Effects of gamma irradiation on the biomechanical properties of peroneus tendons.
OBJECTIVE
This study was designed to investigate the biomechanical properties of nonirradiated (NI) and irradiated (IR) peroneus tendons to determine if they would be suitable allografts, in regards to biomechanical properties, for anterior cruciate ligament reconstruction after a dose of 1.5-2.5 Mrad.


METHODS
Seven pairs of peroneus longus (PL) and ten pairs of peroneus brevis (PB) tendons were procured from human cadavers. The diameter of each allograft was measured. The left side of each allograft was IR at 1.5-2.5 Mrad, whereas the right side was kept aseptic and NI. The allografts were thawed, kept wet with saline, and attached in a single-strand fashion to custom freeze grips using liquid nitrogen. A preload of 10 N was then applied and, after it had reached steady state, the allografts were pulled at 4 cm/sec. The parameters recorded were the displacement and force.


RESULTS
The elongation at the peak load was 10.3±2.3 mm for the PB NI side and 13.5±3.3 mm for the PB IR side. The elongation at the peak load was 17.4±5.3 mm for the PL NI side and 16.3±2.0 mm for the PL IR side. For PL, the ultimate load was 2,091.6±148.7 N for NI and 2,122.8±380.0 N for IR. The ultimate load for the PB tendons was 1,485.7±209.3 N for NI and 1,318.4±296.9 N for the IR group. The ultimate stress calculations for PL were 90.3±11.3 MPa for NI and 94.8±21.0 MPa for IR. For the PB, the ultimate stress was 82.4±19.0 MPa for NI and 72.5±16.6 MPa for the IR group. The structural stiffness was 216.1±59.0 N/mm for the NI PL and 195.7±51.4 N/mm for the IR side. None of these measures were significantly different between the NI and IR groups. The structural stiffness was 232.1±45.7 N/mm for the NI PB and 161.9±74.0 N/mm for the IR side, and this was the only statistically significant difference found in this study (P=0.034).


CONCLUSIONS
Our statistical comparisons found no significant differences in terms of elongation, ultimate load, or ultimate stress between IR and NI PB and PL tendons. Only the PB structural stiffness was affected by irradiation. Thus, sterilizing allografts at 1.5-2.5 Mrad of gamma irradiation does not cause major alterations in the tendons' biomechanical properties while still providing a suitable amount of sterilization for anterior cruciate ligament reconstruction.
Department of Biological Sciences, Florida International University, Miami, FL, USA.
Christopher M
CM
Aguila
Department of Orthopaedics, Miller School of Medicine, University of Miami, Miami, FL, USA; Research Service & Geriatric Research, Education, and Clinical Center, Bruce W. Carter Veterans Affairs Medical Center, Miami, FL, USA; Interdisciplinary Stem Cell Institute, University of Miami, Miami, FL, USA; Vivex Biomedical Inc., Marietta, GA, USA.
Gaëtan J-R
GJ
Delcroix
Max Biedermann Institute for Biomechanics, Miami Beach, FL, USA.
David N
DN
Kaimrajh
Max Biedermann Institute for Biomechanics, Miami Beach, FL, USA.
Edward L
EL
Milne
Vivex Biomedical Inc., Marietta, GA, USA; Translational Research and Economic Development, Nova Southeastern University, Fort-Lauderdale, FL, USA.
H Thomas
HT
Temple
Department of Orthopaedics, Miller School of Medicine, University of Miami, Miami, FL, USA; Max Biedermann Institute for Biomechanics, Miami Beach, FL, USA.
Loren L
LL
Latta
ACL reconstruction; allograft; sterilization; tissue banking
Arthroscopy. 2010 Dec;26(12):1641-7
20875723
Am J Sports Med. 1995 Sep-Oct;23(5):643-6
8526284
Am J Sports Med. 2013 Apr;41(4):835-40
23388672
J Orthop Res. 1995 Nov;13(6):898-906
8544027
J Am Acad Orthop Surg. 2005 May-Jun;13(3):197-207
15938608
Cell Tissue Bank. 2012 Aug;13(3):387-400
22311070
Acta Orthop Traumatol Turc. 2008 Jan-Feb;42(1):38-43
18354276
Am J Sports Med. 2007 Oct;35(10):1653-8
17517908
Am J Sports Med. 1996 Mar-Apr;24(2):230-4
8775127
Vox Sang. 2003 Jan;84(1):36-44
12542732
Arthroscopy. 2013 Apr;29(4):756-65
23369445
Knee Surg Sports Traumatol Arthrosc. 2011 Nov;19(11):1955-61
21541710
J Orthop Res. 1997 Jan;15(1):111-7
9066534
Orthopedics. 2010 Apr;33(4):null
20415299
Cell Tissue Bank. 2007;8(2):81-91
16821106