Topic :Pelvis and Medico legal importance
Presenter : Dr. Soreingam Ragui
Moderator : Prof. H. Nabachandra
INTRODUCTION• The hip bone ossifies from 3 primary and five
sec centres.
• The primary centres appear at :
• 2nd month IUL : Ilium
• 4th month IUL : ischium
• 5th month IUL : pubis
• At birth the hip bone is ossified, except for three cartilaginous part the iliac crest,the Y –shaped cartilage and a strip along the inferior margin of the bone including the ischial tuberosity.
The pelvis is the region of the body surrounded by the pelvic bones and the inferior elements of the vertebral column.
• The bony pelvis if formed by four bone.
• right and left pelvic bones ( In front and lat)
• The sacrum and coccyx ( Behind )
• Four joints : two sacroiliac jnts, pubic symphysis ,sacrococcygeal jnt.
MEDIAL VIEW
LATERAL VIEW
• Terms
• Pelvic inlet
• pelvic inlet is an oblique plane, making an angle of 50 to 60 deg with the horizontal.
• Post : Sacral promontory.
• Ant : upper margin of pubic symphysis.
• On each side : Linea terminalis.
• Pelvic outlet
• Ant : inferior pubic ligament
• Post : coccyx
• On each side : Ischiopubic Rami
• Pelvic inlet
• Ant post diameter : upper border of symphysis to sacral promontory
• Transverse diameter : Widest part of the pelvic brim
• Oblique diameter : iliopubic imminence to opp sacrio iliac joint.
• Pelvic index ( Turner ) = a-p or conjugate diam X 100• max trans diam• Three types :• Platypellic = X to 89.9 ( trans oval ) • Mesatipellic = 90 to 94.9 ( Rounded )• Dolichopellic = 95 to X ( long oval )• Greulish and thomas :• Four types • 1) Dolichopellic = ap or conj dia more than max trans diam• 2 ) mesatipellic = max tranv dia is equal or exceeds it by no more• than 1 cm. • 3) brachypellic = trans dia exceeds conj dia by 1.1 to 2.9• 4) platypellic = trans dia exceeds conj by 3 cm
• MEDICOLEGAL IMPORTANCE OF PELVIS
• Identification
• 1) Sex determination.
• a) qualitative
• b) quantitative
• 2) Age determination.
• a) anti mortem : Study of ossification of bone.
• b) postmortem : Morphology of the symphyseal surface
SEX DETERMINATION
1) Qualitative method
By the study of morphological differences
TRAIT MALE FEMALE
PELVIS AS A WHOLE massive,marked muscle site Less massive,smooth
SYMPHYSIS higher lowerSUBPUBIC ANGLE V shaped,sharpe angle U shaped,divergent obtuse
OBTURATOR FORAMEN Large, often ovoid Small ,traingularACETABULUM Large, tends to direct laterally Small, tend to direct
anterolaterrallyGREATER SCIATIC NOTCH Small,close and deep Larger,wider and swallower
ISCHIO PUPIC RAMI Slightly everted Strongly everted
SACRIO ILIAC ARTICULATION large Small , obliquePREAURICULAR SULCUS Not frequent More frequent,better
developedILIUM High tend to be vertical Low,leterally divergentSACRUM Longer,narower,with more
evenly distributed curvature,often 5+segment
Shorted and broader,with tendency to marked curve at S1-2 and S3-4,5 seg rule
PELVIC BRIM Hearth shaped Circular,ellepticalTRUE PELVIS Relatively smaller Oblique, swallow and spacious
SEX DETERMINATION
• Quantitative method
• By measuring certain parameters
• Quantitative approach :( INDEX )
• Sciatic notch index : width of notch X 100 M=4 to 5
• Depth of notch F=5 to 6
•
• Washburn ischiopubic index :pubic lngth X100,M=73-94
• ischial length F=91-115
• Coporobasal sacral index:brth of 1st sacrl vertebraX100
• brth of base of sacrum
• M: 46.2 F:54.3
•
AGE DETERMINATION ( POST MORTEM )
• By observing the change in the symphyseal surface of the pubic symphysis.
• Age determination : the pubic symphysis is probably the best single criterion in deternmining age in third to fifth decade.
• four major contribution are available
• 1) Todd. (1923)
• 2) Brooks . (1955)
• 3) Mckern and Steward (1957)
• 4) Suchey and Brooks (1990)
phase Sym surfac Ossific nod Ventral mar Dorsal mar extrimities
I- (18 to 19 ) Rugged horz grove,fur,ridge
none none none No definition
II- (20 to 21 ) Grove filing dorsaly n behnd
May appear on symp sur
Ventral sur bevel begins
begins No definition
III- ( 22 to 24 ) Ridge n furrow progr going
Present almost const
Bevel more prononce
More difinit dorsal plateau
No definition
IV- (25 to26 ) Rapidly going present Bevel greatly increased
Complete dorsal plateau
Lower commencing
V- (27 to 30 ) Little change maybe Beginning of vent border
Completely defined
Lower cleareUpper forming
VI- (30 to 35) Granular appearnce retain
maybe Vent border complte
Defined Increse define upper ,lower
VII- (35 to 40) Texture finer,activity dim
maybe complete defined Carry on
VIII-(39 to 44) Smooth,no rim maybe No lipping No lipping Oval outline +
IX – (44 to 55) Rim present Maybe Iregular lipped
No lipping Carry
X – (50+) Erosion and erratic ossifi
BROKEN ----------------- --DOWN-------- -------
TODD METHOD:
SUCHEY/BROOKS METHOD (FEMALE):
SUCHEY/BROOKS METHOD (MALE):
Female Male
Phase mean S.D. 95% range mean S.D. 95% range
I 19.4 2.6 < 24 18.5 2.1 < 23
II 25.0 4.9 19-40 23.4 3.6 19-34
III 30.7 8.1 21-53 28.7 6.5 21-46
IV 38.2 10.9 26-70 35.2 9.4 23-57
V 48.1 14.6 25-83 45.6 10.4 27-66
VI 60.0 12.4 > 42 61.2 12.2 > 34
• Comparision:
• Todd found no race or sex differences
• Steward felt child bearing may be a factor in causing certain symphyseal change and concluded that assesement of age in female by this methods cannot be as accurate as in males .
AGE DETERMINATION (ANTE MORTEM )
• by observing the appearance and fusion of the ossification centres with the help of a plain x ray
Bone fusion Galstaun(bengalis) F M
Fleckers (Australian ) F M
Davies and parsons(Englanders)
Crest of illium 17-19 19-20 15-16 18 23
Ischium and pubis
8.5 8.5 7 9 28
Ischial tuberosity
20 20 20
• Conclusion
• Pelvic bone is the most important bone for sex determination and also age determination ( in 3rd and 4th decade).
• Therefore a meticulous study of the pelvic bone is required in cases where the identity of the person is not know or when the determination of age is required by law enforcing agencies.
• BROOKS, S. (1955). "Skeletal Age at Death: The Reliability of Cranial and Pubic Age Indicators", AJPA 13:567-597.
• BROOKS, S and J SUCHEY (1990). Skeletal age determination base on the Os Pubis: A Comparison of the Acsádi-Nemeskéri and Suchey-Brooks Methods." Human Evolution, 5:227-227-238.
• TODD, T (1920). "Age Changes in the Pubic Bones, I: The White Male Pubis", AJPA 3: 285-334.
• Reddy ,KSN .”the essentian of forensic medicine and toxicology “ 23 edt , 71
• Pillay, VV “text book of forensic medicine and toxicology “ 16 edt , 55
• Mathiharan,K and amrit k “Modi’s medical jurisprudence and toxicology “ 23 edt , 289
THE END