Research progress of extracorporeal shock wave therapy for plantar fasciitis

ZHONG Yuan-ming, YE Wei-quan, QIU-Wei, ZHAO Qing-rui, HUANG Yong,FU Xiaopeng, WAN Tong, HE Bing-kun

1.The First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine, Nanning 530023 China

2.Graduate School of Guangxi University of Traditional Chinese Medicine, Nanning 530001 China

Keywords:

ABSTRACT Plantar fasciitis is a common and frequently occurring disease in clinic.It is a kind of local aseptic inflammation caused by chronic strain.In severe cases, pain is unbearable, which affects the quality of life of patients.Extracorporeal shock wave (ESW) is a new noninvasive treatment for bone and muscle diseases.It can significantly relieve the pain and other symptoms of patients with plantar fasciitis, and promote the functional recovery of patients.In order to provide reference for the clinical treatment of plantar fasciitis, this paper reviews the literature of extracorporeal shock wave treatment of plantar fasciitis at home and abroad.

1.Introduction

Plantar fasciitis is a kind of chronic aseptic inflammation of plantar soft tissue.The main symptoms of the patients are burning pain, stabbing pain, or knife like pain in the heel or plantar part.The symptoms worsen when they stand for a long time or walk far away.The serious cases can last for several months or even years.The incidence of plantar fasciitis is mostly related to high arch, flat foot, long and short legs, excessive exercise, long standing time,improper wearing shoes, etc.It is believed that repeated trauma leads to micro rupture of fascia, gradual degeneration of collagen,and degeneration and necrosis of plantar fascia[3].The incidence rate of plantar fasciitis is about 10%[4, 5], most commonly seen in middle-aged people aged 40-60.About 80% of heel pain is caused by PF, and is the most common cause of heel pain[6].Except for a few patients with plantar fasciitis who need surgical treatment, most plantar fasciitis can be treated conservatively[7].Because plantar fasciotomy not only has a recurrence rate as high as 30%, but also is prone to complications such as lateral column pain and nerve injury[8, 9].Therefore, conservative treatment is the first choice.Conservative treatment includes extracorporeal shock wave therapy,traction training, foot orthosis, intramuscular adhesive tape and other non-invasive treatment, and corticosteroid injection, traditional Chinese medicine needle knife and other invasive treatment[10,11].Extracorporeal shock wave (ESWT) is a non-invasive treatment for bone and muscle diseases, which is safe and effective for plantar fasciitis[12].Modern studies have shown that extracorporeal shock wave can relieve pain, affect cell proliferation and differentiation,dilate and repair blood vessels, and have anti-inflammatory effects[13].This paper discusses the mechanism and clinical research of shock wave in the treatment of PF to provide reference for the clinical use of shock wave in the treatment of plantar fasciitis.

2.Mechanism of extracorporeal shock wave therapy for plantar fasciitis

2.1 Mechanical stress effect

Extracorporeal shock wave can produce tensile stress and compressive stress by pressing and withdrawing pressure at the junction of different media such as human soft tissue and bone tissue, so as to decompose adhesion, accelerate capillary circulation,and increase tissue oxygen uptake[14].

2.2 Cavitation effect

There are small bubbles at the junction of tissues (media) with different densities of human body.The high-energy shock wave generated by shock wave will cause cavitation effect and generate pulse wave when transmitted in such media.The pulse wave can make the tiny bubbles in human tissue expand rapidly, open up the occluded microvessels, and achieve the effect of dredging blood vessels and releasing adhesion[15].

2.3 Analgesic effect

The analgesic mechanism of extracorporeal shock wave is still unclear.Some scholars believe that high-intensity shock wave can change the free radicals around cells and release pain inhibitory substances; Some scholars believe that ESWT can relieve pain by changing the frequency of nociceptor reception and the composition of chemical substances and inhibiting the transmission of pain information[17].Other scholars believe that shock wave can change the release of substance P, change the permeability of cell membrane,and can transfect endogenous endorphin precursor gene to achieve analgesic effect[18]; Other studies have shown that shock wave can promote ion exchange inside and outside the cell membrane, thus accelerating the elimination and absorption of metabolites[19, 20].

3.The effect of simple ESW in the treatment of PF

3.1 Low energy shock wave

Low energy extracorporeal shock wave is a relatively new therapeutic tool, which has been widely used in the treatment of plantar fasciitis.Low energy shock wave therapy has been proved to be effective in reducing the immune response of acute wounds, which can reduce the invasion of macrophages and polymorphonuclear leukocytes into the wound area, and inhibit the production of proinflammatory cytokines and chemokines in the wound matrix,similar to the effect of shock wave on inducing angiogenesis in tissues[21,22].Yin M C et al.[23] found that low intensity ESWT can relieve the short-term pain of patients with chronic refractory plantar fasciitis.Rompe J D et al.[24] proved that low energy shock wave therapy may be an effective treatment for plantar fasciitis, which can help patients avoid surgery due to intractable heel pain.ESWT seems to have different effects on peripheral nerves and has been proved to promote axonal regeneration after axotomy[25].Mittermayr et al.[26] considered that low-energy extracorporeal shock wave was beneficial to tissue repair and regeneration.Ibrahim et al.[27] proved that low energy shock wave can significantly improve the symptoms of patients with plantar fasciitis and reduce the recurrence rate.

3.2 High energy shock wave

Metzner g et al.[28] used 1000 shock wave pulses (frequency is 2 per second, energy flux density (ED) is 0.35 MJ/mm at 10.5 kV), The total dose was 350 MJ/mm²) Patients with plantar fasciitis were treated and followed up after 6 weeks of ESWT treatment.The results showed that high energy ESWT (0.35 MJ / mm²) It has a significant effect on the treatment of plantar fasciitis, and can maintain the short-term effect.Li Z et al.[29] found that heswt had a significant effect in the treatment of refractory plantar fasciitis through meta-analysis, and suggested that heswt should be used as a remedial measure after the failure of traditional conservative treatment and before surgical intervention.Gezginaslan m et al.[30] explored the effects of the treatment density and times of extracorporeal shock wave on pain, fatigue, disability, physical function and quality of life of patients with plantar fasciitis.94 patients diagnosed as PF were divided into three groups.Group 1 (n= 33) received a total of 7 times of high energy flux density (h-eswt)(0.26 MJ/mm2), Group 2 (n = 31) received a total of 3 h-eswt (0.26 MJ / mm2) MJ/mm2, and group 3 (n = 30) received a total of 7 lowenergy shock wave treatments.The results showed that multiple courses of h-eswt was more effective than less times of leswt in relieving pain, and the quality of life and disability of patients with PF were significantly improved.

3.3 Divergent shock wave

Fan Zhiying et al.[31] compared the treatment of chronic plantar fasciitis with dispersive extracorporeal shock wave and local sealing respectively, the results showed that: compared with the local sealing group, the effective rate was 57.14%, and the effective rate of extracorporeal shock wave group was as high as 85.71%, which proved that the dispersive extracorporeal shock wave treatment of PF had obvious advantages in maintaining long-term curative effect.Nie Honggu et al.[32] divided 60 patients with plantar fasciitis into divergent shockwave group (n = 30) and ultrasonic group (n= 30).The two groups were treated with divergent shockwave and ultrasonic respectively.Results the NRS and RM scores of divergent shockwave group were significantly lower than those of ultrasonic group (P ＜ 0.05).It is proved that the effect of divergent shock wave in the treatment of plantar fasciitis is better, and its effect is rapid and significant.Sun Dehai et al.[33] used divergent shock wave to treat 48 cases of PF, and the results showed that the effective rate was as high as 91.67%.The results showed that divergent shock wave had good curative effect on chronic plantar fasciitis, and could significantly improve foot function.

3.4 Focused shock wave

Lohrer et al.[34] compared the treatment of PF with focused extracorporeal shock wave and scattered extracorporeal shock wave,the results showed that the clinical effect of focused extracorporeal shock wave in the treatment of refractory plantar fasciitis was better.Speed, C [35] and others searched the literature to evaluate the evidence of shock wave therapy for pain treatment of specific soft tissue injury, and found that focused shock wave can effectively treat plantar fasciitis.Fang Jianhui et al.[36] compared the conventional rehabilitation therapy and the athletes with PF treated with extracorporeal shock wave on the basis of rehabilitation therapy,the results showed that the VAS score of the treatment group treated with extracorporeal shock wave was significantly lower than that of the conventional rehabilitation group (P ＜ 0.05), which proved that extracorporeal shock wave could significantly relieve the pain and other symptoms of athletes with chronic plantar fasciitis, and the clinical effect was better.

4.The curative effect of ESW combined with traditional Chinese medicine in the treatment of PF

Plantar fasciitis is a common disease in orthopedics and traumatology, which belongs to the category of “Bi disease” and“Jin Bi” in traditional Chinese medicine.The cause of this disease is long walking and standing, excessive exercise, and feeling wind cold and dampness evil, which leads to qi stagnation and blood stasis in the affected area, blockage of muscles and veins, or deficiency of liver and kidney, insufficient body fluid, and pain if not proud.It is suitable for promoting blood circulation and dredging collaterals,removing blood stasis and relieving pain[37].Shock wave combined with traditional Chinese medicine in the treatment of plantar fasciitis not only has the characteristics of significant curative effect, small side effects and safety, but also can play an immediate effect and get twice the result with half the effort.

4.1 ESW combined with acupuncture in the treatment of PF

Acupuncture has the function of relaxing tendons, dredging collaterals, removing blood stasis and relieving pain[38].Modern studies have shown that the analgesic process of acupuncture and moxibustion is closely related to neurotransmitters, conduction pathways, immune inflammatory factors and so on[39].Shock wave combined with acupuncture in the treatment of plantar fasciitis has significant effect in relieving pain, which is conducive to the functional recovery of patients.Bagcier f et al.[40] divided 40 patients with plantar fasciitis into two groups.The shock wave dry needle group (eswt-dn group) used the dry needle at the trigger point of gastrocnemius muscle on the basis of using shock wave, while the shock wave group only used ESWT.The results showed that the VAS score, the maximum painless standing time, the maximum painless walking distance and the pain score of FFI in eswt-dn group were better than those in shock wave group (P ＜ 0.05).It is proved that ESWT combined with DN can significantly relieve the pain and other symptoms of patients with plantar fasciitis, and promote the rehabilitation of patients.Wang Junhua et al.[41] compared the treatment of PF with electroacupuncture and shock wave group, the results showed that the cure rate of the combined treatment group receiving both electroacupuncture and ESWT was significantly higher than that of the electroacupuncture group and shock wave group, which proved that the short-term and long-term efficacy of ESWT combined with Electroacupuncture in the treatment of plantar fasciitis was significant.Su Jian et al.[42] found that the total effective rate of shock wave combined with electroacupuncture (93.8%) was significantly better than that of shock wave alone (83.3%) (P ＜ 0.05),and it can effectively relieve the pain of patients with chronic plantar fasciitis and improve the quality of life of patients.

4.2 ESW combined with external application of traditional Chinese medicine in the treatment of PF

External use of traditional Chinese medicine refers to the external use of traditional Chinese medicine which has the effect of promoting blood circulation and removing blood stasis, such as paste, liquor, hot treatment bag, etc., to achieve the therapeutic effect of removing blood stasis, generating new, detumescence and pain relief.External application of traditional Chinese medicine can not only eliminate soft tissue edema, relieve pain and promote tissue repair, but also avoid the toxic side effects of liver and kidney, so it is safe and reliable.ESW combined with external use of traditional Chinese medicine has a significant effect in relieving pain and promoting soft tissue repair, which can greatly improve the recovery of foot function.Li jionghua et al.[43] found that the clinical effective rate of shock wave combined with external application of traditional Chinese medicine in the treatment of plantar fasciitis (100.00%)was significantly better than that of local blocking (65.52%), which proved that receiving external shock wave and external application of traditional Chinese medicine at the same time can not only significantly relieve the pain symptoms of patients with plantar fasciitis, but also eliminate the adverse reactions caused by shock wave treatment.Zhang Rui et al.[44] proved that traditional Chinese medicine fumigation combined with extracorporeal shock wave in the treatment of plantar fasciitis is significantly better than traditional Chinese medicine fumigation or extracorporeal shock wave alone,and its long-term effect is significant, which is conducive to the recovery of the disease.Li Huan et al.[45] discussed the clinical effect of Siwu Siteng decoction combined with shock wave in the treatment of plantar fasciitis.Results in 30 cases, 10 cases were cured, 12 cases were markedly effective, 6 cases were improved, 2 cases were ineffective, and the total effective rate was 93.33%.It is proved that siwusiteng decoction combined with shockwave can effectively improve the clinical symptoms and quality of life of patients with plantar fasciitis.Li Zhiyuan et al.[46] observed the clinical efficacy of self-made Chinese medicine prescription combined with shock wave in the treatment of plantar fasciitis, and the total effective rate was 94.00%.It is proved that the effect of traditional Chinese medicine combined with shock wave in the treatment of plantar fasciitis is significant, which can significantly improve the clinical symptoms of patients.

5.Efficacy of ESW combined with western medicine in the treatment of PF

At present, there are many methods to treat plantar fasciitis with western medicine, such as orthopedic insole, sealing, traction training, laser, intramuscular effect sticking and so on.ESW combined with western medicine is mainly combined with orthopedic insole and stretching therapy, which can significantly improve the clinical symptoms and promote the functional recovery of patients.

5.1 ESW combined with orthopedic insole in the treatment of PF

Orthopedic insole can effectively relieve the clinical symptoms of PF and promote the rehabilitation of foot function.Orthopedic insole can make the abnormal biomechanical distribution tend to be normal,so as to reduce the mechanical stimulation to the affected area and relieve pain[47].Wrobel et al.[48] found that orthopedic insoles can improve the walking time, body balance ability and physical activity of patients with plantar fasciitis.Walther and other scholars[49, 50, 51, 52] also found that orthopedic insoles can effectively relieve the pain of patients with plantar fasciitis.Orthopedic insole combined with shock wave can enhance the curative effect, which can relieve the pain of patients and improve the walking time of patients with plantar fasciitis.Fang Zhengyu et al.[53] compared the efficacy of ESW combined with orthopedic insole and conventional rehabilitation in the treatment of plantar fasciitis, and found that the VAS score and the longest sustainable walking time of patients with ESW combined with orthopedic insole were better than those of conventional treatment (P ＜ 0.05).It is proved that the clinical effect of ESW combined with orthopedic insole in the treatment of plantar fasciitis is significantly better than that of conventional rehabilitation treatment.Yan Wenguang et al.[54] found that the cure rate and total effective rate of extracorporeal shock wave combined with orthopedic insole were significantly better than that of simple shock wave and orthopedic insole, proving that extracorporeal shock wave combined with orthopedic insole can significantly relieve the pain and other symptoms of patients with plantar fasciitis, and improve the foot function of patients.

5.2 ESW combined with stretching therapy in the treatment of PF

Meng Qingcai et al.[55] compared the efficacy of traction training alone (control group) and traction training combined with ESWT(treatment group) in the treatment of plantar fasciitis.Results the AOFAS score of the treatment group was higher than that of the control group (P ＜ 0.05), and its VAS score was lower than that of the control group (P ＜ 0.05).It is proved that the stretching therapy combined with ESWT can effectively relieve the pain symptoms and improve the ankle function of patients with PF,.Zhang Longhao et al.[56] compared the treatment of plantar fasciitis between extracorporeal shock wave group (control group) and extracorporeal shock wave combined with plantar traction training group (experimental group).Results after 12 weeks of treatment,the cure rate of the experimental group (41.7%) was significantly better than that of the control group (34.8%), and the effective rate of the experimental group (100%) was significantly better than that of the control group (86.9%).It is proved that the long-term effect of extracorporeal shock wave combined with foot traction training is more significant.

5.3 ESW combined with other Western medicine therapy for PF

Jin Mingliang et al.[57] observed the clinical efficacy of conventional rehabilitation, extracorporeal shock wave, extracorporeal shock wave combined with intramuscular effect sticking in the treatment of PF, and found that extracorporeal shock wave combined with intramuscular effect sticking can significantly improve the balance function of patients with plantar fasciitis, relieve pain, improve the quality of life, and maintain short-term, medium and longterm effects.Li Xiaohong et al.[58] compared shockwave therapy with shockwave combined with semiconductor laser irradiation,and found that the cure rate of shockwave combined with laser was higher, which proved that laser combined with shockwave had significant effect on plantar fasciitis, and the long-term effect was better.Yang Jian et al.[59] divided 74 cases of PF into treatment group and control group, the total effective rate was 83.78% compared with the control group only using semiconductor shortwave.The total effective rate of shock wave combined with semiconductor short wave was 91.89% (P＜0.05), which proved that shock wave combined with semiconductor short wave could significantly relieve the pain of patients with plantar fasciitis and improve the quality of life of patients.

6.Thinking of extracorporeal shock wave in the treatment of plantar fasciitis

Extracorporeal shock wave therapy is a non-invasive treatment method[60], known as “bloodless scalpel”.After it acts on the body surface, it can relieve pain through the physical effects produced by local tissue and the regulation of microcirculation, nervous system and inflammatory factors.Although the mechanism of extracorporeal shock wave therapy for PF has not been fully understood, its efficacy and safety have been confirmed by the majority of clinicians.Extracorporeal shock wave (ESW) has the characteristics of small side effects, safety and definite curative effect.It can significantly improve the clinical symptoms of patients with plantar fasciitis and promote the rehabilitation of patients.For some patients with long course and severe symptoms, shock wave combined with other therapies has better clinical effect.Therefore, we should choose the best treatment according to the patient’s condition, so as to achieve the best clinical effect.At present, the frequency and energy of shock wave therapy for plantar fasciitis are still controversial, and there is no unified standard.However, with the development of basic research and clinical trials of shockwave, the use of ESW in the treatment of PF will be more standardized in the future.