Effects of intraarticular vitamin D use on cartilage healing

Objective: In this study, the effect of intraarticular vitamin D injection on the healing of a circular chondral lesion formed in a full layer of medial femoral condyle articular cartilage in accordance with the model of knee cartilage defect in rabbit was examined. Method: Twelve rabbits were used in the study. 6 rabbits in each group were planned as the experimental group for intraarticular vitamin D injections, and the control group for intraarticular saline injection. During the study process, 2 rabbits from the experimental group, 1 rabbit from the control group died, and 1 animal from the control group broke the condyle while micro-fractures were performed during surgery, the study continued with a total of 8 rabbits (8 knees) with 4 rabbits in each group. 4x4mm osteochondral defects were created to the medial condyles of the left knees of rabbits in both groups and then micro-fractures were applied with K wires. Postop to rabbits 7., 14. and on the 21st day, three intra-knee injections were applied.At the end of the sixth week, the rabbits were sacrificed. The left knee femoral condyles of the rabbits were removed and the samples were fixed with a 10% solution of formalin. Findings: According to the ICRS cartilage repair Assessment Scale, two of the samples in the experimental group were found to be Stage 2 (close to normal) and two to Stage 1 (normal). In the control group, three samples were found in Stage 2(close to normal) and one sample in Stage 4 (Advanced abnormal). According to the ICRS cartilage repair assessment scale, the difference between the groups was not statistically significant.According to the macroscopic scoring system, the difference between the groups in terms of fill score and surface score was not significant, but a significant difference in terms of color score was found. (p = 0.013) In histopathological examination, groups were compared in terms of immature cartilage, mature cartilage and fibrosis observed at the site of the lesion. In the experimental group, the development of immature cartilage and mature cartilage was significantly different from the control group (p=0.003, p=0.013), while the development of fibrosis was significantly higher in the control group than in the experimental group. (p=0.022) Result: In rabbits with a full-fold articular cartilage defect, intra-articular vitamin D injection was observed to have a positive effect on the formation of mature cartilage and immature cartilage at an early stage. It is believed that longer follow-up and more comprehensive studies are needed for late-stage results.