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The Knee Complex
Dr. McGowan's Lecture on knee anatomy and biomechanics
43
Anatomy
Graduate
11/07/2010

Additional Anatomy Flashcards

 


 

Cards

Term

 

 

Joints of the Knee

Definition
  1. Tibiofemoral
  2. Patellofemoral
  3. Proximal Tibiofibular

*Not too concerned with distal tibiofibular for this test

Term

 

 

How many degrees of freedome are at the knee?

Definition

 

 

6

Term

 

 

Physiologic motions at the knee

Definition

 

 

Flex, Ext, Rotation

Term

 

Knee Loose Packed Position

Definition

 

 

25 degrees flexion

Term

 

 

Knee closed packed position

Definition

 

 

full extension with external rotation of tibia

Term

 

 

Knee capsular pattern

Definition

 

 

Flexion > Extension

Term

 

 

Medial Meniscus

 

 

Definition

 

 

Larger and thicker than lateral meniscus

 

thicker and wider posteriorly

 

less mobile

Term

 

 

Lateral meniscus

Definition

 

smaller and thinner than medial meniscus

 

More mobile than medial meniscus

Term

 

 

When is MCL taut?

Definition

 

 

Full Extension

Term

 

 

What does the MCL resist?

Definition

 

 

Primary restraint to excessive abduction/valgus and lateral rotation

 

*greatest at 25-30 degrees flex

Term

 

 

LCL

Loose Packed?

Close Packed?

Definition

 

 

Loose--Flexion

Closed--Extension

Term

 

 

What ligament provides primary restraint

to anterior translation of tibia on femur and lateral rotation of tibia in flexion?

Definition

 

 

 

ACL

Term

 

 

What percentage of forces causing anterior

translation does the ACL absorb?

Definition

 

 

90%

Term

 

 

Common Mechanisms of injury to ACL

Definition

 

  • Foot planted and femur vigorously externally rotated (often in conjunction w/ valgus force)
  • Hyperextension w/ foot planted
Term

 

 

Which is thicker PCL or ACL?

Definition

 

 

PCL is 50% thicker and has twice the

tensile strength of the ACL

Term

 

 

Medical Term for Bow-Legged

Definition

 

 

Genu Varum

Term

 

 

Genu Varum

Definition

 

 

increased compression forces medial knee and distraction lateral knee

Term

 

 

Medical term for Knock-Kneed

Definition

 

 

Genu Valgum

Term

 

 

Genu Valgum

Definition

 

 

Increased compression forces lateral knee and distraction medial knee

Term

 

Female Tibiofemoral Alignment

Definition
  • Wider Pelvis
  • Femoral Anteversion
  • Genu Valgum
  • Increased Flexibility
  • Lateral Tibial Torsion
  • Narrow Patella Notch
Term

 

 

Male Tibiofemoral Alignment

Definition
  • Narrower Pelvis
  • Larger Muscle Mass
  • Genu Varum
  • Medial Tibial Torsion
  • Wider Patellar Notch
Term

 

Patellofemoral Joint

Loose Packed?

Definition

 

 

Full extension

Term

 

Patellofemoral Joint

Closed Packed?

Definition

 

 

90 degrees flexion

Term

 

Patellar Motion/Tracking

120-30 flexion?

Definition

 

  • Patella is drawn medially into femoral trochlea
  • Medial glide and medial tilt of patella
Term

 

 

Patellar Motion/Tracking

 

30-0 flexion?

Definition

 

 

  • Lateral glide and lateral tilt of patella
Term

 

 

Patellar Area of Contact

 

Hint: Picture/Diagram

Definition
[image]
Term

 

 

Restraints to Lateral Glide of Patella

Definition
  • Medial patellofemoral ligament (60%)
  • Lateral Femoral Condyle
  • Medial Retinaculum
  • Medial VMO
Term

 

 

Factors that effect patellar alignment

Definition
  • Tight lateral structures (TIB, lat. retinaculum)
  • Tight gastroc and hamstrings
  • Patella alta
  • Excessive ankle pronation
  • Femoral anteversion (medial femoral torsion)
  • VMO insufficiency or VM/VL imbalance
  • Increased quad angle (Q-angle)
Term

 

 

Insall-Salvati Index

Definition
  • Optimally 1:1 ratio of length of patellar tendon to length of patella
  • Patella alta and baja when correct ratio not present
Term

 

 

 

Patella Alta

Definition

 

 

Lengthened Patellar Tendon

Term

 

 

 

Patella Baja

Definition

 

 

Shortened Patellar Tendon

Term

 

 

Camel Sign

Definition

 

 

Patella Alta

 

May present w/ second hump = infrapetellar fat pad/bursa

Term

 

 

Arthrokinematics of closed chain extension

Definition

 

 

femur rolls anteriorly on tibia then glides posteriorly

Term

 

 

 

Medial rotation of the femur occurs during

 

Extension OR Flexion?

Definition

 

 

Extension

 

*during last 30 degrees movement halts on lateral compartment but continues on longer medial compartment

Term

 

 

Screw Home Mechanism

Definition

 

 

  • 5-0 degrees WB knee ext
  • rotation is ONLY movement accompanying extension
  • tibia externally rotates and femur internally rotates
Term

 

Arthrokinematics

 

Closed chain flexion

Definition

 

  • Popliteus unlocks joint
  • Tibia internally rotates under femur
  •  femur rolls post and tibia glides ant
  • ACL check any post roll and ant glide of femur

 

Term

 

 

Arthrokinematics

 

Open Chain Flexion

Definition

 

  • Tibia rolls and glides post on femur
  • External rotation tibia under femur
Term

 

Arthrokinematics

 

Open Chain Extension

Definition

 

  • Tibia rolls and glides anteriorly on femur
  • Internal rotation of tibia under femur
Term

 

 

Is meniscal distortion inevitable?

Definition

 

YES!!

 

*inner sides of menisci are attached by horns to tibial plateau and move with tibia

BUT

 

*durin motion, menisci move on tibia with femoral condyles to maintain joint congruence

Term

 

 

Result of menisci receiving slip of quad tendon?

Definition

 

 

Anterior translation of menisci during extension

Term

 

 

Medial Meniscus motion during flexion

Definition

 

 

pulled ~2-5 mm by semimembranosus tendon

Term

 

 

Lateral Meniscus motion during flexion

Definition

 

 

pulled 10-11 mm by popliteus

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