Small Animal Ortho: MPL & LPL Flashcards
What are the risk factors for patella luxation?
Small toy breeds
Usually bilateral
Which type of patella luxation is the most common?
Medial patella luxation
What type of luxation is seen in traumatic injuries and who does it effect more?
Lateral patella luxation & it is seen in large breeds more commonly
Usually unilateral
Where is the patella supposed to sit normally?
Trochlear groove of the tibia
What is the pathogenesis of luxating patellas?
may result from abnormal hip conformation.
displacement of the quadriceps mechanism leads to patellar luxation
Which angle is most commonly seen with a medial patella luxation?
Coxa vara: where the femur angles more medially
Which angle is most commonly seen with lateral patella luxations if it is congenital?
Coxa valga: where the femur angles more laterally
What are the secondary changes seen in the limb?
medial displacement of the quadriceps
lateral bowing of the femur
torsion of distal femur
shallow trochlear groove
stifle instability
medial displacement of tibial tuberosity
What are the common clinical signs of patella luxation?
intermittent lameness “hopping”
crouched stance “bowlegged”
lameness may increase as DJD develops
How are luxating patellas typically diagnosed?
Clinical sings
PE
Radiographs
What are the characteristics of grade 1 patella luxation?
Can’t usually push the patella out unless they are under general anesthesia
rarely lame, occ. skip
What are the characteristics of grade 2 patella luxation?
Patella will move out on its own but will pop back in
lameness varies- occ. skip to weight bearing lameness
What are the characteristics of grade 3 patella luxation?
Patella likes to stay luxated but we can move it back into place
chronic lameness of varying severity
What are the characteristics of grade 4 patella luxation?
Patella is out all the time & we cannot move it back into place
limb is carried or the animal moves in a crouched stance
What is the prognosis for surgical repair of patella luxations?
The lower the grade the better the prognosis
reluxation is common
does not prevent OA
improves function in dogs w/ lameness
