Arthroscopic Quantification of Syndesmotic Instability in a Cadaveric Model

Effect of Sequential Sectioning of Ligaments on Syndesmotic Instability in the Coronal Plane Evaluated Arthroscopically

“…Instability measured along the anterior margin of the incisura requires not only complete syndesmotic disruption but also additional injury to the deltoid ligament. This corroborates other cadaveric and in vivo studies 7,8 that also found that diastasis measured at the posterior aspect of the incisura was greater than that measured at the anterior aspect, independent of the extent of ligamentous transection.…”

Role of the Deltoid Ligament in Syndesmotic Instability

“…In the intact syndesmosis as well as in progressive stages of ligamentous transection, earlier studies 8,9 identified greater coronal plane diastasis when measured at the posterior third of the incisura as compared to anterior third. Also, a prior cadaveric study 17 demonstrated that the posterior third of the distal tibiofibular articulation became unstable when the AITFL, IOL, and PITFL were injured.…”

“…A prior cadaveric study 9 that arthroscopically evaluated the syndesmosis after isolated deltoid transection did find a significant associated increase in tibiofibular diastasis in the posterior third of the incisura (1.25 mm), but not in the anterior third (0.8 mm). Notably, this previous study 9 used the external rotation test to stress the syndesmosis rather than the lateral hook test, the latter of which may be more reliable when assessing the distal tibiofibular articulation. 23 Equally important, in our own experience, the external rotation test tended to markedly narrow the tibiotalar joint and extrude the arthroscopic camera anterolaterally during stress testing, limiting its utility when arthroscopically evaluating the syndesmosis.…”

“…4,11 Advances in ankle arthroscopy allow direct inspection of the syndesmosis, 5,15,24,25 affording the opportunity to directly visualize even subtle syndesmotic instability. 9,16,27 Variable anatomic locations within the distal tibiofibular joint have historically been used to diagnose syndesmotic instability, including the center, anterior, and posterior aspect of the incisura. 9,17,27 There is a paucity of literature, however, exploring the role of the DL in conferring stability to the injured syndesmosis.…”

“…9,16,27 Variable anatomic locations within the distal tibiofibular joint have historically been used to diagnose syndesmotic instability, including the center, anterior, and posterior aspect of the incisura. 9,17,27 There is a paucity of literature, however, exploring the role of the DL in conferring stability to the injured syndesmosis. 3,21 The purpose of this study was to arthroscopically evaluate the role of the DL in stabilizing the syndesmosis in the coronal plane by measuring both the anterior and posterior third diastasis of the distal tibiofibular articulation in a cadaveric model.…”