Genetic aspects of tendinopathy

Challenges and opportunities of medicines for treating tendon inflammation and fibrosis: A comprehensive and mechanistic review

BACKGROUND

Tendinopathy refers to conditions characterized by collagen degeneration within tendon tissue, accompanied by the proliferation of capillaries and arteries, resulting in reduced mechanical function, pain, and swelling. While inflammation in tendinopathy can play a role in preventing infection, uncontrolled inflammation can hinder tissue regeneration and lead to fibrosis and impaired movement.

OBJECTIVES

The inability to regulate inflammation poses a significant limitation in tendinopathy treatment. Therefore, an ideal treatment strategy should involve modulation of the inflammatory process while promoting tissue regeneration.

METHODS

The current review article was prepared by searching PubMed, Scopus, Web of Science, and Google Scholar databases. Several treatment approaches based on biomaterials have been developed.

RESULTS

This review examines various treatment methods utilizing small molecules, biological compounds, herbal medicine-inspired approaches, immunotherapy, gene therapy, cell-based therapy, tissue engineering, nanotechnology, and phototherapy.

CONCLUSION

These treatments work through mechanisms of action involving signaling pathways such as transforming growth factor-beta (TGF-β), mitogen-activated protein kinases (MAPKs), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), all of which contribute to the repair of injured tendons.

Histological, Physiological and Biomechanical Effects of Low-Level Laser Therapy on Tendon Healing in Animals and Humans: A Systematic Review

Low-level Laser Therapy (LLLT) was widely used in clinical practice for tendon disorders. However, the underlying mechanisms and effectiveness of LLLT in treating tendon injury remain unclear. Therefore, the present study was conducted aiming to summarize the evidence regarding the histological, physiological, and biomechanical effects of LLLT on tendon healing in animal and human models. Four databases were searched for relevant literature. Four independent reviewers screened abstracts and full-text articles, extracted relevant data, evaluated the risk of bias, and quantified the quality of evidence. Database searches yielded 1400 non-duplicated citations. Fifty-five studies were included (50 animal and five human studies). Animal studies revealed that LT had stimulating effects on collagen organization, collagen I and collagen II formation, matrix metalloproteinase (MMP)-8, transforming growth factor β1, vascular endothelial growth factor, hydroxyproline, maximum load, maximum elongation before breaking, and tendon stiffness. However, LLLT had inhibitory effects on the number of inflammatory cells, histological scores, relative amount of collagen III, cyclooxygenase-2, prostaglandin E2 (PGE2), interleukin-6, tumor necrosis factor-α, MMP-1, and MMP-3. Although one human study found that LLLT reduced the concentration of PGE2 in peritendinous tissue of the Achilles tendon, other human studies revealed that the effects of LLLT on the physiology and biomechanics of human tendons remained uncertain. LLLT facilitates tendon healing through various histological, physiological, and biomechanical effects in animal models. Only post-LLLT anti-inflammatory effects were found in human studies.

Patellar tendinopathy: an overview of prevalence, risk factors, screening, diagnosis, treatment and prevention

Patellar tendinopathy (PT), or jumper's knee, is an overuse injury that occurs in professional, as well as recreational, athletes. This condition is a noncontact injury, typically characterized by gradually increasing pain in the patellar tendon. It is prevalent in participants of several sports, but it occurs mostly in jumping sports. The diagnosis of PT is primarily clinical; however, imaging techniques can be useful as well. Risk factors differ between sexes, playing conditions, the kind of sport, playing level and personal characteristics. Screening is an essential tool to assess PT. This condition affects athletic performance and often persists for years. The use of preventative methods is imperative because of the persistence of this condition, especially in elite athletes who sometimes end their career after long and failed treatments. There are a wide variety of treatment and rehabilitation options available, the majority of which are non-operative, such as eccentric exercises, cryotherapy, platelet-rich plasma (PRP) injections, and anti-inflammatory strategies. If conservative treatment fails, surgery is the next most preferable step. Even though there are many surgical treatment methods, there is no clear evidence on what is the most effective approach to address PT. Taking this into consideration, as well as the extent of this clinical entity, novel therapeutic techniques, as well as screening and prevention methods, are expected to emerge in the near future.

Association between Body Weight and Body Mass Index and Patellar Tendinopathy in Elite Basketball and Volleyball Players, a Systematic Review and Meta-Analysis

The features of Patellar-Tendinopathy are (1): pain localised to the inferior pole of the patellar; (2): the presence of load-related pain. Body-Weight and Body-Mass-Index, as two easily-measured variables, could potentially aid the prediction of PT. This review aims to establish relationships between Body-Weight and Body-Mass-Index and Patellar-Tendinopathy via synthesising the evidence from prospective-cohort and cross-sectional studies in elite basketball and volleyball players. Seven databases (PubMed, EMBASE, CINAHL, Google Scholar, Health-Management-Information-Consortium, National-Technical-Information-Service, ClinicalTrial.gov) and citation chasing were used to identify English peer-review articles from 2000 to 2022. An adapted version of the Newcastle-Ottawa scale was used for critical appraisal. Two reviewers were involved in literature searching, data extraction, and quality review. Two prospective cohort and five cross-sectional studies met the inclusion criteria, providing 849 subjects (male:female: 436:413). Five studies found BW is associated with PT. Three studies found a relationship between BMI and PT. Six out of seven studies were classified as very good studies. All studies were level IV evidence. The very low certainty evidence suggests an association between BW and PT. There is moderate certainty evidence that BMI is associated with PT. These preliminary findings should be treated cautiously due to the lack of strong evidence.

Why Use Adipose-Derived Mesenchymal Stem Cells in Tendinopathic Patients: A Systematic Review

The aim of the present systematic review was to provide a clear overview of the clinical current research progress in the use of adipose-derived mesenchymal stem cells (ASCs) as an effective therapeutic option for the management of tendinopathies, pathologies clinically characterized by persistent mechanical pain and structural alteration of the tendons. The review was carried out using three databases (Scopus, ISI Web of Science and PubMed) and analyzed records from 2013 to 2021. Only English-language papers describing the isolation and manipulation of adipose tissue as source of ASCs and presenting ASCs as treatment for clinical tendinopathies were included. Overall, seven clinical studies met the inclusion criteria and met the minimum quality inclusion threshold. Data extraction and quality assessment were performed by groups of three reviewers. The available evidence showed the efficacy and safety of ASCs treatment for tendinopathies, although it lacked a clear description of the biomolecular mechanisms underlying the beneficial properties of ASCs.

Analysis of the lncRNA-Associated Competing Endogenous RNA (ceRNA) Network for Tendinopathy

Background

We aimed to construct the lncRNA-associated competing endogenous RNA (ceRNA) network and distinguish feature lncRNAs associated with tendinopathy.

Methods

We downloaded the gene profile of GSE26051 from the Gene Expression Omnibus (GEO), including 23 normal samples and 23 diseased tendons. Differentially expressed mRNAs (DEmRNAs) and differentially expressed lncRNAs (DElncRNAs) were identified, and functional and pathway enrichment analyses were performed. Protein-protein interaction (PPI) network was constructed and further analyzed by module mining. Moreover, a ceRNA regulatory network was constructed based on the identified lncRNA–mRNA coexpression relationship pairs and miRNA–mRNA regulation pairs.

Results

We identified 1117 DEmRNAs and 57 DElncRNAs from the GEO data. The downregulated DEmRNAs were particularly associated with muscle contraction and muscle filament, while the upregulated ones were linked to extracellular matrix organization and cell adhesion. From the PPI network, 11 modules were extracted. Genes in MCODE 2 (such as TPM4) were significantly involved in cardiomyopathy, and genes in MCODE 4 (such as COL4A3 and COL4A4) were involved in focal adhesion, ECM-receptor interaction, and PI3K-Akt signaling pathway. The ceRNA network contained 7 lncRNAs (MIR133A1HG, LINC01405, PRKCQ-AS1, C10orf71-AS1, MBNL1-AS1, HOTAIRM1, and DNM3OS), 63 mRNAs, and 41 miRNAs. Downregulated lncRNA MIR133A1HG could competitively bind with hsa-miR-659-3p and hsa-miR-218-1-3p to regulate the TPM3. Meanwhile, MIR133A1HG could competitively bind with hsa-miR-1179 to regulate the COL4A3. Downregulated C10orf71-AS1 could competitively bind with hsa-miR-130a-5p to regulate the COL4A4.

Conclusions

Seven important lncRNAs, particularly MIR133A1HG and C10orf71-AS1, were found associated with tendinopathy according to the lncRNA-associated ceRNA network.

Achilles tendon surgery in clubfoot: Are long term sequelae predictable?

Congenital Clubfoot (CCF) treatment involves a surgical procedure on the Achilles tendon most of the time, i.e. tenotomy or, in selected cases, Z-plasty lengthening. Many authors have studied the outcomes of Achilles tenotomy, describing complete clinical and ultrasound tendon fibers integrity restoration 3-6 weeks after surgery. Nevertheless, little is known about the mechanical properties of the operated tendon. Recently, cases of subcutaneous rupture of the Achilles tendon have been described in adolescents who practiced sports and who had undergone Achilles tenotomy for congenital clubfoot in childhood. Authors report two cases of atraumatic Achilles tendon injury (subcutaneous rupture and intratendinous ossification) in adult patients who had been treated for congenital clubfoot in childhood. In both cases, no causes determining the injury were identified; in the medical history there was a Z-plasty lengthening of the Achilles tendon, performed within the first year of life, which could be considered a predisposing factor. The usefulness of long-term monitoring of patients treated for CCF with surgical procedures on the Achilles tendon is therefore hypothesized, in order to promptly identify by symptoms, clinical pictures and ultrasound criteria, tendon suffering that may predispose subcutaneous rupture.

The role of familial predisposition in imaging-confirmed atraumatic rotator cuff tears

BACKGROUND

The etiology of atraumatic rotator cuff tears is not completely understood. Limited data suggest the role of genetic and familial predisposition in the etiology of rotator cuff tears. The purpose of this study was to assess whether there is an increased likelihood of rotator cuff tears in family members of patients with rotator cuff tears vs. those without tears. This would provide evidence for whether there is an association between familial predisposition and rotator cuff tearing.

METHODS

Patients presenting to a shoulder clinic were recruited in this study. They provided information on personal medical history, shoulder symptoms, and family history of rotator cuff tears. The diagnosis of rotator cuff tears was based on imaging (magnetic resonance imaging or computed tomography arthrogram) confirmation of a structural defect in the rotator cuff. The association between family history of rotator cuff problems and the likelihood of an imaging-confirmed rotator cuff tear diagnosis was evaluated using multivariate logistic regression, adjusting for age, sex, race/ethnicity, cigarette smoking, hypertension, diabetes, and depression.

RESULTS

In our cohort of 2335 patients, 52.6% (n = 1229) of patients had a rotator cuff tear. Among patients with tears, 17.9% (n = 220) of patients reported a family history of rotator cuff issues vs. 11.1% (n = 123) in patients without tears. A family history of rotator cuff problems was significantly associated with the diagnosis of an imaging-confirmed rotator cuff tear (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.71, 2.95). Other confounding variables such as increasing age (OR 1.06, 95% CI 1.05, 1.07) and Hispanic race/ethnicity as compared to non-Hispanic white race/ethnicity (OR 1.48, 95% CI 1.07, 2.05) were significantly associated with rotator cuff tears. Sex, smoking, hypertension, diabetes, and depression were not significantly associated with rotator cuff tearing.

CONCLUSION

Our study shows that individuals with rotator cuff tears were more than 2 times as likely to have a family member with a tear as compared to patients without tears. Increasing age and patients who identified as being of Hispanic ancestry were also significantly associated with higher odds of rotator cuff tears.

Coordinate roles for collagen VI and biglycan in regulating tendon collagen fibril structure and function

Tendon is a vital musculoskeletal tissue that is prone to degeneration. Proper tendon maintenance requires complex interactions between extracellular matrix components that remain poorly understood. Collagen VI and biglycan are two matrix molecules that localize pericellularly within tendon and are critical regulators of tissue properties. While evidence suggests that collagen VI and biglycan interact within the tendon matrix, the relationship between the two molecules and its impact on tendon function remains unknown. We sought to elucidate potential coordinate roles of collagen VI and biglycan within tendon by defining tendon properties in knockout models of collagen VI, biglycan, or both molecules. We first demonstrated co-expression and co-localization of collagen VI and biglycan within the healing tendon, providing further evidence of cooperation between the two molecules during nascent tendon matrix formation. Deficiency in collagen VI and/or biglycan led to significant reductions in collagen fibril size and tendon mechanical properties. However, collagen VI-null tendons displayed larger reductions in fibril size and mechanics than seen in biglycan-null tendons. Interestingly, knockout of both molecules resulted in similar properties to collagen VI knockout alone. These results indicate distinct and non-additive roles for collagen VI and biglycan within tendon. This work provides better understanding of regulatory interactions between two critical tendon matrix molecules.

Tendon Tissue Repair in Prospective of Drug Delivery, Regenerative Medicines, and Innovative Bioscaffolds

The natural healing capacity of the tendon tissue is limited due to the hypovascular and cellular nature of this tissue. So far, several conventional approaches have been tested for tendon repair to accelerate the healing process, but all these approaches have their own advantages and limitations. Regenerative medicine and tissue engineering are interdisciplinary fields that aspire to develop novel medical devices, innovative bioscaffold, and nanomedicine, by combining different cell sources, biodegradable materials, immune modulators, and nanoparticles for tendon tissue repair. Different studies supported the idea that bioscaffolds can provide an alternative for tendon augmentation with an enormous therapeutic potentiality. However, available data are lacking to allow definitive conclusion on the use of bioscaffolds for tendon regeneration and repairing. In this review, we provide an overview of the current basic understanding and material science in the field of bioscaffolds, nanomedicine, and tissue engineering for tendon repair.

Management of Achilles and patellar tendinopathy: what we know, what we can do

Tendinopathies are challenging conditions frequent in athletes and in middle-aged overweight patients with no history of increased physical activity. The term “tendinopathy” refers to a clinical condition characterised by pain, swelling, and functional limitations of tendons and nearby structures, the effect of chronic failure of healing response. Tendinopathies give rise to significant morbidity, and, at present, only limited scientifically proven management modalities exist. Achilles and patellar tendons are among the most vulnerable tendons, and among the most frequent lower extremity overuse injuries. Achilles and patellar tendinopathies can be managed primarily conservatively, obtaining good results and clinical outcomes, but, when this approach fails, surgery should be considered. Several surgical procedures have been described for both conditions, and, if performed well, they lead to a relatively high rate of success with few complications. The purpose of this narrative review is to critically examine the recent available scientific literature to provide evidence-based opinions on these two common and troublesome conditions.

Lower Extremities Strength Differences in Female Volleyball Players With Stage 1 Patellar Tendinopathy

Kabacinski, J, Murawa, M, Fryzowicz, A, Gorwa, J, and Dworak, LB. Lower extremities strength differences in female volleyball players with stage 1 patellar tendinopathy. J Strength Cond Res XX(X): 000-000, 2020-The main purpose of the study was to compare the muscle strength between the involved knee (IK) and uninvolved knee (UK) in 12 female volleyball players with stage 1 chronic patellar tendinopathy. Evaluation included the isometric maximal strength to body mass (MS/BM) of the lower extremities extensors for unilateral and bilateral conditions, concentric isokinetic peak torque to body mass (PT/BM) of the hamstrings and quadriceps at 60°·s and 180°·s, IK to UK extensors maximal strength ratio (SR), IK to UK hamstrings (or quadriceps) peak torque ratio (TR), and hamstrings to quadriceps peak TR (H/Q). The results indicated a significantly lower unilateral and bilateral MS/BM of lower extremities extensors for IK than UK (p < 0.001). However, there were no significant differences in SR variable between the unilateral condition and bilateral condition (p = 0.448). Only at the 60°·s velocity, significantly lower quadriceps PT/BM for IK compared with the UK (p < 0.001) and the control group (p < 0.001) were observed. Torque ratio related to the quadriceps group was significantly lower at 60°·s than 180°·s (p = 0.004). Furthermore, significantly higher H/Q for IK compared with UK (p < 0.001) and control group (p = 0.008) only at 60°·s was found. These findings show a significant isometric strength asymmetry for both unilateral and bilateral conditions and a significant concentric strength asymmetry at the low velocity. This study suggests strengthening the weaker quadriceps group and balancing the strength between hamstrings and quadriceps within the knee with patellar tendinopathy.

Acute distal biceps tendon ruptures: anatomy, pathology and management - state of the art

All patients with acute complete distal biceps tendon ruptures who are not low demand or medically unfit to proceed with surgery are offered operative repair. This restores arm shape, supination strength and function, and decreases their cramping symptoms. Surgical repair technique varies significantly depending on location and training centre. Nuances in technique and appropriate implant selection need to be noted in order to achieve a strong repair allowing early active range of motion. Intimate knowledge of distal biceps tendon anatomy is key to avoid complications associated with the different approaches. The cumulative body of evidence on complications, coupled with knowledge of the different biomechanical construct strengths of the alternative methods of fixation, points to the use of the cortical button technique without the addition of an interference screw. Subtle variations in drill hole positioning on the bicipital tuberosity secures either an anatomic or non-anatomic repair. Anatomic repair results in greater supination peak torque and fatigue strength, and in greater flexion fatigue strength. It is advisable to perform an anatomic repair in elite athletes or those patients who significantly rely on supination strength and endurance for their livelihood. A universal postoperative protocol is suggested for all repairs.

A Cross-Sectional Study on Novel-Risk Factors Associated with Supraspinatus Tendon Tear

BACKGROUND AND AIM

Several patient-related factors have been identified which are responsible for the development of rotator cuff tears. The purpose of the study was to assess various parameters which can be risk factors for the development of supraspinatus tendon tear.

METHODS

A total of 100 patients with symptomatic rotator cuff tear, aged > 18 years, of either gender, presenting to the outpatient department were included in this cross-sectional study. Magnetic resonance imaging was done and based on its results; patients were identified for the type of tear. Demographic, clinical, and biochemical factors affecting the tears were assessed using logistic regression analysis.

RESULTS

Factors such as age, gender, pain radiation, night pain, and analgesic intake had significant association with supraspinatus tendon tears.

CONCLUSION

"Pain radiation" and "Analgesic intake" were two new parameters found associated with the supraspinatus tendon tears. New parameters that have been assessed as risk factors will help in better understanding of supraspinatus tendon tears.

Predisposição familiar para rotura do manguito rotador e outras tendinopatias – Um estudo de caso-controle

Objective  To evaluate the prevalence of family history of rotator cuff tear and the presence of tendinopathy in other joints in patients with rotator cuff tears and to compare them with paired controls. To estimate the odds ratio for rotator cuff tear for these two risk factors.

Methods  We performed a case-control study comparing patients submitted to treatment for rotator cuff tear with asymptomatic controls. All cases and controls were evaluated by imaging exams and matched by age (±2 years) and gender. We conducted an interview using a standardized questionnaire, and collected data on various risk factors.

Results  We evaluated 144 patients, 72 per group. Patients with rotator cuff tears reported a higher number of consanguineous relatives who underwent treatment for the same disease and tendon injuries in other joints compared to the controls ( p  = 0.005 and p  = 0.045 respectively). Individuals with a family history of treatment for rotator cuff tear or with tendinopathies in other joints were more likely to present a rotator cuff tear, with odds ratios of 3.3 (95% confidence interval [95%CI] = 1.4–7.7) and 2.7 (95%CI = 1.1–6.9) respectively.

Conclusions  Patients with rotator cuff tear have a higher prevalence of family members with the same disease and tendinopathies or tendon injuries in other joints. The presence of consanguineous relatives with treatment for rotator cuff and tendinopathies in other joints are risk factors for the presence of rotator cuff tears.

Achilles Tendon Lesions - Part 1: Tendinopathies

Calcaneal tendon injuries are extremely common in the general population and in orthopedics routine care. Its increasing incidence, which is motivated by an aging population, improved access to the health care system, increased prescription of continuous-use medication, erratic participation in sports and other factors, has had a direct impact on society. Consolidated treatment options for tendinopathies lack quality scientific support for many modalities. New therapies have emerged to enhance nonsurgical approach outcomes and to reduce the number of patients requiring surgery. Although these operative procedures provide good pain relief and functional outcomes, they are costly and may lead to complications.

Genomic Prediction of Tendinopathy Risk in Elite Team Sports

PURPOSE

The authors investigated the association between risk of tendinopathies and genetic markers in professional team sports.

METHODS

The authors studied 363 (mean [SD]; 25 [6] y, 89% male) elite players (soccer, futsal, basketball, handball, and roller hockey) from a top-level European team (FC Barcelona, Spain). Of 363, 55% (cases) had experienced 1+ episodes of tendinopathy during 2008-2018 and 45% (controls) remained injury free. The authors first examined the association between single-nucleotide polymorphisms (SNPs) and tendinopathy risk in a hypothesis-free case-control genome-wide association study (495,837 SNPs) with additional target analysis of 58 SNPs that are potential candidates to influence tendinopathy risk based on the literature. Thereafter, the authors augmented the SNP set by performing synthetic variant imputation (1,419,369 SNPs) and then used machine learning-based multivariate modeling (support vector machine and random forest) to build a reliable predictive model.

RESULTS

Suggestive association (P < 10-5) was found for rs11154027 (gap junction alpha 1), rs4362400 (vesicle amine transport 1-like), and rs10263021 (contactin-associated protein-like 2). Carriage of 1+ variant alleles for rs11154027 (odds ratio = 2.11; 95% confidence interval, 1.07-4.19, P = 1.01 × 10-6) or rs4362400 (odds ratio = 1.98; 95% confidence interval, 1.05-3.73, P = 9.6 × 10-6) was associated with a higher risk of tendinopathy, whereas an opposite effect was found for rs10263021 (odds ratio = 0.42; 95% confidence interval, 0.20-0.91], P = 4.5 × 10-6). In the modeling approach, one of the most robust SNPs was rs10477683 in the fibrillin 2 gene encoding fibrillin 2, a component of connective tissue microfibrils involved in elastic fiber assembly.

CONCLUSIONS

The authors have identified previously undescribed genetic predictors of tendinopathy in elite team sports athletes, notably rs11154027, rs4362400, and rs10263021.

Tendon healing in presence of chronic low-level inflammation: a systematic review

BACKGROUND

Tendinopathy is a common musculoskeletal condition affecting subjects regardless of their activity level. Multiple inflammatory molecules found in ex vivo samples of human tendons are related to the initiation or progression of tendinopathy. Their role in tendon healing is the subject of this review.

SOURCES OF DATA

An extensive review of current literature was conducted using PubMed, Embase and Cochrane Library using the term 'tendon', as well as some common terms of tendon conditions such as 'tendon injury OR (tendon damage) OR tendonitis OR tendinopathy OR (chronic tendonitis) OR tendinosis OR (chronic tendinopathy) OR enthesitis' AND 'healing' AND '(inflammation OR immune response)' as either key words or MeSH terms.

AREAS OF AGREEMENT

An environment characterized by a low level of chronic inflammation, together with increased expression of inflammatory cytokines and growth factors, may influence the physiological tendon healing response after treatment.

AREAS OF CONTROVERSY

Most studies on this topic exhibited limited scientific translational value because of their heterogeneity. The evidence associated with preclinical studies is limited.

GROWING POINTS

The role of inflammation in tendon healing is still unclear, though it seems to affect the overall outcome. A thorough understanding of the biochemical mediators of healing and their pathway of pain could be used to target tendinopathy and possibly guide its management.

AREAS TIMELY FOR DEVELOPING RESEARCH

We require further studies with improved designs to effectively evaluate the pathogenesis and progression of tendinopathy to identify cellular and molecular targets to improve outcomes.

Nivel de satisfacción sobre la seguridad y complicaciones a cuatro años de la introducción de la técnica Microelectrólisis Percutánea (MEP®) Sport como práctica fisioterapéutica

RESUMEN El objetivo de este trabajo es investigar la experiencia de los fisioterapeutas formados en microeletrólisis percutánea sport y conocer la cantidad de aplicaciones realizadas semanalmente, los efectos adversos presentados y el nivel de satisfacción de los terapeutas con sus pacientes. Se realizó una encuesta que evaluó la opinión y la experiencia de profesionales certificados en microelectrolisis percutánea sport. Los datos fueron obtenidos a través de la plataforma virtual SurveyMonkey, enviando por correo electrónico una invitación a 1.096 fisioterapeutas de América Latina. Respondieron el cuestionario 315 profesionales, entre los cuales 165 (56,51%) atienden de uno a cinco pacientes por semana. Las respuestas sobre efectos adversos fueron: nunca he tenido complicaciones (56,79% - 159 respuestas); choque hipotensivo (19,64% - 55 respuestas.); alergia al metal (5,36% - 15 respuestas). Los sitios/patologías a que más se aplican la microelectrolisis percutánea sport son: tendón rotuliano (10,77% - 198 respuestas.); tendón de aquiles (9,58% - 176 respuestas); tendón supraespino (9,36% - 172 respuestas.); fascitis plantar/espolón calcáneo (8,05% - 148 respuestas.); y puntos-gatillo (7,18% - 132 respuestas.). La satisfacción de los profesionales fue: satisfecho (51,87% - 152 respuestas) y muy satisfecho (40,96% - 120 respuestas). Las respuestas de los pacientes fueron: satisfecho (61,90% - 182 respuestas) y muy satisfecho (29,93% - 88 respuestas). La técnica MEP se aplica principalmente en tendinopatías y produce resultados satisfactorios y muy satisfactorios tanto para los pacientes como para los terapeutas, con baja presencia de efectos adversos.

Nonsurgical Treatments of Patellar Tendinopathy: Multiple Injections of Platelet-Rich Plasma Are a Suitable Option: A Systematic Review and Meta-analysis

BACKGROUND

Patellar tendinopathy is a condition characterized by anterior knee activity-related pain. It has a high incidence among athletes engaged in jumping sports and may become a chronic condition. Nonoperative management is the first choice in these patients, and several nonsurgical treatment options have been proposed. Nonetheless, clear indications on the most effective approach to address patellar tendinopathy are still lacking.

PURPOSE

To analyze the evidence on nonoperative options to treat chronic patellar tendinopathy through a systematic review of the literature and to perform a meta-analysis to identify the most effective nonsurgical option.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The search was conducted with the PubMed and Cochrane databases on January 4, 2017. All clinical English-language reports of any level of evidence on nonsurgical treatment of patellar tendinopathy were included. The quality of each article was assessed by use of the Coleman score. A meta-analysis was performed on all articles reporting the Victorian Institute of Sport Assessment scale for patellar tendinopathy to evaluate the results of the most described treatments.

RESULTS

A total of 70 studies involving 2530 patients were included in the qualitative data synthesis. The Coleman score showed an overall poor study quality. The most described treatment groups that could be included in the meta-analysis were reported in 22 studies on eccentric exercise, extracorporeal shockwave therapy (ESWT), and platelet-rich plasma (PRP). Single and multiple PRP injections were evaluated separately. Eccentric exercise therapies obtained the best results ( P < .05) at short-term (<6 months, mean 2.7 ± 0.7 months). However, multiple injections of PRP obtained the best results ( P < .05), followed by ESWT and eccentric exercise, at long-term follow-up (≥6 months, mean 15.1 ± 11.3 months).

CONCLUSION

The literature documents several nonsurgical approaches for the treatment of chronic patellar tendinopathy with important limitations in terms of study quality. The available evidence showed an overall positive outcome, but some differences have been highlighted. Eccentric exercises may seem the strategy of choice in the short-term, but multiple PRP injections may offer more satisfactory results at long-term follow-up and can be therefore considered a suitable option for the treatment of patellar tendinopathy.

Short-term Changes After Corticosteroid Injections Into the Normal Tendons of Rabbits: A Controlled Randomized Study

BACKGROUND

Corticosteroid injections in or around tendons for the treatment of athletic injuries are a common practice among orthopaedic surgeons and are apparently efficacious in the short term, although controversies persist related to local complications.

PURPOSE

This study evaluated short-term (48 hours) biomechanical, biochemical, and histological alterations after a single injection of betamethasone into the normal tendons of rabbits.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 72 New Zealand White rabbits were randomly divided into 2 groups: the test group-in which 36 animals underwent 1 intratendinous injection of betamethasone (1.4 mg / 0.2 mL) in the right calcaneal tendon; the control group-in which the right calcaneal tendon of 36 animals was injected with saline (placebo control group) and the left calcaneal tendon was left untreated for normal standards (normal control). Forty-eight hours later, animals were euthanized and tendons were harvested. Metalloproteinase (MMP1 and MMP2) and interleukin (IL1 and IL6) expression levels, biomechanical resistance (load × elongation parameters), and histomorphometry (hematoxylin and eosin and picrosirius red stains for collagen fibers, tenocytes, and inflammatory cells) were analyzed in the tendons.

RESULTS

The test group had a significant reduction in MMP2 expression as compared with the control groups ( P = .027). Regarding the other parameters, there were no additional significant differences between the groups.

CONCLUSION

A single injection of corticosteroid into normal calcaneal tendons did not trigger acute local morphological, structural, or biomechanical injuries at 48 hours, but it did promote a significant decrease in MMP2 levels. Additional studies are needed with increased duration of follow-up, various doses, and multiple injections and in tendinopathic models.

CLINICAL RELEVANCE

Some previous studies demonstrated early structural changes in tendons after a single corticosteroid injection, which was not corroborated by the present study. Metalloproteinase decrease is usually associated with a reduction in collagen degradation, which would be protective for the healing process. More studies are necessary to confirm the possible beneficial effect of these results in the long term and for tendinopathies.

Overuse injuries in sport: a comprehensive overview

BACKGROUND

The absence of a single, identifiable traumatic cause has been traditionally used as a definition for a causative factor of overuse injury. Excessive loading, insufficient recovery, and underpreparedness can increase injury risk by exposing athletes to relatively large changes in load. The musculoskeletal system, if subjected to excessive stress, can suffer from various types of overuse injuries which may affect the bone, muscles, tendons, and ligaments.

METHODS

We performed a search (up to March 2018) in the PubMed and Scopus electronic databases to identify the available scientific articles about the pathophysiology and the incidence of overuse sport injuries. For the purposes of our review, we used several combinations of the following keywords: overuse, injury, tendon, tendinopathy, stress fracture, stress reaction, and juvenile osteochondritis dissecans.

RESULTS

Overuse tendinopathy induces in the tendon pain and swelling with associated decreased tolerance to exercise and various types of tendon degeneration. Poor training technique and a variety of risk factors may predispose athletes to stress reactions that may be interpreted as possible precursors of stress fractures. A frequent cause of pain in adolescents is juvenile osteochondritis dissecans (JOCD), which is characterized by delamination and localized necrosis of the subchondral bone, with or without the involvement of articular cartilage. The purpose of this compressive review is to give an overview of overuse injuries in sport by describing the theoretical foundations of these conditions that may predispose to the development of tendinopathy, stress fractures, stress reactions, and juvenile osteochondritis dissecans and the implication that these pathologies may have in their management.

CONCLUSIONS

Further research is required to improve our knowledge on tendon and bone healing, enabling specific treatment strategies to be developed for the management of overuse injuries.

Achilles Tendinopathy

Achilles tendinopathy is a common cause of disability. Despite the economic and social relevance of the problem, the causes and mechanisms of Achilles tendinopathy remain unclear. Tendon vascularity, gastrocnemius-soleus dysfunction, age, sex, body weight and height, pes cavus, and lateral ankle instability are considered common intrinsic factors. The essence of Achilles tendinopathy is a failed healing response, with haphazard proliferation of tenocytes, some evidence of degeneration in tendon cells and disruption of collagen fibers, and subsequent increase in noncollagenous matrix. Tendinopathic tendons have an increased rate of matrix remodeling, leading to a mechanically less stable tendon which is more susceptible to damage. The diagnosis of Achilles tendinopathy is mainly based on a careful history and detailed clinical examination. The latter remains the best diagnostic tool. Over the past few years, various new therapeutic options have been proposed for the management of Achilles tendinopathy. Despite the morbidity associated with Achilles tendinopathy, many of the therapeutic options described and in common use are far from scientifically based. New minimally invasive techniques of stripping of neovessels from the Kager's triangle of the tendo Achillis have been described, and seem to allow faster recovery and accelerated return to sports, rather than open surgery. A genetic component has been implicated in tendinopathies of the Achilles tendon, but these studies are still at their infancy.

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.

Comparison of Photobiomodulation and Anti-Inflammatory Drugs on Tissue Repair on Collagenase-Induced Achilles Tendon Inflammation in Rats

BACKGROUND

Tendinopathy is characterized by pain, edema, and structural changes in tendon tissue.

OBJECTIVE

In this animal study we decided to compare the short- and medium-term effects of low-level laser therapy (LLLT), dexamethasone, and diclofenac on inflammation and tendon tissue repair in collagenase-induced tendinitis.

MATERIALS AND METHODS

Two hundred five female Wistar rats were randomly divided into five groups. Animals in the control group were given a saline injection and the experimental groups received a collagenase injection (100 μg/tendon) in the peritendinous Achilles and received no treatment, LLLT (3 J, 810 nm, 100 mW), diclofenac (1.1 mg/kg), or dexamethasone (0.02 mg/kg). Histological analyses were performed at 10 time points up to 60 days (n = 5/group each time point), and included an assessment of the severity of inflammation, collagen fiber content, and organization.

RESULTS

Collagenase injection induced a severe inflammatory reaction with significant reduction in collagen content for 48 h, and disorientation of collagen fibers lasting between 14 and 21 days. Diclofenac and dexamethasone reduced inflammatory signs during the first 2 days, although there was prolongation of the inflammatory phase and slower normalization of tendon quality, particularly in the dexamethasone group. LLLT prevented hemorrhage, reduced inflammation severity, and preserved tendon morphology compared with the other groups.

CONCLUSIONS

LLLT showed a significant superiority over commonly used anti-inflammatory pharmaceutical agents in acute collagenase-induced tendinitis.

Risk factors associated to bilateral rotator cuff tears

INTRODUCTION

Overuse, micro-traumas, and impingement, isolated or combined, are the more common etiological factors for rotator cuff tears. Metabolic disorders (diabetes, adiposity, hypercholesterolemia), hypertension, cigarette smoking and a genetic predisposition are considered risk factors. However, no study has compared the prevalence of these risk factors in subjects with bilateral and monolateral tears.

HYPOTHESIS

Controlateral tears can be observed in patients with symptomatic monolateral rotator cuff lesions, especially in those with comorbidities.

MATERIAL AND METHODS

In patients with symptomatic rotator cuff tear, the controlateral shoulders were evaluated by means of ultrasound imaging. Age, BMI, diabetes, hypercholesterolemia, hypertension, cigarette smoking, work habits were registered. Risk factors in subjects with bilateral tears were compared with those with monolateral lesions.

RESULTS

Of the 180 subjects recruited, 69 had a tear in the controlateral shoulder. Higher age and BMI values, heavy repetitive work and diabetes were significantly prevalent in these patients. At multivariate analysis, these factors were independently related to a higher probability to detect bilateral tears.

DISCUSSION

Metabolic risk factors are more heavily involved in presence of bilateral rotator cuff tears, in comparison to monolateral.

TYPE OF STUDY

Original study.

LEVEL OF PROOF

IV.

Posterior tibial tendinopathy: what are the risk factors?

BACKGROUND

Posterior tibial tendinopathy (PTT) is the most common cause of acquired (progressive) flatfoot deformity in adults. To date, PTT research has mainly focused on management rather than on causal mechanisms. The etiology of PTT is likely to be multifactorial because both intrinsic and extrinsic risk factors have been reported. We sought to critically evaluate reported etiologic factors for PTT and consider the concept of genetic risk factors.

METHODS

A detailed review of the literature published after 1936 was undertaken using English-language medical databases.

RESULTS

No clear consensus exists as to the relative importance of the risk factors reported, and neither has any consideration been given to a possible genetic basis for PTT.

CONCLUSIONS

To date, studies have examined various intrinsic and extrinsic risk factors implicated in the etiology of PTT. The interaction of these factors with an individual's genetic background may provide valuable data and help offer a more complete risk profile for PTT. A properly constructed genetic association study to determine the genetic basis of PTT would provide a novel and alternative approach to understanding this condition.

A Clinical, Biological, and Biomaterials Perspective into Tendon Injuries and Regeneration

Tendon injury is common and debilitating, and it is associated with long-term pain and ineffective healing. It is estimated to afflict 25% of the adult population and is often a career-ending disease in athletes and racehorses. Tendon injury is associated with high morbidity, pain, and long-term suffering for the patient. Due to the low cellularity and vascularity of tendon tissue, once damage has occurred, the repair process is slow and inefficient, resulting in mechanically, structurally, and functionally inferior tissue. Current treatment options focus on pain management, often being palliative and temporary and ending in reduced function. Most treatments available do not address the underlying cause of the disease and, as such, are often ineffective with variable results. The need for an advanced therapeutic that addresses the underlying pathology is evident. Tissue engineering and regenerative medicine is an emerging field that is aimed at stimulating the body's own repair system to produce de novo tissue through the use of factors such as cells, proteins, and genes that are delivered by a biomaterial scaffold. Successful tissue engineering strategies for tendon regeneration should be built on a foundation of understanding of the molecular and cellular composition of healthy compared with damaged tendon, and the inherent differences seen in the tissue after disease. This article presents a comprehensive clinical, biological, and biomaterials insight into tendon tissue engineering and regeneration toward more advanced therapeutics.

Elastin: a possible genetic biomarker for more severe ligament injuries in elite soccer. A pilot study

BACKGROUND

The study of new genetic biomarkers in genes related to connective tissue repair and regeneration may help to identify individuals with greater predisposition to injury, who may benefit from targeted preventive measures, and those who require longer recovery time following a muscle, ligament or tendon injury. The present study investigated whether single nucleotide polymorphisms of the Elastin gene could be related to MCL injury.

METHODS

60 top class football players were studied to identify single nucleotide polymorphisms for the Elastin (ELN) gene using Allelic Discrimination analysis. Each player was followed for 7 seasons, and each MCL injury was noted.

RESULTS

Ligament injury rate, severity and recovery time are related to specific genotypes observed in the elastin gene, especially the ELN-AA (16 MCL) and the ELN-AG (3 MCL). Players with the ELN-GG genotype sustained no MCL injury during the 7 seasons of the study.

CONCLUSIONS

The identification of polymorphisms in the ELN gene may be used as a novel tool to better define an athlete's genotype, and help to plan training and rehabilitation programmes to prevent or minimize MCL ligament injuries, and optimize the therapeutic and rehabilitation process after soft tissue injuries, and manage the workloads during trainings and matches.

Hormones and tendinopathies: the current evidence

BACKGROUND

Tendinopathies negatively affect the quality of life of millions of people, but we still do not know the factors involved in the development of tendon conditions.

SOURCES OF DATA

Published articles in English in PubMed and Google Scholar up to June 2015 about hormonal influence on tendinopathies onset. One hundred and two papers were included following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

AREAS OF AGREEMENT

In vitro and in vivo, tenocytes showed changes in their morphology and in their functional properties according to hormonal imbalances.

AREAS OF CONTROVERSY

Genetic pattern, sex, age and comorbidities can influence the hormonal effect on tendons.

GROWING POINTS

The increasing prevalence of metabolic disorders prompts to investigate the possible connection between metabolic problems and musculoskeletal diseases.

AREAS TIMELY FOR DEVELOPING RESEARCH

The influence of hormones on tendon structure and metabolism needs to be further investigated. If found to be significant, multidisciplinary preventive and therapeutic strategies should then be developed.

Efficacy of platelet-rich plasma injections in pain associated with chronic tendinopathy: A systematic review

BACKGROUND

Chronic tendinopathy has often been a management dilemma for general practitioners. With our understanding of the pathophysiology of tendinopathy evolving, so has our management, with the advent of newer strategies such as topical glycerol trinitrate, extracorporeal shock-wave therapy, as well as platelet-rich plasma (PRP).

AIM

To systematically review the literature regarding PRP therapy in chronic tendinopathy.

DESIGN AND SETTING

The databases used in our search include the Elton B. Stephens Co. (EBSCO) database, Medline, the Cochrane library, Ovid, and Embase (the Excerpta Medica database). A total of 389 articles were reviewed from Feb 2010 to April 2014, for possible inclusion. Of these articles, a total of 9 randomized controlled trials (RCTs) met our inclusion criteria. Only 1 RCT was excluded due to previous surgery in both the trial and control groups.

METHODS

Each article was reviewed independently by 2 authors. Each article was analyzed using the Cochrane Criteria checklist. Where any discrepancy occurred in results, a third independent reviewer was consulted.

RESULTS

Our review found that PRP was most effective in patellar and lateral epicondylar tendinopathy, with both RCTs in the patellar section of our study supporting the use of PRP in pain reduction at 3 and 12 months, whereas 2 of 4 studies in the lateral epicondylar section showed improvements in pain and disability at 6 and 12 months. There was a lack of evidence to support the use of PRP in Achilles and rotator cuff tendinopathy.

CONCLUSIONS

Although the results of this review show promise for the use of PRP in chronic tendinopathy, the analysis highlighted the need for more controlled clinical trials comparing PRP with placebo.

Achilles tendons from decorin- and biglycan-null mouse models have inferior mechanical and structural properties predicted by an image-based empirical damage model

Achilles tendons are a common source of pain and injury, and their pathology may originate from aberrant structure function relationships. Small leucine rich proteoglycans (SLRPs) influence mechanical and structural properties in a tendon-specific manner. However, their roles in the Achilles tendon have not been defined. The objective of this study was to evaluate the mechanical and structural differences observed in mouse Achilles tendons lacking class I SLRPs; either decorin or biglycan. In addition, empirical modeling techniques based on mechanical and image-based measures were employed. Achilles tendons from decorin-null (Dcn(-/-)) and biglycan-null (Bgn(-/-)) C57BL/6 female mice (N=102) were used. Each tendon underwent a dynamic mechanical testing protocol including simultaneous polarized light image capture to evaluate both structural and mechanical properties of each Achilles tendon. An empirical damage model was adapted for application to genetic variation and for use with image based structural properties to predict tendon dynamic mechanical properties. We found that Achilles tendons lacking decorin and biglycan had inferior mechanical and structural properties that were age dependent; and that simple empirical models, based on previously described damage models, were predictive of Achilles tendon dynamic modulus in both decorin- and biglycan-null mice.

Patellar Tendinopathy

Context:

Patellar tendinopathy is a common condition. There are a wide variety of treatment options available, the majority of which are nonoperative. No consensus exists on the optimal method of treatment.

Evidence Acquisition:

PubMed spanning 1962-2014.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

The majority of cases resolve with nonoperative therapy: rest, physical therapy with eccentric exercises, cryotherapy, anti-inflammatories, corticosteroid injections, extracorporeal shockwave therapy, glyceryl trinitrate, platelet-rich plasma injections, and ultrasound-guided sclerosis. Refractory cases may require either open or arthroscopic debridement of the patellar tendon. Corticosteroid injections provide short-term pain relief but increase risk of tendon rupture. Anti-inflammatories and injectable agents have shown mixed results. Surgical treatment is effective in many refractory cases unresponsive to nonoperative modalities.

Conclusion:

Physical therapy with an eccentric exercise program is the mainstay of treatment for patellar tendinopathy. Platelet-rich plasma has demonstrated mixed results; evidence-based recommendations on its efficacy cannot be made. In the event that nonoperative treatment fails, surgical intervention has produced good to excellent outcomes in the majority of patients.

MMP-1 promoter genotype and haplotype association with posterior tibial tendinopathy

PURPOSE

Posterior tibial tendon (PTT) is particularly vulnerable and its insufficiency is recognized as the main cause of adult acquired flatfoot. Some patients have a predisposition without clinically recognized cause, suggesting that individual characteristics play an important role in tendinopathy. The objective of the present study is to investigate the association of -519 (rs1144393) matrix metalloproteinase-1 (MMP-1) polymorphism and the -1607 (rs1799750) and -519 MMP-1 haplotypes and risk of PTT dysfunction.

METHODS

The test group included 50 females who presented PTT dysfunction Grade 2 or 3, and who were submitted to surgical treatment, with histopathological examination of the tendon and magnetic resonance image (MRI) confirming tendinopathy, while the control group was 100 asymptomatic women who present intact PTT at MRI. We analyzed functional polymorphisms MMP-1 and their haplotypes using polymerase chain reaction and restriction fragment length analysis.

RESULTS

There was a significant difference in the presence of the different alleles and genotypes between the control group and test group for the MMP-1 gene (p≤0.01). The G allele of the -519 MMP-1 polymorphism increased susceptibility to degeneration in the PTT tendon and seems to be a genetic risk factor. Global haplotype analysis indicated a significant difference between both groups (p<0.0001). Haplotypes G-2G and A-2G had statistically significant risk effect on PTT insufficiency. G-2G, p<0.001; OR=5.72 (CI, 2.84-11.52) and A-2G p=0.002, OR=3.95 (CI, 1.65-9.44).

CONCLUSION

According to our results, -519 MMP-1 isolated and -1607/-519 MMP-1 haplotypes are associated to tendinopathy in posterior tibial tendon.

BMP4 and FGF3 haplotypes increase the risk of tendinopathy in volleyball athletes

OBJECTIVES

To investigate whether genetic variants can be correlated with tendinopathy in elite male volleyball athletes.

DESIGN

Case-control study.

METHODS

Fifteen single nucleotide polymorphisms within BMP4, FGF3, FGF10, FGFR1 genes were investigated in 138 elite volleyball athletes, aged between 18 and 35 years, who undergo 4-5h of training per day: 52 with tendinopathy and 86 with no history of pain suggestive of tendinopathy in patellar, Achilles, shoulder, and hip abductors tendons. The clinical diagnostic criterion was progressive pain during training, confirmed by magnetic resonance image. Genomic DNA was obtained from saliva samples. Genetic markers were genotyped using TaqMan real-time PCR. Chi-square test compared genotypes and haplotype differences between groups. Multivariate logistic regression analyzed the significance of covariates and incidence of tendinopathy.

RESULTS

Statistical analysis revealed participant age (p=0.005) and years of practice (p=0.004) were risk factors for tendinopathy. A significant association between BMP4 rs2761884 (p=0.03) and tendinopathy was observed. Athletes with a polymorphic genotype have 2.4 times more susceptibility to tendinopathy (OR=2.39; 95%CI=1.10-5.19). Also, association between disease and haplotype TTGGA in BMP4 (p=0.01) was observed. The FGF3 TGGTA haplotype showed a tendency of association with tendinopathy (p=0.05), and so did FGF10 rs900379. FGFR1 showed no association with disease.

CONCLUSIONS

These findings indicate that haplotypes in BMP4 and FGF3 genes may contribute to the tendon disease process in elite volleyball athletes.

Single nucleotide polymorphisms associated with non-contact soft tissue injuries in elite professional soccer players: influence on degree of injury and recovery time

BACKGROUND

The biological mechanisms involved in non-contact musculoskeletal soft tissue injuries (NCMSTI) are poorly understood. Genetic risk factors may be associated with susceptibility to injuries, and may exert marked influence on recovery times.

METHODS

Data on type and degree of injury and recovery time were collected in 73 male professional soccer players (43 White, 11 Black Africans and 19 Hispanics) who suffered total of 242 injuries (203 muscle, 24 ligament, and 15 tendon injuries). One single nucleotide polymorphism (SNPs) in the following genes were analyzed: Elastin (ELN); Titin (TTN); SRY-related HMG-box (SOX15); Insulin-like growth factor 2 (IGF2); Chemokine, CC motif, ligand 2 (CCL2); Collagen type 1 alpha 1(COL1A1); Collagen type 5 alpha 1 (COL5A1), and Tenascin C (TNC).

RESULTS

There was evidence of a statistically significant association between the degree of injury and the IGF2 genotype (P = 0.034). In addition, there was evidence of a statistically significant association between the degree of muscle injury and CCL2 (P = 0.026) Finally, there was evidence of a statistically significant association between ELN and degree of injury (p = 0.009) and recovery time (P = 0.043). There was no evidence of a statistically significant association between any of the genes studied and degree of injury or recovery time for tendon injuries.

CONCLUSION

SNPs in the IGF2, CCL2, and ELN genes may be associated to the degree and recovery time of NCMSTI.

Histomorphologic changes of the long head of the biceps tendon in common shoulder pathologies

PURPOSE

To assess molecular and histologic differences between the proximal (intra-articular) and distal (extra-articular) portions of the long head of the biceps (LHB) tendon in 3 different disease states (biceps instability, tendinosis, and degenerative joint disease [DJD]) compared with a healthy tendon (fresh frozen).

METHODS

We used 32 LHB tendons of patients undergoing tenodesis (mean age, 54.7 ± 10.1 years) and 9 harvested tissue donors. Tendons were divided according to 4 diagnostic groups: (1) biceps instability, (2) tendinosis, (3) DJD, and (4) normal control. After sectioning, tendons were fixed in formalin and stained with H&E and alcian blue for histologic analysis. Measurements of collagen organization by use of polarized light microscopy was then performed, and protein expression for type I and type III collagen, tenascin C, and decorin was determined.

RESULTS

There were no statistical differences found for protein expression of type I or type III collagen, tenascin C, or decorin. The proximal and distal regions of the tendons had statistically significant differences in alcian blue staining, with the proximal portion containing a higher amount of proteoglycan (instability, P = .001; tendinosis, P = .005; DJD, P = .008; control, P = .011). When compared with the nonpathologic control tendons, a significant increase in alcian blue staining for the proximal region was seen in all 3 groups. Total polarized light analysis showed that the distal tendon had a significantly higher intensity (organization) compared with the proximal tendon (P < .001); this was also seen in all of the diagnostic groups (instability, P = .010; tendinosis, P = .013; DJD, P = .07; control, P = .028).

CONCLUSIONS

This study showed a greater degree of degeneration of the proximal (intra-articular) regions of the LHB tendon when compared with the distal regions in all pathologic groups. However, no major differences at the cellular level were found among groups.

CLINICAL RELEVANCE

The pathomechanisms of the various forms of known LHB diagnoses are not yet fully understood and basic science studies may help in understanding their etiology and therefore optimizing treatment options.

Tendinopathy treatment: where is the evidence?

Tendinopathy is a common and debilitating condition that results in significant deficits in performance and prolonged time away from activity. For this reason, much effort has been placed in defining beneficial and cost-effective treatments. This review has outlined the current literature on some of the most widely used therapies for cases of tendinopathy. As such, recommendations remain limited by the evidence available. The variability in both quantity and quality of research into tendinopathy treatments makes it difficult to make definitive treatment recommendations. In general, however, a reasonable first line of treatment for tendinopathy should include a course of NSAIDs and eccentric exercise-based physical therapy. Corticosteroid injections seem to offer excellent short-term pain relief but lack long term efficacy. Alternative injections, such as PRP, have shown short-term efficacy for tendinopathy sufferers; data are lacking to support sclerosing agents and proteinase inhibitors. Operative management seems to offer some benefit in symptomatic relief but carries a higher complication rate than other treatment options and should be reserved only for patients recalcitrant to other more conservative options. Although the inability to make definitive therapeutic recommendations in some instances is discouraging, it is important to note that a lack of high-quality evidence supporting specific treatments does not necessarily imply that they are inherently ineffective. Given the growing prevalence of tendinopathy and the impact it has on the general public, it is more important now than ever to continue the search for the most effective and accessible treatment modalities.

Foot posture and patellar tendon pain among adult volleyball players

OBJECTIVE

We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot.

DESIGN

Observational study.

SETTING

Field-based study among competing athletes.

PARTICIPANTS

Volleyball players competing in the Victorian State League, Australia.

ASSESSMENT OF RISK FACTORS

Patellar tendinopathy (PT) is common in sports involving running and jumping and can severely limit athletes' ability to compete. Several studies have investigated potential etiological factors for the development of PT, but little is known about the association between PT and foot posture.

MAIN OUTCOME MEASURES

Static foot posture index (FPI), patellar tendon pain during single-leg decline squatting, and gray scale ultrasound imaging were measured in 78 recreational to elite volleyball players (48 men and 30 women).

RESULTS

Men with patellar tendon pain were more likely to have a normal foot posture and men without pain were more likely to be pronated according to the FPI (P < 0.05). Women showed no association between FPI and pain or imaging (P > 0.05).

CONCLUSIONS

Men with a normal foot posture were more likely to have PT compared to men with a pronated foot type.

Biological factors in the pathogenesis of rotator cuff tears

Rotator cuff tears are common, and lead to shoulder pain and functional impairment. Despite their frequency and related disability, etiology and pathogenesis are still debated. Multiple factors contribute to tears of the rotator cuff. Extrinsic factors are anatomic variables, such as acromial morphologic characteristics, os acromiale, and acromial spurs that compress the rotator cuff by bony impingement or direct pressure from the surrounding soft tissue. Intrinsic factors arise from the tendon itself, because of tensile overload, aging, microvascular supply, traumatisms, or degeneration. Little information is available from a cellular and molecular point of view. We reviewed the biological factors involved in the pathogenesis of rotator cuff tears. Understanding the mechanism of rotator cuff pathology would facilitate the rationale for therapeutic interventions, by guiding the design, selection, and implementation of treatment strategies such as biologic modulation and preventive measures.

Calcific tendinopathy of the rotator cuff tendons

Calcific tendinopathy (CT) of the tendons of the rotator cuff is common in white populations, with a reported prevalence varying from 2.7% to 22%, mostly affecting women between 30 and 50 years. Although CT shows a strong tendency toward self-healing by spontaneous resorption of the deposits, it does not always follow this typical pattern. The etiopathogenesis of CT is still unknown. Many pathogenetic theories have been proposed, and clinical associations between CT and diabetes and thyroid disorders have been reported. The choice of therapeutic approach should depend on the evolution of the condition.