CME OnDemand: 2022 AOFAS Annual Meeting-Biomechanical Study of Syndesmotic Stability in AITFL and PITFL Injury Models

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This study aimed to evaluate the syndesmotic stability in anterior inferior tibiofibular ligament (AITFL) and posterior inferior tibiofibular ligament (PITFL) injury models. The researchers used cadaveric legs and applied traction and rotational forces to assess the biomechanical changes. The results showed that the AITFL and PITFL injury models significantly increased fibular rotation angle (FRA) and anterior tibiofibular diastasis (aTFD) compared to the intact model in anterior traction force, external rotation force, and internal rotation force tests. However, in models with syndesmotic fixation, FRA and aTFD did not differ significantly from the intact model. This suggests that syndesmotic fixation can restore stability in AITFL and PITFL injuries. Additionally, the study found that PITFL injury played an important role in stabilizing the syndesmosis during internal rotation of the ankle. The authors concluded that for severe syndesmosis injuries with PITFL rupture, a combination of syndesmotic fixation and anterior ST (aST) fixation is sufficient to restore stability, and posterior ST (pST) fixation may not always be necessary. However, the study had limitations, such as not simulating axial load or in vivo ligament injury patterns. The study emphasized the importance of considering PITFL injury in the treatment of syndesmosis instability. Previous studies mainly focused on AITFL and interosseous membrane (IOM) injuries, while the effects of PITFL injury remained unclear. This study provided insights into the biomechanical effects of PITFL injury and its treatment. Overall, syndesmotic stability can be restored with syndesmotic fixation and aST fixation for PITFL rupture.

Asset Subtitle

Katsunori Takahashi, Atsushi Teramoto, MD, Yasutaka Murahashi, Kosuke Shiwaku, Shogo Nabeki, Tomoaki Kamiya, MD, Kota Watanabe, Toshihiko Yamashita

Keywords

syndesmotic stability

anterior inferior tibiofibular ligament

posterior inferior tibiofibular ligament

biomechanical changes

fibular rotation angle

anterior tibiofibular diastasis

syndesmotic fixation

ankle stability

PITFL injury

syndesmosis instability