Acta chirurgiae orthopaedicae
et traumatologiae Čechoslovaca

Acta Chir Orthop Traumatol Cech. 2017; 84(2):101-105 | DOI: 10.55095/achot2017/015

Structural Damage to the Hamstring Graft due to Interaction with Fixation Material and its Effect on Biomechanical Properties of ACL ReconstructionOriginal papers

J. KAUTZNER^1,*, M. DRŽÍK², M. HANDL¹, C. POVÝŠIL³, P. KOS¹, T. TRČ¹, V. HAVLAS¹

¹ Klinika dětské a dospělé ortopedie a traumatologie 2. lékařské fakulty Univerzity Karlovy a Fakultní nemocnice Motol, Praha

² International Laser Center, Bratislava

³ Ústav patologie 1. lékařské fakulty Univerzity Karlovy a Všeobecné fakultní nemocnice, Praha

PURPOSE OF THE STUDY:
Hamstring grafts are commonly used for ACL reconstruction. The purpose of our study is to determine the effects of the suspension fixation compared to graft cross-pinning transfixation, and the effect(s) of structural damage during the preparation of the graft on biomechanical properties of the graft.

MATERIAL AND METHODS:
The design of the study is a cadaveric biomechanical laboratory study. 38 fresh-frozen human hamstring specimens from 19 cadaveric donors were used. The grafts were tested for their loading properties. One half of each specimen was suspended over a 3.3mm pin, the other half was cross-pinned by a 3.3mm pin to simulate the graft cross-pinning technique. Single impact testing was performed and the failure force, elongation and acceleration/deceleration of each graft was recorded and the loading force vs. elongation of the graft specimens was calculated. Results for suspended and cross-pinned grafts were analysed using ANOVA method, comparing the grafts from each donor.

RESULTS:
The ultimate strength of a double-strand gracilis graft was 1287 ± 134 N when suspended over a pin, the strength of a cross-pinned graft was 833 ± 111 N. For double-strand semitendinosus grafts the strengths were 1883 ± 198 and 997 ± 234 N, respectively. Thus, the failure load for the cross-pinning method is only 64.7% or 52.9% for the suspension method.

DISCUSSION:
Structural damage to the graft significantly reduces the graft strength. Also, extensive suturing during preparation of the graft reduces its strength.

CONCLUSIONS:
Fixation methods that do not interfere with the graft's structure should be used to reduce the risk of graft failure.

Keywords: ACL reconstruction, hamstring graft, biomechanical testing

Published: April 1, 2017  Show citation