ABSTRACT
Objective@#To quantitatively assess biochemical alterations in the cartilage of the subtalar and midtarsal joints in chronic lateral ankle instability (CLAI) patients with isolated anterior talofibular ligament (ATFL) injuries and combined calcaneofibular ligament (CFL) injuries using MRI T2 mapping. @*Materials and Methods@#This study was performed according to regulations of the Committee for Human Research at our institution, and written informed consent was obtained from all participants. Forty CLAI patients (26 with isolated ATFL injuries and 14 with combined ATFL and CFL injuries) and 25 healthy subjects were recruited for this study. All participants underwent MRI scans with T2 mapping. Patients were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system. The subtalar and midtarsal joints were segmented into 14 cartilage subregions. The T2 value of each subregion was measured from T2 mapping images. Data were analyzed with ANOVA, the Student’s t test, and Pearson’s correlation coefficient. @*Results@#T2 values of most subregions of the subtalar joint and the calcaneal facet of the calcaneocuboid joint in CLAI patients with combined CFL injuries were higher than those in healthy controls (all p 0.05). Moreover, T2 values of the medial talar subregions of the posterior subtalar joint in patients with combined CFL injuries showed negative correlations with the AOFAS scores (r = -0.687, p = 0.007; r = -0.609, p = 0.021, respectively). @*Conclusion@#CLAI with combined CFL injuries can lead to cartilage degeneration in subtalar and calcaneocuboid joints, while an isolated ATFL injury might not have a significant impact on the cartilage in these joints.
ABSTRACT
Objective To compare T2* value in healthy and diseased achilles tendons (AT) using 3D-ultra-short echo time (UTE),and to analyze the correlation between T2* value and clinical scores.Methods Fifteen patients (patients group) and ten volunteers (control group) were included and underwent an MR scan with UTE sequence.The T2* value of four ROI in AT were calculated.Independent sample t-test was used to compare the differences of T2* value between two groups.The correlation of T2* values with the American Orthopaedic Foot and ankle society ankle hindfoot scale (AOFAS) and achilles tendon total rupture score (ATRS) were analyzed.Results The T2* value of four ROI were statistically significantly higher in patients group than those of control group.There were negative correlation between T2* and AOFAS or ATRS scores (r=-0.92,-0.90,both P＜0.01).Conclusion The T2* value of pathologic AT increases.The quantitative MRI UTE-T2* can evaluate AT from the biochemical structure and correlates with clinical outcomes,which is helpful to diagnose AT in the early stage.
ABSTRACT
Objective To quantitatively analyze the histological and MR images of repaired tissue (RT) following microfracture for knee joint osteochondritis dissecans (OCD) in rabbit models at different time points,make comparisons with the RT performances of joint debribement,explore the efficiency of the microfracture treatment for OCD.Methods Twenty-seven New Zealand rabbits were randomly assigned into 3 groups (sacrificed at the end of 3,5 and 7 weeks post-operation respectively),with 9 in each group.For each rabbit,one knee joint was made into an OCD model.In each group,6 were for microfracture treatment,and the other 3 were for joint debridement as control.MR scan,which mainly included sequences of 3D double echo steady state sequence (3D-DESS) and T2-mapping,was taken at 3,5 and 7 weeks postoperation.The thickness index and T2 value index of RT were calculated and T2-mapping of repaired region was drafted.Then the operation sites were removed to make histological sections of HE and Masson staining.The modified O' Driscoll score system was employed to make semi-quantitative evaluation for the histological performance of RT.Comparisons were made with respect to MR and histological findings between two treatments at each time point using unpaired Student t test.Effects of two treatments were evaluated longitudinally by comparing the results of three time points using one-way ANOVA.Results The post-operation thickness indexes of two groups increased gradually (F =33.940,28.841,P ＜ 0.05),T2 value indexes decreased (F =80.183,206.206,P ＜ 0.05),and O'driscoll scores increased gradually (F =29.867,17.167,P ＜ 0.05).At each time point,the thickness index of microfracture was higher than that of debridement group(3-week:0.743 ±0.048 vs 0.624 ±0.013,t =4.077 ;5-week:0.813 ±0.031 vs 0.734 ±0.015,t =4.107 ; 7-week: 0.972 ± 0.064 vs 0.777 ± 0.039,t =4.782 ; P ＜ 0.05),and the defects of microfracture in 7-week group were almost fully recovered while the defects of the debridement in 7-week group were not.The T2 value index of microfracture group was lower than that of debridement group at 3-week point(1.338 ±0.043 vs 1.510 ± 0.009,t =6.583,P ＜ 0.05),but it was higher than that of debridement group at 5-week and 7-week points (5-week: 1.284 ± 0.097 vs 1.116 ± 0.068,t =2.663 ; 7-week: 0.916 ± 0.036 vs 0.843 ± 0.016,t =3.283 ; P ＜ 0.05).The O'Driscoll score of microfracture group was higher than that of joint debridement at every time point(3-week:7.167 ±0.753 vs 4.667 ±0.577,t =5.000;5-week: 9.833 ± 1.169 vs 7.667 ± 0.577,t =2.960 ; 7-week: 11.167 ± 0.753 vs 8.333 ± 1.155,t =4.520 ; P ＜ 0.05).For microfracture group,the RT was mainly repaired by fibrocartilage and got matured gradually with more production of well-distributed collagen fibrils ; while for joint debridement group,the RT was mainly repaired by fibrous and scar tissue.Conclusions The post-operation repairing thickness and tissue composition of microfracture for OCD are superior to that of joint debridement.MR 3D-DESS and T2-mapping can show the thickness and tissue composition of the RT after OCD treatments,provide effective evaluation of repairing conditions,and they are of great importance on the OCD post-op follow-up.