The treatment of large bone defects still poses a major challenge in orthopaedic and craniomaxillofacial surgery. One possible solution could be the development of personalized porous titaniumbased implants that are designed to meet all mechanical needs with a minimum amount of titanium and maximum osteopromotive properties so that it could be combined with growth factor-loaded hydrogels or cell constructs to realize advanced bone tissue engineering strategies. Such implants could prove useful for mandibular reconstruction, spinal fusion, the treatment of extended long bone defects, or to fill in gaps created on autograft harvesting. The aim of this study was to determine the mechanical properties and potential of bone formation of light weight implants generated by selective laser melting (SLM). We mainly focused on osteoconduction, as this is a key feature in bone healing and could serve as a backup for osteoinduction and cell transplantation strategies. To that end, defined implants were produced by SLM, and their surfaces were left untreated, sandblasted, or sandblasted/acid etched. In vivo bone formation with the different implants was tested throughout calvarial defects in rabbits and compared with untreated defects. Analysis by micro computed tomography (CT) and histomorphometry revealed that all generatively produced porous Ti structures were well osseointegrated into the surrounding bone. The histomorphometric analysis revealed that bone formation was significantly increased in all implanttreated groups compared with untreated defects and significantly increased in sand blasted implants compared with untreated ones. Bone bridging was significantly increased in sand blasted acid-etched scaffolds. Therefore, scaffolds manufactured by SLM should be surface treated. Bone augmentation beyond the original bone margins was only seen in implant-treated defects, indicating an osteoconductive potential of the implants that could be utilized clinically for bone augmentation purposes. Therefore, designed porous, lightweight structures have potential for bone regeneration and augmentation purposes, especially when complex and patient-specific geometries are essential. This article has been peer-reviewed and accepted for publication, but has yet to undergo copyediting and proof correction. The final published version may differ from this proof. 2 AbstractThe treatment of large bone defects still poses a major challenge in orthopaedic and cranio-maxillofacial surgery. One possible solution could be the development of personalized porous titanium-based implants designed to meet all mechanical needs with a minimum amount of titanium and maximum osteopromotive properties so that it could be combined with growth factor loaded hydrogels or cell constructs to realize advanced bone tissue engineering strategies. Such implants could prove useful for mandibular reconstruction, spinal fusion, the treatment of extended long bone defects, or to fill in gaps created upon autograft harvesting. The aim of this study was t...

This cadaveric study has shown that overall operation time including the fluoroscopy time can be shortened by using the individual template for the pedicle bore. The individual template is an alternative to the computer-assisted navigation systems with a good cost-performance ratio without excessive technical workload on the physicians or the surgical personnel. Further investigations must be conducted to validate the clinical applicability of this system.

Intraoperative acceleration measurements to quantify improvement in tremor during deep brain stimulation surgery. Medical and Biological Engineering and Computing, Springer Verlag, 2017, 55 (5) AbstractDeep brain stimulation (DBS) surgery is extensively used in the treatment of movement disorders. Nevertheless, methods to evaluate the clinical response during intraoperative stimulation tests to identify the optimal position for the implantation of the chronic DBS lead remain subjective. In this paper, we describe a new, versatile method for quantitative intraoperative evaluation of improvement in tremor with an acceleration sensor that is mounted on the patient's wrist during surgery. At each anatomical test position, the improvement in tremor compared to the initial tremor is estimated on the basis of extracted outcome measures. This method was tested on 15 tremor patients undergoing DBS surgery in two centers. Data from 359 stimulation tests were acquired. Our results suggest that accelerometric evaluation detects tremor changes more sensitively than subjective visual ratings. The effective stimulation current amplitudes identified from the quantitative data (1.1 ± 0.8 mA) are lower than those identified by visual evaluation (1.7 ± 0.8 mA) for similar improvement in tremor. Additionally, if these data had been used to choose the chronic implant position of the DBS lead, 15 of the 26 choices would have been different. These results show that our method of accelerometric evaluation can potentially improve DBS targeting.

No abstract

Metal-on-metal hip resurfacing arthroplasties represent an alternative to total hip arthroplasties for young and active patients, enabling the preservation of intact femoral bone and therefore improving the prognosis for future hip joint replacements. Follow-up studies have shown that the main reasons for early implant failure are mal-orientation of the implant stem in relation to the femoral neck axis, and notching of the femoral neck during femoral head preparation, as well as by exposed cancellous bone after implantation. A computer-assisted planning and navigation system for the implantation of femoral hip resurfacing implants has been developed which supports the surgeon during intraoperative fluoroscopy-based planning and navigation of implant positioning. This paper presents the results of a cadaver study performed to evaluate the system's functionality and accuracy.