The knee is the largest and most complicated joint in the human body. It consists of two condylar joints between the femur and tibia, as well as the patellofemoral joint. The stability of the knee relies primarily on soft tissues like ligaments rather than bony structure. The knee joint is divided into the medial and lateral compartments by the menisci. It contains several important ligaments like the ACL, PCL, MCL and LCL that provide stability. The muscles that act on the knee include the quadriceps, hamstrings, pes anserine group and iliotibial band.

1. PRESENTED BY:
DR.VIVEK CHANDA
MPT (SPORTS)

2.  The knee is the largest joint
in the human body and is
considered the most
complicated one.
 The knee consists of the
lateral and medial
compartments of the
tibiofemoral joint and the
patellofemoral joint.

3.  The stability of knee is based primarily on its soft
tissue constraints rather than on its bony
configuration.
 The knee condyler synovial joint. It has two condylar
jt. b/w the condyles of the femur and tibia, one
saddle jt. b/w the femur and the patella.
 The knee is also a complex jt. as the cavity is divided
by the menisci.

4. JOINTS IN KNEE COMPLEX
 Tibio-femoral joint
 Patello-femoral joint
PARTICIPATING BONES
• Femur
• Tibia
• Patella

5.  THE ARTICULAR SURFACES OF KNEE JOINTARE
AS FOLLOWING:
•THE CONDYLES OF FEMUR.
•THE PATELLA.
•THE CONDYLES OFTIBIA.

7. – A – Lateral Condyle
• Smaller radius of curvature
• Smaller in all dimensions
• Extends more anteriorly
– B – Medial Condyle
• Larger radius of curvature
• Extends more distally
– C – Intercondylar notch

8. •Anteriorly, the condyles are seperated by
Patello femoral Groove.
• Posteriorly, the condyles are separated by the
intercondylar notch.

10. – Medial Plateau
• Greater surface area
• Concave
• Circular shape
– Intercondylar Eminence
– Lateral Plateau
• Smaller surface area
• Convex
• Oval shape

11. Double condyloid knee joint is also referred
to as Medial & Lateral Compartments of
the knee.
 Double condyloid joint with 30freedom of
Angular (Rotatory) motion.
 Flexion/Extension
 Medial/lateral (int/ext) rotation
 Abduction/Adduction

13. Interface between articular
side of the patella and the
intercondylar(trochlear
groove) of the femur.
Main function of this joint is
transmission of forces.

14. Base- for quad tendon attachment
Apex - for patellar tendon attachment
Anterior surface
Posterior articular surface-convex in all direction
4-5 mm
Thick articular
cartilage
Odd facet
Vertical ridge
Large lateral
&small med facet

15. • As many as 13 Bursae have been
described around Knee Joint.
•The Four are Anterior
• Four are Lateral
• Four are Medial.

17.  These are Four in Numbers.
• Subcutaneous Prepatellar Bursa.
• Subcutaneous Infrapatellar Bursa.
• Deep Infra Patellar Bursa.
• Suprapatellar Bursa.

18.  There are Four Lateral Bursae.
• A Bursa deep to Lateral Head of
Gastrocnemius.
• A Bursa b/w Fibular Collateral
Ligament and the Biceps Femoris.
• A Bursa b/w Fibular Collateral
Ligament andTendon of Popliteus.
• A Bursa b/wTendon of Popliteus and
Lateral Condyle of theTibia.

19.  The Four Medial Bursae are as follows.
• A Bursa deep to the Medial head of
Gastrocnemius.
•TheAnserine Bursa.(Complicated)
• A Bursa deep to theTibialCollateral
Ligament.
• A Bursa deep to Semimembranosus

21.  Fibrous capsule
 Ligamentum patellae
 Medial & lateral collateral ligaments
 Oblique popliteal ligament
 Arcuate popliteal ligament
 Cruciate ligaments
 Menisci or semilunar cartilages
 Transverse ligament

23.  Fibrous capsule is very thin and is deficient anteriorly
where it is replaced by quadriceps femoris, patella and
ligamentum patellae.
 Femoral attachment- Attached about one and half cm
beyond the articular margins.
-Anteriorly - deficient
-Posteriorly- Intercondylar line
-Laterally- Encloses capsule of poplitius
 Tibial attachment- Attached about half to one cm
beyond the articular margins.
-Anteriorly- Margin of condyles of tibial tuberosity
-Posteriorly- Intercondylar ridge

24.  Common tendon of insertion of the quadriceps
femoris.
 7.5 cm long and 2.5 cm broad
 Attached above the apex of the patella and below
to the upper part of tibial tuberosity.
 Related to the superficial and deep infrapatellar
bursae and to the infrapatellar pad of fat.

26. Medial ligament-
 Attached superiorly to the medial epicondyle of
femur.
 Inserts into proximal tibia.
Lateral ligament-
 Approx 5 cm long.
 Attached superiorly to the lateral epicondyle of
femur.
 Inserts posteriorly to the head of fibula.

27. STRUCTURE FUNCTION MECHANISMOF INJURY
MCL
LCL
Resists
-valgus
-knee xtension
-extremes of axial
rotation(external
rotation)
Resists
-varus
-knee extension
-extremes of axial
rotations
1.Valgus producing force
with foot planted
2.Severe hyperextension of
the knee
1.Varus producing force
with foot planted
2.Severe hyperextension of
the knee

29. Oblique popliteal ligament-
 Expansion from the tendon of semimembranous
 Attached to the indercondylar line and lateral
condyle of the femur.
Arcuate popliteal ligament-
 Expansion from short lateral ligament
 Extends backwards from the head of fibula, arches
over the tendon of popliteus and attached to the
post. Intercondylar area of the tibia.

30. Provide multiple plane stability to the knee
most notably in the sagittal plane
Guide the natural arthrokinematics,especially
those related to the restraint of sliding
motions between the tibia and the femur
Contribute to proprioception of the knee

32. Two bands-
AMB(anteromedial band),
PLB (posterolateral band)
Attached below to the
anterior intercondylar area
of the tibia
Courses superiorly,
posteriorly & laterally;
attaches to the lateral
femoral condyle

33. STRUCTURE FUNCTION MECHANISMOF INJURY
ACL 1.Most fibers resist
extension
2.Resits extremes of
varus valgus and axial
rotation
1.Large valgus producing
force with foot planted
2.Large axial rotation
torque with the foot
firmly planted
3.Any combination of
above involving strong
quadriceps contraction
with the knee in full or
near full extension
4.Severe hyperextension
of the knee

34.  control the normal
rolling and gliding
movement of the knee
 posterior rolling of
femur tightens up ACL
which leads to anteror
translation

35. Anteromedial
bundle is taut in
both flexion &
extension, while the
posterolateral
bundle is taut on
extension only

37.  Two bands- ALB and PMB
 Attached below to the
posterior intercondylar area
of the tibia
 Courses superiorly,
anteriorly and medially;
attaches to the medial
femoral condyle

38. STRUCTURE FUNCTION MECHANISMOF INJURY
PCL 1.Most fibers resist knee
flexion
2.Resist extremes of varus
valgus and axial rotation
1.Falling on a fully flexed knee with
ankle fully plantarflexed
2. forceful posterior translation of
tibia(dashboard injury)or anterior
translation of femur,especially
while the knee is flexed
3.Large axial rotation or valgus
varus applied torque to the knee
with the foot firmly
planted,especially when the knee is
flexed
4.Severe hyperextension of the knee
causing a large gapping of the
posterior side of the joint

39.  Check femur from being
displaced anteriorly on the
tibia
 Tibia from being displaced
posteriorly on femlur.
 It tightens during flexion & is
injured much less frequently
than ACL.
 Near full extension the ALB are
lax and PMB are taut whereas
in 90-100 degrees of flexion
PMB are lax and ALB are taut.

40.  Sheets of fibrocartilage with a
thick peripheral convex border
and a thin inner concave
border which is attached to the
capsule
 Lateral meniscus is “O” shaped
 Medial meniscus is “C” shaped
and is thicker posteriorly than
anteriorly
 Ant. and post. Ends of menisci
are attached to tibia and are
referred to as Ant. and Post.
Horns.

41. • Peripheral thick part is vascular.
• Inner part is avascular and is nourished by synovial
fluid.
• Reduce the compressive stress across the
tibiofemoral joint & serve as shock absorber.
• Stabilising the joint during motion
• Lubricating the articular cartilage
• Providing proprioception
• Helping to guide knee arthrokinematics

42. Extension
 Meniscal migrate Anteriorly :
• Because of menisco-patellar ligament
 Flexion
 Menisci migrate posteriorly because of
• Semimembranosus attachment to medial
meniscus
• Popliteus attachment to lateral meniscus

43.  It connects the anterior ends of the medial
and lateral meniscus.

45. • FIVE GENICULAR BRANCHES OF POPLITEAL
ARTERY.
• DESCENDING GENICULAR BRANCH OF FEMORAL
ARTERY.
• DESCENDING BRANCH OF LATERAL
CIRCUMFLEX FEMORAL ARTERY.
•TWO BRANCHES OF ANTERIORTIBIAL ARTERY.
• CIRCUMFLEX FIBULAR BRANCH OFTIBIAL ARTEY.

46. FOLLOWING NERVES SUPPLY
THE KNEE JOINT:
• FEMORAL NERVE
THROUGH ITS BRANCHES
TOVASTI(ESPVASTUS
MEDIALIS)
• SCIATIC NERVETHROUGH
GENICULAR BRANCHES OF
TIBIAL AND COMMON
PERONEAL N.
• OBTURATOR NERVE
THROUGH ITS POSTERIOR
DIVISION.
• INFRAPATELLAR BRANCH

47. MUSCLESOF KNEEAND IT’SFUNCTIONS
•Anterior – Quadriceps
• Posterior – Hamstrings
•Medially – Pes anserine group
•Laterally – Illiotibial band/TFL

48. Anterior Musculature
• Rectus femoris
•Vastus lateralis
•Vastus intermedius
•Vastus medialis

49. Rectus Femoris
• O: AIIS
• I:Tibial tuberosity
via infrapatellar
tendon
• N: Femoral
• A: Knee extension,
hip flexion

50. Vasti Muscles
• O:
VL – Greater trochanter,upper ½
of linea
aspera;
VI – Anterolateral upper 2/3 of
femur,
lower ½ of linea aspera
VM –Distal intertrochanteric line,
medial
linea aspera
• I:Tibial tuberosity via
infrapatellar
tendon
• N: Femoral
• A: Knee extension

51. Posterior Musculature
• Biceps femoris
• Semimembranosus
• Semitendinosus
• Popliteus
• (Gastrocnemius)

52. Biceps Femoris
• O: Long – ischial tuberosity;
Short – lateral linea
aspera, upper 2/3 of
supracondylar line
• I: Fibular head, lateral tibial
plateau
• N: Long – tibial
Short – common peroneal
• A: Knee flexion,Hip
extension (long
H.), Knee external rotation

53. Semimembranosus
• O: Ischial tuberosity
• I: Posteromedial of
medial
tibial plateau
• N:Tibial
• A: Knee flexion,Hip
extension,Knee
internal
rotation

54. Semitendinosus
• O: Ischial tuberosity
• I: Medial tibial flare
(pes
anserine)
• N:Tibial
• A: Knee flexion,
Hip extension,
Knee internal rotation

55. HAMSTRINGS
Weakness of hamstring may result in significant loss of knee flexion strength
difficulty bending and lifting.
Tightness of hamstring may result in limitation in knee extension ROM when the
hip is flexed.
POPLITEUS
Origin- Lateral femoral condyle
Insertion- Posteriomedial tibia
Nerve-Tibial
An important rotator and flexor of knee joint.
It is a key to the knee.(it provide internal rotation torque that help
mechanically to unlock the knee).
Dynamically stabilises both lateral and medial sides of the
knee(the strong intracapsular tendon of the popliteus provide
significant resistance to a varus load applied to the knee, stabilise
medially by limiting excessive external rotation.

56. MEDIAL ROTATORS OF THE KNEE
Pes Anserine Muscles
• Sartorius (most anterior)
• Gracilis (middle)
• Semitendinosus (most
posterior)
1)Sartorius
• O: ASIS
• I: Anteromedial tibial
flare (pes anserine)
• N: Femoral
• A: Hip flexion,
Hip abduction,
Hip external rotation

57. Gracilis
• O: Symphysis pubis,
inferior
ramus of pubic bone
• I: Anteromedial tibial
flare (pes anserine)
• N: Obturator
• A: Hip adduction,
Hip flexion,
Knee flexion

58. Iliotibial Band/TFL
• O: Anterior superior iliac
crest
• I: Anterolateral tibia at
Gerdy’s tubercle
• N: Superior gluteal
• A: Hip flexion,
Hip abduction,
Hip internal rotation

59. STABLIZERS OF KNEE
Classification of supporting structure of knee
 Functional
 Static stabilizer
 Dynamic stabilizer
 Location
 Medial joint compartment
 Lateral joint compartment

61. STATIC STABILIZERS
It include the passive structures, such as:
 Capsule
 Ligaments
• Meniscopatellar ligament
• PF ligament
• MCL & LCL
• ACL & PCL
• Oblique poplitial &
• Transverse ligament

62. DYNAMIC STABILIZERS
It includes following muscles & aponeuroses:
 Quadriceps femoris
 IT band
 Extensor retinaculum
 Poplitius
 Pes anserinus
 Hamstrings
 Gastrocnemius

63. MEDIAL JOINT STABILIZERS
Structure includes :
 Medial patellar retinaculum,
 MCL,
 Oblique poplitial ligament &
 PCL

64. LATERAL JOINT STABILIZERS
The structure included in static & dynamic
stabilization of knee :
 IT band
 Biceps femoris
 Popliteus
 LCL
 Meniscofemoral arcuate
 ACL
 Lateral patellar retinaculum

65. ROLE OF VMO AS A KNEE STABILIZER
 The pull of the rectus femoris
and vastus intermedius is parallel
to the shaft of femur. The pull of
vastus lateralis is lateral is lateral
to the femur. The patellar tendon
pulls the patella distally. The sum
of these forces is a proximal and
lateral pull on the patella.
 Fiber arrangement of VMO
makes it ideally suited to
provide stability

67. Q (QUADRICEPS)ANGLE

68.  It estimates the lateral pull of the
quadriceps muscle.
 Q angle is a function of location
of tibial tuberosity rather than
the shaft of tibia.
 Therefore, torsional deformities
of the tibia and femur and rotary
malalighnments of foot can alter
the Q angle without changing the
valgus alighnment of knee
 An increased Q angle indicates an
increase lateral pull on the patella
and appears to increase the risk
of anterior knee pain.

69. Q Angle increases due
to:
a) Femoral anteversion
b) External tibial torsion
c) Laterally displaced tibial
tubercle
d) Genu valgum

71. SCREW-HOME MECHANISM
Screw home rotation has been described as an
conjunct rotation, it is mechanically linked(or
coupled) to the flexion and extension
kinematics and cannot be performed
independently.
Locking of the knee in full extension requires
about 10 degrees of external rotation during
last 30 degrees or more of extension.

72. During last 30 degrees of extension
Automatic rotation(tibial external rotation in
open chain) and (femoral internal rotation in
closed chain motion)
Locking of the knee joint(which is a stable and
closed packed position of knee joint)

74. POPLITEUS MUSCLE:THE “KEY TO THE
KNEE”
• As the extended and locked
knee prepares to flex, the
popliteus provides an
important internal rotation
torque that helps to
mechanically unlock the
knee.
• Because of the muscle’s
enhanced leverage to
initiate internal rotation of
th the knee, it has been
referred to as “key to the
knee”.

75. References
• Joint Structure and Function: A
Comprehensive Analysis, Fourth Edition,
Cynthia C. Norkin, 2005
• Joint Structure and Function: A
Comprehensive Analysis, Third Edition, Cynthia
C. Norkin
• Clinical Kinesiology and Anatomy, Fourth
Edition, Lynn S. Lippert, 2006

76. THANK YOU!