Osseointegrability of 3D-printed porous titanium alloy implant on tibial shaft bone defect in rabbit model.

Previous studies have demonstrated the ability of osseointegration of porous titanium implants in cancellous bone. Our study was designed to (i) investigate the ability of bone ingrowth into 3D-printed porous titanium alloy implant on the cortical bone of rabbits using CT-scan and histology, and (ii) to identify the consistency of the radiology information between clinical Cone Beam Computed Tomography (CBCT) and Micro Computed Tomography (µCT) in the evaluation of bone ingrowth. The porous titanium alloy implants were 3D-printed employing the Electron Beam Melting (EBM) technology with an intended pore size of 600 µm and porosity of approximately 50 percent. Each implant was inserted into tibial diaphysis in one rabbit and its pores were classified as contacting bone or non-contacting bone. Depending on the time of explantation, the rabbits were divided into two groups: group 1 consisting of 6 rabbits between 13 and 20 weeks and group 2 consisting of 6 rabbits between 26 and 32 weeks. Tissue ingrowth into the non-bone contacting pores were evaluated by CBCT and histology. µCT was used to further investigate the bone ingrowth into four implants (two from each group were randomly chosen). The CBCT detected the present of tissue with bone-like density in both bone-contacting pores and non-bone-contacting pores of all implants. The µCT analysis also supported this result. All the bone-like tissues were then histologically confirmed to be mature bone. The analysis of CBCT data to assess bone ingrowth in porous implants had the sensitivity, specificity, positive and negative predictive values of 85, 84, 93 and 70 percent, respectively, when considering µCT assessment as the gold standard. Fully porous titanium alloy implant has great potential to reconstruct diaphyseal bone defect due to its good ability of osseointegration. CBCT is a promising method for evaluation of bone ingrowth into porous implants.

A novel web-support intervention to promote recovery following Anterior Cruciate Ligament reconstruction: A pilot randomised controlled trial.

BACKGROUND: Self-efficacy is positively associated with adherence behaviours and rehabilitation outcomes following Anterior Cruciate Ligament (ACL) reconstruction. An internet resource can be an effective way to provide information, goal setting, patient monitoring and hence support overall self-management. PURPOSE: This study examined the feasibility of a three month 'internet-based intervention' (mobile-oriented site) to enhance recovery for patients following ACL reconstruction. The potential effect of the internet-based intervention on knee pain, function, self-efficacy and fear of pain were also assessed. METHOD: This was a pilot randomised controlled trial (RCT) with pre and post intervention design (assessments at one week and three months following ACL reconstruction) comparing: (1) a control group and (2) an intervention group (internet-based intervention). A set of qualitative and quantitative assessments were included to evaluate potential improvements in self-efficacy, pain and function and perception of the internet intervention. RESULTS AND CONCLUSION: Seventeen participants were available for analysis (n = 10 intervention and n = 7 control group). Participants reported the internet-based intervention to be a useful tool for information, reminder and reinforcement for performing their exercise rehabilitation with 30.3% (±35.3%) adherence to the internet-based intervention. No differences were observed between the groups over time on the outcome questionnaires (p > 0.05). Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12616001379404.

Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology.

Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece.

Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part II. Defects.

Synchrotron X-ray tomography (SXRT) has been applied to the study of defects within three-dimensional printed titanium parts. These parts were made using the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V) as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. The samples represent a selection of complex shapes with a variety of internal morphologies. Inspection via SXRT has revealed a number of defects which may not otherwise have been seen. The location and nature of such defects combined with detailed knowledge of the process conditions can contribute to understanding the interplay between design and manufacturing strategy. This fundamental understanding may subsequently be incorporated into process modelling, prediction of properties and the development of robust methodologies for the production of defect-free parts.