Low-intensity pulsed ultrasound (LIPUS) in fresh clavicle fractures: a multi-centre double blind randomised controlled trial

Study on the Effects of Low-Intensity Pulsed Ultrasound and Iron Ions for Proliferation and Differentiation of Osteoblasts

OBJECTIVE

This study involved the proliferation and differentiation of osteoblasts treated with low-intensity pulsed ultrasound (LIPUS) and iron (Fe3+) ions, respectively. The biological effects of LIPUS and Fe3+ ions on the proliferation and differentiation of osteoblasts were also evaluated.

METHODS

MC3T3-E1 cells were seeded in six-well plates with the medium, which contained different concentrations of Fe3+ (0, 100, 200, 300, 400, 500, 600 and 700 μg L-1, respectively). LIPUS treatment was directed at the bottom of the plate for 20 min at an intensity of 80 mW cm-2 every day.

RESULTS

Viability results showed that a dose of 400 μg L-1 Fe3+ ions had the best effect at promoting osteogenic proliferation in cell culture. The results of alkaline phosphatase staining and mineralization indicated that the differentiation of osteoblasts was promoted by LIPUS and Fe3+ ions. Fluorescence staining results showed that the number of cell nuclei in the LIPUS, Fe3+ and LIPUS-Fe groups increased by 37.20%, 55.81% and 89.76%, respectively. Migration data indicated that migration and proliferation rates were increased by LIPUS and Fe3+, and the results of protein expression indicated that LIPUS and Fe3+ may increase the expression of Wnt, β-catenin, and Runx2, hence promoting normal bone regeneration and development.

CONCLUSION

The combination of LIPUS (1.5 MHz, 80 mW cm-2) and Fe3+ accelerates the proliferation and differentiation of osteoblasts significantly compared with single-factor treatment (stimulated by LIPUS and Fe3+ ions, respectively). This study could establish a foundation for LIPUS-responsive biomaterials in the repair and regeneration of bone tissues.

Latest Progress of LIPUS in Fracture Healing: A Mini-Review

The use of low-intensity pulsed ultrasound (LIPUS) for promoting fracture healing has been Food and Drug Administration (FDA)-approved since 1994 due to largely its non-thermal effects of sound flow sound radiation force and so on. Numerous clinical and animal studies have shown that LIPUS can accelerate the healing of fresh fractures, nonunions, and delayed unions in pulse mode regardless of LIPUS devices or circumstantial factors. Rare clinical studies show limitations of LIPUS for treating fractures with intramedullary nail fixation or low patient compliance. The biological effect is achieved by regulating various cellular behaviors involving mesenchymal stem/stromal cells (MSCs), osteoblasts, chondrocytes, and osteoclasts and with dose dependency on LIPUS intensity and time. Specifically, LIPUS promotes the osteogenic differentiation of MSCs through the ROCK-Cot/Tpl2-MEK-ERK signaling. Osteoblasts, in turn, respond to the mechanical signal of LIPUS through integrin, angiotensin type 1 (AT1), and PIEZO1 mechano-receptors, leading to the production of inflammatory factors such as COX-2, MCP-1, and MIP-1β fracture repair. LIPUS also induces CCN2 expression in chondrocytes thereby coordinating bone regeneration. Finally, LIPUS suppresses osteoclast differentiation and gene expression by interfering with the ERK/c-Fos/NFATc1 cascade. This mini-review revisits the known effects and mechanisms of LIPUS on bone fracture healing and strengthens the need for further investigation into the underlying mechanisms.

Study on Synergistic Effects of Nanohydroxyapatite/High-Viscosity Carboxymethyl Cellulose Scaffolds Stimulated by LIPUS for Bone Defect Repair of Rats

Despite the self-healing capacity of bone, the regeneration of critical-size bone defects remains a major clinical challenge. In this study, nanohydroxyapatite (nHAP)/high-viscosity carboxymethyl cellulose (hvCMC, 6500 mPa·s) scaffolds and low-intensity pulsed ultrasound (HA-LIPUS) were employed to repair bone defects. First, hvCMC was prepared from ramie fiber, and the degree of substitution (DS), purity, and content of NaCl of hvCMC samples were 0.91, 99.93, and 0.017%, respectively. Besides, toxic metal contents were below the permissible limits for pharmaceutically used materials. Our results demonstrated that the hvCMC is suitable for pharmaceutical use. Second, nHAP and hvCMC were employed to prepare scaffolds by freeze-drying. The results indicated that the scaffolds were porous, and the porosity was 35.63 ± 3.52%. Subsequently, the rats were divided into four groups (n = 8) randomly: normal control (NC), bone defect (BD), bone defect treated with nHAP/hvCMC scaffolds (HA), and bone defect treated with nHAP/hvCMC scaffolds and stimulated by LIPUS (HA-LIPUS). After drilling surgery, nHAP/hvCMC scaffolds were implanted in the defect region of HA and HA-LIPUS rats. Meanwhile, HA-LIPUS rats were treated by LIPUS (1.5 MHz, 80 mW cm-2) irradiation for 2 weeks. Compared with BD rats, the maximum load and bone mineral density of HA-LIPUS rats were increased by 20.85 and 51.97%, respectively. The gene and protein results indicated that nHAP/hvCMC scaffolds and LIPUS promoted the bone defect repair and regeneration of rats significantly by activating Wnt/β-catenin and inhibiting OPG/RANKL signaling pathways. Overall, compared with BD rats, nHAP/hvCMC scaffolds and LIPUS promoted bone defect repair significantly. Furthermore, the research results also indicated that there are synergistic effects for bone defect repair between the nHAP/hvCMC scaffolds and LIPUS.

American Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary on the Treatment of Clavicle Fractures

Treatment of Clavicle Fractures Evidence-Based Clinical Practice Guideline is based on a systematic review of published studies examining the diagnosis and treatment of clavicle fractures. This guideline contains four recommendations and 10 options to assist orthopaedic surgeons and any other qualified healthcare professionals with determining the treatment of isolated clavicle fractures based on the best current available evidence. It is also intended to serve as an information resource for healthcare professionals and developers of practice guidelines and recommendations. In addition to providing pragmatic practice recommendations, this guideline also highlights gaps in the literature and informs areas for future research and quality measure development. This guideline has been endorsed by the Orthopaedic Trauma Association, the American Shoulder and Elbow Surgeons, and the American Society of Shoulder and Elbow Therapists.

The fifty most-cited articles regarding midshaft clavicle fractures

Introduction

The clavicle is the most frequently fractured bone in the human body, and up to 80% of clavicle fractures occur in the middle third diaphyseal region of the clavicle (midshaft). We conducted a bibliometric analysis to identify and evaluate the 50 most-cited publications pertaining to midshaft clavicle fractures (MCF).

Materials and methods

Two independent reviewers conducted separate queries on Web of Science in December 2021 for "midshaft clavicle fractures". The publications yielded were organized from highest to lowest number of citations. We included articles, review articles, and editorial materials and excluded other document types. Both reviewers independently reviewed all abstracts until 50 studies pertaining to MCF were included.

Theory

We hypothesized that most articles would be published between 2000 and 2019, pertain to outcomes, and those with a greater (lower numeric) level of evidence would correlate with number of citations.

Results

The most prolific decade was from 2010 to 2019, with 50% (25/50) of articles published. Average citation density was 6.3 ± 5.5 (range, 1.3-33.1), defined as the average number of citations per year since publication. The median level of evidence (LOE) was 3.5 (IQR: 3). One-way ANOVA tests were used to compare the effects of LOE on total citations and citation density. There were statistically significant differences in total citations (F value = 12.07, p = 0.001) and citation density (F value = 21.14, p < 0.001) between LOE groups. The median number of total citations, grouped by LOE of 1 through 5, were as follows: 110, 66, 66, 51, 52.

Conclusions

This review provides an overview of the 50 most cited papers regarding MCF. This should be used as a reference for physicians and other providers who treat patients with MCF for treatment guidance and for those in teaching roles as a student and resident/fellow educational resource.

Ultrasound and shockwave therapy for acute fractures in adults

BACKGROUND

The morbidity and socioeconomic costs of fractures are considerable. The length of time to healing is an important factor in determining a person's recovery after a fracture. Ultrasound may have a therapeutic role in reducing the time to union after fracture by stimulating osteoblasts and other bone-forming proteins. This is an update of a review previously published in February 2014.   OBJECTIVES: To assess the effects of low-intensity ultrasound (LIPUS), high-intensity focused ultrasound (HIFUS) and extracorporeal shockwave therapies (ECSW) as part of the treatment of acute fractures in adults.  SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase (1980 to March 2022), Orthopaedic Proceedings, trial registers and reference lists of articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs including participants over 18 years of age with acute fractures (complete or stress fractures) treated with either LIPUS, HIFUS or ECSW versus a control or placebo-control.

DATA COLLECTION AND ANALYSIS

We used standard methodology expected by Cochrane. We collected data for the following critical outcomes: participant-reported quality of life, quantitative functional improvement, time to return to normal activities, time to fracture union, pain, delayed or non-union of fracture. We also collected data for treatment-related adverse events. We collected data in the short term (up to three months after surgery) and in the medium term (later than three months after surgery).   MAIN RESULTS: We included 21 studies, involving 1543 fractures in 1517 participants; two studies were quasi-RCTs. Twenty studies tested LIPUS and one trial tested ECSW; no studies tested HIFUS. Four studies did not report any of the critical outcomes. All studies had unclear or high risk of bias in at least one domain. The certainty of the evidence was downgraded for imprecision, risk of bias and inconsistency. LIPUS versus control (20 studies, 1459 participants) We found very low-certainty evidence for the effect of LIPUS on Health-related quality of life (HRQoL) measured by SF-36 at up to one year after surgery for lower limb fractures (mean difference (MD) 0.06, 95% confidence interval (CI) -3.85 to 3.97, favours LIPUS; 3 studies, 393 participants). This result was compatible with a clinically important difference of 3 units with both LIPUS or control. There may be little to no difference in time to return to work after people had complete fractures of the upper or lower limbs (MD 1.96 days, 95% CI -2.13 to 6.04, favours control; 2 studies, 370 participants; low-certainty evidence).  There is probably little or no difference in delayed union or non-union up to 12 months after surgery (RR 1.25, 95% CI 0.50 to 3.09, favours control; 7 studies, 746 participants; moderate-certainty evidence). Although data for delayed and non-union included both upper and lower limbs, we noted that there were no incidences of delayed or non-union in upper limb fractures. We did not pool data for time to fracture union (11 studies, 887 participants; very low-certainty evidence) because of substantial statistical heterogeneity which we could not explain. In upper limb fractures, MDs ranged from 0.32 to 40 fewer days to fracture union with LIPUS. In lower limb fractures, MDs ranged from 88 fewer days to 30 more days to fracture union. We also did not pool data for pain experienced at one month after surgery in people with upper limb fractures (2 studies, 148 participants; very low-certainty evidence) because of substantial unexplained statistical heterogeneity. Using a 10-point visual analogue scale, one study reported less pain with LIPUS (MD -1.7, 95% CI -3.03 to -0.37; 47 participants), and the effect was less precise in the other study (MD -0.4, 95% CI -0.61 to 0.53; 101 participants). We found little or no difference in skin irritation (a possible treatment-related adverse event) between groups but judged the certainty of the evidence from this small study to be very low (RR 0.94, 95% CI 0.06 to 14.65; 1 study, 101 participants). No studies reported data for functional recovery. Data for treatment adherence were inconsistently reported across studies, but was generally described to be good. Data for costs were reported for one study, with higher direct costs, as well as combined direct and indirect costs, for LIPUS use. ECSW versus control (1 study, 56 participants) We are uncertain whether ECSW reduces pain at 12 months after surgery in fractures of the lower limb (MD -0.62, 95% CI -0.97 to -0.27, favours ECSW); the difference between pain scores was unlikely to be clinically important, and the certainty of the evidence was very low. We are also uncertain of the effect of ECSW on delayed or non-union at 12 months because the certainty of this evidence is very low (RR 0.56, 95% CI 0.15 to 2.01; 1 study, 57 participants). There were no treatment-related adverse events. This study reported no data for HRQoL, functional recovery, time to return to normal activities, or time to fracture union. In addition, no data were available for adherence or cost.

AUTHORS' CONCLUSIONS

We were uncertain of the effectiveness of ultrasound and shock wave therapy for acute fractures in terms of patient-reported outcome measures (PROMS), for which few studies reported data. It is probable that LIPUS makes little or no difference to delayed union or non-union. Future trials should be double-blind, randomised, placebo-controlled trials recording validated PROMs and following up all trial participants. Whilst time to union is difficult to measure, the proportion of participants achieving clinical and radiographic union at each follow-up point should be ascertained, alongside adherence with the study protocol and cost of treatment in order to better inform clinical practice.

Traumatic brain injuries are ignored or discriminated in prospective clinical trials on shoulder fractures: a systematic review

PURPOSE

Current literature suggests a significant epidemiological association between traumatic brain injury (TBI) and proximal upper limb fractures in addition to major clinical consequences. A systematic review was conducted to assess how TBI is taken into consideration in interventional studies on shoulder fractures.

METHODS

The following data sources were used: MEDLINE, EMBASE, EBM Reviews, CINAHL, and OpenGrey databases. Study selection included interventional randomized clinical trials and prospective cohort studies on shoulder fractures published in English or French between 2008 and 2020. Studies on pathologic fractures, chronic fracture complications, nonhuman subjects, and biomechanics were excluded. Articles were reviewed by two independent authors according to the PRISMA guidelines. Baseline characteristics, exclusion criteria, and input relevant to TBI were recorded. Methodological quality was assessed with the Cochrane risk of bias tool for randomized clinical trials and the Newcastle-Ottawa Scale for cohort studies.

RESULTS

One-hundred-thirteen studies met the inclusion criteria. None discussed the possible impact of TBI on their results. Only three (2.7%) studies considered TBI relevant and included these patients in their cohort. Furthermore, 43/113 (38.1%) excluded patients with injuries or mechanisms strongly related to traumatic brain injuries: head injuries (4); moderate and/or severe TBI (7); high energy traumas (3); Polytrauma subjects (33).

CONCLUSION

TBI are ignored or discriminated in prospective clinical trials on shoulder fractures. The exclusion of these cases impacts generalizability as their prevalence is significant. Considering the major impact of TBI on important outcomes, its presence should always be assessed to ensure high quality evidence.

LEVEL OF EVIDENCE

Systematic Review, Therapeutic Level II.

Instructional review of key factors to achieve successful outcomes when using low-intensity pulsed ultrasound in fracture repair

Low-intensity pulsed ultrasound (LIPUS) treatment of fractures has been available to the orthopaedic community for nearly three decades; however, it is still considered an experimental treatment by some clinicians, even though there is a wealth of clinical data. Based on the evaluation of clinical trial data, we have established key criteria which can lead to LIPUS success and avoid failure. These are fracture gap size and stability, accurate transducer placement and minimum treatment number. However, from a clinician's view, the correct attitude to treatment must be observed, and this has also been discussed. It is hoped, armed with this new evaluation of the clinical data, that clinicians can treat patients with LIPUS more effectively, resulting in fewer failures of treatment.

Low-intensity pulsed ultrasound does not promote bone healing and functional recovery after open wedge high tibial osteotomy

Aims

To evaluate whether low-intensity pulsed ultrasound (LIPUS) accelerates bone healing at osteotomy sites and promotes functional recovery after open-wedge high tibial osteotomy (OWHTO).

Methods

Overall, 90 patients who underwent OWHTO without bone grafting were enrolled in this nonrandomized retrospective study, and 45 patients treated with LIPUS were compared with 45 patients without LIPUS treatment in terms of bone healing and functional recovery postoperatively. Clinical evaluations, including the pain visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score, were performed preoperatively as well as six weeks and three, six, and 12 months postoperatively. The progression rate of gap filling was evaluated using anteroposterior radiographs at six weeks and three, six, and 12 months postoperatively.

Results

The pain VAS and JOA scores significantly improved after OWHTO in both groups. Although the LIPUS group had better pain scores at six weeks and three months postoperatively, there were no significant differences in JOA score between the groups. The lateral hinge united at six weeks postoperatively in 34 (75.6%) knees in the control group and in 33 (73.3%) knees in the LIPUS group. The progression rates of gap filling in the LIPUS group were 8.0%, 15.0%, 27.2%, and 46.0% at six weeks and three, six, and 12 months postoperatively, respectively, whereas in the control group at the same time points they were 7.7%, 15.2%, 26.3%, and 44.0%, respectively. There were no significant differences in the progression rate of gap filling between the groups.

Conclusion

The present study demonstrated that LIPUS did not promote bone healing and functional recovery after OWHTO with a locking plate. The routine use of LIPUS after OWHTO was not recommended from the results of our study. Cite this article: Bone Jt Open 2022;3(11):885–893.

Low-Intensity Pulsed Ultrasound Stimulation for Bone Fractures Healing: A Review

Low-intensity pulsed ultrasound (LIPUS) is a developing technology, which has been proven to improve fracture healing process with minimal thermal effects. This noninvasive treatment accelerates bone formation through various molecular, biological, and biomechanical interactions with tissues and cells. Although LIPUS treatment has shown beneficial effects on different bone fracture locations, only very few studies have examined its effects on deeper bones. This study provides an overview on therapeutic ultrasound for fractured bones, possible mechanisms of action, clinical evidences, current limitations, and its future prospects.

Low-intensity pulsed ultrasound (LIPUS) for stimulation of bone healing - A narrative review

The use of low intensity pulsed ultrasound (LIPUS) to accelerate the fracture repair process in humans was first reported by Xavier & Duarte in 1983 [1]. This success led to clinical trials and the 1994 approval of LIPUS in the United States for the accelerated healing of certain fresh fractures. LIPUS was approved in the US for the treatment of established non-unions in 2000, and is also approved around the world. In this article, we present relevant literature on the effect of LIPUS on bone healing in patients with acute fractures and non-unions and provide a molecular explanation for the effects of LIPUS on bone healing. Data on LIPUS accelerated fracture repair is controversial with many controlled studies showing a positive effect. However, the largest trial in acute tibial fractures stabilized with an intramedullary nail failed to show significant differences in accelerated healing and in functional outcomes. Uncontrolled data from prospective case series suggest a positive effect of LIPUS in non united fractures with healing rates of around 85%. Evaluation of results from studies, both positive and negative, has enabled an understanding that the patient population with potentially the greatest benefit from receiving LIPUS are those at-risk for fracture healing, e.g. diabetic & elderly patients. The elucidation of a pathway to activate the Rac-1 pathway by LIPUS might explain this beneficial effect. Overall, there is a strong need for further clinical trials, particularly for acute fractures at risk of progressing to non-union and in established non-unions including a comparison to the current standard of care.

Electroactive barium titanate coated titanium scaffold improves osteogenesis and osseointegration with low-intensity pulsed ultrasound for large segmental bone defects

For large segmental bone defects, porous titanium scaffolds have some advantages, however, they lack electrical activity which hinders their further use. In this study, a barium titanate (BaTiO3) piezoelectric ceramic was used to modify the surface of a porous Ti6Al4V scaffold (pTi), which was characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and roughness and water contact angle analyses. Low intensity pulsed ultrasound (LIPUS) was applied in vitro and in vivo study. The activity of bone marrow mesenchymal stem cells, including adhesion, proliferation, and gene expression, was significantly superior in the BaTiO3/pTi, pTi + LIPUS, and BaTiO3/pTi + LIPUS groups than in the pTi group. The activity was also higher in the BaTiO3/pTi + LIPUS group than in the BaTiO3/pTi and pTi + LIPUS groups. Additionally, micro-computed tomography, the mineral apposition rate, histomorphology, and the peak pull-out load showed that these scaffold conditions significantly enhanced osteogenesis and osseointegration 6 and 12 weeks after implantation in large segmental bone defects in the radius of rabbits compared with those resulting from the pTi condition. Consequently, the improved osteogenesis and osseointegration make the BaTiO3/pTi + LIPUS a promising method to promote bone regeneration in large segmental bone defects for clinical application.

Clinical and patient-reported outcomes following Low Intensity Pulsed Ultrasound (LIPUS, Exogen) for established post-traumatic and post-surgical nonunion in the foot and ankle

BACKGROUND

Biophysical methods including Low Intensity Pulsed Ultrasound (LIPUS) are emerging as potential alternatives to revision surgery for treating established nonunions. We aim to prospectively review the clinical and patient-reported outcomes of patients treated with LIPUS following post-traumatic and post-surgical nonunions in the foot and ankle.

METHODS

Forty-seven consecutive patients underwent Exogen treatment. Patient-reported outcome scores included MOXFQ, EQ-5D and VAS. Patients were divided in to 3 groups: fractures (A), hindfoot procedures (B) and midfoot/forefoot procedures (C).

RESULTS

Thirty-seven patients (78.7%) clinically united, 4 patients (8.5%) noticed no significant improvement but did not want further intervention and 6 patients (12.8%) underwent revision surgery. The mean duration of Exogen treatment was 6 months. Union rates of 93%, 67% and 78% were noted in the three groups. Significant improvement in functional outcomes and potential cost savings were observed.

CONCLUSIONS

Exogen for established nonunion in the foot and ankle is a safe, valuable and economically viable clinical option as an alternative to revision surgery. We observed better results in the fracture and midfoot/forefoot groups and relatively poorer results in the hindfoot fusion group.

Mechanotransduction in osteogenesis

Bone is one of the most highly adaptive tissues in the body, possessing the capability to alter its morphology and function in response to stimuli in its surrounding environment. The ability of bone to sense and convert external mechanical stimuli into a biochemical response, which ultimately alters the phenotype and function of the cell, is described as mechanotransduction. This review aims to describe the fundamental physiology and biomechanisms that occur to induce osteogenic adaptation of a cell following application of a physical stimulus. Considerable developments have been made in recent years in our understanding of how cells orchestrate this complex interplay of processes, and have become the focus of research in osteogenesis. We will discuss current areas of preclinical and clinical research exploring the harnessing of mechanotransductive properties of cells and applying them therapeutically, both in the context of fracture healing and de novo bone formation in situations such as nonunion.

Cite this article: Bone Joint Res 2019;9(1):1–14.

The socioeconomic impact of orthopaedic trauma: A systematic review and meta-analysis

The overall objective of this study was to determine the patient-level socioeconomic impact resulting from orthopaedic trauma in the available literature. The MEDLINE, Embase, and Scopus databases were searched in December 2019. Studies were eligible for inclusion if more than 75% of the study population sustained an appendicular fracture due to an acute trauma, the mean age was 18 through 65 years, and the study included a socioeconomic outcome, defined as a measure of income, employment status, or educational status. Two independent reviewers performed data extraction and quality assessment. Pooled estimates of the socioeconomic outcome measures were calculated using random-effects models with inverse variance weighting. Two-hundred-five studies met the eligibility criteria. These studies utilized five different socioeconomic outcomes, including return to work (n = 119), absenteeism days from work (n = 104), productivity loss (n = 11), income loss (n = 11), and new unemployment (n = 10). Pooled estimates for return to work remained relatively consistent across the 6-, 12-, and 24-month timepoint estimates of 58.7%, 67.7%, and 60.9%, respectively. The pooled estimate for mean days absent from work was 102.3 days (95% CI: 94.8-109.8). Thirteen-percent had lost employment at one-year post-injury (95% CI: 4.8-30.7). Tremendous heterogeneity (I2>89%) was observed for all pooled socioeconomic outcomes. These results suggest that orthopaedic injury can have a substantial impact on the patient's socioeconomic well-being, which may negatively affect a person's psychological wellbeing and happiness. However, socioeconomic recovery following injury can be very nuanced, and using only a single socioeconomic outcome yields inherent bias. Informative and accurate socioeconomic outcome assessment requires a multifaceted approach and further standardization.

Effect of Low-Intensity Pulsed Ultrasound Stimulation, Extracorporeal Shockwaves and Radial Pressure Waves on Akt, BMP-2, ERK-2, FAK and TGF-β1 During Bone Healing in Rat Tibial Defects

An experimental study was conducted to determine whether low-intensity pulsed ultrasound stimulation (LIPUS), extracorporeal shockwave treatment (ESWT) and radial pressure wave treatment (RPWT) modulate Akt, bone morphogenetic protein-2 (BMP-2), extracellular signal-regulated kinase-2 (ERK-2), focal adhesion kinase (FAK) and transforming growth factor-β1 (TGF-β1) during bone healing in rat tibial defects. Rat tibial defects were exposed to 500 shots of ESWT delivered at 0.12 mJ/mm², 500 impulses of RPWT operated at 2.0 bar or to daily 20-min 30 mW/cm² LIPUS. Following 1, 3 and 6 wk, bones were harvested to determine the expression and activity of Akt, BMP-2, ERK-2, FAK and TGF-β1. Animals exposed to ultrasound were followed up to 3 wk. Protein expression and activity were unchanged following LIPUS treatment. ESWT increased Akt activity 2.11-fold (p = 0.043) and TGF-β1 expression 9.11-fold (p = 0.016) at 1 wk and increased FAK activity 2.16-fold (p = 0.047) at 3 wk. RPWT increased FAK activity 2.6-fold (p = 0.028) at 3 wk and decreased Akt expression 0.52-fold (p = 0.05) at 6 wk. In conclusion, the protocols employed for ESWT and RPWT modulated distinct signaling pathways during fracture healing, while LIPUS standard protocol did not change the usual signaling pathways of the proteins investigated. Future studies are required to monitor osteogenesis so that the biologic meaning of our results can be clarified.

Regulation of exosomes secretion by low-intensity pulsed ultrasound in lung cancer cells

Low-intensity pulsed ultrasound (LIPUS) is a noninvasive therapeutic method which gradually being used in clinic including cancers. Exosomes mediate intercellular communication functions in disease development and the potential clinical applications in diagnosis and therapy. However, few studies have discussed the relationship between LIPUS and exosomes. Herein, we show that low intensity (0.6-2.1 W/cm² or 0.6-3.4 W/cm²) LIPUS promoted exosomes secretion whereas higher intensity (3.4-5.0 W/cm² or 5.0 W/cm²) LIPUS inhibited exosomes secretion, and this phenomenon is associated with autophagy. Pretreatment with 3-MA or down-regulation of LC3 potentiated low intensity LIPUS's promotion of exosomes secretion and conferred resistance to higher intensity LIPUS's effects on exosomes secretion. Furthermore, pretreatment with PP242 attenuated LIPUS-influenced exosomes secretion while expression of constitutively active Akt (Ad-myr-Akt) elevated LIPUS-influenced exosomes secretion, implying mTOR-dependent mechanism involved. The findings indicate that LIPUS influences exosomes secretion by targeting mTOR-mediated LC3 signaling in SPC-A1 and SPC-A1-BM cells. Our data provided initial evidence to connect LIPUS and secretion of exosomes, and highlight that LIPUS may be exploited in exosome-related diseases.

Enhancement of Bone-Healing by Low-Intensity Pulsed Ultrasound: A Systematic Review

BACKGROUND

Low-intensity pulsed ultrasound (LIPUS) is frequently used to enhance or to accelerate fracture-healing, but its clinical role and effectiveness as a treatment modality remain uncertain. We performed a systematic review and meta-analysis of randomized controlled trials to determine the efficiency of LIPUS on bone-healing and/or fracture union, as well as on functional recovery.

METHODS

The databases of PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, and Embase were searched for trials concerning LIPUS stimulation and bone-healing or fracture repair, in any language, published from the inception of the database to January 2, 2015. Eligible studies were randomized controlled trials that enrolled patients with any type of fracture, delayed union, or nonunion and randomly assigned them to LIPUS treatment or a control group. Two reviewers independently agreed on eligibility, assessed methodological quality, and extracted outcome data. All relevant outcomes were pooled, and a meta-analysis was performed.

RESULTS

Twenty-four unique randomized trials were selected for analysis after the search of all databases and the inclusion of one trial by the senior author. Time to radiographic fracture union was the most common primary outcome measure evaluated. After pooling the data concerning time to radiographic healing in the combined patient population (n = 429), LIPUS treatment resulted in a mean reduction in healing time of 39.8 days (95% confidence interval, 17.7 to 62.0 days; I = 94%). The most reduction in time to radiographic union by LIPUS treatment was seen in fractures with a long natural healing tendency. Three trials evaluating the time to return to work or active duty, as a surrogate for functional recovery, were unable to demonstrate a beneficial effect of LIPUS (n = 179). Evidence from two high-quality trials implied that LIPUS enhances fracture-healing through increased bone formation in cases of delayed and/or impaired bone-healing. The prevention of delayed union or nonunion by LIPUS treatment could not be demonstrated.

CONCLUSIONS

LIPUS treatment effectively reduces the time to radiographic fracture union, but this does not directly result in a beneficial effect of accelerated functional recovery or the prevention of delayed union or nonunion. The increase in bone formation as a result of LIPUS treatment may provide a valuable tool in fracture repair, but it does not always lead to healing. Future studies should focus on reporting of a combination of subjective signs of clinical healing, functional recovery, and radiographic union to determine the effectiveness of LIPUS treatment in clinical fracture-healing.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Comparison of effects of LLLT and LIPUS on fracture healing in animal models and patients: A systematic review

The aim of this paper is to study the in vivo potency of low-level laser therapy (LLLT) and low intensity pulsed ultrasound (LIPUS) alone, accompanied by bone grafts, or accompanied by other factors on fracture healing in animal models and patients. In this paper, we aim to systematically review the published scientific literature regarding the use of LLLT and LIPUS to accelerate fracture healing in animal models and patients. We searched the PubMed database for the terms LLLT or LIPUS and/or bone, and fracture. Our analysis also suggests that both LIPUS and LLLT may be beneficial to fracture healing in patients, and that LIPUS is more effective. These finding are of considerable importance in those treatments with a LIPUS, as a laser device may reduce healing time. The most clinically relevant impact of the LIPUS treatment could be a significant reduction in the proportion of patients who go on to develop a nonunion. If it is confirmed that the therapeutic influence is true and reliable, patients will obtain benefits from LIPUS and LLLT. Further clinical trials of high methodological quality are needed in order to determine the optimal role of LIPUS and LLLT in fracture healing in patients.

Vocational rehabilitation for enhancing return-to-work in workers with traumatic upper limb injuries

BACKGROUND

Traumatic upper limb injury is a leading cause of work-related disability. After return-to-work (RTW), many survivors of injuries are able to regain a quality of life (QoL) comparable with the normal population. Since RTW plays an important role in economic productivity and regaining health-related QoL, enhancing RTW in workers with traumatic limb injuries is the primary goal of rehabilitation. Vocational rehabilitation has been commonly employed in the field of occupational safety and health to increase the number of injured people returning to the labour market, prevent illness, increase well-being, and reduce disability.

OBJECTIVES

To assess the effects of vocational rehabilitation programmes for enhancing RTW in workers with traumatic upper limb injuries.

SEARCH METHODS

This is an update of a Cochrane review previously published in 2013. We updated our searches of the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 9), MEDLINE (to 30 August 2017), EMBASE (to 3 September 2017), CINAHL (to 6 September 2017), and PsycINFO (to 6 September 2017), and we handsearched the references lists of relevant review articles.

SELECTION CRITERIA

We aimed to include all randomised controlled trials (RCTs) comparing vocational rehabilitation with an alternative (control) intervention such as standard rehabilitation, a limited form of the vocational rehabilitation intervention (such as advice on RTW, referral information, or liaison with employer), or waiting-list controls.

DATA COLLECTION AND ANALYSIS

Two authors independently inspected abstracts, and we obtained full papers when necessary. When the two authors disagreed about the inclusion of a study, we resolved disagreements by discussion. A third author arbitrated when necessary.

MAIN RESULTS

Our updated search identified 466 citations. Based on assessments of their titles and abstracts, we decided to evaluate the full texts of five records; however, none met our inclusion criteria.

AUTHORS' CONCLUSIONS

There is currently no high-quality evidence to support or refute the efficacy of vocational rehabilitation for enhancing RTW in workers with traumatic upper limb injuries. Since injured people in occupational settings frequently receive vocational rehabilitation with the aim of decreasing work disability, enhancing RTW, increasing productivity, and containing the welfare cost, further high-quality RCTs assessing the efficacy of vocational rehabilitation for workers with traumatic upper limb injury are needed to fill this gap in knowledge.

The effects of low-intensity pulsed ultrasound on fresh fracture: A meta-analysis

BACKGROUND

Low-intensity pulsed ultrasonography (LIPUS) is a form of mechanical stimulation that is delivered via a special device to the fracture site for the acceleration of fracture healing. We conducted a meta-analysis to assess the effect of LIPUS for fresh fractures in adults.

METHODS

MEDLINE, EMBASE and the Cochrane Library searched between Jan 1980 and Nov 2016. Studies should be quasi-randomized and randomized controlled trials (RCTs) comparing treatment with LIPUS to placebo or no treatment in adults with fresh fractures, reporting outcomes such as function; time to union; delayed union or non-union. Summary standard mean difference (SMD) and the risk ratio (RR) with their 95% confidence interval (CI) calculated with a random effects model. I statistic was used to assess the heterogeneity. Risk of bias was assessed by the Cochrane risk-of-bias tool. The GRADE system was used to evaluate the evidence quality.

RESULTS

A total of 12 trials with 1099 patients were included. The pooled results showed that LIPUS significantly reduced the time to fracture union (SMD: 0.65, 95% CI: 1.13 to 0.17), improved the quality of life (SMD: 0.20, 95% CI: 0.03-0.37) without affecting the time to full weight bearing (SMD: 0.76, 95% CI: 1.92 to 0.4), the time to return to work (SMD: 0.06, 95% CI: 0.14 to 0.27), or the incidence rate of delayed union and nonunion (RR: 1.02, 95% CI: 0.60-1.74).

CONCLUSIONS

Moderate-to-high quality evidence shows that LIPUS treatment reduces the time to fracture union and improves the quality of life without affecting functional recovery and incident rate of delayed union and nonunion, suggesting that LIPUS treatment may be a good treatment modality for adults with fresh fractures. However, there are some methodological limitations in the eligible trials, further studies are needed to determine the clinical circumstances under which LIPUS is truly valid and to examine the optimal approach for the use of this adjunctive therapy.

Low-intensity pulsed ultrasound does not influence bone healing by distraction osteogenesis: a multicentre double-blind randomised control trial

AIMS

The aim of this double-blind prospective randomised controlled trial was to assess whether low intensity pulsed ultrasound (LIPUS) accelerated or enhanced the rate of bone healing in adult patients undergoing distraction osteogenesis.

PATIENTS AND METHODS

A total of 62 adult patients undergoing limb lengthening or bone transport by distraction osteogenesis were randomised to treatment with either an active (n = 32) or a placebo (n = 30) ultrasound device. A standardised corticotomy was performed in the proximal tibial metaphysis and a circular Ilizarov frame was used in all patients. The rate of distraction was also standardised. The primary outcome measure was the time to removal of the frame after adjusting for the length of distraction in days/cm for both the per protocol (PP) and the intention-to-treat (ITT) groups. The assessor was blinded to the form of treatment. A secondary outcome was to identify covariates affecting the time to removal of the frame.

RESULTS

There was no difference in the time to removal of the frame between the PP (difference in favour of the control group was 10.1 days/cm, 95% confidence interval (CI) -3.2 to 23.4, p = 0.054) or ITT (difference 5.0 days/cm, 95% CI -8.2 to 18.21, p = 0.226) groups. The smoking status was the only covariate which increased the time to removal of the frame (hazard ratio 0.47, 95% CI 0.22 to 0.97, p = 0.042).

CONCLUSION

LIPUS does not influence the rate of bone healing in patients who undergo distraction osteogenesis. Smoking may influence bone healing. Cite this article: Bone Joint J 2017;99-B:494-502.

Low intensity pulsed ultrasound for bone healing: systematic review of randomized controlled trials

Objective To determine the efficacy of low intensity pulsed ultrasound (LIPUS) for healing of fracture or osteotomy.Design Systematic review and meta-analysis.Data sources Medline, Embase, CINAHL, Cochrane Central Register of Controlled Trials, and trial registries up to November 2016.Study selection Randomized controlled trials of LIPUS compared with sham device or no device in patients with any kind of fracture or osteotomy.Review methods Two independent reviewers identified studies, extracted data, and assessed risk of bias. A parallel guideline committee (BMJ Rapid Recommendation) provided input on the design and interpretation of the systematic review, including selection of outcomes important to patients. The GRADE system was used to assess the quality of evidence.Results 26 randomized controlled trials with a median sample size of 30 (range 8-501) were included. The most trustworthy evidence came from four trials at low risk of bias that included patients with tibia or clavicle fractures. Compared with control, LIPUS did not reduce time to return to work (percentage difference: 2.7% later with LIPUS, 95% confidence interval 7.7% earlier to 14.3% later; moderate certainty) or the number of subsequent operations (risk ratio 0.80, 95% confidence interval 0.55 to 1.16; moderate certainty). For pain, days to weight bearing, and radiographic healing, effects varied substantially among studies. For all three outcomes, trials at low risk of bias failed to show a benefit with LIPUS, while trials at high risk of bias suggested a benefit (interaction P<0.001). When only trials at low risk of bias trials were considered, LIPUS did not reduce days to weight bearing (4.8% later, 4.0% earlier to 14.4% later; high certainty), pain at four to six weeks (mean difference on 0-100 visual analogue scale: 0.93 lower, 2.51 lower to 0.64 higher; high certainty), and days to radiographic healing (1.7% earlier, 11.2% earlier to 8.8% later; moderate certainty).Conclusions Based on moderate to high quality evidence from studies in patients with fresh fracture, LIPUS does not improve outcomes important to patients and probably has no effect on radiographic bone healing. The applicability to other types of fracture or osteotomy is open to debate.Systematic review registration PROSPERO CRD42016050965.

Conservative interventions for treating middle third clavicle fractures in adolescents and adults

BACKGROUND

Clavicle (collarbone) fractures account for around 4% of all fractures. Most (76%) clavicle fractures involve the middle-third section of the clavicle. Treatment of these fractures is usually non-surgical (conservative). Commonly used treatments are arm slings, strapping and figure-of-eight bandages.This is an update of a Cochrane review first published in 2009 and updated in 2014.

OBJECTIVES

To evaluate the effects (benefits and harms) of different methods for conservative (non-operative) treatment for acute (treated soon after injury) middle third clavicle fractures in adolescents and adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE (from 1966), Embase (from 1980), LILACS (from 1982), trial registers, orthopaedic proceedings and reference lists of articles. We applied no language or publication restrictions. The date of the last search was 5 January 2016.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials testing conservative interventions for treating adolescents and adults with acute middle third clavicle fractures. The primary outcomes were shoulder function or disability, pain and treatment failure.

DATA COLLECTION AND ANALYSIS

For this update, two review authors selected eligible trials, independently assessed risk of bias and cross-checked data extraction. We calculated risk ratios and 95% confidence intervals for dichotomous variables, and mean differences and 95% confidence intervals for continuous variables. There was very limited pooling of data.

MAIN RESULTS

We included four trials in this review with 416 participants, who were aged 14 years or above. One new trial was included in this update.Very low quality evidence was available from three trials (296 participants) that compared the figure-of-eight bandage with an arm sling for treating acute middle third clavicle fractures. The three trials were underpowered and compromised by poor methodology. Shoulder function was assessed in different ways in the three trials (data for 51, 61 and 152 participants); each trial provided very low quality evidence of similar shoulder function in the two groups. Pooled data from two trials (203 participants) showed no clinical difference between groups after two weeks in pain (visual analogue scale: 0 (no pain) to 10 (worst pain); mean difference (MD) 0.43, 95% confidence interval (CI) -0.35 to 1.21; I² = 74%; very low quality evidence). A third trial (61 participants) provided very low quality evidence based on a non-validated scoring system of more pain and discomfort during the course of treatment in the figure-of-eight group. Treatment failure, measured in terms of subsequent surgery, was not reported in two trials; the third trial (152 participants) reported one participant in the arm sling group had surgery for secondary plexus nerve palsy. There was very low quality evidence from one trial (148 participants) of little difference in time to clinical fracture healing (MD 0.2 weeks, 95% CI -0.11 to 0.51); data from four non-symptomatic non-unions in the figure-of-eight group were not included. The very low evidence quality data for individual adverse outcomes (poor cosmetic appearance; change in allocated treatment due to pain and discomfort, worsened fracture position on healing; shortening > 15 mm; non-symptomatic non-union and permanent pain) did not confirm a difference between the two groups. There was no clear between group difference in the time to return to school or work activities (MD -0.12 weeks, 95% CI -0.69 to 0.45; 176 participants; very low quality evidence).Moderate quality evidence was available from one trial (120 participants; reporting data for 101 participants), which evaluated therapeutic ultrasound. This trial was at low risk of bias but was underpowered and did not report on shoulder function or quality of life. The trial found no evidence of a difference between low-intensity pulsed ultrasound and placebo in pain, treatment failure (subsequent surgery: 6/52 versus 5/49; RR 1.13, 95% CI 0.37 to 3.47), the time to clinical fracture healing (MD -0.32 days, 95% CI -5.85 to 5.21), adverse events (one case of skin irritation was reported in each group) or time to resume previous activities.

AUTHORS' CONCLUSIONS

The current evidence available from randomised controlled trials is insufficient to determine which methods of conservative treatment are the most appropriate for acute middle third clavicle fractures in adolescents and adults. Further research is warranted.

Influence of Donor Age and Stimulation Intensity on Osteogenic Differentiation of Rat Mesenchymal Stromal Cells in Response to Focused Low-Intensity Pulsed Ultrasound

A focused low-intensity pulsed ultrasound (FLIPUS) was used to investigate the effects of stimulation period, acoustic intensity and donor age on the osteogenic differentiation potential of rat mesenchymal stromal cells (rMSCs). rMSCs from 3- and 12-mo-old female Sprague Drawly rats were isolated from bone marrow and stimulated 20 min/d with either 11.7 or 44.5 mW/cm² (spatial average temporal average intensity) for 7 or 14 d. Osteogenic differentiation markers, i.e., Runt-related transcription factor 2 (RUNX2), osteocalcin (OCN) and degree of matrix calcification were analyzed. On day 7 of stimulation, OCN gene expression was enhanced 1.9-fold in cells from young rats when stimulated with low intensity. The low intensity also led to a 40% decrease in RUNX2 expression on day 7 in aged cells, whereas high intensity enhanced expression of RUNX2 on day 14. FLIPUS treatment with low intensity resulted in a 15% increase in extracellular matrix mineralization in young but not old rMSCs. These differences suggest the necessity of a donor-age related optimization of stimulation parameters.

Design evolution enhances patient compliance for low-intensity pulsed ultrasound device usage

Poor patient compliance or nonadherence with prescribed treatments can have a significant unfavorable impact on medical costs and clinical outcomes. In the current study, voice-of-the-customer research was conducted to aid in the development of a next-generation low-intensity pulsed ultrasound (LIPUS) bone healing product. An opportunity to improve patient compliance reporting was identified, resulting in the incorporation into the next-generation device of a visual calendar that provides direct feedback to the patient, indicating days for which they successfully completed treatment. Further investigation was done on whether inclusion of the visual calendar improved patient adherence to the prescribed therapy (20 minutes of daily treatment) over a 6-month period. Thus, 12,984 data files were analyzed from patients prescribed either the earlier- or the next-generation LIPUS device. Over the 6-month period, overall patient compliance was 83.8% with the next-generation LIPUS device, compared with 74.2% for the previous version (p<0.0001). Incorporation of the calendar feature resulted in compliance never decreasing below 76% over the analysis period, whereas compliance with the earlier-generation product fell to 51%. A literature review on the LIPUS device shows a correlation between clinical effectiveness and compliance rates more than 70%. Incorporation of stakeholder feedback throughout the design and innovation process of a next-generation LIPUS device resulted in a measurable improvement in patient adherence, which may help to optimize clinical outcomes.

Comparison between various densities of pore titanium meshes and e-polytetrafluoroethylene (ePTFE) membrane regarding bone regeneration induced by low intensity pulsed ultrasound (LIPUS) in rabbit nasal bone

PURPOSE

The purpose of this study was to compare bone regenerative capability following use of polytetrafluoroethylene (ePTFE) membrane against that when various densities of pore titanium meshes are used with and without low intensity pulsed ultrasound (LIPUS).

MATERIALS AND METHODS

Adult male white rabbits were divided into 8 groups. In 4 groups, after incising along the nasal bone, four 3 × 8 mm bone defects were made in both sides and covered by an ePTFE membrane (group E: n = 15), a high density pore titanium mesh (group H: n = 15), a low density pore titanium mesh (group L: n = 15), and no mesh (control) (group C: n = 15). Furthermore, LIPUS was irradiated after surgery in 4 groups (groups EL, HL, LL and CL, in each n = 15). The rabbits were sacrificed at 1, 2 and 8 weeks postoperative, and formalin-fixed specimens were embedded in acrylic resin. The specimens were stained with hematoxylin and eosin. For immunohistochemical analysis, the specimens were treated with bone morphogenetic protein (BMP)-2 antibody.

RESULTS

Group H had significantly higher values than groups L, E, and C regarding bone area ratio and labeling index of BMP-2 positive cells (P < 0.05). Furthermore, Group HL also had significantly higher values than the other groups regarding bone area ratio and labeling index of BMP-2 positive cells at 1, 2 and 8 weeks postoperative (P < 0.05).

CONCLUSION

The results suggested that high density pore titanium mesh could induce new bone regeneration more than low density pore titanium mesh and ePTFE membrane. New bone formation may increase following LIPUS application.

Failed treatment of long bone nonunions with low intensity pulsed ultrasound

INTRODUCTION

The use of low intensity pulsed ultrasound (LIPUS) in the treatment of nonunions is still controversial. The present study is concerned with whether this procedure has a clinical use and which cofactors influence its therapeutic results.

METHODS

In this prospective, single institution, observational study, data from October 2010 to October 2013 from 61 nonunions in 60 patients treated with EXOGEN(®) LIPUS therapy were analysed. The average age was 45.4 ± 9.81 (18-63) years. Treatment was primarily done on long bones of the lower extremity (75.4 %). All 61 nonunions were examined after treatment, and the rate of healing as well as functional and subjective results were evaluated. Based on clinical and radiological findings, patients were divided into two groups: G1-successful treatment; and G2-unsuccessful treatment. Groups were compared to one another to identify possible factors influencing treatment.

RESULTS

Twenty (32.8 %) patients showed bone consolidation with an average time of healing of 5.3 (2-7) months. In patients without successful treatment, who underwent revision surgery instead, full weight bearing took on average 3.7 months longer, and they were able to return to work 6.8 months later. Most of the treated patients (70.5 %) reported no improvement in pain. In G2, 12 (29.3 %) patients suffered in their previous history from osteitis; in G1 there were only two patients (10 %) (p = 0.012). There were further significant differences in the age of the fracture, the type of osteosynthesis, the gap size, as well as the NUSS score.

CONCLUSION

Despite patients being chosen strictly according to EXOGEN(®) indications, only a small number of patients with nonunions who underwent LIPUS therapy experienced successful treatment (32.8 %). Overall, its use resulted in a clear delay in the time of treatment, so that according to our results, the use of LIPUS should be seen critically in long bone nonunions and use should be made on a case-by-case basis.

Operative versus nonoperative interventions for common fractures of the clavicle: a meta-analysis of randomized controlled trials

BACKGROUND

The popularity of surgery for acute displaced midshaft clavicle fractures has been fuelled by early randomized controlled trials (RCTs) showing improved rates of radiographic union and perceived functional benefits compared with nonoperative approaches. We performed a meta-analysis to determine the effect of operative and nonoperative interventions on the risk of secondary operation and complications and on long-term function.

METHODS

We search MEDLINE, Embase and the Cochrane Central Register of Controlled Trials for reports of relevant RCTs published to Mar. 7, 2014. Two reviewers assessed eligibility of potential reports and the risk of bias of included trials. The Grading of Recommendations Assessment, Development and Evaluation approach was used to summarize the quality of evidence for all outcomes.

RESULTS

We included 15 RCTs (9 trials comparing operative and nonoperative interventions, 5 comparing implants for operative treatment, and 1 comparing nonoperative treatments). Nonoperative treatments did not differ from operative treatments in the risk of secondary operation (risk ratio [RR] 1.16, 95% confidence interval [CI] 0.58 to 2.35) or all complications (RR 0.90, 95% CI 0.55 to 1.50). One in 4 patients had a complication regardless of the treatment approach. Differences in functional outcomes, although smaller than the threshold for minimal important differences at 1 year, favoured operative interventions (standardized mean difference 0.38, 95% CI 0 to 0.75). Evidence for the type of implant or approach to nonoperative treatment remained inconclusive.

INTERPRETATION

Current evidence does not support the routine use of internal fixation for the treatment of displaced midshaft clavicle fractures. Complication rates were high regardless of the treatment approach.

Fracture non-union epidemiology and treatment

Fracture non-union remains a clinical problem despite advances in the understanding of basic science and technology. Each fracture has a unique personality as does the patient suffering the injury. Thus, each case must be treated on an individual basis. This article defines the problem of fracture non-union and reports recent epidemiological studies. We discuss relevant risk factors and methods for assessing patients who have a tendency toward fracture non-union. There are many treatment options for patients with non-union, where a number of these modalities are still under review. We discuss current evidence with the use of bone morphogenic protein, platelet-rich plasma and low-intensity pulsed ultrasound to augment the treatment of fracture non-union.

The effects of low-intensity pulsed ultrasound and pulsed electromagnetic fields bone growth stimulation in acute fractures: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

The aim of this systematic review and meta-analysis was to evaluate the best currently available evidence from randomized controlled trials comparing pulsed electromagnetic fields (PEMF) or low-intensity pulsed ultrasound (LIPUS) bone growth stimulation with placebo for acute fractures.

MATERIALS AND METHODS

We performed a systematic literature search of the medical literature from 1980 to 2013 for randomized clinical trials concerning acute fractures in adults treated with PEMF or LIPUS. Two reviewers independently determined the strength of the included studies by assessing the risk of bias according to the criteria in the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Seven hundred and thirty-seven patients from 13 trials were included. Pooled results from 13 trials reporting proportion of nonunion showed no significant difference between PEMF or LIPUS and control. With regard to time to radiological union, we found heterogeneous results that significantly favoured PEMF or LIPUS bone growth stimulation only in non-operatively treated fractures or fractures of the upper limb. Furthermore, we found significant results that suggest that the use of PEMF or LIPUS in acute diaphyseal fractures may accelerate the time to clinical union.

CONCLUSIONS

Current evidence from randomized trials is insufficient to conclude a benefit of PEMF or LIPUS bone growth stimulation in reducing the incidence of nonunions when used for treatment in acute fractures. However, our systematic review and meta-analysis suggest that PEMF or LIPUS can be beneficial in the treatment of acute fractures regarding time to radiological and clinical union. PEMF and LIPUS significantly shorten time to radiological union for acute fractures undergoing non-operative treatment and acute fractures of the upper limb. Furthermore, PEMF or LIPUS bone growth stimulation accelerates the time to clinical union for acute diaphyseal fractures.

Ultrasound and shockwave therapy for acute fractures in adults

BACKGROUND

The morbidity and socioeconomic costs of fractures are considerable. The length of time to healing is an important factor in determining a person's recovery after a fracture. Ultrasound may have a therapeutic role in reducing the time to union after fracture. This is an update of a review previously published in February 2012.

OBJECTIVES

To assess the effects of low-intensity ultrasound (LIPUS), high-intensity focused ultrasound (HIFUS) and extracorporeal shockwave therapies (ECSW) as part of the treatment of acute fractures in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (2 June 2014), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2014, Issue 5), MEDLINE (1946 to May Week 3 2014), EMBASE (1980 to 2014 Week 22), trial registers and reference lists of articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials evaluating ultrasound treatment in the management of acute fractures in adults. Studies had to include participants over 18 years of age with acute fractures, reporting outcomes such as function; time to union; non-union; secondary procedures such as for fixation or delayed union or non-union; adverse effects; pain; costs; and patient adherence.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from the included studies. Treatment effects were assessed using mean differences, standardised mean differences or risk ratios using a fixed-effect model, except where there was substantial heterogeneity, when data were pooled using a random-effects model. Results from 'worst case' analyses, which gave more conservative estimates of treatment effects for time to fracture union, are reported in preference to those from 'as reported' analyses.

MAIN RESULTS

We included 12 studies, involving 622 participants with 648 fractures. Eight studies were randomised placebo-controlled trials, two were randomised controlled trials without placebo controls, one was a quasi-randomised placebo-controlled trial and one was a quasi-randomised controlled trial without placebo control. Eleven trials tested LIPUS and one trial tested ECSW. Four trials included participants with conservatively treated upper limb complete fractures and six trials included participants with lower limb complete fractures; these were surgically fixed in four trials. The remaining two trials reported results for conservatively treated tibial stress fractures.'Risk of bias' assessment of the included studies was hampered by the poor reporting of methods, frequently resulting in the risk of bias of individual domains being judged as 'unclear'. Both quasi-randomised studies were at high risk of bias, including selection and attrition bias. Three studies were at low risk of selection bias relating to allocation concealment the majority of studies were at low risk of performance bias as they employed a form of intervention blinding.Only limited data were available from three of only four studies reporting on functional outcome. One study of complete fractures found little evidence of a difference between the two groups in the time to return to work (mean difference (MD) 1.95 days favouring control, 95% confidence interval (CI) -2.18 to 6.08; 101 participants). Pooled data from two studies found LIPUS did not significantly affect the time to return to training or duty in soldiers or midshipmen with stress fractures (MD -8.55 days, 95% CI -22.71 to 5.61; 93 participants).We adopted a conservative strategy for data analysis that was more likely to underestimate than to overestimate a benefit of the intervention. After pooling results from eight studies (446 fractures), the data showed no statistically significant reduction in time to union of complete fractures treated with LIPUS (standardised mean difference (SMD) -0.47, 95% CI -1.14 to 0.20). This result could include a clinically important benefit or harm, and should be seen in the context of the highly significant statistical heterogeneity (I² = 90%). This heterogeneity was not explained by the a priori subgroup analyses (upper limb versus lower limb fracture, smoking status). An additional subgroup analysis comparing conservatively and operatively treated fractures raised the possibility that LIPUS may be effective in reducing healing time in conservatively managed fractures, but the test for subgroup differences did not confirm a significant difference between the subgroups.Pooled results from five of the eight trials (333 fractures) reporting proportion of delayed union or non-union showed no significant difference between LIPUS and control (10/168 versus 13/165; RR 0.75; 95% CI 0.24 to 2.28). Adverse effects directly associated with LIPUS and associated devices were found to be few and minor, and compliance with treatment was generally good. One study reporting on pain scores found no difference between groups at eight weeks (101 participants).One quasi-randomised study found no significant difference in non-union at 12 months between internal fixation supplemented with ECSW and internal fixation alone (3/27 versus 6/30; RR 0.56, 95% CI 0.15 to 2.01). There was a clinically small but statistically significant difference in the visual analogue scores for pain in favour of ECSW at three month follow-up (MD -0.80, 95% CI -1.23 to -0.37). The only reported complication was infection, with no significant difference between the two groups.

AUTHORS' CONCLUSIONS

While a potential benefit of ultrasound for the treatment of acute fractures in adults cannot be ruled out, the currently available evidence from a set of clinically heterogeneous trials is insufficient to support the routine use of this intervention in clinical practice. Future trials should record functional outcomes and follow-up all trial participants.

Low-intensity pulsed ultrasonography versus electrical stimulation for fracture healing: a systematic review and network meta-analysis

BACKGROUND

To best inform evidence-based patient care, it is often desirable to compare competing therapies. We performed a network meta-analysis to indirectly compare low intensity pulsed ultrasonography (LIPUS) with electrical stimulation (ESTIM) for fracture healing.

METHODS

We searched the reference lists of recent reviews evaluating LIPUS and ESTIM that included studies published up to 2011 from 4 electronic databases. We updated the searches of all electronic databases up to April 2012. Eligible trials were those that included patients with a fresh fracture or an existing delayed union or nonunion who were randomized to LIPUS or ESTIM as well as a control group. Two pairs of reviewers, independently and in duplicate, screened titles and abstracts, reviewed the full text of potentially eligible articles, extracted data and assessed study quality. We used standard and network meta-analytic techniques to synthesize the data.

RESULTS

Of the 27 eligible trials, 15 provided data for our analyses. In patients with a fresh fracture, there was a suggested benefit of LIPUS at 6 months (risk ratio [RR] 1.17, 95% confidence interval [CI] 0.97-1.41). In patients with an existing nonunion or delayed union, ESTIM had a suggested benefit over standard care on union rates at 3 months (RR 2.05, 95% CI 0.99-4.24). We found very low-quality evidence suggesting a potential benefit of LIPUS versus ESTIM in improving union rates at 6 months (RR 0.76, 95% CI 0.58-1.01) in fresh fracture populations.

CONCLUSION

To support our findings direct comparative trials with safeguards against bias assessing outcomes important to patients, such as functional recovery, are required.

Conservative interventions for treating middle third clavicle fractures in adolescents and adults

BACKGROUND

Clavicle (collarbone) fractures account for around 4% of all fractures; treatment of these fractures is usually non-surgical (conservative). Commonly used treatments are arm slings, strapping, figure-of-eight bandages and splints.This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To evaluate the effects of different methods for conservative (non-operative) treatment for acute (treated soon after injury) middle third clavicle fractures in adolescents and adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (2013, Issue 12), MEDLINE (from 1966), EMBASE (from 1980), LILACS (from 1982), trial registers, orthopaedic proceedings and reference lists of articles. We applied no language or publication restrictions. The date of the last search was 29 January 2014.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials testing conservative interventions for treating adolescents and adults with acute middle third clavicle fractures. The primary outcomes were shoulder function or disability, pain and treatment failure.

DATA COLLECTION AND ANALYSIS

At least two authors selected eligible trials, independently assessed risk of bias and cross-checked data extraction. We calculated risk ratios and 95% confidence intervals for dichotomous variables, and mean differences and 95% confidence intervals for continuous variables. There was no pooling of data.

MAIN RESULTS

We included three trials in this review with 354 participants. No new trials were included in this update.Very low quality evidence was available from two trials (234 participants) that compared the figure-of-eight bandage with an arm sling for treating acute middle third clavicle fractures. Both trials were underpowered and compromised by poor methodology. One trial found slightly higher pain levels in the bandage group at 15 days (mean difference 0.80, 95% confidence interval 0.34 to 1.26; visual analogue scale: 0 (no pain) to 10 (worst pain)); and the other trial reported greater discomfort during bandage wear. There were no significant differences between the two interventions in functional or other outcomes reported for either trial.Moderate quality evidence was available from the third trial (120 participants), which evaluated therapeutic ultrasound. This trial was at low risk of any type of bias but was underpowered. The trial found no statistically significant difference between low-intensity pulsed ultrasound and placebo in the time to clinical fracture healing (mean difference -0.32 days, 95% CI -5.85 to 5.21 days), nor in any of the other reported outcomes.

AUTHORS' CONCLUSIONS

There is limited evidence available from randomised controlled trials to determine which methods of conservative treatment are the most appropriate for acute middle third clavicle fractures in adolescents and adults. Further research is warranted.

Ultrasound stimulation increases proliferation of MC3T3-E1 preosteoblast-like cells

Background

Mechanical stimulation of bone increases bone mass and fracture healing, at least in part, through increases in proliferation of osteoblasts and osteoprogenitor cells. Researchers have previously performed in vitro studies of ultrasound-induced osteoblast proliferation but mostly used fixed ultrasound settings and have reported widely varying and inconclusive results. Here we critically investigated the effects of the excitation parameters of low-intensity pulsed ultrasound (LIPUS) stimulation on proliferation of MC3T3-E1 preosteoblastic cells in monolayer cultures.

Methods

We used a custom-designed ultrasound exposure system to vary the key ultrasound parameters—intensity, frequency and excitation duration. MC3T3-E1 cells were seeded in 12-well cell culture plates. Unless otherwise specified, treated cells, in groups of three, were excited twice for 10 min with an interval of 24 h in between after cell seeding. Proliferation rates of these cells were determined using BrdU and MTS assays 24 h after the last LIPUS excitation. All data are presented as the mean ± standard error. The statistical significance was determined using Student's two-sample two-tailed t tests.

Results

Using discrete LIPUS intensities ranging from 1 to 500 mW/cm² (SATA, spatial average-temporal average), we found that approximately 75 mW/cm² produced the greatest increase in osteoblast proliferation. Ultrasound exposures at higher intensity (approximately 465 mW/cm²) significantly reduced proliferation in MC3T3-E1 cells, suggesting that high-intensity pulsed ultrasound may increase apoptosis or loss of adhesion in these cells. Variation in LIPUS frequency from 0.5 MHz to 5 MHz indicated that osteoblast proliferation rate was not frequency dependent. We found no difference in the increase in proliferation rate if LIPUS was applied for 30 min/day or 10 min/day, indicating a habituation response.

Conclusion

This study concludes that a short-term stimulation with optimum intensity can enhance proliferation of preosteoblast-like bone cells that plays an important role in bone formation and accelerated fracture healing, also suggesting a possible therapeutic treatment for reduced bone mass.

Vocational rehabilitation for enhancing return-to-work in workers with traumatic upper limb injuries

BACKGROUND

Traumatic upper limb injury is a leading cause of work-related disability. After return-to-work (RTW), many survivors of injuries are able to regain a quality of life (QoL) comparable with the normal population. Since RTW plays an important role in economic productivity and regaining health-related QoL, enhancing RTW in workers with traumatic limb injuries is the primary goal of rehabilitation. Vocational rehabilitation has been adapted in the field of occupational safety and health to enhance the number of injured people returning to the labour market, prevent illness, increase well-being, and reduce disability.

OBJECTIVES

To assess the effects of vocational rehabilitation programs in enhancing RTW of workers with traumatic upper limb injuries.

SEARCH METHODS

We searched OSH UPDATE databases (CISDOC, HSELINE, International Bibliographic, NIOSHTIC, NIOSHTIC-2, RILOSH) (up to 10 December 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 11), MEDLINE through PubMed (up to 15 November 2012), EMBASE (up to 28 November 2012), CINAHL (up to 5 May 2013), PsycINFO (up to 7 December 2012), and handsearched the reference lists of relevant review articles.

SELECTION CRITERIA

We aimed to include all randomised controlled trials (RCTs) comparing vocational rehabilitation with an alternative (control) intervention such as standard rehabilitation, an incomplete form of the vocational rehabilitation intervention (such as with limited advice on RTW, referral information, or liaison with employer), or waiting-list controls.

DATA COLLECTION AND ANALYSIS

Two authors independently inspected abstracts and we obtained full papers when necessary. When the two authors disagreed about the inclusion of a study, we resolved disagreements by discussion. A third author arbitrated when necessary.

MAIN RESULTS

Our search identified 332 citations. Based on assessments of their titles and abstracts, we decided to evaluate the full texts of 15 citations. In the end, none of these 15 citations met our inclusion criteria.

AUTHORS' CONCLUSIONS

There is currently no high-level evidence to support or refute the efficacy of vocational rehabilitation in enhancing RTW in workers with traumatic upper limb injuries. Since vocational rehabilitation has frequently been provided to injured people in occupational settings with the aim of decreasing work disability, enhancing RTW, increasing productivity, and containing the welfare cost, further high-quality RCTs assessing the efficacy of vocational rehabilitation for workers with traumatic upper limb injury are needed to fill this gap in knowledge.

Bone regeneration by statin and low-intensity pulsed ultrasound (LIPUS) in rabbit nasal bone

OBJECTIVES

To compare bone regeneration between local implantation of statin and low-intensity pulsed ultrasound (LIPUS), and the combination of statin with LIPUS in rabbit nasal bone using histological and immunohistochemical methods.

STUDY DESIGN

Thirty-two adult male Japanese white rabbits (age: 12-16 weeks, weight: 2.5-3.0 kg) were used in this study. Two bone circular defects (5 mm in diameter) per rabbit were created in the nasal bone while preserving the nasal membrane. The two defects in each rabbit were filled with 2.5 mg/ml simvastatin in 0.2 ml water with an atelocollagen sponge (ACS) and ACS alone respectively. Sixteen rabbits (32 sides) received the LIPUS application; the remaining 16 rabbits (32 sides) did not. Therefore, the subjects composed of 4 groups, namely, (1) LIPUS + ACS + simvastatin (the LAS group), (2) LIPUS + ACS (the LA group), (3) ACS + simvastatin (the AS group) and (4) ACS alone (the A group). Four animals were killed in each period, at 1, 2, 4 and 8 weeks postoperative. The parts that had been operated on were removed and prepared for histological assessment. The expression of BMP-2 and the bone area ratio were evaluated using histological and immunohistochemical methods.

RESULTS

Bone square in the LAS group was significantly larger than that in the AS group after 1 (P < 0.0001) and 2 week (P = 0.0113). The bone square in the LA group was significantly larger than that in the A group after 1 (P < 0.0001) and 2 weeks (P = 0.0090). However, there was no significant difference between the LAS and LA groups. In the number of cells that stained positive for BMP-2, the LAS group was significantly larger than that in the AS group after 1 (P < 0.0001) and 2 weeks (P = 0.0113).

CONCLUSION

This study suggests that bone regeneration can be promoted by LIPUS alone and statin alone, respectively. However the combination use of LIPUS with statin does not differ from LIPUS alone or statin alone.

Ultrasound and shockwave therapy for acute fractures in adults

BACKGROUND

The morbidity and socioeconomic costs of fractures are considerable. The length of time to healing is an important factor in determining a patient's recovery after a fracture. Ultrasound may have a therapeutic role in reducing the time to union after fracture.

OBJECTIVES

To assess the effects of low intensity ultrasound (LIPUS), high intensity focused ultrasound (HIFUS) and extracorporeal shockwave therapies (ECSW) as part of the treatment of acute fractures in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (December 2011), the Cochrane Central Register of Controlled Trials (in The Cochrane Library 2011, Issue 4), MEDLINE (1950 to November Week 3 2011), EMBASE (1980 to 2011 Week 49), trial registers and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials evaluating ultrasound treatment in the management of acute fractures in adults. Studies including participants over 18 years of age with acute fractures, reporting functional outcomes, time to union, non-union, secondary procedures such as for fixation or delayed or non-union, adverse effects, pain, costs or patient adherence were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from the included studies. Treatment effects were assessed using mean differences or risk ratios and, where there was substantial heterogeneity, pooled using a random-effects model. Results from 'worst case' analyses, which gave more conservative estimates of treatment effects for time to fracture union, are reported in preference to those from 'as reported' analyses.

MAIN RESULTS

Twelve studies, involving 622 participants with 648 fractures, were included. Eight studies were randomised placebo-controlled trials, two studies were randomised controlled trials without placebo controls, one study was a quasi-randomised placebo controlled trial and the remaining study was a quasi-randomised controlled trial without placebo control. Eleven trials tested LIPUS and one trial tested ECSW. Four trials included participants with conservatively treated upper limb complete fractures and six trials included participants with lower limb complete fractures; these were surgically fixed in four trials. The remaining two trials reported results for conservatively treated tibial stress fractures.Very limited data from two complete fracture studies showed no difference between ultrasound and placebo control in functional outcome. Pooled estimates from two studies found LIPUS did not significantly affect the time to return to training or duty in soldiers or midshipmen with stress fractures (mean difference -8.55 days, 95% CI -22.71 to 5.61).Based on a 'worst case' analysis, which adjusted for incomplete data, pooled results from eight heterogeneous studies showed no statistically significant reduction in time to union of complete fractures treated with LIPUS (standardised mean difference -0.47, 95% CI -1.14 to 0.20). This result could include a clinically important benefit or harm, and should be seen in the context of the highly significant statistical heterogeneity (I² = 90%). This heterogeneity was not explained by the a priori subgroup analyses (upper limb versus lower limb fracture, smoking status). An additional subgroup analysis comparing conservatively and operatively treated fractures raised the possibility that LIPUS may be effective in reducing healing time in conservatively managed fractures, but the test for subgroup differences did not confirm a significant difference between the subgroups.Pooled results from eight trials reporting proportion of delayed union or non-union showed no significant difference between LIPUS and control. Adverse effects directly associated with LIPUS and associated devices were found to be few and minor, and compliance with treatment was generally good. One study reporting on pain scores found no difference between groups at eight weeks.One quasi-randomised study (59 fractures) found no significant difference between ECSW and no-placebo control groups in non-union at 12 months (risk ratio 0.56, 95% CI 0.15 to 2.01). There was a clinically small but statistically significant difference in the visual analogue scores for pain in favour of ECSW at three month follow-up. The only reported complication was infection, with no significant difference between the two groups.

AUTHORS' CONCLUSIONS

While a potential benefit of ultrasound for the treatment of acute fractures in adults cannot be ruled out, the currently available evidence from a set of clinically heterogeneous trials is insufficient to support the routine use of this intervention in clinical practice. Future trials should record functional outcomes and follow-up all trial participants.

Effects of ultrasound on osteotomy healing in a rabbit fracture model

This study investigated the effects of ultrasound (US) at different frequencies on fracture healing over a three-week period in a rabbit fibular fracture model. Forty-five adult New Zealand White rabbits were divided into five groups: a control group and four groups treated with US frequencies of 0.5, 1.0, 1.5 and 2.0 MHz (0.5 W/cm(2), 200-μs burst, pulsed 1:4). After anesthesia, transverse osteotomy was performed on the fibula bone. This was followed by intravital staining and fluorescence microscopic examination of new bone formation and biomechanical tests of torsional stiffness at the osteotomy site. Results showed that total new bone formation and torsional stiffness of the fibula were greater in all US-treated groups than in the control group. No significant difference was found between any of the four US-treated groups. The US treatment also enhanced bone growth of the sham-treated contralateral fracture site. These results suggest that US treatment at 0.5, 1.0, 1.5 or 2.0 MHz can enhance fracture healing in a rabbit model. Furthermore, the effects of US on fracture healing at present parameters might not be confined locally.

The evidence of low-intensity pulsed ultrasound for in vitro, animal and human fracture healing

BACKGROUND

Physical stimulation therapies are currently available to enhance fracture healing.

SOURCES OF DATA

A search of PubMed, Medline, CINAHL, DH data and Embase databases was performed using the keywords 'ultrasound' and 'fracture healing'.

AREAS OF AGREEMENT

The evidence in vitro and animal studies suggests that low-intensity pulsed ultrasound (LIPUS) produces significant osteoinductive effects, accelerating the healing process and improving the bone-bending strength.

AREAS OF CONTROVERSY

The evidence in human trials is controversial in fresh, stress fractures and in limb lengthening. LIPUS is effective in delayed unions, in smokers and in diabetic population.

GROWING POINTS

LIPUS is an alternative, less invasive form of treatment for complicated fractures, in patients with poor bone healing and may play a role in the management of large-scale bone defects producing substantial cost savings and decreasing associated disability.

AREAS TIMELY FOR DEVELOPING RESEARCH

There is heterogeneity among in vitro, animal studies and their application to human studies. Further randomized controlled trials of high methodological quality are needed.

Low-intensity ultrasound application in distal radius metaphyseal bone defects of dogs

We assessed the repair of transverse, 3-mm wide bone gaps created at the distal radius in 28 dogs that were randomly divided into two 14-animal groups; one was the control group and the other received a daily, 20-min application of low-intensity pulsed ultrasound for 100 days. Sequential radiographs, histomorphometrics, bone fluorescent histology and bone vascularity assessments found that all animals from both groups obtained a stage of hypertrophic-type nonunion with fibrocartilage tissue formation throughout the region of osteotomy. However, treated animals exhibited areas of endochondral ossification within the fibrocartilage region. There was no difference in type of vascularity or the newly formed bone process obtained by tetracycline labeling. Application of low-intensity ultrasound was not capable of significantly changing the reparative process and it may not be sufficiently powerful to overcome a combination of local deleterious effects on bone healing, created by gapping, excessive motion and periosteal resection.

Ultrasound for fracture healing: current evidence

Low-intensity pulsed ultrasound (LIPUS) is a relatively new technique for the acceleration of fracture healing in fresh fractures and nonunions. It has a frequency of 1.5 MHz, a signal burst width of 200 micros, a signal repetition frequency of 1 kHz, and an intensity of 30 mW/cm2. In 1994 and 1997, two milestone double-blind randomized controlled trials revealed the benefits of LIPUS for the acceleration of fracture healing in the tibia and radius. They showed that LIPUS accelerated the fracture healing rate from 24% to 42% for fresh fractures. Some literature, however, has shown no positive effects. The beneficial effect of acceleration of fracture healing by LIPUS is considered to be larger in the group of patients or fractures with potentially negative factors for fracture healing. The incidence of delayed union and nonunion is 5% to 10% of all fractures. For delayed union and nonunion, the overall success rate of LIPUS therapy is approximately 67% (humerus), 90% (radius/radius-ulna), 82% (femur), and 87% (tibia/tibia-fibula). LIPUS likely has the ability to enhance maturation of the callus in distraction osteogenesis and reduce the healing index. The critical role of LIPUS for fracture healing is still unknown because of the heterogeneity of results in clinical trials for fresh fractures and the lack of controlled trials for delayed unions and nonunions.

Low-intensity pulsed ultrasound-dependent osteoblast proliferation occurs by via activation of the P2Y receptor: role of the P2Y1 receptor

Low-intensity pulsed ultrasound (LIPUS) is commonly used in the treatment of fractures and nonunion-promoting acceleration of healing fractures. In this report, we investigated the implication of the P2 receptors in osteoblast proliferation induced with LIPUS treatment. We observed that ADP, ATP, UTP, and UDP promote osteoblast increase and an increase of intracellular Ca(2+), through activation of P2Y receptors. Osteoblasts' expression of the P2Y(1), P2Y(2), P2Y(4), P2Y(6), P2Y(11), P2Y(12), and P2Y(13) receptors was confirmed. In addition, the participation of the P2Y(1) receptor in osteoblast increase and the ADP-dependent increase of Ca(2+) concentration were shown. Furthermore, release of ATP/purines was induced by LIPUS treatment. Finally, LIPUS-dependent osteoblast increase was abolished in the presence of the Ca(2+) chelator (BAPTA), the inositol 1,4,5-trisphosphate receptor antagonist (2-APB), and the selective P2Y(1) receptor antagonist (MRS2179). In conclusion, LIPUS treatment induces osteoblastogenesis via the release of purines, such as ATP, activating P2Y receptors, mainly the P2Y(1) receptor.