Extracorporeal shock waves promote healing of collagenase-induced Achilles tendinitis and increase TGF-beta1 and IGF-I expression

Use of Human Placenta-Derived Cells in a Preclinical Model of Tendon Injury

BACKGROUND

Emerging data suggest that human cells derived from extraembryonic tissues may have favorable musculoskeletal repair properties. The purpose of this study was to determine whether the injection of human placenta-derived mesenchymal-like stromal cells, termed placental expanded cells (PLX-PAD), would improve tendon healing in a preclinical model of tendinopathy.

METHODS

Sixty male Sprague-Dawley rats underwent bilateral patellar tendon injection with either saline solution (control) or PLX-PAD cells (2 × 10 cells/100 µL) 6 days after collagenase injection to induce tendon degeneration. Animals were killed at specific time points for biomechanical, histological, and gene expression analyses of the healing patellar tendons.

RESULTS

Biomechanical testing 2 weeks after the collagenase injury demonstrated better biomechanical properties in the tendons treated with PLX-PAD cells. The load to failure of the PLX-PAD-treated tendons was higher than that of the saline-solution-treated controls at 2 weeks (77.01 ± 10.51 versus 58.87 ± 11.97 N, p = 0.01). There was no significant difference between the 2 groups at 4 weeks. There were no differences in stiffness at either time point. Semiquantitative histological analysis demonstrated no significant differences in collagen organization or cellularity between the PLX-PAD and saline-solution-treated tendons. Gene expression analysis demonstrated higher levels of interleukin-1β (IL-1β) and IL-6 early in the healing process in the PLX-PAD-treated tendons.

CONCLUSIONS

Human placenta-derived cell therapy induced an early inflammatory response and a transient beneficial effect on tendon failure load in a model of collagenase-induced tendon degeneration.

CLINICAL RELEVANCE

Human extraembryonic tissues, such as the placenta, are an emerging source of cells for musculoskeletal repair and may hold promise as a point-of-care cell therapy for tendon injuries.

Thermal pretreatment promotes the protective effect of HSP70 against tendon adhesion in tendon healing by increasing HSP70 expression

Tendon adhesion is a substantial challenge for tendon repair. Thermal pretreatment (TP) may decrease inflammation by upregulating heat shock proteins (HSPs). The present study intends to identify the function that TP serves when combined with HSP70 overexpression in tendon healing and adhesion in rats. Sprague‑Dawley male rats were used to establish a surgically ablative tendon postoperative suture model, and the positive expression of the HSP70 protein was measured using immunohistochemistry. Changes to the blood vessels and collagenous fiber, in addition to the maximum tensile strength and the tendon sliding distance, were detected under a microscope. Finally, HSP70, tumor growth factor β (TGF‑β), and insulin‑like growth factor 1 (IGF‑1) mRNA and protein levels were all determined by employing reverse transcription‑quantitative polymerase chain reaction and western blot analysis methods. The positive expression of the HSP70 protein increased following TP. Furthermore, TP reduced the infiltration of inflammatory cells and improved the collagenous arrangement, accompanied by an increased maximum tensile force and tendon gliding distance following surgery. In addition, TP increased the mRNA and protein expression levels of HSP70, TGF‑β and IGF‑1. Altogether, TP increases HSP70 expression, thereby reducing postoperative traumatic inflammation and establishing tendon adhesion and promoting tendon healing. Thus, TP may be a potential strategy for the treatment of tendon adhesion.

Power Doppler Ultrasound Findings before and after Focused Extracorporeal Shock Wave Therapy for Achilles Tendinopathy: A Pilot Study on Pain Reduction and Neovascularization Effect

Extracorporeal shock wave therapy (ESWT) has been found to have a positive effect in the treatment of pain in Achilles tendinopathy, although the exact mechanism is not yet completely understood. Among the mechanisms suggested to underlie ESWT effects are direct stimulation of healing, neovascularization and direct suppressive effects on nociceptors and hyperstimulation, which would block the gate-control system. The neovascularization observed in flogistic tissue is associated with stimulated nerve fibers around tendons and induces a painful condition. The objectives of the present study were to evaluate the effect of ESWT on pain and function in patients with non-insertional Achilles tendinopathy (NIAT) and to assess the neovascularization phenomenon using power Doppler ultrasound (PDU). Twelve patients with NIAT underwent five sessions of focused ESWT over 5 wk. Outcome measures were the visual analogue scale, the Victorian Institute of Sport Assessment-Achilles questionnaire and active dorsiflexion and plantar flexion ankle articular range of motion. Moreover, the patients' clinical impressions of treatment results after ESWT were investigated using the Roles and Maudsley score. Patients were assessed at baseline and 1 and 3 mo after treatment. They had a significant reduction in pain with improvement of arthrokinematic motion and functionality and a positive clinical impression of treatment outcome (50% of patients considered their clinical picture as good/excellent after 3 mo). However, the pulse Doppler ultrasound exam did not reveal neovascularization in 91.7% of the patients 1 and 2 mo after focused ESWT, and in some patients there was a reduction in blood vessels related to flogistic processes. The present observational study confirmed the efficacy of ESWT in pain reduction in NIAT, with a higher degree of patient satisfaction, although doubt persists over the neovascularization effect on the Achilles tendons treated.

Percutaneous soft tissue release performed using a blunt cannula in rabbits with chronic collagenase-induced Achilles tendinopathy

BACKGROUND

This study investigated the effects of percutaneous soft tissue release (PSTR) performed using a blunt cannula on (1) the inflammatory cells-count, (2) expressions of calcitonin gene-related peptide (CGRP) and (3) substance P (SP) in rabbits with chronic phase of collagenase-induced Achilles tendinopathy.

METHODS

Thirty-two adult male New Zealand rabbits were randomly divided into four groups: (1) collagenase and PSTR treatment; (2) collagenase and sham-operated PSTR treatment; (3) vehicle-only injection and PSTR treatment; and (4) vehicle-only injection and sham-operated PSTR treatment. Achilles tendon of adult male rabbits was injected with 10μl of collagenase under ultrasonography localization. After 30 days, PSTR was performed using an 18G beauty cosmetic blunt tip micro cannula needle to release the soft tissue and paratenon above the inflamed Achilles tendon. The treated tendons and spinal cords of L5-S2 were harvested 5days after treatment for histological assessment and immunohistochemical analysis.

RESULTS

Histopathological examination revealed that PSTR achieved significant reduction in hypercellularity with pronounced infiltration of immune cells at the site of paratenon in tendons injected with collagenase compared with sham operation (p<0.05). Immunohistochemical analysis also showed marked decrease in expression of CGRP in tendon and SP in dorsal horns after PSTR (p<0.05).

CONCLUSIONS

This study showed positive effects in an animal model of chronic tendinopathy, and can be considered a treatment option, but that further research is necessary to determine its role in clinical practice.

Effect of extracorporeal low-energy shock wave on diabetic gastroparesis in a rat model

BACKGROUND AND AIM

Delayed gastric emptying occurs in more than 50% of chronic diabetic patients, and this is associated with significant impairments in quality of life. Traditional therapy for delayed gastric emptying has focused on supportive treatment, and there is no significant effective therapy. The effect of low-energy shock wave on gastric motility is never studied. We investigated low-energy shock wave on gastric motility in a diabetic rat model.

METHODS

Twenty-eight male Wistar rats were studied and separated in three groups in randomized order as control, diabetic rats received shock wave, and diabetic rats received the sham procedure. Antral area and motility were recorded using the transabdominal ultrasound. Blood was taken for measurement of gastric motility peptides. Subjects were killed for immunohistochemical stain analysis of enteric plexus of the stomach.

RESULTS

We successfully induced 20 diabetic rats and set ultrasound for measuring rat gastric contract and emptying model and demonstrated that 6 weeks of low-energy shock wave could promote gastric contraction and emptying in diabetic rats. Moreover, we demonstrated that shock wave could increase defecation and feces and decrease serum cholesterol and triglycerol. However, no effect on glycohemoglobin and gastric motility peptides was recorded. In the immunohistochemical staining, shock wave increased expression of gastric myenteric neuron plexus.

CONCLUSION

Low-energy shock wave can increase gastric contraction and emptying by activating axonal regeneration and increasing myenteric plexus, but not related with motility peptides.

Prevention of arthrofibrosis during knee repair by extracorporeal shock wave therapy: Preliminary study in rabbits

INTRODUCTION

Surgery or trauma may induce extensive arthrofibrosis around joints and tendon for the restrictive range of motion. Although some approaches were proposed, this problem is not solved satisfactorily. Extracorporeal shock wave therapy (ESWT) has been used for orthopedic, musculoskeletal, and fibrotic disorders. Whether it could prevent the formation of arthrofibrosis during the joint repair is unknown.

METHODS

Intra-articular adhesions were created in the right knee of the rabbit by cortical bone shaving and subsequent cast immobilization. Arthrofibrosis in the control and ESWT group was evaluated and compared at week 4.

RESULTS

Macroscopic score of arthrofibrosis and contracture angle of the control group are significantly higher. Histologically, the apparent gap between patella and tibia, loose connective tissue, and much less density of the blood vessel are found in the ESWT group.

CONCLUSIONS

ESWT could noninvasively, effectively, and safely prevent the formation of arthrofibrosis during the knee repair.

Impacts of low-energy extracorporeal shockwave therapy on pain, pruritus, and health-related quality of life in patients with burn: A randomized placebo-controlled study

BACKGROUND

The management of post-burn pain and pruritus remain a potent challenge because of their bad effects on health-related quality of life (HRQOL). The main purpose of this study was to evaluate the impacts of low-energy extracorporeal shockwave therapy (low-energy ESWT) in the management of pain, pruritus, and HRQOL in patients with burn.

METHODS

Forty-five adult patients with burn, their age ranged from 18 to 55 years, were included in the study, they randomly assigned into 22 patients in the study group (low-energy ESWT) and 23 patients in the placebo group. The study group received low-energy ESWT (0.05-0.20mJ/mm², a frequency of 4Hz with total shocks from 1000 to 2000 shocks) once per week for 4 successive weeks, while the placebo group received ESWT without energy. Both groups received traditional physical therapy program of selective different exercises (respiratory, range of motion, endurance, strengthening, balance, mobilization, stretching, and gait training) 3days per week for 4 weeks. Numerical Rating Scale (NRS) for pain and for pruritus, Pressure Pain Threshold (PPT), 12-Item Pruritus Severity Scale (12-PSS), and Burn Specific Health Scale-Brief (BSHS-B) were measured before and after treatment procedures in both groups.

RESULTS

NRS were decreased significantly in the study group than in the placebo group (P<0.05). PPT, 12-PSS, and BSHS-B scores were improved more significantly in the study group than in the placebo group (P<0.05) while body image and burn associated issues were improved at the same level in both groups (P>0.05).

CONCLUSION

The findings suggest that low-energy ESWT with traditional regular physical therapy may relive post-burn pain and pruritus, and improve HRQOL, particularly in adult patients with burn.

Calcific tendinopathy of the shoulder: clinical perspectives into the mechanisms, pathogenesis, and treatment

Calcific tendinopathy (CT) of the shoulder is a common, painful condition characterized by the presence of calcium deposits in the rotator cuff tendons. Current theories indicate that CT may be the result of a cell-mediated process in which, after a stage of calcium deposition, calcifications are spontaneously resorbed. However, in a minority of cases, this self-healing process is somehow disrupted, resulting in symptoms. Recent literature shows an emerging role of biological and genetic factors underlying CT. This new evidence could supplement the classic mechanical theory of rotator cuff tendinopathy complicated by calcium precipitation, and it may also explain why the majority of the therapies currently in use are only able to provide partially satisfactory outcomes. This review aims to summarize the current knowledge about the pathological processes underlying CT of the shoulder and thereby justify the quest for advanced biological treatments of this condition when it becomes symptomatic.

Effect of Shockwave Treatment for Management of Upper and Lower Extremity Musculoskeletal Conditions: A Narrative Review

Extracorporeal shockwave therapy (ESWT) is a technology that was first introduced into clinical practice in 1982 for urologic conditions. Subsequent clinical applications in musculoskeletal conditions have been described in treatment of plantar fasciopathy, both upper and lower extremity tendinopathies, greater trochanteric pain syndrome, medial tibial stress syndrome, management of nonunion fractures, and joint disease including avascular necrosis. The aim of this review is to summarize the current understanding of treatment of musculoskeletal conditions with ESWT, accounting for differences in treatment protocol and energy levels. Complications from ESWT are rare but include 2 reported cases of injury to bone and Achilles tendon rupture in older adults using focused shockwave. Collectively, studies suggest ESWT is generally well-tolerated treatment strategy for multiple musculoskeletal conditions commonly seen in clinical practice. LEVEL OF EVIDENCE: III.

Recent advances in conservative and surgical treatment options of common equine foot problems

Foot problems are very common causes of lameness in horses. With the recent diagnostic advances to evaluate and treat foot pathology as well as to monitor response to therapy, it is now possible to more accurately evaluate the effectiveness of many of these treatments. This review details some of the recent advances of the most common conservative and surgical treatment options for foot problems in horses, including an overview of evidence on the efficacy to support the use of these treatment options and on factors that may affect prognosis.

Extracorporeal Shock Wave Therapy in Acute Injury Care: A Systematic Review

Objectives:

We provide a systematic review of the literature to identify clinical studies assessing the effects of extracorporeal shock wave therapy (ESWT) on acutely injured tissues of human subjects, also highlighting the biological mechanisms by which the technique is proposed to promote the processes of early tissue repair. Special attention is also paid to the progress of research in animal models.

Method:

A systematic review of the literature on ESWT of acute injuries of bone and soft tissue as available in the PubMed/MEDLINE, Cochrane CENTRAL, SPORTDiscus, and CINAHL databases up to December 2017 was conducted.

Results:

A total of 10 studies were included. There is some evidence for the application of ESWT in an early postacute injury phase. Most studies report benefits with no or minimal side effects. However, different types of treated tissues and wounds (varying cause and severity) and resulting heterogeneity in study design and outcome measurement make it difficult to compare studies. The picture of knowledge remains limited by an apparent lack of data on optimal treatment timing and on tissue- and injury-specific parameters.

Conclusions:

Although the amount of studies to date is still limited, recent clinical research has presented first successful steps to introduce ESWT as a means of treatment in acute injury care. Therefore, on the basis of the analyzed data, further testing is encouraged to validate optimal timing, physical settings, and possible long-term effects to exclude potential risks.

Tendinopathy: injury, repair, and current exploration

Both acute and chronic tendinopathy result in high morbidity, requiring management that is often lengthy and expensive. However, limited and conflicting scientific evidence surrounding current management options has presented a challenge when trying to identify the best treatment for tendinopathy. As a result of shortcomings of current treatments, response to available therapies is often poor, resulting in frustration in both patients and physicians. Due to a lack of understanding of basic tendon-cell biology, further scientific investigation is needed in the field for the development of biological solutions. Optimization of new delivery systems and therapies that spatially and temporally mimic normal tendon physiology hold promise for clinical application. This review focuses on the clinical importance of tendinopathy, the structure of healthy tendons, tendon injury, and healing, and a discussion of current approaches for treatment that highlight the need for the development of new nonsurgical interventions.

Novel animal model for Achilles tendinopathy: Controlled experimental study of serial injections of collagenase in rabbits

Our goal was to develop a novel technique for inducing Achilles tendinopathy in animal models which more accurately represents the progressive histological and biomechanical characteristic of chronic Achilles tendinopathy in humans. In this animal research study, forty-five rabbits were randomly assigned to three groups and given bilateral Achilles injections. Low dose (LD group) (n = 18) underwent a novel technique with three low-dose (0.1mg) injections of collagenase that were separated by two weeks, the high dose group (HD) (n = 18) underwent traditional single high-dose (0.3mg) injections, and the third group were controls (n = 9). Six rabbits were sacrificed from each experimental group (LD and HD) at 10, 12 and 16 weeks. Control animals were sacrificed after 16 weeks. Histological and biomechanical properties were then compared in all three groups. At 10 weeks, Bonar score and tendon cross sectional area was highest in HD group, with impaired biomechanical properties compared to LD group. At 12 weeks, Bonar score was higher in LD group, with similar biomechanical findings when compared to HD group. After 16 weeks, Bonar score was significantly increased for both LD group (11,8±2,28) and HD group (5,6±2,51), when compared to controls (2±0,76). LD group showed more pronounced histological and biomechanical findings, including cross sectional area of the tendon, Young’s modulus, yield stress and ultimate tensile strength. In conclusion, Achilles tendinopathy in animal models that were induced by serial injections of low-dose collagenase showed more pronounced histological and biomechanical findings after 16 weeks than traditional techniques, mimicking better the progressive and chronic characteristic of the tendinopathy in humans.

Platelet-Rich Plasma Injections as a Treatment for Refractory Patellar Tendinosis: A Meta-Analysis of Randomised Trials

Purpose

Patellar tendinosis (PT) is a common condition amongst athletes. In this study, we perform a meta-analysis on randomised controlled trials (RCTs) to evaluate the use of platelet-rich plasma (PRP) for refractory PT.

Methods

A literature search was undertaken in various databases from their year of inception to October 2015. The primary outcome measure was the Victorian Institute of Sports Assessment-Patella (VISA-P) score.

Results

We identified 2 RCTs comparing PRP injections to alternative treatment options (extracorporeal shockwave therapy [ESWT] and dry needling of the tendon). Meta-analysis showed no significant difference in mean VISA-P scores between PRP injection and control at early assessment (2 or 3 months; estimated difference in means, 11.9; standard error [SE], 7.4; 95% confidence interval [CI], -2.7 to 26.4; p=0.109). However, PRP was statistically better than control with regards to VISA-P scores at longer follow-up (6 months or longer; estimated difference in means, 12.7; SE, 4.4; 95% CI, 4.1 to 21.3; p=0.004).

Conclusions

There is a paucity of RCTs evaluating the role of PRP in PT. Our results suggest that, based on limited evidence, PRP is superior over other established non-surgical treatments (dry needling and ESWT) for refractory PT. Larger RCTs may allow better characterisation of the role of PRP in this condition.

Tenomodulin highly expressing MSCs as a better cell source for tendon injury healing

Tendon injuries are common orthopedic problems which may cause severe morbidity. MSCs (mesenchymal stem cells) have shown promising effect on tissue engineering and have been used for the treatment of tendon injury. But the low tenogenic differentiation capacity of MSCs have hindered their application. In the present study, we have constructed the Tenomodulin (Tnmd) promoter-driven GFP expression lentiviral plasmid. After transduced into BMSCs, the expression of GFP was used to select BMSCs highly expressing Tnmd by flow cytometry. We found that MSCs with higher level of Tnmd expression had stronger tenogenic differentiation ability. Furthermore, RNA sequencing was performed to identify the molecular difference between BMSCs expressing higher and lower levels of Tnmd. And finally we demonstrated that GDF7 was upregulated in BMSCs highly expressing Tnmd and played an vital role in promoting tenogenic differentiation of BMSCs. GDF7 was mainly accounted for the elevated tenogenic differentiation ability of BMSCs with higher Tnmd expression as silencing the endogenous GDF7 significantly inhibited tenogenesis in BMSCs. In addition, the effect of BMSCs with higher Tnmd level on tendon healing was evaluated by a rat patellar tendon injury model. Taken together, our study showed that Tnmd could be used as an ideal cell surface marker to select cells with higher tenogenic differentiation ability from BMSCs, and GDF7 was indispensable for tenogenesis of MSCs.

Low-energy versus middle-energy extracorporeal shockwave therapy for the treatment of snapping scapula bursitis

OBJECTIVE

Extracorporeal shockwave therapy (ESWT) has been used successfully in treatment of musculoskeletal disorders. Our objective was to assess the effectiveness of low versus middle-energy ESWT on snapping scapula bursitis.

METHODS

Thirty-five patients, divided into two groups, group (L), received low-energy ESWT, group (M) received middle-energy ESWT. Groups were evaluated at 1,3,6 and 12 months using the Visual Analogue Scale (VAS), the Constant-Murley scoring (CMS) and the Roles and Maudsley criteria.

RESULTS

In groups (L) and (M), VAS average values after 1,3,6 months and one year were (43±5.17, 38±4.33, 28±4.18 and 19±3.39) and (37±4.85, 26±4.74, 21±4.45 and 7±3.42) respectively. At six and twelve months, statistical difference was detected, P (0.034, 0.026) respectively. After one year of completing the treatment, the average values of CMS were (83.5±6.44 and 91±5.33) respectively, P=0.046. Roles and Maudsley criteria demonstrated that, patients in group (L), 6 (35%) excellent, 5 (29%) good, 4 (24%) acceptable and 2 (12%) had poor results. Whereas, patients in group (M), 11 (61%) excellent, 3 (17%) good, 3 (17%) acceptable and 1 (5%) had poor results.

CONCLUSION

Although low-energy ESWT showed good early-term results, but middle-energy ESWT protocol demonstrated better early-term, Mid-term, and late-term results.

Non-insertional Achilles tendinopathy

Non-insertional Achilles tendinopathy is a degenerative condition characterised by pain on activity.Eccentric stretching is the most effective treatment.Surgical treatment is reserved for recalcitrant cases.Minimally-invasive and tendinoscopic treatments are showing promising results. Cite this article: Pearce CJ, Tan A. Non-insertional Achilles tendinopathy. EFORT Open Rev 2016;1:383-390. DOI: 10.1302/2058-5241.1.160024.

Extracorporeal Shock Wave Therapy Accelerates Regeneration After Acute Skeletal Muscle Injury

BACKGROUND

Muscle injuries are among the most common sports-related lesions in athletes; however, optimal treatment remains obscure. Extracorporeal shock wave therapy (ESWT) may be a promising approach in this context, because it has gained increasing importance in tissue regeneration in various medical fields.

HYPOTHESIS

ESWT stimulates and accelerates regenerative processes of acute muscle injuries.

STUDY DESIGN

Controlled laboratory study.

METHODS

Adult Sprague-Dawley rats were divided into 4 experimental groups (2 ESWT+ groups and 2 ESWT- groups) as well as an uninjured control group (n ≥ 6 in each group). An acute cardiotoxin-induced injury was set into the quadriceps femoris muscle of rats in the experimental groups. A single ESWT session was administered to injured muscles of the ESWT+ groups 1 day after injury, whereas ESWT- groups received no further treatment. At 4 and 7 days after injury, 1 each of the ESWT+ and ESWT- groups was euthanized. Regenerating lesions were excised and analyzed by histomorphometry and immunohistochemistry to assess fiber size, myonuclear content, and recruitment of satellite cells.

RESULTS

The size and myonuclear content of regenerating fibers in ESWT+ muscle was significantly increased compared with ESWT- muscle fibers at both 4 and 7 days after injury. Similarly, at both time points, ESWT+ muscles exhibited significantly higher contents of pax7-positive satellite cells, mitotically active H3P⁺ cells, and, of cells expressing the myogenic regulatory factors, myoD and myogenin, indicating enhanced proliferation and differentiation rates of satellite cells after ESWT. Mitotic activity at 4 days after injury was doubled in ESWT+ compared with ESWT- muscles.

CONCLUSION

ESWT stimulates regeneration of skeletal muscle tissue and accelerates repair processes.

CLINICAL RELEVANCE

We provide evidence for accelerated regeneration of damaged skeletal muscle after ESWT. Although further studies are necessary, our findings support the view that ESWT is an effective method to improve muscle healing, with special relevance to sports injuries.

An in vitro scratch tendon tissue injury model: effects of high frequency low magnitude loading

The healing process of ruptured tendons is suboptimal, taking months to achieve tissue with inferior properties to healthy tendon. Mechanical loading has been shown to positively influence tendon healing. However, high frequency low magnitude (HFLM) loads, which have shown promise in maintaining healthy tendon properties, have not been studied with in vitro injury models. Here, we present and validate an in vitro scratch tendon tissue injury model to investigate effects of HFLM loading on the properties of injured rat tail tendon fascicles (RTTFs). A longitudinal tendon tear was simulated using a needle aseptically to scratch a defined length along individual RTTFs. Tissue viability, biomechanical, and biochemical parameters were investigated before and 7 days after culture . The effects of static, HFLM (20 Hz), and low frequency (1 Hz) cyclic loading or no load were also investigated. Tendon viability was confirmed in damaged RTTFs after 7 days of culture, and the effects of a 0.77 ± 0.06 cm scratch on the mechanical property (tangent modulus) and tissue metabolism in damaged tendons were consistent, showing significant damage severity compared with intact tendons. Damaged tendon fascicles receiving HFLM (20 Hz) loads displayed significantly higher mean tangent modulus than unloaded damaged tendons (212.7 ± 14.94 v 92.7 ± 15.59 MPa), and damaged tendons receiving static loading (117.9 ± 10.65 MPa). HFLM stimulation maintained metabolic activity in 7-day cultured damaged tendons at similar levels to fresh tendons immediately following damage. Only damaged tendons receiving HFLM loads showed significantly higher metabolism than unloaded damaged tendons (relative fluorescence units -7021 ± 635.9 v 3745.1 ± 641.7). These validation data support the use of the custom-made in vitro injury model for investigating the potential of HFLM loading interventions in treating damaged tendons.

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.

Outcome of Extracorporeal Shock Wave Therapy for Insertional Achilles Tendinopathy with and without Haglund's Deformity

Purpose. To compare the results of extracorporeal shock wave therapy (ESWT) for insertional Achilles tendinopathy (IAT) with or without Haglund's deformity. Methods. Between September 2014 and May 2015, all patients who underwent ESWT were retrospectively enrolled in this study. A total of 67 patients were available for follow-up and assigned into nondeformtiy group (n = 37) and deformtiy group (n = 30). Clinical outcomes were evaluated by VISA-A Score and 6-point Likert scale. Results. The VISA-A score increased in both groups, from 49.57 ± 9.98 at baseline to 83.86 ± 8.59 at 14.5 ± 7.2 months after treatment in nondeformity group (P < 0.001) and from 48.70 ± 9.38 at baseline to 67.78 ± 11.35 at 15.3 ± 6.7 months after treatment in deformity group (P < 0.001). However, there was a greater improvement in VISA-A Score for the nondeformity group compared with deformity group (P = 0.005). For the 6-point Likert scale, there were decreases from 3.92 ± 0.80 at baseline to 1.57 ± 0.73 at the follow-up time point in nondeformity group (P < 0.001) and from 4.0 ± 0.76 at baseline to 2.37 ± 1.03 at the follow-up time point in deformity group (P < 0.001). There was no significant difference in improvement of the 6-point Likert scale between both groups (P = 0.062). Conclusions. ESWT resulted in greater clinical outcomes in patients without Haglund's deformity compared with patients with Haglund's deformity.

Utility of Ultrasonography in Assessing the Effectiveness of Extracorporeal Shock Wave Therapy in Insertional Achilles Tendinopathy

Introduction. The aim of this study was to investigate the utility of ultrasonography (US) for predicting and assessing the effectiveness of extracorporeal shock wave therapy (ESWT) in insertional Achilles tendinopathy (IAT). Methods. A total of 42 patients with an established diagnosis of chronic IAT were examined by US before ESWT and at 4 weeks and 12 weeks after ESWT. The thickness and cross-sectional area (CSA) of the Achilles tendon, size of calcific plaques, tendon structure score, and neovascularization score were measured at each time point. Results. After therapy, Victorian Institute of Sport Assessment-Achilles (VISA-A) scores increased significantly, and the size of calcific plaques decreased (P < 0.05). Neovascularization scores increased at the 4th week and then decreased at the 12th week (P < 0.05). The thickness, CSA, and structure of the Achilles tendon did not change. Variables observed by US at baseline were not associated with changes in VISA-A scores at follow-up. However, the changes in calcific plaque size and neovascularization scores were related to the improvement of VISA-A scores between pre- and posttherapy (P < 0.01). Conclusion. Ultrasonography can reveal some changes in the insertion of the Achilles tendon after ESWT, but the outcome of ESWT in IAT cannot be predicted by the variables observed by US.

Shear Wave Measurements for Evaluation of Tendon Diseases

This paper investigated the feasibility of using supersonic shear wave measurements to quantitatively differentiate normal and damaged tendons based on their mechanical properties. Five freshly harvested porcine tendons excised from pig legs were used. Tendon damage was induced by incubating the tendons with a 1% w/v collagenase solution. Values of shear modulus were derived both by a time-of-flight (TOF) approach and a transverse isotropic plate model (TI-model). The results show that as the preload applied to the tendon increased from 0 to 3 N, the mean shear modulus derived based on the TOF approach, the TI-model, and Young's modulus estimated from mechanical testing increased from 14.6 to 89.9 kPa, 53.9 to 348 kPa, and from 1.45 to 10.36 MPa, respectively, in untreated tendons, and from 8.4 to 67 kPa, 28 to 258 kPa, and from 0.93 to 7.2 MPa in collagenase-treated tendons. Both the TOF approach and the TI-model correlated well with the changes in Young's modulus. Although there is bias on the estimation of shear modulus using the TOF approach, it still provides statistical significance to differentiate normal and damaged tendons. Our data indicate that supersonic shear wave imaging is a valuable imaging technique to assess tendon stiffness dynamics and characterize normal and collagenase-damaged tendons.

Is Extracorporeal Shockwave Therapy Combined With Isokinetic Exercise More Effective Than Extracorporeal Shockwave Therapy Alone for Subacromial Impingement Syndrome? A Randomized Clinical Trial

Study Design Single-blind randomized trial. Background Extracorporeal shockwave therapy (ESWT) has been shown to produce good results in the treatment of subacromial impingement syndrome (SAIS). The efficacy of a combined administration of ESWT and isokinetic exercise (IE) has not yet been studied. Objectives To evaluate the efficacy of focused ESWT combined with IE for the rotator cuff versus focused ESWT alone in the treatment of SAIS. The secondary objective was to assess the isokinetic torque recovery (external rotation at 210°/s, 180°/s, and 120°/s). Methods Thirty participants with SAIS were randomly assigned to a focused-ESWT group or focused ESWT-plus-IE group. Subjects of both groups received 3 treatment sessions of focused ESWT over a period of 10 days. Participants in the second group also received IE for 10 therapy sessions. Outcome measures were the Constant-Murley score (CMS), the visual analog scale (VAS), and isokinetic parameters (peak torque and total work calculated from 5 repetitions) measured with the isokinetic test. Subjects were assessed at baseline, 10 days after the last treatment session with focused ESWT, and after 2 months of follow-up. Results At 2 months posttreatment, participants in the focused ESWT-plus-IE group showed significantly less pain (focused-ESWT VAS, 3.4 ± 0.8 versus focused ESWT-plus-IE VAS, 1.5 ± 0.5; P<.001) and greater improvement in functionality (focused-ESWT CMS, 75.9 ± 6.7 versus focused ESWT-plus-IE CMS, 92.1 ± 6.3; P<.001) and muscle endurance than the subjects in the focused-ESWT group. Conclusion In subjects with SAIS, combined administration of focused ESWT and IE for the rotator cuff resulted in greater reduction of pain, as well as superior functional recovery and muscle endurance in the short to medium term, compared with ESWT alone. Level of evidence Therapy, 2b.

TRIAL REGISTRATION

unregistered 2011 trial. J Orthop Sports Phys Ther 2016;46(9):714-725. Epub 5 Aug 2016. doi:10.2519/jospt.2016.4629.

Extracorporeal shockwave therapy (ESWT) for refractory Achilles tendinopathy: A prospective audit with 2-year follow up

BACKGROUND

Achilles tendinopathy (AT) represents a triad of tendon pain, swelling and impaired performance. Extracorporeal shockwave therapy (ESWT) has been endorsed by the National Institute for Health and Care Excellence (NICE) for refractory AT. This audit investigates the long-term outcomes of patients treated with ESWT for refractory AT.

METHODS

Forty-six patients treated with ESWT for AT between October 2010 and August 2011 completed visual analogue, satisfaction scores and functional assessment questionnaires over two years. Patients were subdivided into two groups depending on whether their AT was insertional (IAT) or non-insertional (NAT).

RESULTS

Forty-six patients (mean age 58 years) completed all treatments and full 2 year follow up. There was significant improvement in pain at rest, on activity and of function within both NAT and IAT groups over the two-year period. Satisfaction scores were significant in the NAT group but not in the IAT group.

CONCLUSIONS

ESWT appears to be of benefit in the long term improvement of pain at rest, on activity and functional outcome in patients with refractory AT. However, subjective patient opinion may not match the perceived clinical outcome observed in this audit in all patients and individuals should be counselled regarding this prior to treatment.

Shock wave as biological therapeutic tool: From mechanical stimulation to recovery and healing, through mechanotransduction

Extracorporeal Shock Wave Therapy (ESWT) is a form of "mechanotherapy", that, from its original applications as urological lithotripsy, gained the field of musculo-skeletal diseases as Orthotripsy (mainly tendinopaties and bone regenerative disorders) and Regenerative Medicine as well. The mechanisms of action of Shock Waves (SW), when applied in non-urological indications, are not related to the direct mechanical effect, but to the different pathways of biological reactions, that derive from that acoustic stimulations, through "mechano-transduction". So, the "mechanical model" of urological lithotripsy has been substituted by a "biological model", also supported by current knowledge in "mechanobiology", the emerging multidisciplinary field of science that investigates how physical forces and changes in cell/tissue mechanics can influence the tissue development, physiology and diseases. Although some details are still under study, it is known that SW are able to relief pain, as well to positively regulate inflammation (probably as immunomodulator), to induce neoangiogenesis and stem cells activities, thus improving tissue regeneration and healing. ESWT can be nowadays considered an effective, safe, versatile, repeatable, noninvasive therapy for the treatment of many musculo-skeletal diseases, and for some pathological conditions where regenerative effects are desirable, especially when some other noninvasive/conservative therapies have failed. Moreover, based on the current knowledge in SW mechanobiology, it seems possible to foresee new interesting and promising applications in the fields of Regenerative Medicine, tissue engineering and cell therapies.

Mechanical Stimulation (Pulsed Electromagnetic Fields "PEMF" and Extracorporeal Shock Wave Therapy "ESWT") and Tendon Regeneration: A Possible Alternative

The pathogenesis of tendon degeneration and tendinopathy is still partially unclear. However, an active role of metalloproteinases (MMP), growth factors, such as vascular endothelial growth factor (VEGF) and a crucial role of inflammatory elements and cytokines was demonstrated. Mechanical stimulation may play a role in regulation of inflammation. In vitro studies demonstrated that both pulsed electromagnetic fields (PEMF) and extracorporeal shock wave therapy (ESWT) increased the expression of pro-inflammatory cytokine such as interleukin (IL-6 and IL-10). Moreover, ESWT increases the expression of growth factors, such as transforming growth factor β(TGF-β), (VEGF), and insulin-like growth factor 1 (IGF1), as well as the synthesis of collagen I fibers. These pre-clinical results, in association with several clinical studies, suggest a potential effectiveness of ESWT for tendinopathy treatment. Recently PEMF gained popularity as adjuvant for fracture healing and bone regeneration. Similarly to ESWT, the mechanical stimulation obtained using PEMFs may play a role for treatment of tendinopathy and for tendon regeneration, increasing in vitro TGF-β production, as well as scleraxis and collagen I gene expression. In this manuscript the rational of mechanical stimulations and the clinical studies on the efficacy of extracorporeal shock wave (ESW) and PEMF will be discussed. However, no clear evidence of a clinical value of ESW and PEMF has been found in literature with regards to the treatment of tendinopathy in human, so further clinical trials are needed to confirm the promising hypotheses concerning the effectiveness of ESWT and PEMF mechanical stimulation.

The effect of dry needling and treadmill running on inducing pathological changes in rat Achilles tendon

Achilles tendinopathy is a common degenerative condition without a definitive treatment. An adequate chronic animal model of Achilles tendinopathy has not yet been developed. The purpose of this study was to evaluate the individual and combined effects of dry needling and treadmill running on the Achilles tendon of rats. Percutaneous dry needling, designed to physically replicate microrupture of collagen fibers in overloaded tendons, was performed on the right Achilles tendon of 80 Sprague-Dawley rats. The rats were randomly divided into two groups: a treadmill group, which included rats that underwent daily uphill treadmill running (n = 40), and a cage group, which included rats that could move freely within their cages (n = 40). At the end of weeks 1 and 4, 20 rats from each group were sacrificed, and bilateral Achilles tendons were collected. The harvested tendons were subjected to mechanical testing and histological analysis. Dry needling induced histological and mechanical changes in the Achilles tendons at week 1, and the changes persisted at week 4. The needled Achilles tendons of the treadmill group tended to show more severe histological and mechanical changes than those of the cage group, although these differences were not statistically significant. Dry needling combined with free cage activity or treadmill running produced tendinopathy-like changes in rat Achilles tendons up to 4 weeks after injury. Dry needling is an easy procedure with a short induction period and a high success rate, suggesting it may have relevance in the design of an Achilles tendinopathy model.

Extracorporeal shock wave therapy vs cryoultrasound therapy in the treatment of chronic lateral epicondylitis. One year follow up study

BACKGROUND

the purpose of this study is to compare the therapeutic effects of extracorporeal shock wave therapy (ESWT) to those of cryoultrasound (Cryo-US) therapy in chronic lateral epicondylitis during a 12-month period.

METHODS

single-blinded, randomized, controlled study of 80 participants treated for chronic LE with 3 ESWT sessions at 48/72-hours intervals (n=40) or 12 Cryo-US therapy sessions (4 sessions per week) (n=40). VAS and satisfactory results, considered as the sum of excellent and good scores in the Roles and Maudsley score, were used as outcome measures at baseline and 3, 6 and 12 months post-treatment.

RESULTS

the results show statistically significant differences in VAS between the two groups at 6 (p<0.001) and 12 months (p<0.001) in favour of the ESWT Group. At 12 months, a difference of more than 2 points in the VAS between the two groups is demonstrated in favour of the ESWT Group. Considering satisfactory results, significant differences between the two groups are observed at 6 (p=0.003) and 12 months (p <0.001) in favour of the ESWT Group where patients achieve a satisfactory rate over 50%.

CONCLUSIONS

ESWT has better clinical therapeutic results at 6- and 12-month follow-up as compared to Cryo-US therapy.

LEVEL OF EVIDENCE

1B.

Low-intensity pulsed ultrasound stimulates matrix metabolism of human annulus fibrosus cells mediated by transforming growth factor β1 and extracellular signal-regulated kinase pathway

PURPOSE

There are limited strategies to restore the damaged annulus fibrosus (AF) of the intervertebral disc. Low-intensity pulsed ultrasound (LIPUS) has positive effects on the proliferation of several types of cells and the repair of damage tissue in vivo. However, scientific evidence of therapeutic effects of LIPUS on AF cells remains limited. The purpose of this study is to evaluate the feasibility of applying LIPUS to the repair of the AF.

MATERIALS AND METHODS

We used an in vitro model of human AF cells subjected to LIPUS stimulation to examine its effects on cell proliferation and matrix metabolism. Cell viability, synthesis of collagen and glycosaminoglycan (GAG), expression of matrix metalloproteinases (MMPs) and transforming growth factor β1 and pathways involving mitogen-activated protein kinases (MAPKs) were investigated.

RESULTS

LIPUS significantly enhanced proliferation of AF cells after 5 days of treatment. LIPUS with an intensity of 0.5 W/cm(2) increased the collagen and GAG synthesis and decreased the expressions of MMP-1 and -3 of human AF cells. Real-time polymerase chain reactions and western blotting analysis revealed that LIPUS could increase transforming growth factor β1 (TGF-β1) and activate extracellular signal-regulated kinase (ERK) pathway. In addition, TGF-β receptor kinase inhibitor could suppress the ultrasound-induced alterations in cell viability and matrix metabolism.

CONCLUSIONS

The findings suggested that LIPUS could be useful as a physical stimulation of cell metabolism for the repair of the AF.

Percutaneous ultrasonic debridement of tendinopathy-a pilot Achilles rabbit model

Background

Tendinopathy is a common clinical pathology, with mixed treatment results, especially when chronic. In this study, we examine the effects of an ultrasonic debridement modality in a rabbit tendinopathy model.

We asked four questions: 1) Was it possible to create and visualize with ultrasound a tendinopathy lesion in a rabbit Achilles tendon? 2) Was it possible to guide a 19-gauge ultrasonic probe into the tendinopathy lesion? 3) Following ultrasonic treatment, was tendinopathy debris histologically present? and 4) Was the collagen profile qualitatively and quantitatively normalized following treatment?

Methods

Skeletally mature female New Zealand white rabbits (n = 12) were injected with, ultrasonography localization, 0.150 ml of collagenase into the Achilles tendon. The collagenase-induced Achilles tendinopathy (3 weeks) was treated with percutaneous ultrasonic debridement. The tendons were harvested, at 3 weeks after treatment, and were subjected to histological assessment (modified Movin score) and biochemical analysis (collagen isoform content).

Results

Histopathological examination revealed that all tendons injected with collagenase showed areas of hypercellularity and focal areas of tendon disorganization and degeneration. The treated tendons had lower (improved) histopathological scores than injured tendons (P < 0.001). Western blot analysis showed that ultrasonic therapy restored, within statistical limits, collagen type I, III, and X expressions in a treated tendon, to qualitative and semi-quantitative levels of a normal tendon.

Conclusions

We were successfully able to create a collagenase-injected tendinopathy lesion in a rabbit Achilles tendon and visualize the lesion with an ultrasound probe. A 19-gauge ultrasonic probe was inserted into the tendinopathic lesion under direct ultrasound guidance, and minimal tendinopathic debris remained after treatment. The treated tendon demonstrated a normalized qualitative and semi-quantitative collagen profile and improved histological appearance in the short term. This technique demonstrates scientific merit with respect to the minimally invasive treatment of tendinopathy and warrants further studies.

Clinical relevance

Recalcitrant tendinopathy has evaded consistent non-operative treatment since the tendinopathic debris remains in situ, to some extent, with non-operative approaches. This percutaneous emulsification/evacuation approach, under direct ultrasound visualization, has the potential to cure recalcitrant tendinopathies without open surgery, which would benefit the patient and result in significant healthcare cost reductions.

Prognostic factors of extracorporeal shock wave therapy for tendinopathies

INTRODUCTION

Extracorporeal shock wave therapy is very widely used for the management of tendinopathies and plantar fasciitis.

AIM

The aim of the study is to determine whether there are prognostic factors that may influence the outcome of extracorporeal shock wave therapy for these diseases.

METHODS

Three hundred fifty-five patients were analyzed 2 months after shock wave treatment for rotator cuff tendinitis, epicondylitis, Achilles tendinopathy, trocanteritis, jumper's knee or plantar fasciitis. We recorded the epidemiological, clinical and treatment protocol, and these data were correlated with treatment outcome.

RESULTS

Clinical improvement was achieved in 45.9 % of these patients. We discovered that laterality different to the dominant limb (p < 0.0001) and repeated shock wave treatments (p = 0.004) are prognostic factors in an unsuccessful therapy, while being male (p = 0.015) and a high body mass index (p = 0.004) are factors for success. We found no differences in relation to age, diet, blood type, work or sport activity, presence of co-morbidities, drugs, type of tendinopathy, density of energy delivered and other physiotherapy treatment. Knowledge of these prognostic factors may lead to improved insight for physicians and physiotherapists to predict the extent of the recovery and adjust rehabilitation and patient expectations accordingly.

Effect of extracorporeal shock wave treatment on deep partial-thickness burn injury in rats: a pilot study

Extracorporeal shock wave therapy (ESWT) enhances tissue vascularization and neoangiogenesis. Recent animal studies showed improved soft tissue regeneration using ESWT. In most cases, deep partial-thickness burns require skin grafting; the outcome is often unsatisfactory in function and aesthetic appearance. The aim of this study was to demonstrate the effect of ESWT on skin regeneration after deep partial-thickness burns. Under general anesthesia, two standardized deep partial-thickness burns were induced on the back of 30 male Wistar rats. Immediately after the burn, ESWT was given to rats of group 1 (N = 15), but not to group 2 (N = 15). On days 5, 10, and 15, five rats of each group were analyzed. Reepithelialization rate was defined, perfusion units were measured, and histological analysis was performed. Digital photography was used for visual documentation. A wound score system was used. ESWT enhanced the percentage of wound closure in group 1 as compared to group 2 (P < 0.05). The reepithelialization rate was improved significantly on day 15 (P < 0.05). The wound score showed a significant increase in the ESWT group. ESWT improves skin regeneration of deep partial-thickness burns in rats. It may be a suitable and cost effective treatment alternative in this type of burn wounds in the future.

Shockwave therapy differentially stimulates endothelial cells: implications on the control of inflammation via toll-Like receptor 3

Shock wave therapy (SWT) reportedly improves ventricular function in ischemic heart failure. Angiogenesis and inflammation modulatory effects were described. However, the mechanism remains largely unknown. We hypothesized that SWT modulates inflammation via toll-like receptor 3 (TLR3) through the release of cytosolic RNA. SWT was applied to human umbilical vein endothelial cells (HUVECs) with 250 impulses, 0.08 mJ/mm(2) and 3 Hz. Gene expression of TLR3, inflammatory genes and signalling molecules was analysed at different time points by real-time polymerase chain reaction. SWT showed activation of HUVECs: enhanced expression of TLR3 and of the transporter protein for nucleic acids cyclophilin B, of pro-inflammatory cytokines cyclophilin A and interleukin-6 and of anti-inflammatory interleukin-10. No changes were found in the expression of vascular endothelial cell adhesion molecule. SWT modulates inflammation via the TLR3 pathway. The interaction between interleukin (IL)-6 and IL-10 in TLR3 stimulation can be schematically seen as a three-phase regulation over time.

Updates in biological therapies for knee injuries: tendons

Tendons are subjected to tendinopathies caused by inflammation, degeneration, and weakening of the tendon, due to overuse and trauma, which may eventually lead to tendon rupture. Recently, there has been increasing interest in biological approaches to augment tissue healing. Tendon healing occurs through a dynamic process with inflammation, cellular proliferation, and tissue remodeling. In this review article, we discuss the more frequently proposed biological therapies for tendon injuries as platelet-rich plasma, mesenchymal stem cells, extracorporeal shockwave, and scaffolds.

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

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

Extracorporeal shockwave enhanced regeneration of fibrocartilage in a delayed tendon-bone insertion repair model

Fibrous tissue is often formed in delayed healing of tendon bone insertion (TBI) instead of fibrocartilage. Extracorporeal shockwave (ESW) provides mechanical cues and upregulates expression of fibrocartilage-related makers and cytokines. We hypothesized that ESW would accelerate fibrocartilage regeneration at the healing interface in a delayed TBI healing model. Partial patellectomy with shielding at the TBI interface was performed on 32 female New Zealand White Rabbits for establishing this delayed TBI healing model. The rabbits were separated into the control and ESW group for evaluations at postoperative week 8 and 12. Shielding was removed at week 4 and a single ESW treatment was applied at week 6. Fibrocartilage regeneration was evaluated histomorphologically and immunohistochemically. Vickers hardness of the TBI matrix was measured by micro-indentation. ESW group showed higher fibrocartilage area, thickness, and proteoglycan deposition than the control in week 8 and 12. ESW increased expression of SOX9 and collagen II significantly in week 8 and 12, respectively. ESW group showed a gradual transition of hardness from bone to fibrocartilage to tendon, and had a higher Vickers hardness than the control group at week 12. In conclusion, ESW enhanced fibrocartilage regeneration at the healing interface in a delayed TBI healing model.

Uphill running does not exacerbate collagenase-induced pathological changes in the Achilles tendon of rats selectively bred for high-capacity running

The Achilles tendon is a frequent site for degeneration, and advanced understanding of this pathology requires an animal model that replicates the human condition. The aim of this study was to explore whether intratendinous collagenase injection combined with treadmill running created a pathology in the rat Achilles tendon consistent with human Achilles tendinosis. Collagenase was injected into one Achilles tendon of 88 high-capacity running (HCR) rats, which were randomized into treadmill running and cage control groups. Running animals ran at speeds up to 30 m/min on a treadmill at a 15° incline for up to 1 h/d, 5 d/week for 4 or 10 weeks. Cage control animals maintained cage activity. Collagenase induced molecular, histopathological and mechanical changes within the Achilles tendon at 4 weeks. The mechanical changes persisted at 10 weeks; however, the histopathological and majority of the molecular changes were no longer present at 10 weeks. Treadmill running had minimal effect and did not exacerbate the collagenase-induced changes as there were no statistical interactions between the interventions. These data suggest combined intratendinous collagenase injection and treadmill running does not create pathology within the Achilles tendon of rats selectively bred for HCR that is consistent with human Achilles tendinosis.

Relationship between tendon stiffness and failure: a metaanalysis

Tendon is a highly specialized, hierarchical tissue designed to transfer forces from muscle to bone; complex viscoelastic and anisotropic behaviors have been extensively characterized for specific subsets of tendons. Reported mechanical data consistently show a pseudoelastic, stress-vs.-strain behavior with a linear slope after an initial toe region. Many studies report a linear, elastic modulus, or Young's modulus (hereafter called elastic modulus) and ultimate stress for their tendon specimens. Individually, these studies are unable to provide a broader, interstudy understanding of tendon mechanical behavior. Herein we present a metaanalysis of pooled mechanical data from a representative sample of tendons from different species. These data include healthy tendons and those altered by injury and healing, genetic modification, allograft preparation, mechanical environment, and age. Fifty studies were selected and analyzed. Despite a wide range of mechanical properties between and within species, elastic modulus and ultimate stress are highly correlated (R(2) = 0.785), suggesting that tendon failure is highly strain-dependent. Furthermore, this relationship was observed to be predictable over controlled ranges of elastic moduli, as would be typical of any individual species. With the knowledge gained through this metaanalysis, noninvasive tools could measure elastic modulus in vivo and reasonably predict ultimate stress (or structural compromise) for diseased or injured tendon.

Surgical advances in burn and reconstructive plastic surgery: new and emerging technologies

This article introduces and discusses several biophysical and cellular modalities that are being tested or used in clinical practice to optimize wound bed preparation, effect soft tissue coverage, and improve the quality of the inevitable and resultant scar. Among these promising technologies is the use of electrical stimulation to mimic a physiologic current of injury in an effort to accelerate re-epithelialization and the wound healing process. Over the past several years an on-site individualized regenerative medicine kit has become commercially available (ReCell, Avita Medical), utilizing well-established laboratory techniques of cell separation without the need for cell cultivation in an effort to expand and promote wound coverage and end result.

Dose-response effect of an intra-tendon application of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) in a rat Achilles tendinopathy model

The purpose of this study was to assess whether intra-tendon delivery of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) would improve Achilles tendon repair in a rat collagenase-induced tendinopathy model. Seven days following collagenase induction of tendinopathy, one of four intra-tendinous treatments was administered: (i) Vehicle control (sodium acetate buffer), (ii) 1.02 µg rhPDGF-BB, (iii) 10.2 µg rhPDGF-BB, or (iv) 102 µg rhPDGF-BB. Treated tendons were assessed for histopathological (e.g., proliferation, tendon thickness, collagen fiber density/orientation) and biomechanical (e.g., maximum load-to-failure and stiffness) outcomes. By 7 days post-treatment, there was a significant increase in cell proliferation with the 10.2 and 102 µg rhPDGF-BB-treated groups (p=0.049 and 0.015, respectively) and in thickness at the tendon midsubstance in the 10.2 µg of rhPDGF-BB group (p=0.005), compared to controls. All groups had equivalent outcomes by Day 21. There was a dose-dependent effect on the maximum load-to-failure, with no significant difference in the 1.02 and 102 µg rhPDGF-BB doses but the 10.2 µg rhPDGF-BB group had a significant increase in load-to-failure at 7 (p=0.003) and 21 days (p=0.019) compared to controls. The rhPDGF-BB treatment resulted in a dose-dependent, transient increase in cell proliferation and sustained improvement in biomechanical properties in a rat Achilles tendinopathy model, demonstrating the potential of rhPDGF-BB treatment in a tendinopathy application. Consequently, in this model, data suggest that rhPDGF-BB treatment is an effective therapy and thus, may be an option for clinical applications to treat tendinopathy.

The long-term effects of extracorporeal shock waves on the epiphysis of the adolescent rat

BACKGROUND

Extracorporeal shock waves (ESW) have been successfully used to treat musculoskeletal injuries, tendinopathy, and plantar fasciitis. Different side effects of high-energy ESWT on bones, tendons, nerves, epiphysis, and cartilage have been discussed. Although the effects of ESW on the epiphysis in animal models have been described, no studies have investigated the long-term effect of ESW on the immature epiphysis in an animal model. The purpose of this study was to investigate the long-term effects of ESW on the immature epiphysis in rats.

METHODS

Sixteen 4-week old Wistar albino rats, average weight 116.3 grams (109.6-120.2 g) were used for these experiments. The rats were randomly divided into two groups, the ESW 1500 pulses (ESW1500p) group (n = 8) and the ESW 3000 pulses (ESW3000p) group (n = 8). In the ESW1500p group, 1500 pulses, at 4 bar, of 1-Hz shockwaves were applied, once, to the left knees of the rats. In the ESW3000p group, 3000 pulses, at 4 bar, of 1-Hz shockwaves were applied, once, to the left knees of the rats. The right knees (n = 16) of the rats in the two groups were used as the controls. The animals were sacrificed after an 8-month follow-up period. Femoral epiphyses were assessed by use of histology. The femoral length (FL), tibial length (TL), and femoral supracondylar medio-lateral width (MLW) were measured.

RESULTS

There was no statistically significant difference between FL, TL, and MLW for the three groups (P > 0.05). The average histological scores were 8.8 (7-10), 17.8 (15-22), and 2.7 (0-4) in the ESW1500p, the ESW3000p groups, and the controls, respectively. The average histological score for the ESW3000p group was significantly higher than those for the ESW1500p group and the controls (P < 0.001). The average histological score for the ESW1500p group was significantly higher than that for the controls (P < 0.001).

CONCLUSIONS

The histological findings of this study indicate that ESW increased the cellularity and basophilia of the extracellular matrix (ECM) in the adolescent rat epiphysis and there were no negative effects on extremity measurements in the long term.

Extracorporeal shock wave therapy is not useful after arthroscopic rotator cuff repair

PURPOSE

Extracorporeal shock wave therapy (ESWT) is known to accelerate the healing of musculoskeletal tissue. The purpose of this study was to test the hypothesis that ESWT stimulates rotator cuff healing after arthroscopic repair.

METHODS

Seventy-one consecutive patients with a small- to large-sized rotator cuff tear underwent arthroscopic rotator cuff repair. The patients were randomized into two groups: 35 patients underwent ESWT at 6 weeks after surgery (ESWT group) and 36 patients did not (control group). Cuff integrity was evaluated with computed tomographic arthrography at 6 months after surgery. Constant and UCLA scores were measurable outcomes.

RESULTS

All patients were available for a minimum one-year follow-up. The mean age of the ESWT and control groups was 59.4 (SD: 7.7) and 58.6 years (SD: 7.8) (n.s.). There were no significant differences in tear size and repair method between the two groups (n.s.). The mean Constant and UCLA scores, respectively, increased from 54.6 to 90.6 (P < 0.001) and from 18.5 to 27.4 (P < 0.001) in the ESWT group, and from 58.9 to 89.3 (P < 0.001) and 18.5 to 27.4 in the control group. Computed tomographic arthrography was performed in 26 patients from the ESWT group and 24 from the control group, and cuff integrity was maintained in 46 out of 50 patients. Definite re-tear was observed in two patients of the ESWT group and four of the controls. There were no complications associated with ESWT.

CONCLUSION

This study failed to prove that ESWT stimulates rotator cuff healing after arthroscopic rotator cuff repair. Additional ESWT after rotator cuff repair could theoretically be advantageous, and it was proven to be safe in this study.

LEVEL OF EVIDENCE

II.