Shelton TJ, Delman C, McNary S, et al. - This study was undertaken to ascertain if aging imparts a clinically significant effect on the (1) mechanism of graft failure and structural, material, and viscoelastic properties of patellar tendon allografts by assessing these properties in younger donors (≤ 30 years of age) and older donors (> 50 years of age). Researchers included a sum of 34 younger (≤ 30 years of age) and 34 older (> 50 years of age) nonirradiated, whole bone-tendon-bone allografts and prepared them for testing by isolating the central third of the patellar tendon using a double-bladed 10-mm width scalpel under a 10-N load to ensure uniformity of harvest. According to the findings, aging weakens the bone-tendon junction and reduces the ultimate tensile strength of patellar tendon allografts. Nevertheless, the displacement, strain, stiffness, elastic modulus, creep displacement or creep strain of patellar tendon allografts were not affected by aging.