Knee Ligament Injuries by sammyc2007

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									Knee Ligament
Injuries
                Overview
   Ligament Anatomy
   Biomechanics
   Ligament Specific
     Epidemiology
     Classification

     Clinical exam

     Imaging

     Tx
Ligament Anatomy
   Type 1 collagen (70%)
   Elastin
   Extracellular matrix
   Hierarchical structure
   Fibrils > fibres >subfascicular unit
    >fasciculus
   Longitudinal fasciculi (MCL, LCL)
   Helical fasciculi (ACL, PCL)
Anatomic Features
   Bonding
   Crimping
   Random collagen alignment
   Complex blood supply
   Diffusion from synovium
   Proprioception and nociception
Biomechanics
   Laxity
   Stiffness
   Strength
   Viscoelastic behavior (creep,
    stress relaxation, hysteresis)
   Dynamic properties
Ligament healing
   Immobilization
     Loading dramatically affects
      recovery of normal mechanical
      properties
     Decrease strength

     Insertion site vs. midsubstance

   Exercise
       Favourable effect
Epidemiology
   Increasing incidence
   Combined injuries common
   Females > males
   Conditioned vs. unconditioned
Conditioned
Unconditioned
ACL Anatomy
     Intracapsular
     Extrasynovial
     Varied blood supply
     FAMPLE
     Origin / Insertion
ACL Function
   Limit anterior displacement
   20 restraint rotation
   20 restraint varus / valgus in
    extension
Mechanism / Hx
   Usually noncontact
   Change direction
   Stop / jump
   Audible “pop”
   Instability
   Swelling
General Ligament Exam
        Difficult acutely
        Early exam beneficial
        Pt. relaxed
        Displacement
        Endpoint quality
        Compare
ACL Exam
      Lachman – best
      Pivot Shift – diagnostic
      Anterior drawer – chronic
       tear
      Associated injuries
ACL Imaging
   XRAY
     R/O #
     ACL avulsion

     Segond #



   Arthrography - poor
   Arthroscopy - gold standard
ACL MRI

   95% accurate
   Low signal intensity
   Saggital view
   Acute injury high signal intensity
    on T2 image
   Bone bruising
ACL Tx
   Pt selection
   Operative vs. Non-operative
     Demand level
     Modify lifestyle

     ACL dependent

     Other lesions
Non-operative
   Acutely – splint & crutches
   Early active ROM
   Closed chain WB to strengthen
   Avoid high risk
   Functional bracing controversial
Operative
               Pt selection
                 High demand
                 Young

                 Good ROM

               Open vs.
                endosopic
               Learning curve
Graft
   Auto vs. allo
   Collagen lattice
   Resorption – revascularization –
    restructuring
   Bone-patellar tendon-bone
   Semitendinosus/gracilis
   tensioning
Rehab

   Closed kinetic chain strengthening
   Acutely fixation weak
   Graft weakest 6-12 wks
   Outcome
       >90% stable 3-5 yrs
MCL Anatomy
    Origin – femoral condyle
    Insertion – 4cm below joint line
    + posterior obl. Lig.
    + middle capsular ligament
    Parallel collagen
MCL
    Most common isolated ligament
     injury
    Valgus force
    Post. Obl. Lig. damage with
     rotn. injury
    Associated ACL common
MCL exam
   Valgus force
   Flex. 300 – isolated
   Extension
       Assoc. POL,ACL,PCL
   5-8 mm difference significant
   Swelling
       Hemarthrosis vs. soft tissue
MCL Tx
    Non-surgical
    RICE
    Bracing
    Strengthening
    Functional brace
MCL Classification / Tx
      Grade 1 : 1-5 mm
          Symptomatic Tx
      Grade 2 : 6–10 mm
          Hinge brace 2-3 wks
      Grade 3 : 11-15 mm
          Hinge brace 3-4 wks
      Physio
PCL Injury
   1.5 x ACL strength
   5% all knee lig. inj.
   10 restraint post. translation tibia
   Forced flexion
   Dashboard
   Associated injuries
PCL
   Pain
   Usually stable
   Posterior subluxation
   Medial & patellofemoral OA
PCL exam
   Posterior drawer test –best
       Grade I - III
   Quadriceps active test
   Post sag sign
Non-operative
   Aggressive rehab
   Focus quadriceps
   No support for bracing
   closed kinetic chain
   Open kinetic chain extension
    avoided
   90% quads strength prior to normal
    athletics
PCL Tx
   Repair :
     Associated posterolateral corner
     Associated ACL / MCL

     Grade 3 Drawer test

     Bony avulsion

     20% athletes with isolated injury
      require repair
Operative Repair
   Require good ROM pre-op
   Graft > 40mm
   No good rehab protocol
Posterolateral Complex
        Combination of Structures
          ITB
          biceps femoris

          fibular collateral

          Popliteus complex

          Capsule

          etc
Posterolateral corner
   Usually assoc with:
     PCL
     Knee dislocation

     Rarely ACL

   Instability esp descending inclines
   Peroneal N. inj. 10%
   pain
Biomechanical
    Increased:
      External tibial rotation
      Varus rotation

      Posterior tibial translation
Exam
   Swelling / bruising
   Gait : Varus thrust
   AP translation > 300 than 900
   Best tests:
     Varus stress opening > 300 than 00
     Prone external rotation test

   Other tests
Operative
   10 Repair
     Acute injury
     Bony avulsion

   Reconstruction
     Biceps tenodesis / arcuate lig
      advancement : mixed results
     Graft - results pending

   Varus malalignment - HTO
Conclusion
   Common injuries
   Easily missed
   Large area
   Ongoing research

								
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