Objective To explore the clinical efficacy of autologous osteochondral transplantation under arthroscopy for localized cartilage injury of the knee joint and evaluate the efficacy by magnetic resonance imaging （MRI）. Methods From June 2018 to June 2021，100 patients with localized cartilage injury of the knee joint were divided into study group and

control group according to random number table method， with 50 cases in each group. The research group underwent

arthroscopic autologous bone and cartilage transplantation， while the control group underwent microfracture surgery. The

surgical efficacy was evaluated using MRI and the healing time of the knee joint cartilage after operation was recorded.

Lysholm knee joint function scoring table and the International Knee Joint Literature Committee （IKDC） scoring table were

used to evaluate the changes of knee function before and after operation. The incidence of postoperative complications was

analyzed. Results The excellent and good rate of articular cartilage healing in the study group was 98.00%， which was

higher than that in the control group 84.00% （P<0.05）. There was no statistically significant difference in Lysholm score and

IKDC score between the two groups before and 3 months after operation （P>0.05）

. At 6，12， and 24 months after operation，the Lysholm score and IKDC score in the study group were higher than those in the control group （P<0.05）. There were no serious postoperative complications between the two groups， and there was no statistically significant difference in the incidence of complications （P>0.05）. The healing time of knee joint cartilage in the study group was shorter than that in the control group after operation （P<0.05）. Conclusion Arthroscopic autologous osteochondral transplantation has a significant long-term therapeutic effect on localized cartilage injury in the knee joint， which can effectively improve postoperative knee joint function and shorten the healing time of knee joint cartilage with high safety.

Arthroscopy, Autologous osteochondral transplantation, Localized cartilage injury of the knee joint,

Magnetic resonance imaging, Knee joint function