An avulsion fracture is where a tendon or ligament is torn off a bone, taking a fragment of the bone away with it.
Page updated July 2024 by Dr Sheila Strover (Clinical Editor)
What is the importance of an avulsion fracture?"
The presence of an avulsion fracture on X-ray indicates that there has been traction damage to soft tissues, usually from a ligament being pulled away from the bone - but the tiny bony fragment may be easily missed on X-ray.
Common avulsions include tibial tubercle avulsion and tibial spine avulsion. Avulsion of the anterolateral ligament is important not to miss.
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Quote from peer-reviewed paper:
"....The Segond fracture is commonly regarded as pathognomonic for significant intra-articular pathology such as an anterior cruciate ligament (ACL) tear. There is worsened rotatory instability in patients with concomitant ACL tear and Segond fracture...."
Citation: Phua SKA, Lim JY, Li T, Ho SWL. The segond fracture: A narrative review of the anatomy, biomechanics and clinical implications. J Clin Orthop Trauma. 2023 Feb 13;38:102127. doi: 10.1016/j.jcot.2023.102127. PMID: 36860993; PMCID: PMC9969264.
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Quote from peer-reviewed paper:
"Anterior cruciate ligament (ACL) avulsion fractures....result in significant disability if left untreated....[and] are caused by forceful hyperextension of the knee or by a direct blow over distal end of femur with the knee flexed."
Citation: Sundararajan SR, Rajasekaran S, Bernard SL. Displaced anterior cruciate ligament avulsion fractures: Arthroscopic staple fixation. Indian J Orthop. 2011 Jul;45(4):324-9. doi: 10.4103/0019-5413.82336. PMID: 21772625; PMCID: PMC3134017.
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Quote from peer-reviewed paper:
"PCL [posterior cruciate ligament] avulsion fractures are rare injuries that can lead to significant morbidity when not recognized and treated properly"
Citation: Katsman A, Strauss EJ, Campbell KA, Alaia MJ. Posterior Cruciate Ligament Avulsion Fractures. Curr Rev Musculoskelet Med. 2018 Sep;11(3):503-509. doi: 10.1007/s12178-018-9491-2. PMID: 29869136; PMCID: PMC6105473..
How is an avulsion fracture treated?"
Most avulsion fractures will heal if the knee is immobilised and rested.
Where healing does not occur, the bone fragment may be reattached with a staple.
Forum discussions
- Mislead diagnostic
Patients discussing MRI scans and avulsion fractures.