The shockwave therapy with 6,000 impulses at 28 kV (0.62 mJ/mm2) in a single session was used to treat 35 patients (47 hips) with ONFH [30]. Data showed that the local ESWT application resulted in significant systemic elevations of serum nitric oxide level, angiogenesis (vascular endothelial growth factor, VEGF; Von Willebrand factor, vWF; and fibroblast growth factor-basic) a decrease of transforming growth factor beta (TGF-β1), an increase of osteogenic markers (bone morphogenetic protein 2, BMP-2; osteocalcin, alkaline phosphatase and insulin-like growth factor), and a decrease of Dickkopf-related protein 1 (DKK1) and anti-inflammatory factors (soluble intercellular adhesion molecule and soluble vascular cell adhesion molecule, sVCAM) at 1 month after ESWT. In another study, they found the application of shockwave results in regeneration effects in 7 hips with ONFH with significantly more viable bone and less necrotic bone, higher cell concentration cell activity including phagocytosis and increases in vWF, VEGF, and CD 31 and Winless 3a and proliferating cell nuclear antigen, and decreases in VCAM and DKK1 [31]. When patients with SLE were affected by ONFH, ESWT also demonstrated its effectiveness with improvement in hip pain and function and image changes on X-ray and MRI in 15 SLE patients with 26 hips [32]. Besides the above, the effects of different dosages of ESWT were reported in early ONFH [19]. High-dose ESWT (6,000 impulses at 24 Kv [0.510 mJ/mm2]) is more effective than low-dose energy (2,000 impulses at 24 Kv) in systemic beneficial effects such as enhancement of angiogenesis with improvement of microcirculation of the peri-necrotic areas. In turn, high-dose ESWT can improve subchondral bone remolding and prevent femoral head collapse more effectively than low-dose therapy in early ONFH. However, in 2016, Han et al. [33] reported lower energy density ESWT in the treatment of early stage of ONFH with 6-month follow-up. They showed ESWT indeed has a significant effect in treating the symptoms of ONFH, but there was no significant difference between the two groups (1,000 shocks/session, EFD per shock 0.12 and 0.32 mJ/mm2, 4 sessions), regardless of the difference in EFD.
To summarize the results of previous researches, there is still no standard protocol of ESWT for clinical application in ONFH. Part of the reasons is due to the fact that the success rate of treatment in ONFH is more dependent on the stage of this disease. Many experimental and clinical researches tried to preserve the hip joint and prevent the progression to the secondary degenerative change during the early stage of ONFH. In order to set a standard procedure of shockwave therapy, the International Society for Medical Shockwave Treatment recommends a protocol, 0.62 mJ/mm2 of EFD in 4,000 impulses delivered to the skin close to the damaged bone for ONFH treatment. Further studies are necessary to assess the optimal timing and dosage of ESWT on ONFH in the future.
In conclusion, ESWT is a new technology and has the potential of replacing surgery in ONFH without the surgical risks. In clinical trials and animal experiments, ESWT stimulates a cascade of signal transduction responses and a series of protein changes to exert its effectiveness in the management of ONFH through neovascularization and regeneration of the bone. Studies to date, however, have involved small numbers with short-term and long-term follow up. A protocol is needed to standardize the optimal timing and dosage of ESWT on ONFH. Further studies are necessary to assess this option in the future.
Disclosure Statement
The authors declared that they did not receive any honoraria or consultancy fees for writing this manuscript. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. One author (Ching-Jen Wang) serves as a member of the advisory committee of SANUWAVE (Suwanee, GA, USA), and this study was performed independent of the appointment. The remaining authors declared no financial conflicts of interest.
References
1Bradway JK, Morrey BF: The natural history of the silent hip in bilateral atraumatic osteonecrosis. J Arthroplasty 1993;8:383–387.
2Zalavras CG, Lieberman JR: Osteonecrosis of the femoral head: evaluation and treatment. J Am Acad Orthop Surg 2014;22:455–464.
3Scaglione M, Fabbri L, Celli F, Casella F, Guido G: Hip replacement in femoral head osteonecrosis: current concepts. Clin Cases Miner Bone Metab 2015;12(Suppl 1):51–54.
4Cao H, Guan H, Lai Y, Qin L, Wang X: Review of various treatment options and potential therapies for osteonecrosis of the femoral head. J Orthop Translat 2016;4:57–70.
5Wang C, Peng J, Lu S: Summary of the various treatments for osteonecrosis of the femoral head by mechanism: A review. Exp Ther Med 2014;8:700–706.
6Hungerford DS: [Role of core decompression as treatment method for ischemic femur head necrosis]. Orthopade 1990;19:219–223.
7Mont MA, Jones LC, Hungerford DS: Nontraumatic osteonecrosis of the femoral head: ten years later. J Bone Joint Surg Am 2006;88:1117–1132.
8Mont MA, Carbone JJ, Fairbank AC: Core decompression versus nonoperative management for osteonecrosis of the hip. Clin Orthop Relat Res 1996;324:169–178.
9Ludwig J, Lauber S, Lauber HJ, Dreisilker U, Raedel R, Hotzinger H: High-energy shock wave treatment of femoral head necrosis in adults. Clin Orthop Relat Res 2001;387:119–126.
10Wang CJ, Wang FS, Huang CC, Yang KD, Weng LH, Huang HY: Treatment for osteonecrosis of the femoral head: comparison of extracorporeal shock waves with core decompression and bone-grafting. J Bone Joint Surg Am 2005;87:2380–2387.
11Vulpiani MC, Vetrano M, Trischitta D, Scarcello L, Chizzi F, Argento G, Saraceni VM, Maffulli N, Ferretti A: Extracorporeal shock wave therapy in early osteonecrosis of the femoral head: prospective clinical study with long-term follow-up. Arch Orthop Trauma Surg 2012;132:499–508.
12Zhang Q, Liu L, Sun W, Gao F, Cheng L, Li Z: Extracorporeal shockwave therapy in osteonecrosis of femoral head: a systematic review of now available clinical evidences. Medicine (Baltimore) 2017;96:e5897.
13Chen JM, Hsu SL, Wong T, Chou WY, Wang CJ, Wang FS: Functional outcomes of bilateral hip necrosis: total hip arthroplasty versus extracorporeal shockwave. Arch Orthop Trauma Surg 2009;129:837–841.
14Kong FR, Liang YJ, Qin SG, Li JJ, Li XL: [Clinical application of extracorporeal shock wave to repair and reconstruct osseous tissue