title: Biomechanical and tissue handling property comparison of decellularized and cryopreserved tibialis anterior tendons following extreme incubation and rehydration.
abstract: Little is known regarding the biomechanical profiles and tissue handling properties of decellularized and cryopreserved human tibialis anterior tendons prepared as allografts for ACL reconstruction. This study compared allografts prepared using two extremes of the same cryoprotectant incubation and rehydration technique with a standardly prepared control group. Porcine tibiae with similar apparent BMD were randomly divided into three groups of ten specimens. Paired tendons were randomly divided into two experimental groups: Group 1 = 8 h incubation/15 min rehydration; Group 2 = 2 h incubation/1 h rehydration. Group 3 (control) consisted of ten standardly prepared tendons with 20 min rehydration. Tissue handling properties were graded during allograft preparation using a modified visual analog scale. Similar diameter allografts were fixed in matched diameter extraction drilled tibial tunnels with 35 mm long, 1 mm > tunnel diameter bioabsorbable interference screws. Potted constructs were mounted in a servo hydraulic device, pretensioned between 10-50 N at 0.1 Hz (10 cycles), and isometric pretensioned at 50 N for 1 min, prior to 500 submaximal loading cycles (50-250 N) at 0.5 Hz, and load to failure testing (20 mm/min). Constructs prepared under extreme conditions generally displayed comparable biomechanical properties to the control condition. Group 1 (8 h incubation/15 min rehydration)(-34 +/- 35 ms) and Group 2 (2 h incubation/1 h rehydration) (-22 +/- 38 ms) displayed smaller mean displacement-load peak phase timing differences over the initial ten cycles compared to Group 3 (control)(-42 +/- 49 ms), P = 0.004, suggesting greater relative construct stiffness. Group 1 (8 h incubation/15 min rehydration) (234.9 +/- 34 N/mm) and Group 2 (2 h incubation/1 h rehydration)(231.3 +/- 43 N/mm) displayed lower construct stiffness during load to failure testing than Group 3 (control)(284.5 +/- 25.2 N/mm), P = 0.003. Group 1 (8 h incubation/15 min rehydration) differed from Group 2 (2 h incubation/1 h rehydration) and Group 3 (control) for perceived tensile stiffness (2.4 +/- 2.0 vs. 7.0 +/- 0.5 and 7.9 +/- 0.3, respectively), compressive resilience (1.7 +/- 0.8 vs. 5.9 +/- 1.0 and 7.8 +/- 0.4, respectively), handling ease (2.8 +/- 1.0 vs. 6.5 +/- 0.5 and 7.0 +/- 0.7, respectively), color (2.6 +/- 0.8 vs. 4.7 +/- 0.7 and 5.1 +/- 0.3, respectively) and texture (4.0 +/- 0.8 vs. 6.2 +/- 0.8 and 6.8 +/- 0.8, respectively) (P < 0.0001). Group 2 (2 h incubation/1 h rehydration)(6.0 +/- 0.7 and 5.9 +/- 1.0, respectively) also differed from Group 3 (control)(6.8 +/- 0.8 and 7.8 +/- 0.4, respectively) for general "feel" and compressive resilience (P < 0.0001). Tensile stiffness and compressive resilience displayed moderate and weak relationships, respectively with displacement during submaximal cyclic loading (r2 = 0.78 and 0.58, respectively), stiffness (r2 = 0.33 and 0.44, respectively) and load at failure (r2 = 0.59 and 0.37, respectively) for Group 3 (control), but not for experimental Group 1 (8 h incubation/15 min rehydration) or Group 2 (2 h incubation/1 h rehydration). Knee surgeons should be aware that soft tissue tendon decellularization and cryopreservation may change the biomechanical stiffness, tissue handling properties, and relationships between these variables compared to standardly prepared allograft tissue.
authors.affiliation: Division of Sports Medicine, Department of Orthopaedic Surgery, University of Louisville, 210 East Gray St., Suite 1003, Louisville, KY 40202, USA. john.nyland@louisville.edu
authors.forename: J
authors.initials: J
authors.lastname: Nyland
authors.forename: N
authors.initials: N
authors.lastname: Larsen
authors.forename: R
authors.initials: R
authors.lastname: Burden
authors.forename: H
authors.initials: H
authors.lastname: Chang
authors.forename: D N M
authors.initials: DN
authors.lastname: Caborn
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015925:Cryopreservation / Q000379:methods*; D006801:Humans; D007719:Knee Joint; D015532:Rehydration Solutions; D013314:Stress, Mechanical; D034421:Sus scrofa; D013710:Tendons / Q000166:cytology / Q000502:physiology* / Q000637:transplantation*; D013718:Tensile Strength; D014184:Transplantation, Homologous
chemical_list: D015532:Rehydration Solutions
references.citation: Hand. 1982 Jun;14(2):111-9
references.pmid: 6288520
references.citation: J South Orthop Assoc. 1998 Spring;7(1):13-8
references.pmid: 9570727
references.citation: Am J Sports Med. 1990 Sep-Oct;18(5):457-65
references.pmid: 2252084
references.citation: Arthroscopy. 2005 Oct;21(10):1273
references.pmid: 16226664
references.citation: Arthroscopy. 2003 Dec;19(10):1091-6
references.pmid: 14673451
references.citation: J Biomed Mater Res A. 2005 Dec 15;75(4):841-54
references.pmid: 16123978
references.citation: J Orthop Res. 2006 May;24(5):1011-8
references.pmid: 16514624
references.citation: J Bone Joint Surg Br. 1984 Nov;66(5):672-81
references.pmid: 6501359
references.citation: Am J Sports Med. 1990 Jan-Feb;18(1):1-10; discussion 10-1
references.pmid: 2301680
references.citation: Am J Sports Med. 1991 Jan-Feb;19(1):35-41
references.pmid: 2008928
references.citation: Arthroscopy. 2002 Jul-Aug;18(6):589-97
references.pmid: 12098119
references.citation: Calcif Tissue Int. 1994 Jul;55(1):59-67
references.pmid: 7922791
references.citation: MedGenMed. 2004 Oct 19;6(4):23
references.pmid: 15775850
references.citation: Arthroscopy. 2003 Apr;19(4):424-5
references.pmid: 14569971
references.citation: Arthroscopy. 2002 Feb;18(2):163-70
references.pmid: 11830810
references.citation: Am J Sports Med. 1991 Mar-Apr;19(2):112-8
references.pmid: 2039061
references.citation: J Bone Joint Surg Br. 1988 Aug;70(4):556-60
references.pmid: 3403597
references.citation: J Bone Joint Surg Am. 1986 Mar;68(3):376-85
references.pmid: 3949832
references.citation: Knee Surg Sports Traumatol Arthrosc. 2007 Jul;15(7):851-6
references.pmid: 17437083
references.citation: Arthroscopy. 2000 Nov;16(8):E20
references.pmid: 11078553
references.citation: Am J Sports Med. 2006 Nov;34(11):1747-55
references.pmid: 16735581
references.citation: Calcif Tissue Int. 1999 Apr;64(4):357-63
references.pmid: 10089231
references.citation: J Biomater Appl. 2009 Nov;24(4):343-52
references.pmid: 18987017
references.citation: Med Sci Sports Exerc. 2006 Dec;38(12):2058-67
references.pmid: 17146311
references.citation: Am J Sports Med. 1988 Mar-Apr;16(2):101-5
references.pmid: 3377093
references.citation: Bone. 1995 Sep;17(3):197-203
references.pmid: 8541131
references.citation: Am J Sports Med. 2007 Apr;35(4):612-6
references.pmid: 17293462
references.citation: Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2003 Sep;17(5):370-3
references.pmid: 14551932
references.citation: J Bone Joint Surg Am. 2005 Aug;87(8):1673-9
references.pmid: 16085604
references.citation: Am J Sports Med. 2004 Apr-May;32(3):765-71
references.pmid: 15090395
references.citation: J Knee Surg. 2006 Jul;19(3):207-14
references.pmid: 16893161
references.citation: Chin J Traumatol. 2006 Apr;9(2):72-6
references.pmid: 16533430
references.citation: Arthroscopy. 2005 Jul;21(7):774-85
references.pmid: 16012489
references.citation: Arthroscopy. 2005 Jul;21(7):786-90
references.pmid: 16012490
references.citation: Arthroscopy. 2007 May;23(5):469-75
references.pmid: 17478276
references.citation: Arthroscopy. 2007 Nov;23(11):1210-7
references.pmid: 17986409
references.citation: Am J Sports Med. 2003 May-Jun;31(3):474-81
references.pmid: 12750147
references.citation: J Bone Joint Surg Br. 1963 Feb;45-B:182-95
references.pmid: 14040476