and the
arcuate ligament as arching across the inferior aspect of the symphysis pubic to attach
to the inferior pubis ramus. Therefore, Buikstra and Mielke’s (1985) and Bass’ (1987)
statements on anatomy pertain to the
breadth of the ischiopubic ramus and subpubic arch, but not to the ventral arc.
Only Todd (1920,1921a)andKerley(1977)
have discussed the developmental basis of
the arc. Todd (1921a:38) suggested that “the
ridge is not marked until after the ventral
rampart has been formed.. . [and] the
marking out of the line in question is causally related to the growth of bone tissue as a
rampart upon the ventral bevelled symphysial area.” Kerley (1977) suggested that sexual dimorphism of the ventral arc results
from differential growth at the symphyseal
border of the pubis.
This study addresses two issues pertaining to the ventral arc. First, the discussion
presented above demonstrates that the anatomical relationships of the ventral arc remain unresolved. Moreover, are sexual differences in this ridge of bone accompanied by
soft tissue differences? Second, is lateral
placement of the ventral arc (symphysis-arc
length) positively correlated with pubic
length (see Fig. l)?The latter tests the hypothesis that lateral placement of the ventral arc is directly related to pubic growth.
MATERIALS AND METHODS
Seven cadavers were available to evaluate
the anatomy of the ventral arc. All seven
specimens (four females and three males)
were white and were from individuals older
than 50 years of age.
To examine the relationship between lateral placement of the ventral arc and pubic
length, two random samples of adult female
hiD bones (50 whites and 50 blacks) were
Fig. 1. Pubic length (A-B): middle of acetabulum to
inferior border of symphyseal face of pubis. Symphysisarc length (B-C): minimum distance from inferior border
of syrnphyseal face of pubis to ventral arc. Ischial length
(A-D): maximum distance from middle of acetabulum to
ischial tuberosity. Acetabulum-arc length: pubic length
minus symphysis-arc length. Femoral length: maximum
length. Ischio-pubic index: pubic length x 100/ischial
length.
selected from the Hamann-Todd skeletal collection. Only specimens with a complete or
virtually complete ventral rampart of the
pubis were sampled (see Discussion for significance of the ventral rampart to formation
of the ventral arc). The variables analyzed in
this study are illustrated and defined in
Figure 1. Measurements were taken on the
left hip bone and femur whenever possible.
This part of the study was restricted to one
sex because both variables of interest (symphysis-arc length and pubic length) are sexually dimorphic. A correlational analysis using a mixed-sex sample would obscure the
relationship between these variables.
RESULTS
The dissections show that the sexes are
identical in the muscular and ligamentous
attachments pertaining to the ventral arc.
Both the gracilis and adductor brevis muscles arise from this ridge of bone, adductor
brevis from the superior border and gracilis
from the inferior border. The inferior portion
of the adductor brevis tendon and the superior portion of the gracilis tendon fuse (although the extent of this fusion varies among
individuals). and this combined tendon
arises from the intermediate section of the
ridge (Fig. 2a-c).
75
VENTRAL ARC OF THE HUMAN PUBIS
a
C
b
d
Fig. 2. Ventral pubis dissection. a: Muscles and superficial ventral pubic ligament. Abbreviations: AB, adductor brevis; AL, adductor longus; AM, adductor magnus; GR, gracilis; IL, inguinal ligament; OE, obturator
externus; PE, pectineus; PY pyramidalis; RA, rectus
abdominis; VPL, ventral pubic ligament. b: Fusion of
gracilis and adductor brevis muscles. c: Origin of muscles. d: Ventral pubic ligament: deep layer (top) and
deepest layer (bottom).
Attached to the medial aspect of the ridge
of bone are fibers of the ventral pubic ligament. There are several layers of these ligamentous fibers. The superficial fibers run
obliquely and attach to dense connective tissue directly overlying the ridge of bone (Fig.
2a). The deeper fibers run transversely and
attach to the medial border of this ridge (Fig.
2d). These transverse fibers cover the interpubic disk, thicken inferiorly, and blend into
the arcuate ligament.
Phenice (1969) described the ventral arc
76
L.C. BUDINOFF AND R.G. TAGUE
as extending from the pubic crest to the
ischiopubicramus. As observed in this study,
the ridge reached as far as the pubic crest in
none of the dissected specimens and in only
25% of those from the Hamann-Todd sample.
We surmise that adductor longus has a partial attachment to the ridge in those specimens where the arc does reach the pubic
crest (Fig. 2c).
The second part of this study tested the
hypothesis that lateral placement of the ventral arc (symphysis-arc length) is positively
correlated with pubic length. Table 1 presents the summary statistics for the variables. White females have a significantly
longer pubis than black females. However, of
the two components of pubic length (symphysis-arc length and acetabulum-arc
length), whites are significantly different
from blacks only in acetabulum-arc length.
Also, note that the coefficient of variation is
higher for symphysis-arc length than for all
other variables.
The results of the correlational analysis
are presented in Table 2. The correlations
between pubic length and symphysis-arc
length are significant in whites (r = 0.461,
blacks (r = 0.291, and the combined sample
(r = 0.39). Symphysis-arc length is significantly correlated with the ischiopubic index
in whites (r = 0.44) and the combined sample (r = 0.351, but the correlation is nonsignificant in blacks (r = 0.20). Not surprisingly, acetabulum-arc length (the principal
component of pubic length) is positively correlated with pubic length and the ischiopubic index in whites, blacks, and the combined sample. Interestingly, the correlation
between symphysis-arc length and acetabulum-arc length is low and nonsignificant in
whites (r = 0.091, blacks (r = -0.20), and
the combined sample (r = -0.03). Finally,
the measures of body size used in this study
(femoral length and ischial length) are significantly correlated with pubic length and
acetabulum-arc length in whites, blacks, and
the combined sample. In contrast, the correlations between symphysis-arc length and
measures of body size are low and nonsignificant in whites and blacks; the results for the
combined sample are equivocal.
DISCUSSION
Although males and females generally differ in the course taken by the ridge of bone on
the ventral aspect of the pubic corpus, the
sexes are identical in the muscular and ligamentous attachments to that ridge. The anatomical observations presented in this
study principally are in agreement with
those ofTodd (1920)and Cleland (1889, cited
in Todd, 1920). Todd (1920) described gracilis as attaching to the ridge of bone, and
Cleland (1889, cited in Todd, 1920:292)
stated that this ridge was the “inner limit of
attachment of the femoral muscles” and that
the ridge’s medial surface was “covered. . .
by the superficial ligament of the symphysis.” However, the specimens in this study
uniformly show that both gracilis and adductor brevis attach to the ridge.
The observations in this study differ somewhat from the anatomical descriptions of
Hollinshead (19741, Moore (19801, Williams
and Warwick (19801,and Woodburne (1983).
These anatomists describe adductor brevis
as arising from the pubis between gracilis
and obturator externus. The specimens in
this study show that gracilis and adductor
brevis share a common tendinous origin for a
variable extent along this ridge of bone.
Phenice (1969:300)cautioned that the results of his study were based on observations
of adult specimens and that the technique he
proposed may not be reliable for subadults in
that “there are indications that the ventral
TABLE 1. Summary statistics for white and black females, a n d results of Student$ t-tests comparing the
means between these groups of females’,2
Pubic length
Symphysis-arc length
Acetabulum-arc length
Ischial length
Femoral length
Ischiopubic index
Whites (N = 50)
X
SD
CV3
X
84.2
10.8
73.4
76.2
413
110.4
5.6
2.1
5.0
3.8
25
5.3
6.68
19.54
6.85
5.01
6.08
4.82
81.5
10.3
71.2
75.3
435
108.3
-.-
Variables
‘All measurements are reported in millimeters.
‘A two-tail test of significance was used.
1 he Coefficient of variation (CV) is corrected for bias, where CV = (11
*Prob. < 0.05.
+‘Prt,b. < 0.001.
3,.
Blacks (N = 50)
SD
cv3
4.6
2.3
4.5
3.9
21
3.4
5.67
22.44
6.35
5.21
4.85
3.16
+ 1/4N1 X CVk) X 100 (see Sokal and Rohlf, 1981:S9)
t Test
*
ns
*
ns
**
*
77
VENTRAL. ARC OF THE HUMAN PUBIS
TABLE 2. Prodoct-moment correlaiion coefficients for white a n d black females and for the combined samrtle’
Whites (N = 50)
Symphysis-arc length
Pubic length
Symphysis-arc length
Acetabulum-arc length
0.46
-
-
(***)
Acetabulum-arc length
Ischial length
0.93’
0.09
(***I
(4
0.68
(***)
Femoral length
0.38
(**)
Ischiopubic index
Blacks (N = 50)
Syrnphysis-arc length
Acetabulum-arc length
0.65
Combined sample (N = 100)
Symphysis-arc length
0.29
-
-
(*I
(***)
(***)
-0.20
(ns)
0.20
(ns)
0.20
( 4
0.20
(ns)
0.39
-
-
0.88
0.83
0.50
0.43
(***)
Acetabulum-arc length
(**)
0.54
(***)
(***)
Ischiopubic index
0.34
(***)
(***)
Femoral length
0.69
(***)
(***)
(***)
Ischial length
0.17
(ns)
0.21
(ns)
0.44
0.9i
0.75
0.41
(**)
0.34
(**)
-
(***)
Ischial length
Femoral length
Ischiopubic index
0.75
0.72
(***)
(***)
0.27
0.23
(**)
(9
0.59
0.49
I***)
(***I
‘A one-tail test of significance was used.
*Prob. < 0.09.
**Pmb. < 0.01.
***Prob. < 0,001.
arc and the subpubic concavity are not well pubis precedes that of the ventral margin,
developed until the female has reached creating the ventral bevel. Following formaabout 20 ears of age.” This caveat was tion of the ventral bevel, there is a build-up of
confirmed y Sutherland and Suchey (19871, bone along the ventral margin of the pubis.
who observed that the majority of adolescent The bone added along the ventral margin is
females do not show an arc. Sutherland and the ventral rampart. Rampart formation
Suchey’s results show that a precursor of an may commence in the early part of the third
arc (that is, a nonpalpable line) is the modal decade of life, and it is typically completed in
morphology among females by age 20, and a the fourth decade (Todd, 1920, 1921a;
definite ventral arc (that is, a palpable ridge) Meindl et al., 1985;Brooks and Suchey, n.d.1.
Todd (1921~)
and Meindl et al. (1985)have
is the modal morphology by age 23.
We agree with Todd (1920, 1921a) and argued that the ventral rampart is essenKerley (1977)that the ventral arc is related tially a delayed epiphysis. Todd (1921b)
t o growth of the pubis at the symphyseal observed that in other mammals the symborder, but, as pubic growth at the symphy- physeal epiphysis of the pubis is a true episis occurs throughout childhood and adoles- physis; it develops as a separate bony elecence, why is the development of the ventral ment that later fuses with its pubic corpus.
regarded
arc typically delayed until early in the third In humans, however, Todd (1921~)
decade of life? Beginning late in the second the epiphysis as “retrogressive”because it is
decade of life, there develops an asynchrony not developmentally independent from the
in bone growth at the symphyseal border of pubic corpus. Rather, the ventral margin of
the pubis. Growth of the dorsal margin of the the symphyseal border of the human pubis
t
78
L.C. BUDINOFF AND R.G. TAGUE
develops either by the fusion of a series of
ossific nodules or by the simple accretion of
bone.
Evidently, the ventral arc is “displaced”
laterally from the symphyseal border of the
pubis as a result of late epiphyseal (ventral
rampart) formation. “It is the formation of
the ventral rampart that causes the muscular attachment to recede from the edge of the
pubis”(Todd,1920:325),but why is this ridge
of bone not “displaced” until early adulthood? We contend that during early pubic
growth the muscles of the ventral pubis have
a periosteal attachment, which causes them
to retain their same position with respect to
the symphyseal border (cf. Grant, 1978;
Grant et al., 1981). However, an osseous
attachment for these muscles replaces the
periosteal attachment either immediately
before or during the period of asynchrony in
pubic growth. Further migration of the muscles with continued bone growth is precluded. The subsequent development of the
ventral rampart then “displaces”the attachment site for gracilis and adductor brevis
from the symph seal border of the pubis.
Sutherland and uchey’s (1987) precursor of
a ventral arc may be a visualization of the
relationship between the attachment site for
gracilis and adductor brevis and the developing ventral bevel, and the palpable ventral
arc may be a consequence of the osseous
attachment of these muscles.
The results of this study showing a positive correlation between symphysis-arc
length and pubic length support the interpretation that lateral placement of the ventral arc (symphysis-arc length) is a consequence of pubic growth. Although the
analysis in this study was restricted to females, we regard the interpretation as applicable to both sexes; there are few differences
between the sexes in the sequence in metamorphosis of the symphyseal face of the pubis (Todd, 1920, 1921a; Meindl et al., 1985;
Brooks and Suchey, n.d.1. The reason the
ridge of bone “sweeps more widely” from the
symphyseal border of the pubis in females
than males is a sexual difference in the
amount of postadolescent growth of the pubis. After age 18 years, significant growth of
the pubis continues in females but not in
males ( T a p e , 1986). Todd (1920) had also
suggested that pubic growth in males ends at
approximately age 18 and that “the prominence of the ventral rampart in the female
suggests more vigorous growth or a longer
$7
period of growth at the symphysis” (Todd,
1921a:38). Finally, results from Coleman’s
(1969) study explain why this ridge of bone
takes an arc-like path near the inferior border of the pubis. Coleman (1969:141) noted
that “at the inferior border of the pubic symphysis . . . there is a larger amount of total
growth than . . . [at] the superior border.”
As argued, symphysis-arc length (lateral
placement of the ventral arc) is derived from
ventral rampart formation, The results of
this study suggest five implications. First,
pubic growth due to ventral rampart formation is markedly variable, as evidenced by
the high coefficient of variation for symphysis-arc length (Table 1).Second, the ventral
rampart’s contribution to pubic length is not
significantly related to measures of body
size, such as the lengths of the femur and
ischium. In contrast, pubic length and acetabulum-arc length are significantly correlated with these measures of body size (Table
2). Similarly, Moerman (1981) has shown
that pubic length is directly related to stature. Third, symphysis-arc length and acetabulum-arc length are independent in their
contributions to pubic length, as evidenced
by the low and nonsignificant correlations
between the two components of pubic length
(Table 2). Fourth, white and black females do
not differ significantly in symphysis-arc
length. Therefore, the difference between
the groups in pubic length is due principally
to growth unassociated with the ventral
rampart (Table 1). Fifth, symphysis-arc
length is directly associated with pubic
length (Table 2). This result implies that
lateral placement of the ventral arc cannot
be considered as an independent trait from
pubic length in sexing the adult hip bone.
Rather, pubic length and the ventral arc
provide overlapping information for sex determination. Sutherland and Suchey (1987)
observed that 4% of the males in their sample show a morphology that might be interpreted as a ventral arc. We speculate that
these males have long pubes.
CONCLUSIONS
Osteologists regard the ventral arc as diagnostic in sexing adult human hip bones.
Although the sexes differ in the course taken
by this ridge of bone on the pubic corpus,
males and females are identical in the muscular and ligamentous attachments to this
ridge. The tendons of gracilis and adductor
brevis, which are fused for a variable extent,
VENTRAL ARC OF THE HUMAN PUBIS
79
arise from the ridge of bone, and the fibers of Grant PG, Buschang PH, Drolet DW, and Pickerel1 C
(1981) The effect of changes in muscle function and
the ventral pubic ligament attach to its mebone growth on muscle migration. Am. J. Phys. Andial border.
thropol. 54547-553.
Lateral placement of the ventral arc (sym- Hollinshead WH (1974) Textbook of Anatomy. Hagersphysis-arc length) is directly related to pubic
town, MD: Harper and Row.
length. This association results from epiphy- Kerley ER (1977) Forensic anthropology. In CG Tedeschi, WG Eckert, and LG Tedeschi (eds.): Forensic
seal (ventral rampart) formation at the symMedicine: A Study in Trauma and Environmental
physeal border of the pubis. Therefore, the
Hazards: Vol. 11. Physical Trauma. Philadelphia: W.B.
ventral arc and pubic length cannot be conSaunders Co., pp. 1101-1115.
sidered as independent traits for purposes of Love11 NC (1989) Test of Phenice’s technique for determining sex from the 0s pubis. Am J Phys Anthropol
sexing adult hip bones.
ACKNOWLEDGMENTS
We thank Bruce Latimer and the Cleveland Museum of Natural History for allowing us to study skeletal material in their
care. Discussions with Douglas Bailey,
Bruce Latimer, Owen Lovejoy, Richard
Meindl, Judy Suchey, and Steven Ward were
helpful in the preparation of this manuscript. Portions of this paper were presented
at the 57th Annual Meeting of the American
Association of Physical Anthropologists
(1988).
LITERATURE CITED
Bass WM (1987) Human Osteology: A Laboratory and
Field Manual, 3rd ed. Columbia, MO: Missouri Archaeological Society (Special Publication No. 2).
Brooks S, and Suchey JM (n.d.1Skeletal age determination based on the 0s pubis: A comparison of the AcsadiNemeskeri and Suchey-Brooks methods. Manuscript
in possession of authors.
Buikstra J E , and Mielke J H (1985) Demography, diet,
and health. In RI Gilbert Jr, and H J Mielke (eds.):The
Analysis of Prehistoric Diets. New York: Academic
Press, pp. 359-422.
Cleland J (1889)On certain distinctions of form hitherto
unnoticed in the human pelvis, characteristic of sex,
age and race. Memoirs Memoranda Anat. 1:95-103.
Coleman WH (1969) Sex differences in the growth of the
human bony pelvis. Am. J . Phys. Anthropol. 31:125-152.
Grant PG (1978)The effect of position on the migration of
muscle. J. Anat. 127t157-162.
79:117-120.
Meindl RS, Lovejo CO, Mensforth RP, and Walker RA
(1985) A revisedrmethod of age determination using
the 0s pubis, with a review and tests of accuracy of
other current methods of pubic symphyseal aging. Am.
J . Phys. Anthropol. 68:29-45.
Moerman ML (1981)A Longitudinal Study of Growth in
Relation to Body Size and Sexual Dimorphism in the
Human Pelvis. Ph.D. dissertation, Ann Arbor, University of Michigan.
Moore KL. (1980) Clinically Oriented Anatomy. Baltimore: Williams and Wilkins Co.
Phenice TW (1969) A newly developed visual method of
sexing the 0s pubis. Am. J. Phys. Anthropol. 30:297302.
Sokal RR, and Rohlf FJ (1981)Biometry. San Francisco:
W.H. Freeman and Co.
Sutherland LD, and Suchey J M (1987)Use of the ventral
arc in sex determination of the 0s pubis. Poster presentation, 39th Annual Meeting of the American Academy
of Forensic Sciences, Physical Anthropology Section,
San Diego, CA.
Tague RG (1986) Obstetric Adaptations of the Human
Bony Pelvis. Ph.D. dissertation, Kent, Ohio, Kent
State University.
Todd TW (1920) Age changes in the ubic bone I The
male White pubis. Am. J . Phys. Antlropol. 3:2851334.
Todd TW (1921a)Age changes in the pubic bone: 11. The
pubis ofthe male Negro-White hybrid; 111: The pubis of
the White female. IV.The pubis of the female NegroWhite hybrid. Am. J. Phys. Anthropol. 4:l-70.
Todd TW (1921b) Age changes in the pubic bone: V.
Mammalian pubic metamorphosis. Am. J. Phys. Anthropol. 4:333406.
Todd TW (1921c)Age changes in the pubic bone: VI. The
interpretation of variations in the symphysial area.
Am. J . Phys. Anthropol. 4:407-424.
Williams PL, and Warwick R (1980) Gray’s Anatomy,
British Edition. Philadelphia: W.B. Saunders Co.
Woodburne RT (1983) Essentials of Human Anatomy.
New York: Oxford University Press.
Документ
Категория
Без категории
Просмотров
0
Размер файла
586 Кб
Теги
development, base, ventral, arc, anatomical, human, pubic
1/--страниц
Пожаловаться на содержимое документа