Term
| What are the components of extensor mechanism of the stifle? |
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Definition
-quadriceps muscle group
-patella
-patellar tendon: inserts of the tibial tuberosity |
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Term
| What is the purpose fo the trochlear groove on the distal femur? |
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Definition
| -normal location for patella to sit |
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Term
| What is the purpose of the trochlear ridges on the distal femur? |
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Definition
| -help hold the patella in place |
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Term
| What is a patellar luxation? |
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Definition
| -occurs when the patella rides outside of the trochlear groove |
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Term
| What etiologies are behind patellar luxation? |
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Definition
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Term
| Describe the presentation of congenital patellar luxation. |
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Definition
-small/toy breeds most common
-present at young age
-50% bilateral
-MPL >>>>>> LPL (if LPL occurs it is in large breed dogs) |
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Term
| Is traumatic patellar luxation usually bilateral or unilateral? |
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Definition
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Term
| Describe the pathophysiology of medial patellar luxation? |
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Definition
-shallow/absent troclear groove
-malalignment of extensor mechanism
-abnormal hip joint conformation
-femoral malformation: angulation, rotational/torsional
-tibial malformation
-dviaiton of tibial crest
-quadriceps tightness |
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Term
| Describe a Grade I medial patellar luxation. |
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Definition
-patella can be luxated, but returns to its normal position spontaneously
-functionally normal |
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Term
| Describe a Grade II medial patellar luxation. |
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Definition
-patella luxates out of its groove occasionally
-can be replaced back into the groove with manipulation or reduces spontaneously |
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Term
| Describe a Grade III medial patellar luxation. |
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Definition
-patella luxates out of its groove most of the time
-CAN BE REPLACED BACK INTO THE GROOVE |
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Term
| Describe a Grade IV medial patellar luxation. |
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Definition
-patella luxates out of its groove all the time
-CANNOT BE REPLACED BACK INTO THE GROOVE |
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Term
| What clinical presentation do we see for congenital medial patellar luxation? |
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Definition
-skipping
-kicks leg straight backwards (trying to pop it back into place)
-lameness |
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Term
| What clinical presentation do we see with traumatic medial patellar luxation? |
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Definition
| -acute, non-weight bearing lameness |
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Term
| What do we do on physical exam with a medial patellar luxation? |
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Definition
-fully extend stifle joint
-internally rotate the tibia
-apply medially directed pressure to the patella as you begin to flex the stifle |
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Term
| Why would we evaluate a medial patellar luxation for CrCL ligament tear? |
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Definition
| -15-20% of patient with chronic MPL habe a CrCL tear |
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Term
| When would we choose surgery to treat a medial patellar luxation? |
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Definition
| -when the patient is clinically affected |
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Term
| What soft tissue procedures can we use to treat medial patellar luxation? |
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Definition
-medial retinacular release
-lateral retinacular imbrication |
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Term
| What are our surgical treatment options for medial patellar luxation? |
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Definition
-soft tissue procedures
-tibial crest transposition
-recession trochleoplasty
-corrective femoral/tibial osteotomies
-anti-rotational suture: lateral stabilization, patellofabellar suture |
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Term
| How do we treat a grade 4 medial patellar luxation? |
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Definition
-distal femoral osteotomy
-proximal tibial osteotomy |
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Term
| Describe the postop care for patellar luxation surgery. |
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Definition
-confinement for 8w
-modified robert jones for 2w
-pain control + OA
-recheck rads if TTT performed (K wire has to be removed) |
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Term
| What is the prognosis for patellar luxation surgery? |
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Definition
-Good (Grade 1-3) & poor/guarded (grade 4)
-OA will continue to progress AT SAME RATE
-up to 50% can reluxate postop |
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