Variations in graft maturity between quadriceps tendon and semitendinosus tendon at 6 months after anterior cruciate ligament reconstruction: A quantitative assessment using UTE-T2* mapping.

Abstract

The semitendinosus (ST) tendon is commonly used as a graft in anterior cruciate ligament (ACL) reconstruction. However, there is growing interest in the quadriceps tendon (QT). The reconstructed ACL undergoes a remodeling process, and its tissue quality is an important factor in determining when to return to sports activities. It remains unclear whether there are differences in tissue quality between QT and ST grafts at the same postoperative stage. UTE-T2* mapping has gained attention as a method for quantitatively evaluating the organization of the reconstructed ACL. This study aimed to reveal differences in tissue quality and collagen organization between QT and ST grafts at 6 months after ACL reconstruction using UTE-T2* mapping. In this retrospective comparative study, twenty patients who had undergone ACL reconstruction using the QT and ST were included. UTE-T2* mapping was performed 6 months after surgery. T2* value was measured at intraarticular, femoral tunnel and tibial tunnel site. Each value were compared between the two groups (The Mann-Whitney U test). In the QT group, the T2* values were 11.8 ± 1.3 ms (intra-articular), 7.8 ± 1.6 ms (tibial), and 8.9 ± 1.5 ms (femoral). In the ST group, the corresponding UTE-T2* values were 11.1 ± 2.2 ms, 7.5 ± 1.9 ms, and 10.8 ± 1.6 ms, respectively. Notably, a significant difference was observed between the two groups in the femoral site (P = 0.026). QT grafts were more mature than ST grafts within the femoral tunnel six months after ACL reconstruction.