Stiffness of surrounding soft tissue of the donor site in patients with anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft

Introduction. While many studies focus on the restoration of muscle strength in the mid-term after anterior cruciate ligament reconstruction (ACLR) with bone-patellar tendon-bone (BTB) autograft, it is not known whether the mechanical properties of the donor site and surrounding soft tissue are restored. The aim of this study was to investigate the mechanical properties of the donor site patellar tendon (PT) and surrounding soft tissues after ACLR with BTB autograft. Methods. Eight patients with ACLR and 8 age-matched healthy controls were included to the study. Shear Wave Velocity (SWV) of the PT, quadriceps tendon (QT) and vastus medialis obliques (VMO) muscle were performed using an ultrasonography device with linear probe. In addition, the quadriceps femoris (QF) strength was measured with isokinetic dynamometer at 60°/sec angular velocity. Results. There were no differences in the SWV of the PT and VMO muscle between the two groups (p > 0.05). The SWV of the QT was significantly lower in patients with ACLR compared to healthy controls (p = 0.02). There was significantly reduced QF strength on the operated side in patients with ACLR (p = 0.04). Conclusions. The mechanical properties of the PT and VMO are restored in the mid-term after ACLR. However, there may be strength deficit on the donor site QF even after 16 months from the surgery.