Quadriceps tendon thickness varies along the harvestable length: A magnetic resonance imaging morphometric study

Objectives: Graft thickness is important for avoiding failure in anterior cruciate ligament reconstruction surgery. Although the quadriceps tendon (QT) is a commonly used graft, its morphology along its length has been studied less extensively. Unlike prior studies focusing on single-point measurements, this study evaluated sagittal thickness variation across the full harvestable segment to characterize changes along the portion to be harvested. Methods: In this retrospective magnetic resonance imaging (MRI)-based morphometric study, sagittal images of 143 patients aged 18–75 years without patellofemoral pathology were evaluated. QT sagittal thickness was measured at 1, 4, and 7 cm proximal to the patellar insertion. Measurements were compared with previously reported MRI-based graft adequacy thresholds (8 mm, 6.7 mm, 6.3 mm). Associations with age, sex, and thickness patterns were assessed. Results: Mean QT sagittal thickness was 7.86 ± 1.02 mm at 1 cm, 7.33 ± 1.03 mm at 4 cm, and 6.64 ± 1.11 mm at 7 cm proximal to the patellar insertion, demonstrating progressive proximal thinning. Two distinct thickness patterns were identified: A distal-dominant pattern, observed in 81 patients (56.6%), and a mid-segment dominant pattern, observed in 62 patients (43.4%). A substantial proportion of measurements fell below previously reported MRI-based graft adequacy thresholds, particularly at the proximal measurement level. Conclusion: QT thickness is not uniform along its length and decreases proximally. Therefore, single-level assessment may not adequately reflect tendon morphology across the harvestable segment.