Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
|
Why is a metal-backed tibial component used? What is the clinical significance?
|
Decreases compressive force on tibial plateau
Minimizes osteolysis |
|
|
What are the reported outcomes for tibial component with cement only under the metaphysis and a press fit stem?
|
Increased risk of loosening relative to cementing entire component
|
|
|
Is a metal-backed patellar component routinely used?
|
No, as it has increased wear
All polyethylene patellar components are routinely used |
|
|
What is the theoretical advantage of cruciate retaining total knee arthroplasty?
|
Allows for physiologic rollback of femur on tibia
|
|
|
Has this been borne out in radiographic studies?
|
Fluoroscopic studies have found cruciate retaining knees do not exhibit physiologic rollback
|
|
|
The most normal knee kinematics are actually seen with what knee design?
|
Unicompartmental total knee arthroplasty
|
|
|
What are the three symptoms of late cruciate failure after cruciate-retaining TKA?
|
Effusion
Flexion instability Pain |
|
|
In what four situations is a posterior stabilized knee indicated instead of cruciate retaining?
|
Patellectomy
Inflammatory arthritis PCL absent or over-released Prior HTO |
|
|
What are the two theoretical advantages of a PS knee?
|
Improved flexion
Mechanical rollback achieved |
|
|
Use of a PS knee requires careful attention to what to prevent what complications?
|
Well-balanced knee required to prevent dislocation
|
|
|
Hyperflexion of a PS knee may lead to what complications?
|
Dislocation
|
|
|
What are the two caused of cam impingement?
|
Hyperextension
Femoral component flexion |
|
|
Moving the joint line in what direction increases the chance of impingement?
|
Joint line elevation may lead to patella baja and increased chance of impingement
|
|
|
A patellar clunk is classically associated with PS knee in what position? What generally causes it?
|
Extension
A superior nodule |
|
|
How does mobile bearing articular conformity compare with standard TKA?
|
Improved
|
|
|
How do mobile bearing interface stresses compare with those in a standard knee?
|
Decreased
|
|
|
Have improved clinical outcomes been demonstrated with mobile bearing knees?
|
No
|
|
|
What two factors increase the risk of mobile bearing knee dislocation?
|
Valgus alignment
Older patient |
|
|
What are the four preoperative criteria for unicompartmental knee arthroplasty?
|
Correctable valgus/varus deformity (not fixed deformity)
Flexion >90 degrees <10-degree flexion contracture No inflammatory arthritis |
|
|
With medial unicompartmental replacement, what is the desired postoperative alignment?
|
0 to 3 degrees valgus
|
|
|
What is the reported advantage of a minimally invasive unicompartmental knee replacement?
|
Faster rehabilitation
|
|
|
How do failures from fixed bearing unicompartmental knees typically present?
|
Component failure
|
|
|
What is the presentation of failure after mobile bearing unicompartmental knee?
|
Disease progression
|
|
|
In general, in what situation should bilateral total knees be staged?
|
If patient has many medical comorbidities
|
|
|
What is the most common complication of simultaneous bilateral total knee arthroplasty?
|
Deep venous thrombosis (DVT)
|
|
|
What is the short-term benefit to a subvastus approach? Is there a long-term benefit?
|
Improved early range of motion (ROM)
No long-term benefit |
|
|
What is the observed clinical effect of patella baja in total knee arthroplasty?
|
Decreased flexion
|
|
|
In general, what are the four treatment options for patella baja?
|
Lower the joint line
Use small superior paterllar dome Cut patellar polyethylene at impingement points Do not resurface the patella |
|
|
In general, what are the outcomes of TKA in the setting of arthrofibrosis?
|
Unpredictable
|
