This grant evaluates how gamma irradiation affects the biomechanics of frozen goat bone-patellar tendon-bone allografts (PTBs) used to replace the anterior cruciate ligament (ACL). With growing concern that sterilly- procured allografts could transmit infectious diseases such as AIDS, tissue sterilization methods such as gamma irradiation have recently been advocated. Preliminary studies in our laboratory indicate that 2 Mrads of gamma irradiation does not significantly reduce the initial or inherent material properties of frozen goat PTB specimens. However, no study has determined whether this level of irradiations alter graft biomechanics after implantation. Two studies will be preformed to examine this question. Study 1 will be devoted to finding a single set of reproducible initial conditions for installing a PTB. Our goal is to restore the in vitro anterior-posterior translations of the intact knee. To do this we will develop methods to control the graft tension and flexion angle at surgery as well as the attachment site location and bone tunnel orientations of the graft ends. We do not seek the optimum set of conditions but only one reproducible set. Study 2 is designed to test the hypothesis that 6 months after surgery, there are no significant differences in structural mechanical or material properties between frozen and 2 Mrad irradiated frozen allografts. Paired grafts from donor animals will be either frozen or frozen and irradiated. The pair will be installed using phased surgeries. The design will block for time-order effects, potential right vs left and animal-to-animal variabilities. Power analyses will ensure adequate sample size to detect statistical differences due to the treatment variable if they exist. Tissues will be mechanically evaluated at six months after when bone healing is completed and the rate of return in mechanical properties has slowed. The results will indicate whether a commonly used irradiation method is detrimental to the mechanical integrity of an anterior cruciate ligament replacement. The study will also be the basis for examining biological changes associated with this treatment method.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR038719-02
Application #
3158744
Study Section
Orthopedics and Musculoskeletal Study Section (ORTH)
Project Start
1989-05-20
Project End
1992-04-30
Budget Start
1990-05-01
Budget End
1991-04-30
Support Year
2
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Cincinnati
Department
Type
Schools of Engineering
DUNS #
City
Cincinnati
State
OH
Country
United States
Zip Code
45221
Schwartz, Herbert E; Matava, Matthew J; Proch, Frank S et al. (2006) The effect of gamma irradiation on anterior cruciate ligament allograft biomechanical and biochemical properties in the caprine model at time zero and at 6 months after surgery. Am J Sports Med 34:1747-55
Cummings, J F; Grood, E S; Butler, D L et al. (2002) Subject variation in caprine anterior cruciate ligament reconstruction. J Orthop Res 20:1009-15
Korvick, D L; Cummings, J F; Grood, E S et al. (1996) The use of an implantable force transducer to measure patellar tendon forces in goats. J Biomech 29:557-61
Salehpour, A; Butler, D L; Proch, F S et al. (1995) Dose-dependent response of gamma irradiation on mechanical properties and related biochemical composition of goat bone-patellar tendon-bone allografts. J Orthop Res 13:898-906
Rasmussen, T J; Feder, S M; Butler, D L et al. (1994) The effects of 4 Mrad of gamma irradiation on the initial mechanical properties of bone-patellar tendon-bone grafts. Arthroscopy 10:188-97
Feder, S M; Butler, D L; Holden, J P (1993) A technique for the evaluation of the contributions of knee structures to knee mechanics in the knee that has a reconstructed anterior cruciate ligament. J Orthop Res 11:448-51
Glos, D L; Butler, D L; Grood, E S et al. (1993) In vitro evaluation of an implantable force transducer (IFT) in a patellar tendon model. J Biomech Eng 115:335-43
Xu, W S; Butler, D L; Stouffer, D C et al. (1992) Theoretical analysis of an implantable force transducer for tendon and ligament structures. J Biomech Eng 114:170-7
Oster, D M; Grood, E S; Feder, S M et al. (1992) Primary and coupled motions in the intact and the ACL-deficient knee: an in vitro study in the goat model. J Orthop Res 10:476-84
Gibbons, M J; Butler, D L; Grood, E S et al. (1991) Effects of gamma irradiation on the initial mechanical and material properties of goat bone-patellar tendon-bone allografts. J Orthop Res 9:209-18