1. KNEE EVALUATIONS

2. Quick Facts Patellofemoral Joint (PFJ)
Variations in PFJ loading during OKC and CKC activities
PFJ loading increases:
with increased flexion in CKC
with increased extension in OKC
PFJ Loading
Walking
0.3 x body weight
Ascending Stairs
2.5 x body weight
Descending Stairs
3.5 x body weight
Squatting
7 x body weight

3. History MOI - Previous history Pain (levels, types, descriptors)
Position of lower extremity at time of injury (?foot planted, knee extended)
Previous history
Pain (levels, types, descriptors)
Unusual sounds/sensations “pop, clicking, snapping”
Chronic vs. acute
Location of pain “inside the knee”
Surface
Shoes
Type of activity at time of injury
Painful to walk up/down stairs; any clicking, catching
Did it swell immediately, slowly?
Is the swelling located in the knee or in a pocket?

4. Observation Bilateral comparison
Gait (limp, walking on toes, do they not want to extend knee, do they keep the knee stiff)
Swelling (girth measurements)
Discoloration
Deformity (squinting patellae, “Frog-eyed” patellae, Patella alta, Patella baja)
Genu valgum, genu varum, recurvatum
Musculature – defined/mushy

5. Q-angle
The quadriceps angle (Q-angle) is the angle formed between a line drawn through the tibial tuberosity and the center of the patella and another line drawn from the anterior superior iliac spine (ASIS) of the pelvis through the center of the patella.

6. Q-angle Knee in extension Knee in 90 degrees flexion
Normal males: 13 degrees
Normal females: 18 degrees
Knee in 90 degrees flexion
Both genders: 8 degrees

7. Structural Alignment
Genu Varum (Bowlegged)
Genu Valgum (knock kneed)

9. Boney Palpation Tibia Pes Anserine Hamstrings Fibula Medial joint line
Tibial tuberosity
Tibial Condyles (medial + lateral)
Fibula
Head
Medial joint line
Medial collateral ligament
Lateral joint line
Lateral Collateral Ligament
“Windows”
Medial & Lateral Femoral Epicondyles
Pes Anserine
Hamstrings
Semitendinosus tendon
Semimebranosus
Biceps femoris tendon
Quadriceps muscle group
Rectus Femoris
Vastus Lateralis
Vastus Intermedius
Vastus Medialis Oblique
Iliotibial band
Popliteal fossa
Gastrocnemius heads
Patella
Patellar tendon

10. Boney Palpation Tibia Fibula Medial & Lateral Femoral Epicondyles
Tibial tuberosity
Tibial Condyles (medial + lateral)
Fibula
Head
Medial & Lateral Femoral Epicondyles
Patella

11. Surface Anatomy Patella (A) Femur (B) Tibia (C,E – tuberosity)
Joint Line (D)
Fibula (F)

12. Boney Anatomy Bony Anatomy Lower Leg Upper Leg Patella Tibia Fibula
Bears most of the weight
Fibula
Attachment place for muscles & ligaments
Upper Leg
Femur
Patella

13. Patella Sesamoid bone Imbedded in quadriceps & patella tendon
Serves similar to a pulley for improving angle of pull (results in greater mechanical advantage in knee extension)

14. Tendons + Ligaments Medial joint line Medial collateral ligament
Lateral joint line
Lateral Collateral Ligament
“Windows”
Pes Anserine
Semitendinosus tendon
Gracilis tendon
Sartorius tendon
Semimebranosus tendon
Biceps femoris tendon
Quadriceps Tendon
Iliotibial band
Patellar tendon

15. Internal Knee Anatomy

16. Internal Knee Anatomy Medial Meniscus Lateral Meniscus
Anterior Cruciate Ligament
Posterior Cruciate Ligament
Articular Cartilage

17. Menisci

18. Bursae & Fat Pad of the Knee

19. Cruciate Ligament Movement

20. Anatomy – Soft Tissue Quadriceps – Hamstrings – Popliteus
Rectus femoris
Vastus lateralis
Vastus intermedius
Vastus medialis oblique
Hamstrings –
Biceps femoris
Semitendinosus
Semimembranosus
Popliteus
Popliteal fossa
Gastrocnemius + Soleus
Tibialis Anterior

21. Muscles

22. Quick Facts Tibiofemoral Joint (TFJ) Normal ROM Closed Pack Position
Flexion degrees
Extension 0 degrees
Closed Pack Position
Full extension with ER
Loose Packed Position
25 degrees of flexion

23. Knee Movements

24. Screw Home Mechanism
Locking mechanism as the knee nears its final extension degrees
Automatic rotation of the tibia externally (approx. 10 degrees) during the last 20 degrees of knee extension
Femoral condyles are a different size
Medial has larger surface area
The tibia glides anteriorly on the femur. As knee extends, the lateral femoral condyle expends its articular distance. The medial articulation continues to glide, resulting in external rotation of the tibia utilizing the lateral meniscus as the pivot point.
ACL & PCL are rotary guides
Forms a close-packed position for the knee joint

25. Special Tests Myotomes and Dermatomes Valgus Stress test
Varus Stress Test
Tinel Test
Apley
McMurray
Anterior Drawer
Lachmans
Posterior Drawer
Godfrey’s 90/90
Posterior Sag
Patellar Apprehension Test
Clark’s Sign

26. Stress/Special Tests Check for swelling Check ROM
Check integrity of ligaments & joint stability
Valgus, Varus, Lachman’s, Anterior/Posterior Drawer, Godfrey’s Test/Posterior Sag Test,
Check integrity of meniscus
McMurray’s, Apley’s Compression/Distraction, Duck Walk,
Check integrity of patella
Patellar Apprehension, Q Angle, Clarke’s Sign,

27. Special Tests

28. Anatomy of the ACL 3 strands
Anterior medial tibia to posterior lateral femur
Prevent anterior tibial displacement on femur
Secondarily, prevents hyperextension, varus & valgus stresses

29. Biomechanics of the ACL
Most injuries occur in Closed Kinetic Chain
Least stress on ACL between degrees of flexion
Anteromedial bundle tight in flexion & extension
Posterior lateral bundle tight only in extension

30. ACL Tears Most common mechanisms
Contact:
CKC with foot ER w/ valgus stress
Hyperextension
direct hit on the posterior tibia
Non-Contact:
Most common
Due to sudden deceleration
Sudden landing, cutting, or pivoting
Patient will c/o “buckling” or “giving away”, typically will hear and/or feel a “pop”

31. Why perform an MRI after ACL injury?
Diagnostic Imaging
Why perform an MRI after ACL injury?

32. Anterior Lachmans Position: Action: Positive Findings: Supine
Knee flexed to 20 – 30 degrees
Proximal hand on Femur above the patella, distal hand on Tibia just below Tibial Tuberosity
Action:
Apply anterior force to the tibia with the distal hand while stabilizing the femur with the proxmial hand
Positive Findings:
Anterior Cruciate Ligament Sprain
Joint opening up

33. Anterior Drawer Position: Action: Positive Findings
Hip flexed to 45o; knee 90o
Foot on table in neutral
Examiner sits on foot w/ B hands behind the subject’s proximal tibia and thumbs on the tibial plateau
Action:
Apply anterior force to the proximal tibia, feeling the hamstrings for tightness
Positive Findings
Anterior Tibial Displacement
Anterior Cruciate Ligament Sprain

35. PCL Biomechanics Functions: Taut at 30 degrees of flexion
Primary stabilizer of the knee against posterior movement of the tibia on the femur
Prevents flexion, extension, and hyperextension
Taut at 30 degrees of flexion
posterior lateral fibers loose in early flexion

36. Posterior Cruciate Ligament
Two bundles
Anterolateral, taut in flexion
Posteromedial, taut in extension
Orientation prevents posterior motion of tibia
PCL larger & stronger than ACL
CSA % larger
CSA AL 2x PM
Consider associated role of posterolateral complex when discussing PCL
LCL
Popliteus Complex
Arcuate Ligament
Posterior Lateral Capsule

37. PCL Injuries Very rare in athletics, usually due to MVA
Due to hyperextension, hyper-flexion, or the tibia being forced posteriorly on the femur
Only 33% related to sports
Isolated PCL Injuries unusual
Assess other ligaments
Avulsion Injuries
Mid-Substance Tears
Many PCL injuries are unreported (less common than ACL, less debilitating than ACL (easier to cope), minimal effusion & minimal pain)
Parolie & Edson reported that 2% of NFL predraft players were PCL deficient
3-20% of all ligamentous injuries to knee (Miyasaka & Daniel 1991 vs. Parolie & Bergfled 1986)
37% (Fowleer & Messieh 1987) of incidence in knees with hemarthrosis
Geisler & Whipple 1993 found 27% of acute PCL injuries & 49% of chronic PCL injuries also involved the meniscus 37

38. Posterior Drawer Test Position: Action: Positive Findings
Hip flexed to 45o; knee 90o
Foot on table in neutral
Examiner sits on foot w/ B hands behind the subject’s proximal tibia and thumbs on the tibial plateau
Action:
Apply posterior force to the proximal tibia
Positive Findings
Posterior Tibial Displacement
Posterior Cruciate Ligament Sprain

39. Godfrey’s 90/90Test Position: Action: Positive Findings
Hip flexed to 90o; knee 90o
Examiner holds onto both heels
Action:
Look for posterior translation of the tibia
Positive Findings
Displacement of the Tibia
Posterior Cruciate Ligament Sprain

40. Posterior Sag Test Position: Action: Positive findings:
Lie on table Knee flexed to 90o; Hip flexion 45o
Action:
Subject actively flexes Quads while hip remains in 45o
Look for a posterior translation of the Tibia in relation to the Femur
Positive findings:
Posterior Cruciate Ligament Sprain

41. MCL Biomechanics
Primary role is to prevent against a valgus force and external rotation of the tibia
Throughout Full Range of Motion:
Both fibers are taut in full extension
Anterior fibers are taut in flexion
Posterior fibers are taut in mid range

42. MCL Sprains Typically due to valgus forces in CKC
Radiographs useful in demonstrating avulsion fractures only, while MRI will demonstrate location of MCL injury & associated tissue injury
Typically due to valgus forces in CKC
Foot typically in neutral or externally rotated
Most frequently injured ligament in the knee
Usually no joint effusion unless deep portion affected since primarily located outside the joint capsule 42

43. Valgus Stress Test Position: Action: Positive Findings
0o and 30o
Proximal hand on Lateral joint line
Distal hand on the lower leg
Action:
Apply medial force to lateral joint line; and lateral force to distal tibia
Positive Findings
Medial Collateral Ligament Sprain

44. LCL Biomechanics
Primary role is to protect from varus forces and external rotation of the tibia, assists in 2° restraint for anterior and posterior tibial translation
Throughout Range of motion:
Is taut during extension
Loose during flexion
Especially after 30° of flexion

45. LCL Sprains
Typically due to varus forces, especially in CKC position with leg adducted and tibia internally rotated
Usually occur during contact sports
Typically has limited joint effusion since it is located outside of the joint capsule

46. Varus Stress Test Position: Action: Positive Findings
0o and 30o
Medial hand on Medial joint line
Action:
Apply lateral force to medial joint line; and medial force to distal tibia
Positive Findings
Lateral Collateral Ligament Sprain

47. Meniscal Functions
Deepens the articulation and fills the gaps that normally occur during the knee’s articulation
Primary Functions
Load distribution
Joint Stability
Shock Absorption
Secondary Functions
Joint Lubrication
Articular Cartilage Nutrition
Proprioceptive Feedback

48. Mechanism of Injury Trauma Degenerative Changes Compression
Rotational Force
Valgus Force
Usually Combination of Forces
Degenerative Changes
Greater than 30 years old
No PMHX required
Often due to MOI that “seemed harmless” at time
Noyes, 2002 states 60% of meniscal injuries associated with ACL injury

49. Apley Compression Distraction Position: Action: Positive findings:
Prone
Knee flexed to 90o ; foot dorsiflexed
Action:
Stabilize the femur with examiner’s knee
Push down on ankle/lower leg and rotate
Positive findings:
Pain = Meniscus
No Pain = Ligament involvement
Distraction
Position:
Prone
Knee flexed to 90o ; foot dorsiflexed
Action:
Stabilize the femur with examiner’s knee
Pull up on ankle/lower leg and rotate
Positive findings:
No pain = Meniscus
Pain = Ligament involvement

50. McMurray Position: Action: Positive Findings: Supine
Examiner’s standing with distal hand grasping the subject’s heel; proximal hand on subject’s knee with fingers palpating the medial and lateral joint lines
Action:
Knee fully flexed, externally rotate the tibia and introduce a valgus force and extend the knee
Medial Meniscus
Repeat with internal rotation of the tibia and Varus force.
Lateral Meniscus
Positive Findings:
“Clicking” indicates a Meniscal Tear
Medial side = medial meniscus
Lateral side = lateral meniscus

51. Unhappy Triad MCL, ACL, Medial Meniscus
Typically due to a valgus force with the foot planted
Shelbourne & Nitz 1991 studied 60 athletes with anteromedial knee injuries surgically
Found 58% Grade II MCL, 42% Grade III MCL, 11% of Grade II MCL Patients also had Medial Meniscus involvement while 71% of Grade II MCL patients also had LATERAL MENISCUS involvement, 17% of Grade II MCL patients also had osteochondral injuries
Most patients with medial meniscal injury also suffered lateral meniscal injuries as well
Grade III injuries were 60% LESS LIKELY to have meniscal injuries than Grade II injuries 51

52. PFJ Biomechanics During extension, patella glides cranially
During flexion, patella glides caudally
Patellar compression
OKC greatest at end range (final 30 degrees)
increases in CKC after 30 degrees of flexion

53. Patellofemoral Pain Syndrome
General term to describe anterior knee pain
Caused by a variety of factors:
Signs & Symptoms:
Poorly localized Pain
Little to no swelling
Pt. Tenderness under lateral patella
Insidious onset

54. Clark’s Sign (Patellar Grind Test)
Position:
Patient is lying supine w/ knee extended
Examiner places the web space of the thumb on the superior border of the patella
Action:
Subject contracts the Quads while the examiner applies downward and inferior pressure to the patella
Positive Finding:
Pain with movement of patella or inability to complete test
Chondromalacia patella or patellar femoral syndrome

55. Patellar Apprehensive Test
Position:
Patient is supine and relaxed
Action:
Examiner grabs patella and pushes it in all 4 ways
Superior / Inferior
Lateral / Medial
Positive Findings:
Patient Apprehension
Excessive Movement in one direction
Dislocating Patella

56. Osgood-Schlatter’s Disease

57. Housemaid’s knee