Effects of heparin with local injection on the biomechanical properties of Achilles tendon system in rabbits
- VernacularTitle:局部注射肝素钠免跟腱系统生物力学性质的变化
- Author:
Bo LIU
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2008;12(50):9982-9985
- CountryChina
- Language:Chinese
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Abstract:
BACKGROUND: Achilles peritendinitis can change characteristics of mechanical and viscoelastic properties in Achilles tendon, especially the biomechanical properties of Achilles tendon after heparin local injection. OBJECTIVE: To examine the changes of mechanical and viscoelastic properties in Achilles tendon of overuse injuries and the effects of heparin on the mechanical and viscoelastic properties in Achilles tendon. DESIGN, TIME AND SETTIMG: Control animal specimen study was performed at the Biomechanical Laboratory of Sichuan Province Orthopaedic Hospital between March and December 2005. MATERIALS: Fifty Achilles tendon samples from Japanese White rabbits weighing (4.10±0.23) kg were used in this study. METHODS: Rabbits were divided into a control group (n=20), an exercise group (n=12) and a heparin treatment group (n= 18) at random. The rabbits were exercised for 3 weeks, simultaneously the heparin solution were injected into the peritendineum around the insertion of Achilles-calcaneus from the 4th week to the 6th week, twice a week. Then the cyclic stretching on the Achilles tendon was performed for 25 cycles and the tendon was stretched to the constant load to determine the stress relaxation vs, time. Finally the preparation was loaded to failure to measure the biomechanical characteristics of the tendon. MAIN OUTCOME MEARES: The cross-sectional area of the tendon, the cyclic creep lengths versus time, hysteresis loop, the stress relaxation versus time, the strength properties and the stress versus strain characteristics. RESULTS: The normalized area of hysteresis from exercise and heparin groups were significantly reduced in the most cycles, and the stress relaxation reduced more quickly in the exercise and heparin groups. The mean values for yield load and failure energy, yield energy, and yield stress, strain energies from the exercised preparations were higher than those of the controls. All of the mechanical properties from the heparin treated preparations were improved significantly. CONCLUSION: The results showed that the tensile strength and viscoelastic properties of tendon were improved by the management of heparin. It is indicated that the local injections of heparin at the location of peritendineum and tendon-bone insertions are beneficial to viscoelastic and tensile behaviors of the Achilles tendon system.
