@article{marcellin-little_cansizoglu_harrysson_roe_2010, title={In vitro evaluation of a low-modulus mesh canine prosthetic hip stem}, volume={71}, ISSN={["1943-5681"]}, DOI={10.2460/ajvr.71.9.1089}, abstractNote={Abstract Objective —To compare an electron beam melting-processed (EBMP) low-modulus titanium alloy mesh stem with a commercial cobalt-chromium (CC) stem in a canine cadaver model. Sample Population —9 pairs of cadaver femora. Procedures —EBMP stems of 3 sizes were placed in randomly chosen sides of femora (left or right) and CC stems in opposite sides. Stem impaction distances were recorded. Five strain gauges were attached to the femoral surface to record transverse tensile (hoop) strains in the femur during axial loading. Constructs were axially loaded 4 times to 800 N and 4 times to 1,600 N in a materials testing machine. Axial stiffness of constructs and bone surface strains were compared between EBMP and CC constructs. Results —Stems were impacted without creating femoral fissures or fractures. Stem impaction distances were larger for EBMP stems than for CC stems. Mean axial stiffness of EBMP constructs was lower than mean axial stiffness of CC constructs. Subsidence did not differ between groups. Bone strains varied among strain gauge positions and were largest at the distal aspect of the stems. At a load of 1,600 N, bones strains were higher in CC constructs than in EBMP constructs for 2 of 4 medial strain gauges. Conclusions and Clinical Relevance —EBMP stems were successfully impacted and stable and led to a focal decrease in bone strain; this may represent an acceptable option for conventional or custom joint replacement. ( Am J Vet Res 2010;71:1089–1095) Although cemented hip stems have been used successfully as part of total hip replacements in humans, their success rate has been reportedly lower in younger patients than in older patients. 1 The longterm success of hip stems is affected by aseptic implant loosening, implant wear, and stress-mediated bone resorption (stress shielding). 2 Cementless hip stems were originally developed in part because polymethylmethacrylate bone cement was considered to be a contributing factor to aseptic loosening of cemented hip stems. 3 A portion of a cementless stem is textured or coated with porous surfaces for bone ongrowth and ingrowth. 4,5 Stem stability relies on initial press fit and long-term bone ingrowth into the porous portions of the stems. Cementless stems are large and have a high}, number={9}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Marcellin-Little, Denis J. and Cansizoglu, Omer and Harrysson, Ola L. A. and Roe, Simon C.}, year={2010}, month={Sep}, pages={1089–1095} }
 @article{cansizoglu_harrysson_west_cormier_mahale_2008, title={Applications of structural optimization in direct metal fabrication}, volume={14}, ISSN={["1355-2546"]}, DOI={10.1108/13552540810862082}, abstractNote={Purpose – Optimization techniques can be used to design geometrically complex components with a wide variety of optimization criteria. However, such components have been very difficult and costly to produce. Layered fabrication technologies such as electron beam melting (EBM) open up new possibilities though. This paper seeks to investigate the integration of structural optimization and direct metal fabrication process.Design/methodology/approach – Mesh structures were designed, and optimization problems were defined to improve structural performance. Finite element analysis code in conjunction with nonlinear optimization routines were used in MATLAB. Element data were extracted from an STL‐file, and output structures from the optimization routine were manufactured using an EBM machine. Original and optimized structures were tested and compared.Findings – There were discrepancies between the performance of the theoretical structures and the physical EBM structures due to the layered fabrication approach. ...}, number={2}, journal={RAPID PROTOTYPING JOURNAL}, author={Cansizoglu, Omer and Harrysson, Ola L. A. and West, Harvey A., II and Cormier, Denis R. and Mahale, Tushar}, year={2008}, pages={114–122} }
 @article{harrysson_cansizoglu_marcellin-little_cormier_west_2008, title={Direct metal fabrication of titanium implants with tailored materials and mechanical properties using electron beam melting technology}, volume={28}, ISSN={["0928-4931"]}, DOI={10.1016/j.msec.2007.04.022}, abstractNote={The design of custom or tailored implant components has been the subject of research and development for decades. However, the economic feasibility of fabricating such components has proven to be a challenge. New direct metal fabrication technologies such as Electron Beam Melting (EBM) have opened up new possibilities. This paper discusses the design and fabrication of titanium implant components having tailored mechanical properties that mimic the stiffness of bone to reduce stress shielding and bone remodeling. Finite Element Analysis was used to design the tailored structures, and results were verified using mechanical testing.}, number={3}, journal={MATERIALS SCIENCE & ENGINEERING C-BIOMIMETIC AND SUPRAMOLECULAR SYSTEMS}, author={Harrysson, Ola L. A. and CansiZoglu, Omer and Marcellin-Little, Denis J. and Cormier, Denis R. and West, Harvey A., II}, year={2008}, month={Apr}, pages={366–373} }
 @article{marcellin-little_harrysson_cansizoglu_2008, title={In vitro evaluation of a custom cutting jig and custom plate for canine tibial plateau leveling}, volume={69}, ISSN={["1943-5681"]}, DOI={10.2460/ajvr.69.7.961}, abstractNote={To design and manufacture custom titanium bone plates and a custom cutting and drill guide by use of free-form fabrication methods and to compare variables and mechanical properties of 2 canine tibial plateau leveling methods with each other and with historical control values.10 canine tibial replicas created by rapid prototyping methods.Application time, accuracy of correction of the tibial plateau slope (TPS), presence and magnitude of rotational and angular deformation, and replica axial stiffness for 2 chevron wedge osteotomy (CWO) methods were assessed. One involved use of freehand CWO (FHCWO) and screw hole drilling, whereas the other used jig-guided CWO (JGCWO) and screw hole drilling.Replicas used for FHCWO and JGCWO methods had similar stiffness. Although JGCWO and FHCWO did not weaken the replicas, mean axial stiffness of replicas after JGCWO was higher than after FHCWO. The JGCWO method was faster than the FHCWO method. Mean +/- SD TPS after osteotomy was lower for FHCWO (4.4 +/- 1.1 degrees ) than for JGCWO (9.5 +/- 0.4 degrees ), and JGCWO was more accurate (target TPS, 8.9 degrees ). Slight varus was evident after FHCWO but not after JGCWO. Mean postoperative rotation after JGCWO and FHCWO did not differ from the target value or between methods.The JGCWO method was more accurate and more rapid and resulted in more stability than the FHCWO method. Use of custom drill guides could enhance the speed, accuracy, and stability of corrective osteotomies in dogs.}, number={7}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Marcellin-Little, Denis J. and Harrysson, Ola L. A. and Cansizoglu, Omer}, year={2008}, month={Jul}, pages={961–966} }
 @article{cansizoglu_harrysson_cormier_west_mahale_2008, title={Properties of Ti-6Al-4V non-stochastic lattice structures fabricated via electron beam melting}, volume={492}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2008.04.002}, abstractNote={This paper addresses foams which are known as non-stochastic foams, lattice structures, or repeating open cell structure foams. The paper reports on preliminary research involving the design and fabrication of non-stochastic Ti–6Al–4V alloy structures using the electron beam melting (EBM) process. Non-stochastic structures of different cell sizes and densities were investigated. The structures were tested in compression and bending, and the results were compared to results from finite element analysis simulations. It was shown that the build angle and the build orientation affect the properties of the lattice structures. The average compressive strength of the lattice structures with a 10% relative density was 10 MPa, the flexural modulus was 200 MPa and the strength to density ration was 17. All the specimens were fabricated on the EBM A2 machine using a melt speed of 180 mm/s and a beam current of 2 mA. Future applications and FEA modeling were discussed in the paper.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Cansizoglu, O. and Harrysson, O. and Cormier, D. and West, H. and Mahale, T.}, year={2008}, month={Sep}, pages={468–474} }