Chronic tendinopathy tissue pathology, pain mechanisms, and etiology with a special focus on inflammation

Tendon and ligament mechanical loading in the pathogenesis of inflammatory arthritis

Mechanical loading is an important factor in musculoskeletal health and disease. Tendons and ligaments require physiological levels of mechanical loading to develop and maintain their tissue architecture, a process that is achieved at the cellular level through mechanotransduction-mediated fine tuning of the extracellular matrix by tendon and ligament stromal cells. Pathological levels of force represent a biological (mechanical) stress that elicits an immune system-mediated tissue repair pathway in tendons and ligaments. The biomechanics and mechanobiology of tendons and ligaments form the basis for understanding how such tissues sense and respond to mechanical force, and the anatomical extent of several mechanical stress-related disorders in tendons and ligaments overlaps with that of chronic inflammatory arthritis in joints. The role of mechanical stress in 'overuse' injuries, such as tendinopathy, has long been known, but mechanical stress is now also emerging as a possible trigger for some forms of chronic inflammatory arthritis, including spondyloarthritis and rheumatoid arthritis. Thus, seemingly diverse diseases of the musculoskeletal system might have similar mechanisms of immunopathogenesis owing to conserved responses to mechanical stress.

Do joint mobilizations assist in the recovery of lateral elbow tendinopathy? A systematic review and meta-analysis

STUDY DESIGN

Systematic review.

INTRODUCTION

No consensus exists as to which are the most effective methods to treat the symptoms associated with lateral elbow tendinopathy (LET). Research has suggested that joint mobilizations may assist in the recovery of patients with LET.

PURPOSE OF THE STUDY

To determine if joint mobilizations are effective in improving pain, grip strength, and disability in adults with LET.

METHODS

Searches in 3 databases were performed to identify relevant clinical trials. Reviewers independently extracted data and assessed the methodological quality. Summary measures of quantitative data were extracted or calculated where possible. Appropriate data were pooled for meta-analysis using a random-effects model.

RESULTS

A total of 20 studies met the inclusion criteria; 7 were included in the meta-analysis. Studies were broadly classified into 3 groups: mobilization with movement (MWM), Mill's manipulation, and regional mobilization techniques. Pooled data across all time periods demonstrated a mean effect size of 0.43 (95% confidence interval [CI]: 0.15-0.71) for MWM on improving pain rating, and 0.31 (95% CI: 0.11-0.51) for MWM on improving grip strength, 0.47 (95% CI: 0.11-0.82) for Mill's manipulation on improving pain rating. A mean effect size of -0.01 (95% CI: -0.27 to -0.26) shows Mill's manipulation did not improve pain free grip strength. Functional outcomes varied considerably among studies. Pain, grip strength, and functional outcomes were improved with regional mobilizations.

CONCLUSION

There is compelling evidence that joint mobilizations have a positive effect on both pain and/or functional grip scores across all time frames compared to control groups in the management of LET.

Triceps Surae Muscle Architecture Adaptations to Eccentric Training

Background

Eccentric exercises have been used in physical training, injury prevention, and rehabilitation programs. The systematic use of eccentric training promotes specific morphological adaptations on skeletal muscles. However, synergistic muscles, such as the triceps surae components, might display different structural adaptations due to differences in architecture, function, and load sharing. Therefore, the purpose of this study was to determine the effects of an eccentric training program on the triceps surae (GM, gastrocnemius medialis; GL, gastrocnemius lateralis; and SO, soleus) muscle architecture.

Methods

Twenty healthy male subjects (26 ± 4 years) underwent a 4-week control period followed by a 12-week eccentric training program. Muscle architecture [fascicle length (FL), pennation angle (PA), and muscle thickness (MT)] of GM, GL, and SO was evaluated every 4 weeks by ultrasonography.

Results

Fascicle lengths (GM: 13.2%; GL: 8.8%; SO: 21%) and MT (GM: 14.9%; GL: 15.3%; SO: 19.1%) increased from pre- to post-training, whereas PAs remained similar. GM and SO FL and MT increased up to the 8th training week, whereas GL FL increased up to the 4th week. SO displayed the highest, and GL the smallest gains in FL post-training.

Conclusion

All three synergistic plantar flexor muscles increased FL and MT with eccentric training. MT increased similarly among the synergistic muscles, while the muscle with the shortest FL at baseline (SO) showed the greatest increase in FL.

Multi-Scale Loading and Damage Mechanisms of Plantaris and Rat Tail Tendons

Tendinopathy, degeneration of the tendon that leads to pain and dysfunction, is common in both sports and occupational settings, but multi-scale mechanisms for tendinopathy are still unknown. We recently showed that micro-scale sliding (shear) is responsible for both load transfer and damage mechanisms in the rat tail tendon; however, the rat tail tendon is a specialized non-load-bearing tendon, and thus the load transfer and damage mechanisms are still unknown for load-bearing tendons. The objective of this study was to investigate the load transfer and damage mechanisms of load-bearing tendons using the rat plantaris tendon. We demonstrated that micro-scale sliding is a key component for both mechanisms in the plantaris tendon, similar to the tail tendon. Namely, the micro-scale sliding was correlated with applied strain, demonstrating that load was transferred via micro-scale sliding in the plantaris and tail tendons. In addition, while the micro-scale strain fully recovered, the micro-scale sliding was non-recoverable and strain-dependent, and correlated with tissue-scale mechanical parameters. When the applied strain was normalized, the % magnitudes of non-recoverable sliding was similar between the plantaris and tail tendons. Statement of clinical significance: Understanding the mechanisms responsible for the pathogenesis and progression of tendinopathy can improve prevention and rehabilitation strategies and guide therapies and the design of engineered constructs. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1827-1837, 2019.

Photobiomodulation of Matrix Metalloproteinases in Rat Calcaneal Tendons

Objective: The main objective was to verify the modulatory effects of MMP-1, MMP-3, and MMP-13 levels on the partially injured calcaneal tendons of rat exposure to photobiomodulation. Background: Photobiomodulation has been shown to have anti-inflammatory and regenerative effects on tendon injuries. However, there is still uncertainty regarding the beneficial effects in matrix metalloproteinase (MMP) levels, especially MMP-1, -3, and -13. Materials and methods: Sixty-five male Wistar rats were used. Sixty were submitted to a direct trauma on the calcaneal tendons and were randomly distributed into the following six groups: LASER 1, 3, and 7 (10 partially injured calcaneal tendons in each group treated with photobiomodulation for 1, 3, and 7 days, respectively) and Sham 1, 3, and 7 (same injury, with simulated photobiomodulation). The remaining five animals were allocated to the normal group (no injury or treatment procedure). The 780 nm low-level laser was applied with 70 mW of mean power and 17.5 J/cm² of fluency for 10 sec, once a day. The tendons were surgically removed and analyzed for MMP-1, MMP-3, and MMP-13 through immunohistochemistry. Results: MMP-3 levels remained close to normal in all experimental groups (p > 0.05); however, reductions (p < 0.05) in MMP-1 and MMP-13 levels were detected in the groups submitted to one, three, and seven low level laser therapy applications. Conclusions: The photobiomodulation protocol was able to reduce MMP-1 and MMP-13 levels in injured calcaneal tendons.

Curcumin in tissue engineering: A traditional remedy for modern medicine

Curcumin is the principal polyphenolic compound present in turmeric with broad applications in tissue engineering and regenerative medicine. It has some important inherent properties with the potential to facilitate tissue healing, including anti-inflammatory, anti-oxidant, and antibacterial activities. Therefore, curcumin has been used for the treatment of various damaged tissues, especially wound injuries. There are different forms of curcumin, among which nano-formulations are of a great importance in regenerative medicine. It is also important to design sophisticated delivery systems for controlled/localized delivery of curcumin to the target tissues and organs. Although there are many reports on the advantages of this compound, further research is required to fully explore its clinical usage. The review describes the physicochemical and biological properties of curcumin and the current state of the evidence on its applications in tissue engineering. © 2018 BioFactors, 45(2):135-151, 2019.

First clinical experience with a new injectable recombinant human collagen scaffold combined with autologous platelet-rich plasma for the treatment of lateral epicondylar tendinopathy (tennis elbow)

BACKGROUND

Lateral epicondylitis is a tendinopathy of the common extensor origin at the elbow. When traditional conservative treatment fails, more effective therapies are needed. Vergenix Soft Tissue Repair (STR) Matrix (CollPlant Ltd., Ness-Ziona, Israel) is an injectable gel composed of cross-linked bioengineered recombinant human type I collagen combined with autologous platelet-rich plasma (STR/PRP). The complex forms a collagen-fibrin matrix that promotes cell migration and tissue repair. Based on positive outcomes from preclinical trials, this study is the first clinical trial of STR/PRP on tendinopathy. We hypothesized that STR/PRP would be a safe and effective treatment for lateral epicondylar tendinopathy.

METHODS

Patients with chronic lateral epicondylitis underwent treatment with STR/PRP. Outcome assessment included grip strength, functional disability, and changes in sonographic tendon appearance for up to 6 months after treatment.

RESULTS

The study enrolled 40 patients. No systemic or local severe adverse events were reported. Clinical evaluation revealed an improvement in the mean Patient-Rated Tennis Elbow Evaluation score from 64.8 before treatment and showed a 59% reduction at 6 months. The 12-Item Short-Form Health Survey questionnaire showed improvement from a mean score of 30.7 to 37.7 at the final follow-up. Grip strength increased from 28.8 kg at baseline to 36.8 kg at 6 months. Improvements in sonographic tendon appearance were evident among 68% of patients.

CONCLUSION

STR/PRP is a safe treatment that effectively induces clinically significant improvements in elbow symptoms and general well-being as well as objective measures of strength and imaging of the common extensor tendon within 6 months of treatment of elbow tendinopathy recalcitrant to standard treatments.

Correlation Between IL-20 and De Quervain's Disease Severity

De Quervain's disease is a stenosing tenosynovitis of the first dorsal compartment of the wrist. Histopathological studies have reported that the thickening of the first dorsal retinaculum is characterized by degeneration rather than inflammation. However, significant infiltration of mast cells and macrophages was noted in a torn tendon study, which suggested that innate immune pathways are part of the mechanism that mediates early tendinopathy. Recently, Interleukin-20 (IL-20) has been reported to provoke potent inflammation and regulate angiogenesis and chemotaxis, which are important for the pathogenesis of inflammatory diseases. The main purpose of our study was to investigate the correlation between IL-20 and tumor necrosis factor (TNF-α) and clarify the potential predictor of tendinopathy progression. Hematoxylin and eosin (H & E) and immunohistochemistry (IHC) staining were used to score and analyze the clinical outcome. TNF-α, IL-20 and related inflammation cytokines were examined. Moreover, the tenocytes were cultured with a stimulator and were used to examine inflammatory cytokine secretions. A real-time polymerase chain reaction (Real-time PCR) was used to detect the gene expression profile. The IHC data showed that TNF-α is up-regulated in grade III de Quervain's. The analysis data showed that IL-20 is positively correlated with TNF-α and disease severity. The real-time PCR showed that the inflammation stimulator enhanced the expression of IL-20 mRNA expression. Inflammation cytokines such as TNF-alpha, transforming growth factor-β (TGF-β) and IL-1 have been used as predictors of de Quervain's; IL-20 is a new predictor based on this study. In the future, IL-20 expression's involvement in the molecular mechanism of the severity of de Quervain's should be further investigated.

Comparison of the sonographic features of the Achilles Tendon complex in patients with and without achilles tendinopathy: A case-control study

AIM

The aim of the present study was to evaluate and quantify with ultrasound imaging (USI) the Achilles tendon thickness, cross-sectional area (CSA), Kager's fat pad length and gastrocnemius-soleus pennation angle (PA) between chronic mid-portion Achilles tendinopathy (AT) and healthy subjects.

METHODS

A total sample of 143 individuals (age: 41.3 ± 12.0 y; height: 1.74 ± 0.0 m; weight: 75.0 ± 11.4 kg; body mass index, BMI: 24.4 ± 2.6 kg/m²) was recruited and divided in two groups: chronic mid-portion AT group (n = 71) and a healthy group (n = 72).

RESULTS

The thickness and CSA at 4 cm and 6 cm from the calcaneus was increased showing statistically significant differences (P < .01) in favor the tendinopathy group. For the gastrocnemius-soleus PA and Kager's fat pad length, significant differences (P < .01) were observed for a decrease in favor of the tendinopathy group.

CONCLUSIONS

This study reported an increase of Achilles tendon thickness and CSA at 4 cm and 6 cm from the calcaneus as well as a decrease in gastrocnemius-soleus PA and Kager's fat pad length in patients with chronic mid-portion AT.

The Effect of Impactful Articles on Clinical Practice in the United States: Corticosteroid Injection for Patients with Lateral Epicondylitis

BACKGROUND

Following publication of high-level evidence demonstrating that it is not an effective treatment for lateral epicondylitis, a reduction in the corticosteroid injection rate would be expected. The authors aimed to clarify current clinical practice pattern for lateral epicondylitis and identify factors that influence the introduction of evidence into clinical practice.

METHODS

In this administrative claims analysis, the authors used 2009 to 2015 Truven MarketScan data to extract claims for corticosteroid injection, physical therapy, platelet-rich plasma injection, and surgery for lateral epicondylitis. The authors performed multivariable analysis using a generalized estimating equation model to identify the variables that potentially affect the odds of receiving a given treatment.

RESULTS

Among 711,726 claims, the authors found that the odds of receiving a corticosteroid injection increased slightly after publication of contradictory evidence (OR, 1.7; 95 percent CI, 1.04 to 1.11 in 2015). Being male (OR, 1.21; 95 percent CI, 1.19 to 1.23), older (OR, 1.16; 95 percent CI, 1.13 to 1.19), and having managed care insurance (OR, 1.15; 95 percent CI, 1.13 to 1.18) significantly contributed to increased odds of receiving corticosteroid injections. Patients seen at facilities in the South (OR, 1.33; 95 percent CI, 1.30 to 1.36 compared with the Northeast) and by plastic/orthopedic surgeons (OR, 2.48; 95 percent CI, 2.43 to 2.52) also had increased odds of receiving corticosteroid injection.

CONCLUSIONS

Corticosteroid injection use did not decrease after publication of impactful articles, regardless of provider specialty or other patient-related factors. This finding emphasizes that there are various barriers for even high-level evidence to overcome the inertia of current practice.

Differing MRI appearances of symptomatic proximal hamstring tendinopathy with ageing: a comparison of appearances in patients below and above 45 years

AIM

To compare magnetic resonance imaging (MRI) appearances of symptomatic proximal hamstring tendinopathy (PHT) in younger (<45 years) and older (>45 years) patients.

MATERIALS AND METHODS

MRI of patients with symptomatic PHT were reviewed and compared to asymptomatic age- and sex-matched controls. Appearances recorded were as: type 0, normal tendon; type I, intra-substance signal abnormality; type II, ischial bone and soft-tissue oedema with/without type I findings; type III, curvilinear fluid signal tearing with/without type II findings; type IV, bony avulsion. Disease pattern was compared between age groups using Fisher's exact test.

RESULTS

Thirty-one symptomatic patients (18 male, 13 female; mean age 42 years) were identified. Imaging findings of 16 patients >45 years, 15 patients <45 were as follows: type 0 n=8, type I n=7, type II n=6, type III n=10, type IV n=0. Those >45 years tended to have type III tendinopathy, no examples of type III disease were found in patients <45 years (p<0.001). No significant difference in disease pattern was seen between males and females (p=0.39). Seven of 31 controls >45 years had type III findings and four controls <45 years had type I findings.

CONCLUSION

MRI appearances of symptomatic PHT differ with age. Differences may reflect mechanism, whereby overuse-related micro-tearing of healthy tendons occurs in young patients versus degenerative tendinopathy in older patients. Abnormal tendon appearances in patients >45 years may or may not be symptomatic. In contrast, abnormalities identified in younger patients are generally symptomatic. These described differences are important in the primary diagnosis and may impact upon patient response to therapy.

Refractory patellar tendinopathy treated by arthroscopic decortication of the inferior patellar pole in athletes: Mid-term outcomes

BACKGROUND

This study aimed to evaluate the clinical outcomes of arthroscopic decortication of the inferior patellar pole in athletes with refractory chronic patellar tendinopathy.

METHODS

Thirty-seven athletes in whom conservative management for at least six months failed underwent arthroscopic patellar tendon debridement and decortication of the inferior pole of the patella. Clinical outcomes were evaluated using subjective knee scores and isokinetic muscle strength tests. The average duration taken and sports participation level were also assessed.

RESULTS

The mean follow-up period was 51.3 ± 14.8 months. At the last follow-up, all improvements in subjective knee scores including Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Victorian Institute of Sport Assessment -Patella (VISA-P) score, and Kujala score were statistically significant (p<.001). Tegner activity scale improved from 6.5±1.0 to 8.9±0.8 (p<.001). Limb symmetry index for extensor peak torque improved from 71.4±19.6% to 92.7±21.7% (p<.001). Thirty-two (86.5 %) athletes were able to return to full sports activities in a mean 3.5±1.7months, and 27 (73%) athletes maintained their previous sports activity level at the last follow-up. Symptoms recurred in two (5.2%).

CONCLUSIONS

Arthroscopic decortication of the inferior pole of the patella showed satisfactory clinical results and high rates of return to sports at mid-term follow-up in professional athletes with refractory chronic patellar tendinopathy. This technique could be an invasive, safe, and effective treatment for chronic patellar tendinopathy in professional athletes who want a faster return to sports.

LEVEL OF EVIDENCE

Level IV, case series.

Substrate fiber alignment mediates tendon cell response to inflammatory signaling

Healthy tendon tissue features a highly aligned extracellular matrix that becomes disorganized with disease. Recent evidence suggests that inflammation coexists with early degenerative changes in tendon, and that crosstalk between immune-cells and tendon fibroblasts (TFs) can contribute to poor tissue healing. We hypothesized that a disorganized tissue architecture may predispose tendon cells to degenerative extracellular matrix remodeling pathways, particularly within a pro-inflammatory niche. This hypothesis was tested by analyzing human TFs cultured on electrospun polycaprolactone (PCL) mats with either highly aligned or randomly oriented fiber structures. We confirmed that fibroblast morphology, phenotype, and markers of matrix turnover could be significantly affected by matrix topography. More strikingly, the TF response to paracrine signals from polarized macrophages or by stimulation with pro-inflammatory cytokines featured significant downregulation of signaling related to extracellular synthesis, with significant concomitant upregulation of gene and protein expression of matrix degrading enzymes. Critically, this tendency towards degenerative re-regulation was exacerbated on randomly oriented PCL substrates. These novel findings indicate that highly aligned tendon cell scaffolds not only promote tendon matrix synthesis, but also play a previously unappreciated role in mitigating adverse resident fibroblast response within an inflammatory milieu.

STATEMENT OF SIGNIFICANCE

Use of biomaterial scaffolds for tendon repair often results in tissue formation characteristic of scar tissue, rather than the highly aligned type-1 collagen matrix of healthy tendons. We hypothesized that non-optimal biomaterial surfaces may play a role in these outcomes, specifically randomly oriented biomaterial surfaces that unintentionally mimic structure of pathological tendon. We observed that disorganized scaffold surfaces do adversely affect early cell attachment and gene expression. We further identified that disorganized fiber surfaces can prime tendon cells toward pro-inflammatory signaling. These findings represent provocative evidence unstructured fiber surfaces may underlie inflammatory responses that drive aberrant collagen matrix turnover. This work could be highly relevant for the design of cell instructive biomaterial therapies that yield positive clinical outcomes.

Exploring the In Vivo Anti-Inflammatory Actions of Simvastatin-Loaded Porous Microspheres on Inflamed Tenocytes in a Collagenase-Induced Animal Model of Achilles Tendinitis

Tendon rupture induces an inflammatory response characterized by release of pro-inflammatory cytokines and impaired tendon performance. This study sought to investigate the therapeutic effects of simvastatin-loaded porous microspheres (SIM/PMSs) on inflamed tenocytes in vitro and collagenase-induced Achilles tendinitis in vivo. The treatment of SIM/PMSs in lipopolysaccharide (LPS)-treated tenocytes reduced the mRNA expressions of pro-inflammatory cytokines (Matrix metalloproteinase-3 (MMP-3), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)). In addition, the local injection of SIM/PMSs into the tendons of collagenase-induced Achilles tendinitis rat models suppressed pro-inflammatory cytokines (MMP-3, COX-2, IL-6, TNF-α, and MMP-13). This local treatment also upregulated anti-inflammatory cytokines (IL-4, IL-10, and IL-13). Furthermore, treatment with SIM/PMSs also improved the alignment of collagen fibrils and effectively prevented collagen disruption in a dose-dependent manner. Therefore, SIM/PMSs treatment resulted in an incremental increase in the collagen content, stiffness, and tensile strength in tendons. This study suggests that SIM/PMSs have great potential for tendon healing and restoration in Achilles tendinitis.

Different Achilles Tendon Pathologies Show Distinct Histological and Molecular Characteristics

Reasons for the development of chronic tendon pathologies are still under debate and more basic knowledge is needed about the different diseases. The aim of the present study was therefore to characterize different acute and chronic Achilles tendon disorders. Achilles tendon samples from patients with chronic tendinopathy (n = 7), chronic ruptures (n = 6), acute ruptures (n = 13), and intact tendons (n = 4) were analyzed. The histological score investigating pathological changes was significantly increased in tendinopathy and chronic ruptures compared to acute ruptures. Inflammatory infiltration was detected by immunohistochemistry in all tendon pathology groups, but was significantly lower in tendinopathy compared to chronic ruptures. Quantitative real-time PCR (qRT-PCR) analysis revealed significantly altered expression of genes related to collagens and matrix modeling/remodeling (matrix metalloproteinases, tissue inhibitors of metalloproteinases) in tendinopathy and chronic ruptures compared to intact tendons and/or acute ruptures. In all three tendon pathology groups markers of inflammation (interleukin (IL) 1β, tumor necrosis factor α, IL6, IL10, IL33, soluble ST2, transforming growth factor β1, cyclooxygenase 2), inflammatory cells (cluster of differentaition (CD) 3, CD68, CD80, CD206), fat metabolism (fatty acid binding protein 4, peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, adiponectin), and innervation (protein gene product 9.5, growth associated protein 43, macrophage migration inhibitory factor) were detectable, but only in acute ruptures significantly regulated compared to intact tendons. The study gives an insight into structural and molecular changes of pathological processes in tendons and might be used to identify targets for future therapy of tendon pathologies.

THE REHABILITATION OF A RUNNER WITH ILIOPSOAS TENDINOPATHY USING AN ECCENTRIC-BIASED EXERCISE-A CASE REPORT

Background and Purpose

While there is much discussion about tendinopathy in the literature, there is little reference to the less common condition of iliopsoas tendinopathy, and no documentation of the condition in runners. The iliopsoas is a major decelerator of the hip and eccentric loading of the iliopsoas is an important component of energy transfer during running. Eccentric training is a thoroughly researched method of treating tendinopathy but has shown mixed results. The purpose of this case report is to describe the rehabilitation of a runner with iliopsoas tendinopathy, and demonstrate in a creative eccentric-biased technique to assist with treatment. A secondary objective is to illustrate how evidence on intervention for other tendinopathies was used to guide rehabilitation of this seldom described condition.

Case Description

The subject was a 39-year-old female middle distance runner diagnosed with iliopsoas tendinopathy via ultrasound, after sudden onset of left anterior groin pain. Symptoms began after a significant increase in running load, and persisted, despite rest, for three months. The intervention consisted of an eccentric-biased hip flexor exercise, with supportive kinetic chain exercises and progressive loading in a return to running program.

Outcomes

The Copenhagen Hip and Groin Outcome Score, the Visual Analogue Scale, the Global Rating of Change Scale and manual muscle testing scores all improved after 12 weeks of intervention with further improvement at the five-year follow up. After 12 weeks of intervention, the subject was running without restriction and had returned to her pre-injury running mileage at the five-year follow up.

Discussion

The eccentric-biased exercise in conjunction with exercises addressing the kinetic chain and a progressive tendon loading program, were successful in the rehabilitation of this subject with iliopsoas tendinopathy. This case report is the first to provide a description on the rehabilitation of iliopsoas tendinopathy, and offers clinicians suggestions and guidance for treatment and exercise choice in the clinical environment.

Level of Evidence

5.

Imbalances in the Development of Muscle and Tendon as Risk Factor for Tendinopathies in Youth Athletes: A Review of Current Evidence and Concepts of Prevention

Tendons feature the crucial role to transmit the forces exerted by the muscles to the skeleton. Thus, an increase of the force generating capacity of a muscle needs to go in line with a corresponding modulation of the mechanical properties of the associated tendon to avoid potential harm to the integrity of the tendinous tissue. However, as summarized in the present narrative review, muscle and tendon differ with regard to both the time course of adaptation to mechanical loading as well as the responsiveness to certain types of mechanical stimulation. Plyometric loading, for example, seems to be a more potent stimulus for muscle compared to tendon adaptation. In growing athletes, the increased levels of circulating sex hormones might additionally augment an imbalanced development of muscle strength and tendon mechanical properties, which could potentially relate to the increasing incidence of tendon overload injuries that has been indicated for adolescence. In fact, increased tendon stress and strain due to a non-uniform musculotendinous development has been observed recently in adolescent volleyball athletes, a high-risk group for tendinopathy. These findings highlight the importance to deepen the current understanding of the interaction of loading and maturation and demonstrate the need for the development of preventive strategies. Therefore, this review concludes with an evidence-based concept for a specific loading program for increasing tendon stiffness, which could be implemented in the training regimen of young athletes at risk for tendinopathy. This program incorporates five sets of four contractions with an intensity of 85–90% of the isometric voluntary maximum and a movement/contraction duration that provides 3 s of high magnitude tendon strain.

Investigating mechanisms of tendon damage by measuring multi-scale recovery following tensile loading

Tendon pathology is associated with damage. While tendon damage is likely initiated by mechanical loading, little is known about the specific etiology. Damage is defined as an irreversible change in the microstructure that alters the macroscopic mechanical parameters. In tendon, the link between mechanical loading and microstructural damage, resulting in macroscopic changes, is not fully elucidated. In addition, tendon damage at the macroscale has been proposed to initiate when tendon is loaded beyond a strain threshold, yet the metrics to define the damage threshold are not determined. We conducted multi-scale mechanical testing to investigate the mechanism of tendon damage by simultaneously quantifying macroscale mechanical and microstructural changes. At the microscale, we observe full recovery of the fibril strain and only partial recovery of the interfibrillar sliding, indicating that the damage initiates at the interfibrillar structures. We show that non-recoverable sliding is a mechanism for tendon damage and is responsible for the macroscale decreased linear modulus and elongated toe-region observed at the fascicle-level, and these macroscale properties are appropriate metrics that reflect tendon damage. We concluded that the inflection point of the stress-strain curve represents the damage threshold and, therefore, may be a useful parameter for future studies. Establishing the mechanism of damage at multiple length scales can improve prevention and rehabilitation strategies for tendon pathology.

STATEMENT OF SIGNIFICANCE

Tendon pathology is associated with mechanically induced damage. Damage, as defined in engineering, is an irreversible change in microstructure that alters the macroscopic mechanical properties. Although microstructural damage and changes to macroscale mechanics are likely, this link to microstructural change was not yet established. We conducted multiscale mechanical testing to investigate the mechanism of tendon damage by simultaneously quantifying macroscale mechanical and microstructural changes. We showed that non-recoverable sliding between collagen fibrils is a mechanism for tendon damage. Establishing the mechanism of damage at multiple length scales can improve prevention and rehabilitation strategies for tendon pathology.

Effect of High-Volume Injection, Platelet-Rich Plasma, and Sham Treatment in Chronic Midportion Achilles Tendinopathy: A Randomized Double-Blinded Prospective Study

BACKGROUND

Injection therapies are often considered alongside exercise for chronic midportion Achilles tendinopathy (AT), although evidence of their efficacy is sparse.

PURPOSE

To determine whether eccentric training in combination with high-volume injection (HVI) or platelet-rich plasma (PRP) injections improves outcomes in AT.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 60 men (age, 18-59 years) with chronic (>3 months) AT were included and followed for 6 months (n = 57). All participants performed eccentric training combined with either (1) one HVI (steroid, saline, and local anesthetic), (2) four PRP injections each 14 days apart, or (3) placebo (a few drops of saline under the skin). Randomization was stratified for age, function, and symptom severity (Victorian Institute of Sports Assessment-Achilles [VISA-A]). Outcomes included function and symptoms (VISA-A), self-reported tendon pain during activity (visual analog pain scale [VAS]), tendon thickness and intratendinous vascularity (ultrasonographic imaging and Doppler signal), and muscle function (heel-rise test). Outcomes were assessed at baseline and at 6, 12, and 24 weeks of follow-up.

RESULTS

VISA-A scores improved in all groups at all time points ( P < .05), with greater improvement in the HVI group (mean ± SEM, 6 weeks = 27 ± 3 points; 12 weeks = 29 ± 4 points) versus PRP (6 weeks = 14 ± 4; 12 weeks = 15 ± 3) and placebo (6 weeks = 10 ± 3; 12 weeks = 11 ± 3) at 6 and 12 weeks ( P < .01) and in the HVI (22 ± 5) and PRP (20 ± 5) groups versus placebo (9 ± 3) at 24 weeks ( P < .01). VAS scores improved in all groups at all time points ( P < .05), with greater decrease in HVI (6 weeks = 49 ± 4 mm; 12 weeks = 45 ± 6 mm; 24 weeks = 34 ± 6 mm) and PRP (6 weeks = 37 ± 7 mm; 12 weeks = 41 ± 7 mm; 24 weeks = 37 ± 6 mm) versus placebo (6 weeks = 23 ± 6 mm; 12 weeks = 30 ± 5 mm; 24 weeks = 18 ± 6 mm) at all time points ( P < .05) and in HVI versus PRP at 6 weeks ( P < .05). Tendon thickness showed a significant decrease only in HVI and PRP groups during the intervention, and this was greater in the HVI versus PRP and placebo groups at 6 and 12 weeks ( P < .05) and in the HVI and PRP groups versus the placebo group at 24 weeks ( P < .05). Muscle function improved in the entire cohort with no difference between the groups.

CONCLUSION

Treatment with HVI or PRP in combination with eccentric training in chronic AT seems more effective in reducing pain, improving activity level, and reducing tendon thickness and intratendinous vascularity than eccentric training alone. HVI may be more effective in improving outcomes of chronic AT than PRP in the short term. Registration: NCT02417987 ( ClinicalTrials.gov identifier).

USG-guided injection of corticosteroid for lateral epicondylitis does not improve clinical outcomes: a prospective randomised study

BACKGROUND

Corticosteroid injection used to be the treatment of choice for lateral epicondylitis. Most injections are performed blindly. In the blinded technique, it could be difficult to determine the exact pathological localisation. The purpose of this single-blinded, randomised controlled clinical study was to compare the clinical therapeutic effects of blinded and USG-guided corticosteroid injection therapy in lateral epicondylitis.

PATIENTS AND METHODS

Forty patients with chronic lateral epicondylitis were included in this clinical trial. The patients were randomly allocated to blinded group or USG-guided injection group according to a computer-generated randomisation list. All blinded injections were administered by an orthopaedic surgeon and all ultrasound-guided injections were made by a radiologist experienced in this technique. All patients were injected under aseptic conditions using 40 mg/2 mL methylprednisolone acetate. The outcomes of both treatments were assessed by an independent assessor at pre-injection, then at 6-week and 3- and 6-month follow-up assessments. The assessor evaluated the q-DASH, VAS, and grip strength scores.

RESULTS

No statistically significant difference was determined between the groups in respect of the Q-DASH and grip strength scores preoperatively and at 6 weeks and 3 and 6 months post-injection. No statistically significant difference was determined between the groups in respect of the VAS scores preoperatively and at 6 weeks and 6 months. No systemic or local complications were reported during the treatment.

CONCLUSION

There was no statistically significant difference compared to the blinded injection technique, and the mean score differences between the groups are of no clinical relevance.

Midsubstance Tendinopathy, Surgical Management

Noninsertional Achilles tendinopathy often responds to nonoperative treatment. When nonoperative treatment fails, the clinician must distinguish between paratendinopathy and noninsertional tendinopathy. In paratendinopathy, myofibroblasts synthesize collagen, causing adhesions, and the paratenon may be released or excised. If a core area of tendinopathy is identified on MRI, the area is excised longitudinally and repaired with a side-to-side suture. If greater than 50% of the tendon diameter is excised, the authors recommend a short flexor hallucis longus tendon transfer with an interference screw. A turndown flap of the gastrocnemius aponeurosis is also described with good 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.

No evidence for the use of stem cell therapy for tendon disorders: a systematic review

INTRODUCTION

Stem cells have emerged as a new treatment option for tendon disorders. We systematically reviewed the current evidence for stem cell therapy in tendon disorders.

METHODS

Randomised and non-randomised controlled trials, cohort studies and case series with a minimum of 5 cases were searched in MEDLINE, CENTRAL, EMBASE, CINAHL, PEDro and SPORTDiscus. In addition, we searched grey literature databases and trial registers. Only human studies were included and no time or language restrictions were applied to our search. All references of included trials were checked for possibly eligible trials. Risk of bias assessment was performed using the Cochrane risk of bias tool for controlled trials and the Newcastle-Ottawa scale for case series. Levels of evidence were assigned according to the Oxford levels of evidence.

RESULTS

4 published and three unpublished/pending trials were found with a total of 79 patients. No unpublished data were available. Two trials evaluated bone marrow-derived stem cells in rotator cuff repair surgery and found lower retear rates compared with historical controls or the literature. One trial used allogenic adipose-derived stem cells to treat lateral epicondylar tendinopathy. Improved Mayo Elbow Performance Index, Visual Analogue Pain scale and ultrasound findings after 1-year follow-up compared with baseline were found. Bone marrow-derived stem cell-treated patellar tendinopathy showed improved International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score subscales and Tegner scores after 5-year follow-up. One trial reported adverse events and found them to be mild (eg, swelling, effusion). All trials were at high risk of bias and only level 4 evidence was available.

CONCLUSIONS

No evidence (level 4) was found for the therapeutic use of stem cells for tendon disorders. The use of stem cell therapy for tendon disorders in clinical practice is currently not advised.

Open Patellar Tendon Tenotomy and Debridement Combined with Suture-bridging Double-row Technique for Severe Patellar Tendinopathy

OBJECTIVE

To create a new surgical procedure for chronic severe patellar tendinopathy and to evaluate its clinical efficacy.

METHODS

In this retrospective study, the data of 12 patients with severe patellar tendinopathy in 14 knees who had undergone surgical treatment at Beijing Chao-Yang Hospital between 1 March 2009 and 1 August 2013 were analyzed. Inclusion criteria included severe patellar tendinopathy (Phase III), conservative therapy for more than 6 months, American Society of Anesthesiology status Grade I-II, and body mass index <30. Patients with severe osteoporosis, complete tendon disruption (Phase IV) and those who were unable to cooperate were excluded. There were 8 men (10 knees) and 4 women (4 knees) cases. The patients' ages ranged from 38 to 54 years (mean, 45.3 years). All surgeries had been performed by the same physician. Surgical treatment comprised incising open patellar midline tenotomy, complete debridement and suture-bridging double-row fixation. Isotonic and kinetic chain exercises were implemented after the second post-operative week. A gradual increase to full weight-bearing was allowed after the third post-operative week and a gradual return to unrestricted use of the leg after the eighth post-operative week. Preoperative and postoperative visual analogue scale (VAS) scores and Lysholm knee scores were obtained from the medical records or at recent postoperative follow-up visits and the results compared using Student's two-tailed paired t-test.

RESULTS

VAS scores decreased by a mean of 6.7 points (range, 1.1-7.8 points) during follow-up (minimum duration 14 months; range, 14-44 months) and Lysholm scores increased from 55.7 ± 6.5 points to 90.4 ± 6.2 points. Three cases (4 knees) achieved excellent outcomes (≥95 points) and 9 cases (10 knees) good outcomes (range, 86-94 points). No intraoperative or postoperative complications occurred. There were significant differences between preoperative and postoperative VAS and Lysholm scores (P < 0.01).

CONCLUSIONS

All study patients achieved good or excellent outcomes. No patellar tendon rupture or suture fixation failure occurred during follow-up. Suture-bridging double-row fixation is a simple and reliable method that not only improves patients' clinical symptoms, but also restores knee joint function.

Impact of Patellar Tendinopathy on Knee Proprioception: A Cross-Sectional Study

OBJECTIVE

To determine whether high-level athletes with patellar tendinopathy have diminished knee proprioceptive acuity.

DESIGN

Cross-sectional study.

SETTING

University research laboratory (institutional).

PARTICIPANTS

Twenty-one basketball and volleyball players with patellar tendinopathy (13 men and 8 women; mean age 24.5 ± 3.6; body mass index = 22.5 ± 2.0 kg/m) and an equal number of athletes without symptoms of patellar tendinopathy injury were included in this study.

ASSESSMENTS

Participants underwent knee proprioception assessments on a single day. Furthermore, age, sex, height, weight, VISA-P (Victorian Institute of Sport Assessment) questionnaire sports participation, medical history, knee injuries, previous treatment, and medication were obtained.

MAIN OUTCOME MEASURES

Knee proprioception was evaluated by assessing sense of resistance, using a weight discrimination protocol, and joint position sense (JPS).

RESULTS

No significant differences were observed in JPS at 30 and 60 degrees of knee flexion between groups (P = 0.165 and 0.481, respectively). In regard to the ability to discriminate weight, significant differences between the 2 groups were found with the tendinopathy group showing a higher percentage of error (P = 0.009), namely when the set of incremental weights varied by 10% from the standard weight.

CONCLUSIONS

Athletes with patellar tendinopathy have a diminished perception of force signals required for weight discrimination, whereas JPS remains unaffected in these athletes.

Refractory patella tendinopathy with failed conservative treatment-shock wave or arthroscopy?

AIM

To identify whether the location of refractory patella tendinopathy (PT) has an effect on treatment modality (radial extracorporeal shock wave therapy (rESWT) or arthroscopic debridement).

METHODS

Between 2012 and 2014, 40 patients with PT underwent a magnetic resonance imaging (MRI) scan. This confirmed the diagnosis as either involving the tendon itself (group A, 20) or with retropatella fat pad extension (group B, 20). All patients underwent rESWT. If there was no improvement patients proceeded with surgery in the form of arthroscopic debridement (by senior authors CW and AG). Outcomes were assessed before and after treatment using the Victorian Institute of Sports Assessment-Patella (VISA-P) score.

RESULTS

There were 18 males and 2 females in group A and 15 males and 5 females in group B. The mean age was 41.4 years in group A (23-59) and 34.7 in group B (19-52). Seventeen of 20 in group A reported good or excellent outcomes and did not require surgical intervention (remaining three improved after second course of ESWT). All patients in group B failed to improve with rESWT, resulting in arthroscopic debridement and reported good or excellent outcomes. After 6 months, group A mean VISA-P score increased from 50.2 to 65.0 ( p = 0.01) and group B from 39.6 to 78.4 ( p = <0.001).

CONCLUSION

An MRI should be performed to determine the precise location of tendinosis in patients with refractory PT who fail standard conservative management. If the MRI scan shows intratendon changes only, ESWT should be performed and those with extension into the fat pad should proceed to arthroscopic debridement without rESWT.

Corticosteroid Injections Give Small and Transient Pain Relief in Rotator Cuff Tendinosis: A Meta-analysis

BACKGROUND

The ability of injection of corticosteroids into the subacromial space to relieve pain ascribed to rotator cuff tendinosis is debated. The number of patients who have an injection before one gets relief beyond what a placebo provides is uncertain.

QUESTIONS/PURPOSES

We asked: (1) Do corticosteroid injections reduce pain in patients with rotator cuff tendinosis 3 months after injection, and if so, what is the number needed to treat (NNT)? (2) Are multiple injections better than one single injection with respect to pain reduction at 3 months?

METHODS

We systematically searched seven electronic databases for randomized controlled trials of corticosteroid injection for rotator cuff tendinosis compared with a placebo injection. Eligible studies had at least 10 adults and used pain intensity as an outcome measure. The Hedges's g as adjusted pooled standardized mean difference (SMD) (which expresses the size of the intervention effect in each study relative to the total variability observed among pooled studies) and NNT were calculated at assessment points less than 1 month, 1-2 months, and 2-3 months. The protocol of this study was registered at the international prospective register of systematic reviews. Eleven studies of 726 patients satisfied our criteria for data pooling. Three studies containing 292 patients used repeat injections. A random effects model was used owing to substantial heterogeneity among studies. The funnel plot indicated the possibility of some missing studies, but Orwin's fail-safe N and Duval and Tweedie's trim and fill suggested that missing studies would not significantly affect the results.

RESULTS

Corticosteroid injection did not reduce pain intensity in adult patients with rotator cuff tendinosis more than a placebo injection at the 3-month assessment. A small transient pain relief occurred at the assessment between 4 and 8 weeks with a SMD of 0.52 (range, 0.27-0.78) (p < 0.001). At least five patients must be treated for one patient's pain to be transiently reduced to no more than mild. Multiple injections were not found to be more effective than a single injection at any time.

CONCLUSIONS

Corticosteroid injections provide-at best-minimal transient pain relief in a small number of patients with rotator cuff tendinosis and cannot modify the natural course of the disease. Given the discomfort, cost, and potential to accelerate tendon degeneration associated with corticosteroids, they have limited appeal. Their wide use may be attributable to habit, underappreciation of the placebo effect, incentive to satisfy rather than discuss a patient's drive toward physical intervention, or for remuneration, rather than their utility.

LEVEL OF EVIDENCE

Level I, therapeutic study.

The Effectiveness of Platelet-Rich Plasma in the Treatment of Tendinopathy: A Meta-analysis of Randomized Controlled Clinical Trials

BACKGROUND

Tendinopathy is very common in the general population. There are increasing numbers of clinical studies referring to platelet-rich plasma (PRP) and platelet-poor plasma (PPP) as treatments for tendinopathy.

PURPOSE

To perform a meta-analysis of the outcomes of the PRP groups by preparation method and injection technique in tendinopathy. To determine the clinical effectiveness of the preparations and to evaluate the effect of controls used in the studies reviewed.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The PubMed, EMBASE, CINAHL, and Medline databases were searched in March 2012, April 2014, and August 2015, and randomized controlled trials using autologous blood, PRP, PPP, or autologous conditioned plasma in tendinopathy with outcome measures of pain and follow-up time of 3 months were included in this review. Trials including surgery, tendon tears, and muscle or ligament injuries were excluded. Study quality was assessed using the Cochrane Collaboration risk-of-bias tool by 2 reviewers. Data were pooled using random-effects meta-analysis. The primary outcome measure was a change in pain intensity. Where more than 1 pain scale was included, a functional score was selected ahead of a visual analog scale score.

RESULTS

A total of 18 studies (1066 participants) were included. Eight studies were deemed to be at low risk of bias. The most significant outcomes in the PRP groups were seen in those treated with highly cellular leukocyte-rich PRP (LR-PRP) preparations: GPS kit (standardized mean difference [SMD], 35.75; 95% CI, 28.40-43.10), MyCells kit (SMD, 31.84; 95% CI, 17.56-46.13), Prosys kit (SMD, 42.99; 95% CI, 37.73-48.25), and unspecified LR-PRP (SMD, 34.62; 95% CI, 31.69-37.55). When the LR-PRP system types were grouped, there was a strongly positive effect (SMD, 36.38; 95% CI, 34.00-38.77) when compared with leukocyte-poor PRP (SMD, 26.77; 95% CI, 18.31-35.22). In assessing the control groups, there was no clear difference between different types of control injections: saline (SMD, 14.62; 95% CI, 10.74-18.50), local anesthetic (SMD, 15.00; 95% CI, 7.66-22.34), corticosteroid (SMD, 23.82; 95% CI, 10.74-18.50), or dry needling (SMD, 25.22; 95% CI, 21.27-29.16).

CONCLUSION

There is good evidence to support the use of a single injection of LR-PRP under ultrasound guidance in tendinopathy. Both the preparation and intratendinous injection technique of PRP appear to be of great clinical significance.

At What Age Do Children and Adolescents Develop Lower Limb Tendon Pathology or Tendinopathy? A Systematic Review and Meta-analysis

BACKGROUND

Tendon pathology and tendinopathy have been reported in children and adolescents; however, the age at onset and prevalence of the conditions have not been examined systematically.

OBJECTIVE

To examine the prevalence of lower limb tendon pathology and tendinopathy in children and adolescents, and the factors associated with these conditions in this population.

METHODS

Six databases were searched (MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, Scopus, the Web of Science and the Allied and Complementary Medicine Database). Studies were included if the prevalence of lower limb tendon pathology and/or tendinopathy were reported in humans under the age of 18 years. Studies were divided according to the method of diagnosis (physical examination, ultrasound or a questionnaire) and further divided into studies that reported prevalence data by tendon [reported two data points (right and left) for each participant] and those that reported prevalence data for each participant [reporting one data point (right or left) per participant].

RESULTS

Seventeen studies met the inclusion criteria. Lower limb tendinopathy prevalence (presence of pain and dysfunction) ranged between 8.2 and 33.3%, and increased in prevalence as age increased up to 18 years. The odds ratio for studies reporting tendinopathy by tendon was 0.37 (95% confidence interval 0.20-0.69) in favour of boys presenting with tendinopathy. Study aims and reporting methods were heterogeneous.

CONCLUSIONS

The age at onset of lower limb tendinopathy in children and adolescents has not been widely studied. This systematic review found that tendinopathy is present in children and adolescents, and increases in prevalence with age up to 18 years. Male sex is significantly associated with tendinopathy in studies that report tendinopathy by tendon.

A systematic review of the reliability of diagnostic ultrasound imaging in measuring tendon size: Is the error clinically acceptable?

BACKGROUND

Diagnostic ultrasound (US) is a commonly used imaging modality for visualising tendon pathology and morphology. In comparison to magnetic resonance imaging (MRI), diagnostic US is perceived to have a higher risk of error when evaluating tendon size.

AIM

To systematically assess the evidence regarding the Intra rater and Inter rater reliability of diagnostic US measurements of tendon size.

DATA SOURCES

Eight electronic databases were searched using an agreed set of keywords. Studies which investigated the reliability of tendon size (thickness or cross sectional area) using diagnostic US were eligible.

RESULTS

Combined Inter rater and Intra rater ICC values for tendon thickness ranged from 0.45 to 0.99. Combined Inter rater and Intra rater ICC values for tendon cross-sectional area (CSA) ranged from 0.58 to 0.92. Overall, Intra rater ICC values (0.59-0.99) were marginally higher than Inter rater values (0.45-0.99) across all tendon sites. Percentage co-efficient of variation (CV%) for tendon thickness and CSA ranged from 0 to 35% across all tendons. Percentage standard error of the mean SEM% values for tendon thickness ranged from 3.33% to 7.39%.

CONCLUSIONS

The findings of this review suggest diagnostic US measures of tendon size are reliable, both in terms of relative and absolute reliability. However, the findings must be considered in light of the presence of tendon abnormalities in a large percentage of asymptomatic populations.

Athletic training affects the uniformity of muscle and tendon adaptation during adolescence

With the double stimulus of mechanical loading and maturation acting on the muscle-tendon unit, adolescent athletes might be at increased risk of developing imbalances of muscle strength and tendon mechanical properties. This longitudinal study aims to provide detailed information on how athletic training affects the time course of muscle-tendon adaptation during adolescence. In 12 adolescent elite athletes (A) and 8 similar-aged controls (C), knee extensor muscle strength and patellar tendon mechanical properties were measured over 1 yr in 3-mo intervals. A linear mixed-effects model was used to analyze time-dependent changes and the residuals of the model to quantify fluctuations over time. The cosine similarity (CS) served as a measure of uniformity of the relative changes of tendon force and stiffness. Muscle strength and tendon stiffness increased significantly in both groups ( P < 0.01). However, the fluctuations of muscle strength were greater [A, 17 ± 7 (SD) N·m; C, 6 ± 2 N·m; P < 0.05] and the uniformity of changes of tendon force and stiffness was lower in athletes (CS A, −0.02 ± 0.5; C, 0.5 ± 0.4; P < 0.05). Further, athletes demonstrated greater maximum tendon strain (A, 7.6 ± 1.7%; C, 5.5 ± 0.9%; P < 0.05) and strain fluctuations (A, 0.9 ± 0.4; C, 0.3 ± 0.1; P < 0.05). We conclude that athletic training in adolescence affects the uniformity of muscle and tendon adaptation, which increases the demand on the tendon with potential implications for tendon injury.

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.

Autologous whole blood or corticosteroid injections for the treatment of epicondylopathy and plantar fasciopathy? A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To compare the efficacy of autologous whole blood with that of corticosteroid injections on epicondylopathy and plantar fasciopathy.

DESIGN

Systematic review and meta-analysis.

METHODS

The databases of PubMed, Web of Science, CENTRAL, and Scopus were searched up to 6th May 2015. Randomized trials comparing the effects of autologous whole blood and corticosteroid injections on epicondylopathy or plantar fasciopathy were included. Trials exploring the efficacy of platelet-rich plasma were excluded. The primary outcome was pain relief. The secondary outcome included the assessment of composite outcomes. All outcomes were assessed at 2-6 (short-term) weeks, 8-13 (intermediate-term) weeks and 24-26 (medium-term) weeks. Quality assessment was performed with the Cochrane risk of bias tool.

RESULTS

Nine trials were included. For pain relief, there was a statistically significant difference in favour of corticosteroids in the short term (SMD 0.52; 95%CIs 0.18 to 0.86; I² = 53%; p < 0.01). A statistically significant difference in favour of autologous whole blood was indicated in the medium-term assessment of pain relief on epicondylopathy.

CONCLUSIONS

Corticosteroids were marginally superior to autologous whole blood in relieving pain on plantar fasciopathy at 2-6 weeks. Autologous whole blood provided significant clinical relief on epicondylopathy at 8-24 weeks. Conclusions were limited by the risk of bias.

Effects of platelet-rich plasma on lateral epicondylitis of the elbow: prospective randomized controlled trial

Objective

To evaluate the effects of platelet-rich plasma (PRP) infiltration in patients with lateral epicondylitis of the elbow, through analysis of the Disabilities of the Arm, Shoulder and Hand (DASH) and Patient-Rated Tennis Elbow Evaluation (PRTEE) questionnaires.

Methods

Sixty patients with lateral epicondylitis of the elbow were prospectively randomized and evaluated after receiving infiltration of three milliliters of PRP, or 0.5% neocaine, or dexamethasone. For the scoring process, the patients were asked to fill out the DASH and PRTEE questionnaires on three occasions: on the day of infiltration and 90 and 180 days afterwards.

Results

Around 81.7% of the patients who underwent the treatment presented some improvement of the symptoms. The statistical tests showed that there was evidence that the cure rate was unrelated to the substance applied (p = 0.62). There was also intersection between the confidence intervals of each group, thus demonstrating that the proportions of patients whose symptoms improved were similar in all the groups.

Conclusion

At a significance level of 5%, there was no evidence that one treatment was more effective than another, when assessed using the DASH and PRTEE questionnaires.

Eccentric or Concentric Exercises for the Treatment of Tendinopathies?

Synopsis Tendinopathy is a very common disorder in both recreational and elite athletes. Many individuals have recurrent symptoms that lead to chronic conditions and termination of sports activity. Exercise has become a popular and somewhat efficacious treatment regime, and isolated eccentric exercise has been particularly promoted. In this clinical commentary, we review the relevant evidence for different exercise regimes in tendinopathy rehabilitation, with particular focus on the applied loads that are experienced by the tendon and how the exercise regime may affect these applied loads. There is no convincing clinical evidence to demonstrate that isolated eccentric loading exercise improves clinical outcomes more than other loading therapies. However, the great variation and sometimes insufficient reporting of the details of treatment protocols may hamper the interpretation of what may be the optimal exercise regime with respect to parameters such as load magnitude, speed of movement, and recovery period between exercise sessions. Future studies should control for these loading parameters, evaluate various exercise dosages, and think beyond isolated eccentric exercises to arrive at firm recommendations regarding rehabilitation of individuals with tendinopathies. J Orthop Sports Phys Ther 2015;45(11):853-863. Epub 14 Oct 2015. doi:10.2519/jospt.2015.5910.

Should We Care About Tendon Structure? The Disconnect Between Structure and Symptoms in Tendinopathy

We can visualize tendons better than ever before. Medical imaging today provides increasingly higher-resolution images, enabling larger fields of view that allow clinicians and researchers to more precisely characterize tendon structure. Yet, does seeing a patient's tendon provide any meaningful benefit to our clinical reasoning, and will it make a difference to treatment outcomes? It is little surprise that concomitant with this imaging availability is a renewed debate over the relationship between the appearance of tendon structure and symptomology. Despite the advances in medical imaging, as well as the clinical and research interest in tendinopathy, there does not appear to be any greater clarity on reconciling a patient's clinical presentation with either baseline characterization of structural abnormalities or the time series of changes following selected interventions. It may be helpful, therefore, to take a step back and give renewed consideration to the anatomical and physiological role of tendon structure, and to consider this in the context of what we know about tendon pathology. J Orthop Sports Phys Ther 2015;45(11):823-825. doi:10.2519/jospt.2015.0112.