Lecture 10: Collateral & Multiple Ligament Injury/Meniscal Injury

collateral ligament injury

complete or partial tear of medial or lateral collateral ligament

ligament injury =>

sprain!

1st, 2nd, 3rd degree sprains

1st = mild

2nd = moderate

3rd = complete

muscle tendon unit =>

strain!

no grading

most resolve with conservative management with rest

general considerations

medial and lateral collateral ligament function

limit varus-valgus motion of stifle joint

isolated medial or lateral collateral ligament tears rare in small animal

medial view anatomy

injuries to medial or lateral collateral ligaments:

occur with injury to other primary and secondary restraints of stifle joint

multiple ligament injuries result from:

severe trauma to stifle joint

involve injury to other stifle joint ligaments

lateral view anatomy

signalment

dog or cat

any age or breed

either breed

hx of collateral and multiple ligament injury

may occur while exercising - w/o evidence of trauma

traumatic incident (vehicular accident) where animal has sustained major injuries

PE with collateral and multiple ligament injury

dx of collateral ligament injury

• based on palpation

stifle joint extended to examine for collateral injury

cranial view anatomy

the valgus stress test evaluates the

medial collateral ligament

the varus stress test evaluates the

lateral collateral ligament

to examine the collateral ligaments:

apply medial and lateral pressure to tibia

• assess integrity of collateral ligaments

how to perform the valgus stress test:

P in lateral recumbency

one hand stabilizes femur-other hand grasps distal tibia and applies upward force (abduction)

if medial joint restraints torn

• see opening of medial joint line

• medial collateral ligament (MCL), joint capsule, peripheral meniscal ligaments

how to perform the varus stress test

P in lateral recumbency

one hand stabilizes femur-other hand grasps distal tibia and applies inward force (adduction)

if lateral joint restraints are torn

• see opening of lateral joint

• lateral collateral ligament (LCL), joint capsule, peripheral meniscal ligaments

MCL tear

isolated tears show minimal opening

obvious opening occurs with more extensive injuries

radiographs for collateral and multiple ligament injuries

determines if bone fragments associated with ligament damage

craniocaudal and medial-lateral radiographs indicated: confirm presence or absence of bony avulsion

stress radiographs: show increase in medial or lateral joint space

note severity of joint opening

• valgus stress applied to joint

stress radiograph of cat w/ MCL injury

laboratory findings:

consistent lab findings not seen

lab evaluation depends on signalment and physical findings in animals w/ trauma

diff. diagnosis

muscle strains

cranial or caudal cruciate ligament tears

nondisplaced physeal fractures in immature animals

medical management

conservative or surgical treatment for isolated collateral ligament injury based on degree of injury

• collateral ligament itself

• secondary joint restraints (joint capsule, peripheral meniscal ligaments)

assessment based on palpation and radiographs

criteria for medical management:

minimal swelling and only slight opening of joint space with stress test

• indications for conservative treatment

• 1st degree sprain

  • fiberglass cast applied for 2 weeks

  • followed by controlled activity for 6 additional weeks

surgical treatment criteria:

moderate to severe swelling and significant opening of joint space with stress test

• indicates greater injury to collateral restraints

• 2nd and 3rd degree sprains

treatment includes reconstruction:

• collateral ligament(s)

• meniscocapsular ligaments

• joint capsule

be sure to repair all injured ligaments, tendons, and joint capsule

LITERALLY DON’T FORGET THIS BEAUTIFUL PEOPLE

primary repair of collateral ligaments done if:

point of failure is origin or insertion of ligament

an intrasubstance tear with large segments of ligament intact

occasionally small fragment of bone present on ligament

• can be incorporated into repair

preoperative management

to prevent additional damage to articular cartilage or menisci:

• place modified Robert Jones bandage on limb

• Limit activity to leash walking

=> until surgery

animal evaluated for evidence of trauma to other ligaments or bones

preoperative management, P criteria:

Patients w/ injuries by HBC

• thoracic, cardiovascular, and abdominal evaluation

perioperative antibiotics and and preemptive pain management

• NSAIDS

• Opioids

• epidural analgesia

=> indicated for animals undergoing stifle reconstruction

surgical anatomy

medial collateral ligament

knowledge of origin and insertion points of collateral ligament is important

medial collateral ligament

• originates from medial femoral epicondyle

• runs distally to insert onto proximal tibial metaphysis

• as ligament crosses medial joint line

  • strong attachment to joint capsule and medial meniscus

• lies deep to caudal sartorius muscle

lateral collateral ligament

surgical anatomy

• originates from oval area on lateral femoral epicondyle

• runs distally to insert onto fibular head

• lies deep to fascia late

careful when dissecting near lateral collateral ligament!

• preserve peroneal (fibular) nerve!!!

peroneal (fibular) nerve

surgical anatomy

• branch of sciatic nerve

• obliquely crosses distal aspect of stifle joint

• superficial to gastrocnemius muscle

• sends articular branch to lateral collateral ligament

patient positioning for lateral collateral ligament injury

position patient in lateral recombancy with affected leg up

patient positioning for medial collateral ligament injuries

position animal in dorsal recumbency

patient positioning for multiple ligament tears

• dorsal recumbency to facilitate exposure of both sides of limb

• suspend limb and prepare for aseptic surgery

repair of a medial restraint injury

step 1:

incise insertion caudal head of sartorius muscle and deep fascia along craniomedial border of proximal tibia

repair of a medial restraint injury

step 2:

replace collateral ligament to its anatomic site and secure with screw and spiked washer

repair of medial restraint injury

step 3:

if ligament injury is intrasubstance tear:

• primary repair by suturing ligament ends with locking-loop suture pattern

• supplement primary repair with screws and figure-eight support

ligament and tendon sutures

repair of a lateral restraint injury

• craniolateral approach to expose lateral collateral ligament

• make proximal-to-distal parapatellar incision through fascia lata

• continue incision distally 4 cm below tibial crest parallel to joint line

  • use caution isolate and protect peroneal nerve

• reflect fascia lata caudally

  • expose collateral ligament and lateral joint capsule

• repair ligament as described for MCL

Prognosis of isolated collateral ligament tears is:

good to excellent

prognosis if multiple ligaments are torn prognosis is:

fair

multiple ligament injuries are:

injuries where cranial or caudal cruciate ligaments and collateral ligaments damaged simultaneously

• caused by HBC or other major trauma

surgical anatomy for multiple ligament injuries

• moderate to severe swelling and bruising of soft tissue surrounding joint seen

• torn collateral ligaments difficult to identify because often encased in edematous connective tissue

• menisci often displaced from normal positions and folded cranially or caudally

knowledge of normal origins and insertions of ligaments in joint required:

collateral ligaments

meniscocapsular ligaments

structures commonly injured with multiple ligament derangement of the stifle joint

note loss of cranial and caudal cruciate ligaments and disruption of the medial restraints

multiple ligament injuries

common triad of injuries includes:

• cranial and caudal cruciate ligament tears

• failure of primary and secondary medial restraints

• peripheral medial meniscal tears

prognosis is fair

deranged stifle

when there are multiple ligamentous injuries

often with meniscal injury

• resulting in luxation of stifle joint

deranged stifle

FOR THE LOVE OF GOD, KNOW THIS IMAGE

meniscal tear image

meniscal release - locations:

A. transection of meniscotibial ligament

B. transection of midbody of meniscus

meniscal release

what does meniscal release mean:

“protecting” medial meniscus following surgical stabilization of stifle

developed in association with TPLO

meniscal release

• controversial based on effects on meniscus and cartilage and uncertain efficacy

by transecting meniscus

• function of meniscus is compromised by elimination of hoop stresses

with midbody meniscal release or transection of meniscotibial ligament:

• femoral condyle increases contact with articular cartilage of tibial plateau

  • contributes to osteoarthritis

• impairs functions of meniscus to provide stability and congruence

no clinical studies demonstrate efficacy of meniscal release in decreasing incidence of post TPLO meniscal injury; but technique remains in widespread use

medical management of meniscal injuries:

conservative treatment is not an option!

• continued back-and-forth sliding of torn meniscus:

  • causes severe pain

  • will not improve with conservative management

accelerates DJD

conservative meniscal injuries tx

rest-plus or minus splint?

may be appropriate in stable joint

surgical treatment of meniscal injuries

1) partial meniscectomy

2) primary repair of peripheral meniscal injuries

3) total meniscectomy

partial meniscectomy can be done by lateral approach:

• removal of caudal horn

• bucket handle tear excision

medial meniscectomy is easiest to perform through a medial surgical approach

partial meniscectomy:

removal of torn section of meniscus

• experimentally: partial meniscectomy carries less morbidity than a total meniscectomy

• treatment of choice for bucket handle tears of medial meniscus

primary repair of peripheral meniscal injuries

in human orthopedics: some surgeons advocate primary repair of torn meniscal body

in dogs: primary repair reserved for peripheral tears!

• uncommon!

• difficulty in suturing meniscal body tears in dogs

• low morbidity associated with partial meniscectomy

repair with absorbable interrupted sutures

• allowed meniscocapsular tissue to heal

• challenging!

meniscal injuries treatment - general

damaged meniscus may not heal (likely not!)

total or partial removal may be indicated

total meniscal removal induces severe DJD in stifle!

total meniscectomy

when is a total meniscectomy indicated?

only when peripheral rim of meniscus is so damaged that primary suturing of meniscocapsular tissue is not possible

the more meniscal tissue removed the more rapidly OA develops