Extracorporeal shock wave therapy for bone marrow edema syndrome in patients with osteonecrosis of the femoral head: a retrospective cohort study

Wenyi Zhao,Lin He,Dahong Zhang,Wei Li,Zhang Liu,Qinggang Meng,Shouxiang Zhang,Yuan Gao

doi:10.1186/s13018-020-02159-7

Abstract

BackgroundThere is now ample evidence suggesting that extracorporeal shock wave therapy (ESWT) can improve hip mobility and reduce pain in patients with osteonecrosis of the femoral head (ONFH). The ability of ESWT to cure bone marrow edema syndrome (BMES) in patients with ONFH, 12 weeks after the initial course of ESWT, needs to be verified further and more relevant clinical research-based evidence should be consolidated. This study aimed to evaluate the efficacy of ESWT for BMES caused by ONFH.MethodsThis retrospective cohort study included 67 patients with BMES caused by ONFH who were participating in a rehabilitation program as outpatients. Before and after ESWT, the area of femoral bone marrow edema was evaluated by magnetic resonance imaging (MRI), and the Harris score and Charnley score were evaluated as hip pain and function indicators.ResultsAfter ESWT, MRI revealed that the area of bone marrow edema decreased from 984.6 ± 433.2 mm2 to 189.7 ± 214.4 mm2 (P < 0.0001). The Harris score increased from 42.2 ± 9.1 to 77.7 ± 10.8 points (P < 0.0001). The Charnley score increased from 7.3 ± 1.4 to 12.0 ± 1.7 (P < 0.0001). ESWT was effective in treating BMES in 98.5% of the cases.ConclusionsThis study demonstrated that ESWT can effectively treat BMES caused by ONFH and can aid in pain relief and functional recovery in patients with ONFH. Thus, ESWT should be included in the classic physical therapy regimen for patients with ONFH and BMES.

Highlights

There is ample evidence suggesting that extracorporeal shock wave therapy (ESWT) can improve hip mobility and reduce pain in patients with osteonecrosis of the femoral head (ONFH)
ESWT has been used to treat bone marrow edema syndrome (BMES) caused by Osteonecrosis of the femoral head (ONFH) [21]
Sample size calculation The sample size was estimated to be 4 recipients, in line with the qualitative response parameters (α= 0.05, double; power of test 1- β = 0.9; power = 0.9923). This retrospective cohort study included 67 patients with BMES caused by ONFH, more than the sample size number

Summary

Introduction

There is ample evidence suggesting that extracorporeal shock wave therapy (ESWT) can improve hip mobility and reduce pain in patients with osteonecrosis of the femoral head (ONFH). ONFH is caused by a variety of disorders of local blood circulation in the femoral head, resulting in the death of the active components of the bone (bone cells, bone marrow cells). This eventually leads to the destruction of the trabecular bone in the femoral head, the collapse of the femoral head, and the loss of joint function [3]. Studies have shown that the hip pain symptom classification of ONFH patients positively correlates with the degree and area ratio of bone marrow edema [6]. The increase of bone-like and the decrease of hydroxyapatite content can explain the decrease of bone density on a radiograph

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