Morphology of long bones, their formation and Identification

1. JHARKHANDRAKSHASHAKTIUNIVERSITY
(Established byStateGovernment and recognised byUGC )
MEURS’Road , Near SKIPA ,Ranchi-834008
By
Mr. Ayush Kumar
Department of Forensic Science
Morphology of Long bones

2. BONE
• Bone isacalcified,living,connectivetissue that
formsthemajorityof skeletalsystem.
It’s a Intercellular
calcifiedmatrixwhich consistof collagenfibre.
• It’s Functions isto:-
–Providesupportivestructureto the body.
– It actsasaprotectorof internal organslike Brain,
Lungs ,Heartetc.
–Actsasareservoirin the body.
–Actsasalever mechanisminmovement.
–Actsasacontainerin the body.

3. Type of Bone
• COMPACT BONE:-
– Compactboneis a densebonetissue composedof
osteons, which canresist pressureandshocksand
this ishow it protects the spongytissue.
–Compactboneforms especiallythe diaphysis of the
Longbones.
•SPONGY BONE:-
–Spongybonesaretissuemadeof bonycompartments
separated by cavities filled with bonemarrow, blood
vesselsandnerves.
–Thisgivesbonestheir lightness.

4. Classification o f bone according t o
their shape :-
–Longbone
–Short bone
–Flat bone
–Irregularbone
–Sesamoidbone

5. Characteristics o f Long Bone :-
•Longbonesarelongerthan they arewide.
•Theyreflects the elongated shaperather than the
overall size.
•Theyconsistof a shaft plus two endsandare
constructed primarily ofcompact bone.
• Theymay contain substantial amounts of spongy
bone.
• All bonesof the limbs arelong bonesexceptthe
patella, wristand ankle bones.
• Exampleof longbonesare:- Humerus, Radius,Ulna
,Tibia, Fibula ,Femur .

6. Parts o f long bone
Structure o f Long Bone

7. EPIPHYSIS:-
– Areexpandedarticular ends,separated from the shaft by the epiphyseal plate
,during bonegrowth ,composedof a spongybonesurroundedby a thinlayer of
compact bone.
ProximalEpiphysis
- Enlarged terminal part of the bonewhich arenearestto the centre of the body.
Distal Epiphysis
- Enlarged terminal part of the bonewhich are farthest from the centre of the body.
METAPHYSIS:-
– Part of the bone between the epiphysis and thediathesis which contains the
connecting cartilage enabling the bone to grow which disappears at
adulthood.
DIAPHYSIS:-
– Elongated hollow central portion of the bone located between the
metaphysics made of compact tissue encloses the modularly cavity.

8. OSTEON:-
– It’s the elementary cylindrical structure of the compact bone that runs parallel to
the longest axis of bonewhich surroundsand opensinto Haversian canal.
HAVERSIAN CANAL:-
–It’s the lengthwise central canal of the osteonwhich comprise of encloseblood
vesselsandnerves.
VOLKMANN’S CANALS:-
– Perforating canal which is also transverse canals of the compact bone enclosing
blood vessels and nerves connecting the Haversian canals with the medullary
cavity and theperiosteum.
MEDULLARYCAVITY:-
– Cylindricalcentral cavity of the bonecontaining the bonemarrow alsoencloses
lipid-rich yellow bonemarrow.

9. PERIOSTEUM:-
– Periosteumis the fibrous membrane rich in blood vesselsthat envelopes the bone
which contributes especially to the bone’s growth inthickness which’s anchored to
the boneitself bybits of collagen calledSharpey’s perforating fibres.
CONCENTRIC LAMELLAE:-
–Thebonylayersof osteon made of collagen fibres which are arranged concentrically
around the Haversian canal and form asthe bonesgrow.
ARTICULAR CARTILAGE:-
– It’s the smooth resistant elastic tissue coveringthe terminal part of the bonewhich
facilitates movement and absorbsshocks.
BLOOD VESSEL:-
–Thechannel in the bonethrough which the blood circulates, carrying the nutrients and
mineral salts thebone requires.
BONE MARROW:-
–It’s the soft substance contained in bonecavities,producing blood cellswhich’s red in
children, yellow in the long bonesof adults.

10. HUMERUSBONE
HumerusBone
Bony landmarksof the distalhumerus
The proximal aspect of the humerus

11. PROXIMAL LANDMARKS
 Theproximalhumerus ismarked bya head,anatomical neck,surgical neck,greater
and lesser tubercles and intertubercularsulcus.
 Theupper endof the humerus consists of the head.Thisfaces medially,upwards and
backwards and is separated from the greater and lessertubercles by the anatomical
neck.
 Thesurgical neckruns from just distal to the tuberclesto the shaft of the humerus.
 Theaxillary nerve andcircumflex humeral vesselslie against the bonehere.
 Theshaftof the humerus isthe site of attachment for various muscles.Crosssection
views reveal it to becircular proximally and flattened distally.
 Onthe lateral sideof the humeral shaft isa roughened surfacewhere the deltoid
muscle attaches.Thisisknown isasthe deltoidtuberosity.

12.  The radial(orspiral)groove isashallow depression that runs diagonally down the
posterior surface of the humerus, parallel to thedeltoid tuberosity.
 Theradialnerveandprofunda brachiiarterylieinthis groove.
 The following muscles attach to the humerus along its shaft:
Anteriorly – coracobrachialis, deltoid, brachialis,brachioradialis.
Posteriorly – medialand lateralheads ofthe triceps (the spiralgroove demarcates
their respective origins).
 Thelateraland medialborders of the distal humerus form medialand
lateral supraepicondylar ridges.

Also located on the distal portion of the humerus are three depressions, known as
the coronoid, radial and olecranon fossae. They accommodate the forearm bones
during flexion orextension at theelbow.

13. TIBIA (SHINBONE)

15. UPPER END
 It hastwo endie. upperandlower endandinterveningshaft.
 It hastwo condylesie.Medialandlateral condyle .Themedialcondyleisoval
in shapeand lateral condyle is circular and smaller in shapein between
thesetwo there isa intercondylarareawhich isalsoknown astibialspine.
 In the centrethere is a shallowdepressedareaandthe peripheralareais
flattenedwhich isrelatedto lateral Meniscus.
 Theanteriorandlateral surfaceof lateral condyleshowsmultiple vascular
foramina.
 The lateral surfacehasflat circular articular facet for the headof fibula and
togetherthesetwo forms superiortibiofibularjoint.

16. SHAFT
 It hasthree bordersandthree surface.
 Anterior border which is most prominent of the three extending from
tibialtuberosityto the anteriormarginof medial malleolus.Itissinuousand
prominentin upper2/3but smooth andround below.
 Medial border extendsfrom medial condyle to the posteriorborder of medial
malleolus. It’s smooth and round aboveand below but more prominent in
center.
 Lateral /interosseous borderis thin and prominent, specially its centre part
which extends from Articular facet and below it splits to form a rough fibular
notch.

17. LOWER END
 It ismuch smaller than upper endhaving five surfaces ie. anterior, lateral, posterior,
medial andinferior
Medial surface isprolonged downward asa strong processknown asmedialmalleolus
which issubcutaneous and it’s continuation of the medial surface of the shaft.
Anteriorsurface isthe continuation of the lateral surface of theShaft.
Lateral surface hasa fibular notch.
Posterior surfaceisthe continuation of posterior surface of theShaft and medially it
shows agroove.
Interior surface isarticular and comesin contact with the articular systemof the body
of talus it’s quadrilateral and smooth.

18. FEMUR BONE

19. FEMUR isfound in the thigh which isthe largest bonein the bodyand isthe
only bonein the upper legwith spongy bonesat both endsand a cavity filled with
bonemarrow in theshaft.
 Below the head of the femur is the neckand the greater trochanter which attaches
to tendons that connect to the gluteus minimus andthe gluteus medius muscle.This
isknown asan extension of the legor the hip.
Head :articulates with the acetabulum of the pelvis to form the hip joint having a
smooth surface coveredwith articularcartilage.
Neck :Connectsthe headof the femur with the shaft which isa cylindrical, projecting in a
superior and medial direction. It is set at an angle of approx. 135degree to the
shaft.
Greatertrochanter:the most lateral palpable projection of bonethat originate from the
anterior aspectsjust lateral to the neck.

20. Lesser trochanter:It’s smaller than the greater trochanter and projects from the
posteromedial sideof the femur just inferior to the neckshaft junction.
Medial and lateral condyles: It’s round areasat the end of the femur. Theposterior
and inferior surface articulates with the tibia and menisci of the knee, while the
anterior surfacearticulates with the patella.
Medial and lateralepicondyles: bonyelevation on the non-articular areasof the
condyles.

21. ULNABONE

22.  ULNA isoneof two bonesthat givestructureto the forearm.Theulnais
located onthe sideof the forearmfrom the little finger.
 It joinswith the humerusonits largerendto makethe elbowjoint, andjoins
with the carpal bonesof the handat its smallerendtogetherwith the radius,
the ulnaenablesthe wrist joint to rotate.
 Theproximal endof the ulna articulates with the trochlea of the humerus. To
enable movement at the elbow joint the ulna has a specialised structure with
bony prominencesformuscleattachment.
 Important landmarksof the proximalulnaarethe olecranon,coronoid
process,trochlear notch, radial notch andthe tuberosityof ulna:-

23.  Olecranon – a large projection of bone that extends proximally, forming part of trochlear
notch. It can bepalpated asthe ‘tip’ of the elbow. Thetriceps brachii muscle attaches to its
superior surface.
 Coronoid process –this ridge of boneprojects outwards anteriorly, forming part of the
trochlear notch.
 Trochlear notch–formed by the olecranon and coronoid process.It iswrench shaped, and
articulates with the trochleaof the humerus.
 Radial notch –located on the lateral surfaceof thetrochlear notch this area articulates
with the headof the radius.
 Tuberosity of ulna – a roughening immediately distal to the coronoid process. It is where
the brachialis muscleattaches.
 Styloid process–aprojection on the lateral head of ulna.
 The distal end of the ulna is much smaller in diameter than the proximal end. It is
mostly unremarkable, terminating in a rounded head, with distal projection – the
ulnar styloidprocess.
 The head articulates with the ulnarnotch of the radius to form the distal radio-ulnar
joint.

24. RADIUS BONE

25.  RADIUS bone is one of the two large bones of the forearm, the other being
the ulna which extends from the lateral side of the elbow to the thumb side of
the wrist and runs parallel to the ulna
 The ulna is shorter and smaller than the radius and is a slightly curved
longitudinally prism-
shaped long bone.
 Head of radius is a disk shaped structure, with a concave articulating surface
and is thicker
medially, where it takes part in the proximal radioulnar joint.
 Neck is a narrow area of bone, which lies between the radial head and radial
tuberosity.
 Radial tuberosity is a bony projection, which serves as the place of
attachment of the biceps brachii muscle.
 Distal Region of the Radius is the radial shaft expands to form a rectangular
end.

26.  The lateral side projects distally as the styloid process.
 In the medial surface, there is a concavity, called the ulnar notch, which
articulates with the
head of ulna, forming the distal radioulnar joint.
 The distal surface of the radius has two facets, for articulation with
the scaphoid and lunate carpal bones. This makes up the wrist joint.

27. FIBULA BONE

28. FIBULA isthe long, thin, lateral boneof the lower leg and ishomologous to ulna of the
forearm.
In Latin, the term fibula means “pin”; therefore the lateral boneof leg is rightly
referredto asfibula becauseit’s along pin like bonewhich runs parallel to the tibia or
shin boneand plays a significant role in stabilizing the ankle and supporting the
muscles of the lowerleg.
Proximal or Upper end of the fibula includes a head and a neckthe upper endis
slightly expanded in all directions making an irregular quadrate form Its superior
surface bearsa circular articular facet directed upward, forward, and medialward, for
articulation with a corresponding surface on the lateral condyle of the tibia.
 On the lateral sideis a thick and rough prominence continued behind into a pointed
eminence, the apexor styloid process, which projects upward from the posterior part
of thehead.
 Immediately belowthe head, the fibula constricts and the part isreferredto asneck
of thefibula.

29. TheShaft of the fibula is slim and its shape is moulded by attached muscles and
therefore shows considerable variation in its form.
Ithas three borders and three surfaces:-
Anterior, Posterior, Interosseous borders & medial, lateral and posterior.
Distal orLower end of the fibula also known as the lateralmalleolus and along
with the inferiorsurface of the tibia the tip of the lateral malleolus is 0.5cm
lower than that of the medial malleolus, and its anterior surface is 1.5cm
posterior to that of themedial malleolus.
 Ithas four surfaces :-
Anterior surface is rough and round and gives connection to the anterior talofibular
ligament. A notch at its lower border gives connection to the calcaneofibular
ligament.
Posterior surfacepresents a groove, which lodges tendons of peroneus brevis and
peroneus longus, the latter being superficial to the former.
Medial surface presents a triangular articular surface in front and a depression
(malleolar fossa) below and behind it.
Lateral surface is triangular and subcutaneous.

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