title: Design and evaluation of a cryogenic soft tissue fixation device -- load tolerances and thermal aspects.
abstract: Mechanical studies of soft connective tissues often encounter methodological difficulties, particularly in the secure fixation of the tissues. A simple, inexpensive technique which allowed stable cryofixation of soft tissues in uniaxial loading machines was developed. The cryogenic fixation device was evaluated in terms of its fixation strength and the temperature gradients within the tested tissues. Human patellar ligaments and quadriceps tendons were tested successfully to an average failure load of 2219N (S.D. 448N) with mid-substance failures occurring in 90% of the specimens. The temperature gradients within porcine flexor and extensor tendons were determined and found to exhibit a typical diffusion profile. The fixation quality was dependent upon the initial block temperature and the desired testing time. In summary, the cryofixation device presented here is an effective tool for soft tissue fixation but the effect of this type of fixation on internal tissue temperatures and possible testing times must be acknowledged.
authors.affiliation: M.E. Müller Institute for Biomechanics, University of Bern, Murtenstrasse 35, P.O. Box 30, CH-3010 Bern, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Rincón
authors.forename: L
authors.initials: L
authors.lastname: Schatzmann
authors.forename: P
authors.initials: P
authors.lastname: Brunner
authors.forename: H U
authors.initials: HU
authors.lastname: Stäubli
authors.forename: S J
authors.initials: SJ
authors.lastname: Ferguson
authors.forename: T R
authors.initials: TR
authors.lastname: Oxland
authors.forename: L P
authors.initials: LP
authors.lastname: Nolte
mesh_terms: D000328:Adult; D000818:Animals; D001696:Biomechanical Phenomena; D015925:Cryopreservation / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design / Q000295:instrumentation / Q000592:standards*; D006801:Humans; D017847:Patellar Ligament / Q000502:physiology; D013552:Swine; D013696:Temperature; D013710:Tendons / Q000502:physiology; D013718:Tensile Strength; D016474:Weight-Bearing