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Recent developments in the medical field of additive manufacturing (AM) have allowed the creation of patient-specific porous titanium implants for use in the medical field. With correct pore size such scaffolds are able to be integrated into surrounding bone.Two dogs were presented with atrophic non-union of the proximal ulna involving the elbow joint due to previous orthopaedic procedures with severe complications that led to segmental bone defects that were not expected to heal without a secondary intervention. Computed tomography (CT) was performed and porous scaffolds and saw guides were designed in silico and printed by AM. Osteotomies in adjacent healthy bone were guided by patient-specific three-dimensional (3D)-printed nylon saw guides allowing a perfect fit for the 3D-printed implant. In one case the scaffold was filled with bone morphogenic protein and held in place by two plates. In the other case the scaffold was filled with cancellous bone graft and held in place by a titanium plate that was part of the scaffold design. Both cases regained function and weight-bearing without lameness. Osseointegration of the implant was shown in both cases on follow-up CT and radiographs and macroscopically evident in the pores of the 3D implant after plate removal. One dog was euthanatized for unrelated disease and micro-CT revealed solid bone bridging through the inner scaffold tunnel.This study showed the successful application of the design, fabrication and clinical use of a patient-specific 3D-printed titanium implant to repair segmental bone defects of the antebrachium in two dogs.

Drug delivery platforms that allow for gradual drug release after intra-articular administration have become of much interest as a treatment strategy for OA. The aim of this study was to investigate the safety and efficacy of an intra-articular sustained release formulation containing celecoxib (CXB), a COX-2 selective inhibitor.Amino acid-based polyesteramide microspheres (PEAMs), a biodegradable and non-toxic platform, were loaded with CXB and employed in two in vivo models of arthritis: an acute inflammatory arthritis model in rats (n=12), and a randomized controlled study in chronic OA dog patients (n=30). In parallel, the bioactivity of sustained release of CXB was evaluated in monolayer cultures of primary dog chondrocytes under inflammatory conditions.Sustained release of CXB did not alleviate acute arthritis signs in the rat arthritis model, based on pain measurements and synovitis severity. However, in OA dog patients, sustained release of CXB improved limb function as objective parameter of pain and quality of life based on gait analysis and owner questionnaires. It also decreased pain medication dependency over a 2-month period and caused no adverse effects. Prostaglandin EThese results show that local sustained release of CXB is less suitable to treat acute inflammation in arthritic joints, while safe and effective in treating pain in chronic OA in dogs.