Tibial Spine Avulsion


  • With the same mechanism that would rupture an ACL or PCL in an adult (twisting on a semiflexed knee, hyperextension), in the skeletally immature can result in a tibial spine avulsion fracture


  • Similar to ACL rupture:
    • Swelling (may well have a haemarthrosis)
    • Reduced range of motion
    • Pain
    • Difficulty weightbearing
    • Feeling of or actual instability
    • Positive Lachman’s test
  • X-ray findings
    • Often small sliver of bone displaced from the tibial spine (which is often significantly more impressive on CT / MRI)
    • May have a lipohaemarthrosis (as it is an intra-articular fracture)


  • Displaced fractures require prompt surgical management, so if suspicious of cruciate ligament injury in a child, need to x-ray
  • Undisplaced fractures may be managed non-operatively, with a period of splinting and restricted activity