A New Concept for Cervical Expansion Screws Using Shape Memory Alloy: A Feasibility Study.

Background:  In general, sufficient anchoring of screws in the bone material ensures the intended primary stability.

Methods:  Shape memory materials offer the option of using temperature-associated deformation energy in a targeted manner to compensate the special situation of osteoporotic bones or the potential lack of anchoring. An expansion screw was developed for these purposes.

Biomechanical testing of different fixation techniques for intraoperative proximal femur fractures: a technical note.

Intraoperative proximal femoral fractures (IPFF) represent a rare but challenging complication of total hip arthroplasties. They usually occur as a longitudinal split. This pilot trial aimed to compare the biomechanical primary stability of different fixation techniques for IPFF.

Influence of thread design on anchorage of pedicle screws in cancellous bone: an experimental and analytical analysis.

Threads of modern pedicle screws can vary greatly in design. It is difficult to assess which interplay of design features is particularly advantageous for screw anchorage. This study aims to increase the understanding of the anchorage behaviour between screw and cancellous bone.

Recommendations for standardised screw pull-out from polyurethane foam - The influence of density variations of the test foam and the insertion method.

Insertion and pull-out tests of synthetic test material are well established for the initial laboratory evaluation of screws. However, not all test parameters are sufficiently described. The influence of small density deviations of the test material, of tapping or of manual or machine insertion has not been fully examined.

Restricted cement augmentation in unstable geriatric midthoracic fractures treated by long-segmental posterior stabilization leads to a comparable construct stability.

The goal of this study is to compare the construct stability of long segmental dorsal stabilization in unstable midthoracic osteoporotic fractures with complete pedicle screw cement augmentation (ComPSCA) versus restricted pedicle screw cement augmentation (ResPSCA) of the most cranial and caudal pedicle screws under cyclic loading. Twelve fresh frozen human cadaveric specimens (Th4-Th10) from individuals aged 65 years and older were tested in a biomechanical cadaver study. All specimens received a DEXA scan and computer tomography (CT) scan prior to testing.

Comparison of Long Segmental Dorsal Stabilization with Complete Versus Restricted Pedicle Screw Cement Augmentation in Unstable Osteoporotic Midthoracic Vertebral Body Fractures: A Biomechanical Study.

Objective: To compare the construct stability of long-segmental dorsal stabilization in unstable midthoracic osteoporotic fracture situation with complete pedicle screw cement augmentation (ComPSCA) versus restricted pedicle screw cement augmentation (ResPSCA) of the most cranial and caudal pedicle screws.

Methods: Twelve fresh frozen human cadaveric specimens (Th 4-Th 10) aged 65 years and older were tested in a biomechanical cadaver study. All specimens received a dual-energy X-ray absorption scan and computed tomography scan before testing.

A novel parameter for the prediction of pedicle screw fixation in cancellous bone - A biomechanical study on synthetic foam.

Pedicle screw loosening is still observed in clinical practice. Therefore, the understanding of the interaction between screw and bone is evermore subject of research. However, complex relationships between screw design and anchorage are rarely examined.

Geometric adaption of biodegradable magnesium alloy scaffolds to stabilise biological myocardial grafts. Part I.

Synthetic patch materials currently in use have major limitations, such as high susceptibility to infections and lack of contractility. Biological grafts are a novel approach to overcome these limitations, but do not always offer sufficient mechanical durability in early stages after implantation. Therefore, a stabilising structure based on resorbable magnesium alloys could support the biological graft until its physiologic remodelling.