Lecture 10: Collateral & Multiple Lig Injury/Meniscal Injury (Exam 2) Flashcards
Define ligament injury
Complete or partial tear of the medial or lateral collateral lig
Describe a sprain
- A ligament injury
- 1st degree (mild) -> 2nd (mod) -> 3rd (complete tear)
Describe strain
- A muscle tendon unit injury
- No grading
- Resolve w/ rest
What is the function of the medial & later collateral lig
To limit varus-valgus motion of the stifle joint
What injuries occur w/ injuries to the medial or lateral collateral lig
Primary & secondary restraints of stifle
What causes multiple lig injuries
Severe trauma to stifle joint
How do you test the the collateral joints
Stifle needs to be in extension during PE
What test are used to test the integrity of the collateral ligs
- Valgus stress test for medial lig
- Varus stress test for lateral lig
Describe the valgus stress test
- Lateral recumbency
- One hand on femur
- Other hand on the distal tibia & applies upward force (abduction)
- Will see opening of the medial joint line if medial joint restraints are torn
Describe the varus stress test
- Px in lateral recumbency
- One hand stabilizes femur
- Other hand grasps distal tibia & applies inward force (adduction)
- If the lateral joint restraints are torn you will see opening of the lateral joint
Why are radiographs needed to dx
- Determine if the bone fragments associated w/ lig damage
- Craniocaudal & medial lateral radiographs indicated to confirm the presence or absence of bony avulsions
What does this radiograph show
- Medial joint opening
- Valgus stress applied on the joint
What should be in the differential Dx
- Muscle strain
- Cranial/caudal cruciate lig
- Non displaced physeal fractures in immature animal
What is used to determine if conservative or sx tx is needed
- Degree of injury
- Collateral lig itself
- Secondary joint restraints
When is medical management needed
- Min swelling & only slight opening of the joint space w/ stress test
- Indications for “conservative” tx
- 1st degree sprain (cast for ~ 2 W)
When is sx tx needed
- Mod to severe swelling & significant opening of the joint space w/ the stress test
- Indicates greater injury to collateral restraints
- 2nd & 3rd degree sprains
What is needs to be done in sx tx
Reconstruction of the collateral lig(s), meniscocapsular lig, & joint capsule
T/F: Repair all injured ligaments, tendons, & joint capsule
True
Which is the meniscofemoral lig
J
When is primary repair of the collateral ligs done
- If point of failure is origin or insertion of the ligament
- An intrasubstance tear w/ large segments of ligament intact
What should be done pre op
- Place a modified robert jones bandage
- Limit activity to leash walking
What are some periop abx & preemptive pain that can be given
- NSAIDs
- Opioids
- Epidural analgesia
Describe the medial collateral lig
- Origin: Medial femoral epicondyle
- Insert: Proximal tibial metaphysis
- Strong attachment to the joint capsule & medial meniscus
- Lied deep to the caudal sartorius m.
Describe the lateral collateral lig
- Origin: oval area on the lateral femoral epicondyle
- Insert: fibular head
- Lies deep to fascia lata
What should be preserved when dissecting near the lateral collateral lig
Peroneal (fibular) nerve
What is being done in this photo
What is being done in this photo
What should be done if the ligament injury is intrasubstance tear
- Primary repair by suturing ligament ends w/ locking loop suture pattern
- Supplement primary repair w/ screws & figure eight support
Label the following lig & tendon sutures
Describe the repair of a lateral restraint injury
- Craniolateral approach
- Make a proximal to distal parapatellar incision
- Cont incision distally (protect peroneal n.)
- Reflect fascial lata to expose the collateral lig & lateral joint capsule
- Repair lig as describe for MCL
What is the prognosis of tears
- Isolated collateral lig = good to excellent
- Multiple ligs = fair
What causes injuries where the cranial/caudal cruciate ligs & collateral ligs damaged simultaneously
Hit by a car or other major trauma
Describe the characteristics of multi lig injuries
- Mod to severe swelling & bruising of soft tissue surrounding the joint
- Torn collateral ligs are difficult to identify
- Menisci often displaced
What structures are commonly injured w/ multi lig derangement of the stifle
Loss of cranial & caudal cruciate ligs & disruption of the medial restraints
What is included in the common triad of injuries
- Cranial & caudal cruciate lig tears
- Failure of primary & secondary medial restraints
- Peripheral medial meniscal tears
What is the prognosis of multiple lig injuries
Fair
What are these pics showing
Deranged stifle
T/F: A meniscal release is controversial based on effects on the meniscus/cartilage & uncertain efficacy
True
What happens to the function of the meniscus when it is transected
Function is compromised by elimination of hoop stresses
What happens w/ midbody release or transection of the meniscotibial lig
- Femoral condyle increases contact w/ articular cartilage of the tibial plateau (contributes to osteoarthritis
- Impairs fxn of meniscus to provide stability to provide stability & congruence
Are there clinical studies demonstrate efficacy of meniscal release in decreasing incidence of post TPLO meniscal injury
No
Describe medical management of meniscal injuries
- Conservative tx is not an option
- Accelerates DJD
What is the easiest approach to perform a medial meniscectomy
Medial surgical approach
Describe removal of just the torn section of the meniscus (partial meniscectomy)
- Experimentally: partial meniscectomy carries less morbidity than a total
- Tx of choice for bucket handle tears of medial meniscus
In dogs why is the primary repair reserved for peripheral tears
- Uncommon
- Difficulty in suturing meniscal body tears in dogs
- Low morbidity associated w/ partial meniscectomy
What induces severe DJD in stifle
Total meniscal removal
The more meniscal tissue removed the more what
The more rapidly OA dev
