1. Bones Of The Leg Popliteal Fossa The Knee
Dr. Fadel Naim
Orthopedic Surgeon
IUG

2. PATELLA The largest sesamoid bone Triangular Its apex lies inferiorly
The posterior surface articulates with the condyles of the femur

3. PATELLA
Connected to the tuberosity of the tibia by the ligamentum patellae.
It is prevented from being displaced laterally during the action of the quadriceps muscle by:
The lower horizontal fibers of vastus medialis
The large size of the lateral condyle of the femur

4. Patella Supported by muscle bone and ligamentous structures
Muscle- through quad tendon
Medially- vastus medialis
Laterally- vastus lateralis
Superiorly- rectus femoris and vastus intermedius
Bone-
Trochlear groove
Ligamentous-
Patellar ligament
Patellar retinacula
Lateral
Medial

5. Function Increased efficiency of quadriceps
Changes line of pull
Protection of anterior knee joint

6. Functions of Patello-femoral Joint
with patella
without patella
(1) increases angle of pull of quads on tibia, improves the ratio of motive:resistive torque by 50%
(2) centralizes divergent tension of quads into a single line of action
(3) some protection of anterior aspect of knee

8. Patella
Exposed position in front of the knee joint and can easily be palpated through the skin.
It is separated from the skin by an important subcutaneous bursa

9. Tibia The large weight-bearing medial bone of the leg
It articulates with:
The condyles of the femur
The head of the fibula
The talus
The distal end of the fibula
It has an expanded upper end, a smaller lower end, and a shaft.

10. Tibia
At the upper end:
The lateral and medial condyles (sometimes called lateral and medial tibial plateaus),
Articulate with the lateral and medial condyles of the femur
Anterior and posterior intercondylar areas separate the upper articular surfaces of the tibial condyles
Intercondylar eminence lies between these areas

12. The lateral condyle possesses on its lateral aspect a small circular articular facet for the head of the fibula.
The medial condyle has on its posterior aspect the insertion of the semimembranosus muscle

13. Proximal Tibia Anatomy
Lateral tibial Plateau: convex, smaller than medial plateau
Lateral intercondylar eminence
Medial intercondylar eminence
Medial tibial plateau: concave, larger than lateral plateau
Tibial tubercle: insertion of patellar tendon
Tibial shaft
Fibular shaft
Fibular head: Styloid process of fibular head is the incertions of the lateral collateral ligament.
Gerdy's tubercle: insertion site of iliotibial band

14. The Shaft Of The Tibia Triangular in cross section
Three borders and three surfaces
Anterior, medial borders and the medial surface are subcutaneous.
The anterior border is prominent and forms the the shin.
At the junction of the anterior border with the upper end of the tibia is the tuberosity,
Receives attachment of the ligamentum patellae.
The anterior border becomes rounded below, where it becomes continuous with the medial malleolus

15. The Shaft Of The Tibia
The lateral or interosseous border gives attachment to the interosseous membrane
The posterior surface of the shaft shows an oblique line, the soleal line for the attachment of the soleus muscle

16. The lower end of the tibia is slightly expanded and on its inferior aspect shows a saddle-shaped articular surface for the talus.
The lower end is prolonged downward medially to form the medial malleolus.
The lateral surface of the medial malleolus articulates with the talus.
The lower end of the tibia shows a wide, rough depression on its lateral surface for articulation with the fibula.

17. FIBULA The slender lateral bone of the leg
No part in the articulation at the knee joint
Below it forms the lateral malleolus of the ankle joint.
No part in the transmission of body weight
Provides attachment for muscles.
An expanded upper end, a shaft, and a lower end.

18. The upper end, or head The shaft of the fibula A styloid process.
Articular surface for articulation with the lateral condyle of the tibia
The shaft of the fibula
Long and slender.
Four borders and four surfaces
The medial or interosseous border gives attachment to the interosseous membrane.

19. The lower end of the fibula
Forms the triangular lateral malleolus, which is subcutaneous.
On the medial surface of the lateral malleolus is a triangular articular facet for articulation with the lateral aspect of the talus.
Below and behind the articular facet is a depression called the malleolar fossa.

23. PATELLAR DISLOCATIONS
Congenital recurrent dislocations
caused by underdevelopment of the lateral femoral condyle.
Traumatic dislocation of the patella
results from direct trauma to the quadriceps attachments of the patella (especially the vastus medialis), with or without fracture of the patella.

25. PATELLAR FRACTURES A result of direct violence
Broken into several small fragments
Because the bone lies within the quadriceps femoris tendon, little separation of the fragments takes place.
The close relationship of the patella to the overlying skin may result in the fracture being open.
A result of indirect violence
Caused by the sudden contraction of the quadriceps
Snapping the patella across the front of the femoral condyles.
The knee is in the semiflexed position
The fracture line is transverse
Separation of the fragments usually occurs.

27. FRACTURES OF THE TIBIA Fractures of the tibia and fibula are common.
If only one bone is fractured, the other acts as a splint and displacement is minimal.
Fractures of the shaft of the tibia are often open because the entire length of the medial surface is covered only by skin and superficial fascia.

28. FRACTURES OF THE TIBIA
Fractures of the distal third of the shaft of the tibia are prone to delayed union or nonunion.
This can be because the nutrient artery is torn at the fracture line, with a consequent reduction in blood flow to the distal fragment;
The splint like action of the intact fibula prevents the proximal and distal fragments from coming into apposition.

29. Fractures of the proximal end of the tibia (tibial plateau)
Common in the middle aged and elderly
Usually result from direct violence to the lateral side of the knee joint
The tibial condyle may show:
A split fracture
Be broken up
The fracture line may pass between both condyles in the region of the intercondylar eminence.
As a result of forced abduction of the knee joint, the medial collateral ligament can also be torn or ruptured.

31. INTRAOSSEOUS INFUSION OF THE TIBIA IN THE INFANT
For the infusion of fluids and blood when it has been found impossible to obtain an intravenous line.
The bone marrow needle is directed at right angles through the skin, superficial fascia, deep fascia, and tibial periosteum and the cortex of the tibia.
Once the needle tip reaches the medulla and bone marrow, the operator senses a feeling of "give."
The position of the needle in the marrow can be confirmed by aspiration.
The transfusion may then commence.

32. Popliteal Fossa
a diamond-shaped intermuscular space situated at the back of the knee
most prominent when the knee joint is flexed.

33. BOUNDARIES

34. Popliteal Fossa It contains: The popliteal vessels
The small saphenous vein
The common peroneal nerve
Tibial nerve
The posterior cutaneous nerve of the thigh
The genicular branch of the obturator nerve
Connective tissue
Lymph nodes

36. Popliteus A thin, triangular muscle
Forms the inferior part of the floor of the popliteal fossa
The apex of its fleshy belly emerges from the joint capsule of the knee joint.
Origin:
posterior lateral condyle of femur
Insertion:
upper posterior medial surface of tibia
Action
flex knee, internally rotate knee

37. POPLITEAL ARTERY
deeply placed and enters the popliteal fossa through the opening in the adductor magnus
ends at the level of the lower border of the popliteus muscle by dividing into anterior and posterior tibial arteries.

38. POPLITEAL ARTERY Relations Branches Anteriorly: muscular branches
The popliteal surface of the femur
the knee joint
the popliteus muscle
Posteriorly:
The popliteal vein
the tibial nerve
Fascia
skin
Branches
muscular branches
articular branches to the knee.

41. POPLITEAL ANEURYSM
The pulsations of the wall of the femoral artery against the tendon of adductor magnus at the opening of the adductor magnus is thought to contribute to the cause of popliteal aneurysms.

42. SEMIMEMBRANOSUS BURSA SWELLING
The most common swelling found in the popliteal space.
It is made tense by extending the knee joint and becomes flaccid when the joint is flexed.
A baker's cyst
Centrally located
Arises as a pathologic (osteoarthritis) diverticulum of the synovial membrane through a hole in the back of the capsule of the knee joint.

44. POPLITEAL VEIN Popliteal fossa Semitendinosus Biceps femori
Formed by the junction of the venae comitantes of the anterior and posterior tibial arteries at the lower border of the popliteus muscle
It begins on the medial side of the popliteal artery.
As it ascends through the fossa, it crosses behind the popliteal artery so that it comes to lie on its lateral side
It passes through the opening in the adductor magnus to become the femoral vein.
Tributaries
Veins that correspond to branches given off by the popliteal artery.
Small saphenous vein, which perforates the deep fascia and passes between the two heads of the gastrocnemius muscle to end in the popliteal vein.
Popliteal fossa
Semitendinosus
Biceps femori
Semimembranosus
Sciatic nerve
Popliteal vein
Popliteal artery

46. ARTERIAL ANASTOMOSIS AROUND THE KNEE JOINT Genicular anastomosis
To compensate for the narrowing of the popliteal artery, which occurs during extreme flexion of the knee
around the knee joint is a profuse anastomosis of small branches of:
The femoral artery
Muscular and articular branches of the popliteal artery
Branches of the anterior and posterior tibial arteries .

47. TIBIAL NERVE The larger terminal branch of the sciatic nerve
The tibial nerve arises in the lower third of the thigh.
It runs downward through the popliteal fossa, lying first on the lateral side of the popliteal artery, then posterior to it, and finally medial to it
The popliteal vein lies between the nerve and the artery throughout its course.
The nerve enters the posterior compartment of the leg by passing beneath the soleus muscle.

48. COMMON PERONEAL NERVE The smaller terminal branch of the sciatic nerve
arises in the lower third of the thigh
It runs downward through the popliteal fossa closely following the medial border of the biceps muscle
It leaves the fossa by crossing superficially the lateral head of the gastrocnemius muscle.
It then passes behind the head of the fibula, winds laterally around the neck of the bone
it is subcutaneous and can easily be rolled against the bone

49. Dr. Fadel Naim Orthopedic Surgeon Faculty of medicine IUG
Knee
Dr. Fadel Naim
Orthopedic Surgeon
Faculty of medicine
IUG

50. Surface Anatomy

51. KNEE JOINT The largest and most complicated joint in the body.
Basically, it consists of (2+1):
Two condylar joints between:
The medial and lateral condyles of the femur
The corresponding condyles of the tibia
A gliding joint, between the patella and the patellar surface of the femur.
The fibula is not directly involved in the joint.

53. Articulation of Knee Joint
Above are the rounded condyles of the femur
Below are the condyles of the tibia and their cartilaginous menisci
hinge variety
some degree of rotatory movement is possible..
In front is the articulation between the lower end of the femur and the patella.
a synovial joint of the plane gliding variety
The articular surfaces are covered with hyaline cartilage.
Medial and lateral tibial plateaus:
The articular surfaces of the medial and lateral condyles of the tibia

54. Capsule Attached to the margins of the articular surfaces
Surrounds the sides and posterior aspect of the Joint
On the front of the joint, the capsule is absent
Permitting the synovial membrane to pouch upward beneath the quadriceps tendon, forming the suprapatellar bursa

55. Capsule
Behind the joint, the capsule is strengthened by the oblique popliteal ligament an expansion of the semimembranous muscle
An opening in the capsule behind the lateral tibial condyle permits the tendon of the popliteus to emerge

56. Capsule
On each side of the patella, the capsule is strengthened by expansions from the tendons of vastus lateralis and medialis

57. Ligaments Extracapsular
The ligamentum patellae
Attached above to the lower border of the patella and below to the tuberosity of the tibia
A continuation of the central portion of the common tendon of the quadriceps femoris muscle.
The oblique popliteal ligament
A tendinous expansion derived from the semimembranosus muscle.
It strengthens the posterior aspect of the capsule

58. Ligaments Extracapsular
The lateral collateral ligament
Cordlike attached above to the lateral condyle of the femur and below to the head of the fibula
The tendon of the popliteus muscle intervenes between the ligament and the lateral meniscus
The medial collateral ligament
A flat band and is attached above to the medial condyle of the femur and below to the medial surface of the shaft of the tibia
It is firmly attached to the edge of the medial meniscus

61. Intracapsular Ligaments
Green :ACL
Yellow: PCL
Red: Med men
Blue: Lat Men
Intracapsular Ligaments
The cruciate ligaments
Two strong intracapsular ligaments
Cross each other within the joint cavity
Named anterior and posterior, according to their tibial attachments
These important ligaments are the main bond between the femur and the tibia through out the joint's range of movement.

62. Anterior Cruciate Ligament
Attached to the anterior intercondylar area of the tibia
Passes upward, backward, and laterally
Attached to the posterior part of the medial surface of the lateral femoral condyle
Prevents posterior displacement of the femur on the tibia.
With the knee joint flexed
Prevents the tibia from being pulled anterioriy.

63. Posterior Cruciate Ligament
Attached to the posterior intercondylar area of the tibia
Passes upward, forward, and medially
Attached to the anterior part of the lateral surface of the medial femoral condyle
Prevents anterior displacement of the femur on the tibia.
With the knee joint flexed, prevents the tibia from being pulled posteriorly.

64. The ACL prevents the femur from sliding posteriorly on the tibia or the tibia from sliding anteriorly on the femur.
FEMUR
The PCL prevents the femur from sliding anteriorly on the tibia or the tibia from sliding posteriorly on the femur.
PATELLA
TIBIA

65. Tests for ACL
Lachman’s
Anterior Draw

67. Menisci C-shaped sheets of fibrocartilage.
The peripheral border is thick and attached to the capsule
The inner border is thin and concave and forms a free edge
The upper surfaces are in contact with the femoral condyles.
The lower surfaces are in contact with the tibial condyles.

68. Menisci
Each meniscus is attached to the upper surface of the tibia by anterior and posterior horns.
Because the medial meniscus is also attached to the medial collateral ligament, it is relatively immobile
Their function is to:
Deepen the articular surfaces of the tibial condyles to receive the convex femoral condyles
Serve as cushions between the two bones.

72. Synovial Membrane lines the capsule
attached to the margins of the articular surfaces
On the front and above the joint, it forms a pouch, which extends up beneath the quadriceps femoris muscle for three fingerbreadths above the patella, forming the suprapatellar bursa
This is held in position by the attachment of a small portion of the vastus intermedius muscle, called the articularis genus muscle

73. The synovial membrane is reflected forward from the posterior part of the capsule around the front of the cruciate ligaments
As a result, the cruciate ligaments lie behind the synovial cavity and are not bathed in synovial fluid.
In the anterior part of the joint, the synovial membrane is reflected backward from the posterior surface of the ligamentum patellae to form the infrapatellar fold
The free borders of the fold are termed the alar folds

75. Bursae Related to the Knee Joint
Numerous bursae are related to the knee joint.
They are found wherever skin, muscle, or tendon rubs against bone
Four are situated in front of the joint
Six are found behind the joint
The suprapatellar bursa and the popliteal bursa always communicate with the joint, and the semimembranosus bursa may communicate with the joint.

76. Bursae Related to the Knee Joint Anterior Bursae
The suprapatellar bursa
The prepatellar bursa
The superficial infrapatellar bursa
The deep infrapatellar bursa

77. Posterior Bursae The popliteal bursa The semimembranosus bursa
The remaining four bursae are found related to the tendon of insertion of:
The biceps femoris
The sartorius
Gracilis
Semitendinosus

81. Nerve Supply The femoral nerve The obturator nerve
The common peroneal nerve
The tibial nerve

82. Movements
The knee joint can flex, extend, and rotate

83. Screw Home Mechanism The extended knee is in locked position
medial rotation of the femur results in a twisting and tightening of all the major ligaments of the joint
The knee becomes a mechanically rigid structure
The cartilaginous menisci are compressed like rubber cushions between the femoral and tibial condyles

84. When the foot is firmly planted on the ground when a person is standing, the femur is medially rotated on the tibia to lock and stabilize the knee joint.
The foot is raised off the ground, the tibia may be laterally rotated on the femur to lock the knee joint.

85. Unlocking Or Untwisting Process
Before flexion of the knee joint can occur, it is essential that the major ligaments be untwisted and slackened to permit movements between the joint surfaces
This process is accomplished by the popliteus muscle, which laterally rotates the femur on the tibia.

86. Unlocking Or Untwisting Process
The menisci have to adapt their shape to the changing contour of the femoral condyles.
The attachment of the popliteus to the lateral meniscus results in that structure being pulled backward.

87. Locking and unlocking at the knee joint
Locking and unlocking at the knee joint. Shaded area = femur Solid line = tibia in extension Broken line = tibia in flexion

88. When the knee joint is flexed to a right angle, a considerable range of rotation is possible.
In the flexed position, the tibia can also be moved passively forward and backward on the femur.
This is possible because the major ligaments, especially the cruciate ligaments, are slack in this position

89. Important Relations Anteriorly: Posteriorly: Medially: Laterally:
The prepatellar bursa
Posteriorly:
The popliteal vessels
Tibial and common peroneal nerves
Lymph nodes
The muscles that form the boundaries of the popliteal fossa,
The semimembranosus
The semitendinosus
The biceps femoris
The two heads of the gastrocnemius
The plantaris
Medially:
Sartorius
Gracilis
Semitendinosus
Laterally:
Biceps femoris
Common peroneal nerve

90. STRENGTH OF THE KNEE JOINT
The strength of the knee joint depends on
The strength of the ligaments that bind the femur to the tibia
On the tone of the muscles acting on the joint.
The most important muscle group is the quadriceps femoris
It is capable of stabilizing the knee in the presence of torn ligaments.

91. KNEE INJURY AND THE SYNOVIAL MEMBRANE
If the articular surfaces, menisci, or ligaments of the joint are damaged, the large synovial cavity becomes distended with fluid.
The wide communication between the suprapatellar bursa and the joint cavity results in this structure becoming distended
The swelling of the knee extends three or four fingerbreadths above the patella and laterally and medially beneath the aponeuroses of insertion of the vastus lateralis and medialis, respectively.

92. ARTHROSCOPY
Arthroscopy involves the introduction of a lighted instrument into the synovial cavity of the knee joint through a small incision
This technique permits the direct visualization of structures, such as the cruciate ligaments and the menisci, for diagnostic purposes.

94. LIGAMENTOUS INJURY OF THE KNEE JOINT
Four ligaments ligament are commonly injured
The medial collateral ligament
The lateral collateral ligament
The anterior cruciate ligament
The posterior cruciate ligament
Sprains or tears occur depending on the degree of force applied.

95. Medial Collateral Ligament Injury
Forced abduction of the tibia on the femur can result in partial tearing of the MCL
At its femoral or tibial attachments.
Tears of the menisci result in localized tenderness on the joint line
Sprains of the MCL result in tenderness over the femoral or tibial attachments of the ligament.

96. Lateral Collateral Ligament Injury
Forced adduction of the tibia on the femur can result in injury to the lateral collateral ligament (less common than MCL).

98. Injury To The Cruciate Ligaments
When excessive force is applied to the knee joint.
Tears of the anterior cruciate ligament are common
The injury is always accompanied by damage to other knee structures; the collateral ligaments are commonly torn or the capsule may be damaged.
The joint cavity quickly fills with blood (hemarthrosis) so that the joint is swollen.
Examination of patients with a ruptured anterior cruciate ligament shows that the tibia can be pulled excessively forward on the femur
With rupture of the posterior cruciate ligament, the tibia can be made to move excessively backward on the femur

99. Injury To The Cruciate Ligaments
The stability of the knee joint depends largely on the tone of the quadriceps femoris muscle and the integrity of the collateral ligaments
Operative repair of isolated torn cruciate ligaments is not always attempted.
The knee is immobilized in slight flexion in a cast,
Active physiotherapy on the quadriceps femoris muscle is begun at once.
If the capsule of the joint and the collateral ligaments is torn, early operative repair is essential.

100. Arthroscopy
Intact ACL
Torn ACL

102. MENISCAL INJURY OF THE KNEE JOINT
Injuries of the menisci are common.
The medial meniscus is damaged much more
because of its strong attachment to the medial collateral ligament of the knee joint, which restricts its mobility.
when
the femur is rotated on the tibia, or the tibia is rotated on the femur
with the knee joint partially flexed
taking the weight of the body
The tibia is usually abducted on the femur, and the medial meniscus is pulled into an abnormal position between the femoral and tibial condyles
A sudden movement between the condyles results in the meniscus being subjected to a severe grinding force, and it splits along its length
"locked Knee”
When the torn part of the meniscus becomes wedged between the articular surfaces, further movement is impossible

103. MENISCAL INJURY OF THE KNEE JOINT
Injury to the lateral meniscus is less common
probably because it is not attached to the lateral collateral ligament of the knee joint
consequently more mobile.
The popliteus muscle sends a few of its fibers into the lateral meniscus
these can pull the meniscus into a more favorable position during sudden movements of the knee joint.

104. Types of Mensicus Tear? a) Normal meniscus b) Longitudinal Tear
c) Bucket Handle Tear
d) Radial Tear
e) Degenerative changes

105. Treatment of Meniscal Tears
Suture/ Repair
Debridement