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Prophylactic treatment is advised for metastatic bone disease patients with a high risk for fracture. Femoroplasty provides a minimally invasive procedure to stabilize the femur by injecting bone cement into the lesion. However, uncertainty remains whether it provides sufficient mechanical strength to the weight-bearing femur. The goal of this study was to quantify the improvement in bone stiffness, failure load and energy to failure due to cement augmentation of metastatic lesions at varying locations in the proximal femur. Eight pairs of human cadaveric femurs were mechanically tested until failure in a single-leg stance configuration. In each pair, an identical defect was milled in the left and right femur using a programmable milling machine to simulate an osteolytic lesion. The location of the defects varied amongst the eight pairs. One femur of each pair was augmented with polymethylmethacrylate, while the contralateral femur was left untreated. Digital image correlation was applied to measure strains on the bone surface during mechanical testing. Only femurs with a critical lesion showed an improvement in failure load and energy to failure due to augmentation. In these femurs, bone strength improved with 28% (±17%) on average and energy to failure with 58% (±41%), while stiffness did not show a significant improvement. The strain measurements from digital image correlation showed that cement augmentation reinforced the lesion, resulting in reduced strain magnitudes in the bone tissue adjacent to the lesion. The results indicate that femoroplasty may be an effective treatment to prevent fractures in several metastatic bone disease patients. However, the large scatter in the data clarifies the need for developing strategies to identify those patients who will benefit the most from the procedure. ispartof: Journal Of The Mechanical Behavior Of Biomedical Materials vol:104 ispartof: location:Netherlands status: published

In the last decade, various hybrid manufacturing processes and machining platforms have been developed, resulting in higher productivity and more efficient machining of difficult to cut materials. The broad domain of hybrid manufacturing includes on the one hand the combination of simultaneous acting processes (hybrid processes) and on the other hand sequential processes implemented on one machining platform having a significant influence on productivity. This paper gives an overview of a specific class of hybrid manufacturing processes and systems based on a combination of Mechanical and Electro Physical–Chemical processes. In this overview, the paper refers to previous review work performed within CIRP and gives in addition new and further developments in this domain.

The production of hardened precision parts is conventionally done in 3 steps. Rough machining of a workpiece in soft stage is followed by a hardening step, usually a batch process, and finalized by a hard machining finishing step. To omit the inevitable time delay and loss of accuracy because of part re-clamping, these steps should be incorporated within one flexible machining center. This paper describes the development of this machining center which allowsmachining and laser hardening in one setup, followed by a proof of concept for hardening C45 steel on this setup.