title: Biomechanical study of healing of patellar tendon after resection of the central one-third in an adult-mature rabbit model.
abstract: The present study was performed to investigate effects of ageing on biomechanical properties of healing tissues of the patellar tendon (PT) after the removal of its central portion. An entire one-third defect was made in the PT of 0.5 year- (0.5 yr) and 2 year-old rabbits (2 yr). After 6 or 12 weeks, the tissue regenerated in the defect and the remaining, residual tissue was examined biomechanically and histologically. Age-related difference in the PT length was only observed in operated tendons at 6 weeks, and in the cross-sectional area such difference was observed only in unoperated, normal tendons. At 12 weeks, tensile strength and tangent modulus of regenerated tissues in 0.5 yr were significantly higher than those in 2 yr. By contrast, these properties of residual tissues in 2 yr were significantly higher than those of 0.5 yr at 6 weeks. The histology of each of regenerated and residual tissues was essentially similar between the two age groups. Accordingly, ageing exhibited adverse effects on the mechanical properties of tissues regenerated in the central third defect of the PT. This may be due to high tangent modulus of normal and residual PT tissues in aged animals, which reduces the amount of mechanical stimulation applied to regenerated tissues during healing.
authors: Biomechanics Laboratory, Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, Japan. e.maeda@eng.hokudai.ac.jp
authors: Eijiro
authors: E
authors: Maeda
authors: Hitoshi
authors: H
authors: Noguchi
authors: Harukazu
authors: H
authors: Tohyama
authors: Kazunori
authors: K
authors: Yasuda
authors: Kozaburo
authors: K
authors: Hayashi
mesh_terms: D000367:Age Factors; D000818:Animals; D001696:Biomechanical Phenomena; D005260:Female; D017847:Patellar Ligament / Q000293:injuries* / Q000473:pathology / Q000502:physiology* / Q000601:surgery; D011817:Rabbits; D012038:Regeneration; D014945:Wound Healing