Efficacy of extracorporeal shock wave therapy in the treatment of bone marrow edema in different parts of the knee joints

BACKGROUND The purpose of this prospective study was to evaluate the effectiveness of extracorporeal shock wave therapy (ESWT) in reducing symptoms and normalizing imaging features in periprosthetic bone marrow edema syndrome (BMES) of the knee. METHODS The clinical data of 42 patients with knee bone marrow edema syndrome who attended the Department of Joint Surgery of the Affiliated Hospital of Southwest Medical University from January 2021 to December 2023 were collected, and they were divided into three groups according to the different parts of the knee edema: the femur group (26 cases), the tibia group (9 cases), and the patella group (7 cases). The visual analog scale (VAS) of pain, the knee score (HSS) of the Hospital for Special Surgery of the United States, and the area of BME on magnetic resonance imaging (cm2) were observed before and after three months of shock wave treatment in each group. RESULTS Overall VAS score decreased from 5.40 ± 1.624 to 1.57 ± 1.328 before treatment (p < 0.05), and HSS score increased from 83.05 ± 9.063 to 93.00 ± 4.129 before treatment p< 0.05); the area of BMES decreased from 3.876 ± 3.277 cm2 before treatment to 1.294 ± 0.352 cm2 (p < 0.05) before and after treatment. There was no significant difference between the three groups before and after treatment. (p > 0.05) CONCLUSION Overall ESWT is effective in the treatment of periprosthetic BMES, leading to a decrease in VAS scores, an increase in HSS scores, and a significant decrease in the area of bone marrow edema on T2WI of MRI (except for the patellofemoral group where the decrease in the area of bone marrow edema was not statistically significant, but the overall trend was downward).