Human freeze-dried cancellous bone combined with human chondrocyte sheets have recently been used to construct an osteochondral-like tissue, which resembled a cartilage layer on a subchondral bone layer. Nevertheless, the efficacy of these human tissues in a xenogeneic model has been rarely reported. Therefore, this study aimed to evaluate the potential of human freeze-dried cancellous bones combined with human chondrocyte sheets for the treatment of osteochondral defects in rabbits. The key roles of the extracellular matrix (ECM) and released cytokines in these tissues in osteochondral repair were also assessed. Triple-layered chondrocyte sheets were constructed using a temperature-responsive culture surface. Then, they were placed onto cancellous bone to form chondrocyte sheet–cancellous bone tissues. The immunostaining of collagen type II (COL2) and the proteomic analysis of the human tissues were carried out before the transplantation. In our in vitro study, the triple-layered chondrocyte sheets adhered well on the cancellous bone, and the COL2 expression was apparent throughout the tissue structures. From the proteomic analysis results, it was found that the major function of the secreted proteins found in these tissues was protein binding. The distinct pathways were focal adhesion and the ECM–receptor interaction pathways. Among the highly expressed proteins, laminin-alpha 5 (LAMA5) and fibronectin (FN) not only played roles in the protein binding and ECM–receptor interaction, but also were involved in the cytokine-mediated signaling pathway. At 12 weeks after xenogeneic transplantation, compared to the control group, the defects treated with the chondrocyte sheets showed more hyaline-like cartilage tissue, as indicated by the abundance of safranin-O and COL2 with a partial collagen type I (COL1) expression. At 4, 8, and 12 weeks, compared to the defects treated with the cancellous bone, the staining of safranin-O and COL2 was more apparent in the defects treated with the chondrocyte sheet–cancellous bone tissues. Therefore, the human chondrocyte sheets and chondrocyte sheet–cancellous bone tissues provide a potential treatment for rabbit femoral condyle defect. LAMA5 and FN found in these human xenografts and their culture media might play key roles in the ECM–receptor interaction and might be involved in the cytokine-mediated signaling pathway during tissue repair.

Background and Aim: Electrical stimulation (ES) and light amplification by stimulated emission of radiation (LASER) therapy are frequently used in post-operative rehabilitation; however, there is currently insufficient research comparing their effectiveness. This study aimed to assess the effectiveness of post-operative rehabilitation following medial patellar luxation (MPL) surgical correction by comparing ES and LASER therapy when combined with exercise. This was compared with a control group that consisted solely of post-operative home exercise implemented by the owner. Materials and Methods: We conducted a prospective clinical trial on dogs that had undergone surgical treatment for MPL. The dogs were categorized into the following three groups: The control group, which did not participate in any post-operative rehabilitation program; the ES group, which received post-operative rehabilitation involving ES therapy; and the LASER group, which underwent post-operative rehabilitation featuring LASER therapy. Results: There were no significant differences among the groups regarding the evaluation parameters, including lameness score, pain score, thigh muscle circumference, and range of motion. Although there may have been a difference in pain score in some groups, it could be attributed to the pre-operative condition of patients. These results aligned with the owner questionnaires’ canine brief pain inventory assessments, showing no significant differences between treatment groups. Conclusion: Post-operative rehabilitation for MPL correction may enhance limb usage, joint function, muscle mass, and pain relief. However, the duration and level of post-operative pain may influence the necessity for rehabilitation. In addition, ES and LASER therapy offer similar pain-relieving effects after MPL surgery; therefore, the choice between these methods depends on the availability of equipment and veterinarian preferences. Keywords: electrical stimulation, light amplification by stimulated emission of radiation therapy, medial patellar luxation, post-operative management, rehabilitation.

Cranial cruciate ligament rupture (CCLR) is a common cause of stifle joint pain in dogs. This study assessed the short-term outcomes in the management of CCLR, with or without concurrent medial patellar luxation (MPL), in small-breed dogs, comparing surgical intervention using tibial plateau leveling osteotomy (TPLO) with non-surgical approaches. Dogs weighing less than 10 kg and suffering from CCLR were divided into two groups: surgical and non-surgical (nine stifles per group). Both groups followed the same rehabilitation protocol. Measurements were taken on days 0, 14, 28, 42, 56, 70, and 84. These measurements included the mean difference in orthopedic assessment score (diffOAS) and thigh muscle circumference (TMC) assessed by veterinarians, as well as the Canine Brief Pain Inventory score (CBPI) evaluated by the owners. Six stifles had concurrent MPL in the surgical group and five in the non-surgical group. No significant differences were observed in diffOAS (P=0.685), TMC (P=0.557), CBPI pain severity score (P=0.062), and CBPI pain interference score (P=0.29) between the two groups. However, both groups showed a significant decrease (P0.05), but it significantly increased in the surgical group (P<0.05). Both groups demonstrated improved clinical outcomes in the short term, with no significant differences. However, cautious consideration should be given to a conservative treatment in small-breed dogs, particularly when considering the exclusive improvement observed in TMC within the TPLO group.

This study compared injectable platelet-rich fibrin (i-PRF) and platelet-rich plasma (PRP) derived from canine blood, focusing on their cellular content and cytokine profiles to evaluate their suitability for various veterinary clinical applications. Blood samples were collected from 20 client-owned dogs. i-PRF and PRP were prepared using low-speed centrifugation and double centrifugation methods, respectively. Blood cell counts were quantified using automated cell analysers, while growth factors and cytokines were measured using a Luminex assay. The results showed that both i-PRF and PRP significantly reduced red blood cell content compared with whole blood. PRP achieved a 3.81-fold increase in the platelet concentration compared with whole blood, significantly higher than the 1.89-fold increase achieved by i-PRF. PRP also contained significantly higher levels of white blood cells, particularly lymphocytes and monocytes. Growth factor and cytokine profiles between the two products were unexpectedly similar. In conclusion, while PRP demonstrated superior platelet and white blood cell concentrations compared with i-PRF, its preparation process was more complex and time-consuming. Conversely, i-PRF offered the advantages of shorter preparation time and the absence of anticoagulants, making it potentially more suitable for certain clinical applications despite the similarity in growth factor and cytokine profiles between the two products.