How type 2 collagen combination impregnated injectable hyaluronic acid-based implant affect cartilage repair? experimental study in rats.

Absract: İnvestigation of effect of hyaluronic acid and type 2 collagen therapy and recovery duration in cartilage lesions of rat knees Material method: Right knee of 32 wester albino species rats were used in study.32 rats were divided into 4 groups with each count was 8.Group names were: microfracture, hyaluronic acid,type 2 collagen and Combined. Microfracture was done by 0.8mm k wires to both cartilage and subchondral bone of medial condyle in right knees of rats with paramedian incision approach.The Microfracture Group were left to recovery follow up.Single dose of 0.4 ml HA intraarticular injection was done following surgery in Hyaluronic Acid Group. Single dose of 30 microgram T2C intraarticular injection was done following surgery in Type 2 Collagen Group.T2C and HA were together applied in Combined Group. İn the end of first month 4 rats from each group were sacrificed.Distal femur of them were excised and sent to lab for histopathological examination.Rats who were left were also sacrificed in the end of second month for the same application. The bone specimens were fixed in %10 neutral formalin after decalcification with %3 nitric acid in lab.After 7 days of fixation specimens were histologically followed up with Leica TP1020 automatic tissue follow up device and then buried into paraffin.5 µ width cut sections from paraffin were applied onto thin plates.İn order to detailed evaluation of bone,connective tissue and type 2 collagen they were stained by Van Gieson's method and investigated under light microscope Nikon E-600.The recovery quality and cartilage formation in fracture site were evaluated by classic cartilage tissue recovery classifications of O'Driscoll and Modified Mankin in evaluation process.İn evaluation process the written criterias were used as follows. One Way ANOVA statistical analysis test were applied to determine the statistical differences between group values.''SPSS for Windows 23.0''statistical analysis program was applied for evaluation. Results: The values obtained for each group were symmetrical to each other in both O'Driscoll and the Mankin classifications, which was evidence of the results and the validity of the methodology. It was observed that the healing in the HA group and in the Combined 2month group were very close to the values of the Microfracture group.İnterestingly, the healing in HA 2 month group was found to be very low in comparison to other groups. This indicates the acute effect of HA is more prominent and demonstrates the necessity of additional doses in long term therapies. İn the other hand, higher values in the combined group and in the combined 2month group and more increase in the combined 2month group than in the combined group were evaluated as improvement in the positive direction of the continuous dose dependent treatment. Conclusion: As a result of our study, it can be predicted that the use of hyaluronic acid in combination with type 2 collagen instead of hyaluronic acid alone is valuable to open new studies. In addition, the use of microfracture in cartilage damage combined with other treatment options may bring to better results. It should be kept in mind that multifactorial effects and numerous biological cascades are effective in cartilage healing