2. The Tibia
• The tibia is the main bone of the leg, forming
what is more commonly known as the shin.
• It is the second largest bone within the body
situated on the medial side in the leg.
• The tibia is the pre-axial bone and
homologous with the lateral bone of the
forearm, the radius.
• It carries weight of the body from femur to
the foot.
3.
4. PARTS
• The tibia is a long bone and is composed of 3 parts:
– Upper end, lower end, and shaft.
• The upper end is enlarged and bears notable medial
and lateral condyles and tibial tuberosity.
– The medial condyle is bigger in relation to the lateral
condyle.
• The shaft has:
– 3 borders:Anterior , medial, and lateral;
– 3 surfaces- Medial, lateral, and posterior.
• The lower end is small and projects medially and
inferiorly as medial malleolus.
5.
6.
7.
8. ANATOMICAL POSITION AND SIDE DECISION
• The side of tibia is determined by holding the
bone vertically in this type of manner that:
–Its expanded end with condyles faces upward.
–Its tibial tuberosity and sharp sinuous anterior
border of the shaft faces anteriorly.
–Medial malleolus is on the medial side.
–Superior surface of the upper end (tibial
plateau) is located in a horizontal plane.
10. UPPER END
• The upper end of the tibia is markedly
expanded from side to side, to form two large
condyles which overhang the posterior
surface of the shaft.
• The upper end includes:
–(a) A medial condyle,
–(b) A lateral condyle,
–(c) An intercondylar area,
–(d) A tuberosity.
14. Tibial plateau
•The condyles form a flat surface,
known as the tibial plateau.
•This structure articulates with the
femoral condyles to form the
major articulation of the knee
joint.
15. The tibial condyles
• Medial condyle(two main feature):
– Surface on the medial condyle is oval (long axis
anteroposterior) in conformity with the medial femoral
condyle and meniscus.
– It has a transverse groove on posterior aspect for the
insertion of semimembransus muscle.
– The peripheral flattened part is covered by the fibrocartilaginous plate,
the medial meniscus.
• Lateral condyle(two main feature):
– The lateral surface is a little smaller and more nearly
circular, in conformity with the lateral femoral condyle
and meniscus.
– It has a smaller facet for the head of fibula.
– It is separated from the femur by the lateral meniscus.
17. Attachments on the Medial Condyle
(a) The semimembranosus is inserted into the
groove on the posterior surface.
(b) The capsular ligament of the knee joint is
attached to the upper border, which also
gives attachment to the deeper fibres of the
tibial collateral ligament.
(c) The medial patellar retinaculum is attached to
the anterior surface.
18.
19. Gerdy's tubercle
• Gerdy's tubercle or tuberculum gerdy is a smooth
triangular shaped facet present in the proximal end
of the tibia.
• It is located on the anterolateral surface of the
lateral condyle, below the joint line (between femur
and tibia), lateral to the tibial tuberosity.
• Here the iliotibial tract inserts.
20.
21. Medial Condyle
• Superior Surface
• The peripheral flattened part is covered by the
fibrocartilaginous plate, the medial meniscus.
• Posterior Surface
• It presents a deep transverse groove for the
insertion of tendon of semimembranosus.
• Anterior and Medial Surfaces
• The anterior and medial surfaces are marked by
the vascular foramina and adjoining margin gives
connection to the medial patellar retinaculum
22. Lateral Condyle
• Superior Surface:
• The flattened peripheral part is covered by a plate of
fibrocartilage- the lateral meniscus.
• Posterior Surface:
• Inferolaterally this surface presents a circular smooth
articular facet for the head of fibula.
• Between the articular facet for the fibula and the margin of
superior surface there’s a shallow groove for the tendon
of popliteus.
• Anterior and Lateral Surfaces:
• The anterior surface has a flat triangular facet for the
connection of the iliotibial tract “Gerdy's tubercle ”
• Anterior and lateral surfaces supply connection to the
lateral patellar retinaculum.
23. Intercondylar Area
• 1. It’s the rough area on the superior surface of the
upper end of tibia between the articular surfaces of 2
condyles.
• 2. The middle of intercondylar area is narrow and
marked by an elevation referred to as intercondylar
eminence.
– This consists of two tubercles and a roughened area.
– This area is the main site of attachment for the ligaments and
the menisci of the knee joint.
– The tibial intercondylar tubercles fit into the intercondylar
fossa of the femur.
• 3. From before backwards, the intercondylar area gives
attachments to 6 structures.
24. The intercondylar area gives
attachments to 6 structures.
From before backwards
1. Anterior horn of Medial meniscus.
2. Anterior Cruciate ligament.
3. Anterior horn of Lateral meniscus.
4. Posterior horn of Lateral meniscus.
5. Posterior horn of Medial meniscus.
6. Posterior Cruciate ligament.
– Mnemonic: Medical College London, London Medical
College.
25. The condyles form a flat surface,
known as the tibial plateau.
This structure articulates with the femoral condyles
26. Tibial Tuberosity
• It is a large bony projection in the apex of rough
triangular area situated on the anterior aspect of
upper end of the tibia.
• It’s split into an upper smooth and a lower rough
part.
– Upper smooth part gives connection to the ligamentum
patellae.
– Lower rough part is linked to the subcutaneous
infrapatellar bursa which divides it from the skin.
• Rough triangular area above the tuberosity is linked
to the deep infrapatellar bursa.
27. SHAFT
• The shaft of the tibia is 3 sided prism in shape.
• It has:
– Three borders: anterior, medial and interosseous;
– Three surfaces: lateral, medial and posterior.
28. Shaft(borders)
• Anterior Border (Shin of the Tibia)
• It is the sharpest, subcutaneous, and
sinuous in course.
• It is subcutaneous and forms the shin.
• It is distinct in upper 2/3rd only.
• It extends from the tibial tuberosity
above to the anterior border of the
medial malleolus below.
29. Shaft
• Medial Border
• It extends from the medial condyle to the
posterior border of medial malleolus.
• The medial border is rounded,is distinct in
middle 1/3rd.
• The soleal line joins the medial border in the
junction of its upper one-third with the lower
two-third.
30. Shaft(surfaces)
• Lateral (Interosseous) Border
• It is sharp and goes from the lateral condyle below
the facet for the head of fibula to the anterior
border of fibular notch.
• The interosseous or lateral border is distinct in
middle 1/3rd only.
• It gives connection to the interosseous membrane
which connects the tibia and fibula.
• Its distal part breaks up to enclose a triangular
notch for the connection of interosseous inferior
tibiofibular ligament.
31. Shaft
• Medial Surface:
• It faces anteromedially and is located between the
anterior and medial borders.
• It’s just about solely subcutaneous.
• Its upper part near the medial border gets
insertions of 3 muscles.
– From before backwards, these are: sartorius, gracilis,
and semitendinosus.
• Mnemonic: Girl between 2 surgeons ‘SGS’.
32. Shaft
• Lateral Surface:
• It’s directed anterolaterally and is located between
anterior and interosseous edges.
• Its upper two-third gives origin to the tibialis anterior.
• Its lower one-third is crossed by these structures from
medial to lateral sides while going from the leg to the
foot:
(a) Tibialis anterior.
(b) Extensor hallucis longus.
(c) Anterior tibial artery.
(d) Deep peroneal nerve/anterior tibial nerve.
(e) Extensor digitorum longus.
(f) Peroneus tertius.
Mnemonic: The Himalayas Are Not Dry Dry Plateaus
33. Shaft
• Posterior surface:
• It is located between the medial and lateral
borders.
• It has two line.
–The soleal line
–A vertical line
• A rough bony ridge goes from the fibular facet
to the junction of upper and middle thirds of
the medial border named soleal line.
• Cont.
34. The soleal line
–This line gives attachments to
these structures from above
downward:
–Fascia covering popliteus.
–Fascia covering soleus.
–Soleus (origin).
–Deep transverse fascia.
35. A vertical line
• A large area below the soleal line is split into a
medial and a lateral part by a vertical ridge.
– The nutritional foramen of the tibia is situated at
the upper end of the vertical ridge.
• The flexor digitorum longus originates from the
medial area below the soleal line.
• The tibialis posterior originates from the lateral area
below the soleal line.
36. Shaft
• The lower quarter of the posterior surface
underneath the flexor retinaculum is
associated with these structures from
medial to lateral:
–Tibialis posterior.
–Flexor digitorum longus.
–Posterior tibial artery.
–Tibial nerve.
–Flexor hallucis longus.
• Mnemonic: The Doctors Are Not Hunters.
38. LOWER END
• The lower end of the tibia is slightly expanded.
• It widens to help with weight bearing.
• It has five surfaces.
• Medially, it is prolonged downwards as the medial
malleolus.
• On the posterior surface of the tibia, there is
a groove where the tendon of the tibialis posterior
muscle passes through.
• Laterally, on the distal end, there is a notch, where
the fibula is bound to the tibia. It is known as
the fibular notch.
39.
40. Anterior relations
of the lower end of the tibia
• 1. The anterior aspect of the lower end of the tibia
(which is continuous with the lateral surface of the
shaft) is crossed by the tendons of the following
muscles
(from medial to lateral side)
– (a) Tibialis anterior
– (b) Extensor hallucis longus
– (c) Extensor digitorum longus.
– (d) Peroneus tertius.
• 2. The anterior tibial vessels and the deep peroneal
nerve cross the anterior aspect of the lower end of the
bone lying between the tendons of the extensor
hallucis longus and the extensor digitorum longus.
41.
42. Posterior relations
of the lower end of the tibia
• The posterior aspect of the lower end of the tibia is
crossed by tendons of the following muscles
(from medial to lateral side).
– (a) Tibialis posterior
– (b) Flexor digitorum longus
– (c) Flexor hallucis longus
• The tendon of the flexor digitorum longus crosses that
of the tibialis posterior near the lower end of the bone.
• The posterior tibial vessels and nerve cross the
posterior aspect of the lower end of the bone lying
between the tendons of the flexor digitorum longus
and the flexor hallucis longus.
43. Surfaces of the Lower End of Tibia
1. Anterior surface has no special features.
2. Posterior surface in its medial part presents a
groove for the tendon of tibialis posterior.
3. Medial surface is subcutaneous and is
constant with the medial surface of the
medial malleolus.
4. Lateral surface presents a fibular notch.
5. Inferior surface is smooth and articulates
with the body of the talus in the ankle joint.
44. Medial Malleolus
• Its tip is located at a higher level than that of the
lateral malleolus and gives connection to
the deltoid ligament.
• Its lateral surfaces present a comma-shaped
articular facet for articulation together with the
quite similar facet on the medial outermost layer of
the body of the talus.
• Its posterior surface presents a vertical groove for
the tendon of tibialis posterior.
• Medial margin of the groove is notable and gives
connection to the flexor retinaculum.
45. CAPSULAR ATTACHMENTS AT THE UPPER
AND LOWER ENDS OF TIBIA
• At the upper end, the capsule is connected to the
margins of tibial condyles medially, laterally, and
posteriorly. Anteriorly it is connected to the sides of
triangular area on the anterior aspect of condyles
combining with all the medial and lateral patellar
retinacula and to the tibial tuberosity where it
combines with the ligamentum patellae.
• Behind the lateral condyle, the capsule is deficient for
the passage of tendon of popliteus.
• At the lower end, the capsule is connected to the
margins of articular surfaces where it goes on to the
lower end of fibula.
46. OSSIFICATION
• The tibia ossifies from 3 centers- 1 primary and 2 secondary.
• 1. Primary center appears in the middle of shaft in the age of
seventh week of intrauterine life.
• 2. Secondary centers.
• (a) For the upper end:
– At birth or soon after beginning.
– Fusion with all the shaft: 20 years.
• (b) For the lower end:
– 2 years.
– Fusion with all the shaft 18 years.
• The upper epiphysis goes anteriorly as a tongue like process
to create the upper part of tibial tuberosity.
47. CLINICAL SIGNIFICANCE
• OSTEOMYELITIS OF THE UPPER END OF
TIBIA
• The upper end of tibia is the commonest
site of acute osteomyelitis, but knee
joint stay unaffected since the capsule
of knee joint is connected near to the
margins of articular surfaces proximal to
the epiphyseal line.
48. Clinical Relevance: Fractures of the Tibia
• Fractures of the tibia are relatively common, and
occur most frequently in the middle aged and
elderly. If the fibula is not fractured, it supports the
tibia, and displacement of the fragments is minimal.
• The proximal end of the tibia is the site that is most
vulnerable to damage, resulting usually from some
traumatic accident e.g vehicular.
• At the ankle, the medial malleolus can be fractured.
This is caused by the ankle being twisted inwards
(over-inversion) – the talus of the foot is forced
against the medial malleolus, causing a spiral fracture.
52. FRACTURE OF TIBIA
• The tibia is normally fractured in the junction of
upper 2/3rd and lower 1/3rd of its shaft. (The tibial
shaft is narrowest at the junction of upper two-third
and lower two-third, therefore the commonest site
of fracture.).
• The lower two-third of the tibial shaft is empty area
(thus devoid of any muscular connection) and have
low blood supply; for this motive, the fractures in
the lower 1/3rd of the shaft of tibia show delayed
union or non union.
