Patellar tendon rupture

Background

• Occurs via forceful contraction of quadriceps muscle or falling on flexed knee
• Quadriceps rupture proximal to the patella while patellar tendon ruptures are distal
• Typically occur 2cm from insertion on patella
• Patellar tendon rupture
  • Pts <40yr w/ history of tendinitis or steroid injections
• Quadriceps tendon rupture
  • Pts >40yr

Clinical Features

• Sudden "pop" or tearing
• Diffuse swelling
• Defect may be palpable above or below the patella
• Partial tears lead to difficulty extending the knee
• Complete tears lead to absent straight leg raise while supine or extension of the knee again

Associated Conditions

• Patella fracture
• Patella dislocation
• Patellar Tendinitis (Jumper's knee)

Work Up

• Ultrasound
  • Separation of the tendon can be visualized
• X-ray
  • Patella alta (or high-riding patella) is consistent with patella tendon rupture
  • Patella baja/infera (or low-riding patella) is consistent with quadriceps tendon rupture

Management

• Ortho consult in the ED
• Operative repair advised within 7 days

Source

• Tintinalli
• Uptodate
• Wheeless' Textbook of Orthopaedics