Patella luxation Flashcards
Which luxation is the most common: medial or lateral?
- medial
What is the correct name for the femur bending that can give rise to patella luxation?
- femoral varus deformity
Cartilage loss occurs with this condition
From what surfaces is the cartilage lost?
If the cartilage loss exposes the underlying bone what is this process called?
- cartilage is lost from the medial femoral trochlear ridge and the articular surface of the patella
- eburnation
What breeds are predisposed to medial patellar luxation?
- toy breeds
- French bulldogs
- CKCS
- English bull terrier
- labs
Is lateral or medial more debilitating?
- lateral
What breeds are predisposed to lateral patellar luxation?
- Flat coated retriever
What breed is predisposed to simultaneous medial & lateral patella luxation?
- Springers
Why is straightening the femur as a tx for PL not recommended?
- risky
- complications
What CS indicates eburnation?
- crepitus
What 3 bones make up the knee?
- femur
- tibia
- patella
What bone does the patella tendon attach on?
- Tibia
What are the 2 forces that keep the patella tracking normally in the groove?
- deep walls
- straightness of muscle
What ligament secondary to patella luxation can become damaged?
- cranial cruciate ligament
What type of lameness is seen with patella luxation?
- skipping lameness
What large breeds are prone to medial patella luxation?
- English & Staffordshire bull terriers
- English bulldogs
- labs
- mastiffs
Grade 1 MPL
- patella luxation easily relocates into femoral trochlea
- usually not associated with CS
Grade 2 MPL
- luxates with ease
- external pressure is required to relocate the patella into groove
- this doesn’t happen spontaneously but extension of the stifle by the pt can bring this about
Grade 3 MPL
- patella lunated permanently
- requires considerable effort to replace into trochlear groove from which it immediately re-luxates
Grade 4 MPL
- permanently luxated
- can’t be replaced into the trochlea groove
% of MPL cases also suffering from concurrent cruciate dz?
- 42%
Benefit of prophylactic surgery on asymptomatic dogs with MPL
- no evidence for this
- prophylatic MPL surgery doest progress OA whether animal has surgery or not
Trade name for synthetic trochlea buttress?
- RidgeStop
Downside of trochleoplasties
- damage & destruction or hyaline cartilage
- exposed subchondral bone and initiates joint inflammation
What dog would you consider a distal femoral corrective ostectomy?
- advocated as component of MPL repair when osseous deformities include excessive femoral varus
- grade III & IV MPL in large breed dogs
