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Updated: May 30, 2026
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Biomechanical Testing of Murine Tendons
Published on: October 15, 2019
Mechanical assessment of two different methods of tripling hamstring tendons when using suspensory fixation
Martyn Snow1, William Cheung, Jamaluddin Mahmud
1The Royal Orthopaedic Hospital, Birmingham, UK.
Summary
Doubling or tripling hamstring tendon grafts using an Endobutton showed no significant difference in ultimate strength. However, tripled grafts experienced greater cyclic elongation, suggesting caution for clinical use.
Area of Science:
- Orthopedic surgery
- Biomechanical engineering
- Sports medicine
Background:
- Tendon graft fixation is crucial for successful anterior cruciate ligament (ACL) reconstruction.
- The use of doubled or tripled hamstring tendon grafts is common, but their biomechanical properties require further investigation.
- Endobutton fixation is a widely used method for securing tendon grafts.
Purpose of the Study:
- To compare the biomechanical behavior of doubled versus tripled hamstring tendon grafts fixed with an Endobutton.
- To evaluate suture fixation techniques and their impact on tendon properties.
Main Methods:
- Thirty bovine tendons were allocated to three groups: doubled tendon with Endobutton, tripled tendon with Ultrabraid fixation, and tripled tendon with Fibreloop fixation.
- Constructs underwent cyclic loading followed by load-to-failure testing.
- Digital image capture was used to measure displacement, strain, and stress.
Main Results:
- No statistically significant differences were found in ultimate tensile strength (UTS) or yield load among the three groups.
- The tripled tendon groups showed greater mean displacement in the third limb compared to the doubled portion (Group 2: 4.8 mm, Group 3: 1.5 mm).
- Mean stress in the third limb of tripled grafts was significantly lower than in the doubled portion.
Conclusions:
- Doubled and tripled hamstring tendon grafts exhibit similar overall mechanical properties in this biomechanical study.
- Tripled grafts demonstrated significant cyclic elongation in the third limb, raising concerns for clinical application.
- Caution is advised when tripling hamstring grafts, especially smaller ones, as it may not offer immediate or long-term biomechanical advantages and could increase failure risk.
