Biofilm-associated infections in wounds or on implants are difficult to treat. Eradication of the bacteria is nearly always impossible, despite the use of specific antibiotics. The bactericidal effects of high-energy extracorporeal shock waves on Staphylococcus aureus have been reported, but the effect of low-energy shock waves on staphylococci and staphylococcal biofilms has not been investigated. In this study, biofilms grown on stainless steel washers were examined by electron microscopy. We tested ten experimental groups with Staph. aureus-coated washers and eight groups with Staph. epidermidis. The biofilm-cultured washers were exposed to low-energy shock waves at 0.16 mJ/mm. 2. for 500 impulses. The washers were then treated with cefuroxime, rifampicin and fosfomycin, both alone and in combination. All tests were carried out in triplicate. Viable cells were counted to determine the bactericidal effect. The control groups of Staph. aureus and Staph. epidermidis revealed a cell count of 6 × 10. 8. colony-forming units/ml. Complete eradication was achieved using the combination of antibiotic therapy (single antibiotic in Staph. aureus, a combination in Staph. epidermidis) and shock wave application (p < 0.01). We conclude that shock waves combined with antibiotics could be tested in an in vitro model of infection

Aims: A review of the existing literature is presented and compared with the results of a cohort study. These data are compared with the natural course of fracture healing. Methods: In a prospective cohort study 56 patients with nonunions and 14 patients with delayed unions after fracture or osteotomy were treated with shock wave therapy and followed for 2 years or to consolidation. These results and the previous data were assembled and were compared with the results of three studies on the natural course of fracture healing. Results: Consolidation was seen in 56% of patients with nonunions after a mean of 5.2 months, and in 93% of patients with delayed unions. The success rate of shock wave therapy was strongly associated with the time between primary diagnosis and shock wave therapy. Discussion: The success rate in the own cohort was quite similar to the results reported in the literature, after 3 months 52%, 41%, 19%, 40% or 25%, and 41%, 67%, 61% or 38% after 6 months respectively. At 12 months, healing occurred in up to 80%. The fractures were usually immobilised until union was assessed. It is not likely that a single intervention of shock wave therapy causes effects that last for several months. The results were compared with the natural course of fracture healing, also showing a time dependend healing rate. Conclusion: A considerable part of the effect of shock wave therapy may be attributed to the natural course of fracture healing, where healing is seen even after 6 or 12 months. Only a randomised study will be able to show whether shock wave therapy has any effect on fracture healing

The effects of extracorporeal shock waves (ESWT) on tendon healing were assessed by observing histological and biomechanical parameters in a rat model of injury to the tendo Achillis. The injury was created by inserting an 18-G needle through tendo Achillis in 48 adult Wistar albino rats. The animals were divided into three groups. The first group received radiation only after the operation. The second received no shock waves and the third had 500 15 KV shocks on the second post-operative day. All the rats were killed on the 21st day after surgery. Histopathological analysis showed an increase in the number of capillaries and less formation of adhesions in the study group compared with the control group (p = 0.03). A significantly greater force was required to rupture the tendon in the study group (p = 0.028). Our findings suggest a basis for clinical trials using ESWT

The aim of the study was to evaluate changes in clinical results after extracorporeal shock wave therapy (ESWT) on calcified lesions of the shoulder. 963 patients with calcifying tendinitis were treated with high energy shock waves. The mean energy flux density was 0. 28 mJ/mm2. To evaluate the effect we used the visual analogue scale (VAS) and the Roles-Maudsley-score to analyse the effect on activity of daily living, and pain perception. ESWT was indicated after non operative treatment failed. At 12 months after ESWT, 73. 6% of patients reported excellent and good results, 26% scored satisfactory and poor, using the Roles-Maudsley-Score. The positive effect of the ESWT on pain perception after 12 months was statistically significant (p< 0. 001). The difference between pain perception before and after ESWT persisted in the follow up interval. No decrease was shown after 2 years. In all cases no severe side effects were observed except small petechial haemorrhages. High energy shock wave therapy is indicated to treat calcifying tendinitis which is resistant to any other non-operative treatment. The decrease in pain perception persists over a period of more than two years. Absence of side effects and its effectiveness suggest that ESWT is indicated prior to surgical intervention

Aims. Proliferation, migration, and differentiation of anterior cruciate ligament (ACL) remnant and surrounding cells are fundamental processes for ACL reconstruction; however, the interaction between ACL remnant and surrounding cells is unclear. We hypothesized that ACL remnant cells preserve the capability to regulate the surrounding cells’ activity, collagen gene expression, and tenogenic differentiation. Moreover, extracorporeal shock wave (ESW) would not only promote activity of ACL remnant cells, but also enhance their paracrine regulation of surrounding cells. Methods. Cell viability, proliferation, migration, and expression levels of Collagen-I (COL-I) A1, transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF) were compared between ACL remnant cells untreated and treated with ESW (0.15 mJ/mm. 2. , 1,000 impulses, 4 Hz). To evaluate the subsequent effects on the surrounding cells, bone marrow stromal cells (BMSCs)’ viability, proliferation, migration, and levels of Type I Collagen, Type III Collagen, and tenogenic gene (Scx, TNC) expression were investigated using coculture system. Results. ESW-treated ACL remnant cells presented higher cell viability, proliferation, migration, and increased expression of COL-I A1, TGF-β, and VEGF. BMSC proliferation and migration rate significantly increased after coculture with ACL remnant cells with and without ESW stimulation compared to the BMSCs alone group. Furthermore, ESW significantly enhanced ACL remnant cells’ capability to upregulate the collagen gene expression and tenogenic differentiation of BMSCs, without affecting cell viability, TGF-β, and VEGF expression. Conclusion. ACL remnant cells modulated activity and differentiation of surrounding cells. The results indicated that ESW enhanced ACL remnant cells viability, proliferation, migration, and expression of collagen, TGF-β, VEGF, and paracrine regulation of BMSC proliferation, migration, collagen expression, and tenogenesis. Cite this article: Bone Joint Res 2020;9(8):457–467

The aim of this study is to explore the effect of extracorporeal shock wave therapy (ESWT) in patients with chronic planter faciitis. In this prospective study 70 heels in 62 patients with chronic planter faciitis in whom conventional conservative treatment consisting of nonsteroidal anti-inflammatory drugs, heel cup, orthoses and/or shoe modifications, local steroid injections have failed, were treated with low energy ESWT. Patients were reviewed at 6, 12 and 24 weeks post treatment. At follow-up there was significant decrease in pain on the visual analog scale (VAS) (p=0.27), with significant improvement in pain score (p=0.009) and in functional score (p< 0.001). The comfortable walking distance has increased significantly. There were no reported side effects. This study indicates that in patients with chronic plantar fasciitis, the ESWT provide a good pain relief and a satisfactory clinical outcome

Introduction. The pathophysiology of osteonecrosis of femoral head (ONFH) is uncertain for most cases with speculation of vascular impairment and changes in cell biology due to multi-factorial etiologies including corticosteroid, alcohol, smoking, trauma, radiation or caisson disease and genetic. Extracorporeal shockwave therapy (ESWT) began with an incidental observation of osteoblastic response pattern during animal studies in the mid-1980 that generated an interest in the application of ESWT to musculoskeletal disorders. The mechanism of shockwave therapy is not fully understood but several reports showed better clinical outcomes and promoted bone remodelling and regeneration effect of the femoral head after ESWT in ONFH. Therefore, we compared the clinical results of the use of extracorporeal shock wave therapy (ESWT) on the patients with ONFH in radiographic staging. Methods. We evaluated 24 patients with 32 hip joints diagnosed ONFH treated with ESWT from 1993 to 2012. Average follow-up period was 27 months, and patients were average 47.8 aged. Association Research Circulation Osseous (ARCO) staging system was used to grade radiographic stage before treatment. All the patients were divided to two groups; group 1 (ARCO stage I,II), group 2 (ARCO stage III). Comparative analysis was done between two groups with visual analogue scale (VAS) score and Harris hip score (HHS) at pre-treatment, 3, 6, 12 and 24 months after treatments. The failure was defined when radiographic stage was progressed or arthroplasty surgery was needed due to clinical exacerbation. Results. Two groups showed all clinical improvements with VAS scoring at final follow-up (group 1: mean 6.3 to 1.6, p < 0.001; group 2: mean 7.1 to 3.3, p < 0.001). With HHS, group 1 showed a significant improvement from 64.4 to 95.4 (p < 0.001), while no significance in group 2 (p = 0.280). At final-follow-up, 3 hips of group 1 and 1 hip of group 2 showed radiographic improvement, but 2 patients were performed total hip arthroplasty due to persistent pain and dysfunction. Discussion and Conclusion. ESWT could be considered as an alternative option before surgical treatment in patients not only with early stage of ONFH but also with mid stage

The aim of this study was to evaluate the analgesic effect of extracorporeal shock wave lithotripsy (ESWL) in patients with refractory tennis elbow, golfer’s elbow and plantar fasciitis. Patients with tennis elbow (34), golfer’s elbow (11) and plantar fasciitis lesions (14) who had not responded to a minimum of six months’ conservative treatment were included in this three-year study of ESWL. Patients who were pregnant or had neurological problems, coagulation disorder and tumour in the area of treatment were excluded. Patients received 2 000 shock waves of 0.04 to 0.12 mj/mnf three times at monthly intervals. Patients were followed up for a minimum of six months and maximum of 36 months. The effectiveness of ESWL was assessed in terms of improvement in duration and severity of pain, functional disability, complication of treatment and recurrence. Good or excellent results were achieved in 67.65% of patients with tennis elbow, 45.45% with golfer’s elbow and 71.42% with plantar fasciitis. ESWL seems a useful treatment option, as effective administered monthly as weekly. Its effectiveness in cases of golfer’s elbow in questionable

We report on our results of a pilot study in the use of extra-corporeal shock waves in the treatment of chronic calcific tendonitis of the shoulder. Twenty patients were randomised as part of a prospective controlled trial. 45% had subjective improvement with an increase of 11% in their constant score. This has statistical significance when compared with the control group. We found that ESWT is effective however patients found the treatment painful and we did not achieve the levels of success that had previously been reported in European studies

We aimed to determine whether extracorporeal shock waves of varying intensity would damage the intact tendo Achillis and paratenon in a rabbit model. We used 42 female New Zealand white rabbits randomly divided into four groups as follows: group a received 1000 shock-wave impulses of an energy flux density of 0.08 mJ/mm. 2. , group b 1000 impulses of 0.28 mJ/mm. 2. , group c 1000 impulses of 0.60 mJ/mm. 2. , and group d was a control group. Sonographic and histological evaluation showed no changes in group a, and transient swelling of the tendon with a minor inflammatory reaction in group b. Group c had formation of paratendinous fluid with a significant increase in the anteroposterior diameter of the tendon. In this group there were marked histological changes with increased eosin staining, fibrinoid necrosis, fibrosis in the paratenon and infiltration of inflammatory cells. We conclude that there are dose-dependent changes in the tendon and paratenon after extracorporeal shock-wave therapy and that energy flux densities of over 0.28 mJ/mm. 2. should not be used clinically in the treatment of tendon disorders

Purpose: To determine the effectiveness of rESWT for chronic plantar heel pain. Materials and methods: 70 patients were enrolled and randomly assigned to either active or placebo treatment. 2000 shock waves per session and 3 sessions were applied, interval of 2 weeks. The primary efficacy criteria were subjective outcome on Visual Analogue Scale (VAS) and Roles- and Maudsley-Score. The primary study endpoint was 12 weeks. Nonparametric procedures have been used for teststatistical analyses. In addition to P-values, results have been presented by means of Mann-Whitney estimators as nonparametric effect sizes and their one-sided 97.5% confidence intervals as required by the ICH E9 Guideline ( Exact Wilcoxon-Mann-Whitney test, ï ¡ = 0.025 one-sided). Results: 62 patients could be examined 12 weeks after rESWT. Drop out rate 12%. Significant decrease in pain sensation could be found in the active group (p< 0, 001). The VAS decreased from 7.1 (+/− 1,6) to 3.6 (+/− 2,3). Placebo group showed slight improvement from 6.7 (+/−1,8) to 5.9 (+/− 2,2). The effect size (Mann-Whitney) denotes a large superiority of the rESWT group (MW = 0.72). The lower bound of the asymptotic one-sided 97.5% confidence interval denotes superiority of the test group (LB-CI = 0.58). The results scored on Roles- and Maudsley-Score showed similar improvement. Only minor side effects as petechial bleeding and swelling were detected. Conclusion: The radial shock wave therapy is effective and save in treatment of chronic heel pain

During the last four years the author has used extracorporeal shock wave therapy (ESWT) to treat tendonoses, including 82 cases of tennis elbow, 108 cases of plantar fasciitis and 42 cases of related conditions. Treatment is administered in the consulting room without analgesia. This paper discusses the protocol used in selected cases. In 78% of cases, overall subjective and objective results were good to excellent, in 15% fair. In only 17% was the result poor, with no improvement. No cases of degeneration were encountered. There were few complications and these were minor. Because of the obvious clinical benefits in selected cases, this new modality of orthopaedic treatment is still being used daily after four years

Introduction: Although the application of low-energy Extracorporeal shock waves application (ESWA) to treat musculoskeletal disorders is controversial, there has been some limited, short-term evidence of its effectiveness for the treatment of chronic plantar fasciitis. Objective: The aim of this prospective study is to explore the effect of Extracorporal shock waves in patients with chronic planter faciitis. Methodology & results: In this prospective study 70 heels in 62 patients with chronic planter faciitis in whom conventional conservative treatment consisting of nonsteroidal anti-inßammatory drugs, heel cup, orthoses and/or shoe modiþcations, local steroid injections have failed, were treated with low energy ESWA. Standard radiographs of the affected heels were obtained before ESWA to document the existence of a calcaneal heel spur. Pre and post therapy subjective and objective scoring systems are being used to know the functional outcome (SF36 Health Survey score, Short Form McGill Pain Questionaire, American Orthopaedic foot and ankle society Hindfoot Scale, Visual analogue Pain score). Patients were reviewed at 6 and 12 weeks post treatment. At followup pain was decreased by 70% to 90% on the visual analog scale (VAS) and the comfortable walking time had increased signiþcantly. There were no reported side effects. Conclusion: This study indicates that in patients with chronic plantar fasciitis, the ESWA.provide a good pain relief and a satisfactory clinical outcome

Background: The aim of this study is to evaluate the efficacy of extracorpereal shock wave therapy (ESWT) in some of most frequent muscularskeletal pathologies. Material and methods: From July to October 2004 310 patients were treated with ESWT, suffering from the following pathologies: 96 symptomatic calcific tendonitis of the shoulder, 53 symptomatic sub-acromial impingement, 48 humeral epichondylitis, 52 plantar fasciitis, 24 pertrochanteric bursitis, 15 Achilleous tendinopathy and 22 patellar tendinopathy. Patients were evaluated clinically and instrumentally before the first application and at one and three months of follow-up. Three disability scales we utilized (NRS, Mcgill Pain Questionnaire e Chronic Pain Grade Questionnaire). Results: We observed a reduction of the pain and an increase of the articular functionality in 83% of calcific tendonitis of the shoulder, in 55% of sub-acromial impingement, in 76% of epichondylitis, in 74% of palantar fasciitis, in 90% of pertrochanteric bursitis, in 82% of Achilleous tendinopathy and in 86% of patellar tendinopaty. Discussion: The data confirm the therapy with ESWT is efficient in some of most frequent musculoskeletal pathologies, with variable outcome in the various pathologies under investigation

Context: Published data on extracorporeal shock wave therapy (ESWT) for chronic plantar fasciitis provide controversial evidence about the clinical relevance and effectiveness. Treatment parameters have significant influence on outcome and optimal treatment protocols have to be determined. Objective: To assess the effect size and safety of ESWT compared to placebo in the treatment of chronic painful heel syndrome with a new electromagnetic device and an optimized protocol. Design, Setting, and Participants: Prospective, double-blind, randomized, placebo-controlled trial conducted among 40 patients. Interventions: ESWT (0.25 mJ/mm. 2. ) or placebo without anesthesia. Both groups received 3 treatments of 2000 shock wave impulses, each session 1 week apart. Main Outcome Measures: The primary outcome was the percentage change of heel pain quantified by VAS composite score 12 weeks after the last intervention compared to baseline. Secondary endpoints were defined as changes of single VAS scores (morning pain, pain at daily activities and pain with force-meter application), success rates and changes in Roles and Maudsley score. Results: ESWT resulted in a 73.2% reduction of heel pain regarding the primary endpoint VAS composite score compared to baseline, being 32.7% superior to placebo. Effect size reached clinical relevance (Mann-Whitney effect size (MW) = 0.6737; 0.6400 being the benchmark for medium-sized, relevant superiority, p = 0.0302 single-sided). With regard to the percentage changes of the single VAS scores and the Roles and Maudsley score, the effect size denoted relevant superiority of the ESWT as well (all MWs ≥ 0.6400). No relevant adverse events occurred. Conclusion: The results of the present study advocate ESWT for refractory painful heel syndrome demonstrating clinically relevant effect sizes. Specific treatment protocols with proven effectiveness ought to be used in the clinical setting

Context: Published data on extracorporeal shock wave therapy (ESWT) for heel pain provide controversial evidence about the clinical effectiveness. In previous studies, three interventions of ESWT without local anaesthesia demonstrated excellent outcome. Objective: To give confirmatory proof of effectiveness and safety of focused ESWT administered without local anaesthesia in the treatment of chronic painful heel syndrome. Design and Participants: Prospective, double-blind, randomized, placebo-controlled multicenter FDA trial conducted among 250 patients. Interventions: ESWT (0.25 mJ/mm. 2. ) or placebo. Both groups received three interventions of 2000 shock wave impulses, each session 1 week apart. Main Outcome Measures: The primary outcome was the percentage change of heel pain quantified by VAS composite score, as well as the change of Roles and Maudsley score at 12 weeks after the last intervention compared to baseline. Secondary endpoints were defined as single success rates (more than 60% reduction of morning pain, pain at daily activities, and pain with force-meter), overall success rate, physician’s judgment of effectiveness; patient’s satisfaction with outcome, patient’s willingness to recommend treatment, and subject’s analgesic medication consumption. Results: Follow-up was excellent with 246 patients (98.4%) available for intention-to-treat analysis at 12-week follow-up. ESWT resulted in a 69.2% reduction of heel pain regarding the primary endpoint VAS composite score compared to baseline, compared to 34.5% for placebo (p=0.0027, one-sided). ESWT was also significantly superior to placebo for the Roles and Maudsley score (p=0.0006, one-sided). The combined overall result of the eight secondary criteria also showed statistical significance (P = 0.0015 one-sided, multivariate directional Wilcoxon-Mann-Whitney test). No clinically relevant device-related adverse events were recorded. Conclusion: The results of the present study provide confirmatory proof of effectiveness of ESWT without local anaesthesia in the treatment of refractory painful heel syndrome

Purpose of Study: Assessing short and long term eficacy of Extracorporal Shock Wave Therapy (ESWT) as a treatment for recalcitrant plantar fasciitis (PF). Methods: Prospective follow up of 63 heels among 50 patients with persistent PF patients, (mean age 57.2±10.5); symptoms’ duration 15.8±14.3 months, resistant to non-operative treatment modalities including steroid injections. All patients underwent thorough physical examination and AOFAS Hindfoot score was obtained before treatment and a follow-up examination one week and one year after applicaton of ESWT course. Pain was assessed by Visual Analog Scale (VAS) relating to six parameters: pain on first step in the morning, maximum pain intensity, pain during prolonged walking, standing, at the end of the day and night pain. ESWT was applied in five consecutive courses of 1500 impulses of 0.32mj/mm² once a week in a routine previously described manner. Results:. All the six VAS parameters decreased significantly post treatment. The Vas parameter of the first steps in the mornining was the most severe before 8.6±1.8 and after treatment 4.2±2.0 and 1.4±1.9 one year after tretment (p< 0.0001). Night pain was the less intenes before treatment 3.9±3.7 and was nearly eliminated to 0.9±1.6 and 0.2±0.8 after one week and a one year post treatment (p< 0.0001). AOFAS hind-foot Score increased from 49.7±15.8 before ESWT to 87.7±10.9 and 86.3±10.7 one week and year after the courses (p< 0.0001). Three patients couldn’t complete the ESWT course one, one of them with bilateral PF. From those patients two had tarsal tunnel syndrome and one with the tibial nerve first branch which was fassing through the plantar fascia. There were no side effects other than minimal local discomfort during the session time. Conclusion: ESWT is a safe, efficient treatment modality for resistant PF

Introduction: The extracorporeal shock wave therapy (ESWT) has a wide spectrum of indication in orthopaedics. However, infection in the application area is regarded as a contraindication. Therefore, in this study, the effect of of ESW on bacteria and their interaction with antibiotics is tested. Methods: Standardized suspensions of S. aureus (ATCC25923) were exposed to different energy flux densities (EFD 0,38–0,96 mJ/mm. 2. ) and different impulse quantities (1000–12000 impulses) of a focussed ESWT. The surviving bacteria were quantified and compared to an untreated control group. The permeability of the cell wall of treated bacteria was analysed with a fluorescence assay and the DNA examined qualitatively for defects. The influence of ESW on the effectiveness of antibiotics was examined using Gentamicin whose stability under influence of ESW was proven infrared-spectrometrically earlier. S. aureus in specific broth (CAMHB) was treated with 4000 impulses at 0.59 mJ/mm. 2. Then the MIC against Gentamicin was compared with the MIC of an untreated control group. For the examination of synergistic effects between antibiotics and ESW, bacteria were treated with ESW (4000 impulses, 0.59 mJ/mm. 2. ) in a solution of CAMHB and varying Gentamicin concentrations (0.25 – 4 μ g/ml). The vital bacteria were quantified and compared to the control group which was exposed to either ESW or Gentamicin. Bacterium colonies were quantified according to the guidelines of the NCCLS, the statistical evaluation was done with the Man-Whitney-U- test. Results: The ESW showed a significant germicidal effect (P < 0.01) after application of either a high EFD (> 0.60 mJ/mm. 2. , 4000 impulses) or a high impulse quantitiy at low EFD (up to 12,000 impulses, < 0.60 mJ/mm. 2. ). The amount of CFU could be reduced by up to 99.9%. Despite the germicidal effect of the ESWT neither a change of the bacterium cell permeability nor a damage to the DNA could be proved. Synergistic effects between Gentamicin and ESW were not found. No loss of effectivity of the Gentamicins at a simultaneous application of the ESW (P > 0.05) could be seen either. Conclusion: The ESWT has a significant germicidal effect on bacteria after exceeding a certain threshold energy. It could be shown that the applied total energy is responsible for the germicidal effect rather than single paramters as EFD and impulse quantity. A synergistic effect of antibiotics applied in addition to the ESW could not be proved. When ESW was carried out in presence of Gentamicin, the antibacterial effect of Gentamicin was influenced neither positively nore negatively. The simultaneous application of ESW and systemically or locally applied antibiotics could represent a new therapy approach against tissue and bone infections. To prove this, further in-vivo studies are needed

Extracorporal shock wave therapy (ESWT) seems to be a promising new tool for the treatment of chronic pain due to tendinopathies such as tennis elbow or a painful heel. Mechanisms of ESWT-induced analgesia are still unknown. One major system for controlling pain is the endogenous opioid system that could be the biochemical basis of the ESWT-effects. The aim of the study was to investigate the possible influence of low energy ESWT on the endogenous opioid-system in the lumbar spinal cord of the rat. Immunohistochemical analysis of the expression of opioids Met-Enkephalin (MRGL), and dynorphin (Dyn) were performed in rats treated either once with 1000 impulses or three times with 1000 impulses with two different energy flux densities each (0.04 and 0.11 mJ/mm. 2. ) at 4 or 72 h after ESWT. No different immunoreactivity of MRGL and Dyn was seen after single ESWT treatment in comparison with the sham group. This result was not influenced by different energy flux doses or repetitive ESWT treatment. Met-Enk and Dyn expression was similar on ipsi- and contralateral side and was unchanged at later time points after ESWT treatment. Low energy ESWT had no influence on the opioid-systems and therefore does not trigger this endogenous anti-nociceptive system under basal conditions. Furthermore these results show that low energy ESWT had no side effects on rat spinal cord (e.g. neuronal destruction or enhanced permeability of the blood brain barrier for leukocytes) even after the application of 3 x 1000 impulses with the energy flux density as high as 0.11 mJ/mm. 2. Although applications in orthopaedics have outnumbered those in urology, there is no firm evidence of efficacy of ESWT in orthopaedics from well-designed randomised clinical trials and the molecular mechanisms of the of the anti-nociceptive effect of ESWT are still unknown

Aims: Primary aim of this study was to evaluate the inßuence of simultaneous local anesthesia on the clinical outcome after repetitive low-energy extracorpreal shock wave therapy (ESWT) for chronic tennis elbow. Methods: 51 patients were treated in a randomized single-blind international multicenter trial with a parallel-group design and blinded independent observer to evaluate low-energy ESWT with local anesthesia versus placebo ESWT with local anesthesia for patients with a chronic tennis elbow at three-month follow-up. 85% of patients of the verum group did not achieve good/ excellent results in the Roles & Maudsley score, they were offered once again application of the identical active treatment concept, this time without local anesthesia. 80% of the patients of the placebo group did not achieve good/excellent results, they were offered crossover therapy, i.e. identical active treatment with local anesthesia. Results: Reception of active therapy without local anesthesia resulted in excellent or good outcomes in 80% of patients of the original verum group at three-month follow-up, while application of active therapy with local anesthesia lead to good outcomes in 27% of the original placebo group (p= 0.0092, power= 0.8). Conclusions: Local anesthesia has a negative inßuence on the clinical outcome after repetitive low-energy ESWT for chronic tennis elbow