stifle joint, cuciate ligament rupture Flashcards
cruciate ligament rupture
- how common?
- large vs small breed ages
- assoc
- risk factors
- cats?
- MOST frequent cause of lameness in stifle
- Large breed dogs
> CrCL rupture < 4 years - Small breed dogs
> Usually > 7 years
> Sometimes associated with patellar luxation - Neutered > intact
- Overweight?
- Cats are also affected but less frequent
CL rupture pathophysiology
- etiology, progression and presentation
- Unknown, multifactorial
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Degenerative - Bilateral
- Degeneration is observed in ligaments of older/heavier dogs
- Repetitive strain injury?
- Genetics
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Trauma: RARE! - <>humans
- Young dogs <1Year
CL rupture history
Chronic progressive weight-bearing lameness with an acute episode of non-weight-bearing lameness
* Degeneration of ligament
* Rupture with or without meniscal injury
* Often associated with MINOR trauma
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* Large, middle-aged dog
* Acute onset of lameness without any history of previous lameness uncommon
Roles of the Cruciate Ligament
- Prevent cranial displacement of tibia
- Prevents hyperextension
- Limits internal rotation
CL rupture Musculoskeletal examination findings
- Pelvic limb lameness
- Stifle effusion
- Positive drawer or Tibial Compression Test
- Pain on hyper-extension (Good for partial tear)
- Sits with stifle extended on the affected side
- Medial buttress
- ± Meniscal click
Meniscal injuries
- how commonly related to cruciate problems
- anatomic location affected? why?
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- how can we tell? signs
- Up to 80% of chronic cruciate develop meniscal injuries
- Affects CAUDAL HORN of MEDIAL meniscus
> Because of attachment to tibia only
> Crushed when tibia displaces
<><> - Sometimes audible “click” when walking
> Less than 10% of meniscal injuries have an audible “click” - Increased pain and lameness
Meniscal Injury Treatment
- damage vs intact Tx
- Controversial!
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If damaged: must be removed (more OA) - Partial meniscectomy
- Remove caudal horn
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If intact - Leave: 10% chance of late injury
- Meniscal release?
Conservative Treatment for meniscal / stifle issue?
- when is it ok?
- what do we do?
- success rate?
With rest, the joint MAY fibrose and partially stabilize
* Generally considered OK for cats
* Acceptable for Small breed dogs (<15kg)
* Not indicated for medium or large breed dogs
* Not indicated if meniscal injury
> Exercise restriction (2-3 months) to allow stifle stabilization
> Weight loss if applicable
> ± NSAIDs
> Chondroprotective agents
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Successful in most cats
Successful in 70% of small breed dogs
Successful in <20-40% of large breed dogs
Orthoses use for stifle issues
- Little evidence of efficacy
> No proper long term study
<><> - Must be properly made
- Must be properly fitted
- Cost ($1000-1500)
- Compliance!
- Relies on fibrosis of joint
<><> - Not an ideal solution
surgical techniques that provide temporary/Semi permanent stabilization of the stifle
Extracapsular techniques
* Lateral fabellotibial suture
* “Tightrope” technique
*…
surgical techniques that permanently change the mechanic of the stifle
Osteotomy techniques
* Tibial plateau leveling osteotomy (TPLO)
* Tibial tuberosity advancement (TTA)
*…
Extracapsular techniques
* Lateral Fabellar-Tibial suture
* “Tight Rope”
> what are these, and what do they do? how do they compare? what do they rely on?
- Lateral Fabellar-Tibial suture
> Heavy suture through hole in the tibial tuberosity and around lateral fabella (generally Nylon) - “Tight Rope”®
> Heavy Polyester suture through holes in tibia and femur secured with metallic buttons or bone anchors
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Provide Temporary stabilization - Tight Rope more durable
- Ultimately rely on fibrosis of joint
Tibial Plateau Leveling Osteotomy
- what is our goal / strategy?
- result?
- Normal plateau angle
> 24 +/-3 degrees - Slope creates “tibial thrust” when weight bearing
- Cranial tibial thrust is opposed by intact CrCL
- When ruptured, tibial thrust is un-opposed
- Decreasing the TPA will reduce tibial thrust
<><><> - Tibial plateau rotated until perpendicular to functional tibial axis
- TPLO eliminates cranial tibial thrust
- TPLO does not eliminate drawer sign
- Stifle joint becomes functionally stable under loading
Tibial Tuberosity Advancement
- what is the goal / strategy?
Tibial tuberosity advancement
* Re-orient the patellar tendon to be perpendicular to the tibial plateau
* Eliminate tibial thrust during contraction of the quadriceps (pulls the tibia back)
stifle surgeries post operative management?
- Strict rest 6 weeks
- Exercise restriction for 8-12 weeks until
>Healed (TPLO, TTA)
> Fibrosed (Extracapsulars or conservative)
<><><><> - Antibiotics for TPLO (Higher rate of infection)
- NSAIDs, analgesics
- Physiotherapy +/- Chondroprotective agents
