PUB - Publikationen an der Universität Bielefeld

The reamer-irrigator-aspirator (RIA) technique allows to collect large bone graft amounts without the drawbacks of iliac crest harvesting. Nevertheless, clinicalcases withoccurrence offemur fractures have been reported. Therefore, this study aimed to systematically investigate the three-dimensional geometry of the reamed bone as a function of the reaming diameter and its influence on the associated potential fracture pattern. Forty-five intactfresh-frozen human cadaveric femora underwent computed tomography (CT). They were randomized to three groups (n=15) for reaming at a diameter of either 1.5mm (Group 1), 2.5mm (Group 2) or 4.0mm (Group 3) larger than their isthmus using RIA. Reaming was followed by a second CT scan, biomechanical testing until failure and a third CT scan. All CT scans of each femur were aligned via rigid registration, and fracture lines were visualized. Subsequently, a decrease in wall thickness, cross-sectional area, and harvestedbone volume have been evaluated. The total volume of thebone graft was significantly higher for Group 3 (7.8±2.9ml) compared to Group 1 (2.9±1.1ml) and Group2 (3.0±1.1ml). The maximal relative decrease of the wall thickness was located medially (72.7%) in the third (61.4%), fourth (18.2%) and second (9.1%) eighth for all groups. As the diameter of the reaming increased, an overlap of the fracture line with the maximal relative decrease in wall thickness and a maximal average relative decrease of the cross-sectional area became more frequent. This suggests that a reaming-associated fracture is most likely to occur in this region. © 2021. The Author(s).