Extracorporeal Shock Wave Therapy for Plantar Fascial Pain

Transcription

1 Extracorporeal Shock Wave Therapy for Plantar Fascial Pain

2 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 REVIEW Treatment of chronic plantar fasciopathy with extracorporeal shock waves (review) Christoph Schmitz 1*, Nikolaus BM Császár 1, Jan-Dirk Rompe 2, Humberto Chaves 3 and John P Furia 4 Open Access Abstract There is an increasing interest by doctors and patients in extracorporeal shock wave therapy (ESWT) for chronic plantar fasciopathy (PF), particularly in second generation radial extracorporeal shock wave therapy (RSWT). The present review aims at serving this interest by providing a comprehensive overview on physical and medical definitions of shock waves and a detailed assessment of the quality and significance of the randomized clinical trials published on ESWT and RSWT as it is used to treat chronic PF. Both ESWT and RSWT are safe, effective, and technically easy treatments for chronic PF. The main advantages of RSWT over ESWT are the lack of need for any anesthesia during the treatment and the demonstrated long-term treatment success (demonstrated at both 6 and 12 months after the first treatment using RSWT, compared to follow-up intervals of no more than 12 weeks after the first treatment using ESWT). In recent years, a greater understanding of the clinical outcomes in ESWT and RSWT for chronic PF has arisen in relationship not only in the design of studies, but also in procedure, energy level, and shock wave propagation. Either procedure should be considered for patients 18 years of age or older with chronic PF prior to surgical intervention. Keywords: Extracorporeal shock wave treatment (ESWT), Radial extracorporeal shock wave treatment (RSWT), Plantar fasciitis, Plantar fasciopathy Introduction Plantar fasciitis (PF), the most common cause of heel pain, accounts for approximately 11% to 15% of foot symptoms presenting to physicians. In the United States, more than 2 million individuals are treated for PF on an annual basis [1-3]. The term plantar fasciitis implies an inflammatory condition by the suffix itis. However, various lines of evidence indicate that this disorder is better classified as fasciosis or fasciopathy, as heel pain is associated with degenerative changes in the fascia and atrophy of the abductor minimi muscle [1]. When chronic, PF is not an inflammatory condition [1]. The etiology, pathogenesis, associated risk factors, and general treatment strategies for PF have been documented in other comprehensive reviews [1-6]. The condition is usually diagnosed clinically based on the history of morning heel pain made worse with ambulation on hard surfaces and by the physical findings of pain over the medial aspect * Correspondence: christoph_schmitz@med.uni-muenchen.de 1 Department of Anatomy II, Ludwig-Maximilians-University of Munich, Pettenkoferstr. 11, Munich 80336, Germany Full list of author information is available at the end of the article of the plantar fascia. PF has a bimodal distribution, afflicting both athletes and the sedentary. Imaging studies, while generally not needed, can be helpful for ruling out other causes of heel pain or to establish the diagnosis of PF when in doubt. Initial treatment is non-operative and consists of relative rest, physical therapy, stretching, exercises, shoe inserts/ orthotics, night splints, non-steroidal anti-inflammatory drugs, and local corticosteroid injections. Patients not responding to conservative treatment for 4 to 6 months (between 10% and 20% of all patients) are candidates for more aggressive treatment such as extracorporeal shock wave therapy (ESWT) and surgery [1,2]. The safety and efficacy of ESWT for chronic PF has been assessed in a variety of randomized clinical trials (RCTs). Rompe et al. [5] have already reviewed the results of using focused shock wave therapy to treat chronic PF. Since then, five RCTs have assessed the safety and efficacy of radial extracorporeal shock wave therapy (RSWT) for chronic PF [7-11]. Recently, Dizon et al. [12] reviewed the results of using both ESWT and RSWT for chronic PF [12] Schmitz et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

3 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 2 of 11 The following review provides an overview on the physical and medical definitions of shock waves, as well as a detailed assessment of the quality and significance of the recently published RCTs on both ESWT and RSWT for chronic PF. Shock waves Physical definition of shock waves A shock wave is an acoustic pressure wave that is produced in any elastic medium such as air, water, or even a solid substance [13,14]. Shock waves differ from sound waves in that the wave front, where compression takes place, is a region of sudden change in stress and density [13,14]. Because of this, shock waves propagate in a manner different from that of the ordinary acoustic waves. In particular, shock waves travel faster than sound, and their speed increases as the amplitude is raised; however, the intensity of a shock wave also decreases faster than does that of a sound wave because some of the energy of the shock wave is expended to heat the medium in which it travels [13,14]. Accordingly, shock waves are characterized by (1) a high positive peak pressure (P + ), sometimes more than 100 MPa but more often approximately 50 to 80 MPa, (2) a fast initial rise in pressure (T r ) during a period of less than 10 ns, (3) a low tensile amplitude (P, up to 10 MPa), (4) a short life cycle (I) of approximately 10 μs, and (5) a broad frequency spectrum, typically in the range of 16 Hz to 20 MHz [15,16]. The measured shock wave rise time is in the 30-ns range when determined by limited time resolution of the pressure recording hydrophone [15,16]. The positive pressure amplitude is followed by a diffractioninduced tensile wave of a few microseconds duration (Figure 1). Medical definitions of shock waves Extracorporeal shock wave lithotripsy (ESWL) is widely used for stone management in urology. The pressure waves applied in stone management fulfill the characteristics set out by the physical definition of shock waves provided above [17]. The fast initial rise time in pressure and the high positive pressure causes a pressure gradient within the renal calculi that, when of sufficient energy, can fragment the calculi [18]. ESWT and RSWT are by-products of lithotriptor technology. They were introduced into the treatment for various diseases of the musculoskeletal system, such as PF, Achilles tendinopathy, medial tibial stress syndrome, greater trochanteric pain syndrome, lateral and medial epicondylitis, and calcifying tendonitis of the shoulder since the late 1980s [19]. Shock waves have both a direct and indirect effect on treated tissues. The direct effect is the result of the energy of the shock wave being transferred to the targeted tissues. The indirect effect is the result of the production of cavitation bubbles in the treated tissue [13,14]. Both the direct and indirect effects produce a biological response in the treated tissues. Shock wave generators In the United States, the following ESWT/RSWT devices obtained premarket approval (PMA) by the Food and Drug Administration (FDA) as class III orthopedic lithotripsy devices and were reclassified as class III Generators, Shock Wave, For Pain Relief (Product Code NBN) in the Spring 2009: (1) Ossatron (HealthTronics, Inc., Marietta, GA, USA), PMA # P issued on October 12, 2000 to treat chronic heel pain; (2) Epos Ultra (Dornier Medical Systems, Inc., Kennesaw, GA, USA), PMA # P issued on January 15, 2002 for the treatment of chronic plantar fasciitis for patients with symptoms of plantar Figure 1 Pressure as a function of time of a shock wave. P +, positive peak pressure; P, negative peak pressure; T r, rise time (i.e., the time interval during which the positive pressure changes from 10% of P + to 90% of P + ); I +, time interval used to calculate the positive energy of the shock wave; I, time interval to calculate the total energy of the shock wave.

4 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 3 of 11 fasciitis for 6 months or more and a history of unsuccessful conservative therapy; (3) Sonocur Basic (Siemens Medical Solutions, Inc., Iselin, NJ, USA), PMA # P issued on July 19, 2002 for the treatment for pain due to tennis elbow; (4) Orthospec Extracorporeal Shock Wave Therapy (Medispec, Ltd; Germantown, MD, USA), PMA # P issued on April 1, 2005 for the treatment of proximal plantar fasciitis with or without heel spur in patients 18 years of age or older; (5) Orbasone Pain Relief System (Orthometrix, Inc., White Plains, NY, USA), PMA # P issued on August 10, 2005 to relieve heel pain (proximal plantar fasciitis); and (6) Swiss DolorClast (EMS Electro Medical Systems; Dallas, TX, USA), PMA # P issued on May 8, 2007 to treat heel pain associated with chronic proximal plantar fasciitis [20]. The Ossatron, Epos Ultra, Sonocur Basic, and Orbasone devices share the following technical key characteristics of ESWL devices used for stone management: (1) electrohydraulic (OssaTron, Orbasone) or electromagnetic (Epos Ultra, Sonocur) generation of pressure waves and (2) generation of focused pressure waves. The Orthospec device also uses electrohydraulic spark gap technology to generate pressure waves. The Swiss DolorClast generates radial pressure waves ballistically, i.e., by accelerating a bullet to strike an applicator, which transforms the kinetic energy of the bullet into a radially expanding pressure wave [8,21]. It should be noted that studies by Chitnis and Cleveland [22] and Cleveland et al. [23] showed that the Swiss DolorClast does not generate pressure waves that fulfill the characteristics set out by the physical definition of shock waves provided above. Specifically, the rise time of the pressure waves generated by the Swiss DolorClast was reported as 600 [22] or 800 ns [23], respectively. This rise time is approximately 90 times longer than would be expected for a shock wave [23]. Furthermore, the maximum peak positive pressure of the Swiss DolorClast was reported as 5 [22] or 7 MPa [23], respectively. Accordingly, the question has been raised whether the pressure waves generated with the Ossatron, Epos Ultra, Sonocur Basic, Orbasone, and Orthospec devices fulfill the characteristics set out by the physical definition of shock waves provided above. This is addressed in the Appendix. Treatment of chronic plantar fasciopathy with focused shock waves Rompe et al. [5] assessed the quality of all RCTs on focused ESWT for chronic PF that were published in the international peer-reviewed literature until then. To this end, the authors applied evaluation criteria established by Chalmers et al. [24], consisting of two evaluation forms that include 29 individually scored items, allowing a maximum score of 100. Besides this, Rompe et al. [5] used evaluation criteria established by Jadad et al. [25], attributing to each RCT a quality score out of a maximum of six points, addressing the following questions: (1) was the generation of randomization sequence described? (2) was the method of allocation concealment described? (3) was an intention to treat analysis used? (4) what number of patients was lost to follow up? (5) was the outcome assessment blind? and (6) was the patient blind to treatment allocation? This assessment resulted in the following quality scores (see also Table 1): (1) Haake et al. [26], 90 (according to Chalmers et al. [24])/6 (according to Jadad et al. [25]); (2) Kudo et al. [27], 88/6; (3) Malay et al. [28], 84/6; and (4) Buchbinder et al. [29], 82/4. All other RCTs had lower scores and were not classified as good by Rompe et al. [5]; the same holds true for the only RCT on focused ESWT for chronic PF published since then by Gollwitzer et al. [30]. Dizon et al. [12] assessed the same studies using the so-called physiotherapy evidence database (PEDro) scale [31] and ranked them as follows (maximum scale = 11): (1) Kudo et al. [27], Malay et al. [28], and Buchbinder et al. [29], 10; (2) Gollwitzer et al. [30], 9; and (3) Haake et al. [26], 8. Because of the difference between the assessments by Rompe et al. [5] and Dizon et al. [12] and considering that Rompe et al. s [5] assessment criteria are more sensitive than the assessment criteria used by Dizon et al. [12], the latter was no longer considered in this review. Interestingly, Kudo et al. [27] and Malay et al. [28] found statistically significantly (p < 0.05) better outcomes for the patients treated with ESWT than the patients treated with placebo whereas Haake et al. [26] and Buchbinder et al. [29] did not. At first glance, this may be confusing as Haake et al. [26], Kudo et al. [27], and Buchbinder et al. [29] used the same ESWT device (namely, the Epos Ultra). As outlined in the following, however, this discrepancy can be explained by methodological differences between these studies, going beyond the generalized quality criteria for RCTs established by Chalmers et al. [24], Jadad et al. [25], or the PEDro scale [31]. Specifically, application of placebo treatment, patient blinding, and the use of local anesthesia in RCTs with ESWT for chronic PF needs to be addressed (Table 1). Application of placebo treatment and patient blinding The application of placebo treatment in RCTs with ESWT for chronic PF can be achieved in three different ways: (1) treating patients in the placebo group in exactly the same manner as patients in the active group but modifying the shock wave device so that it does not deliver shock waves. This was done in the study by Malay et al. [28] using a foam-insulated contact membrane placed on the applicator that absorbed the shock waves and inhibited transmission of most of the energy but looked identical to an unlined (non-insulated) contact membrane placed on the applicator when treating patients in the active group. (2) Treating

5 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 4 of 11 Table 1 RCTs on ESWT for chronic PF classified as good by Rompe et al. [5] Study Outcome Chalmers score c Jadad score d Placebo treatment L.A. Patients Haake et al. [26] a 90 6 Kudo et al. [27] + b 88 6 Malay et al. [28] + b 84 6 Buchbinder et al. [29] a 82 4 e e + h j a Lack of statistically significantly (p < 0.05) better outcome for the patients treated with ESWT than the patients treated with placebo; b statistically significantly (p < 0.05) better outcome for the patients treated with ESWT than the patients treated with placebo; c quality score according to Chalmers et al. [24]; d quality score according to Jadad et al. [25]; e treatment of patients in the placebo group in exactly the same manner as patients in the active group but placing a foaminsulated or air-filled membrane between the applicator of the shock wave device and the patient s skin that reflects the shock waves; f treatment of patients in the placebo group in exactly the same manner as patients in the active group but modifying the shock wave device so that it does not deliver shock waves; g treatment of patients in the placebo group with only a small number of shock waves at low energy settings; h local anesthesia; i medial calcaneal nerve block anesthesia; j patients with symptoms present for less or more than 6 months who have or have not previously failed pharmacologic (analgesic, anti-inflammatory, or other) and non-pharmacologic treatment modalities for the relief of heel pain; k only patients with symptoms present for more than 6 months who have previously failed pharmacologic (analgesic, anti-inflammatory, or other) and non-pharmacologic treatment modalities for relief of heel pain. f g i k k j patients in the placebo group in exactly the same manner as patients in the active group but placing a foam-insulated or air-filled membrane between the applicator of the shock wave device and the patient s skin that reflects the shock waves. This was done in the studies by Haake et al. [26] and Kudo et al. [27]. (3) Treating patients in the placebo group with only a small number of shock waves at low energy settings. This was applied in the study by Buchbinder et al. [29]. Specifically, Buchbinder et al. [29] treated patients in the placebo group with only 100 impulses with energy flux density (EFD) of 0.02 mj/mm 2 per treatment session, but patients in the active group were treated with 2,000 or 2,500 impulses with EDF varying between 0.02 and 0.33 mj/mm 2 per treatment session. From a methodological point of view, the first option provides the best patient blinding and is the only one in which unblinding of the patients by the ESW therapist can be excluded (provided that the preparation of the device is performed by an independent person, or the ESW therapist is provided with coded active and placebo handpieces; note that in the study by Malay et al. [28], the ESW therapists were not blinded). The second and third options do not keep the ESW therapists unaware of the assigned treatment, opening the possibility that they could be influenced by that knowledge. This requires a strict, standardized way of interaction between the ESW therapist and the patients, irrespective of the treatment allocation (as mentioned in the study by Buchbinder et al. [29]). Moreover, the third option inherits the highest chance of patients unblinding because patients could conclude from the knowledge that is available freely that they were not in the active group. For example, treatment of chronic PF with focused ESWT devices can last for more than 10 min (because the frequency to apply the shock waves using these devices is limited to a few Hz) and can be very painful for the patients if applied without anesthesia (as performed in the study by Buchbinder et al. [29]). However, in the study by Buchbinder et al. [29], the placebo treatment lasted less than 2 min (only 100 impulses applied at a frequency of 1 Hz), whereas the active treatment lasted more than 10 min (2,000 or 2,500 impulses applied at frequencies that were gradually increased to 4 Hz). Thus, in the study by Buchbinder et al. [29], the patients in the placebo group received a painless treatment during a short treatment time, whereas the patients in the active group received a painful treatment during a substantially longer treatment time (note that the active treatment was actually gradually increased through to the highest tolerable level of pain for each participant in this study). Accordingly, the quality of patient blinding (and thus allocation concealment) in the aforementioned studies can be ranked as follows: Malay et al. [28] > Haake et al. [26] = Kudo et al. [27] > Buchbinder et al. [29]. Use of local anesthesia The pain associated with the application of focused shock waves and the need for patient blinding in RCTs testing painful treatment modalities imply that RCTs with ESWT for chronic PF should be performed under local anesthesia (as done by Haake et al. [26]) or nerve block anesthesia (as done by Kudo et al. [27]). However, the application of local anesthesia might contribute to negative outcome of such studies, as demonstrated by Rompe et al. [32]. The molecular mechanisms underlying this phenomenon are not yet fully understood, but substantial evidence points to acentralroleoftheperipheralnervoussysteminmediating molecular and cellular effects of shock waves applied to the musculoskeletal system [33-35]. These effects could be blocked by local anesthesia, as demonstrated in a recent study by Klonschinski et al. [36]. Thus, it is now generally recommended to apply shock waves without local anesthesia to the musculoskeletal system. Kudo et al. [27] did not use local anesthesia, but a medial calcaneal nerve block anesthesia. The authors applied a total of 3,800 impulses in a single session with an average EFD of 0.34 mj/mm 2. In contrast, Malay et al. [28] did not use any anesthesia. These authors applied a

6 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 5 of 11 total of 3,800 impulses in a single session, divided into approximately 540 impulses for each of the seven energy levels of the device used (Orthospec) (resulting in an average EFD of 0.2 mj/mm 2 ). Buchbinder et al. [29] did not use any anesthesia either. The average EFD per impulse in this study (2,000 or 2,500 impulses per treatment session, three treatment sessions, average total EFD = 1, mj/ mm 2 ) was approximately 0.21 mj/mm 2. Accordingly, with respect to the use of local anesthesia, the aforementioned studies can be ranked as follows: Malay et al. [28] = Buchbinder et al. [29] > Kudo et al. [27] > Haake et al. [26]. Significance of published, randomized clinical trials on focused shock wave treatment for chronic plantar fasciopathy Considering the aforementioned methodological issues, the RCTs using focused ESWT for chronic PF that were evaluated as good by Rompe et al. [5] can be assessed as follows. Buchbinder et al. [29] included a total of n =166 patients with symptoms of PF for at least 6 weeks (range 8 to 980 weeks) into their study. Patients in the active group received three sessions of ESWT at weekly intervals, with 2,000 or 2,500 impulses with EFD varying between 0.02 mj/mm 2 and 0.33 mj/mm 2 per treatment session. Patients in the placebo group received only 100 impulses with EFD = 0.02 mj/mm 2 per treatment session. At 6 and 12 weeks, there were significant improvements in overall pain in both the active group and the placebo group. Similar improvements in both groups were also observed for morning and activity pain, walking ability, and other end points. However, there were no statistically significant (p < 0.05) differences in the degree of improvement between the groups for any measured outcomes. It is important to recognize that Buchbinder et al. [29] did not treat chronic PF according to the classic definition of chronic (i.e., patients not responding to conservative treatment for 6 months). Rather, Buchbinder et al. [29] investigated mixed groups of patients suffering from either acute (as short as 8 weeks) or chronic PF. Furthermore, it appears that not all of the patients enrolled by Buchbinder et al. [29] received conservative care before inclusion in the study. For example, only 54% (90/166) of the patients were treated with orthotics before ESWT, only 31% (51/166) received cortisone injections before ESWT, and only 13% (21/166) were treated with physiotherapy before ESWT. Haake et al. [26] treated a total of n = 272 patients with three sessions of 4,000 focused shock waves with EFD = 0.08 mj/mm 2 under local anesthesia or placebo at weekly intervals. After 12 weeks, the success rate was 34% in the ESWT group and 30% in the placebo group; the difference was not statistically significant (p > 0.05). This study was criticized because fewer than half of the enrolled patients received minimal conservative care such as stretching exercises, casting, or night splinting before inclusion in the study (similar to the situation in the study by Buchbinder et al. [29]) [37]. Furthermore, the lack of treatment success in the ESWT group in the study by Haake et al. [26] can be explained by the fact that these authors applied shock waves under local anesthesia. Kudo et al. [27] in a trial of 114 patients with chronic PF, recalcitrant to conservative therapies for at least six months, achieved treatment success by applying focused shock waves (single sessions of 3,800 impulses with EFD = 0.34 mj/mm 2 ) or placebo treatment under medial calcaneal nerve block anesthesia. Good or excellent outcome was reported by 43% of the patients treated with focused shock waves at 12-weeks follow-up and by 30% of the placebo-treated patients (p < 0.05). Kudo et al. [27] did not report the results at longer than 12 weeks after the treatment. Malay et al. [28] included a total of n =172 patients with symptoms present for more than 6 months into their study. Patients must have previously failed two pharmacologic (analgesic, anti-inflammatory, or other) and two non-pharmacologic treatment modalities for the relief of heel pain to be included in the study. Patients were treated with a single session of 3,800 shock waves or placebo, without local anesthesia. The energy flux density of the applied shock waves was continuously increased from 0.08 mj/mm 2 (lowest energy level of the used device) to 0.33 mj/mm 2 (highest energy level of the used device). At 12 weeks, 43% of the patients treated with shock waves and 20% of the patients treated with placebo reported a 50% decrease of pain from baseline (statistically significant, p < 0.05). As with Kudo et al. s [27] trial, Malay et al. [28] did not follow up with the patients longer than 12 weeks after the treatment. In summary, the lack of treatment success in the studies by Buchbinder et al. [29] and Haake et al. [26] using focused ESWT for PF can be explained by serious methodological shortcomings in the corresponding studies. In contrast, the studies by Kudo et al. [27] and Malay et al. [28] demonstrated that chronic PF can be treated successfully with focused shock waves. Furthermore, the study by Malay et al. [28] showed that treatment success can be achieved without any anesthesia. However, long-term (>12 weeks) treatment success has not been demonstrated in either of these trials. Treatment of chronic plantar fasciopathy with radial shock waves Five RCTs have assessed the safety and efficacy of RSWT for chronic PF [7-11]. Two of these studies (Gerdesmeyer et al. [8] and Ibrahim et al. [11]) fulfilled all evaluation

7 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 6 of 11 criteria established by Chalmers et al. [24] and Jadad et al. [25] outlined above. Using the PEDro scale [31], Dizon et al. [12] ranked these studies as follows: (1) Gerdesmeyer et al. [8] and Ibrahim et al. [11], 10; (2) Chow and Cheing [7], 9; and (3) Greve et al. [10], 7. The study by Marks et al. [9] was not considered by Dizon et al. [12]. Furthermore, according to Dizon et al. [12], the therapists were not blinded in the study by Gerdesmeyer et al. [8]. However, this is not correct. Gerdesmeyer et al. s [8] study was a double-blind, randomized, placebo-controlled trial and, thus, should have received a PEDro scale score of 11 in Dizon et al. s [12]assessment. Radial shock waves can be delivered to the tissue without local or nerve block anesthesia, and no form of anesthesia was used in the aforementioned trials. In general, radial extracorporeal shock wave therapy is better tolerated than focused SWT because radial shock waves have their point of highest pressure and highest energy flux density at the tip of the applicator and, thus, outside the tissue. In contrast, focused shock waves have their point of highest pressure and highest energy flux density at the center of their focus which is positioned within the treated tissue. This is demonstrated in Figure 2 showing shadowgraph images of radial and focused shock waves used for the treatment of the musculoskeletal system. Shadowgraph imaging is a visual process that is used to photograph the flow of fluids of varying density. Figure 2A shows radial shock waves generated with the Swiss DolorClast. Note the semicircular wave front and the field of cavitation bubbles surrounded by secondary shock waves above the applicator. The secondary shock waves are produced by rapid collapse of the cavitation bubbles (this process is named inertial cavitation). The cavitation is consequent to the negative phase of the wave propagation. The cavitation field produced with the Swiss DolorClast (15-mm applicator, device operated at 4 bar) has a size of approximately mm (width height). The hydrophone is used to trigger the flash and the camera. Figure 2B shows shock waves generated with a focused shock wave device, Swiss Piezoclast (Electro Medical Systems; the Swiss Piezoclast is currently not FDA approved). Note the convergent waves and the center of the shock wave focus at a height of 4.5 cm above the applicator. Cavitation bubbles appear near the center of the shock wave focus. The picture was generated by mounting five shadowgraph images taken each at 12 μs apart into one figure. The device was operated so that the shock waves had a rise time of 79 ns and a positive peak pressure of 82.8 MPa. Figure 2C shows the cavitation field of the Swiss Piezoclast surrounded by secondary shock waves, observed at 31.6 μs after forming the center of the shock wave focus. The cavitation field has an elliptic shape with equatorial diameter of approximately 2 cm and polar diameter of approximately 5 cm. Note that the so-called Figure 2 Shadowgraph images of radial (A) and focused (B) shock waves (details are provided in the main text). 5-MPa focus (i.e., the region in which the positive pressure exceeds 5 MPa during the positive phase of the wave propagation) of the shock waves generated with the Swiss Piezoclast has an equatorial diameter of 20.8 mm, which equals the equatorial diameter of the cavitation field caused by the shock waves generated with the Swiss Piezoclast. It is of note that the size of the cavitation field depends on

8 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 7 of 11 the medium in which the shadowgraph images are taken. The images shown here were taken in non-degassed water. In contrast, Chitnis and Cleveland [22] investigated the cavitation fields of the Ossatron and Swiss DolorClast devices in degassed water and obtained the following results: Ossatron, mm (width height) and Swiss DolorClast, 3 3 mm (i.e., five times smaller in width and height as demonstrated here). Assuming linear relationships between the results of Chitnis and Cleveland [22] and the findings presented here, one would expect that the cavitation field of the Ossatron device has an equatorial diameter of approximately 50 mm when evaluated in non-degassed water. Interestingly, the 5-MPa focus of the shock waves generated with the Ossatron device has an equatorial diameter of 64 mm, which equals the equatorial diameter of the assumed cavitation field caused by the shock waves generated with this device in non-degassed water. Thus, radial shock waves of a certain energy flux density are generally less painful for and, thus, better tolerated by the patient than the focused shock waves of the same energy flux density. Gerdesmeyer et al. [8] demonstrated safety and efficacy of RSWT with the Swiss DolorClast for chronic PF in a prospective, randomized, double-blinded, placebocontrolled international multicenter study. The authors included a total of n = 245 patients with chronic PF into their study. Inclusion criteria comprised (among others) a history of at least 6 months of chronic plantar painful heel syndrome that proved resistant to non-surgical treatment. Gerdesmeyer et al. [8] administered RSWT or placebo treatment in three sessions, each at 2 weeks (±4 days) apart (2,000 impulses per session, EFD = 0.16 mj/mm 2, eight impulses per second) and evaluated the treatment outcome 12 weeks and 12 months after the first session. The authors found a statistically significant (p <0.05) difference in the reduction of the mean visual analog scale (VAS) composite score between the patients treated with RSWT ( 56.0% ± 39.3%) and the placebo-treated patients ( 44.1% ± 41.8%) at 12 weeks and even more pronounced superiority of RSWT ( 61.9% ± 43.6%) over placebo ( 46.5% ± 45.5%) at 12 months. Ibrahim et al. [11] tested (in a prospective, randomized, double-blinded, placebo-controlled study) the hypothesis that treatment of chronic PF with two RSWT sessions 1 week apart does result in profound pain relief compared to placebo treatment 4 weeks after the first RSWT treatment, lasting for at least 6 months. To test this hypothesis, the authors randomly assigned a total of n = 50 patients with unilateral, chronic PF to either RSWT (n =25) or placebo treatment (n = 25). Inclusion and exclusion criteria were almost identical to those applied by Gerdesmeyer et al. [8]. RSWT was applied in two sessions 1 week apart (2,000 impulses with EFD = 0.16 mj/mm 2 per session). Placebo treatment was performed with a clasp on the heel. End points were changes in the VAS score and the modified Roles and Maudsley (RM) score from baseline to 4-, 12-, and 24-week follow-up. Ibrahim et al. [11] found the mean VAS scores reduced after RSWT from 8.52 ± 0.34 (mean ± SEM) at baseline to 0.64 ± 1.52 at 4 weeks, 1.08 ± 0.28 at 12 weeks, and 0.52 ± 0.14 at 24 weeks from baseline. Similar changes were found for mean RM scores after RSWT but were not observed after placebo treatment. Statistical analysis demonstrated that RSWT resulted in significantly reduced mean VAS scores and mean RM scores at all follow-up intervals compared to placebo treatment (each with p < 0.001). No serious adverse events of RSWT were observed. Ibrahim et al. [11] concluded that RSWT is efficient in the treatment for chronic PF even when only two sessions with 2,000 impulses each are performed 1 week apart. To investigate the dose-effect relationship of RSWT to treatment success, Chow and Cheing [7] randomly assigned a total of n = 57 patients with chronic PF for at least 3 months to three groups. Patients in group A (n = 19, 17 patients completed the trial) received three sessions of RSWT each 1 week apart (1,000 impulses per session, EFD = 0.11 mj/mm 2, three impulses per second). Patients in group B (n = 19, 18 patients completed the trial) were treated in the same manner but with increasing energy flux densities (first week, EFD = 0.12 mj/mm 2 ; second week, EFD = 0.15 mj/mm 2 ; third week, EFD = 0.17 mj/mm 2 ). Patients in group C served as control (n = 19, 14 patients completed the trial; three sessions of RSWT each 1 week apart, 30 impulses per session, EFD = 0.03 mj/mm 2, three impulses per second). Six weeks after the first RSWT session, patients in groups A and B showed (among other variables) statistically significant (p < 0.05) reductions in mean VAS scores by 37% (group A) and 83% (group B), respectively, compared to the baseline. By contrast, patients in group C showed no changes in mean VAS scores compared to the baseline. The results of the patients in group B of the study by Chow and Cheing [7] were consistent with the results reported by Gerdesmeyer et al. [8] and Ibrahim et al. [11], indicating that the energy flux density of the applied radial shock waves must exceed a certain level in order to cause a therapeutic effect. Other trials investigating the use of RSWT to treat chronic PF have yielded negative outcomes. Marks et al. [9] enrolled 25 adult patients with chronic PF in their study. The authors randomly assigned 16 patients to RSWT (three sessions each 3 days apart, 500 impulses in the first session and 2,000 impulses in the second and third session, respectively; EFD = 0.16 mj/mm 2,frequencyoftheimpulses not provided). Another nine patients were placebo treated (i.e., in the same manner as the patients subjected to RSWT but with the energy flux density of the radial shock waves reduced to almost zero). Of the patients,

9 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 8 of % (9/16) that were treated with RSWT and 44.4% (4/9) of the patients treated with placebo reported (compared to baseline) a reduction in the VAS score greater than 50%, 6 months after the first session (defined as treatment success by the authors). This difference was not statistically significant (p > 0.05). However, the total mean VAS score of the patients treated with RSWT was reduced by 54.1% at 6-month follow-up but the total mean VAS score of the patients treated with placebo only by 3.9%. Marks et al. [9] concluded that there appeared to be a profound placebo effect in patients with heel pain, as well as a lack of evidence for the efficacy of RSWT in treating PF compared to sham therapy. The paper by Marks et al. [9] has some weaknesses: (1) in the main text, the authors described an average duration of heel pain of 28.3 months before RSWT or sham treatment. On the other hand, the duration of symptoms was reported in Table 1 of the same paper as follows: 35.6 ± 43.2 days (mean ± standard deviation) (range, 1 to 180 days) for the patients treated with RSWT and 21.0 ± 16.4 days (range, 1 to 60 days) for the patients treated with placebo. As was true in the trial by Buchbinder et al. [29], Marks et al. [9] investigated mixed groups of patients suffering from either acute or chronic PF. Since more than 80% of PF patients experience resolution within 12 months, regardless of management [1], the approach by Marks et al. [9] could be considered an inadequate selection of PF patients for RSWT rather than reflecting inefficacy of RSWT treatment for this disease (similar to the study by Buchbinder et al. [29] discussed above). (2) This is further corroborated by the notion that at least one patient treated with placebo had a VAS score of 6 (with a maximum VAS score of 100) in the study by Marks et al. [9], which would translate into a VAS score of 0.6 in the studies by Chow and Cheing [7], Gerdesmeyer et al. [8], and Ibrahim et al. [11]. It remains unknown why such almost pain-free patients were enrolled in the study by Marks et al. [9]. Greve et al. [10] reported the results of 16 patients with chronic PF treated with RSWT (three sessions each 7 days apart, 2,000 impulses per session; EFD = 0.14 mj/mm 2, six impulses per second, group A), and another n =16 patients with chronic PF to conventional physiotherapy (ten sessions of ultrasound, two sessions per week, plus exercises, group B). The authors found that both treatments were effective for pain reduction and improving the functional abilities of patients with PF (treatment success was not calculated as in the studies by Gerdesmeyer et al. [8], Marks et al. [9], and Ibrahim et al. [11]). However, the authors noted that the effects of RSWT occurred sooner than physiotherapy after the onset of treatment. In summary, the lack of treatment success in the study by Marks et al. [9] using RSWT for PF can be explained by serious methodological shortcomings in this study (as in the case of the studies by Haake et al. [26] and Buchbinder et al. [29] on focused ESWT for chronic PF discussed above). In contrast, the studies by Chow and Cheing [7], Gerdesmeyer et al. [8], Greve et al. [10], and Ibrahim et al. [11] demonstrated that chronic PF can be treated successfully with RSWT. Most importantly, RSWT for chronic PF was demonstrated to result in long-term treatment success, demonstrated at both 6 [11] and 12 months [8] after the first treatment. These results justify the general recommendation to offer RSWT to patients 18 years of age or older with symptoms of PF for 6 months or more and a history of unsuccessful conservative therapy, before considering any surgical treatment. ESWT/RSWT vs. surgery in the treatment of chronic plantar fasciopathy ESWT and RSWT have several advantages over surgery in the treatment for chronic PF, including minimally invasive percutaneous radio frequency nerve ablation propagated recently [38-42]. Because RSWT does not require local anesthesia, the procedure is completely non-invasive. In contrast, surgery has risks such as transient swelling of the heel pad, injury of the posterior tibial nerve or its branches, and flattening of the longitudinal arch with resultant midtarsal pain. In contrast to surgery, either open or endoscopic, ESWT and RSWT do not require patients to avoid weight bearing or a prolonged time for return to work. Rather, ESWT and RSWT allow patients to return to activities of daily life within 1 or 2 days, with an immediate return to most jobs and normal daily shoe wear. Conclusions Both ESWT with focused shock waves and second generation RSWT are safe, effective, and easy treatments for chronic PF not responding to conservative therapy. Efficacy and safety of both ESWT and RSWT for chronic PF have been demonstrated in several RCTs in the international peer-reviewed literature. The lack of treatment success in some published RCTs using ESWT or RSWT can be explained by serious methodological shortcomings in the corresponding studies rather than reflecting inefficacy of ESWT or RSWT for this disease. Unlike surgery, ESWT and RSWT are non-invasive and can be performed as in office procedures, without the use of anesthesia. Furthermore, ESWT and RSWT do not require patients to avoid weight bearing or a prolonged time for return to work. The main advantages of RSWT over first generation focused ESWT are the lack of need for any anesthesia during the treatment and the demonstrated long-term treatment success (demonstratedatboth6 and 12 months after the first treatment using RSWT,

10 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 9 of 11 compared to follow-up intervals of no more than 12 weeks after the first treatment using ESWT). Appendix This appendix addresses the question whether the pressure waves generated with the Ossatron, Epos Ultra, Sonocur Basic, Orbasone, and Orthospec devices fulfill the characteristics set out by the following physical definition of shock waves [15,16]: (1) a high positive peak pressure (P + ), sometimes more than 100 MPa but more often approximately 50 to 80 MPa, (2) a fast initial rise in pressure (T r ) during a period of less than 10 ns, (3) a low tensile amplitude (P, up to 10 MPa), (4) a short life cycle (I) of approximately 10 μs, and (5) a broad frequency spectrum, typically in the range of 16 Hz to 20 MHz. This question can be answered as follows: (1) the rise times of the pressure waves generated with the Sonocur Basic and Orbasone devices have not been published. Accordingly, it cannot be decided whether the pressure waves generated with these devices fulfill the characteristics set out by the physical definition of shock waves provided above. (2) The pressure waves generated with the Ossatron device were reported to have a rise time of 38 ns and a maximum peak positive pressure of 37.7 MPa [22,23]. Chitnis and Cleveland [22] characterized these pressure waves as shock waves. (3) The pressure waves generated with the Orthospec device were reported to have a rise time of 400 ± 100 ns and a maximum peak positive pressure of 34 ± 13 MPa [43]. Accordingly, the pressure waves generated with the Orthospec device are not shock waves according to the physical definition provided above. (4) Haake et al. [26] and Buchbinder et al. [29] treated patients suffering from PF with pressure waves generated with the Epos Ultra device. Buchbinder et al. [29] used various energy settings, i.e., within levels 1 to 9 (treatment began on level 1 and was gradually increased through to the highest tolerable level of pain for each participant). In contrast, Haake et al. [26] applied pressure waves with an EFD of 0.08 mj/mm 2 (i.e., level 3). The rise time of the pressure waves generated with the Epos Ultra device is approximately 600 ns at level 1, approximately 500 ns at level 3, approximately 200 ns at level 7, and less than 100 ns at level 9 (EMS Electro Medical Systems, Nyon, Switzerland; unpublished data). Furthermore, the positive peak pressure of the pressure waves generated with the Epos Ultra device is less than 7.5 MPa at level 1, less than 20 MPa at level 3, approximately 36 MPa at level 7, and approximately 56 MPa at level 9 (EMS Electro Medical Systems, Nyon, Switzerland; unpublished data). Accordingly, the pressure waves generated with the Epos Ultra device applied by Haake et al. [26] were not shock waves according to the physical definition provided above. The same holds true for the pressure waves generated with the Epos Ultra device at levels 1 to 7 applied by Buchbinder et al. [29]. This is in line with Cleveland et al. s [23]notionthatfor treatment protocols at low energy settings, electromagnetic ESWT devices (such as the Epos Ultra) will not produce shock waves. Accordingly, the pressure waves generated with the Orthospec device, as well as the Epos Ultra device operated at levels 1 to 7, do not fulfill the characteristics set out by the physical definition of shock waves provided above. Nevertheless, the pressure waves generated with these devices are named shock waves in the international peer-reviewed literature [26,28,29]. The same holds true for the pressure waves generated with the Ossatron device [22]. This indicates that in the field of musculoskeletal applications of pressure waves, several definitions of shock waves are used, irrespective of the type of generation or focusing of these pressure waves. This is also illustrated by the following characterization of shock waves applied to the musculoskeletal system by Rompe et al. [5]: (1) rise time < 1 μs and (2) positive peak pressure between 10 and 100 MPa (note that the pressure waves generated with the Swiss DolorClast have a positive peak pressure of more than 10 MPa when measured at 1 mm distance to the applicator. Chitnis and Cleveland [22] and Cleveland et al. [23] performed their measurements at 10 mm distance to the applicator). Thus, the difference between the Ossatron, Epos Ultra, Sonocur Basic, Orbasone, and Orthospec devices on one hand, and the Swiss DolorClast, on the other hand, is not that the former devices produce shock waves and the latter one does not. Rather, the former devices generate focused pressure waves, whereas the latter one produces unfocused pressure waves, and both are Table 2 Characteristics of the pressure waves generated with various ESWT/RSWT devices marketed in the United States Wave characteristics Devices generating focused shock waves Devices generating radial shock waves Pressure waves that fulfill the characteristics set out by the physical definition of shock waves below a Ossatron (SONOCUR Basic) b and (Orbasone) b Pressure waves that do not fulfil the characteristics Orthospec and Epos Ultra c Swiss DolorClast set out by the physical definition of shock waves below a The names of the corresponding manufacturers are provided in the main text. a Physical definition of shock waves [15,16]: (1) a high positive peak pressure (P + ), sometimes more than 100 MPa but more often approximately 50 to 80 MPa, (2) a fast initial rise in pressure (T r ) during a period of less than 10 ns, (3) a low tensile amplitude (P, up to 10 MPa), (4) a short life cycle (I) of approximately 10 μs, and (5) a broad frequency spectrum, typically in the range of 16 Hz to 20 MHz; b rise time not published; c when operated at levels 1 to 7 (i.e., as in clinical use for treatment of PF [26,29]).

11 Schmitz et al. Journal of Orthopaedic Surgery and Research 2013, 8:31 Page 10 of 11 named shock waves in the international peer-reviewed literature (Table 2). It is important to note that the usability of shock waves for the treatment of the musculoskeletal system does not depend on whether these waves are shock waves according to the physical definition provided above or not. Rather, a significant tissue effect of these shock waves is cavitation consequent to the negative phase of the wave propagation [15]. Specifically, Schelling et al. [44] demonstrated stimulation of nerves with shock waves indirectly, i.e., via a cavitation-mediated mechanism. Nerve stimulation is nowadays hypothesized being a central mechanism of action of ESWT/RSWT for the musculoskeletal system [33-35]. As shown by Chitnis and Cleveland [22], both the Ossatron device (generating focused shock waves that fulfill the characteristics set out by the physical definition of shock waves provided above) and the Swiss DolorClast (generating radial shock waves that do not fulfill the characteristics set out by the physical definition of shock waves provided above) can induce cavitation (see also Figure 2). Competing interests CS serves as paid consultant for and receives benefits from Electro Medical Systems S.A. (Nyon, Switzerland), the manufacturer and distributor of the Swiss DolorClast radial shock wave device. Accordingly, CS has received benefits for personal use from a commercial party related directly or indirectly to the subject of this article. However, CS, NC, JDR, HC, and JF declare that they have not received any honoraria or consultancy fee in writing this manuscript. No benefit was received or will be received directly or indirectly from a commercial party related to the performance of this study. Authors contributions CS, NC, JDR, HC, and JF drafted the protocol of this study, searched references, collected data, performed data analysis, and helped in drafting the manuscript. All authors read and approved the final manuscript. Acknowledgement This work is dedicated to Mr. Rocco DePace and his dedicated effort in promoting radial extracorporeal shock wave therapy during the last decade in the US. Rocco died on June 5, 2012 at age 41. Author details 1 Department of Anatomy II, Ludwig-Maximilians-University of Munich, Pettenkoferstr. 11, Munich 80336, Germany. 2 OrthoTrauma Evaluation Center, Oppenheimer Str. 70, Mainz 55130, Germany. 3 Institute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, Lampadiusstr. 4, Freiberg 09596, Germany. 4 Sun Orthopaedic Group, Inc., 900 Buffalo Rd., Lewisburg, PA 17837, USA. Received: 26 June 2013 Accepted: 27 August 2013 Published: 3 September 2013 References 1. Rompe JD: Plantar fasciopathy. Sports Med Arthrosc 2009, 17: Thomas JL, Christensen JC, Kravitz SR, Mendicino RW, Schuberth JM, Vanore JV, Weil LS Sr, Zlotoff HJ, Bouché R, Baker J, American College of Foot and Ankle Surgeons heel pain committee: The diagnosis and treatment of heel pain. a clinical practice guideline-revision J Foot Ankle Surg 2010, 49:S1 S Tong KB, Furia J: Economic burden of plantar fasciitis treatment in the United States. Am J Orthop 2010, 39: Furia JP, Rompe JD: Extracorporeal shock wave therapy in the treatment of chronic plantar fasciitis and Achilles tendinopathy. Curr Opin Orthop 2007, 18: Rompe JD, Furia J, Weil L, Maffulli N: Shock wave therapy for chronic plantar fasciopathy. Br Med Bull 2007, 81 82: Neufeld SK, Cerrato R: Plantar fasciitis: evaluation and treatment. J Am Acad Orthop Surg 2008, 16: Chow IH, Cheing GL: Comparison of different energy densities of extracorporeal shock wave therapy (ESWT) for the management of chronic heel pain. Clin Rehabil 2007, 21: Gerdesmeyer L, Frey C, Vester J, Maier M, Weil L Jr, Weil L Sr, Russlies M, Stienstra J, Scurran B, Fedder K, Diehl P, Lohrer H, Henne M, Gollwitzer H: Radial extracorporeal shock wave therapy is safe and effective in the treatment of chronic recalcitrant plantar fasciitis: results of a confirmatory randomized placebo-controlled multicenter study. Am J Sports Med 2008, 36: Marks W, Jackiewicz A, Witkowski Z, Kot J, Deja W, Lasek J: Extracorporeal shock-wave therapy (ESWT) with a new-generation pneumatic device in the treatment of heel pain: a double blind randomised controlled trial. Acta Orthop Belg 2008, 74: Greve JM, Grecco MV, Santos-Silva PR: Comparison of radial shockwaves and conventional physiotherapy for treating plantar fasciitis. Clinics 2009, 64: Ibrahim MI, Donatelli RA, Schmitz C, Hellman MA, Buxbaum F: Chronic plantar fasciitis treated with two sessions of radial extracorporeal shock wave therapy. Foot Ankle Int 2010, 31: Dizon JN, Gonzalez-Suarez C, Zamora MT, Gambito ED: Effectiveness of extracorporeal shock wave therapy in chronic plantar fasciitis: a metaanalysis. Am J Phys Med Rehabil 2013, 92: Ueberle F: Shock wave technology. In Extracorporeal Shock Waves in Orthopaedics. 1st edition. Edited by Siebert W, Buch M. Berlin: Springer; 1998: Ueberle F: Einsatz von Stoßwellen in der medizin [Application of shock waves in medicine]. In Medizintechnik. 1st edition. Edited by Kramme R. Berlin: Springer; 2007: Ogden JA, Tóth-Kischkat A, Schultheiss R: Principles of shock wave therapy. Clin Orthop Rel Res 2001, 387: Schleberger R, Delius M, Dahmen GP, Diesch R, Schaden W, Thiele R, Vogel J: Orthopaedic extracorporeal shock wave therapy (ESWT): method analysis and suggestion of a prospective study design - consensus report. In High Energy Shock Waves in Medicine. 1st edition. Edited by Chaussy C, Eisenberger F, Jocham D, Wilbert D. Stuttgart: Thieme; 1997: Rassweiler JJ, Knoll T, Köhrmann KU, McAteer JA, Lingeman JE, Cleveland RO, Bailey MR, Chaussy C: Shock wave technology and application: an update. Eur Urol 2011, 59: Zhong P, Preminger GM: Mechanisms of differing stone fragility in extracorporeal shockwave lithotripsy. J Endourol 1994, 8: Gerdesmeyer L, Weil LS: Extracorporeal Shock Wave Therapy: Technologies, Basics, Clinical Results. 1st edition. Data Trace Media: Brooklandville; Csaszar NBM, Schmitz C: Extracorporeal shock wave therapy in musculoskeletal disorders. 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12 Hindawi Publishing Corporation BioMed Research International Volume 2016, Article ID , 8 pages Clinical Study Success and Recurrence Rate after Radial Extracorporeal Shock Wave Therapy for Plantar Fasciopathy: A Retrospective Study Nikos Malliaropoulos, 1,2,3,4 Georgina Crate, 5 Maria Meke, 1,2 Vasileios Korakakis, 6,7 Tanja Nauck, 8 Heinz Lohrer, 3,8,9 and Nat Padhiar 3,4 1 Sports and Exercise Medicine Clinic, Asklipiou 17, Thessaloniki, Greece 2 National Track and Field Centre, Sports Medicine Clinic of S.E.G.A.S., Thessaloniki, Greece 3 European Sports Care, 68 Harley Street, London W1G 7HE, UK 4 Centre for Sports & Exercise Medicine, Queen Mary University of London, Bancroft Road, London E1 4DG, UK 5 King s College London Medical School, London SE1 1UL, UK 6 Aspetar Orthopaedic and Sports Medicine Hospital, P.O. Box 29222, Doha, Qatar 7 Faculty of Sport Science and Physical Education, University of Thessaly, Karyes, Trikala, Greece 8 European Sportscare Network (ESN), Zentrum für Sportorthopädie, Borsigstrasse 2, Wiesbaden-Nordenstadt, Germany 9 Institute for Sport and Sport Sciences, Albert-Ludwigs-Universität Freiburg im Breisgau, Schwarzwaldstraße 175, Freiburg, Germany Correspondence should be addressed to Georgina Crate; georginacrate@doctors.org.uk Received 18 December 2015; Revised 10 April 2016; Accepted 19 April 2016 Academic Editor: Vinod Chandran Copyright 2016 Nikos Malliaropoulos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background and Aims. The exploration of an individualised protocol of radial extracorporeal shock wave therapy (reswt) for plantar fasciopathy, assessing success rates and the recurrence rate over a 1-year period after treatment, is not yet identified in literature. Methods and Results. Between 2006 and 2013, 68 patients (78 heels) were assessed for plantar fasciopathy. An individualised reswt treatment protocol was applied and retrospectively analysed. Heels were analysed for mean number of shock wave impulses, mean pressure, and mean frequency applied. Significant mean pain reductions were assessed through Visual Analogue Scale (VAS) after 1-month, 3-month, and 1-year follow-up. Success rates were estimated as the percentage of patients having more than 60% VAS pain decrease at each follow-up. 1-year recurrence rate was estimated. The mean VAS score before treatment at 6.9 reduced to 3.6, 1 month after the last session, and to 2.2 and 0.9, after 3 months and 1 year, respectively. Success rates were estimated at 19% (1 month), 70% (3 months), and 98% (1 year). The 1-year recurrence rate was 8%. Moderate positive Spearman s rho correlation (r =0.462, p<0.001) was found between pretreatment pain duration and the total number of reswt sessions applied. Conclusions. Individualised reswt protocol constitutes a suitable treatment for patients undergoing reswt for plantar fasciitis. 1. Introduction Plantar fasciopathy (PF) is a common cause of heel pain and many treatment options are available [1]. The plantar fascia is abandofconnectivetissuethatsupportsthearchesofthe foot [2], specifically the longitudinal arch, and provides shock absorbance for the foot [3]. PF is an enthesopathy of the proximal insertion of the band [4], resulting in heel pain that is classically worse on starting activity or in the morning [3]. PF is frequently self-limiting. There are certain factors that can predispose to its development. Risk factors usually reported in the literature as leading to an increased risk of PF include high body mass index or anatomical abnormalities such as pes cavus or leg length discrepancy [5 7]. Prolonged standing and reduced ankle dorsiflexion have also been shown to influence the development of PF [8]. There are many treatment options available for PF, ranging from the conservative stretching and orthotics to the

13 2 BioMed Research International more invasive injections and, in recalcitrant cases, surgery [4]. ESWT is an alternative treatment modality that has been shown to be of benefit for PF since the 1990s [9]. Shock waves are purported to produce a controlled injury to the area resulting in neovascularisation and hence promoting healing by increasing growth factors locally [10]. Therefore, it has been proposed that ESWT is provided to patients suffering from chronic PF unresponsive to other conservative treatments [11 13]. ESWT has been shown to be beneficial for many conditions, including Achilles tendinopathy, medial tibial stress syndrome, and calcific tendinitis of the shoulder [14 16]. ESWT can be separated into two different types, radial and focused. With regard to focused extracorporeal shock wave therapy (feswt) the waves are targeted specifically onto the affected area, whereas the waves produced by radial extracorporeal shock wave therapy (reswt) do not concentrate on the area but instead disperse to the surrounding tissue too [17]. reswt has been found to be of possibly more benefit than feswt because the treatment area is larger [17], which is more beneficial for superficial injuries such as tendinopathies [18]. However there are studies that do argue for the use of feswt over reswt [19] or report no difference in terms of effectiveness [20]. PF is said to produce pain in a certain area rather than in a particular spot; therefore reswt may tackle the condition better than feswt [18]. Some studies do not provide follow-up data up to a year or more after treatment, which would help support or dismiss reswt as a viable treatment option [18, 21]. Moreover, many studies do not specify whether reswt or feswt was applied [21 23]. This results in some confusion over the data. Recurrence rates for patients with PF treated with reswt are also not well recorded in the literature. Often, there are no recurrence rates given for those who were initially treated successfully but then suffered a relapse of symptoms later on. The aim of this study was to report the protocol used and the recurrence rate of PF after a flexible/individualised treatment with reswt. The hypothesis (H 0 )thatthereis no relationship between pretreatment pain duration and the number of reswt treatment sessions applied was also stated. 2. Methods and Materials 2.1. Participants. Seventy-four adults were sequentially diagnosed with PF (11 bilateral patients and 63 unilateral patients) and consented after having visited a sport and exercise medicine clinic between 2006 and All patients had a comprehensive history taken and clinical examination performed. Examination includes observation for any swelling and palpating the anatomical site of pain. This is to exclude partial plantar fascia tear (which usually occurs approximately 1.5 cm distal from the medial portion attachment), stress fracture of the calcaneus, and medial calcaneal nerve entrapment. The other useful examination is percussing (Tinel test) the inferior aspect of medial malleolus to look for tarsal tunnel syndrome [24]. Ultrasound scanning (USS) was performed in all cases in the clinic by the specialist sports medicine physician to firstly confirm the diagnosis of PF but also to review the anatomy. USS provides information on Table 1: Characteristics of the patients. Characteristic Patients Gender Male (%) 29 (42.6%) Female (%) 39 (57.4%) Foot affected Right (%) 26 (38.2%) Left (%) 32 (47.1%) Bilateral (%) 10 (14.7%) Age (years) mean (SD) (±11.29) Duration of pretreatment pain (months) mean (SD) (±59.3) Values are counts (number of patients) (percentages) unless stated otherwise. soft tissue abnormalities (e.g., synovial cysts and soft tissue induration due to fat pad contusion) but primarily allows assessment of the thickness of the plantar fascia, presence of any neovascularisation, and obvious or subtle plantar fascia tears [25]. Exclusion criteria were as follows: less than eighteen years of age, those who had undergone surgery for PF, any history of malignancy, a history of radicular back pain, any fractures in the foot, ankle, and tibia, and previous ESWT treatment. Sixty-eight individuals (58 unilateral patients and 10 bilateral patients) were finally retrospectively analysed, 29 males (43%) and 39 females (57%) whose age ranged from 18 to 75 years with an average age of 47±11 years. PF emergence differentiated in means of pain duration experienced by patients until the initialization of the treatment. We found that 21 patients (31%) experienced pain for less than three months, 14 patients (21%) experienced pain from three to six months, 18 patients (26%) experienced pain from six to 12 months, six patients experienced pain from 12 to 24 (9%) months, and nine patients (13%) experienced pain more than 24 months (Table 1) Treatment Modalities. Ultrasound gel was applied to the affected area. The reswt machine used was the Storz Medical Masterpuls MP 200 (Storz Medical, Tägerwilen, Switzerland). Application of reswt was performed by a trained physiotherapist. Patients were treated with an individualised protocol also dependent on their tolerance to treatment. The number of sessions, the number of impulses, the pressure, and the frequency varied between the subjects depending on the healing process and the severity and insistence of symptoms. The protocols were analysed retrospectively. However, all patients were treated for a minimum of four to six sessions. Six to eight sessions were recommended if pain existed for more than three months. One treatment was performed per week. The working pressure was influenced by the patient s pain tolerance. If the patient was unable to cope with the set pressure due to pain, then the pressure was lowered until found acceptable by the patient. Therefore, the higher the degree of pain, the lower the pressure, although it was always set at a minimum of 1 bar.

14 BioMed Research International 3 Eligibility 6 dropped out Treatment Diagnosed and included n=74 Heels = 85 reswt treated n=68 Heels = 78 Baseline VAS Follow-up 1 1 month Success rate n=67,heels= 77, missed =1 Retrospective Follow-up 2 3 months Follow-up 3 1 year Success rate n=67,heels= 77, missed =0 Success rate n=64,heels= 74, missed =3 reswt Mean impulses Mean pressure (bar) Mean frequency (Hz) Heels = 78 Recurrence? Number of sessions Heels = 78 Duration of heel pain in months before treatment Figure 1: Flowchart of the research study stages. Unidirectional arrows indicate the sequential stages of the study; bidirectional arrows indicate that correlation between variables was examined Evaluation and Follow-Up. The effects of the reswt were evaluated in all 68 patients (78 heels) over a period of one year via follow-ups arranged at 1 month, 3 months, and 1 year after treatment. Patients recorded the level of pain felt through the Visual Analogue Score (VAS) selfevaluation tool, after viewing a straight line separated in equal intervals of 1 cm, ranging from 0 to 10, where 0 represents no pain and 10 worst imaginable pain [26]. VAS scores were assessed to compute both mean VAS reductions and success rates. One-year follow-up for any recurrence of symptoms was assessed during a clinic appointment. Recurrence of symptoms was defined as a painful event requiring additional cycles of treatment, or anyone with a one-year follow-up VAS score over and including four (Figure 1) Statistical Analysis. The statistical analysis was performed using Microsoft Excel and SPSS 20. The frequency of the number of reswt sessions was assessed, as well as mean shock wave impulses, mean pressure, and mean frequency applied. It was also tested as to whether the pretreatment VAS scores (baseline) were statistically significantly different from the posttreatment VAS scores with Wilcoxon Signed Ranks Test and Monte Carlo simulation to test statistical significance [27 29]. Success rates were assessed as the percentage of those having more than 60% VAS pain decrease from baseline scores [18]. Mean VAS reduction in each follow-up time interval was estimated according to the percentage of mean pain level reductions (difference in VAS scores) recorded in each follow-up time interval. In addition, mean VAS reductions were determined by dividing the difference of mean VAS pain scores by the mean VAS pain score at baseline. The percentage of VAS pain scores decrease is actually coarse metrics since they do not provide evidence about the reasons of pain healing or the significance. Recurrence rate was assessed and Spearman s rho correlation was performed in order to test if there are grounds of approving a relationship between pain duration and the number of reswt sessions needed. The confidence level was set at 95% (α =0.05)forallstatisticaltestsperformed. 3. Results From the initial number of patients included, 6 patients (5 unilateral and 1 bilateral) dropped out of the study group in the very early sessions due to financial or transportation issues, not because of the treatment itself. There were no adverse effects reported by the patients. The number of reswt sessions per patient ranged from 4 to 11 with a mean of 7±1.6.Atotalofseventy-eight(78)heels were treated with an average of 2000 impulses per session at ameanpressureof1.7 ± 0.2 bar (ranged from 1.3 to 2.2) and a mean frequency of 5±0.2Hz (ranged from 5 to 6) (Figure 2). From the total of 68 patients, 9 (13%) received 4 sessions, 10 (15%) received 5 sessions, 21 (31%) received 6 sessions, 5 (7%) received 7 sessions, 17 (25%) received 8 sessions, 2 (3%) received 9 sessions, 3 (4%) received 10 sessions, and 1 (1%) received 11 sessions. There was significant reduction in VAS pain score between baseline and 1-month follow-up (z = 7.809, p= 0.000), between baseline and 3-month follow-up (z = 7.770,

15 4 BioMed Research International Table 2: VAS means, SD, and median. N (feet) Mean SD Min Max Percentiles 25th 50th (median) 75th Baseline VAS VAS 1 month after treatment VAS 3 months after treatment VAS 12 months after treatment Shock wave impulses (±80) (±92) (±101) 2028 (±117) (±149) (±136) (±222) (±229) 2167 (±408) 2250 (±500) Pressure/frequency st session 2nd session 3rd session 4th session 5th session 6th session 7th session 8th session 9th session 10th session 11th session (n = 78) (n = 78) (n = 78) (n = 78) (n = 67) (n = 57) (n = 34) (n = 28) (n = 6) (n = 4) (n = 1) Mean impulses Mean pressure Mean frequency Number of session 0.0 Figure 2: Heels reswt mean impulses, mean pressure (bar), mean frequency (Hz), and number of patients contributing to each successive session. p=0.000), and between baseline and 1-year follow-up (z = 7.615, p = 0.000). 3 patients did not contribute in the 1- year VAS follow-up and recurrence examination (Table 2). Negative ranks were recorded in all cases and the mean rank was found 39 at 1-month follow-up, 39 at 3-month follow-up, and 37.5 at 12-month follow-up. VAS rating was 7 at baseline, 4at1monthaftertreatment,2at3monthsaftertreatment, and 1 at 12 months after treatment. The average pain level before treatment was 6.9 and it was reduced to 3.6 one month after the last reswt session and to 2.2 and 1.0 after 3 months and 1 year, respectively. The mean VAS reduction was 48% 1 month after treatment and 68% and 86% after 3-month and 1-year follow-up (Figure 3). Success rates were calculated at 19% (15 heels) at 1 month after treatment, at 70% (54 heels) at 3 months after treatment, and 98% (73 heels) at 1 year after treatment. The recurrence rate was 8% (5 patients out of 65) in 1-year follow-up. Spearman s rho correlation was positive and moderate [30] between pre-reswt treatment pain duration and the number of sessions applied (r = 0.462, p = 0.000). One year after treatment VAS was also significantly correlated with pretreatment pain duration (r = 0.561, p = 0.000) and with the number of reswt sessions (r =0.712, p=0.000) performed. A positive Spearman s rho correlation was found in both cases, moderate and strong, respectively. The Mann-Whitney U test was used to assess continuous variables between the group of patients with or without pain recurrence and Monte Carlo simulation to test statistical significance. The recurrence rate was 8% accounting for 6 heels from the 74 assessed at the one-year follow-up (5 out of 65 patients). Specifically, there was one male patient with unilateral recurrence (1.4% of the feet) and four (three unilateral and one bilateral) female patients (6.8% of the feet) (Table 3).

16 BioMed Research International 5 Table 3: Patients characteristics based on recurrence. Variable Recurrence N (feet) Mean SD Min Max Median Mean rank Age No (recurrence) Yes (recurrence) Pretreatment pain duration (months) No (recurrence) Yes (recurrence) Total number of reswt sessions No (recurrence) Yes (recurrence) Baseline VAS No (recurrence) Yes (recurrence) One-year follow-up VAS No (recurrence) Yes (recurrence) % % % 70% 70 VAS % Percentage (%) 2 19% Pretreatment 1 month 3 months 12 months Follow-up time intervals 0 % VAS reduction from baseline Success rate Average pain level (1 10 VAS) Figure 3: reswt mean VAS reduction, success rate, and average pain level over 1-year follow-up intervals. Statistically significantly differences between the recurrence and the nonrecurrence group were found in pretreatment pain duration (U =46, p<0.001), in the total number of reswt sessions applied (U = 97, p = 0.029), and in baseline VAS score (U =74, p=0.006). 4. Discussion reswt has already been acknowledged as an effective treatment for PF in previous studies but never in the context of an individualised protocol as regards the sessions applied, impulses, pressure, and frequency depending on each individual patient tolerance and response to treatment. The proposed treatment modality herein showed a 47% mean VAS reduction at 1 month, 68% at 3 months, and 86% at 1 year from the baseline, indicating good short-term and longterm results. One-year success rate at 98% revealed excellent response of patients to a modifiable reswt treatment and the recurrence rate at 1 year was only 8%. A serious consideration arises though when ESWT s results and its role in treating PF are compared between different published studies. A contributing factor for this is the lack of reporting as to whether feswt or reswt is being used. Furthermore, the current guidelines for the treatment of planar fasciitis offered by the National Institute for Health and Care Excellence (NICE, UK) include ESWT as an option, although stating that current evidence on its efficacy is inconsistent [31]. However, these guidelines were produced

17 6 BioMed Research International in 2009, and much research has been performed into ESWT since then. The guidance also does not differentiate between focused and radial [31]. When looking specifically at reswt though, there is still some debate as to its efficacy. Whilst many studies have found reswt highly beneficial and conclude it to be a creditable treatment option [18, 32 34], others suggest no better results than the other established therapies [19, 35 37] or not different from placebo [38]. A recent systematic review and meta-analysis concluded that the efficacy of lowintensity ESWT is worthy of recognition [39]. Taking the evidence into account, ESWT is effective in short- and midterm follow-up in terms of pain and function, but its efficacy in the long term has to be established. Possible reasons for the conflicting findings may include the different protocols used. The protocol used in this study is as follows: a thorough patient examination including ultrasonography prior to treatment; a minimum of four to eight treatments spaced one week apart depending on patients response and the duration of the symptoms; a mean pressure of 1.7 bar, guided by the patient s pain; a mean frequency of 5 Hz; a mean total number of impulses of 2000; in our case only means and ranges are retrospectively examined. Therefore other studies which have variable numbers of treatment sessions, pressures, frequencies, and total impulses may have different outcomes to this study. Other studies have shown that multiple applications of ESWT produce better short- and long-term results than single session alone [40]. According to our protocol, the number of sessions prescribed has been shown to be enough to provoke a positive response, as seen in the results. Summarising the differing protocols with regard to the ESWT settings, there are no standardised recommendations on the treatment parameters [34] other than those published by the manufacturers of the devices, which can vary between devices. The Storz Medical Masterpuls reswt machine used in this study suggests the following for PF: 3 5 sessions, bar, impulses, and Hz frequency [41]. Variations of programmes, differentiating from device instructions, have been applied in similar cases as well [19, 32, 34, 42]. These variations in protocols could therefore account for the differences found, the opinions expressed in research studies suggesting that reswt was no better than physiotherapy [36, 37], opposite to those conveyed by others who found reswt to be a valuable treatment modality for PF [18, 32]. In 2007 a review [43] found ESWT as a whole to be a viable treatment option for chronic PF but also commented on the varying protocols used. It found that this is the fundamental flaw with regard to ESWT research, different protocols and conflicting evidence. The contradictory findings could be the result of these different protocols, due to the large number of variables, including the populations studied, the treatment parameters, and the various outcome measures [34]. What appears to have been concluded, however, is that there has to be a balance between pressure and time: the higher the pressure the less the sessions required, but the risk of damage increases, whilst the lower the pressure the more the sessions required to see any effects [44]. Therefore it can be said that there is a dose-related relationship [44]. Therefore in this study the pressure was kept low enough to prevent any damage but high enough to have positive results. In some cases if changes were not being observed, the pressure was increased with each session until they were seen. With regard to the 8% recurrence rate, this study found three key factors for recurrence: female sex, pretreatment pain duration, and the number of ESWT sessions received. With regard to the pretreatment pain duration, it is thought that recalcitrant PF could be caused by plantar fascia thickening and loss of normal tissue elasticity, that is, tissue degeneration over a period of time [45]. Therefore if a patient presents with advanced changes then they may be less receptive to conservative management. This could also explain the finding of increased recurrence with the number of sessions received (more advanced PF would require more sessions of ESWT). Corticosteroid injections are another treatment modality recommended for PF, but there are no studies directly comparing reswt and corticosteroid injections for the treatment of PF. Many compare injections with ESWT as a whole and have found injections more beneficial and more cost-effective [46, 47]. However, a Cochrane review concluded that whilst valuable in the short term, the effects of injection therapy are not maintained beyond six months [48]. In comparison, although expensive, some studies have concluded that ESWT has fewer complications and produces encouraging results both short- and long-term: for example, one study reported no complications and had positive short-term results (twothirds resuming full physical activity within two months) and long-term results (6% recurrence rate within 6 12 months) [23]. Therefore at this centre reswt is the treatment of choice. Limitations of the present study may be found in the fact that patients were not standardised in terms of age, sex, BMI, or occupation, which could lead to analysis exploring possible correlations or depopulation. Prior to commencing the study, a sample size calculation was not performed also bringing a limitation although anticipated by a post hoc power analysis of VAS scores t-tests repeated measurements. 5. Conclusion This study reports the recurrence rate, the mean VAS reductions, and success rates of the intervention, something not widely done in the literature. The protocol is tailored to the individual patient s needs and is hence much more flexible than other protocols used. By adapting the programme to the patient, it allows for better results as the treatment programme can progress at a rate suitable to the patient, due to the ability to allow for patient-guided feedback. Nonetheless, this study has shown encouraging results, and therefore this reswt protocol can be recommended for the treatment of PF. More research should be conducted with more flexible protocols such as this, in order to corroborate this study. They should also look at the implications of other variables such as gender and age, in order to assess whether programmes of reswt can be further tailored. Apparently,

18 BioMed Research International 7 meta-analysis techniques as well as the development of current good practice guidelines may assist in the fields of bringing together different outcome measures and reswt treatment protocols on PF. Disclosure The authors affirm that this paper is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained. Competing Interests Heinz Lohrer receives research support and is a paid speaker from Storz Medical. The other authors declare that there is no conflict of interests regarding the publication of this paper. Authors Contributions Nikos Malliaropoulos planned the study, performed the clinical work, and contributed to writing the paper. Georgina Crate performed the data collection, performed the literature review, and contributed to writing and editing the paper. Maria Meke performed the statistical analysis and contributed to writing and editing the paper. Vasileios Korakakis contributed to writing and editing the paper. Tanja Nauck contributed to writing the paper. Heinz Lohrer contributed to writing and editing the paper. Nat Padhiar contributed to writing the paper. Acknowledgments The authors are grateful to Storz Medical, Lohstampfestrasse 8, 8274 Tägerwilen, Switzerland, for funding the open access publication article processing charge. References [1] S. Cutts, N. Obi, C. Pasapula, and W. Chan, Plantar fasciitis, Annals of the Royal College of Surgeons of England, vol.94,no. 8, pp , [2] D. De Garceau, D. Dean, S. M. Requejo, and D. B. Thordarson, The association between diagnosis of plantar fasciitis and Windlass test results, Foot and Ankle International,vol.24, no. 3, pp , [3] A. M. A. Othman and E. M. Ragab, Endoscopic plantar fasciotomy versus extracorporeal shock wave therapy for treatment of chronic plantar fasciitis, Archives of Orthopaedic and Trauma Surgery,vol.130,no.11,pp ,2010. [4] J. Orchard, Plantar fasciitis, British Medical Journal, vol. 345, no. 7878, Article ID e6603, [5] A. A. Schepsis, R. E. Leach, and J. Gorzyca, Plantar fasciitis: etiology, treatment, surgical results, and review of the literature, Clinical Orthopaedics and Related Research,no.266,pp , [6] S. Mahmood, L. K. Huffman, and J. G. Harris, Limb-length discrepancy as a cause of plantar fasciitis, Journal of the American Podiatric Medical Association,vol.100,no.6,pp , [7] D. B. Irving, J. L. Cook, and H. B. Menz, Factors associated with chronic plantar heel pain: a systematic review, Journal of Science and Medicine in Sport,vol.9,no.1-2,pp.11 22,2006. [8] D. L. Riddle, M. Pulisic, P. Pidcoe, and R. E. Johnson, Risk factors for plantar fasciitis: a matched case-control study, The Journal of Bone & Joint Surgery American Volume,vol.85,no. 5, pp , [9] J. D. Rompe, C. Hopf, B. Nafe, and R. Bürger, Low-energy extracorporeal shock wave therapy for painful heel: a prospective controlled single-blind study, Archives of Orthopaedic and Trauma Surgery,vol.115,no.2,pp.75 79,1996. [10] D. S. Malay, M. M. Pressman, A. Assili et al., Extracorporeal shockwave therapy versus placebo for the treatment of chronic proximal plantar fasciitis: results of a randomized, placebo-controlled, double-blinded, multicenter intervention trial, Journal of Foot and Ankle Surgery,vol.45,no.4,pp , [11] P. F. Davis, E. Severud, and D. E. Baxter, Painful heel syndrome: results of nonoperative treatment, Foot & Ankle International, vol. 15, no. 10, pp , [12] L. H. Gill, Plantar Fasciitis: diagnosis and conservative management, Journal of the American Academy of Orthopaedic Surgeons,vol.5,no.2,pp ,1997. [13] J. L. Thomas, J. C. Christensen, S. R. Kravitz et al., The diagnosis and treatment of heel pain: a clinical practice guidelinerevision 2010, Journal of Foot and Ankle Surgery, vol. 49, no. 3, supplement, pp. S1 S19, [14] H. Al-Abbad and J. V. Simon, The effectiveness of extracorporeal shock wave therapy on chronic Achilles tendinopathy: a systematic review, Foot and Ankle International, vol. 34, no. 1, pp , [15] J. D. Rompe, A. Cacchio, J. P. Furia, and N. Maffulli, Lowenergy extracorporeal shock wave therapy as a treatment for medial tibial stress syndrome, American Journal of Sports Medicine,vol.38,no.1,pp ,2010. [16] V. Avancini-Dobrović, L. Frlan-Vrgoč, D. Stamenković, I. Pavlović, and T. S.-L. Vrbanić, Radial extracorporeal shock wave therapy in the treatment of shoulder calcific tendonitis, Collegium Antropologicum,vol.35,no.2,pp ,2011. [17] K.-V. Chang, S.-Y. Chen, W.-S. Chen, Y.-K. Tu, and K.-L. 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19 [Downloaded free from on Thursday, July 6, 2017, IP: ] Original Article Extracorporeal shock wave therapy of gastroc-soleus trigger points in patients with plantar fasciitis: A randomized, placebo-controlled trial Alireza Moghtaderi, Saeid Khosrawi, Farnaz Dehghan Department of Physical Medicine and Rehabilitation, Isfahan University of Medical Sciences, Isfahan, Iran Abstract Background: Plantar fasciitis is the most common cause of heel pain. Extracorporeal shock wave therapy (ESWT) is an alternative treatment for refractory cases of plantar fasciitis. Studies also demonstrated that ESWT may be an appropriate treatment for myofascial trigger points. This study was designed to evaluate its effectiveness by comparing the ESWT of Gastrocnemius/Soleus (gastroc-soleus) trigger points and heel region with the ESWT of the heel region alone. Materials and Methods: The study was carried out among 40 patients with a clinical diagnosis of plantar fasciitis, divided randomly to case (n = 20) and control (n = 20) groups. The case group received ESWT for the heel region and for the gastroc-soleus trigger points. The control group received ESWT just for the heel region. The protocol was the same in both groups and they were treated for three sessions every week. The pain score (100 mm visual analog score [VAS]) and the modified Roles and Maudsley score was evaluated before the first session and eight weeks after the last session. Results: Eight weeks after the last session, although the mean VAS had decreased significantly in both groups, this decrement was more significant in the case group. (P = 0.04). According to the modified Roles and Maudsley score, there was a significant improvement in both the case (P < 0.001) and control (P = 0.01) groups, eight weeks after treatment, but there were significantly better results in the case group. Conclusion: The combination of ESWT for both plantar fasciitis and gastroc-soleus trigger points in treating patients with plantar fasciitis is more effective than utilizing it solely for plantar fasciitis. Key Words: Extracorporeal shock wave therapy, plantar fasciitis, trigger points Address for correspondence: Dr. Saeid Khosrawi, Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Isfahan University of Medical Sciences, Sofeh St., Isfahan, Iran. khosrawi@med.mui.ac.ir Received: , Accepted: Access this article online Quick Response Code: Website: DOI: / INTRODUCTION Plantar fasciitis is the most common cause of inferior heel pain, and may account for up to 15% of all foot symptoms requiring professional care among adults. Plantar fasciitis affects women slightly more often than men. [1] The incidence peaks between the ages of 40 and 60 years. [2] Increased bodyweight and work on Copyright: 2013 Moghtaderi. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. How to cite this article: Moghtaderi A, Khosrawi S, Dehghan F. Extracorporeal shock wave therapy of gastroc-soleus trigger points in patients with plantar fasciitis: A randomized, placebo-controlled trial. Adv Biomed Res 2014;3:99. Advanced Biomedical Research

20 [Downloaded free from on Thursday, July 6, 2017, IP: ] Moghtaderi, et al.: ESWT of gastro-soleous trigger points in plantar fasciitis hard surfaces are the risk factors. [3-5] Reduced range of ankle dorsiflexion is associated with plantar fasciitis, [3] as are calf and hamstring tightness. [6] A great variety of therapies have been reported for the treatment of plantar fasciitis, including local steroid injections, platelet-rich plasma, intralesional botulinum toxin A (BTX-A), extracorporeal shock wave therapy, and a combination of all of these treatments with stretching exercises of the gastrocnemius and soleus muscles, or the plantar fascia. [7-14] Additionally, the effectiveness of trigger point needling in relieving plantar heel pain has been shown in some studies. [15-17] Some studies have also demonstrated that ESWT may be an appropriate treatment for myofascial trigger points. [18,19] As there is a lack of studies evaluating the effectiveness of ESWT of the gastroc-soleus trigger points in the treatment of plantar fasciitis, we designed this study to evaluate its effectiveness by comparing ESWT of the gastroc-soleus trigger points and heel region with the ESWT of the heel region alone. MATERIALS AND METHODS This study is a randomized, placebo-controlled trial, which was carried out from March 2012 to November 2012, among 40 patients, with a clinical diagnosis of plantar fasciitis, referred to the Outpatient Clinics of Kashani University Hospital, Isfahan, Iran [Figure 1]. The patients who met the following inclusion criteria were included into the study: (1) Patients who had heel pain felt it localized to the site of the insertion of the plantar fascia and intrinsic muscles on the medial calcaneal tuberosity on the anterior-medial aspect of the heel for at least six months. (2) Patients who had at least one gastroc-soleus trigger point concomitantly. (3) Patients who did not respond to conservative treatments for at least three months. (4) Patients who were between 20 and 60 years of age, and had signed the informed consent form. Exclusion criteria of the study were: (1) Dysfunction of the knee or ankle, local arthritis, generalized polyarthritis, rheumatoid arthritis, ankylosing spondylitis, and Reiter syndrome. (2) Neurologic abnormalities. (3) Bleeding tendency (hereditary or acquired). (4) Nerve entrapment syndromes such as the tarsal tunnel syndrome. (5) Previous operation on the heel. (6) Pregnancy. (7) Evidences of infection in the lower limbs. (8)Medical history of tumor. (9) Patients who had received local corticosteroid injection within 12 weeks. The patients were divided randomly into case (n = 20) and control (n = 20) groups. The case group received extracorporeal shock wave therapy (ESWT) (3000 shock waves/session of 0.2 mj/mm 2 ) for the heel region and (400 shock waves/session of 0.2 mj/mm 2 per each trigger point) for the gastroc-soleus trigger points. The control group received ESWT (3000 shock waves/ session of 0.2 mj/mm 2 ) for just the heel region. The Figure 1: CONSORT 2010 Flow Diagram of randomized clinical trial: number of participants screened, randomized, and retained and analyses 2 Advanced Biomedical Research 2014

21 [Downloaded free from on Thursday, July 6, 2017, IP: ] Moghtaderi, et al.: ESWT of gastro-soleous trigger points in plantar fasciitis protocol was the same in both groups and they were treated for three sessions every week. The Duolith SD1 shock wave machine was used and shock waves were applied to the site of maximum local tenderness. The pain score (100 mm visual analog score [VAS]) and the modified Roles and Maudsley score were evaluated before the first session and eight weeks after the last session. The modified Roles and Maudsley score was a patient-administered scoring system (see table A on bmj.com). [20] The article has been submitted and registered in www. clinicaltrial.gov as RCT number: NCT Statistical analysis Statistical analyses were performed using the statistical package for social sciences (SPSS) statistical package version 13.0 (SPSS Inc., Chicago, IL, USA). Independent sample t-test or Mann Whitney U-test, paired t-test or Repeated Measure ANOVA test, and the Chi Chi-square test were used to assess the differences between stages, as appropriate. A P-value less than 0.05 was considered significant. RESULTS Among 45 patients who had plantar fasciitis, five patients did not pass the screening protocol because they refused treatment (four patients), or were withdrawn because of violation of the selection criteria at entry (one patient). A total number of 40 patients were investigated after taking anamnesis and a thorough physical examination. In case group there were seven males (35%) and 13 females (65%) and the control group had six males (30%) and 14 females (70%). According to gender there was no significant difference between the two groups. The results showed that the mean VAS scores did not differ significantly before treatment between the case and control groups (P < 0.001). Eight weeks after the last session, the mean VAS was significantly lower in the case group (P < 0.05). Although the mean VAS had decreased significantly in both groups, this decrement was more significant in the case group. (P = 0.04) [Table 1]. According to the modified Roles and Maudsley score, there was no significant difference between the baseline scores of the two groups (P = 0.86). The results revealed that there was a significant improvement in both groups eight weeks after the last session, but the Wilcoxon test showed significantly better results in the case group [Table 2]. Power analysis demonstrated that a sample size of 20 plantar fasciitis groups would be necessary to show that ESWT for both the gastroc-soleous trigger points and the heel region was more accurate than ESWT for the heel region solely. (α = 0.05; β = 0.80). Here, the power of the test means the probabilityof rejecting the null hypothesis, given that the alternative hypothesis is true. The result is a decision regarding the sample size at a given α level (0.05) and statistical power (0.80). DISCUSSION As we have described, in recent years, several treatment options, including dry needling, injection of therapeutic medications (local anesthetics, steroids, botulinum toxin A), and ESWT have been studied for plantar fasciitis treatment. [7-17] The local steroid injection is an alternative treatment, which is commonly used for refractory plantar fasciitis. It has been shown that it may cause plantar fascia rupture, fat pad atrophy, lateral plantar nerve injury secondary to injection, and calcaneal osteomyelitis. [21,22] During the past decade, ESWT has been used increasingly worldwide, and based on some well-controlled trials, it has been recently approved by the food and drug administration (FDA) for treatment of plantar fasciitis in the United States of America. [23] It is a relatively safe procedure and can be considered before any surgical treatment. It may be preferable to try it before a local steroid injection. [24] Its proposed mechanism is cavitation of the deep tissue, which causes Table 1: Comparison of the visual analog scale scores before and after treatment within the case and control groups Time Case Mean+/-SD Control Mean+/-SD Before treatment 7+/ /-1.4 Eight weeks after treatment 3+/ /-1.1 P-value < SD: Standard deviation Table 2: Comparison of results of modified Roles and Maudsley score before and eight weeks after treatment in the case and control groups Score Time Group Case Control Excellent Baseline 1 1 Eight weeks after treatment 6 3 Good Baseline 4 5 Eight weeks after treatment 10 9 Acceptable Baseline 10 9 Eight weeks after treatment 2 5 Poor Baseline 5 5 Eight weeks after treatment 2 3 P value < Advanced Biomedical Research

22 [Downloaded free from on Thursday, July 6, 2017, IP: ] Moghtaderi, et al.: ESWT of gastro-soleous trigger points in plantar fasciitis micro rupture of capillaries, leakage of the chemical mediators, and promotion of neovascularization of the damaged tissue. [25] A study demonstrated that ESWT contributes to healing and pain reduction in plantar fasciitis, and ultrasound imaging is able to depict the morphological changes related to plantar fasciitis as a result of this therapy. [26] A quasi-experimental trial using 1% lidocaine injections for the myofascial trigger points, has found a reduction in pain, when combined with physical therapy. [19] Two trials have investigated the effectiveness of trigger point needling in relieving plantar heel pain. [15,16] Another study shows that trigger point dry needling by improving the severity of heel pain, can be used as a good alternative option before proceeding to more invasive therapies of plantar fasciitis, despite the insignificant effect on the range of motion of the ankle joint. [17] In this study we compared the effectiveness of ESWT for both the heel region and gastroc-soleus trigger points with ESWT just for the heel region. As the results showed, although both VAS and the modified Roles and Maudsley score had improved in both groups, the results were significantly better in the case group compared to the control group. This difference could be due to the fact that the myofascial trigger points of the calf muscles played an important role in pain perception and functional impairment of patients with plantar fasciitis. The improvement in both groups was consistent with the other studies that examined the effectiveness of ESWT in plantar fasciitis. Indeed, as we performed this study to evaluate the effectiveness of ESWT for gastroc-soleus trigger points in plantar fasciitis, we did not compare the different methods for applying that (e.g., radial vs. focus). Further studies are recommended to find out the mechanisms of action of ESWT on gastroc-soleus trigger points during the treatment of plantar fasciitis, along with comparing the different methods, to find the best method and dosage. On the basis of our findings, in summary, it can be stated that a combination of ESWT for both plantar fasciitis and gastroc-soleus trigger points in treating patients with plantar fasciitis is more effective than utilizing it solely for plantar fasciitis. REFERENCES 1. Riddle DL, Pulisic M, Sparrow K. Impact of demographic and impairment related variables on disability associated with plantar fasciitis. Foot Ankle Int 2004;25: Tu P, Bytomski JR. Diagnosis of heel pain. Am Fam Physician 2011;84: Irving DB, Cook JL, Menz HB. 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From the food and drug administration: Shock wave for heel pain. JAMA 2000;284: Hyer CF, VanCourt R, Block A. Evaluation of ultrasound-guided extracorporeal shock wave therapy in the treatment of chronic plantar fasciitis. J Foot Ankle Surg 2005;44: Tahririan MA, Motififard M, Tahmasebi MN, Siavashi B. Plantar fasciitis. J Res Med Sci 2012;17: Vahdatpour B, Sajadieh S, Bateni V, Karami M, Sajjadieh H. Extracorporeal shock wave therapy in patients with plantar fasciitis. A randomized, placebo-controlled trial with ultrasonographic and subjective outcome assessments. J Res Med Sci 2012;17: Source of Support: Nil, Conflict of Interest: None declared. 4 Advanced Biomedical Research 2014

23 This course was developed and edited from the open access article: Schmitz et al.: Treatment of chronic plantar fasciopathy with extracorporeal shock waves (review). Journal of Orthopaedic Surgery and Research :31. (doi: / x-8-31), used under the Creative Commons Attribution License. This course was developed and edited from the open access article: Success and Recurrence Rate after Radial Extracorporeal Shock Wave Therapy for Plantar Fasciopathy: A Retrospective Study - Hindawi Publishing Corporation, BioMed Research International: Volume 2016, Article ID , 8 pages. ( used under the Creative Commons Attribution License. This course was developed and edited from the open access article: Moghtaderi A, Khosrawi S, Dehghan F. Extracorporeal shock wave therapy of gastroc-soleus trigger points in patients with plantar fasciitis: A randomized, placebo-controlled trial. Adv Biomed Res 2014;3:99, used under the Creative Commons Attribution License.