Abstract Objective To observe the clinical effect of core decompression on knee osteoarthritis with bone marrow edema(BME).Methods The clinical data of 48 patients with knee osteoarthritis complicated with BME who met the inclusion criteria from May 2018 to may 2020 were retrospectively analyzed. There were 26 cases of arthroscopic debridement combined with core decompression (observation group) and 22 cases of drug treatment (control group). The changes of visual analog scale(VAS) of knee, Western Ontario MacMaster Universities Osteoarthritis Index (WOMAC) and bone marrow edema area were observed.Results ① There were 23 cases (47.92%) of medial tibial plateau, 15 cases (31.25%) of medial femoral condyle and 10 cases (20.83%) of lateral femoral condyle. The incidence of medial tibial plateau was significantly higher than that of the other two zones, and the difference was statistically significant (P < 0.05). ② All patients were followed up for an average of 8.25 ± 1.32 months. Two months after treatment and at the last follow-up, the VAS score and WOMAC index of the observation group were higher than those of the control group, and the difference was statistically significant (P < 0.001). ③ The edema area of the two groups was significantly reduced or disappeared after treatment. At the last follow-up, the effective rate of the observation group was better than that of the control group, and the difference was statistically significant (x2 = 25.89, P < 0.001).Conclusion Core decompression in the treatment of knee osteoarthritis with bone marrow edema can effectively relieve pain and improve joint function.