The document summarizes key anatomical structures of the knee, lower leg, and ankle. It describes the tibia, fibula, patella, knee joint, tibiofibular joints, ligaments, muscles, and bony landmarks. The knee joint is a complex joint formed by the femur, tibia, and patella. It contains cruciate and collateral ligaments that stabilize the joint. Muscles of the leg are divided into anterior, posterior, and lateral compartments that plantarflex, dorsiflex, invert and evert the foot. The tibia and fibula articulate proximally and distally to form the tibiofibular joints.

1. Lecture 3 : Tibia, Fibula, Knee, Tibiofibular and
Patellofemoral Joint
By
Hermizan Halihanafiah

2. Kneecap
Small, triangular
bone located anterior
to the knee joint
Superior end is the
base
Inferior end apex

3. Posterior surface contains 2 articular facets
Patellar ligament attaches the patella to the tibial
tuberosity
Patellofemoral joint – between the posterior surface
of the patella and the patellar surface of femur
Tibiofemoral (knee joint) – intermediate component
of the posterior surface of the patella.

4. Patella increases the leverage of tendon of the
quadriceps femoris muscle.
Also maintain the position of the tendon when the
knee is bent (flexed), and protects the knee joint.

5. Known as shin bone
The larger, medial, weight-bearing bone of the leg.
Articulates at its:
proximal end with the femur and fibula
distal end with the fibula and the talus
bone of the ankle.
Tibia and fibula like the radius and ulna are
connected by interosseous membrane

7. Proximal end of tibia
Is expanded into a lateral and a medial condyle
These condyles articulate with the condyles of the
femur to form the lateral and medial tibiofemoral
joints (knee joint).
The concave condyles are separated by an upward
projection called the intercondylar eminence.
Inferior surface of the lateral condyle articulates
with the head of fibula to form proximal
tibiofibular joints.

8. Tibial tuberosity on the anterior surface is a point of
attachment for the patellar ligament.
Inferior to and continuous with the tibial tuberosity
is a sharp ridge that can be felt below the skin –
anterior border (crest) or shin

9. Distal end of tibia
Medial surface of the distal end of the tibia forms the
medial malleolus
Medial malleolus articulates with the talus of the
ankle and form the prominence on the medial
surface.
The fibular notch articulates with the distal end of
the fibula to form the distal tibiofibular joint.
Most common long bone to be fractured and with an
open or compound fracture.

13. Is parallel and lateral to the tibia and it is
considerably smaller than tibia
Proximal end of fibula
Head of fibula which is proximal end articulates
with the inferior surface of the lateral condyle of the
tibia below the level of the knee joint to form the
proximal tibiofibular joint.

14. Distal end of fibula
Distal end is more arrowhead-shaped and has a
projection called the lateral malleolus that
articulates with the talus of the ankle.
This forms the prominence on the lateral surface of
the ankle.

20. KNEE JOINT
Tibiofemoral joint
The largest & most complex joint of the body
It is a modified hinge joint that consists of three
joints within a single synovial cavity.
The knee joint joins the thigh with the leg and
consists of two articulations: one between the
femur and tibia, and one between the femur and
patella.

21. Consist of the 3 joints :
1. Laterally is a tibiofemoral joint : between
the lateral condyle of the femur, lateral
meniscus & lateral condyle of the tibia.
2. Medially is a second tibiofemoral joint :
between the medial condyle of the femur,
medial meniscus & medial condyle of the
tibia.
3. Intermediate patellofemoral joint :
between the patella & the patellar surface
of the femur.

22. Articular capsule
The articular capsule has a synovial and a fibrous
membrane separated by fatty deposits.
No complete, independent capsule unites the bones
of the knee joint.
The ligamentous sheath surrounding the joint
consists mostly of muscle tendons or their
expansions.
Some capsular fibers connecting the articulating
bones.

23. Medial & lateral patellar
retinacula
Fused tendons of insertion of the quadriceps femoris
muscle & the fascia lata that strengthen the anterior
surface of the joint.

24. Patellar ligament
Continuation of the common tendon of insertion of
quadriceps femoris muscle that extends from the
patella to the tibial tuberosity.
Strengthens the anterior surface of the joint.
The posterior surface of the ligament is separated
from the synovial membrane of the joint by an
infrapatellar fat pad.

25. Oblique popliteal
ligament
Broad, flat ligament that extends from
intercondylar fossa of the femur to the head of the
tibia & lateral condyle of the femur to the medial
condyle of the tibia.
The ligament & tendon strengthen the posterior
surface of the joint.

26. Arcuate popliteal
ligament
Extends from the lateral condyle of th femur to the
styloid process of the head of the fibula.
It strengthens the lower lateral part of the posterior
surface of the joint.

27. Tibial collateral ligament
Broad, flat ligament on the medial surface of the
joint that extends from medial condyle of the femur
to the medial condyle of the tibia.
Tendons of sartorius, gracilis & semitendinosus
muscles, all of which strengthen the medial aspect
of the joint, cross the ligament.

28. Fibular collateral
ligamentStrong, rounded ligament on the lateral surface of
the joint that extends from the lateral condyle of the
femur to the lateral side of the head of the fibula.
It strengthens the lateral aspect of the joint.
The ligament is covered by the tendon of the boceps
femoris muscle.
The tendon of the popliteal muscle is deep to the
ligament.

29. lateral restraints

30. Figure 9.28a

31. Figure 9.28b

32. Intracapsular ligament
1. Anterior cruciate ligament (ACL)
2. Posterior cruciate ligament (PCL)
 Anterior and posterior cruciate ligaments limit
anterior and posterior sliding movements.
 Medial and lateral collateral ligaments prevent
rotation of extended knee

33. Anterior cruciate ligament (ACL)
Extend posteriorly & laterally from a point anterior
to the intercondylar area of the tibia to the posterior
part of the medial surface of the lateral condyle of
the femur.
Limits hyperextension of the knee & prevent the
anterior sliding of the tibia on the femur.
Stretched or torn in about 70% of all serious knee
injuries.

34. Posterior cruciate ligament (PCL)
Extends anteriorly & medially from a depression on
the posterior intercondylar area of tibia and lateral
meniscus to the anterior part of the lateral surface of
the medial condyle of the femur.
Prevents the posterior sliding of the tibia when the
knee is flexed.
This is very important when walking down stairs or
steep incline.

36. ligaments: anterior

37. ligaments: posterior

38. Articular disc (menisci)
1. Medial meniscus
2. Lateral meniscus
 The menisci are discs of fibrocartilage attached to
tibial plateaus. They are thicker along the periphery.
 Medial and lateral meniscus absorb shock and
shape joint

39. Figure 9.28d

40. menisci

43. Bursae
 fluid sacs filled with synovial fluid that surround the
joint cavity.
 3 type:
1. Prepatellar bursa: between patella and skin
2. Infrapatellar bursa: between the upper part of the
tibia and the patellar ligament
3. Suprapatellar bursa: between the anterior surface of
the lower part of the femur and the deep surface of
the quadriceps femoris

45. Tibiofibular Joint
Situated between tibia
and fibula
Divide into:
Proximal and distal
tibiofibular joint.

46. Proximal Tibiofibular Joint
Articulation surface:
between head of fibula and
inferior surface lateral
condyle of tibia
Type: planar joint
Slightly movement
Anterior and posterior
ligaments of head of fibula.

47. Distal tibiofibular Joint
Articulation surface: The fibular notch
articulates with the distal end of the fibula to form
the distal tibiofibular joint.
Syndesmosis – connecting materials is a
interosseous membrane.

48. Figure 9.29

49. MOVEMENT KNEE JOINT
Flexion
Extension

50. MUSCLES OF THE LEG
Muscles that move the foot and toes are located in
the leg.
Muscles in the leg divided by the deep fascia into 3
compartment :
a) Anterior compartment
b) Posterior compartment
c) Lateral compartment

51. ANTERIOR
COMPARTMENT
Consists of muscles the dorsiflexors of the foot.
 Tibialis anterior
 Extensor hallucis longus
 Extensor digitorum longus
 Fubularis (peroneus) tertius

52. Tibialis anterior
Long, thick muscle againts the
lateral surface of the tibia
Origin : lateral condyle & body of
tibia and interosseous membrane.
Insertion : 1st
metatarsal and 1st
cuneiform
Action : dorsiflexes foot at ankle
joint and inverts foot at intertarsal
joint.
Innervation : deep fibular
(peroneal) nerve.

53. Extensor hallucis longus
Is a thin muscle between & partly
deep to the tibialis anterior
Origin : anterior surface of fibula
and interosseous membrane.
Insertion : distal phalanx of great
toe.
Action : dorsiflexes foot at ankle
joint and extends proximal phalanx
of great toe at metatarsophalangeal
joint.
Innervation : deep fibular
(peroneal) nerve.

54. Extensor digitorum longus
Origin : lateral condyle of tibia,
anterior surface of fibula and
interosseous membrane.
Insertion : middle & distal phalanges
of toes 2 – 5
Action : dorsiflexes foot at ankle joint
and extends distal and middle
phalanges of each toe at
interphalangeal joints and proximal
phalanx of each toe at
metatarsophalangeal joint.
Innervation : deep fibular (peroneal)
nerve.

55. Fibularis (peroneus) tertius
Origin : distal 3rd
of fibula
and interosseous membrane
Insertion : base of fifth
metatarsal.
Action : dorsiflexes foot at
ankle joint and everts foot at
intertarsal joints.
Innervation : deep fibular
(peroneal) nerve.

57. LATERAL COMPARTMENT (FIBULAR)
Contains two muscles that plantar flex and evert the
foot :
a) fibularis (peroneus) longus
b) fibularis (peroneus) brevis
Both plantar flex and evert the foot.
Provides lift and forward thrust.

58. Fibularis (peroneus) longus
Origin : head and body of
fibula and lateral condyle of
tibia.
Insertion : 1st
metatarsal and 1st
cuneiform
Action : plantar flexes foot at
the ankle joint and everts foot
at intertarsal joints.
Innervation : superficial
fibular (peroneal) nerve.

59. Fibularis (peroneus) brevis
Origin : body of fibula
Insertion : base of fifth
metatarsal
Action : plantar flexes foot at the
ankle joint and everts foot at
intertarsal joints.
Innervation : superficial fibular
(peroneal) nerve.

61. POSTERIOR
COMPARTMENT
Consists of muscles in superficial and deep groups :
Superficial group of plantar flexors :
1. Gastrocnemius
2. Soleus
3. Plantaris
Deep group of plantar flexors :
1. tibialis posterior
2. flexor digitorum longus
3. flexor hallucis longus
4. popliteus (unlocks the knee joint for knee flexion)

62. Superficial group of plantar flexors :
1. Gastrocnemius
2. Soleus
3. Plantaris

63. Gastrocnemius- Origin : lateral & medial
condyles of femur and capsule of
knee
- Insertion : calcaneus by way of
calcaneal (Archilles) tendon
- Action : Plantar flexes foot at
ankle joint & flexes leg at knee
joint
- Innervation : tibial nerve

64. Soleus
- Origin : head of fibula &
medial border of tibia
- Insertion : calcaneus by way
of calcaneal (Archilles) tendon
- Action : Plantar flexes foot at
ankle joint
- Innervation : tibial nerve

65. Plantaris- Origin : femur superior to lateral
condyle.
- Insertion : calcaneus by way of
calcaneal (Archilles) tendon
- Action : Plantar flexes foot at
ankle joint & flexes leg at knee
joint
- Innervation : tibial nerve

68. Deep group of plantar flexors :
1. tibialis posterior
2. flexor digitorum longus
3. flexor hallucis longus
4. popliteus

69. Popliteus- Origin : lateral condyle of
femur
- Insertion : proximal tibia
- Action : flexes leg at knee
joint & medially rotates
tibia to unlock the
extended knee.
- Innervation : tibial nerve

70. Tibialis posterior
- Origin : tibia, fibula &
interosseous membrane.
- Insertion : second, third &
fourth metatarsals,
navicular, all three
cuneiforms and cuboid.
- Action : plantar flexes foot
at ankle joint & inverts foot
at intertarsal joints.
- Innervation : tibial nerve

71. Flexor digitorum longus
- Origin : posterior surface of tibia
- Insertion : distal phalanges of toes 2
- 5
- Action : plantar flexes foot at ankle
joint, flexes distal & middle phalanges
of each toe at interphalangeal joint &
proximal phalanx of each toe at
metatarsophalangeal joint.
- Innervation : tibial nerve

72. Flexor hallucis longus
- Origin : inferior two-thirds of
fibula
- Insertion : distal phalanx of great
toe
- Action : plantar flexes foot at
ankle joint, flexes distal phalanx of
great toe at interphalangeal joint &
proximal phalanx of each toe
metatarsophalangeal joint.
- Innervation : tibial nerve

78. Diamond shaped space on the posterior aspect of the
knee
The popliteal fossa is a space or shallow depression
located at the back of the knee-joint
The bones of the popliteal fossa are the femur and
the tibia.
It is referred to as a "knee pit."

79. The boundaries of the fossa are :
superior and medial:
the semitendinosus muscle (semimembranosus is
medial to the semitendinosus.)
superior and lateral:
the biceps femoris muscle
inferior and medial:
the medial head of the gastrocnemius muscle
inferior and lateral:
the lateral head of the gastrocnemius muscle

80. The roof is formed by (from superficial to deep) :
1. Skin.
2. Superficial fascia which contains short
saphenous
vein, three cutaneous nerves i.e, terminal branch of
posterior cutaneous nerve of thigh, posterior
division of medial cutaneous nerve,
and peroneal or sural communicating
nerve.
3. Deep fascia or popliteal fascia.

81. The floor is formed by :
1. The popliteal surface of femur
2. Capsule of knee joint and the oblique
Popliteal ligament
3. Strong fascia covering the Popliteal
muscle

82. Contents of popliteal fossa :
popliteal artery, which is a continuation of the
femoral artery
popliteal vein
tibial nerve
common peroneal nerve
Six or seven popliteal lymph nodes are
embedded in the fat
The roof contains a portion of the small
saphenous vein and posterior cutaneous nerve of
the thigh.

85. Popliteal fossa
Tendon of
semimembranosus
muscle
Tendon of
biceps femoris
muscle

86. Clinical significance
Injuries to the popliteal fossa are relatively
uncommon. The surrounding muscles can
sometimes experience small tears which cause
pain and inflammation in the joint. The
development of inflammation /cyst in the
popliteal fossa can put pressure on the nerves and
blood supply, causing problems in the lower leg.