Knee iSAWE 16

Question

A 49 year old man has medial knee pain and stiffness. He injured the knee skiing a year earlier.

Knee iSAWE 16, AP radiograph of the knee
AP radiograph of the knee. Image by Hellerhoff, Wikimedia Commons, CC BY-SA 4.0.
  1. Describe the radiograph.
  2. Describe the anatomy and grading of MCL injuries.
  3. How do you manage an acute MCL injury, alone and with an ACL tear?

Answer

Radiograph

  • Ossification adjacent to the medial femoral condyle
  • Pellegrini-Stieda lesion, calcification at the femoral MCL origin after injury

Anatomy

  • Superficial MCL from medial epicondyle to the tibia about 6 cm below the joint
  • Deep MCL (meniscofemoral and meniscotibial ligaments)
  • Posterior oblique ligament
  • Primary restraint to valgus at 30 degrees of flexion

Grading

GradeOpening at 30 degrees
IUnder 5 mm, firm end point
II5 to 10 mm, end point present
IIIOver 10 mm, no end point
  • Valgus laxity in full extension implies cruciate and posteromedial injury

Management

  • Isolated injuries heal well with a hinged brace and early motion
  • Tibial side and Stener like lesions (sMCL above pes anserinus) heal poorly, repair them
  • With ACL tear, brace the MCL for 4 to 6 weeks, then reconstruct the ACL
  • Repair or reconstruct the MCL if valgus laxity persists in extension
  • Pellegrini-Stieda lesions rarely need excision

Related pages

Author Contributions

Orthofracs team

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.