Posterolateral ankle ligament injuries affect ankle stability: a finite element study

Abstract

BackgroundWe have already discovered 23 patients during the work of the outpatient department and operations whose unstable signs on the posterolateral ankle. The anterior drawer test demonstrated normal during the physical examinations while the spaces of the posterior tibiotalar joints increased in stress X-ray plain films. ATFL intact and posterolateral ligaments lax were found during operations too. It is important to make existence claims and illuminate the mechanism of posterolateral ankle instability.MethodsA finite element model of the ankle was established for simulating to cut off posterolateral ligaments in turn. Ankle movements with tibia rotation under load on five forefoot positions were simulated as well.ResultsThe difference values with tibia external rotation were negative, and the positive results occurred with tibia internal rotation. The tibia-talus difference values in some forefoot positions were 2 ~ 3 mm after PTFL together with CFL or/and PITFL were cut off. The tibula-talus difference values were 2.21 ~ 2.76 mm after both PTFL and CFL were cut off. The tibia-fibula difference values were small. The difference values increased by 2 ~ 5 mm after cutting off the PITFL.ConclusionsPosterolateral ankle ligaments, especially CFL and PITFL, play a significant role in maintaining ankle stability. The serious injuries of both CFL and PITFL would affect posterolateral ankle stabilities. PITFL was important to subtalar joint stability.

The influence of sagittal angle of posterior malleolus fracture on ankle joint stability：a retrospective study of 87 cases

“…The current studies con rmed that ankle joint was a joint composed of tibia, bula, talus and shin bone [9]. With an incidence of about 10%, ankle fracture was a common injury in all fractures.…”

T2‐Mapping evaluation of early cartilage alteration of talus for chronic lateral ankle instability with isolated anterior talofibular ligament tear or combined with calcaneofibular ligament tear

“…With inversion loading, combined ATFL and CFL sectioning result in increased abnormal range of motion when compared with intact and ATFL‐sectioned ankles. In addition, a finite element study by Zhu et al suggested that the injury of CFL may affect posterolateral ankle stabilities. These findings might be suggestive of much more instability of the ankle for combined ATFL and CFL tear than isolated ATFL tear, which could explain our result as to why a combined ATFL and CFL tear resulted in much larger and severer cartilage degeneration than isolated ATFL tear.…”

Cartilage Matrix Changes in Hindfoot Joints in Chronic Ankle Instability Patients After Anatomic Repair Using T2‐Mapping: Initial Experience With 3‐Year Follow‐Up

“…30 Additionally, a finite element study reported that the injury of CFL may affect posterolateral ankle stability. 31 Abnormal kinematics consequently predispose the cartilage to degeneration and injury. 7 In our study, cartilage subregions with elevated T2 values could be found in medial and posterior regions of talar dome and medial pSTJ subregions.…”