Extracorporeal shock wave therapy with imaging examination for early osteonecrosis of the femoral head: a systematic review.

Background: Extracorporeal shockwave therapy (ESWT) is a traditional non-invasive therapy to treat osteonecrosis of the femur head (ONFH). This systematic review aims to investigate whether ESWT can improve the clinical function of ONFH and whether differences in improvement can be observed in radiographic outcomes.

Materials And Methods: Two authors independently searched PubMed, Embase, Cochrane Library, and Web of Science for English articles until October 21, 2023. After screening and reading the literature, the two authors independently used corresponding scales to evaluate the quality of the included articles and extracted data. The key data extracted included the Harris Hip Score (HHS), Visual Analog Scale (VAS), changes in lesion size, the change in the Association Research Circulation Osseous (ARCO) stage, and bone marrow edema stage.

Results: Nine articles included 468 males and 248 females. The average age was 43.29 years and the mean follow-up time was 15.19 months. After receiving ESWT, five studies involving 146 hips showed a higher HHS (MD=-33.38; 95%CI, -46.31, -20.45), and the difference was statistically significant (P<0.00001). The average VAS before treatment was above 5, but it dropped to 1.2 after ESWT (MD=4.64; 95%CI, 3.63, 5.64), and the difference was statistically significant (P<0.00001). Three studies found no significant differences in the areas of femoral head necrosis before and after treatment with ESWT(MD=9.66; 95%CI, -0.36, 19.67; P=0.06; I2=84%). Two articles showed that the use of ESWT had no significant effect on the change in the ARCO stage (MD=1.11; 95%CI, 0.76, 1.62; P=0.60; I2=0%). Three studies indicated that using ESWT could improve the bone marrow edema symptom in the early stage of ONFH (MD=4.35; 95%CI, 1.32, 14.37; P=0.02; I2=62%).

Conclusion: Based on the current evidence, ESWT shows promise as a therapy to enhance hip function and alleviate pain in the early stage of ONFH. With the advancement of more precise imaging techniques, ESWT can potentially reduce the area affected by ONFH. However, such reduction was not found to be statistically significant at the imaging level. Additionally, ESWT could improve symptoms of bone marrow edema in the early stage. However, no significant change in ARCO grade was observed with ESWT treatment.