described about the ligament testing,meniscal repair and types of iknee instability

1. KNEE INSTABILITY
PRESENTOR: DR.PUNITH KUMAR PC
MODERATOR: DR.SRINIVASA.N
VIMS ,BALLARY

2. Introduction
Knee is a hing joint but actually it is more complicated than
that, because in addition to flexion and extension its motion
has a rotatory component.
Knee is one of the most frequently injured joints because of
its anatomic structure, its exposure to external forces and the
functional demands placed on it.
Much emphasis has been placed on the ligaments of knee,
without the supporting action of the associated muscles and
tendons, the ligamets are not enough to maintain knee
stability

3. Structure of knee
The structure around the knee has been classified into
three broad categories:
• Osseous Structures
• Extra- articular Structures
• Intra- articular Structures

4. Osseous Structures
• Femoral Condyles
• Tibial Condyles
• Patella

6. Femoral Condyles
• They are two rounded prominences that are
eccentrically curved. Anteriorly these condyles are
some what flattened which creats a large surface for
contact and weight transmission.
• The condyles project a very little in front of femoral
shaft but markedly behind.
• Anteriorly patello- femoral groove ( trochlear groove )

7. • Posteriorly inter-condylar fossa.
• Articular surface of medial condyle longer while the
lateral condyle is broader .
• The long axis of lateral condyle is along the sagittal
plane whereas the medial condyle is about 22 degree
angle to the sagittal plane.

10. Tibial Condyles
• Proximal end of tibia forms two condyles or plateus
that articulates with femoral condyles.
• They are separated by intercondular eminence with its
medial and lateral inter condular tubercles.
• Anterior and posterior parts of intercondular eminence
are the areas that serve as attachment sides for the
cruciate ligaments and menisci.

11. • The articular surface of knee are not congruent.
• Medial side of tibia meets the femur like a wheel on a flat surface,
whereas the lateral side is like a wheel on a dome.

12. Patella
• It is a triangular shaped sesamoid bone that is wider at
proximal pole than at the distal pole.
• Its articular surface has large lateral articular surface
and small medial surface divided by a vertical ridge.
• During flexion and extension patella moves 7cm-8cm
in relation to the femural condyles.

13. In full extension – only the lateral facet articulates with the femur
In full flexion – medial facet sustains more pressure

14. Extra Articular Structures
• Musculotendinous units
• Capsule
• Collateral ligaments
• Synovium

15. Musculotendinous Units
Quadriceps Muscle
1) Rectus Femoris
2) Vastus Lateralis
3) Vastus Medialis
4) Vastus Intermedialis

16. Attachments Of Quadriceps Femoris
MUSCLE ORIGIN INSERTION
RECTUS FEMORIS • AIIS
• SUPERIOR
ACETABULAR
RIM
• ANTERIOR EDGE
OF PROXIMAL
PATELLA
VASTUS LATERALIS • GREATER
TROCHANTER
• LINEA ASPERA
( LATERAL)
LATERAL PATELLA/
TIBIAL TUBERCLE
VASTUS
INTERMEDIALIS
PROXIMAL
FEMORAL SHAFT
POSTERIOR EDGE
OF PROXIMAL
PATELLA
VASTUS MEDIALIS INTER
TROCHANTERIC
LINE , LINEA
ASPERA(MEDIAL)
TIBIAL TUBERCLE

18. Hamstring Muscles
• Semitendinosus
• Semimembranosus
• Biceps Femoris Long And Short Head

19. Attachments Of Hamstrings
MUSCLE ORIGIN INSERTION
SEMITENDINOSU
S
ISCHIAL
TUEROSITY
(inferomedial upper
aspect)
PROXIMAL
MEDIAL TIBIA
SEMIMEMBRANOS
US
ISCHIAL
TUBEROSITY
( superolateral
impression )
POSTERIOR
MEDIAL TIBIAL
CONDYLE
BICEPS FEMORIS :
LONG HEAD
ISCHIAL
TUBEROSITY
(inferomedial upper
area)
HEAD OF FIBULA
(lateral aspect)
BICEPS FEMORIS :
SHORT HEAD
LINE
ASPERA,SUPRACO
NDYLAR LINE
FIBULA,LATERAL
TIBIA

20. Semimembranosus Expantion
It has five distal expansion:
1. Oblique popliteal ligament which runs on the posterio
medial aspect of the tibia obliquely and laterally upwards
towards the insertion of lateral gastrocnemius head.
2. Tendinous attachment is to the posterior capsule and
posterior horn of medial meniscus.
3. Deep head continues medially along the flare of tibial
condyle and inserts beneath the superficial medial
collateral ligament just distal to joint line.

21. 4. Direct head attaches to the tubercle on the posterior aspect of the
medial condyle of tibia.
5. The distal portion continues distally to form a fibres expansion
over the popliteus and fuses with the periosteum of medial tibia.

22. Gastrocnemius:
Most powerful calf muscle spans the posterior aspect of knee and inserted on
the posterior aspect of medial and lateral femoral condyles.

23. Popliteus
• It has three origins the strongest of which is from the lateral
femurol condyle, others are from fibular popliteo fibular
ligament and from the posterior horn of lateral meniscus.
• The arcuate ligament is not a separate ligament but is a
condensation of fibres of origin of politeus.

24. •Stabilize knee by resisting lateral rotation of tibia.
•Provide rotatory stability and aids pcl in preventing forward
dislocation of femur .

25. Medial Extensor Expansion
• Its a distal expansion of vastus medialis aponeurosis .
• It attaches along the medial border of patella and
patella tendon and distally inserts into the tibia.
• It functions as medial tracking support of patella in
patello femoral groove.
• Contraction of vastus medialis helps tighten the
anterior portion of medial capsular ligaments.

26. Lateral Extensor Expansion
• Its is an extension of vastus lateralis attaching to the
iliotibial band which help tense this band as the knee
extends the ilio tebial band moves forward.
• Imbalance between medial and lateral retinacular
structures is often present in patellar subluxation and
dislocation.

27. CAPSULE
• It is a sleeve of fibrous tissue extending from the
patella and patella tendon anteriorly to the medial,
lateral and posterior expanses of the joint.
• The menisci are attached firmly at the periphery to the
capsule more medially and less laterally.
• The capsule is reinforced by the collateral ligaments
and the medial and lateral hamstring muscles, as well
as by the popliteus muscle and the ilio tibial band
posteriorly.

29. Medial Collateral Ligament
• Two parts – superficial,deep and oblique part.
• Oblique part – fan shaped from medial condyle to
posterior half of medial tibial condyle.
• Inserts on medial meniscus and tibial plateau .
• Glides forward in extension and posteriorly in flexion.
Function :
• Protect against valgus and external rotatory stress.
• Stabilize meniscus.

31. Lateral Collateral Ligament
• Attaches to the lateral epicondyle of femur proximally
and the head of fibula distally .
• Seperated from lateral meniscus by popliteus.
Function
• Stabilize the knee against varus stress in extension.
• Also resist external rotation.

33. Intra-articular Stuctures
The principal intra articular structures of importance are
a) Medial and lateral menisci.
b) Anterior and posterior cruciate ligaments.

34. Functions Of Menisci
Numerous functions have been assigned to the menisci.
Some are known and some are hypothetical.
1. Distribution of joint fluid.
2. Nuitrition
3. Shock asbsorbtion
4. Deepening of the joint
5. Stabilisation of the joint
6. Load baring function

35. Funtions of cruciates
1. The cruciates function as stabilizers of the joint and axis
around which rotatory motion , both normal and
abnormal occurs.
2. They restrict the forward and backward motion of the
tibia on the femur and assist in the control of both medial
and lateral rotation of tibia on the femur.
3. External rotation of the tibia produces an unwinding of
the ligaments, internal rotation produces a winding up of
the cruciate ligaments.

36. Stabilisers Of Knee
Static Stabilisers:
• Tibio femoral collateral ligaments
• Medial and lateral meniscus
• Topography of the articular surfaces
• Loads across the articular surfaces
Dynamic Stabilisers:
• Quadriceps
• Hamstrings
• Cruciate ligaments
• Gastrocnemius, popliteus and pes anserinus

37. Nicholas classification for knee
stabilisers
Central complex
•ACL, PCL
•Medical meniscus
•Lateralmeniscus
Medial complex
•MCl,
Posteromedial
capsule
•Semimembranou
muscle,
Pesanserinus
Lateral complex
•Iliotibial tract,
lateral
collateral ligament
•Popliteus
muscle,biceps
femoris muscle

38. Meniscal Injury
• Meniscal tears are the most common soft tissue injury of
the knee joint.
• Traumatic meniscal tears most commonly occur in young,
active people during twisting sports such as football and
basketball.
• Degenerative tears commonly occur in patients with
osteoarthritis, although the exact incidence and
prevalence are not known.

39. MEDIAL MENISCUS
• C shaped structure forming 3/5 of
thering.
• Anterior horn attached to the tibia
anterior to the intercondylar
eminence to the anterior cruciate
ligament.
• Posterior horn anchored
immediately in front of the
attachment of posterior cruciate
ligament posterior to the
intercondylareminence.

40. MEDIALMENISCUS...
• Peripheral border attached to
the medial capsule and
through the coronary ligament
to the upper border of tibia.
• Most of the weight borne on
the posterior portion of the
meniscus.

41. LATERAL MENISCUS
• The posterior horn receives
anchorage to the femur via the
ligament of Wrisberg and
ligament of Humphrey and from
fascia covering the popliteus
muscle.
• The tendon of the popliteus
separates the posteriolateral
periphery of the lateral meniscus
from the joint capsule and
fibular collateral ligament.

42. Miller, Warner and Harner
classification
a. Red-Red-fully within vascular
area.
b. Red-White-at the border of
vascular area
c. White-White within the
avascular area

43. Mechanism of Injury
Turning or twisting of the loaded joint may trap the menisci between
the jointand tearthe meniscus.
MEDIAL MENISCUS
⚫ Internal rotation of femur over tibia with knee in flexion forces the
posteriorsegmentof medial meniscus towards thecentreof the joint.
⚫ The posterior horn may be trapped in this position bysudden extension
of knee.

44. LATERAL MENISCUS
• Vigorous external rotation of femur while the knee is flexed
displace the posterior half of the lateral meniscus toward the centre
of the joint.
• During sudden extension of the knee, an anterioposterior distracting
force tends to straighten the cartilage and imposes a strain on the
medial concave rim, which tears transversely and obliquely.

45. Classification
O’Connor Classification:
Based on the type of tear found
at surgery
• Longitudinal tear
• Horizontal
• Oblique
• Radial tears
• Variations which includ flap tears,
complex tears and degenerative
tears.

46. Diagnostic Tests
McMurray’s Test-sensitivity 70% and specificity 71%
• McMurray first described his test in 1942 and published in
paper entitled “ Semilunar Cartilage” with the patient
supine and knee flexed.
• Examiner can check the medial meniscus by palpating the
postero medial margin of the joint with one hand while
grasping the foot with the other hand.
• With the flexed knee leg is externally rotated as far as
possible and the knee is slowly extended.

47. • As a femur passes over a tear in the meniscus a click may be
heard or felt.
• Lateral meniscus is checked by palpating the postero lateral
margin of the joint, internally rotating the leg as far as
possible and then slowly extending the knee.
• A negative result of this test does not rule out a tear

48. Lateral Meniscus Testing
Medial Meniscus Testing

49. Apley’s Compression Test -sensitivity 60% and specificity 70%
• With the patient in prone position knee in 90 degree
flexed position
• Anterior thigh is fixed against the examining table
• The foot and the leg are then pulled upwards to
distract the joints and rotated to place rotational strain
on ligaments.
• With the knee in same position the foot and the leg are
pressed downwards as the joint is slowly extended.

50. • If menisci has been torned popping and pain
localized to the joint line may be noted.

51. SQUAT TEST
⚫Consistsof several repetitionsof full squatwith
the feet and leg alternately rotated as thesquat is
performed
⚫Pain in the internally rotated position suggests
injury to the lateral meniscus
⚫Pain in theexternal rotation suggests injury to the
medial meniscus

52. Thessaly test
⚫ Clinician holds the patient's
outstretched hands for support,
while the patient stands flat-
footed.
⚫ Knee flexed initially to 5 degree
and then to 20 degrees and then
asked to rotate their body and knee
three times, internally and
externally.
⚫ The test is positive if the patient
experience medial or lateral joint line
discomfort and may have sense of
locking or catching.
⚫ Joint line tenderness alone stands
with the sensitivity of 63% and
specificity of 77%.

53. Imaging Studies
Radiograph- antero posterior,
lateral and intercondylar notch
view should be routine.
It is essential to exclude loose
bodies, osteochondritis and other
derangements of the knee.

54. MRI
 Great value in the diagnostic evaluation of meniscal tears.
 The accuracy of meniscal tears – 98% for medial meniscus and
90% for lateral meniscus.

55. ARTHROSCOPY
⚫Is the diagnostic procedure to detect the meniscal injuries.
⚫ Accuracy of diagnostic arthroscopy is 97%.

56. Non Operative Treatment
Management
Cylindrical cast or knee immobilizer for 4-6 wks
Crutch walking with touch-down weight bearing
permitted when the patient gains active control of the
extremity in the cast progressive isometric exercise in cast.
At 4 to 6 weeks, the immobilization discontinued, and the
rehabilitative exercise program for the muscles around
the hip and knee intensified.

57. Non Operative Treatment …
Most important aspect of non-operative treatment:-
-Restoration of the power of the muscles around the injured knee to a
level comparable with that of the opposite knee.

58. SURGICAL TREATMENT
1. Meniscectomy
-By arthrotomy
-By arthroscopy
2. Meniscal repair
-By arthrotomy
-By arthroscopy
3. Meniscal transplantation
-With autografts, allograft, prosthetic scaffolds.

59. EXCISION OF MENISCI
i) Partial meniscectomy:
-Only the loose, unstable
fragments excised.
-Stable and balanced peripheral
rim preserved

60. EXCISION OF MENISCI...
ii) Subtotal Meniscectomy:
-Requires excision of portion of
peripheral rimof meniscus
-Most of the anterior horn and a
portion of middle 3 rd of the
meniscus are not resected.
iii) Total Meniscectomy:
Done when meniscus is detached
from its peripheral menisco-synovial
attachment and intrameniscal
damage and tearsareextensive.

61. Open Menisectomy
⚫EXCISION OF MEDIAL MENISCUS
• Using single anteromedial incision:

62. Open Menisectomy…
EXCISION OF MEDIAL MENISCUS...
⚫ Using two incision: HENDERSON
• An additional
• Posteromedial incision
• Permits easierand complete detachmentof
posterior horn
• Posteriorincision is made 5 cm parallel and
slightly posterior to the tibial collateral ligament.

63. Open Menisectomy…
• EXCISION OFTHE LATERAL MENISCUS

64. Open Menisectomy…
AFTER TREATMENT
• Compression bandage.
• Knee immobilized in extension with posterior plaster splint or
with a knee immobilizer for 5-7 days.
• Quadriceps exercises.
• When the good muscular control is achieved, patient
allowed to walk with crutches and with partial weight
bearing.

65. Arthroscopic Repair of Torn Menisci
• CRITERIA
 Location : Within 3 mm of periphery
 Stability :
 Partial thickness
 Full thickness- oblique and vertical tears less
than 10 mm with inability to displace the central
portion with a probegreaterthan 3mm

66. Arthroscopic Repair Of Torn Menisci…
 Tearpattern : peripheral , vertical and longitudinal tears
repaired.
Bucket handle, flap, degenerative, complex, radial tearsare
excised
 Patient age : less than 50 yrs
 Chronicity : Acute tears less than 8 weeksold have better
healing potential
 Ligament stability : ACL deficiency mustalso becorrected
simultaneously to prevent instability.

68. Recent Advances
• Enhancement of meniscal healing
• Arthroscopic repair of torn meniscus using fibrin clot
• Meniscal replacement with
- allograft meniscus
- autograft fascial material
- synthetic meniscus
• Biologic tissue scaffolds

69. Common Ligament Injury
 The anterior cruciate ligament (ACL)
 The medial collateral ligament (MCL)
 The lateral collateral ligament (LCL)
 The posterolateral corner (PLC)
 The posterior cruciate ligament (PCL)

70. Anterior Cruciate Ligament
Anatomy
• The ACL originates at posteromedial aspect of the
lateral femoral condyle.
• Wide tibial insertion at the lateral aspect of the anterior
tibial spine.
• The ACL has two fiber bundles.
• The anteromedial.
• Posterolateral bundles.
• Which provide varying tension from flexion through
extension.

71. Functions
• Primary restraint against anterior tibial translation.
• Provides rotational stability, especially in extension.

72. ACL - Mechanism of Injury
Injury to the knee ligaments is typically the result of
1. A non contact change in direction
2. Twisting injury
3. Landing from a jump.
The patient often describes a “pop” that is felt or heard at injury The
appearance of swelling (hemarthrosis) within a few hours

73. ACL Examinations
Examinations
• TheAnterior drawer test
• The Lachman Test
• The Pivot Shift Test
• Novel Tests

74. ACL – Anterior drawer test-sensitivity 20% , specificity 88%.
Procedure
• Patient with patient supine position
• The hip flexed at 45° / knee flexed at 90°
• The foot is fixed to the table - often by sitting on
it
• The clinician applies an anterior force to the
proximal tibia, palpating the joint line for
anterior translation.
Increased anterior translation indicates ACL
insufficiency.
Grading: <2mm –insignificant
2-5mm -nearly normal
>5mm- abnormal

75. ACL -Lachman Test- sensitivity 86% , specificity 91%.
It was designed to overcome three identified limitations of the
anterior drawer test
1. Acute effusion that often precludes flexion to 90°.
2. Protective spasm of the hamstring muscles that can prevent
anterior translation of the tibia.
3. The articulation of the relatively acute convexity of the
posterior medial femoral condyle and the posterior horn
of the medial meniscus that buttresses and prevents
anterior translation of the tibia.
These limitations can lead to false-negative findings.
Best negative predictive value overall better test to rule out and
rule in ACL tear.

76. Procedure
The Lachman test is typically done with the knee flexed 20° to 30°.
The examiner places one hand laterally on the patient’s thigh to stabilize
the femur.
while the other hand grasps the proximal and more subcutaneous medial
tibia and applies anterior stress.
The test is positive
1. In the presence of anterior translation
2. Asoft or mushy end point.
3. When theACL is intact, the end point is hard
Grading:
Grade - 1 Feel of positive test
Grade - 2 Visible anterior translation
Grade - 3 Passive subluxation of tibia woth the patients supine.
Grade- 4Ability of the patients to actively subluxate the proximal
tibia.

77. With the knee in slight flexion (20°to 30°)
• The hamstring loses mechanical advantage by
simple geometry.
• The relatively flat weight-bearing portion of the
medial femoral condyle more easily glides over
the posterior horn of the medial meniscus.

78. ACL - Grading -Lachman test
Apositive Lachman test is used to grade an injury as
• Grade - 1 ( anterior translation 1 - 5 mm compared with
the uninjured knee),
• Grade - 2 (anterior translation 6 - 10 mm compared with
the uninjured knee),
• Grade - 3 (anterior translation >10 mm compared with the
uninjured knee).

79. ACL - PivotShift Test- sensitivity 18-48% , specificity 97-99%.
• Anterior subluxation of the lateral tibial plateau ( Internal rotation and
full extension of the tibia) Then spontaneous reduction as the knee
flexes to 30°to 40°.
•The reduction is achieved by the pull of the iliotibial band with clunk
(passes posterior to the axis of the knee)
•Best positive predictive value.

80. Procedure
The patient is supine with the knee extended.
It is essential that the patient is relaxed for this test.
The examiner grasps the heel with one hand,
pointing the foot upward or with internal rotation
with the other hand placed over the fibular head
The examiner applies a valgus force through the knee,
which impinges the subluxated tibial plateau, preventing too easy a reduction.
While the clinician maintains this valgus force and slight internal rotation, then
the knee is slowly 30° flexed.
As it passes 30 to 40°of flexion, the reduction will occur and is often identified by the patient as
the instability symptom.

81. ACL – Novel test
The lever sign test/Lelli test
Placing a fist under the calf of the affected
leg; this acts as a fulcrum, a downward
force is applied to the quadriceps.
Failure of the heel to rise off the table
indicates anACL rupture.
The lever sign was shown to be more
sensitive than other tests (Lachman,
anterior drawer, pivot shift) for diagnosis
of acute and partialACL tears.

82. Medial Collateral Ligament -MCL
Mechanism of injury
Can be injured when a contact or noncontact valgus stress is applied to
the knee.

83. MCL injury examination
Grading of MCLInjury
• Fetto and Marshall developed a classification system for valgus laxity
measured at 0°and 30°
• grade I denoting tenderness with stability at both angles
• grade II denoting laxity at 30°
• grade III denoting laxity at both 0°and 30°
• One advantage of this system is that it follows the biomechanics of the medial
knee: at 30°,
the sMCLis the primary restraint to valgus stress
• whereas at 0°the posterior oblique ligament and posterior medial corner
complex are the primary restraints. Currently, no classification system has
been validated or is consistently used for outcomes reporting

84. MCL Injury examination
Valgus Stress Test
Should perform the valgus stress test -
The knee fully extended
Knee slightly flexed (approximately 20°to 30°),
which relaxes the posterior capsule and helps to isolate the MCL.
When valgus stress is applied
1. Laxity,
2. The amount of medial joint opening
3. The quality of the end point
A great deal of normal variation in laxity exists, so it is essential to
compare the laxity of the injured knee with that of the contralateral
knee.
Valgus instability in full extension indicates tearing of the dMCL,
sMCL, and at least one cruciate ligament.

85. LCL Injury
Varus stress test
• Gross laxity under various load can be assessed by varus stress test
the LCL is best isolated at 30°flexion the varus stress test should
likewise be performed at both 0°and 30°flexion.
• Laxity at 0°indicates more severe injury, including injury to not
only the LCL, but also to the PLC and/or associated cruciate
ligaments.

86. Posterior Cruciate Ligament
Anatomy
•The PCL runs posterolaterally towards
the central posterior aspect of the tibia,
Inserting on its own fovea
approximately 1 cm distal to the joint
line.
•Just posterior to the posterior horn of the medial
meniscus.
•Its femoral insertion is a broad, vertically oriented
footprint at the anterolateral aspect of the medial
femoral condyle
•The PCL is made up of the anterolateral and the
posteromedial fiber bundles.

87. PCL Injury
Function-
The PCL is the primary restraint to posterior tibial translation.
Mechanism of Injury-
• Common mechanism is striking the tibia on the dashboard
during a motor vehicle collision.
• Isolated PCL injuries also are seen in athletic competition when the
athlete falls directly onto the knee with the foot plantar flexed, allowing
the tibial tuberosity to strike the ground.
• The injury can be caused by both hyperflexion and hyperextension

88. PCL injury
Isolated PCL injuries are often undiagnosed because the classic popping
sound at injury is not as distinctive and the swelling is not as severe as
that associated withACL injuries, and recurrent instability is rare.
Examinations for PCL injury
1. The posterior drawer test and
2. The quadriceps active test
Each test is performed with 45° hip flexed to and the knee flexed to 90°.
In this position, there is a loss of the normal anterior tibial step-off with a
PCL injury.
Typically, when the knee is flexed to 90°, the anteromedial tibial plateau
extends 1 cm anteriorly beyond the medial femoral condyle

89. PCL Examination
Posterior Sag Sign
In a PCL-deficient knee placed in
the resting 90°flexion position.
The tibia is subluxated posteriorly
The posterior sag sign can be used
to assess for loss of anterior tibial
step off, without any manipulation
of the joint.
Sensitivity – 79%
Specificity - 100%

90. PCL Examination
Posterior Drawer Test
The posterior drawer test essentially
adds a posteriorly directed force to the
posterior sag sign.
The foot is positioned in neutral rotation
The examiner then immobilizes the foot
(often by sitting on it), places the thumbs
on the tibial plateau, and pushes
posteriorly on the tibia to assess for
increased translation compared with the
contralateral side.

91. PCL Examination
Quadriceps Active Test
Patient is in supine position
Hip flexed to 45 degree.
The patient is asked to slightly
contract the quadriceps In a PCL-
deficient knee placed in the
resting 90°flexion position, the
tibia is subluxated posteriorly, but
activation of the quadriceps
causes the patellar tendon to
reduce the tibia.
This observable reduction
constitutes a positive test
result.
1. Sensitivity -54%
2. Specificity – 97%

92. Tests forAnterolateral Rotatory Instability
Slocum’sAnterior Rotatory Drawer Test
• This is a modification of theAnterior drawer test.
• The patient is in Supine position and the knee flexed to 90 deg.
• Keep the foot in 30 deg of internal rotation and perform
the anterior drawer test.
• The test is positive if there is anterior subluxation of the
lateral tibial condyle.

93. Lateral Pivot Shift test of Macintosh.
• It is used to detect the anterior subluxation of the lateral tibial
condyle.
• The patient in supine position.
• Fully extend the knee with foot in internal rotation.
• Apply a valgus stress.
• In this position if there is instability the tibia is in subluxed
position.

94. • As the knee is flexed past the 30 degree the iliotibial
band passes posterior to the centre of rotation of the
knee and provides a force that reduces the lateral
tibial plateau on the lateral femoral condyle.
• An isolated tear of the anterior cruciate ligament
produces only minimal subluxation, whereas greater
subluxation indicates lateral complex or
semimembranosus deficiency.

95. Jerk test of Hughston and Losee
• With the patient in supine position knee is flexed to 90 deg
with the tibia in internal rotation.
• The knee is then gradually extended with the valgus stress
applied.
• The test is positive if the lateral tibia subluxes anteriorly in
the form of sudden jerk at about 30 deg of flexion.

96. TestsforAnteromedial Rotatory insability
Slocum’s Anterior Rotatory Drawer Test
• In this the patient is in supine position and the knee flexed
to 90 degree.
• With the foot in 15 deg of external rotation perform the
anterior drawer test.
• Excessive excursion of the medial tibial condyle suggests
positive test.

97. T
ests for Posterolateral Rotatory Instability
The Hughston’s Posterolateral Drawer test.
• With the patient in supine position the knee is flexed to little less
than 90 deg and the foot in external rotation.
• Apply backward pressure on the tibia.
• Excessive travel on the lateral side is indicative of
posterolateral instability(posterior cruciate and lateral
complex).

98. External Rotation Recurvatum Test.
• The patient is in supine position.
• The examiner stands at the end of the couch.
• Now lift the legs holding the great toes on both sides.
• The test is positive if knee falls into external rotation,varus
and recurvatum.

99. Reverse Pivot Shift Sign Of Jakob, Hassler And Staubli.
• With the patient in supine position the knee is flexed to 90 degree
and foot externally rotated,which subluxes the tibial condyle
posteriorly.
• Now apply a valgus force to the knee and extend the knee fully.
• If the test is positive the posteriorly subluxed tibia reduces at about
20 degree.

100. Tibial External rotation test or Dial Test.
• This test can be done with the patient in supine or prone position,better
with the patient in prone position.
• It is done with the knee in both 30 & 90 deg.
• Grasp the foot and the degree of external rotation of the foot is
measured relative to the axis of the femur.
• It is measured noting the foot thigh angle.In addition the tibial
plateaus are palpated to determine whether the external rotation is
caused by lateral tibial plateau moving posteriorly or medial tibial
plateau moving anteriorly.

101. • A10 deg difference between the two knees is considered positive.
• If the test is positive only at 30 deg of knee flexion it indicates isolated
PLC injury.
• If the test is positive at both 30 & 90 degree, then it indicates injury to
both PLC and PCL.

102. Posterolateral Instability
Standing Apprehension Test
To detect posterolateral instability of the knee.
The patient stands with the knee slightly bent and internally rotates
the torso away from the leg, producing an internal rotation of the
femur on the tibia.
If the patient experiences apprehension or instability, the test is
considered positive. The authors considered the test to be 100%
sensitive, but this estimation was based on a small patient cohort,
and all of the patients had positive dial tests at 90°knee flexion,
indicating injury to the PCL and PLC.

103. Classification Of Knee Joint Instability
• Traumatic disruption of knee ligaments often results in
complex and multiplane instabilities.
• This specific classification of each instability depends
on the movement of tibia in relation to the femur
during stress testing.

104. Classification
One plane instability (Simple or Straight):
a) One plane medial
b) One plane lateral
c) One plane posterior
d) One plane anterior
Rotatory Instability
a) Anterio medial
b) Anterio lateral
c) Posterio lateral
d) Posterio medial
Combined Instability
a) Anterio lateral-anterio medial rotatory
b) Anterio lateral-posterio lateral rotatory
c) Anterio medial-posterio medial rotatory

105. One Plane Instability
1) One Plane medial instability
• Then knee joints opens on the medial side. That is the
tibia moves from the femur.
• It is a major instability and indicates disruption of medial
collateral ligament, medial capsular ligament, ACL,
posterior oblique ligament and medial portion of posterior
capsule.
• It is detected only when the knee is tested in 30 degree of
flexion indicating tear limited to medial compartments.

106. 2) One plane lateral instability
• Then knee joints opens on the lateral side, that is the tibia moves
from the femur.
• It indicates disruction of lateral capsular ligament, lateral collateral
ligament, biceps tendon, iliotibial band, arcuate popliteus complex,
popliteofibular ligament, ACL and PCL
• Instability is detected only with knee in 30 degree of flexion

107. 3) One plane posterior instability
• When the tibia moves posteriorly on the femur during posterior
drawer test.
• It indicates disruption of PCL, arcuate ligament complex ,posterior
oblique ligament complex.

108. 4) One plane anterior instability
• The tibia moves anteriorly over the femur during anterior drawer test
in neutral position.
• It indicates the disruption of ACL, lateral capsular ligament, medial
capsular ligament.
• Severe grades of instabilities are accompanied with central or
peripheral ligamentous deficiencies , so therfeore most are
accompanied with rotatory instabilities as well

110. Rotatory instabilites
1) Anteromedial Rotatory Instability :
• With stress testing the medial plateau of the tibia rotates
anteriorly and externally as the joint opens on the medial
side.
• It implies disruption of medial capsular ligament, medial
collateral ligament , posterior oblique ligament and the
ACL.

111. 2) Anterolateral Rotatory Instability :
• It is detected at 90 degree flexion of knee.
• The tibia displaces anteriorly and the lateral plateau rotates
forwards in relation to the femur at 90 degree of flexion with
excessive lateral opening of joint .
• It implies disruption of lateral capsular ligament ,arcuate
ligament , ACL

112. 3) Posterolateral rotatory instability:
• With stress testing the lateral tibial plateau rotates posteriorly in
relation to the femur, with lateral opening of the joint.
• It implies disruption of popliteal tendon, arcuate ligament ,lateral
capsular ligament , and stretching or loss of integrity of PCL.
• The posterolateral corner of the tibia drops off the back of the femur
and lateral opening of the joint is detected while performing external
rotation recurvatum test and reverse pivot shift test

113. 4) Posteromedial rotatory instability :
• With stress testing the medial tibial plateau rotates posteriorly in
reference to the femur with medial opening of the joint.
• It implies disrutption of medial collateral ligament ,medial capsular
ligament, posterior oblique ligament, PCL, medial portion of
posterior capsule with stretching or major injury to
semimembranosus insertion and ACL may be injured.

115. Combined Rotatory Instability
1) Combined Anterolateral-Anteromedial :
• It is a most common combined instability
• The result of antrerior drawer test with the tibia in nuetral positio is
markedly positive with both tibial condyles displaced anteriorly
• The displacement is exaggerated when the tibia is externally rotated
and diminished but usually not obliterated the test is done with tibia
internally rotated.
• Antrolateral rotatory instability tests are positive.
• Varus and valgus stress test show instability of varying degree.

116. 2) Combined anterolateral-Posteriolateral:
• The lateral tibial plateau rotates in a posterior direction as the
external rotation-recurvatun test is performed, and there is excessive
forward displacement of lateral tibial plateau on the femur when the
antrolateral rotatory instability tests are performed.
• Lateral instability is great with disruption of most of the structures on
lateral side of knee, aswell as ACL with occasional stretching of PCL.

117. 3) Combined anteriomedial-Posteriomedial:
• The knee opens on the medial side and the tibia may rotate
anteriorly when tested, with further testing the tibia roatates
posteriorly, dropping off the posteriomedial corner of the
joint.
• All medial structures including the semimembranosus
complex, are disrupted in combination with ACL and most
likely PCL.

118. Treatment Consideration
First Degree Sprains :
• Rest ,ice and a compression bandage are usually all that are
required
• Patient can return to their functions and activities within a few
days

119. Second Degree Sprain :
• In these part of ligament has been torn and although the remaining
untorn portion may stabilise the knee to routine stress testing .
• If these patients are permitted to return promptly to full activity
especially in sports complete disrutption of ligament is real
possibility .
• These patients are best treated with controlled motion brace ,allowing
full, protected motion for 4-6 weeks.
• Recovery usually can be expected with no residual laxity once the
rehabilitation is completed .
Third Degree Sprains :
They require operative treatment depending on factors such as age,
general health,associated injury and activity demands .

120. THANK YOU