Regenerative medicine based on Mg alloy implants is considered a modern approach to address bone defects. It represents a promising alternative to traditional grafting strategies (auto-, allo-, and xenografts) by potentially mitigating complications such as donor-site morbidity and limited supply, which are discussed in this paper. In line with this global topic, attention is devoted to an innovative manufacturing route for Mg-Nd and Mg-Zn implants for the treatment of small bone defects. First, the proposed manufacturing method is described in detail, including the materials used and the manufacturing steps, and then a comparison between the reference (cast alloys) and implant samples is performed. The mechanical properties, weight loss in simulated body fluid (SBF), surface analysis (contact angle and roughness measurements), and cytotoxicity were evaluated to determine whether the developed implants are suitable for consideration as future bone implants. The main conclusions of the study were that both Mg-based implants exhibited mechanical properties (compressive strength and Young’s modulus) with values very close to those of the human bone, reduced mass loss (a fact that is in a direct relationship with an increase in corrosion resistance due to MgF₂ conversion coating, which is a secondary result of the proposed manufacturing route), and finally, a good biocompatibility sustained by cell culture and cytotoxicity assessment, as well as by apoptosis and necrosis analysis on a human patella-derived osteoblastic cell line.

Mg-based alloys are one of the most promising materials used in regenerative medicine for bone tissue engineering. Considering the increasing prevalence of a continuously aging population, as well as the high incidence of accidents and bone cancers, it is crucial to explore biomaterials that can serve as bone substitutes. After carefully analyzing the literature in the introduction section, we proposed two Mg-based alloys as suitable for obtaining biodegradable structures for bone defect treatment. To achieve trustworthy results, the alloys’ microstructure was investigated using microscopic techniques coupled with energy-dispersive spectroscopy and X-ray diffraction. The obtained results were comparable with those described in references on similar Mg alloys. Then, the mechanical compression properties were highlighted, and the in vitro corrosion behavior proved that Mg-Zn exhibited a reduced corrosion rate compared to the Mg-Nd alloy, as tested using electrochemical methods. However, the in vivo tests showed good biocompatibility for both magnesium alloys. In conclusion, both alloys are suitable for use as potential bone substitute applications, but it must be taken into consideration that Mg-Zn alloys present lower biodegradation and mechanical properties. For future investigations, we aim to develop bone substitutes made from these materials, specifically designed for small bone defect treatment and with patient-adapted geometry. Due to the differences mentioned above, various designs will be tested.

Aim of the Study: This review investigates the use of antibiotic-loaded biomaterials in the treatment of osteomyelitis, with a focus on preclinical studies involving rat models. These models are widely used to assess local drug delivery, antibacterial effectiveness, and bone regeneration. Materials and Methods: A literature search was conducted to identify in vivo studies from the past decade using rat models of osteomyelitis treated with antibiotic-loaded biomaterials. Studies were analyzed based on biomaterial types, infection models, assessment methods, and treatment outcomes.Results: Rat models provide a reliable platform for evaluating the antimicrobial and regenerative effects of biomaterials. Materials such as calcium sulfate and mesoporous glass demonstrated promising results in localized antibiotic delivery and bone healing. Conclusions: Antibiotic-loaded biomaterials show strong potential in osteomyelitis management. Rat models play a key role in their development and preclinical validation. Further research should focus on multifunctional scaffolds and standardized testing protocols to improve clinical translation.

Background and Objectives: Magnesium-based biomaterials are increasingly investigated due to their biodegradability, bone-like elastic modulus, and potential osteogenic properties. However, alloy composition may influence degradation behavior and local tissue response. This study aimed to assess and compare the local biocompatibility, degradation characteristics, and bone regenerative response induced by Mg-Zn-Mn-Ca and Mg-Nd-Y-Zr-Zn magnesium alloy powders. Materials and Methods: Two magnesium alloys were evaluated through physicochemical characterization, in vitro osteoblast cytocompatibility and antimicrobial assays, and in vivo testing in Sprague–Dawley rats. Standardized cylindrical defects were created in the medial femoral condyle and filled with either Mg-Nd-Y-Zr-Zn or Mg-Zn-Mn-Ca alloy powders, while untreated defects served as controls. Bone remodeling and defect healing were assessed by micro-computed tomography, allowing three-dimensional qualitative and quantitative evaluation of newly formed bone. Scanning electron microscopy was used to analyze surface morphology and degradation features, while histopathological examination assessed inflammation, osteogenesis, and tissue integration at the implant site. Results: Both magnesium alloy powders showed antimicrobial potency and elicited no cytotoxic effects in vitro, while animal studies revealed progressive biodegradation over time, associated with new bone formation within and around the defect area. Micro-CT analysis demonstrated active bone remodeling in experimental groups, with differences in bone distribution and defect-filling patterns between Mg-Nd-Y-Zr-Zn and Mg-Zn-Mn-Ca implants. SEM revealed alloy-specific degradation morphologies. Histological evaluation showed a moderate early inflammatory response that decreased at later time points, together with ongoing osteogenesis and favorable tissue integration. No severe local adverse reactions or persistent inflammation were observed. Conclusions: Both Mg-Nd-Y-Zr-Zn and Mg-Zn-Mn-Ca alloy powders were locally biocompatible and supported bone regeneration in a rat femoral condyle defect model. Differences in degradation behavior and tissue response emphasize the relevance of alloy composition in developing magnesium-based biomaterials for bone defect treatment.

Grade IV lateral patellar luxation is an advanced orthopedic condition that may be associated with severe skeletal deformities, chronic soft-tissue contracture, and irreversible loss of normal stifle function. Although reconstructive procedures are considered the treatment of choice in most dogs, some end-stage cases may not be amenable to conventional correction. This report describes the clinical presentation, surgical management, and long-term outcome of a young dog with severe bilateral grade IV lateral patellar luxation treated with single-stage bilateral stifle arthrodesis. A 1-year-old, 42-kg intact female Romanian Shepherd Dog was presented with chronic severe hindlimb dysfunction, crouched posture, and permanent bilateral patellar luxation. Orthopedic and radiographic examination revealed severe femoral valgus, proximal tibial varus, external tibial torsion, absence of a functional trochlear groove, marked caudal thigh muscle contracture, and severely restricted stifle extension. Computed tomography was considered but not performed because of financial limitations. Based on the severity of the deformities and the limited preoperative range of motion, conventional reconstructive procedures were considered unlikely to restore functional joint motion. Bilateral stifle arthrodesis was therefore performed during a single anesthetic event using tibial tuberosity osteotomy, temporary Kirschner-wire fixation, and bilateral 3.5-mm locking compression plates. Due to severe chronic soft-tissue contracture, final arthrodesis angles of 95° and 99° were achieved. Progressive clinical improvement and radiographic bone union were observed throughout follow-up. At 12 months, complete bilateral arthrodesis and implant stability were confirmed radiographically. At 24 months, the dog remained independently ambulatory with a markedly improved quality of life despite persistent mechanical gait abnormalities, including circumduction and intermittent bunny-hopping. This case suggests that bilateral stifle arthrodesis may represent a salvage option in carefully selected dogs with end-stage bilateral grade IV lateral patellar luxation when conventional reconstructive procedures are unlikely to restore useful limb function.