H J Wilke1, B Jungkunz, K Wenger, L E Claes. 1. Department Unfallchirurgische Forschung und Biomechanik, Universität Ulm, Germany. wilke@sirius.medizin.uni-ulm.de
Abstract
BACKGROUND: The purpose of this study was to thoroughly evaluate the relationship of possible mechanical and environmental conditions in the testing of spinal joint segments, including ambient-temperature exposure, accumulated test cycles, angular-deformation rate, and moisture condition on the motion characteristics of joints, with the example of isolated spinal segments. METHODS: In one test, controlled loading was applied to six motion segments every 8 hours in each of the primary anatomical directions while moisture was held constant. In a second test, 18 specimens were divided equally into moisture-static, air-exposed, and slowly irrigated groups and loaded to 500 cycles. In a third test, a similar sample was tested over a range of angular-deformation rates (0.6-5.1 degrees/second). RESULTS: Range of motion (ROM) increased steadily with ambient-temperature exposure time, resulting in a 10% change at about 20 hours but was most stable in the moisture-static group over both accumulated load cycles and loading rate changes. CONCLUSIONS: The most critical factor for functional testing of spinal segments appears to be length of exposure.
BACKGROUND: The purpose of this study was to thoroughly evaluate the relationship of possible mechanical and environmental conditions in the testing of spinal joint segments, including ambient-temperature exposure, accumulated test cycles, angular-deformation rate, and moisture condition on the motion characteristics of joints, with the example of isolated spinal segments. METHODS: In one test, controlled loading was applied to six motion segments every 8 hours in each of the primary anatomical directions while moisture was held constant. In a second test, 18 specimens were divided equally into moisture-static, air-exposed, and slowly irrigated groups and loaded to 500 cycles. In a third test, a similar sample was tested over a range of angular-deformation rates (0.6-5.1 degrees/second). RESULTS: Range of motion (ROM) increased steadily with ambient-temperature exposure time, resulting in a 10% change at about 20 hours but was most stable in the moisture-static group over both accumulated load cycles and loading rate changes. CONCLUSIONS: The most critical factor for functional testing of spinal segments appears to be length of exposure.
Authors: Heiko Koller; Rene Schmidt; Michael Mayer; Wolfgang Hitzl; Juliane Zenner; Stefan Midderhoff; Stefan Middendorf; Nicolaus Graf; Nicolaus Gräf; H Resch; Hans-Joachim Wilke; Hans-Joachim Willke Journal: Eur Spine J Date: 2010-06-30 Impact factor: 3.134