Investigate an optimal extracorporeal shock wave therapy intervention strategy for osteonecrosis of femoral head : a retrospective analysis

Abstract

Abstract Purpose: To investigate an optimal ESWT intervention strategy in the management of ONFH. Methods: An analysis of medical records was performed retrospectively on 75 patients who received extracorporeal shock wave therapy(ESWT) between June 2021 and July 2023, all patients affected by ONFH. These patients underwent MRI before treatment, 3 months, and 1 year after treatment to measure their volume; their Harris and VAS were recorded at the corresponding time points. Correlation analysis and regression analysis were performed to examine the correlation between necrotic volume and Harris, VAS before treatment and the correlation between the change of necrotic volume size and the evolution of HHS 1 year after treatment. Results:A statistically significant correlation between the size of the necrotic volume and the Harris and VAS was demonstrated before treatment(P＜0.001). Three months after treatment, there were significant improvements in Harris and VAS(P＜0.001) but unchanged in MRI images. One year after treatment, the Harris, VAS, and size of necrotic volume from 13 patients were significantly improved(P＜0.001), and Linear regression analysis indicated a significant positive correlation between the size of the necrotic volume and clinical improvement(P＜0.001). Conclusion: The volume of osteonecrosis of the femoral head was negatively correlated with Harris and positively correlated with VAS. The reduction of necrotic volume was related to clinical improvement. It shows that the degree of pain is one of the critical references to reflect the size of necrosis and physiotherapists can choose interval between two cycles according to their own changes in pain conditions.