The document outlines the anatomy and physiology of the knee joint, provides guidance on evaluating knee injuries through history, physical examination including special tests for ligament stability, and outlines specific knee injuries. It describes relevant bony landmarks, ligaments, tendons and nerves as well as the functional compartments and motions of the knee. Evaluation of knee injuries involves focused history on pain location and mechanism of injury followed by physical examination of range of motion, effusion, tenderness and special tests like anterior drawer and McMurray's tests.

1. KNEE INJURIES
Ahmed AL Jabri

2. outlines
• Relevant anatomy
• History ( focused )
• Knee examinaBon ( special tests )
• To xray or not ?
• Specific injuries ( interac0ve format ) .

3. ANATOMY/physiology
• The knee is the largest and most complicated
joint in the body .
• MoBon at the knee is a complex interacBon of
flexion, extension, rotaBon, gliding, and
rolling.
• modified‐hinge diarthrodial synovial joint .
• 3 bones , 2 meniscus, 4 main ligaments.
• Great stability mainly depends on the integrity
of the ligamentous structures

4. Which of the following is False ?
1. FuncBonally, the knee joint can be divided into three
compartments: patellofemoral, medial Bbiofemoral,
lateral Bbiofemoral.
2.Found within the popliteal space are the
popliteal artery, the popliteal vein, and the
peroneal and Bbial nerves.
3.The lateral and medial femoral epicondyles
serve as important sites of origin for the medial
and lateral collateral ligaments, respecBvely
4. 1&2
5. None of the above

5. Which of the following is False ?
1. FuncBonally, the knee joint can be divided into three
compartments: patellofemoral, medial Bbiofemoral,
lateral Bbiofemoral.
2.Found within the popliteal space are the
popliteal artery, the popliteal vein, and the
peroneal and Bbial nerves.
3.The lateral and medial femoral epicondyles
serve as important sites of origin for the medial
and lateral collateral ligaments, respec0vely
4. 1&2
5. None of the above

8. Regarding popliteal artery ?
• represents the direct conBnuaBon of the femoral
artery beyond the adductor hiatus
• descends across the posterior aspect of the knee joint
and terminates at the level of the Bbial tubercle.
• it divides into the anterior and posterior Bbial arteries
at the level of the Bbial tubercle
• It is anchored firmly at the proximal and distal ends of
the popliteal fossa .
• Blood supply to the knee joint comes from the
popliteal artery via the geniculate arteries
• All of the above

9. Regarding popliteal artery ?
• represents the direct conBnuaBon of the femoral
artery beyond the adductor hiatus
• descends across the posterior aspect of the knee joint
and terminates at the level of the Bbial tubercle.
• it divides into the anterior and posterior Bbial arteries
at the level of the Bbial tubercle
• It is anchored firmly at the proximal and distal ends of
the popliteal fossa .
• Blood supply to the knee joint comes from the
popliteal artery via the geniculate arteries
• All of the above

10. HISTRORY

11. IniBal Assessment: History
• Injury history
• Pain
• Clicking
• Locking
• Giving way
• Instability
• Swelling

12. Injury history
• High‐energy trauma without knee swelling should
raise the suspicion of disrupBon of the joint
capsule with expulsion of joint fluid and
hemorrhage into the thigh or lower leg .
• Lower energy injuries are more commonly
associated with meniscal tears, patella
dislocaBons, and less severe ligament injuries.
• acBviBes with twisBng and turning are associated
with anterior cruciate tears and meniscal
pathology.

13. Focused History QuesBons
• Onset of Pain
– Date of injury or when symptoms started
• Loca0on of pain
– Anterior
– Medial
– Lateral
– Posterior

14. Focused History QuesBons 2
• Mechanism of Injury ‐helps
predict injured structure
– Contact or noncontact injury?
• If contact, what part of the knee was
contacted?
– Anterior blow?
– Valgus force? Valgus alignment = distal
– Varus force? segment deviates lateral
with respect to proximal
segment.
– Was foot of affected knee planted on
the ground?

15. Focused History QuesBons
• Injury‐Associated Events
– Pop heard or felt?
– Swelling acer injury (immediate vs delayed)
– Catching / Locking
– Buckling / Instability (“giving way”)

16. Historical Clues to Knee Injury
Diagnoses
Noncontact injury with “pop” ACL tear
Contact injury with “pop” MCL or LCL tear, meniscus
tear, fracture
Acute swelling ACL tear, PCL tear, fracture,
knee dislocation, patellar
dislocation
Lateral blow to the knee MCL tear
Medial blow to the knee LCL tear
Knee “gave out” or “buckled” ACL tear, patellar dislocation
Fall onto a flexed knee PCL tear

17. Common Symptoms
Factor Meniscal Cruciate MCL/ Chronic
LCL Instability
Swelling + +++ - ++
delayed early absent recurrent
Locking yes no no yes
Clicking yes no no yes
Giving yes yes no yes
way

18. EXAMINATION
•
1. Outline areas of tenderness.
2. Note whether any effusion is present.
3. Check for range of moBon, valgus stress at 0 and 30 degrees of flexion, and
varus stress at 0 and 30 degrees of flexion.
4. Evaluate the patellar and extensor mechanism of the knee (quadriceps and
patella tendons).
5. Perform Lachman's , anterior drawer, posterior drawer, and pivot shic tests
to check for anterolateral rotatory instability and further delineate possible injury
to the anterior cruciate ligament.
6. Perform meniscal examinaBon with McMurray's and Apley's tests.

19. 1, quadriceps
tendiniBs; 2,
prepatella
bursiBs, patella
pain; 3,
reBnacular pain
acer patella
subluxaBon; 4,
patella
tendiniBs; 5, fat
pad tenderness;
6, Osgood‐
Schlamer
disease (Bbial
tubercle pain);
7, meniscus
pain; 8,
collateral
ligament pain;
9, pes anserine
tendiniBs
bursiBs

20. STABILITY TESTING
• Anterior Drawer Test.
• Lachman's Test.
• Posterior Drawer Test.
• McMurray's Test.
• Apley's Test.
• Pivot Shi.
• Collateral Ligament Stress Test.

21. Anterior Drawer Test
• The anterior drawer test is a test for disrupBon
of the anterior cruciate ligament (ACL) .
• HOW TO DO IT ? VIDEOsknee injury.flv

22. Anterior Drawer Test
• A posiBve test is defined as the ability of the Bbia to
move forward relaBve to the femur compared with the
other knee.
• False‐negaBve findings may occur from an effusion
prevenBng knee flexion to 90 degrees, hamstring
muscle spasm caused by pain, or insufficient force
applied during performance of the test
• A false‐posiBve test can be caused by posterior cruciate
ligament (PCL) insufficiency, which allows the Bbia to
slip back on the femur, showing an abnormal amount
of displacement when pulled forward

23. Lachman's Test
• currently the best clinical test for determining
the integrity of the ACL ;
• RELIABLE when there is an acute hemarthrosis
• the knee flexed 20 to 30 degrees with one hand
grasping the thigh and stabilizing it. The Bbia is
pulled forward with an anteriorly directed force
VIDEOsKnee Exam Lachman Test.flv

24. Lachman's Test: grades of instability
1. 1+ (0 to 5mm more displacement than the
normal side),
2. 2+ (5 to 10mm),
3. or 3+ (>10mm).

25. Lachman's Test: limitaBons
• PCL must be intact for the test to be valid
• false‐negaBve tests include hamstring spasm,
meniscal tears, and third‐degree MCL tears with
posterior medial extension.
• Specific limitaBons of Lachman's test include
difficulty quanBtaBng the amount of anterior
translaBon and inability to limit moBon of the
femur.
• Lachman's test also may be diffi culmo perform if
the examiner's hands are small relaBve to the
paBent's thigh.

26. Posterior Drawer Test
• The posterior drawer test remains the “gold
standard” for evaluaBng PCL injury
• How to do it ?
VIDEOsPosterior Drawer Test ‐ Knee.flv

27. Posterior Drawer Test
Posterior displacement of the Bbia more than 5
mm, or a “soc” endpoint, indicates injury to
the PCL. A normal knee should exhibit no
significant posterior excursion

28. McMurray's Test
• McMurray's test is used to idenBfy meniscal
tears
• How to do it ? VIDEOsMcMurrays test.flv

29. McMurray's Test
1. A posiBve test occurs when, with the other
hand, a “clicking” sensaBon is felt along the
joint line or the paBent experiences pain
during internal and external rotaBon.
2. By twisBng the leg into internal rotaBon, the
posterior segment of the lateral meniscus is
tested.
3. External rotaBon tests the posterior segment
of the medial meniscus

30. Apley's Test
1. Apley's test also aids in diagnosing meniscal
tears.
2. With the paBent prone, the knee is flexed 90
degrees, and the leg is internally and externally
rotated with pressure applied to the heel.
3. Downward pressure eliciBng pain suggests
meniscal pathology.
4. The pain should be relieved with distracBon of
the knee and rotaBon of the leg back to a
neutral posiBon.

31. Pivot Shi
• It should be done carefully as it may exacerbate
the iniBal injury.
• Used to detect anterolateral rotatory instability
associated with an injury to the ACL or lateral
capsular structure.
• UNCOMFORTABLE, Usually done pre‐operaBvely
• How to do it ?
VIDEOsPivot shic test.flv

32. Collateral Ligament Stress Test
The collateral ligament stress test is used to test
the integrity of the MCL and LCL.
Valgus and varus tesBng at both 0 and 30
degrees of flexion?

33. It is imperaBve that the injured knee be stress tested to detect
ligamentous injury. Which of the following statements describing
the stress tests for the knee is FALSE?
1. Lachman's test: amempt to move the parBally flexed Bbia anteriorly and
posteriorly on the femur; laxity indicates cruciate injury.
2. Apply varus and valgus stress with the knee in 20‐30 degrees flexion.
Detects medial or lateral ligament injury UNLESS the cruciates are intact.
3. Apply varus and valgus stress in full extension. Instability indicates injury
to the cruciates as well as the medial or lateral ligaments.
4. Posterior sag of the upper Bbia or posterior drawer sign: rupture of the
posterior cruciate.
5. Anterior drawer sign: rupture of the anterior cruciate.
6. Lateral pivot shic: one hand applies a valgus force to the extended knee
with the thumb on the fibular head and the other hand internally rotates
the foot while flexing the knee. Near 30 degrees, the lateral Bbia will
palpably reduce with lateral and anterior cruciate instability.

34. It is imperaBve that the injured knee be stress tested to detect
ligamentous injury. Which of the following statements describing
the stress tests for the knee is FALSE?
Apply varus and valgus stress with the knee in
20‐30 degrees flexion. Detects medial or
lateral ligament injury UNLESS the cruciates
are intact.
(In slight flexion the cruciates are unstressed
and varus/valgus stress can detect isolated
medial or lateral ligament injury. In full
extension the cruciates stabilize the knee to
varus/valgus stress )

35. All of the physical examinaBon findings are consistent with a
meniscus knee injury EXCEPT:
1. Joint line tenderness.
2. Knee or groin pain, locking, and limited excursion of the
joint.
3. Effusion that tends to develop rapidly acer the injury.
4. Apley test: flex the knee 90 degrees and compress and
rotate the Bbia on the condyles; pain implies a torn
posterior horn of the medial meniscus.
5. PosiBve McMurray test: With the thumb and fingers
palpaBng the lateral and medial joint lines, extend the
knee while rotaBng the foot externally; repeat while
rotaBng the foot internally with the opposite hand. Pain,
locking and grinding are suggesBve of a meniscus injury.

36. All of the physical examinaBon findings are consistent with a
meniscus knee injury EXCEPT:
1. Joint line tenderness.
2. Knee or groin pain, locking, and limited excursion of the
joint.
3. Effusion that tends to develop rapidly aer the injury.
4. Apley test: flex the knee 90 degrees and compress and
rotate the Bbia on the condyles; pain implies a torn
posterior horn of the medial meniscus.
5. PosiBve McMurray test: With the thumb and fingers
palpaBng the lateral and medial joint lines, extend the
knee while rotaBng the foot externally; repeat while
rotaBng the foot internally with the opposite hand. Pain,
locking and grinding are suggesBve of a meniscus injury.

37. Radiographic Evalua0on
to xray or not

38. All of the following are component of
Omawa Knee Rule, except ?
1. the paBent is 55 years or older
2. there is tenderness at the head of the fibula
3. there is isolated tenderness of the patella
4. the paBent is unable to flex the knee to 90º
5. there is knee effusion
6. the paBent is unable to take four steps both
at the Bme of the injury and at the Bme of
the evaluaBon

39. All of the following are component of
Omawa Knee Rule, except ?
1. the paBent is 55 years or older
2. there is tenderness at the head of the fibula
3. there is isolated tenderness of the patella
4. the paBent is unable to flex the knee to 90º
5. there is knee effusion
6. the paBent is unable to take four steps both
at the Bme of the injury and at the Bme of
the evaluaBon

40. Omawa Knee Rule
• More than $1 billion is spent on emergency
radiography of the knee each year in the
United States, with 90%‐92% of these studies
showing no fracture .
• The rule is almost 100% sensiBve and 97%
specific .

41. Pimsburgh Knee Rule in blunt knee
trauma
states that radiography is necessary only if the
paBent fell or sustained blunt trauma to the
knee, and either of two condiBons is present:
• (1) age younger than 12 or older than 50 or
• (2) inability to walk four full weight‐bearing
steps in the emergency department.

44. TRUE OR FALSE ?
• In Trauma The tradiBonal “knee series” is
anteroposterior, lateral, and sunrise view .

45. FALSE
CORRECT: In Trauma The tradiBonal “knee
series” is anteroposterior, lateral, and tunnel
views
Tunnel” views, which image the intercondylar
notch, are used to detect Bbial spine fractures
and loose bodies within the notch

46. Specific injuries

48. Knee disloca0on requires immediate orthopedic
consulta0on due to the high incidence of
complica0ons, including all of the following EXCEPT:
• unstable ligament injury
• meniscus injury
• popliteal artery injury
• sciaBc nerve injury
• Bbial nerve injury
• peroneal nerve injury

49. Knee disloca0on requires immediate orthopedic
consulta0on due to the high incidence of
complica0ons, including all of the following EXCEPT:
• unstable ligament injury
• meniscus injury
• popliteal artery injury
• scia0c nerve injury
• Bbial nerve injury
• peroneal nerve injury

50. KNEE DISLOCATION
• 50%‐60% are anterior
• popliteal artery injury is most commonly
associated with posterior dislocaBons
• Peroneal nerve injury is the most common
major neurological problem associated with
knee dislocaBon.
• WHEN TO ORDER AN ANGIOGRAPHY ?

54. Bi‐parBte patella ( normal variant)

57. Transverse and avulsion fractures of the patella are most ocen due to
excessive quadriceps tension rupturing the patella, whereas comminuted
fractures are caused by direct trauma.
Which of the following statements describing the treatment of patella
fractures is FALSE?
1. nondisplaced transverse fracture: ankle to groin
cylinder cast
2. transverse fracture displaced >2‐3 mm or large
avulsion: wire fixaBon
3. minor comminuBon with minimal separaBon:
meBculous alignment and wire fixaBon of the
fragments
4. comminuted fracture: excision of bone
fragments and direct anastomosis of the
quadriceps tendon to the patellar ligaments

58. Transverse and avulsion fractures of the patella are most ocen due to
excessive quadriceps tension rupturing the patella, whereas comminuted
fractures are caused by direct trauma.
Which of the following statements describing the treatment of patella
fractures is FALSE?
1. nondisplaced transverse fracture: ankle to groin
cylinder cast
2. transverse fracture displaced >2‐3 mm or large
avulsion: wire fixaBon
3. minor comminu0on with minimal separa0on:
me0culous alignment and wire fixa0on of the
fragments
4. comminuted fracture: excision of bone
fragments and direct anastomosis of the
quadriceps tendon to the patellar ligaments

61. Segond fracture
• represents a bony avulsion of the lateral Bbial plateau
• an important marker of ACL disrupBon

64. Tibial Plateau Fractures
• Because the iniBal injury is usually a valgus stress
with an abducBon force on the leg, 55% to 70% of
condylar fractures involve the lateral plateau
• The most impt aspect of the iniBal examinaBon is the
neurovasc status
• Displaced fractures of the lateral condyle may
produce peroneal nerve paralysis in addiBon to injury
to the anterior Bbial artery

65. four factors determine the prognosis of
Bbial plateau fractures:
1. degree of arBcular depression,
2. extent and separaBon of the condylar fracture lines,
3. diaphyseal‐metaphyseal comminuBon and
dissociaBon,
4. integrity of the soc Bssue envelope (i.e., open versus
closed)

66. Management
• As a rule, accurate reducBon and prolonged non–
weight bearing are the guidelines to be followed in
Bbial condylar fractures.
• Main techniques
– compression dressing, closed reducBon and casBng, skeletal
tracBon, and open reducBon with internal fixaBon
• In general, with more severely depressed #s, operaBve
treatment has bemer results than nonoperaBve
therapy; however, no universal agreement exists on the
acceptable amount of arBcular depression

70. Osteochondri00s Dissecans
• The disorder is found mainly in adolescents and results in a
segment of arBcular carBlage and subchondral bone
becoming parBally or totally separated from the underlying
bone
• The management of these paBents is based on the stability
of the osteochondral fragment and the maturity of the
skeleton
– If the epiphyses are open, conservaBve treatment with
protecBve weight bearing usually results in healing of the lesion.
– Once the epiphyses are closed, the prognosis for healing is
guarded. If the fragments are detached, the loose fragments
require surgery for removal or fixaBon. Protected range of
moBon with non–weight‐bearing acBvity for 6 to 10 weeks is
generally advised

71. A boy has fallen from a low limb of a tree or from his bicycle
onto his right knee and fractured the anterior Bbial spine
(intercondylar eminence) of the Bbia. Which of the following
statements concerning his injury is FALSE?
1. His exam will reveal a posiBve drawer sign and
Lachman's test, and possibly laxity of the medial
collateral ligament on valgus stress.
2. His x‐ray will reveal a fracture of the Bbial spine.
3. Usually, surgical treatment with screw or wire
fixaBon is preferred.
4. Usually closed treatment (if posiBoning can
achieve anatomic reducBon) is preferred;
otherwise open or arthroscopic fixaBon may be
required.

72. A boy has fallen from a low limb of a tree or from his bicycle
onto his right knee and fractured the anterior Bbial spine
(intercondylar eminence) of the Bbia. Which of the following
statements concerning his injury is FALSE?
1. His exam will reveal a posiBve drawer sign and
Lachman's test, and possibly laxity of the medial
collateral ligament on valgus stress.
2. His x‐ray will reveal a fracture of the Bbial spine.
3. Usually, surgical treatment with screw or wire
fixa0on is preferred.
4. Usually closed treatment (if posiBoning can
achieve anatomic reducBon) is preferred;
otherwise open or arthroscopic fixaBon may be
required.

75. Segond
fracture
and Bbial
spine
avulsion
fracture

76. • CT image of
knee
demonstra
Bng Segond
fracture
and Bbial
spine
avulsion
fracture

77. Fracture of the Tibial Spine
(intercondylar eminence)
• The spine has two prominences: the medial and
lateral tubercles
• The ACL and the anterior horns of both the
medial and the lateral menisci amach in the
anterior intercondylar fossa. The PCL and the
posterior horns of the menisci amach in the
posterior intercondylar fossa.
• Radiographic evaluaBon should include standard AP and
lateral views, but a tunnel view provides a clearer look at
the intercondylar area and may be necessary to confirm
the diagnosis

78. intercondylar eminence:
CLASSIFICATION
– Type I involves incomplete avulsion of the
Bbial spine without displacement.
– Type II, there is an incomplete avulsion
with minimal displacement of the
anterior third of the fracture fragment,
but the posterior porBon remains
adherent.
– Type III is characterized by complete
separaBon of the fragment from its
fracture bed and has a higher associated
rate of collateral ligament injuries and
peripheral meniscal tears
• Type IIIA, fractures with complete
displacement,
• Type IIIB, fractures with displacement and
rotaBon

79. THANK YOU