Lecture 8 2/4/25 Flashcards
What are the differentials for disorders of the stifle?
-cranial cruciate ligament rupture
-medial meniscus injury
-caudal cruciate ligament rupture
-collateral ligament damage
-deranged stifle joint
-patella luxation
-OCD of the lateral femoral condyle
-trauma/fractures
What is the signalment for cranial cruciate ligament rupture?
-any breed
-common in labrador, rottweiler, bassett, and daschund
-dogs over 22 kg in weight; obesity plays a role
-females > males
-neutered > intact
What are the potential components of a cranial cruciate ligament rupture?
-complete tear/avulsion
-partial tear
-meniscal damage
-contralateral tear
What are the characteristics of CCL rupture prognosis?
-leads to progression of OA
-surgical treatments are associated with improved function and stabilization of the stifle
-no treatment has been proven to be effective in preventing OA development following rupture
Why should librela not be used in CCL rupture patients?
the innervation is needed so the dog continues to protect the damaged joint
What is the clinical presentation of CCL rupture?
-usually insidious in onset
-lameness
-pain on passive motion of stifle
-joint effusion
-thickened joint
-cranial drawer instability
-meniscal click
What are the potential pathophysiologies of cranial cruciate lig. rupture?
-trauma
-structural deformity
-pre-existing degeneration
What is the most common cause of CCL rupture in dogs?
slow, gradual degradation followed by complete rupture; sometimes involves relatively mild forces on the stifle
Which radiographic views are used to assess the stifle in a suspected CCL rupture?
-lateral
-VD
What is the use of radiographs when assessing a patient for CCL rupture?
-evaluate for secondary OA
-evaulate tibial plateau angle
What is the pathogenesis of medial meniscal injury in CCL rupture?
firm attachment of medial meniscus to tibia renders it susceptible to damage from cranial tibial subluxation along with greater weightbearing
Which injuries can occur to the medial meniscus in conjunction with CCL rupture?
-tears
-subluxation
What are the characteristics of surgical management of CCL rupture?
-nearly all dogs with CCL rupture should have a stabilization procedure
-exceptions are dogs that cannot tolerate GA, dogs with terminal disease, and dogs with no lameness or joint effusion
What are the characteristics of the modified retinacular imbrication technique?
-heavy monofilament nonabsorbable material is used for fabellar-tibial sutures
-scar tissue forms that increases joint stability
-size of suture should be appropriate for size of dog
-quick procedure with comparable results to other techniques
-post-op strength of repair is immediate and good
-risk to intra-articular structures is minimal
What are the characteristics of the tibial plateau leveling osteotomy technique?
-attempts to overcome the tendency for cranial tibial thrust during weight bearing
-changes the angle of the tibial plateau
-evidence of better outcome compared with other techniques
-rehabilitation must be delayed for 3 to 4 weeks while structures in stifle adjust to new joint angle
What are the characteristics of the CORA-based leveling osteotomy technique?
-new technique
-similar result as TPLO in terms of leveling the tibial plateau
-osteotomy is made more distal to the stifle joint than in the TPLO technique
What are the characteristics of the tibial tuberosity advancement technique?
-moves the tibial tuberosity so that pull from the quadriceps during weightbearing is perpendicular to the joint surface
-allows for compression at the joint rather than shear forces
-greater risk of meniscal damage/injury
-requires great infection prevention; implant is difficult to remove in the face of infection
What provides stability of the femoropatellar joint?
alignment of the quadriceps muscle and underlying bone
What can cause medial patella luxation?
-malalignment of the quadriceps complex
-malrotation of femur and tibia
-osseous deformity of femur and/or tibia
What is the progression of medial patella luxation?
-animal is born with a reduced patella/patella is in the correct place
-laxity of the femoropatellar joint worsens over time
What are the grades for medial patella luxation?
grade 1: intermittent luxation; goes right back
grade 2: intermittent luxation; easily moves in and out
grade 3: luxated, but can go in
grade 4: luxated, cannot reduce
What are the characteristics of medial and lateral patella luxation presentation?
-medial patella luxation is the most common presentation (70-80% of luxations)
-toy and miniature breeds are the most common breeds to experience MPL
-large and giant breeds make up the majority of LPL cases
-MPL is still the most common type of luxation in large and giant breeds
What are the clinical signs of medial patella luxation?
-little to no lameness with grade 1 luxation
-may walk with abnormal limb carriage
-intermittently carries limb, stretches it back, then is normal
-not wanting to jump
-potential for consistent lameness
-rapid progression of lameness with secondary cruciate ligament rupture
How is medial patella luxation diagnosed?
-history
-palpation of tibial tuberosity and patellar ligament
-palpation of trochlear groove relative to patella
-internally (externally) rotating tibia and applying lateral (medial) pressure on patella to luxate it while in different degrees of ROM (parentheses are for lateral luxation maneuver)
What are the surgical treatment options for patellar luxation?
-recession trochleoplasty if groove is shallow
-transplantation of tibial tuberosity
-capsulectomy
-desmotomy
-tenotomy
-suture restraint (puppies)
What are the types of recession trochleoplasty?
-V-wedge recession; triangular wedge of cartilage and bone is recessed
-block recession; rectangular wedge of cartilage and bone is recessed
What are the characteristics of tibial tuberosity transposition?
-changes the alignment of extensor mechanism relative to femoral trochlea
-used to correct both medial and lateral luxations
-tuberosity is moved laterally to correct medial luxations and medially to correct lateral luxations
What are the characteristics of a capsulectomy?
-arthrotomy is done on redundant side (side patella luxates away from)
-strip of joint capsule is removed
-suturing is done with opposing or overlapping pattern to close joint capsule
What are the characteristics of a desmotomy?
-releases excessive tension
-incision of shortened femoropatellar ligament
-no closure of the joint capsule
