Preliminary Study Of T2 Mapping To Quantitatively Evaluate The Changes Of Cartilage In Patients With Chronic Lateral Ankle Instability

Objective:T2 mapping was applied to quantitatively evaluate the alteration of talar trochlear cartilage in patients with chronic lateral ankle instability(CLAI),Additionally,the changes of talar trochlear cartilage T2 values in patients with isolated anterior talofibular ligament(ATFL)tear and combined with calcaneofibular ligament(CFL)tears were explored.These findings provided a reference for the early diagnosis of articular cartilage injury,making it easier to choose clinical treatment options and successfully halt the development of post-traumatic osteoarthritis.Methods:To participate in the study,25 healthy volunteers and 29 patients with CLAI who were clinically confirmed in our hospital between June 2021 and February 2023 were collected,all participants underwent GE signa 3.0T ankle routine magnetic resonance imaging(MRI)scan and T2 mapping scan.The image is uploaded to picture archiving and communication systems after capture,and the original T2 mapping image is uploaded to the post processing workstation(GE ADW4.6),and original image of T2 mapping is then reconstructed using the built in software package of the post-processing workstation to obtain the T2 mapping pseudo color image.Two radiologists diagnosed whether the ATFL and CFL were injured by routine ankle MRI scan and divided the patients with CLAI into the group with isolated ATFL tear(n=18)and the group with combined ATFL and CFL tears(n=8).In the coronal position of the ankle,the talar trochlear cartilage is divided into two equal parts,with the tibial side defined as medial and the fibular side defined as lateral;in the sagittal position of the ankle,the talar trochlear cartilage is divided into three equal parts,all of which are divided into the anterior,central,and posterior parts of the talus.Talar trochlear cartilage was divided into six compartments according to the above principles of division: medial anterior(MA),medial center(MC),medial anterior(MP),lateral posterior(LA),lateral anterior(LC)and lateral anterior(LP).The T2 values of the above six cartilage compartments were measured at the medial and lateral cartilage levels of three consecutive talus,and the average T2 value of each cartilage compartment was calculated,and the average T2 values at six compartments were the T2 values of talar trochlear cartilage(TTC).Differential analysis of the T2 values in the same compartment of the talar trochlear cartilage between those with CLAI and healthy controls was performed by independent Student’s t-test;One-way analysis of variance was used to analyze the variability of T2 values in the same cartilage compartment between three groups: the group with isolated ATFL tear,the group with combined tears of the ATFL and CFL,and the healthy control group,and LSD tests were used to perform multiple comparisons between groups.Results:1.Comparison of baseline data: There was no significant difference in the baseline data(sex,age,BMI and symptom duration)between the CLAI group and the healthy control group(P>0.05);there was no significant difference in the baseline data(sex,age,BMI and symptom duration)of the isolated ATFL tear group,ATFL combined with CFL tears group and healthy control group(P>0.05).2.Comparison of the mean T2 of talar trochlear cartilage in the CLAI group and the healthy control group: The average T2 values of MA,MC,MP and TTC were higher in patient with CLAI than in healthy controls(P < 0.05).3.Comparison of the average T2 of talar trochlear cartilage in the isolated ATFL tear group,ATFL combined with CFL tears group and healthy control group: The average T2 values of MA,MC,MP,TTC were higher in the isolated ATFL tear group than in the healthy control group;The average T2 values of MA,MC,MP,LC,LP,TTC were higher in the ATFL combined with CFL tears group than in the healthy control group(P <0.05);Moreover,the average T2 values of MC,MP,LC,and TTC were higher in the ATFL combined with CFL tears group than in the isolated ATFL tear group(P < 0.05).Conclusion:Patients with CLAI are at potential risk of talar trochlear cartilage tear,mainly in the medial cartilage compartments.CLAI with isolated ATFL tear are at potential risk of medial talar trochlear cartilage tear;ATFL combined with CFL tears are at greater risk of potential talar trochlear cartilage tear in patients with CLAI than isolated ATFL tear.As a sensitive quantitative biochemical MRI technique,T2 mapping can non-invasively diagnose joint cartilage tear early,which is conducive to the selection of clinical treatment methods for CLAI and detection of disease progression,thereby effectively preventing the development of post-traumatic osteoarthritis.