O'Donoghue unhappy triad

O'Donoghue unhappy triad or terrible triad often occurs in contact and non-contact sports, such as basketball, football, or rugby, when there is a lateral force applied to the knee while the foot is fixated on the ground. This produces an abduction-external rotation mechanism of injury ("pivot shift" in non-contact sports).

Pathology

The O'Donoghue unhappy triad comprises three types of soft tissue injury that frequently tend to occur simultaneously in knee injuries. O'Donoghue described the injuries as:

The triad has subsequently been revisited considering the arthroscopic findings in patients with both ACL and MCL injuries, where a lateral meniscal injury is more common than injury to the medial meniscus 2. Mechanistically this makes more sense during the pivot shift movement, as the lateral tibiofemoral compartment is compressed, causing failure of the lateral meniscus.

History and etymology

The unhappy triad is named after D H O'Donoghue, American orthopedic surgeon, who described it in 1950 4.

Knee pathology

The knee is a complex synovial joint that can be affected by a range of pathologies:

Article information

rID: 1749
Section: Signs
Synonyms or Alternate Spellings:
  • Unhappy medial triad
  • O'Donoghue triad
  • Unhappy triad
  • O'Donoghue's triad

ADVERTISEMENT: Supporters see fewers/no ads

Cases and figures

  • MCL strain; bucke...
    Case 1: showing all three injuries
    Drag here to reorder.
  • Case 2
    Drag here to reorder.
  • Case 3
    Drag here to reorder.
  • <br />
    Case 4
    Drag here to reorder.
  • Case 5
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.