渡邉 翔太郎

BACKGROUND: We aimed to evaluate the intra- and interrater measurement reliability of the lateral ankle ligament attachment locations using three-dimensional magnetic resonance imaging. METHODS: We analysed 54 participants with a mean age of 43 years who underwent three-dimensional ankle magnetic resonance imaging and had normal lateral ligaments. Bony landmarks of the distal fibula, talus, and calcaneus were identified in the reconstructed images. The centers of the anterior talofibular ligament and calcaneofibular ligament attachments were also identified. The distances between the landmarks and attachments were measured. Two raters performed the measurements twice, and intra- and interrater intraclass correlation coefficients were calculated. RESULTS: The intrarater intraclass correlation coefficient values were between 0.71 and 0.96 for the anterior talofibular ligament attachment measurements and between 0.77 and 0.95 for the calcaneofibular ligament attachments. The interrater intraclass correlation coefficient was higher than 0.7, except for the distance between the anterior talofibular ligament superior bundle and fibular obscure tubercle. The fibular attachment of a single-bundle anterior talofibular ligament was located 13.3 mm from the inferior tip and 43% along the anterior edge of the distal fibula. The superior and inferior bundles of the double-bundle ligament were located at 43% and 23%, respectively. The calcaneofibular ligament fibular attachment was 5.5 mm from the inferior tip, at 16% along the anterior edge of the distal fibula. CONCLUSION: The measurements of anterior talofibular ligament and calcaneofibular ligament attachment locations identified on three-dimensional magnetic resonance imaging were sufficiently reliable. This measurement method provides in vivo anatomical data on the lateral ankle ligament anatomy.

OBJECTIVE: To assess articular cartilage degeneration in anterior cruciate ligament (ACL) reconstructed knees as detected by MR T1rho and T2 mapping relative to controls and longitudinally at 3 months and 1 year after ACL reconstruction (ACLR). DESIGN: Twenty-five patients with acute ACL injury were enrolled (13 women and 12 men; mean age 30.8), and 14 healthy controls were selected by sex and age matching. The affected knees of the ACLR participants were imaged using a 3.0T magnetic resonance (MR) scanner 3 months and 1 year after ACLR. Cartilage T1rho and T2 values were quantified for subcompartments in the full-thickness, superficial, and deep layers and were compared with the matched subcompartments of control knees. The influence of concomitant meniscal tears identified using proton density-weighted imaging (PDWI) was also investigated. RESULTS: In the posterior lateral tibia, T1rho and T2 values were significantly higher in ACLR participants at 3 months and slightly decreased at 1-year compared to the control group. T1rho values in the medial compartment exhibited a significant increase at 1-year compared with those of control knees, while T2 showed no significance. In cartilage with medial meniscal tears, the T1rho values in multiple medial subcompartments were significantly higher than those in cartilage without medial meniscal tears, and this alteration was relatively detectable by T1rho. CONCLUSIONS: T1rho and T2 mapping is effective in evaluating cartilage degeneration following ACLR. T1rho may exhibit greater sensitivity for assessing the progression of early degeneration in the medial compartment after ACLR.

BACKGROUND: Clamping along the transsyndesmotic (TS) axis decreases the risk of malreduction when reducing syndesmotic diastasis. We aimed to measure the difference between the TS axis and the axis determined by the newly proposed fluoroscopic incisura tangent (IT) method. The measurements were compared to those between the TS axis and those based on the center-center (CC) and talar dome lateral (TL) methods. METHODS: We analyzed computed tomographic images of 43 normal ankles. The IT view was simulated using a digitally reconstructed radiograph, in which the anterior and posterior fibular incisura tubercles overlapped on the internally rotated anteroposterior view. The interaxis angle between the TS and the axes determined by the IT method was measured on the axial computed tomographic image corresponding to the radiographic image. The same procedure was repeated using the CC and TL methods. The measured values were compared between the three methods using a one-factor analysis of variance. Furthermore, the measurements of the anteverted and retroverted incisurae were compared for each fluoroscopic method. RESULTS: The mean interaxis angles between the TS were - 0.5 degrees, 6.3 degrees, and - 1.8 degrees for the IT, CC, and TL methods, respectively, with a significantly larger value for the CC method than for the IT and TL methods (P < .001). No significant difference was found in the interaxis angle in the anteverted (-0.1 degrees) and retroverted (-1.0 degrees) incisurae when using the IT method (P = .15). The angles in the retroverted incisurae were larger than those of the anteverted incisurae for the CC and TL methods. CONCLUSION: The fluoroscopic IT method accurately estimated the TS axis. The interaxis angles were consistent, regardless of the incisura anatomy. The fluoroscopic method can be used to clamp and fix the syndesmosis along the TS axis. LEVEL OF EVIDENCE: Ⅳ.