Q4: Knee Orthoses

Question 1

Primary Uses

KOs

Answer 1

• Coronal Issues
• Arthritis
• Hyperextension

Suspension is a primary issue

Question 2

Tibial Plateau

Functional Anatomy of the Knee

Answer 2

Lateral aspect is smaller and convex
Medial aspect is larger and concave

Question 3

Menisci

Functional Anatomy of the Knee

Answer 3

Create an increase in congruence between tibia and femur

Question 4

Menisci

Relevant Characteristics

Answer 4

• Viscoelastic - shock attenuation
• Made of fibrocartilage
• Richly innervated
• Center is avascular

Question 5

Femoral Condyles

Functional Anatomy of the Knee

Answer 5

Asymmetrical
* Lateral - wider but shorter
* Medial - thinner but longer

Lateral/Medial divided by femoral trochlea

Question 6

ACL/PCL

Functional Anatomy of the Knee

Answer 6

rise from the intercondylar notch

Question 7

Facets of the Femur

Functional Anatomy of the Knee

Answer 7

• Lateral - Concave and largest
• Medial - Convex
• Odd - only articulates at the end range of knee flexion

Question 8

Patellofemoral Joint Syndrome

Functional Anatomy of the Knee

Answer 8

• pain is common in the athletic population
• females more likely to develop
• Managed conservatively (unless no improvement after 6 months - then Sx)

Question 9

ACL

Primary Roles of Ligaments

Answer 9

Resist anterior displacement of tibia relative to femur

Secondary - resist varus when extended

Question 10

PCL

Primary Roles of Ligaments

Answer 10

Resist posterior displacement of the tibia relative to the femur

Secondary - Resists varus when extended

Question 11

LCL

Primary Roles of Ligaments

Answer 11

Resists varus when knee is 30 degrees flexed

Secondary - resists ext. rotation below 50 degrees of flexion

Question 12

MCL

Primary Roles of Ligaments

Answer 12

Resists valgus angulation

Secondary - Limits rotation with help of ACL

Question 13

MCL vs. LCL

Biomechanics of the Knee

Answer 13

• MCL has more stretch than the LCL
• MCL attaches to med/meniscus (LCL does not)

Question 14

Stability of the Knee

Biomechanics of the Knee

Answer 14

13 muscles assist to knee stabilization

Meniscis also assist by increasing SA; minimal perfusion

Question 15

Axis of Rotation

Knee Joint

Answer 15

Polycentric in nature
* Follows a J-shaped path
* Tibia rolls and glides on femur
* Flexion initiated by int. rotation of tibia

Question 16

Screw Home Mechanism

Answer 16

Locking - medial tibial condyle moves anterior (ER)
Unlocking - medial tibial condyle moves posteriorly (IR)

Question 17

Patellofemoral Syndrome

Conservative Management

Answer 17

• PT - strengthening
• Ox - FOs; 1 study shows Bauerfiend Genutrain (KO sleeve) helps
• Taping - not as much evidence

Question 18

Prophylactic KOs

Ox Design

Answer 18

Prevent Injury
* inhibit coronal motion
* can have one or two sidebars (single axis)

Question 19

Post-Op KOs

Ox Design

Answer 19

Treat acute injury
* prevent excessive loads on impaired ligament
* allow early return to activity
* longer lever arms

Question 20

Functional KOs

Ox Design

Answer 20

Return to ADLs/Athletics
* bilateral sidebars
* polycentric joints
* inhibit ant. migration of tibia on femur (protect ACL)

Question 21

Limitations of KOs

Ox Design

Answer 21

• Migration distally - suspension issues
• Shorter lever arms than KAFOs
• Only crosses the knee (no transverse motion control)

Injuries to other athletes can occur too

Question 22

“Unhappy Triad”

Knee Injuries

Answer 22

ACL, MCL, and medial Meniscus

Sx is almost always indicated

AKA: O’Donoghue’s Triad

Question 23

ACL

Knee Injuries

Answer 23

Noncontact (70%)
Contact (30%)

50/50 if Sx is needed

ACL comprised of
fibrocartilage; inability to heal

Question 24

PCL

Knee Injuries

Answer 24

MOI - forced HE from direct blow

50% of time correlated with other ligament injuries

Question 25

MCL | Knee Injuries

Answer 25

MOI - Valgus stress on flexed knee Commonly injured with other ligaments (ACL usually) | Most common ligament injury in knee

Question 26

LCL | Knee Injuries

Answer 26

MOI - direct blow resulting in excessive varus | Isolated cases are very rare

Question 27

MCL Injury Treatment | Grade I/II Sprains

Answer 27

Compressive knee sleeve OR adjustable ROM KO

Question 28

PCL Injury Treatment | Grade I/II Sprains

Answer 28

Weight bearing as tolerated; KO set in terminal extension

Question 29

LCL Injury Treatment | Grade I/II Sprains

Answer 29

KO locked in terminal extension

Question 30

ACL Injury Treatment | Grade I/II Sprains

Answer 30

Adjustable ROM KO

Question 31

ACL Injury Treatment | Grade III Sprains

Answer 31

Reconstruction for more active individuals | Less active peoples can return to preinjury levels with PT and Ox

Question 32

Adjunct Therapies | Grade I/II Sprains

Answer 32

* PT - return to activies when 80% strength and ROM returns * NSAIDs

Question 33

PCL Injury Treatment | Grade III Sprains

Answer 33

Conservative Management; Sx only if CM does not work | Fibroblast allow for potential healing; Ox for 2-4 weeks

Question 34

MCL Injury Treatment | Grade III Sprains

Answer 34

Conservative Management for isolated injuries | KO set in 30 degrees of flexion with PT

Question 35

MCL Injury Treatment | Grade III Sprains

Answer 35

Conservative Management for isolated injuries | KO set in 30 degrees of flexion with PT

Question 36

LCL Injury Treatment | Grade III Sprains

Answer 36

Reconstruction typically indicated

Question 37

Efficacy of KOs

Answer 37

* Prophylactic - favorable outcome but increased fatigue * Rehabilitative - Ox are a primary reason for reduced Sx management * Functional - without a brace, Sx outcomes not favorable

Question 38

"Does bracing patients that underwent ligament reconstruction decrease the likelihood of future re- injury?"

Answer 38

Some of the strong studies say “NO”

Question 39

Medial Compartment OA

Answer 39

Most common location in knee Occurs with varus when medial compartment bears more than 70% of axial load

Question 40

Lateral Compartment OA

Answer 40

Occurs with valgus when lateral compartment bears close to 50% of axial load | More common for individuals with RA

Question 41

Knee Adduction Moment

Answer 41

GRF passes medial to the knee center creating sudden adduction; OA of medial compartment often seen

Question 42

OA - Coronal Plane Alignment | KO Design

Answer 42

LoadShifter Mechanism * The patented LoadShifter technology allows tool-less adjustability via the innovative SnapLock allowing the practitioner to easily accommodate the patient's anatomy or the degree of unloading quickly and easily.