LATERAL COLLATERAL LIGAMENT INJURY(LCL)

06 Oct LATERAL COLLATERAL LIGAMENT INJURY(LCL)

• Also known as fibular collateral ligament
• Origin – 3.1 mm posterior and proximal to lateral femoral epicondyle and posterior and proximal to popleteus
• insertion – anterolateral fibular head, most anterior structure followed – popleteofibular ligament – biceps femoris
• Isolated injury extremely rare less than 2%
• Pathophysiology
  • trauma
  • associated injury
    • PLC Injury
    • ACL injury
    • PCL injury

ANATOMY

• Cord like structure 2-3 mm thick, 5 mm wide and 67mm long
• Biomechanics
  • Function
    • primary restraint to varus force at 5_⁰ and 30⁰
    • secondary restraint to posterolateral rotation with <50⁰ flexion
  • tight in extension and lax in flexion
  • strength : 750N

CLASSIFICATION

• GRADE 1- <5MM Lateral joint opening
• GRADE 2 – 6 TO 10 mm lateral joint opening
• GRADE 3- >10 MM lateral joint opening

CLINICAL PRESENTATION

• Symptoms
  • instability
  • difficulty negotiating stairs
  • swelling and tenderness
• Examination
  • swelling, lateral joint line tenderness and LCL insertion tenderness
  • virus thrust gait
  • CPN injury
  • varus stress
    • 30⁰ flexion -instability (isolated injury to LCL)
    • 0⁰ and 30⁰ flexion – instability(ACL/PCL Injury)
    • Dial test – . >10⁰ external rotation at 30⁰ flexion(Posterolateral corner injury)

INVESTIGATION

• XRAY
  • Varus and valgus stress view of knee – AP and lat view will show lateral joint line opening
• MRI
  • medial condyle contusion with LCL tear
  • gold standard

TREATMENT

• Nonoperative
  • immobilisation and rehabilitation for 6 to 8 weeks in grade 1 and 2 injury
• operative
  • isolated LCL reconstruction in grade 3 tear in varus instability
  • LCL and PLC reconstruction if rotatory instability