The use of a central one-third patellar tendon as an autograft for surgical reconstruction of a c4maged cruciate ligament is common. However, recent clinical studies indicate that decreased quadriceps strength, decreased range of motion, decreased thigh circumference and patello-femoral problems can be associated with this procedure. Some of these complications may result from alterations in the structural properties of the remaining patellar tendon. The objective of this study was to examine tructural change of the remaining patellar tendon using MRI after removal of its central one-third. We evi.luated 10 patients received ACL reconstruction using autogenous central third bone-patellar tendon-bone. The mean age of the. Patient was 24 years old. The mean follow-up period was 30 months. The surgicd techn:ique was arthroscopically assisted ACL reconstruction using single incision. Only paratenon was repaired, reniaining patellar tendon defect. We checked the thickness, width, length and cross-sectional area of patellar te.ndon defect from axial MR scan. We also checked preoperative MR image of the same patient and compare, Anterior Cruciate Ligament Reconstruction* ; Anterior Cruciate Ligament* ; Autografts ; Follow-Up Studies ; Humans* ; Ligaments ; Magnetic Resonance Imaging ; Patellar Ligament* ; Range of Motion, Articular ; Tendons ; Thigh ; Young Adult