Biomechanical study of healing of patellar tendon after resection of the central one-third in an adult-mature rabbit model

Article type: Research Article

Authors: Maeda, Eijiro^{; ;} | Noguchi, Hitoshi^; | Tohyama, Harukazu | Yasuda, Kazunori | Hayashi, Kozaburo^;

Affiliations: Biomechanics Laboratory, Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, Osaka, Japan | Department of Sports Medicine and Joint Reconstruction Surgery, Hokkaido University School of Medicine, Sapporo, Japan

Note: [] Address for correspondence: Eijiro Maeda, Faculty of Engineering, Hokkaido University, N13 W8, Kita-ku, Sapporo, 060-8628, Japan. Tel.: +81 11 706 6427; Fax: +81 11 706 6426; E-mail: e.maeda@eng.hokudai.ac.jp

Note: [] Present affiliation: Faculty of Engineering, Hokkaido University, Sapporo, Japan.

Note: [] Present affiliation: Denso Corporation, Nagoya, Japan.

Note: [] Present affiliation: Department of Biomedical Engineering, School of Engineering, Okayama University of Science, Okayama, Japan.

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.

Keywords: Patellar tendon, mechanical properties, ageing, regenerated tissue, residual tissue, regenerative medicine

DOI: 10.3233/BME-130742

Journal: Bio-Medical Materials and Engineering, vol. 23, no. 3, pp. 173-181, 2013