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