Bone is a tissue that has a density of extracellular matrix structures and composed by organic and inorganic components. Decalcification is a stage that plays an important role in bone histology using various types of solutions. The sample used in this study was lateral condyle from tibia of three garut sheeps (Ovis aries) which had been fixed with 10% Neutral Buffered Formalin (NBF) for 24 hours. Sample were cut into pieces ranging from 1 cm x 1 cm x 1 cm in size, the decalcification using three solutions; 10% nitric acid, 10% EDTA (pH 7.4) and 10% EDTA (pH 7.4) + TBD-1®. The aim of this study was to evaluate the effectiveness of three solutions for the decalcification process of lateral tibial condyle of garut sheep. Observation parameter in this study includes: duration of decalcification, sectioning process of ribboning formation, structural integrity and absorption of hematoxylin-eosin (HE) staining. The results shows that 10% EDTA (pH 7.4) solution provides a long duration of decalcification which is ease sectioning process ribboning, the best structural integrity of lateral tibial condyle. In hematoxylin-eosin (HE) staining shows that 10% nitric acid solution does not absorb the optimum color, opposite in 10% EDTA and 10% EDTA + TBD-1® solution, the color intensity between hematoxylin and eosin in the tissue shows the best results. Based on these results, it can be concluded that the 10% EDTA (pH 7.4) is the best decalcification solution for lateral condyle from tibial of garut sheeps.

Introduction: Autologous mesenchymal stem cells (MSC) implantation suspended in hyaluronic acid (HA) has been proven to delay worsening of articular cartilage degeneration in the knee joint. This has been the treatment of choice for young patients with knee osteoarthritis (KOA); however, it is associated with morbidities such as requirement of multiple procedures, donor site morbidity and failure in achieving cultured cells with chondrogenic properties. Our study investigates the possibility of direct intra articular injection of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) for sheep models of meniscectomy-induced osteoarthritis. Methods: Twelve sheeps with the same characteristics was osteoarthritically induced with lateral meniscectomy and a series of routine exercise. Those sheep were divided into four groups with 3 sheep each. The groups are the control group, intra articular HA (hyalgan G-F 20; Synvisc®) injection group, intra articular hUC-MSCs group, intra articular hUC-MSCs suspended in HA group. The sheeps were sacrificed four weeks post-treatment for gross pathology and histopathology graded according to the Osteoarthritic Research Society International (OARSI) system. Results: The intra articular hUC-MSCs suspended in HA group showed better gross pathology and histopathology grade compared to control groups (p<0.05) according to the OARSI system. The hUC-MSCs suspended in HA group microscopically showed superior chondrocyte number and varying degrees of cellular regeneration of articular cartilage. Conclusion: The use of intra articular hUC-MSCs suspended in HA is an option in treating KOA. Its efficacy in articular cartilage regeneration would be further explained in clinical trials.