Quantitative assessment of graft maturation after anterior cruciate ligament reconstruction using quadriceps tendon: Insights from ultra short echo time T2∗ mapping.

Abstract

Recently, the quadriceps tendon (QT) has gained attention as a graft material for anterior cruciate ligament (ACL) reconstruction. However, no study has yet evaluated the maturation process of the reconstructed ACL using QT grafts. Magnetic resonance imaging (MRI)-Ultra Short Echo time (UTE) T2∗ mapping is a precise technique for quantifying tissue states in tendons and ligaments. This study aimed to prospectively observe trends in UTE-T2∗ values for the intra-articular and intra-osseous regions of the reconstructed ACL from 6 to 12 months following ACL reconstruction using MRI-UTE-T2∗ mapping and to assess graft maturation of the reconstructed ACL with QT grafts. This study enrolled 10 patients (five males and five females). For each patient, UTE-T2∗ values were measured at 6, 9, and 12 months postoperatively. A two-way mixed ANOVA was performed with time (6, 9, and 12 months) as a within-subjects factor and location (intra-articular, tibial intra-osseous, and femoral intra-osseous) as a between-subjects factor. A significant main effect of time was observed (F (2,54) = 38.162, p < 0.001), with UTE-T2∗ values decreasing as postoperative time progressed. Additionally, a significant main effect of measurement location was identified (F (2,27) = 95.853, p < 0.001), with intra-articular UTE-T2∗ values being significantly higher than those in the tibial and femoral intra-osseous regions (p < 0.001). Quantitative assessment using MRI-UTE-T2∗ mapping following ACL reconstruction with QT grafts demonstrated that graft maturation progressed more rapidly in the intra-osseous region compared to the intra-articular region.