Ligament Injury Flashcards
What are the 3 articulations of the stifle joint?
- femorotibial - main, primary weight bearing
- femoropatellar - improves efficiency of extension by increasing the movement orm of the quadriceps
- tibiofibular - secondary support
What are the 4 sesamoid bones of the stifle?
- patella - blunt proximally, pointed distally (apex)
- lateral fabella - larger, spherical
- medial fabella - smaller, angular
- popliteal - in the popliteal tendon of the lateral condyle of the tibia
What is the purpose of sesamoid bones?
relieve tension within muscles and tendons, allowing for increased weight bearing and tolerance by redistributing forces throughout a muscle or tendon —> protection from strain and injury
Femorotibial joint:
Where do the cranial and caudal cruciate ligaments originate and insert?
CRANIAL = originates from the caudomedial aspect of the lateral femoral condyle, inserts on the medial tibial plateau
CAUDAL = originates from the craniomedial aspect of the medial femoral condyle, inserts on the posterior tibial plateau
Menisci:
medial most commonly tears
What is the function of the cranial cruciate ligament? In what 3 ways does it do that?
stability of the stifle joint
- limits cranial translation of the tibia
- limits internal rotation of the tibia
- limits hyperextension of the stifle
What are the stifle menisci made of? What is their purpose? What is their blood supply like?
C-shaped fibrocartilage primarily made up of Type 1 collagen in a matrix
resists hoop stress
poor —> thick periphery is vascularized by plexi in the joint capsule
What is the purpose of a meniscal release? How. isit performed?
treats impingement by allowing the caudal horn of the meniscus to move more freely with movement of the joint in the presence of cranial tibial thrust
mid-body meniscal transection +/- transection of the caudal tibial ligament
Are complete meniscectomies performed?
NO —> causes the development of advances arthritis because there is no longer any cushion
- it used to be thought that the menisci do not do much
What is the most common etiology of cranial cruciate ligament tears in dogs?
degenerative
(trauma in humans)
What are the 5 major causes of the degeneration that leads to cruciate ligament tears?
- conformational abnormalities - proximal tibia, straight legs
- hormonal - early castration
- autoimmune
- age
- body weight
(idiopathic possible)
How is cranial cruciate ligament tears diagnosed?
- ORTHOPEDIC EXAM - gait analysis, compensatory thickening, cranial drawer, tibial compression
- RADIOGRAPHS - can’t see ligaments, secondary changes
What cats are likely to tear their cranial cruciate ligaments?
old, obese
How is the gait changes by cranial cruciate tears? What is the sit test?
shifting, off-loading
it hurts to flex legs, so dogs with a torn CrCL will keep their legs extended