Unfocused extracorporeal shock wave therapy as potential treatment for osteoporosis

Shockwave Therapy in Veterinary Rehabilitation

Extracorporeal shockwave therapy (ESWT) is a noninvasive treatment that involves the transcutaneous delivery of high-energy sound waves into tissue creating therapeutic effects. Shockwaves are nonlinear, high-pressure, high-velocity acoustic waves characterized by low tensile amplitude, short rise time to peak pressure, and a short duration (less than 10 milliseconds). ESWT has been shown to increase the expression of cytokines and growth factors leading to decreased inflammation, neovascularization, and cellular proliferation; activation of osteogenesis by osteoblast differentiation and then by increased proliferation; inhibition of cartilage degeneration and rebuilding of subchondral bone; and increased serotonin in the dorsal horn and descending inhibition of pain signals. Musculoskeletal conditions that can benefit from ESWT include osteoarthritis, tendinopathies, fracture/bone healing, and wound healing.

A microexplosive shockwave-based drug delivery microsystem for treating hard-to-reach areas in the human body

Implantable drug-delivery microsystems have the capacity to locally meet therapeutic requirements by maximizing local drug efficacy and minimizing potential side effects. The internal organs of the human body including the esophagus, gastrointestinal tract, and respiratory tract, with anfractuos contours, all manifest with endoluminal lesions often located in a curved or zigzag area. The ability of localized drug delivery for these organs using existing therapeutic modalities is limited. Spraying a drug onto these areas and using the adhesion and water absorption properties of the drug powder to attach to lesion areas can provide effective treatment. This study aimed to report the development and application of microsystems based on microshockwave delivery of drugs. The devices comprised a warhead-like shell with a powder placed at the head of the device and a flexible rod that could be inserted at the tail. These devices had the capacity to deposit drugs on mucous membranes in curved or zigzag areas of organs in the body. The explosive impact characteristics of the device during drug delivery were analyzed by numerical simulation. In the experiment of drug delivery in pig intestines, we described the biosafety and drug delivery capacity of the system. We anticipate that such microsystems could be applied to a range of endoluminal diseases in curved or zigzag regions of the human body while maximizing the on-target effects of drugs.

The Effects of the Exposure of Musculoskeletal Tissue to Extracorporeal Shock Waves

Extracorporeal shock wave therapy (ESWT) is a safe and effective treatment option for various pathologies of the musculoskeletal system. Many studies address the molecular and cellular mechanisms of action of ESWT. However, to date, no uniform concept could be established on this matter. In the present study, we perform a systematic review of the effects of exposure of musculoskeletal tissue to extracorporeal shock waves (ESWs) reported in the literature. The key results are as follows: (i) compared to the effects of many other forms of therapy, the clinical benefit of ESWT does not appear to be based on a single mechanism; (ii) different tissues respond to the same mechanical stimulus in different ways; (iii) just because a mechanism of action of ESWT is described in a study does not automatically mean that this mechanism is relevant to the observed clinical effect; (iv) focused ESWs and radial ESWs seem to act in a similar way; and (v) even the most sophisticated research into the effects of exposure of musculoskeletal tissue to ESWs cannot substitute clinical research in order to determine the optimum intensity, treatment frequency and localization of ESWT.

Ovariectomized Rat Model and Shape Variation in the Bony Labyrinth

Postmenopausal osteoporosis is a serious concern in aging individuals, but has not been explored for its potential to alter the shape of the inner ear by way of increased remodelling in the otic capsule. The otic capsule, or bony labyrinth, is thought to experience uniquely limited remodelling after development due to high levels of osteoprotegerin. On this basis, despite the widespread remodelling that accompanies osteoporosis, we hypothesize that both the shape and volume of the semicircular canals will resist such changes. To test this hypothesis, we conducted three-dimensional geometric morphometric shape analysis on microcomputed tomographic data collected on the semicircular canals of an ovariectomized (OVX) rat model. A Procrustes ANOVA found no statistically significant differences in shape between surgery and sham groups, and morphological disparity testing likewise found no differences in shape variation. Univariate testing found no differences in semicircular volume between OVX and control groups. The range of variation in the OVX group, however, is greater than in the sham group but this difference does not reach statistical significance, perhaps because of a combination of small effect size and low sample size. This finding suggests that labyrinthine shape remains a tool for assessing phylogeny and function in the fossil record, but that it is possible that osteoporosis may be contributing to intraspecific shape variation in the bony labyrinth. This effect warrants further exploration at a microstructural level with continued focus on variables related to remodelling. This article is protected by copyright. All rights reserved.

Improved biomechanics in experimental chronic rotator cuff repair after shockwaves is not reflected by bone microarchitecture

Purpose

The aim of this study was to investigate the effect of extracorporeal shockwave therapy (ESWT) on bone microstructure as well as the bone-tendon-interface and the musculo-tendinous transition zone to explain the previously shown improved biomechanics in a degenerative rotator cuff tear animal model. This study hypothesized that biomechanical improvements related to ESWT are a result of improved bone microstructure and muscle tendon properties.

Methods

In this controlled laboratory study unilateral supraspinatus (SSP) tendon detachment was performed in 48 male Sprague-Dawley rats. After a degeneration period of three weeks, SSP tendon was reconstructed transosseously. Rats were randomly assigned into three groups (n = 16 per group): control (noSW); intraoperative shockwave treatment (IntraSW); intra- and postoperative shockwave treatment (IntraPostSW). Eight weeks after SSP repair, all rats were sacrificed and underwent bone microstructure analysis as well as histological and immunohistochemical analyses.

Results

With exception of cortical porosity at the tendon area, bone microstructure analyses revealed no significant differences between the three study groups regarding cortical and trabecular bone parameters. Cortical Porosity at the Tendon Area was lowest in the IntraPostSW (p≤0.05) group. Histological analyses showed well-regenerated muscle and tendon structures in all groups. Immunohistochemistry detected augmented angiogenesis at the musculo-tendinous transition zone in both shockwave groups indicated by CD31 positive stained blood vessels.

Conclusion

In conclusion, bone microarchitecture changes are not responsible for previously described improved biomechanical results after shockwave treatment in rotator cuff repair in rodents. Immunohistochemical analysis showed neovascularization at the musculo-tendinous transition zone within ESWT-treated animals. Further studies focusing on neovascularization at the musculo-tendinous transition zone are necessary to explain the enhanced biomechanical and functional properties observed previously.

Clinical relevance

In patients treated with a double-row SSP tendon repair, an improvement in healing through ESWT, especially in this area, could prevent a failure of the medial row, which is considered a constantly observed tear pattern.

The effect of magnetic therapy and moderate aerobic exercise on osteoporotic patients: A randomized clinical study

BACKGROUND

Osteoporosis is a frequent musculoskeletal condition with significant complications that would be a global health problem and one of the major causes of mortality and morbidity.

OBJECTIVES

The current study aimed to ascertain the impact of pulsed magnetic therapy, aerobic exercise, and a combination of both modalities on osteoporotic female patients postthyroidectomy.

METHODS

Between May 2018 and September 2019, 45 female patients with osteoporosis were included in the randomized clinical study, their age ranged from 40 to 50 years, had thyroidectomy for at least 6 months ago, and had an inactive lifestyle for at least the previous 6 months. Patients were assigned randomly into 3 equal groups. Group A (magnetic therapy group): received routine medical treatment (bisphosphonates, calcium, and vitamin D) in addition to pulsed magnetic therapy on the hip region for 12 weeks (3 sessions/week). Group B (exercise group): received routine medical treatment plus moderate-intensity aerobic exercise for 12 weeks (3 sessions/week). Group C (combined magnetic therapy and exercise therapy group): received routine medical treatment plus pulsed magnetic therapy and moderate-intensity aerobic exercise for 12 weeks (3 sessions/week). The 3 groups were assessed for bone mineral density (BMD) at baseline by dual-energy x-ray absorptiometry and after 12 weeks of treatment.

RESULTS

The results showed that within-group analysis a statistically significant increase was reveled (P < .05) for BMD in the 3 studied groups. Comparing the results among the 3 tested groups revealed a significant increase (P < .05) in posttesting mean values of BMD in group (C) compared to group (A) and group (B). No significant statistical difference in BMD means values between the 2 groups (A) and (B) after testing was detected.

CONCLUSION

Combination of both pulsed magnetic therapy and moderate-intensity aerobic exercise showed significant improvement in BMD at the hip region than using any of the 2 modalities alone.

Utilization of Mechanical Stress to Treat Osteoporosis: The Effects of Electrical Stimulation, Radial Extracorporeal Shock Wave, and Ultrasound on Experimental Osteoporosis in Ovariectomized Rats

Current treatment options for osteoporosis primarily involve pharmacotherapies, but they are often accompanied by undesirable side effects. Utilization of mechanical stress which can noninvasively induce bone formation has been suggested as an alternative to conventional treatments. Here, we examined the efficacy of mechanical stress induced by electrical stimulation, radial extracorporeal shock waves, and ultrasound for estrogen-deficient osteoporosis. Female Wistar rats were divided into following five groups: sham-operated group, untreated after ovariectomy, and treated with electrical stimulation, radial extracorporeal shock wave, or ultrasound starting at 8 weeks after ovariectomy for 4 weeks. Trabecular bone architecture of the femur was assessed by micro-CT and its biomechanical properties were obtained by mechanical testing. The femurs were further evaluated by histochemical, immunohistochemical, and real-time PCR analyses. Radial extracorporeal shock wave and ultrasound treatment improved trabecular bone microarchitecture and bone strength in osteoporotic rats, but not electrical stimulation. The shock wave decreased osteoclast activity and RANKL expression. The exposure of ultrasound increased osteoblast activity and β-catenin-positive cells, and they decreased sclerostin-positive osteocytes. These findings suggest that mechanical stress induced by radial extracorporeal shock wave and ultrasound can improve estrogen-deficient bone loss and bone fragility through promoted bone formation or attenuated bone resorption.

Efficacy of Unfocused Medium-Intensity Extracorporeal Shock Wave Therapy (MI-ESWT) for Plantar Fasciitis

Extracorporeal shock wave therapy (ESWT) is a promising treatment for plantar fasciitis (PF), however, treatment results have varied due to inconsistencies among types of shock wave treatment and devices used. This retrospective chart review includes patients who underwent ESWT using the OrthoGold 100™ shock wave device (MTS, Konstanz, Germany) for PF between January, 2013 and September, 2018. There were 108 patients (119 heels) identified, with a mean age of 51.7 ± 16.5 (Range 21-83) years. Patients were treated weekly for 3 weeks, with 2000 impulses per session at an energy flux density between 0.10 and 0.17 mJ/mm². Mean follow-up duration was 11.5 ± 9.7 (Range 3-51) months. Mean pre-ESWT pain visual assessment scale improved from 6.7 ± 1.7 to 2.6 ± 2.7 (p < .001). The Foot and Ankle Outcome Score subscales: pain, function of daily living, function of sports and recreational activities and quality of life domains improved from 53.7 ± 14.9 to 75.7 ± 16.7 (p < .001), from 38 ± 15.2 to 71.8 ± 23 (p < .001), from 55.8 ± 16.4 to 71.4 ± 18 (p < .001), from 42.4 ± 21.5 to 59.4 ± 20.3 (p < .001) and from 44.9 ± 16.4 to 69 ± 23.9 (p < .001), respectively. Eighty-eight (81.5%) patients were satisfied with the procedure at final follow-up. Treatment of PF with unfocused shock waves was well tolerated and led to significant pain reduction, functional improvement, and patient satisfaction.

The role of shockwaves in the enhancement of bone repair - from basic principles to clinical application

Extracorporeal shockwave therapy is a treatment modality, originally introduced into the clinic as lithotripsie, which has also been successfully used in the last two decades in the non-invasive treatment of delayed or non-healing fractures. Initially, the mechanism of action was attributed to microfracture-induced repair, but intensive basic research has now shown that the shockwave generates its effect in tissue via mechanotransduction. Numerous signal transduction pathways have already been demonstrated, which in their entirety trigger an endogenous regeneration process via cell proliferation, migration and differentiation. Clinically, these shockwave-conveyed biological signals support healing of acute, delayed and non-union fractures. The attainable outcome is comparable to surgery but avoiding an open approach with associated potential complications. These advantageous properties with a clearly positive cost-benefit ratio make shockwave therapy a first line treatment in delayed and non-union fractures.

Effects of ultrasound, radial extracorporeal shock waves, and electrical stimulation on rat bone defect healing

Fractures associated with osteoporosis are a major public health concern. Current treatments for fractures are limited to surgery or fixation, leading to long-term bedrest, which is linked to increased mortality. Alternatively, utilization of physical agents has been suggested as a promising therapeutic approach for fractures. Here, we examined the effects of ultrasound, radial extracorporeal shock waves, and electrical stimulation on normal or osteoporotic fracture healing. Femoral bone defects were created in normal or ovariectomized rats. Rats were divided into four groups: untreated, and treated with ultrasound, shock waves, or electrical stimulation after surgery. Samples were collected at 2 or 4 weeks after surgery, and the healing process was evaluated with micro-CT, histological, and immunohistochemical analyses. Ultrasound at intensities of 0.5 and 1.0 W/cm² , but not 0.05 W/cm² , accelerated new bone formation. Shock wave exposure also increased newly formed bone, but formed abnormal periosteal callus around the defect site. Conversely, electrical stimulation did not affect the healing process. Ultrasound exposure increased osteoblast activity and cell proliferation and decreased sclerostin-positive osteocytes. We demonstrated that higher-intensity ultrasound and radial extracorporeal shock waves accelerate fracture healing, but shock wave treatment may increase the risk of periosteal callus formation.

Shockwave Therapy Modulates the Expression of BMP2 for Prevention of Bone and Cartilage Loss in the Lower Limbs of Postmenopausal Osteoporosis Rat Model

Osteoporosis (OP) causes bone loss and weakness, increasing the risk of bone fracture. In this study, rats were divided into Sham, OP, SW(F) (0.25 mJ/mm² with 1600 impulses to the left medial femur), and SW(T) (0.25 mJ/mm² with 1600 impulses to the left medial tibia). The bone strength results following SW(T) were better than SW(F) in the modulus, extension at peak load, handleability, and strain at break. SW(T) had the best prevention for bone loss in both lower limbs of ovariectomized (OVX) rats. The cartilage cellular matrixes of both knees were improved in SW(T) and SW(F) compared to that of OP. Serum bone morphogenetic protein 2 (BMP2) in rats undergoing SW(T) or SW(F) was significantly improved compared to that in Sham and OP. The expressions of BMP2, BMP4, and SMAD family member 4 (Smad4) in addition to the Wnt family member 3A (Wnt3a) and Cyclin D1 signaling key factors were significantly induced in the cartilage of both knees by shockwave (SW). SW(T) presented the best efficacy to induce serum BMP2 to prevent bone loss from both lower limbs. Here, we display the protective effects of SW therapy to induce BMP2, BMP4, Smad4, Wnt3a, and Cyclin D1 signaling factors for cartilage loss in both knees of OVX rats.

Extracorporeal shock wave therapy: an update

Extracorporeal shock wave therapy (ESWT) is a safe therapy and there are only a few side effects known (such as pain during ESWT and minor haematomata), but no severe complications are to be expected if it is performed as recommended.

Contraindications are severe coagulopathy for high-energy ESWT, and ESWT with focus on the foetus or embryo and focus on severe infection.

The effect mechanism of ESWT is still a component of diverse studies, but as far as we can summarize today, it is a similar process to a cascade triggered by mechano-transduction: mechanical energy causes changes in the cellular skeleton, which provokes a reaction of the cell core (for example release of mRNA) to influence diverse cell structures such as mitochondria, endoplasmic reticulum, intracellular vesicles, etc., so the enzymatic response leads to the improvement of the healing process.

The usage of ESWT should be taught, to improve the outcome. Courses should be organized by national societies, since the legal framework conditions are different from one country to another.

In this update the musculoskeletal indications are addressed (mainly bone and tendons): pseudoarthrosis, delayed fracture healing, bone marrow oedema and osteonecrosis in its early stages, insertional tendinopathies such as plantar fasciitis and Achilles tendon fasciitis, calcifying tendonitis of the rotator cuff, tennis elbow, and wound healing problems.

Cite this article: EFORT Open Rev 2020;5:584-592. DOI: 10.1302/2058-5241.5.190067

Ingestion of gastrolith mineralized matrix increases bone volume and tissue volume in mouse long bone fracture model

Purpose

Fracture healing often requires extended convalescence as the bony fragments consolidate into restored viable tissue for load-bearing. Development of interventions to improve healing remains a priority for orthopaedic research. The goal of this study was to evaluate the ability of a naturally occurring matrix of amorphous calcium carbonate to affect fracture healing in an uninstrumented long bone model.

Methods

Complete transverse fracture was induced in the fibula of mature mice, followed by daily gavage of crushed gastrolith from crayfish at doses of 0 (control), 1 (1 MG), and 5 (5 MG) mg/kg. At Day 17, bones and sera were harvested.

Results

Morphologically, the 1 MG treated group had greater bone volume (BV), and both 1 MG and 5 MG had greater tissue volume (TV) than control (p < 0.05), as determined by μCT; BV/TV and mineral density did not yield a statistical difference. Histologically, regional variations in mineralized matrix were evident in all specimens, indicating a broad continuum of healing within the callus. Among serum proteins, bone-specific alkaline phosphatase, indicative of active mineralization, was greater in 5 MG than control (p < 0.05). Sclerostin, an inhibitor of osteogenesis, was lower in 5 MG than control (p < 0.05), also suggestive of enhanced healing.

Conclusions

An increase in bone volume, tissue volume and cellular signaling for osteogenesis at 17 days following fibula fracture in this mouse model suggests that gastrolith treatment holds potential for improving fracture healing. Further study at subsequent time points is warranted to determine the extent to which the increase in callus size with gastrolith treatment may accelerate restoration of tissue integrity.

The assessment of new bone formation induced by unfocused extracorporeal shock wave therapy applied on pre-surgical phase of distraction osteogenesis

Purpose:

This study aims to evaluate the effects of extracorporeal shock wave therapy applied before and/or immediately after the osteotomy on the maturation during the consolidation phase.

Materials and methods:

21 female New Zealand rabbits were used in the study. Subjects were divided randomly into three groups: Control (Distraction without ESWT), A (Distraction +ESWT After Osteotomy), AB (Distraction+ESWT After and Before Osteotomy). ESWT (500 pulses, 5 Hz, 0.19 mJ/mm2 energy flux density) was applied to group A and group AB after 5, 12 and 19 days after osteotomy and group AB only on days 7,14 and 21 before osteotomy. On the 28th day of the consolidation period, all subjects were sacrificed. Dual-energy x-ray absorptiometry (DEXA) was used to determine bone mineral density (BMD) and bone mineral content (BMC), and stereological methods were used to determine the new bone, connective tissue and neovascularization volumes.

Results:

As a result of DEXA examinations made on the 1st and 4th week of consolidation, there was no significant difference between groups regarding BMD and BMC values. According to the results of stereological examination, when the connective tissue and new bone tissue were evaluated, higher values were observed in AB when compared to A, and in AB and A compared to the control group, but the differences are not statistically significant. There was no difference between the groups in terms of neovascularization.

Conclusion:

ESWT in these parameters was not positively effective in bone maturation during consolidation when applied before osteotomy or both before and after osteotomy.

Effect of unfocused extracorporeal shockwave therapy on bone mineral content of twelve distal forearms of postmenopausal women: a clinical pilot study

Extracorporeal shockwave therapy showed a pronounced effect on bone mass in previous animal studies. We showed in this pilot study that a single treatment with unfocused shockwave therapy in unselected patients does not show side effects. Although our study did not show any effect of shockwave on BMD, the limited sample size does not definitively exclude this and a study with 174 subjects per group would be needed to show an effect size of 0.3 with a power of 80%.

PURPOSE

Unfocused extracorporeal shockwave therapy might stimulate bone formation to reduce the fracture risk. In this study, we assessed the safety of unfocused extracorporeal shockwave therapy and its effects on bone mass.

METHODS

A clinical pilot study with twelve female patients free of bone disease undergoing elective surgery of the lower extremity or elective spinal surgery under general anesthesia received 3.000 electrohydraulic-generated unfocused extracorporeal shockwaves (energy flux density 0.3 mJ/mm²) to one distal forearm. The contralateral forearm served as a control. We examined the effect on bone mass with the use of repeated dual energy X-ray absorptiometry measurements and we measured patient discomfort around the therapy.

RESULTS

No difference in bone mineral content and density was measured 6 and 12 weeks after therapy. shockwave therapy occasionally caused transient erythema or mild hematoma, but no discomfort in daily life or (late) adverse events.

CONCLUSIONS

Unfocused extracorporeal shockwave therapy is a safe treatment, but no increase in bone mass on the forearm was found at 0.3 mJ/mm² energy flux density. In this study, we were not able to demonstrate that a single treatment with unfocused shockwave therapy in unselected patients had any effect in terms of bone mineral density (BMD) or bone mineral content (BMC). A power analysis indicated that 174 patients per group are required to show an effect size of 0.3 with a power of 80%.

Unfocused shockwaves for osteoinduction in bone substitutes in rat cortical bone defects

Bone substitutes are frequently used in clinical practice but often exhibit limited osteoinductivity. We hypothesized that unfocused shockwaves enhance the osteoinductivity of bone substitutes and improve osteointegration and angiogenesis. Three different bone substitutes, namely porous tricalcium phosphate, porous hydroxyapatite and porous titanium alloy, were implanted in a critical size (i.e. 6-mm) femoral defect in rats. The femora were treated twice with 1500 shockwaves at 2 and 4 weeks after surgery and compared with non-treated controls. The net volume of de novo bone in the defect was measured by microCT-scanning during 11-weeks follow-up. Bone ingrowth and angiogenesis in the bone substitutes was examined at 5 and 11 weeks using histology. It was shown that hydroxyapatite and titanium both had an increase of bone ingrowth with more bone in the shockwave group compared to the control group, whereas resorption was seen in tricalcium phosphate bone substitutes over time and this was insensitive to shockwave treatment. In conclusion, hydroxyapatite and titanium bone substitutes favour from shockwave treatment, whereas tricalcium phosphate does not. This study shows that osteoinduction and osteointegration of bone substitutes can be influenced with unfocused shockwave therapy, but among other factors depend on the type of bone substitute, likely reflecting its mechanical and biological properties.

The Effect of Different Doses of Extracorporeal Shock Waves on Experimental Model Mandibular Distraction

OBJECTIVE

Distraction osteogenesis (DO) is widely used treatment for the bone deformities. In addition extracorporeal shock wave therapy (ESWT) is a new perspective on noninvasive modalities of management of the bone regeneration. We examined the effects of 2 different single doses of ESWT on the consolidation period of DO of the rabbit mandible using stereological, radiological and immunohistochemical methods in the present study.

METHODS

DO was performed unilaterally in the mandible of 18 New Zealand rabbits (6 months' old, weighing between 2.5 and 3 kg). The distraction zone of the mandible has received no treatment as controls. Group 2 (ESWT 500) received ESWT (single dose of 500 impulses 0.19 mJ/mm energy flux intensity and 2155 mJ totally) were applied on the first day of the consolidation. Group 3 (ESWT 1000) treated with ESWT (single dose of 1000 impulses0.19 mJ/mm energy flux intensity and 4310 mJ totally) were applied on the first day of the consolidation period. After the sacrification, radiologically bone mineral density, new bone formation, new fibrous tissue, and new vessel formation were analyzed using unbiased stereological methods.

RESULTS

It was found a statistically significant difference between the study groups and control group in the bone mineral density measurements and the highest values were in the ESWT1000 group. In terms of stereological analysis, there was a significant difference between the study groups and control group (P = 0.00). The new capillary volume was highest in the E1000 group. Additionally, significant differences were found in point of the capillary volumes between the groups control and ESWT500 (P = 0.001), control and ESWT1000 (P = 0.000), ESWT500 and ESWT1000 (P = 0.040), respectively.

CONCLUSIONS

A total of 1000 impulses ESWT may induce the growth factors to enhance the newly formed bone regeneration.

Influence of extracorporeal shock wave therapy (ESWT) on bone turnover markers in organisms with normal and low bone mineral density during fracture healing: a randomized clinical trial

Background: Low bone mineral density (BMD) leads to metaphyseal fractures, which are considered of delayed, qualitatively reduced healing resulting in prolonged care phases and increased socioeconomic costs. Extracorporeal shockwave therapy (ESWT) is already approved to support bone healing of pseudarthrosis and delayed unions. With this study, we examined its influence on bone turnover markers (BTM) during fracture healing in patients with low and normal BMD.

Methods: Within a period of 2 years, patients with a metaphyseal fracture of the distal radius or the proximal humerus, requiring surgical osteosynthesis were included into the study. Patients were randomized within their fracture groups whether they received ESWT after surgery or not. ESWT was applied once after surgery with an energy flux density (EFD) of 0.55 mJ/mm² à 3000 shockwaves. In addition, serum levels of vitamin D3, parathyroid hormone (iPTH), bone alkaline phosphatase (BAP), c-telopeptide of type-I-collagen (β-CTX) and serum band 5 tartrate-resistant acid phosphate (TRAP5b) were determined before surgery and post-operatively in week 1, 4, 8, 52. T-score levels as an indicator of the BMD were measured with dual-energy X-ray absorptiometry (DXA).

Results: 49 patients (40 females, 9 males; mean age 62 years) with fractures of the metaphyseal distal radius (n=25) or the proximal humerus (n=24) were included in the study. The follow-up time was one year. 24 of them were diagnosed of having low BMD, whereas 25 had a normal BMD. During follow-up time serum levels of bone turnover markers, as well as vitamin D3 and iPTH, showed no significant changes; however, ESWT approaches the decreased serum levels of patients with low BMD to the level of healthy organisms.

Conclusions: ESWT as treatment option of fractures in patients with low BMD can lead to an equilibration of levels of bone turnover markers to the levels of patients with normal BMD.

Optimization of screw fixation in rat bone with extracorporeal shock waves

Screw fixation in osteoporotic patients is becoming an increasing problem in orthopaedic surgery as deterioration of cortical and cancellous bone hamper biomechanical stability and screw fixation. This might result in delayed weight-bearing or failure of instrumentation. We hypothesized that local peri-operative shock wave treatment can optimize osseointegration and subsequent screw fixation. In eight female Wistar rats, two cancellous and two cortical bone screws were implanted in both femora and tibiae. Immediately after implantation, 3.000 unfocused extracorporeal shock waves (energy flux density 0.3 mJ/mm² ) were applied to one side. The other side served as non-treated internal control. Evaluation of osseointegration was performed after 4 weeks with the use of microCT scanning, histology with fluorochrome labeling, and pull-out tests of the screws. Four weeks after extracorporeal shock wave treatment, treated legs exhibited increased bone formation and screw fixation around cortical screws as compared to the control legs. This was corroborated by an increased pull-out of the shock wave treated cortical screws. The cancellous bone screws appeared not to be sensitive for shock wave treatment. Formation of neocortices after shock wave therapy was observed in three of eight animals. Furthermore, de novo bone formation in the bone marrow was observed in some animals. The current study showed bone formation and improved screw fixation as a result of shock wave therapy. New bone was also formed at locations remote from the screws, hence, not contributing to screw fixation. Further, research is warranted to make shock wave therapy tailor-made for fracture fixation. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:76-84, 2018.

Low-energy extracorporeal shockwave therapy (ESWT) improves metaphyseal fracture healing in an osteoporotic rat model

Purpose

As result of the current demographic changes, osteoporosis and osteoporotic fractures are becoming an increasing social and economic burden. In this experimental study, extracorporeal shock wave therapy (ESWT), was evaluated as a treatment option for the improvement of osteoporotic fracture healing.

Methods

A well-established fracture model in the metaphyseal tibia in the osteoporotic rat was used. 132 animals were divided into 11 groups, with 12 animals each, consisting of one sham-operated group and 10 ovariectomized (osteoporotic) groups, of which 9 received ESWT treatment. Different energy flux intensities (0.15 mJ/mm², 0.35 mJ/mm², or 0.55 mJ/mm²) as well as different numbers of ESWT applications (once, three times, or five times throughout the 35-day healing period) were applied to the osteoporotic fractures. Fracture healing was investigated quantitatively and qualitatively using micro-CT imaging, quantitative real-time polymerase chain reaction (qRT-PCR) analysis, histomorphometric analysis and biomechanical analysis.

Results

The results of this study show a qualitative and quantitative improvement in the osteoporotic fracture healing under low-energy (energy flux intensity: 0,15 mJ/mm²) ESWT and with fewer treatment applications per healing period.

Conclusion

In conclusion, low-energy ESWT seems to exhibit a beneficial effect on the healing of osteoporotic fractures, leading to improved biomechanical properties, enhanced callus-quantity and -quality, and an increase in the expression of bone specific transcription factors. The results suggest that low-energy ESWT, as main treatment or as adjunctive treatment in addition to a surgical intervention, may prove to be an effective, simple to use, and cost-efficient option for the qualitative and quantitative improvement of osteoporotic fracture healing.

Effects of Roughly Focused Extracorporeal Shock Waves Therapy on the Expressions of Bone Morphogenetic Protein-2 and Osteoprotegerin in Osteoporotic Fracture in Rats

BACKGROUND

Roughly focused extracorporeal shock waves therapy (ESWT) is characterized by a wide focal area, a large therapy zone, easy positioning, and less pain during treatment. The purpose of this study was to investigate the effects of roughly focused ESWT on the expression of osteoprotegerin (OPG) and bone morphogenetic protein-2 (BMP-2) in osteoporotic fractures in rats.

METHODS

Seventy-two female Sprague-Dawley (SD) rats, 3 months old, were divided into sham-operated group (n = 6) and an ovariectomized (OVX) group (n = 66). Sixty OVX SD rats were used as a model of double proximal tibial osteotomy and inner fixation. The osteotomy site in the left tibia was treated with roughly focused ESWT once at an energy density of 0.26 mJ/mm2, 60 doses/min, and 2000 pact quantities. The contralateral right tibia was left untreated and served as a control. Expression of OPG and BMP-2 in the callus of the osteoporotic fracture area was assessed using immunohistochemistry, real-time polymerase chain reaction (PCR), and Western blotting analysis.

RESULTS

Bone mineral density (BMD) at the proximal tibia, femur, and L5 spine was significantly reduced after ovariectomy. BMD of proximal tibia was 12.9% less in the OVX group than that in the sham-operated group. Meanwhile, bilateral oophorectomy resulted in a lower trabecular bone volume fraction (BV/TV) in the proximal tibia of the sham-OVX animals. Three months after bilateral oophorectomy, BV/TV was 14.29% of baseline BV/TV in OVX legs versus 45.91% in the sham-OVX legs (P < 0.001). These data showed that the SD rats became a suitable model of osteoporosis, 3 months after they were OVX. Immunohistochemical analysis showed higher levels of BMP-2 and OPG expression in the treatment group than those in the control group. Compared with the contralateral controls, decreased expression of OPG and BMP-2 at 3 days after roughly focused ESWT, followed by a later increase at 7 days, was indicated by real-time PCR and Western blotting analysis. The OPG messenger RNA (mRNA) expression levels peaked at 6 weeks after the shock wave treatment, paired with a much earlier (at 4 weeks) increase of BMP-2, and declined close to normal at 8 weeks.

CONCLUSIONS

Roughly focused ESWT may promote the expression of OPG and BMP-2 in the osteoporotic fracture area in rats. BMP-2 and OPG may act synergistically and may lead to a significant enhancement of bone formation and remodeling.

Extracorporeal shock waves alone or combined with raloxifene promote bone formation and suppress resorption in ovariectomized rats

Osteoporosis is a metabolic skeletal disease characterized by an imbalance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation. We examined the beneficial effect of shock waves (SW) alone or in combination with raloxifene (RAL) on bone loss in ovariectomized rats (OVX). Sixteen weeks after surgery, OVX were treated for five weeks with SW at the antero-lateral side of the right hind leg, one session weekly, at 3 Hz (EFD of 0.33 mJ/mm²), or with RAL (5 mg/kg/die, per os) or with SW+RAL. Sera, femurs, tibiae and vertebrae were sampled for following biochemical and histological analysis. SW, alone or combined with RAL, prevented femur weight reduction and the deterioration of trabecular microarchitecture both in femur and vertebrae. All treatments increased Speed of Sound (SoS) values, improving bone mineral density, altered by OVX. Serum parameters involved in bone remodeling (alkaline phosphatase, receptor activator of nuclear factor kappa-B ligand, osteoprotegerin) and osteoblast proliferation (PTH), altered by ovariectomy, were restored by SW and RAL alone or in combination. In tibiae, SW+RAL significantly reduced cathepsin k and TNF-α levels, indicating the inhibition of osteoclast activity, while all treatments significantly increased runt-related transcription factor 2 and bone morphogenetic-2 expression, suggesting an increase in osteoblastogenic activity. Finally, in bone marrow from tibiae, SW or RAL reduced PPARγ and adiponectin transcription, indicating a shift of mesenchymal cells toward osteoblastogenesis, without showing a synergistic effect. Our data indicate SW therapy, alone and in combination with raloxifene, as an innovative strategy to limit the hypoestrogenic bone loss, restoring the balance between bone formation and resorption.

Extracorporeal Shock Wave Therapy Is Effective in the Treatment of Bone Marrow Edema of the Medial Compartment of the Knee: A Comparative Study

OBJECTIVE

To test the hypothesis that shock wave therapy can produce a statistically significant improvement in symptoms and imaging features of the knee bone marrow edema syndrome (BMES) within 6 months of treatment.

SUBJECTS AND METHODS

Eighty-six consecutive patients suffering from BMES of the medial compartment of the knee were prescribed a course of high-energy extracorporeal shock wave therapy (ESWT) and clinically followed up at 3 and 6 months and finally from 14 to approximately 18 months after treatment. Thirty-one patients were unable to undergo ESWT but returned for the 6-month and final follow-up; these were referred to as the conservative (control) group, while the other 55 patients constituted the ESWT group. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Visual Analog Scale (VAS) score of each patient were calculated at every follow-up. The BME area was assessed using magnetic resonance imaging before treatment and at the 6-month follow-up.

RESULTS

Statistically significant improvements were observed in clinical scores and in the BME area for both the ESWT and the control group (p < 0.05). The improvements in the ESWT group were statistically better in all parameters compared with the control group: the ESWT group had a reduction in the BME area of 86% versus 41% in the control group, the VAS pain score improved by 88% in the ESWT group versus 42% in the control group, and the WOMAC score improved by 65% in the ESWT group versus 22% in the control group. Clinical scores were significantly better for patients with medial tibial lesions in the ESWT group.

CONCLUSION

In this study, ESWT reduced pain and the BME area in the knee, with significant clinical improvement noticed 3 months after treatment.

Triamcinolone acetonide activates an anti-inflammatory and folate receptor-positive macrophage that prevents osteophytosis in vivo

Introduction

Triamcinolone acetonide (TA) is used for osteoarthritis management to reduce pain, and pre-clinical studies have shown that TA limits osteophyte formation. Osteophyte formation is known to be facilitated by synovial macrophage activation. TA injections might influence macrophage activation and subsequently reduce osteophytosis. Although widely applied in clinical care, the mechanism through which TA exerts this effect remains unknown. In this animal study, we investigated the in vivo effects of TA injections on macrophage activation, osteophyte development and joint degeneration. Furthermore, in vitro macrophage differentiation experiments were conducted to further explain working mechanisms of TA effects found in vivo.

Methods

Osteoarthritis was induced in rat knees using papain injections and a running protocol. Untreated and TA-treated animals were longitudinally monitored for 12 weeks with in vivo micro–computed tomography (μCT) to measure subchondral bone changes. Synovial macrophage activation was measured in vivo using folate receptor β (FRβ)-targeted single-photon emission computed tomography/computed tomography. Articular cartilage was analyzed at 6 and 12 weeks with ex vivo contrast-enhanced μCT and histology. To further explain the outcomes of our in vivo study, TA on macrophages was also studied in vitro. These cultured macrophages were either M1- or M2-activated, and they were analyzed using fluorescence-activated cell sorting for CD163 and FRβ expression as well as for messenger RNA (mRNA) expression of interleukin (IL)-10.

Results

Our in vivo study showed that intra-articular injections with TA strongly enhanced FRβ⁺ macrophage activation. Despite stimulated macrophage activation, osteophyte formation was fully prevented. There was no beneficial effect of TA against cartilage degradation or subchondral bone sclerosis. In vitro macrophage cultures showed that TA strongly induced monocyte differentiation towards CD163⁺ and FRβ⁺ macrophages. Furthermore, TA-stimulated M2 macrophages showed enhanced IL-10 expression at the mRNA level.

Conclusions

TA injections potently induce a CD163⁺- and FRβ⁺-activated macrophage with anti-inflammatory characteristics such as reduced IL-10 production in vitro and lack of osteophytosis in vivo.

Inhibited osteoclastic bone resorption through alendronate treatment in rats reduces severe osteoarthritis progression

Osteoarthritis (OA) is a non-rheumatoid joint disease characterized by progressive degeneration of extra-cellular cartilage matrix (ECM), enhanced subchondral bone remodeling, osteophyte formation and synovial thickening. Alendronate (ALN) is a potent inhibitor of osteoclastic bone resorption and results in reduced bone remodeling. This study investigated the effects of pre-emptive use of ALN on OA related osteoclastic subchondral bone resorption in an in vivo rat model for severe OA. Using multi-modality imaging we measured effects of ALN treatment within cartilage and synovium. Severe osteoarthritis was induced in left rat knees using papain injections in combination with a moderate running protocol. Twenty rats were treated with subcutaneous ALN injections and compared to twenty untreated controls. Animals were longitudinally monitored for 12weeks with in vivo μCT to measure subchondral bone changes and SPECT/CT to determine synovial macrophage activation using a folate-based radiotracer. Articular cartilage was analyzed at 6 and 12weeks with ex vivo contrast enhanced μCT and histology to measure sulfated-glycosaminoglycan (sGAG) content and cartilage thickness. ALN treatment successfully inhibited subchondral bone remodeling. As a result we found less subchondral plate porosity and reduced osteophytosis. ALN treatment did not reduce subchondral sclerosis. However, after the OA induction phase, ALN treatment protected cartilage ECM from degradation and reduced synovial macrophage activation. Surprisingly, ALN treatment also improved sGAG content of tibia cartilage in healthy joints. Our data was consistent with the hypothesis that osteoclastic bone resorption might play an important role in OA and may be a driving force for progression of the disease. However, our study suggest that this effect might not solely be effects on osteoclastic activity, since ALN treatment also influenced macrophage functioning. Additionally, ALN treatment and physical activity exercised a positive effect in healthy control joints, which increased cartilage sGAG content. More research on this topic might lead to novel insights as to improve cartilage quality.

Electromagnetic fields do not affect bone micro-architecture in osteoporotic rats

Objectives

Electromagnetic fields (EMF) are widely used in musculoskeletal disorders. There are indications that EMF might also be effective in the treatment of osteoporosis. To justify clinical follow-up experiments, we examined the effects of EMF on bone micro-architectural changes in osteoporotic and healthy rats. Moreover, we tested the effects of EMF on fracture healing.

Methods

EMF (20 Gauss) was examined in rats (aged 20 weeks), which underwent an ovariectomy (OVX; n = 8) or sham-ovariectomy (sham-OVX; n = 8). As a putative positive control, all rats received bilateral fibular osteotomies to examine the effects on fracture healing. Treatment was applied to one proximal lower leg (three hours a day, five days a week); the lower leg was not treated and served as a control. Bone architectural changes of the proximal tibia and bone formation around the osteotomy were evaluated using in vivo microCT scans at start of treatment and after three and six weeks.

Results

In both OVX and sham-OVX groups, EMF did not result in cancellous or cortical bone changes during follow-up. Moreover, EMF did not affect the amount of mineralised callus volume around the fibular osteotomy.

Conclusions

In this study we were unable to reproduce the strong beneficial findings reported by others. This might indicate that EMF treatment is very sensitive to the specific set-up, which would be a serious hindrance for clinical use. No evidence was found that EMF treatment can influence bone mass for the benefit of osteoporotic patients.

Cite this article: Bone Joint Res 2014;3:230–5.

Soft-focused extracorporeal shock waves increase the expression of tendon-specific markers and the release of anti-inflammatory cytokines in an adherent culture model of primary human tendon cells

Focused extracorporeal shock waves have been found to upregulate the expression of collagen and to initiate cell proliferation in healthy tenocytes and to positively affect the metabolism of tendons, promoting the healing process. Recently, soft-focused extracorporeal shock waves have also been found to have a significant effect on tissue regeneration. However, very few in vitro reports have dealt with the application of this type of shock wave to cells, and in particular, no previous studies have investigated the response of tendon cells to this impulse. We devised an original model to investigate the in vitro effects of soft-focused shock waves on a heterogeneous population of human resident tendon cells in adherent monolayer culture. Our results indicate that soft-focused extracorporeal shock wave treatment (0.17 mJ/mm(2)) is able to induce positive modulation of cell viability, proliferation and tendon-specific marker expression, as well as release of anti-inflammatory cytokines. This could prefigure a new rationale for routine employment of soft-focused shock waves to treat the failed healing status that distinguishes tendinopathies.

FK506 protects against articular cartilage collagenous extra-cellular matrix degradation

OBJECTIVE

Osteoarthritis (OA) is a non-rheumatologic joint disease characterized by progressive degeneration of the cartilage extra-cellular matrix (ECM), enhanced subchondral bone remodeling, activation of synovial macrophages and osteophyte growth. Inhibition of calcineurin (Cn) activity through tacrolimus (FK506) in in vitro monolayer chondrocytes exerts positive effects on ECM marker expression. This study therefore investigated the effects of FK506 on anabolic and catabolic markers of osteoarthritic chondrocytes in 2D and 3D in vitro cultures, and its therapeutic effects in an in vivo rat model of OA.

METHODS

Effects of high and low doses of FK506 on anabolic (QPCR/histochemistry) and catabolic (QPCR) markers were evaluated in vitro on isolated (2D) and ECM-embedded chondrocytes (explants, 3D pellets). Severe cartilage damage was induced unilaterally in rat knees using papain injections in combination with a moderate running protocol. Twenty rats were treated with FK506 orally and compared to twenty untreated controls. Subchondral cortical and trabecular bone changes (longitudinal microCT) and macrophage activation (SPECT/CT) were measured. Articular cartilage was analyzed ex vivo using contrast enhanced microCT and histology.

RESULTS

FK506 treatment of osteoarthritic chondrocytes in vitro induced anabolic (mainly collagens) and reduced catabolic ECM marker expression. In line with this, FK506 treatment clearly protected ECM integrity in vivo by markedly decreasing subchondral sclerosis, less development of subchondral pores, depletion of synovial macrophage activation and lower osteophyte growth.

CONCLUSION

FK506 protected cartilage matrix integrity in vitro and in vivo. Additionally, FK506 treatment in vivo reduced OA-like responses in different articular joint tissues and thereby makes Cn an interesting target for therapeutic intervention of OA.

Characterization of the shock pulse-induced cavitation bubble activities recorded by an optical fiber hydrophone

A shock pressure pulse used in an extracorporeal shock wave treatment has a large negative pressure (<-5 MPa) which can produce cavitation. Cavitation cannot be measured easily, but may have known therapeutic effects. This study considers the signal recorded for several hundred microseconds using an optical hydrophone submerged in water at the focus of shock pressure field. The signal is characterized by shock pulse followed by a long tail after several microseconds; this signal is regarded as a cavitation-related signal (CRS). An experimental investigation of the CRS was conducted in the shock pressure field produced in water using an optical hydrophone (FOPH2000, RP Acoustics, Germany). The CRS was found to contain characteristic information about the shock pulse-induced cavitation. The first and second collapse times (t1 and t2) were identified in the CRS. The collapse time delay (tc = t2 - t1) increased with the driving shock pressures. The signal amplitude integrated for time from t1 to t2 was highly correlated with tc (adjusted R(2) = 0.990). This finding suggests that a single optical hydrophone can be used to measure shock pulse and to characterize shock pulse-induced cavitation.

Extracorporeal shock wave therapy in musculoskeletal disorders: a review

Regenerative therapy is one of the most challenging and intriguing branches of modern medicine. Basic research has demonstrated the effectiveness of extracorporeal shockwaves (ESWT) in stimulating biological activities that involve intra-cell and cell-matrix interactions. These interactions are at the basis of the current clinical applications, and open the horizons to new applications in tissue regeneration. It is also feasible that shock waves could be used to treat various orthopaedic pathologies, removing the need for surgery. However, suitable translational studies need to be performed before ESWT can become a valid alternative to surgery.

Unfocused extracorporeal shock waves induce anabolic effects in osteoporotic rats

Unfocused extracorporeal shock waves (UESW) have been shown to have an anabolic effect on bone mass. Therefore we investigated the effects of UESW on bone in osteoporotic rats with and without anti-resorptive treatment. Twenty-week-old rats were ovariectomized (n = 27). One group was treated with saline and another group with Alendronate (ALN) 2.4 µg/kg, 3×/week. UESW were applied 2 weeks after ovariectomy. Thousand UESW were applied to one hind leg, the contra-lateral hind leg was not treated and served as control. With the use of in vivo micro-CT scanning it was shown that in saline treated rats trabecular bone volume fraction (BV/TV) was higher at 2 weeks follow-up in UESW treated legs compared to control legs. However, at 4 and 10 weeks no difference was found. In ALN treated animals UESW led to a pronounced anabolic response resulting in an increase in BV/TV at all time-points. Furthermore, UESW resulted in increased cortical volume (CtV), higher trabecular connectivity and, more plate-like and thicker trabeculae. Biomechanical testing showed that UESW lead to a higher maximum force before failure and higher stiffness in all treatment groups. With histology abundant areas of intramembranous bone formation along the periosteal cortex and within the bone marrow were observed. In conclusion this study shows promising results for the use of UESW in the treatment of osteoporosis, especially when this treatment is combined with an anti-resorptive treatment.

Clinical application of extracorporeal shock wave therapy in orthopedics: focused versus unfocused shock waves

For the past decade extracorporeal shock wave therapy has been applied to a wide range of musculoskeletal disorders. The many promising results and the introduction of shock wave generators that are less expensive and easier to handle has added to the growing interest. Based on their nature of propagation, shock waves can be divided into two types: focused and unfocused. Although several physical differences between these different types of shock waves have been described, very little is known about the clinical outcome using these different modalities. The aim of the present review is to investigate differences in outcome in select orthopaedic applications using focused and unfocused shock waves.

Needleless vaccine delivery using micro-shock waves

Shock waves are one of the most efficient mechanisms of energy dissipation observed in nature. In this study, utilizing the instantaneous mechanical impulse generated behind a micro-shock wave during a controlled explosion, a novel nonintrusive needleless vaccine delivery system has been developed. It is well-known that antigens in the epidermis are efficiently presented by resident Langerhans cells, eliciting the requisite immune response, making them a good target for vaccine delivery. Unfortunately, needle-free devices for epidermal delivery have inherent problems from the perspective of the safety and comfort of the patient. The penetration depth of less than 100 μm in the skin can elicit higher immune response without any pain. Here we show the efficient utilization of our needleless device (that uses micro-shock waves) for vaccination. The production of liquid jet was confirmed by high-speed microscopy, and the penetration in acrylamide gel and mouse skin was observed by confocal microscopy. Salmonella enterica serovar Typhimurium vaccine strain pmrG-HM-D (DV-STM-07) was delivered using our device in the murine salmonellosis model, and the effectiveness of the delivery system for vaccination was compared with other routes of vaccination. Vaccination using our device elicits better protection and an IgG response even at a lower vaccine dose (10-fold less) compared to other routes of vaccination. We anticipate that our novel method can be utilized for effective, cheap, and safe vaccination in the near future.

Low-intensity ultrasound stimulation prevents osteoporotic bone loss in young adult ovariectomized mice

Osteoporosis is a disease characterized by low bone mass, increased bone fragility, and a greater risk for bone fracture. Currently, pharmacological intervention can generally aid in the prevention and treatment of osteoporosis, but these therapies are often accompanied by undesirable side effects. Therefore, alternative therapies that minimize side effects are necessary. Biophysical stimuli, especially low-intensity ultrasound stimulation (LIUS), may be potential alternatives to drug-based therapies for osteoporosis. Hence, we sought to address whether LIUS therapy can effectively prevent or treat osteoporotic bone loss induced by estrogen deficiency. LIUS (1.5 MHz frequency, 1.0 kHz pulse repetition on frequency, 30 mW/cm(2) intensity, 200 µs pulse length) was applied to right tibiae of eight 14-week-old ovariectomized virgin ICR female mice for 20 min per day, 5 days per week, over a 6-week period. Changes in 3D structural bone characteristics were detected using in vivo micro-computed tomography. Left tibiae served as controls. Structural characteristics including bone volume/tissue volume, trabecular number, trabecular bone pattern factor, and mean polar moment inertia were significantly enhanced 6 weeks after LIUS compared to the control, nonstimulated group (p < 0.05). In particular, the bone volume/tissue volume in the region exposed directly to LIUS was significantly higher in the treated group (p < 0.05). These findings indicate that new bone formation may be activated or that bone structure may be maintained by LIUS, and that LIUS may be effective for preventing estrogen deficiency-induced bone loss.