Proximal humeral fractures: how stiff should an implant be?

Abstract

The high initial stiffness of rigid implants led to an early loosening and failure of the implant-bone interface under cyclic loading. Implants with low stiffness and elastic characteristics, however, appear to minimize the peak stresses at the bone-implant interface, making them particularly suitable for fracture fixation in osteoporotic bone.

The clinical benefit of medial support screws in locking plating of proximal humerus fractures: a prospective randomized study

“…Moreover, anatomical plate design matches the configuration of the proximal humerus and allows multidirectional locking capability of the plate constructs, which can avoid screw back-out and loosening. The fixed-angle devices of the locking plate have been proven to increase pull-out strength of the screws and have exhibited favourable results with comparison to the traditional plate, which may also improve fixation in osteoporotic bone [13,16,17]. Siffri et al investigated, in a cadaveric proximal humerus fracture-fixation model, that locking plates exhibited a greater torsional loading than blade plates (P= 0.036) [13].…”

A Mechanical Comparison of the Locking Compression Plate (LCP) and the Low Contact-Dynamic Compression Plate (DCP) in an Osteoporotic Bone Model

“…This method has been recommended by the authors in a number of previous mechanical studies. [6][7][8][9][10] Initially quasi-static testing was carried out on all specimens using an Instron 4507 universal testing machine. The specimens were first tested in compression to a maximum load of 450 N. The compression force was applied along the central axis of the bone specimen.…”

Winkelstabile Plattenosteosynthese proximaler Humerusfrakturen

“…Eine besondere Herausforderung an die Implantate stellt die unter Berücksichti-gung der Inzidenz häufig notwendige Verankerung im osteroporotischen Knochen dar [24]. …”