(Fig 3-B.31) Anterolateral rotary instability

https://youtu.be/Y9CU2wiAixM

https://youtu.be/6WOItzqJj1g

 

📌 Anterolateral rotatory instability (ALRI)

• A varus force combined with internal rotation of the tibia can cause an ACL tear. 
• It may be linked to a Segond fracture (avulsion of the lateral tibial rim where the lateral capsular ligament attaches)
  (Magn Reson Imaging Clin N Am 22 (2014) 557–580).

 

• ALRI is a combined anterior translation and internal rotation movement of the tibia that occurs after injury to the ACL and anterolateral structures of the knee like the lateral capsular ligament and arcuate complex
  (Radiol Clin N Am 40 (2002) 203–216).

 

• The resulting force vector causes anterior tibial translation, varus angulation, internal tibial rotation, injury to the ACL, FCL, arcuate complex, and popliteus muscle
  (Magn Reson Imaging Clin N Am 22 (2014) 621-648).

 

• ALRI is often associated with a characteristic anterolateral meniscus tear, as well as other meniscus injuries
  (Radiographics 20 Spec No (2000) S91-102).

 

• The Segond fracture fragment is thin, ovoid, vertically oriented along the lateral tibial plateau posterior to Gerdy's tubercle at the tibial insertion of the anterolateral ligament (ALL)/lateral capsular ligament
  (Skeletal Radiol 45 (2016) 1635–1647).

 

• MRI studies show the posterior fibers of the iliotibial band and the ALL/lateral capsule attach to the Segond fracture in most cases
  (Am J Sports Med 45 (2017) 2247-2252).

 

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#ACLTear, #SegondFracture, #AnterolateralRotatoryInstability, #AnteriorTibialTranslation, #InternalTibialRotation, #LateralCapsularLigamentInjury, #ArcuateComplexInjury, #AnterolateralMeniscusTear, #AnterolateralLigament, #IlliotibialBandAttachment