medial collateral ligament (MCL) sprain/tear

Classification

• application of valgus force to the knee flexed at 30 degrees
  • grade 1: results in joint opening (gap) < 5 mm
  • grade 2: results in a 5-9 mm joint opening (gap) corresponding to a tear of the same length
  • grade 3: results in a > 9 mm joint opening (gap)

Etiology

• direct blow to the outside of the knee
• severe outward twisting with foot planted during athletic activity

Epidemiology

• common cause of traumatic knee injury

Clinical manifestations

• medial knee pain
• knee instability
  • valgus stress test of the knee flexed 30 degress
  • the medial collateral ligament is the main stabilizer
  • an MCL tear reveals a gap
• medial joint line tenderness, joint swelling
  • tenderness over the medial collateral ligament
  • rarely large effusion

Radiology

• magnetic resonance imaging (MRI): grade 3 MCL tears, candidates for surgery

Management

• medical management for most grade 1 & grade 2 MCL tears
  • RICED: brace, crutches, physical therapy
• surgery may be necessary for grade 3 MCL tears if laxity persists after physical therapy & confirmation by MRI

More general terms

• knee injury, traumatic

Additional terms

• medial collateral ligament (MCL)