Shock wave application enhances pertussis toxin protein-sensitive bone formation of segmental femoral defect in rats

Therapeutic implications of extracorporeal shock waves in burn wound healing

Burns are a common type of trauma that seriously affect not only the physical health, but also the mental health and quality of life of the patient. Extracorporeal shock wave therapy (ESWT) is an emerging treatment that has been used in clinical treatment. It has many advantages, including safety, non-invasiveness, efficiency, short treatment duration, fewer complications, and relatively low prices. In clinical settings, ESWT has played an important role in the healing process of burns and the prevention of sequelae. This article reviews the history of ESWT, the mechanism of ESWT to promote burn healing, and the application of ESWT in burns. Current status of ESWT treatment for burns as well as future perspectives for research have been summarized and proposed. However, patients with burns cannot be considered recovered when the wounds have healed, we need some new technology to adjust to the challenges of the future.

The effects and underlying mechanism of extracorporeal shockwave therapy on fracture healing

The clinical efficacy of ESWT in treating bone non union has been widely recognized, but the biological mechanism of ESWT promoting bone non union healing is still unclear. ESWT can make old callus micro fracture through mechanical conduction, form subperiosteal hematoma, promote the release of bioactive factors, reactivate the fracture healing mechanism, rebalance the activities of osteoblasts and osteoclast, promote the angiogenesis of fracture site, and accelerate the healing of bone nonunion.Over recent years, great efforts have been made by both scientists and clinicians to explore the underlying mechanism behind the healing effect of ESWT on bone fractures. In this review, we introduced the growth factors during osteogenesis induced by ESWT hoping to provide new insights in the clinical use of ESWT.

Extracorporeal shock wave therapy for shoulder pain after stroke: A systematic review and meta-analysis

OBJECTIVE

To systematically review the effects of extracorporeal shock wave therapy (ESWT) for shoulder pain after stroke.

DATA SOURCES

A systematic review of Cochrane Central Register of Controlled Trials (CENTRAL), Embase, PubMed, Web of Science, CNKI, SinoMed, WanFang Data, VIP, and ClinicalTrials.gov from the establishment of the database to 20 December 2022 was carried out.

REVIEW METHODS

The bibliography was screened to identify randomized controlled trials (RCTs) that applied extracorporeal shock waves to shoulder pain after stroke. Two researchers independently searched, screened, and extracted data from each database according to the search strategy and resolved any disagreements through negotiation.

RESULTS

A total of 18 RCTs were included (1248 individuals). Meta-analysis showed that the ESWT group had better visual analogue scale (VAS) scores (mean difference (MD) =  - 1.19, 95% confidence interval (CI) [ - 1.43, - 0.95], p < 0.00001), Fugl-Meyer assessment upper extremity scale (FMA-UE) scores (MD = 6.25, 95% CI [4.64, 7.87], p < 0.00001), active range of motion (AROM) assessment (MD = 11.28, 95% CI [5.26, 17.30], p = 0.0002), and functional comprehensive assessment (FCA) scores (MD = 5.47, 95% CI [4.45, 6.49], p < 0.00001) comparative to the control group; no statistical significance in Constant-Murley score (CMS) (MD = 0.98, 95% CI [ - 11.05, 13.02], p = 0.87) and descriptive analysis of modified Barthel Index (MBI) only.

CONCLUSION

The ESWT improves pain levels, motor function, active mobility, comprehensive function of shoulder, and activities of daily living (ADL) better than conventional treatment in patients with shoulder pain after stroke.

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.

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.

Extracorporeal shock wave therapy mechanisms in musculoskeletal regenerative medicine

Extracorporeal shockwave therapy (ESWT) is a popular non-invasive therapeutic modality in the medical field for the treatment of numerous musculoskeletal disorders. This technique first emerged around the 1980s as extracorporeal shockwave lithotripsy and has been studied since then for its application towards orthopedics and traumatology. ESWT works by the emission of acoustic waves (shockwaves) that carry energy and can propagate through tissues. Shockwaves can generate interstitial and extracellular responses, producing many beneficial effects such as: pain relief, vascularization, protein biosynthesis, cell proliferation, neuro and chondroprotection, and destruction of calcium deposits in musculoskeletal structures. The combination of these effects can lead to tissue regeneration and significant alleviation of pain, improving functional outcomes in injured tissue. Considering these facts, ESWT shows great potential as a useful regenerative medicine technique for the treatment of numerous musculoskeletal injuries.

Shockwave Therapy Associated With Eccentric Strengthening for Achilles Insertional Tendinopathy: A Prospective Study

Background. The usual initial treatment for insertional Achilles tendinopathy is nonsurgical. Yet there is no standard conservative treatment for Achilles insertional tendinopathy. Shockwave therapy (SWT) has become a reliable option for the management of this illness over the past years. The aim of this study is to report the effectiveness of low-energy SWT associated with an eccentric strengthening protocol in 19 consecutive patients. Methods. This is a prospective study with 19 patients aged between 26 and 72 years diagnosed with insertional Achilles tendinopathy. The protocol consisted of SWT associated with eccentric exercises for 12 weeks. All patients were evaluated on the first day and after 24 weeks (final follow-up) with the Victorian Institute of Sports Assessment-Achilles (VISA-A) score, visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) questionnaire, and by algometry. At the last follow-up, patients were also assessed for adherence to the protocol, complications and final outcome (in their perception as success or fail). Results and Conclusion. Fifteen (79%) patients were fully adherent to the Alfredson protocol, and 13 (68%) patients considered the treatment protocol successful. At the last evaluation, patients demanded higher pressure on calcaneus to trigger pain (algometry 1), reported less pain when the algometer was applied with 3 kg (algometry 2), had less global pain (VAS), and had higher AOFAS and VISA-A scores. This study evidences that eccentric loading associated with SWT can dramatically improve patients' symptoms. We can conclude that eccentric loading associated with SWT is an effective treatment for Achilles insertional tendinopathy. Levels of Evidence: Therapeutic, Level III: Prospective cohort.

Rehabilitation treatment of spastic cerebral palsy with radial extracorporeal shock wave therapy and rehabilitation therapy

This aims to investigate the effect of combined use of radial extracorporeal shock wave therapy (rESWT) and conventional rehabilitation therapy on postoperative rehabilitation of children with spastic cerebral palsy.Children with spastic cerebral palsy 6 weeks after multistage surgery were randomly divided into treatment group (received rESWT and conventional rehabilitation therapy) and control group (received conventional rehabilitation only). Before treatment, 2 weeks and 1 month after treatment, the Gross Motor Function Measure (GMFM), modified Ashworth Scale (MAS) of the hamstrings and triceps, plantar area and plantar pressure were examined for efficacy assessment.A total of 82 children with spastic cerebral palsy were recruited, including 43 children in treatment group and 39 children in control group. There was no significant difference in the age, MAS score, and GMFM score between the 2 groups before treatment. There were statistically significant differences between the 2 groups at 2 weeks and 4 weeks after treatment, including the MAS score, GMFM score, plantar area and plantar pressure (P < .05). Within groups, there were also significant differences at different times (P < .05).The rESWT combined with rehabilitation can quickly and effectively relieve paralysis of lower extremities, reduce the tension of hamstrings and calf muscles, relieve muscle spasm, and rapidly improve limb function in children with spastic cerebral palsy.

A review of the cellular and molecular effects of extracorporeal shockwave therapy

Extracorporeal shockwave therapy (ESWT) is a novel therapeutic modality and its use in promoting connective tissue repair and analgesic effect has been advocated in the literature. It is convenient, cost-effective, and has negligible complications; it therefore bypasses many of the problems associated with surgical interventions. This paper reviews the proposed mechanisms of action in promoting tissue repair and regeneration as well as analysing its efficacy providing an analgesic effect in clinical applications. Further research will be required to not only identify the underlying mechanisms more precisely, but will also be critical for ensuring consistency across the literature so that the most beneficial treatment protocol can be developed. Extracorporeal shockwave therapy stands as a promising alternative modality in promoting tissue repair.

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.

An Innovative Approach for Enhancing Bone Defect Healing Using PLGA Scaffolds Seeded with Extracorporeal-shock-wave-treated Bone Marrow Mesenchymal Stem Cells (BMSCs)

Although great efforts are being made using growth factors and gene therapy, the repair of bone defects remains a major challenge in modern medicine that has resulted in an increased burden on both healthcare and the economy. Emerging tissue engineering techniques that use of combination of biodegradable poly-lactic-co-glycolic acid (PLGA) and mesenchymal stem cells have shed light on improving bone defect healing; however, additional growth factors are also required with these methods. Therefore, the development of novel and cost-effective approaches is of great importance. Our in vitro results demonstrated that ESW treatment (10 kV, 500 pulses) has a stimulatory effect on the proliferation and osteogenic differentiation of bone marrow-derived MSCs (BMSCs). Histological and micro-CT results showed that PLGA scaffolds seeded with ESW-treated BMSCs produced more bone-like tissue with commitment to the osteogenic lineage when subcutaneously implanted in vivo, as compared to control group. Significantly greater bone formation with a faster mineral apposition rate inside the defect site was observed in the ESW group compared to control group. Biomechanical parameters, including ultimate load and stress at failure, improved over time and were superior to those of the control group. Taken together, this innovative approach shows significant potential in bone tissue regeneration.

A histomorphometric study of necrotic femoral head in rabbits treated with extracorporeal shock waves

[Purpose] This study aimed to determine the effectiveness and mechanisms of extracorporeal shock wave therapy in the treatment of femoral head osteonecrosis. [Subjects and Methods] Histomorphometric analysis of necrotic femoral head in rabbits treated with shock waves was performed. Bilateral osteonecrosis of femoral heads was induced with methylprednisolone and lipopolysaccharide in eight rabbits. The left limb (study side) received shock waves to the femoral head. The right limb (control side) received no shock waves. Biopsies of the femoral heads were performed at 12 weeks after shock wave therapy. [Results] Necrotic femoral heads treated with shock waves, compared with controls, had higher bone volume per tissue volume, trabecular thickness, trabecular number, osteoblast surface/bone surface, osteoid surface/bone surface, osteoid thickness, mineralizing surface/bone surface, mineralizing apposition rate, and bone formation rate. However, trabecular separation was lower in shock wave-treated femoral heads than in controls. Eroded surface/bone surface and osteoclast surface/bone surface did not differ significantly between groups. [Conclusion] The bone mass of necrotic femoral heads treated with shock waves increases. Extracorporeal shock wave may promote bone repair in necrotic femoral heads through the proliferation and activation of osteoblasts.

Shock wave therapy associated with eccentric strengthening versus isolated eccentric strengthening for Achilles insertional tendinopathy treatment: a double-blinded randomised clinical trial protocol

BACKGROUND

There is no consensus regarding the treatment of Achilles insertional tendinopathies. Eccentric training remains the main choice in the conservative treatment of this illness; however, the good results in the management of non-insertional Achilles tendinopathy were not replicated in the insertional condition. Low energy shock wave therapy has been described as an alternative to these patients, but has yet to be empirically tested.

HYPOTHESIS

Shock wave therapy, adjunctive to the eccentric strengthening protocol, will improve measures of pain and function.

DESIGN

Double blind, placebo-controlled, parallel groups, randomised clinical trial.

MATERIALS AND METHODS

93 patients with a diagnosis of chronic insertional tendinopathy, referred from primary or secondary healthcare services, will be assessed and enrolled in this study. They will be divided into two groups (randomised by sequentially numbered identical envelopes, which will be administered serially to participants), one containing the combination of low energy shock wave and eccentric exercises, as treatment and the other comprehending the exercises and the placebo treatment (an apparatus placed in the therapeutic head). The assessments will occur in 2, 4, 6, 12 and 24 weeks. Patients will be evaluated primarily by the Victorian Institute of Sport Assessment-Achilles questionnaire and secondarily by the visual analogue scale, Algometry, the American Orthopedic Foot and Ankle Society scale, the Foot and Ankle Outcome Score and the 12-item Short Form Health Survey. We will use comparison of two proportions via relative frequency analysis, the Pearson Correlation the χ² test and the analysis of variance for statistical analyses.

DISCUSSION

This study intends to demonstrate if the association of the eccentric exercise programme with the shock wave therapy can produce good results regarding the treatment of the Achilles insertional tendinopathy. In an attempt to prevent the high costs and complications associated with the surgical intervention, we will try to prove this combination as a viable therapeutic option in the conservative management of this prevalent condition. The strengths of the study are the design and the novelty of the combination of methods. The main limitation is the short follow-up course.

ETHICS AND DISSEMINATION

The study is registered in the Clinical Trials database (protocol number: 8094833648737701) and was approved by the University Ethics Committee (number: 1373481).

TRIAL REGISTRATION NUMBER

8094833648737701 (NCT02757664); Pre-results.

Prostaglandin E2 and Connexin 43 crosstalk in the osteogenesis induced by extracorporeal shockwave

As a type of mechanical stimulation, extracorporeal shockwave (ESW) has been widely used in the clinic to treat bone fracture delayed union and non-unions. A large number of studies have shown beneficial effects of ESW in promoting fracture healing by inducing bone regeneration; however, the underlying mechanisms remain unclear. ESW has been shown to induce the production of prostaglandin E2 (PGE2), which is essential for gap junction intercellular communication in response to mechanical stress. Among the 19 known gap junction subunits, connexin43 (Cx43) is the most prevalent for mediating the response of mechanical stress. However, to our knowledge, the effect of ESW on Cx43 expression has not been reported before. Herein, we propose that a crosstalk between PGE2 and Cx43 is involved in the enhancement of osteogenesis induced by ESW. We review the currently available data to propose an unrevealed, but important mechanism via which ESW treatment affects osteogenic differentiation of bone marrow stromal cells.

Focal Adhesion Kinase Signaling Mediated the Enhancement of Osteogenesis of Human Mesenchymal Stem Cells Induced by Extracorporeal Shockwave

Extracorporeal shockwave (ESW) has been shown of great potential in promoting the osteogenesis of bone marrow mesenchymal stem cells (BMSCs), but it is unknown whether this osteogenic promotion effect can also be achieved in other MSCs (i.e., tendon-derived stem cells (TDSCs) and adipose-derived stem cells (ADSCs)). In the current study, we aimed not only to compare the osteogenic effects of BMSCs induced by ESW to those of TDSCs and ADSCs; but also to investigate the underlying mechanisms. We show here that ESW (0.16 mj/mm(2)) significantly promoted the osteogenic differentiation in all the tested types of MSCs, accompanied with the downregulation of miR-138, but the activation of FAK, ERK1/2, and RUNX2. The enhancement of osteogenesis in these MSCs was consistently abolished when the cells were pretreated with one of the following conditions: overexpression of miR-138, FAK knockdown using specific siRNA, and U0126, implying that all of these elements are indispensable for mediating the effect of ESW. Moreover, our study provides converging genetic and molecular evidence that the miR-138-FAK-ERK1/2-RUNX2 machinery can be generally activated in ESW-preconditioned MSCs, suggesting that ESW may be a promising therapeutic strategy for the enhancement of osteogenesis of MSCs, regardless of their origins.

Radial extracorporeal shock wave therapy (rESWT) induces new bone formation in vivo: results of an animal study in rabbits

The aim of this study was to investigate if radial extracorporeal shock wave therapy (rESWT) induces new bone formation and to study the time course of ESWT-induced osteogenesis. A total of 4000 impulses of radial shock waves (0.16 mJ/mm²) were applied to one hind leg of 13 New Zealand white rabbits with the contralateral side used for control. Treatment was repeated after 7 days. Fluorochrome sequence labeling of new bone formation was performed by subcutaneous injection of tetracycline, calcein green, alizarin red and calcein blue. Animals were sacrificed 2 weeks (n = 4), 4 weeks (n = 4) and 6 weeks (n = 5) after the first rESWT and bone sections were analyzed by fluorescence microscopy. Deposits of fluorochromes were classified and analyzed for significance with the Fisher exact test. rESWT significantly increased new bone formation at all time points over the 6-week study period. Intensity of ossification reached a peak after 4 weeks and declined at the end of the study. New bone formation was significantly higher and persisted longer at the ventral cortex, which was located in the direction to the shock wave device, compared with the dorsal cortex, emphasizing the dose-dependent process of ESWT-induced osteogenesis. No traumata, such as hemorrhage, periosteal detachment or microfractures, were observed by histologic and radiologic assessment. This is the first study demonstrating low-energy radial shock waves to induce new bone formation in vivo. Based on our results, repetition of ESWT in 6-week intervals can be recommended. Application to bone regions at increased fracture risk (e.g., in osteoporosis) are possible clinical indications.

Extracorporeal shockwave-induced expression of lubricin in tendons and septa

Lubricin, a lubricating glycoprotein that facilitates tendon gliding, is upregulated by mechanical as well as biochemical stimuli, prompting this study of its induction by extracorporeal shockwave therapy (ESWT). The objective of this study was to characterize and quantify the effect of ESWT on lubricin expression in tendons and septa in a rat model. Hindlimbs of six rats were treated with low-dose ESWT and those of another six with high-dose ESWT, using contralateral limbs as controls. After 4 days, resected samples were processed for immunolocalization of lubricin using a purified monoclonal antibody. ESWT was found to increase lubricin expression in both low-dose and high-dose ESWT-treated tendons and also in septa. Lubricin expression generally increased with increasing dose of ESWT. Increased lubricin expression may contribute to the beneficial effects of ESWT in providing pain and symptom relief in musculoskeletal disorders by decreasing erosive wear.

Effects of zoledronic acid on healing of mandibular fractures: an experimental study in rabbits

PURPOSE

The purpose of the present study was to evaluate the effects of systemically administered zoledronic acid (ZA) on mandibular fracture healing in a rabbit model using radiodensitometric, biomechanical, histologic, and histomorphometric methods.

MATERIALS AND METHODS

A total of 36 skeletally mature male New Zealand white rabbits were used. The rabbits were randomly divided into 2 groups. A mandibular corpus fracture was created experimentally in all 36 rabbits. The experimental group was administered an intravenous, single dose of 0.1 mg/kg ZA, and the control group was administered only saline infusion during the procedure. All rabbits were sacrificed on the 21st postoperative day. Digital radiodensitometric analysis, a 3-point bending test, and histologic and histomorphometric examinations were performed on the harvested hemimandibles. The data were analyzed statistically.

RESULTS

Biomechanical testing data showed that ZA treatment resulted in a significant increase in the healed bone strength. This result was supported by the radiologic, histologic, and histomorphometric findings.

CONCLUSIONS

The results of the present study have revealed that systemic administration of ZA accelerates and improves the bone healing of mandibular fractures.

Extracorporeal shock wave therapy: current evidence

OBJECTIVES

The aim of this article is to provide a concise review of the basic science of extracorporeal shock wave therapy (ESWT) and to perform a systematic review of the literature for the use of ESWT in the treatment of fractures and delayed unions/nonunions.

DATA SOURCES

Articles in the English or German language were identified for the systematic review by searching PubMed-MEDLINE from 1966 until 2008, Cochrane Database of Systematic Reviews, Cochrane Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, and relevant meeting abstracts from 2007 to 2008. Moreover, the bibliographies of the identified articles were reviewed.

STUDY SELECTION

We included clinical outcome studies of ESWT in the treatment of fractures and delayed unions/nonunions. Reports with less than 10 patients were excluded. Nonunions after corrective osteotomies or arthrodeses were excluded.

DATA EXTRACTION

Sample size, level of evidence, definition of delayed union, definition of nonunion, time from injury to shock wave treatment, location of fracture, union rate, and complications were extracted from the identified articles.

DATA SYNTHESIS

Data of 924 patients undergoing ESWT for delayed union/nonunion were extracted from 10 studies. All articles were graded as level 4 studies. The overall union rate was 76% (95% confidence interval 73%-79%). The union rate was significantly higher in hypertrophic nonunions than in atrophic nonunions.

CONCLUSION

Data from level 4 studies suggest that shock wave therapy seems to stimulate the healing process in delayed unions/nonunions. However, further investigations are required.

The effects of shockwave on bone healing and systemic concentrations of nitric oxide (NO), TGF-beta1, VEGF and BMP-2 in long bone non-unions

This study investigated the effects of extracorporeal shockwave treatment (ESWT) on bone healing and the systemic concentrations of nitric oxide (NO), TGF-beta1, VEGF and BMP-2 in long bone non-unions. Forty-two patients with 42 established non-unions of the femur and tibia were enrolled in this study. Each long bone non-union was treated with 6000 impulses of shockwave at 28 kV in a single session. Ten milliliters of peripheral blood were obtained for measurements of serum NO level and osteogenic growth factors including TGF-beta1, VEGF and BMP-2; serum levels of calcium, alkaline phosphatase, calcitonin and parathyroid hormone before treatment and at 1 day, 1, 3 and 6 months after treatment. The evaluations for bone healing included clinical assessments and serial radiographic examinations. At 6 months, bony union was radiographically confirmed in 78.6%, and persistent non-union in 21.4%. Patients with bony union showed significantly higher serum NO level, TGF-beta1, VEGF and BMP-2 at 1 month after treatment as compared to patients with persistent non-union. Shockwave-promoted bone healing was associated with significant increases in serum NO level and osteogenic growth factors. The elevations of systemic concentration of NO level and the osteogenic factors may reflect a local stimulation of shockwave in bone healing in long bone non-unions.

Biological effects of extracorporeal shockwave in bone healing: a study in rabbits

INTRODUCTION

This study is an investigation of the biological effects of extracorporeal shockwave treatment (ESWT) on bone healing in a rabbit model.

MATERIALS AND METHODS

Sixteen 12-month-old New Zealand white rabbits with body weight ranging from 2.5 to 3.5 kg were used in the study. An intra-medullary pin was inserted retrograde into the femur canal. A closed fracture of the femur was created with a three-point bend method. The animals were randomly divided into the study group and the control group with eight rabbits in each group. The study group received shockwave treatment, whereas the control group did not. The animals were killed at 12 weeks, and a 5-cm long femur bone including the callus was harvested. The specimens were subjected to biomechanical study, histomorphological examination, and immunohistochemical analysis.

RESULTS

The shockwave group showed significantly better bone strength in biomechanical study, more cortical bone formation in histomorphological examination and higher number of neo-vessels and angiogenic and osteogenic growth markers including VEGF, eNOS, PCNA, and BMP-2 on immunohistochemical stains than the control group.

CONCLUSION

ESWT significantly improved bone healing after fracture of the femur in rabbit. ESWT promoted the formation of cortical bone what might have been associated with increased biomechanical results. ESWT-promoted bone healing was associated with increased neovascularization and up-regulation of angiogenic and osteogenic growth factors.

Extracorporeal Shock Wave Therapy Induces Alveolar Bone Regeneration

Periodontal inflammation with alveolar bone resorption is a hallmark of periodontitis. We hypothesized that extracorporeal shock wave therapy (ESWT) could promote the regeneration of alveolar bone following Porphyromonas gingivalis-induced periodontitis in rats. Rats were infected with P. gingivalis for 10 wks, which caused alveolar bone resorption. The rats were then treated with a single episode of 100, 300, or 1000 impulses of shock wave on both cheeks at energy levels 0.1 mJ/mm2. Alveolar bone levels were determined at 0, 3, 6, and 12 wks following ESWT and compared with those in untreated controls. Infected rats treated with 300 and 1000 impulses demonstrated significantly improved alveolar bone levels at 3 wks compared with untreated controls, and the improved levels remained for at least 6 wks in most rats. The results demonstrated effective regeneration of alveolar bone by ESWT and suggested that ESWT should be evaluated as an adjunct in the regeneration of periodontal tissues following periodontal disease. Abbreviations: ESWT, extracorporeal shock wave therapy; PCR, polymerase chain-reaction.

Upregulation of VEGF in subchondral bone of necrotic femoral heads in rabbits with use of extracorporeal shock waves

Extracorporeal shock wave treatment appears to be effective in patients with avascular necrosis of the femoral head. However, the pathway of biological events whereby this is accomplished has not been fully elucidated. The purpose of this study was to investigate the effect of extracorporeal shock waves on vascular endothelial growth factor (VEGF) expression in necrotic femoral heads of rabbits. VEGF expression was assessed by immunohistochemistry, quantitative real-time PCR, and Western blot analysis. The degree of angiogenesis was also assessed, as determined by the microvessel density (MVD), the assessment of which was based on CD31-expressing vessels. Bilateral avascular necrosis of femoral heads was induced with methylprednisolone and lipopolysaccharide in 30 New Zealand rabbits. The left limb (the study side) received shock wave therapy to the femoral head. The right limb (the control side) received no shock wave therapy. Biopsies of the femoral heads were performed at 1, 2, 4, 8, and 12 weeks. Western blot analysis and real-time PCR showed that shock wave therapy significantly increased VEGF protein and mRNA expression, respectively, in the subchondral bone of the treated necrotic femoral heads. Compared with the contralateral control without shock wave treatment, the VEGF mRNA expression levels increased to a peak at 2 weeks after the shock wave treatment and remained high for 8 weeks, then declined at 12 weeks, whereas the VEGF protein expression levels increased to a peak at 4 weeks after the shock wave treatment and remained high for 12 weeks. The immunostaining of VEGF was weak in the control group, and the immunoreactivity level in the shock-wave-treated group increased at 4 weeks and persisted for 12 weeks. The most intensive VEGF immunoreactivity was observed in the proliferative zone above the necrotic zone. At 4, 8, and 12 weeks after the shock wave treatment, MVD in subchondral bone from treated femoral heads was significantly higher than that in subchondral bone from untreated femoral heads. These data clearly show that extracorporeal shock waves can significantly upregulate the expression of VEGF. The upregulation of VEGF may play a role in inducing the ingrowth of neovascularization and in improving the blood supply to the femoral head.

Bone morphogenetic proteins and their antagonists

Skeletal homeostasis is determined by systemic hormones and local factors. Bone morphogenetic proteins (BMPs) are unique because they induce the commitment of mesenchymal cells toward cells of the osteoblastic lineage and also enhance the differentiated function of the osteoblast. BMP activities in bone are mediated through binding to specific cell surface receptors and through interactions with other growth factors. BMPs are required for skeletal development and maintenance of adult bone homeostasis, and play a role in fracture healing. BMPs signal by activating the mothers against decapentaplegic (Smad) and mitogen activated protein kinase (MAPK) pathways, and their actions are tempered by intracellular and extracellular proteins. The BMP antagonists block BMP signal transduction at multiple levels including pseudoreceptor, inhibitory intracellular binding proteins, and factors that induce BMP ubiquitination. A large number of extracellular proteins that bind BMPs and prevent their binding to signaling receptors have emerged. The extracellular antagonists are differentially expressed in cartilage and bone tissue and exhibit BMP antagonistic as well as additional activities. Both intracellular and extracellular antagonists are regulated by BMPs, indicating the existence of local feedback mechanisms to modulate BMP cellular activities.

Effects of Low-Intensity Pulsed Ultrasound on Healing of Mandibular Fractures: An Experimental Study in Rabbits

PURPOSE

Pulsed ultrasonic waves have been shown to accelerate fracture healing of the long bones. The aim of this study was to evaluate the effects of low-intensity pulsed ultrasound (LIPU) on healing of mandibular fractures.

MATERIALS AND METHODS

Thirty skeletally mature male New Zealand rabbits were used. Animals underwent unilateral mandibular osteotomy. The bone segments were repositioned and fixed with miniplates and miniscrews. Half of the animals received daily ultrasound treatment, 20 min/day, for 20 days. Ultrasound signals consisted of a 1.5-MHz pressure wave administered in pulses of 200 microsec with an average temporal and spatial intensity of 30 mW/cm2. Animals in the control group received sham application. All of the animals were killed on postoperative day 22. Three-point bending test, digital radiodensitometric analysis, and histologic and histomorphometric examinations were performed on the harvested hemimandibles. The data were statistically analyzed.

RESULTS

Biomechanical tests revealed significant improvement in the mechanical properties of the healing bone in the LIPU-treated group. This was supported by histologic and radiologic findings.

CONCLUSIONS

Results of this study suggest that LIPU improves the bone healing of mandibular fractures in rabbits.

Application of micro-CT assessment of 3-D bone microstructure in preclinical and clinical studies

As the mechanical competence of trabecular bone is a function of its apparent density and 3-D distribution, assessment of 3-D trabecular structural characteristics may improve our ability to understand the pathophysiology of osteoporosis, to test the efficacy of pharmaceutical intervention, and to estimate bone biomechanical properties. We have studied ovariectomy-induced osteopenia in rats and its treatment with agents such as estrogen and sodium fluoride. We have demonstrated that 3-D micro-computed tomography (microCT) can directly quantify mouse trabecular and cortical bone structure with an isotropic resolution of 6 microm(3). MicroCT is also useful for studying osteoporosis in mice and phenotypes of mice with gene manipulation, such as SHIP-knockout mice, which are severely osteoporotic due to increased numbers of hyperresorptive osteoclasts, PTHrP heterozygous-null mice, and mice with Zmpste24 deficiency. MicroCT can quantify osteogenesis in mouse Ilizarov leg-lengthening procedures, osteoconduction in a rat cranial defect model, and structural changes in arthritic rabbits, rats, and mice. In clinical studies, we evaluated longitudinal changes in the iliac crests. Paired bone biopsies from the same premenopausal and postmenopausal women showed the changes in 3-D trabecular structure, such as decreased trabecular thickness, shifting of trabecular model from platelike structure to rodlike structure, and decreased degree of anisotropy were remarkable. Treatment with PTH in postmenopausal women with osteoporosis significantly improved trabecular morphology with a shift toward a more platelike structure, increased trabecular connectivity density, and increased cortical thickness. Paired bone biopsy specimens from the iliac crest in postmenopausal women with osteoporosis before and an average of 2 years after beginning of estrogen replacement therapy demonstrated that posttreatment biopsies showed a significant change in the ratio of plates to rods and statistically insignificant changes in other 3-D trabecular parameters. Thus, microCT can characterize 3-D structure of various animal models, and the longitudinal changes in 3-D bone microarchitectural integrity that deteriorates in the transmenopausal period, is preserved with HRT, and is improved with PTH treatment in postmenopausal women.

Clinical management of osteoporosis in women with a history of breast carcinoma

Osteoporosis is a skeletal disorder that is characterized by low bone mass and compromised bone strength. Fractures are the clinically important consequence of osteoporosis and result not only in disability but also in excess mortality. Women who have a history of breast carcinoma may represent a unique population for whom screening and treatment for osteoporosis should be modified. A review of the English literature was performed that included original, review, consensus, and statement articles that were identified through Medline or National Institutes of Health-related links. According to the literature, osteoporosis constitutes a major public health problem. Approximately 55% of the U.S. population > or = 50 years of age has low bone mass (osteopenia or osteoporosis). Annually, > 200,000 women in the U.S. are diagnosed with breast carcinoma. Due to the high prevalence rates of both low bone mass and breast carcinoma in women, these two diseases commonly coexist in the same individuals. Women with a history of breast carcinoma may be at increased risk of developing bone loss and fragility fractures as a consequence of antineoplastic therapies. The majority of women treated for early-stage breast carcinoma do not develop recurrences, as a result of recent advances in therapy. Ensuring the diagnosis, prevention, and treatment of long-term toxicities and comorbid conditions like osteoporosis in breast carcinoma survivors is a serious concern and is of increasing importance. In this article, the authors address the evaluation and treatment of osteoporosis in women who have a history of early-stage breast carcinoma.

Electrohydraulic high-energy shock-wave treatment for chronic plantar fasciitis

BACKGROUND

Plantar fasciitis is a common foot disorder that may be resistant to nonoperative treatment. This study evaluated the use of electrohydraulic high-energy shock waves in patients who failed to respond to a minimum of six months of antecedent nonoperative treatment.

METHODS

A randomized, placebo-controlled, multiply blinded, crossover study was conducted. Phase 1 consisted of twenty patients who were nonrandomized to treatment with extracorporeal shock waves to assess the phase-2 study protocol. In phase 2, 293 patients were randomized and an additional seventy-one patients were nonrandomized. Following ankle-block anesthesia, each patient received 100 graded shocks starting at 0.12 to 0.22 mJ/mm(2), followed by 1400 shocks at 0.22 mJ/mm(2) with use of a high-energy electrohydraulic shock-wave device. Patients in the placebo group received minimal subcutaneous anesthetic injections and nontransmitted shock waves by the same protocol. Three months later, patients were given the opportunity to continue without further treatment or have an additional treatment. This allowed a patient in the active treatment arm to receive a second treatment and a patient who received the placebo to cross over to the active treatment arm. Patients were followed at least one year after the final treatment.

RESULTS

Treatment was successful in seventeen of the twenty phase-1 patients at three months. This improved to nineteen (95%) of twenty patients at one year and was maintained at five years. In phase 2, three months after treatment, sixty-seven (47%) of the 144 actively treated patients had a completely successful result compared with forty-two (30%) of the 141 placebo-treated patients (p = 0.008). At one year, sixty-five of the sixty-seven actively treated, randomized patients maintained a successful result. Thirty-six (71%) of the remaining fifty-one nonrandomized patients had a successful result at three months. For all 289 patients who had one or more actual treatments, 222 (76.8%) had a good or excellent result. No patient was made worse by the procedure.

CONCLUSIONS

The application of electrohydraulic high-energy shock waves to the heel is a safe and effective noninvasive method to treat chronic plantar fasciitis, lasting up to and beyond one year.

Nitric oxide mediates ultrasound-induced hypoxia-inducible factor-1alpha activation and vascular endothelial growth factor-A expression in human osteoblasts

Vascular endothelial growth factor (VEGF) is an important regulator for angiogenesis and endochondral bone formation. Although low-intensity pulsed ultrasound (US) has been recently used for accelerating fracture healing, the effect of US stimulation on angiogenic factor production by osteoblasts remains undetermined. Here, we found that US elevation of VEGF-A expression in human osteoblasts to be mediated by nitric oxide (NO) and hypoxia-inducible factor-1alpha (HIF-1alpha). Human osteoblasts were treated with or without US stimulation (200 micros pulse, 1 kHz at 30 mW/cm2) for 20 min. Cells were subjected to assessment of VEGF-A expression, NO production, nitric oxide synthase (NOS) catalytic activities, and HIF-1alpha transactivation. Results showed that US significantly increased VEGF-A mRNA and protein levels in 6 h. US augmentation of VEGF level was transcriptionally mediated. Early inhibition of NO production, but not calcium or prostaglandin E2, significantly reduced US-enhanced VEGF-A levels. Osteoblasts responded to US treatment by increasing NO production, NOS catalytic activities, iNOS immunoexpression, nuclear HIF-1alpha activation, and binding to the VEGF-A promoter. Inhibition of NOS activity by N-nitro-L-arginine methyl ester (L-NAME) or blockade of guanylate cyclase activity by ODQ reduced US-augmented HIF-1alpha transactivation and VEGF-A levels. Conditioned medium harvested from US-treated osteoblasts promoted tube formation of human umbilical vein endothelial cells (HUVEC). Monoclonal VEGF-A antibody neutralization or L-NAME pretreatment reduced the promoting effect of conditioned medium on angiogenesis of HUVEC. Together, these findings show that NO plays an important role in mediating extracellular stimuli released by US and triggering intracellular response of osteoblasts to produce angiogenic factor after US treatment.