Tendinopathy Research Articles

The Prevalence of Tear Patterns and Their Effects on Tendon Healing After Arthroscopic Surgery in Patients With Full-Thickness Rotator Cuff Tears.

To achieve successful anatomic rotator cuff repair with minimal tension, both the tear pattern and tear size should be considered. However, little information is available concerning the frequency of tear patterns and their effects on tendon healing. To evaluate the distribution of tear patterns in full-thickness rotator cuff tears and whether these patterns affect tendon healing after arthroscopic repair. Case-control study; Level of evidence, 3. Between 2014 and 2021, patients who underwent arthroscopic surgery for symptomatic full-thickness rotator cuff tears with a minimum 2-year follow-up with postoperative magnetic resonance imaging or ultrasound were retrospectively reviewed. After the debridement of degenerative tendon tissue during arthroscopic surgery, the tear pattern was classified as crescent, U, or anterior or posterior L shaped. Intergroup differences in clinical and radiological characteristics were analyzed. In the subgroup analysis, patients were divided into 2 subgroups: small-to-medium or large-to-massive tears. Among the 1037 patients with a full-thickness rotator cuff tear, the most common tear pattern was crescent shaped (39.6%), followed by posterior L, U, and anterior L shaped (26.0%, 21.4%, and 12.9%, respectively). In the subgroup analysis, 713 patients (68.8%) had small-to-medium tears, while 324 (31.2%) had large-to-massive tears. The proportion of large-to-massive tears was significantly higher for the anterior L-shaped tear pattern than for the other tear patterns (24.8%, 28.8%, 52.2%, and 32.6% for crescent, U, and anterior and posterior L shaped, respectively; P < .001). The anterior L-shaped tear pattern had a significantly higher retear rate than the other tear patterns in small-to-medium tears (7.8%, 13.0%, 28.0%, and 10.6% for crescent, U, and anterior and posterior L shaped, respectively; P < .001). The rate of revision surgery because of a symptomatic retear within 2 years after primary surgery was significantly higher for the anterior L-shaped tear pattern than for the other tear patterns (3.8%, 7.5%, 21.6%, and 0.0% for crescent, U, and anterior and posterior L shaped, respectively; P = .002). The prevalence of tear patterns varied depending on the tear size. In small-to-medium tears, the anterior L-shaped tear pattern had the lowest incidence among the tear patterns; however, it had a significantly higher retear rate. Furthermore, the anterior L-shaped tear pattern had a higher incidence of retears requiring early revision surgery than the other tear patterns.

Achilles tenocytes from diabetic and non diabetic donors exposed to hyperglycemia respond differentially to inflammatory stimuli and stretch.

Diabetes mellitus type 2 (DMT2) promotes Achilles tendon (AS) degeneration and exercise could modulate features of DMT2. Hence, this study investigated whether tenocytes of non DMT2 and DMT2 rats respond differently to normo- (NG) and hyperglycemic (HG) conditions in the presence of tumor necrosis factor (TNF)α or cyclic stretch. AS tenocytes, isolated from DMT2 (fa/fa) or non DMT2 (lean, fa/+) adult Zucker Diabetic Fatty (ZDF) rats, were treated with 10 ng/mL TNFα either under NG or HG conditions (1 g/L vs. 4.5 g/L glucose) and were exposed to cyclic stretch (14%, 0.3 Hz, 48 h). Tenocyte survival, metabolic activity, gene and/or protein expression of tendon extracellular matrix component collagen type 1, alpha smooth muscle actin (αSMA, Acta2), the stress defense enzyme heme oxygenase-1 (Hmox1) as well as suppressors of cytokine signaling (Socs)1 and Socs3 were analyzed. Tenocyte vitality remained high, but metabolic activity was slightly impaired by HG conditions irrespectively of cell origin. Collagen type 1 alpha protein and gene expression was suppressed by TNFα, but only in cells of non DMT2 animals in NG culture medium. Higher amounts of αSMA were visualized in tendons/tenocytes of diabetic rats or those exposed to TNFα. Cyclic stretch caused cell alignment in zero stretch direction. In addition, it led to a significant reduction of cell perimeters, particularly in cells of DMT2 donor rats under HG conditions. Hmox1, Socs1 and Socs3 were induced by HG, but only in tenocytes of diabetic rats (4 h). Stretch induced significantly Hmox1 transcriptional activity under NG conditions and Socs3 under HG conditions especially in tenocytes of DMT2 rats. The response of tenocytes to TNFα and cyclic stretch depends on glucose supply and origin suggesting their irreversible impairment by DMT2.

Coordination of Glucose and Glutamine Metabolism in Tendon is Lost in Aging.

Tendinopathy is an age-associated degenerative disease characterized by a loss in extracellular matrix (ECM). Since glucose and glutamine metabolism is critical to amino acid synthesis and known to be altered in aging, we sought to investigate if age-related changes in metabolism are linked to changes in ECM remodeling. We exposed young and aged tendon explants to various concentrations of glucose and glutamine to observe changes in metabolic processing (enzyme levels, gene expression, etc.) and matrix biosynthesis. Interestingly, we found that glutamine processing is affected by glucose levels, but this effect was lost with aging. ECM synthesis was altered in a protein-dependent manner by increased glucose and glutamine levels in young tendons. However, these changes were not conserved in aged tendons. Overall, our work suggests that glucose and glutamine metabolism is important for ECM homeostasis, and age-related changes in nutrient metabolism could be a key driver of tendon degeneration.

Long Head of Biceps Tendinopathy Is Associated With Age and Cuff Tendinopathy on MRI Obtained for Evaluation of Shoulder Pain.

Shoulder pain-mostly related to rotator cuff tendinopathy-is the most common reason adults seek upper limb specialty care. Tendinopathy of the long head of the biceps may be part of rotator cuff tendinopathy, which most of us develop as we age. Evidence that these processes are related and that both are part of human shoulder senescence could contribute to a reconceptualization of shoulder tendinopathy as a single set of age-related changes, which are often well-accommodated, sometimes misinterpreted as an injury, and associated with notable nonspecific treatment effects, thus meriting caution regarding the potential for overtreatment. This study reviewed a consecutive series of MRI scans ordered for the evaluation of shoulder pain and asked: (1) Is long head of the biceps tendinopathy associated with advancing age? (2) Is long head of the biceps tendinopathy associated with concomitant degeneration of the rotator cuff tendons? Five hundred consecutive radiologist interpretations of MRIs of the shoulder obtained between May 2016 and June 2017 for assessment of shoulder pain in adults at a radiology group that provides approximately 80% of the imaging in all practices in our region were reviewed. Patients with bilateral MRIs had one MRI included at random. Patients with fractures, dislocations, previous surgery, and soft tissue masses seen on MRI were excluded, leaving 406 shoulder MRI interpretations for review. The radiology reports were used to identify the presence and severity of rotator cuff and long head of the biceps tendinopathy. Forty-nine percent (197 of 406) were men with a mean ± SD age of 55 ± 14 years, and 54% (220 of 406) were right shoulders. Multivariable analyses accounting for age and gender evaluated the association of long head of the biceps tendinopathy with age and tendinopathy of the rotator cuff tendons. After controlling for tendinopathy of the other rotator cuff tendons, long head of the biceps tendinopathy was more common with advancing age (OR 1.04 [95% CI 1.02 to 1.06] per year; p < 0.001), meaning the prevalence increases by approximately 4% per year. Among people who were imaged for shoulder pain, everyone 85 years or older had both long head of the biceps and rotator cuff tendinopathy. Any rotator cuff pathophysiology was also notably associated with any long head of the biceps pathophysiology (OR 6.9 [95% CI 2.4 to 20]; p < 0.001). About half (49% [162 of 328]) of long head of the biceps tendons were normal in the presence of any supraspinatus tendinopathy, and 5% (9 of 175) of supraspinatus tendons were normal in the presence of any long head of the biceps tendinopathy. The finding that among people seeking care for shoulder pain, long head of the biceps tendinopathy and rotator cuff tendinopathy occur together and are more common with increasing age (and ubiquitous by the latter half of the ninth decade) suggests that most shoulder pain in adults is associated with expected aging of the shoulder tendons inclusive. In this light, clinicians can guide patients to an understanding of shoulder pain as age-appropriate, safe and sound, and accommodated by a large percentage of people as they age, all of which may be unexpected and counterintuitive. Effective assimilation of this knowledge-which may take time and merits patience-has the potential to both put people at ease and open up possibilities for fewer visits, tests, and treatments addressing tendinopathy, allowing patients to manage on their own (agency) with a set of simple exercises and perhaps occasional use of over-the-counter analgesics. Level III, prognostic study.

Is calcification integral to enthesopathy and tendinopathy rather than a separate disease process?

The pathophysiology of enthesopathy and tendinopathy is mucoid degeneration, which includes chondroid metaplasia. The chondroid metaplasia can be associated with calcification. Inflammation is typically absent unless calcification triggers a self-limited immune response representing acute calcific tendinitis. It is therefore important to address the hypothesis that calcific deposits within various entheses and tendons throughout the body are an inconsequential epiphenomenon of enthesopathy and tendinopathy and do not merit a distinct diagnosis or specific treatment. We searched PubMed, Embase, and Web of Science for studies that address the prevalence of calcium in tendons and entheses with or without symptoms of tendinopathy, specifically excluding likely acute calcific tendinitis, and analyzed 35 studies meeting inclusion and exclusion criteria. Response variables included prevalence of calcification in and enthesis or tendon among people with no symptoms, among people seeking care for symptoms, and in the opposite asymptomatic limb, and the association between calcification and rotator cuff degeneration. Calcification of tendons and entheses was present on between 2.7% and 8.6% of radiographs of the shoulder, elbow, and ankle among people without symptoms and not seeking care, with higher percentages in older populations. Calcification was common among patients with symptoms: 44% for rotator cuff tendinopathy, 25% for enthesopathy of the origin of the extensor carpi radialis brevis, and 53% for medial elbow enthesopathy. Most people with calcification had it bilaterally. Among people with calcification of the rotator cuff on MRI, nearly all of them (96%) had tendon degeneration. The collective evidence regarding calcification in tendons and entheses suggests that it is related to mucoid degeneration and is not a separate disease process. Acute calcific tendinitis rapidly runs its course and is treated only to alleviate symptoms. It's not clear that acute calcific tendinitis or rotator cuff tendinopathy with calcification benefit from specific treatment of the calcium deposits. Not applicable.

Pedrada syndrome and massive degeneration of the Achilles tendon: a case report

Pedrada syndrome and massive degeneration of the Achilles tendon: a case report

Cellular senescence impairs tendon extracellular matrix remodeling in response to mechanical unloading.

Musculoskeletal injuries, including tendinopathies, present a significant clinical burden for aging populations. While the biological drivers of age-related declines in tendon function are poorly understood, it is well accepted that dysregulation of extracellular matrix (ECM) remodeling plays a role in chronic tendon degeneration. Senescent cells, which have been associated with multiple degenerative pathologies in musculoskeletal tissues, secrete a highly pro-inflammatory senescence-associated secretory phenotype (SASP) that has potential to promote ECM breakdown. However, the role of senescent cells in the dysregulation of tendon ECM homeostasis is largely unknown. To assess this directly, we developed an invitro model of induced cellular senescence in murine tendon explants. This novel technique enables us to study the isolated interactions of senescent cells and their native ECM without interference from age-related systemic changes. We document multiple biomarkers of cellular senescence in induced tendon explants including cell cycle arrest, apoptosis resistance, and sustained inflammatory responses. We then utilize this invitro senescence model to compare the ECM remodeling response of young, naturally aged, and induced-senescent tendons to an altered mechanical stimulus. We found that both senescence and aging independently led to alterations in ECM-related gene expression, reductions in protein synthesis, and tissue compositional changes. Furthermore, MMP activity was sustained, thus shifting the remodeling balance of aged and induced-senescent tissues towards degradation over production. Together, this demonstrates that cellular senescence plays a role in the altered mechano-response of aged tendons and likely contributes to poor clinical outcomes in aging populations.

Comparative imaging modalities for diagnosing rotator cuff injuries

Rotator cuff injuries are a significant cause of shoulder pain and dysfunction, with their prevalence increasing with age. Diagnosing these injuries accurately is crucial for determining appropriate treatment strategies. Various imaging modalities, such as high-resolution ultrasonography (HRUS), magnetic resonance imaging (MRI), and magnetic resonance arthrography (MRA), play a pivotal role in identifying rotator cuff injuries. MRI, considered the gold standard, offers detailed insights into tendon degeneration, partial tears, and full-thickness tears. Meanwhile, HRUS is favored for its cost-effectiveness, non-invasive nature, and real-time dynamic assessments. This review compares these imaging techniques, highlighting their diagnostic accuracy, strengths, and limitations in the context of rotator cuff injuries. Although MRI provides comprehensive information on tendon pathology and associated conditions like muscle atrophy, HRUS remains a valuable tool due to its accessibility and accuracy in diagnosing both partial and full-thickness tears. Understanding the comparative efficacy of these imaging modalities is essential for clinicians to make informed decisions about patient management.

Painful accessory navicular syndrome: A modified Kidner procedurenavicular

Objectives Painful accessary navicular syndrome is treated by various surgical methods after failed conservative treatment. The reason for the persisting pain, in all the surgically intervened cases, was degeneration of tibialis posterior tendon due to the need for dissecting the tendon in all the operative techniques described till date. So the surgical intervention for a painful accessary navicular syndrome should be done without disturbing the tibialis posterior tendon. Material and Methods We are presenting a surgical technique modifying the Kidner procedure while avoiding any damage to tibialis posterior tendon and a case series using our technique 11 patients underwent this procedure, of which ten were available for at least a two-year follow-up. Results The American orthopaedic foot and ankle society (AOFAS) ankle-hind foot score improved from 70 to 95 in the three-month follow-up and maintained till the final follow-up. Conclusion This modified Kidner procedure could be an effective technique in preventing persisting pain following the surgical treatment of the painful accessory navicular syndrome.

Focal Versus Combined Focal Plus Radial Extracorporeal Shockwave Therapy in Lateral Elbow Tendinopathy: A Retrospective Study.

Background: Lateral epicondylitis of the elbow, commonly known as tennis elbow, is a musculoskeletal disorder characterized by pain and degeneration of the common extensor tendon. Despite various treatments, optimal management remains debated. Objective: This study aimed to compare the effectiveness of focal extracorporeal shockwave therapy (F-ESWT) alone versus a combination of focal and radial pressure waves (F-ESWT+R-PW) in treating chronic lateral epicondylitis. Methods: This retrospective observational study included 45 patients diagnosed with chronic lateral epicondylitis divided into two groups based on the treatment received: group A (F-ESWT, n = 23) and group B (F-ESWT+R-PW, n = 22). Both groups underwent three weekly sessions of their respective treatments. Patients were also given a home exercise protocol. Primary outcomes were assessed using the Visual Analog Scale (VAS) for pain and the Patient-Rated Tennis Elbow Evaluation (PRTEE) for pain and functional impairment at baseline (T0), 4 weeks (T1), 12 weeks (T2), and 24 weeks (T3) post-treatment. Secondary outcomes included grip strength and ultrasonographic measurements of common extensor tendon (CET) thickness and vascularization. Results: Significant improvements in VAS and PRTEE scores were observed in both groups at all follow-up points. Group B showed greater pain reduction at T1 (VAS: 3.0 ± 1.6 vs. 4.43 ± 1.47; p < 0.005) and T2 (VAS: p < 0.030) compared to group A. Functional outcomes (PRTEE) also favored group B at T1 (p < 0.030) and in the pain section at T2 (p < 0.020). Grip strength improved similarly in both groups. CET thickness showed no significant differences at T3. Vascularization decreased significantly in both groups, with a non-significant trend favoring group B. Conclusions: The combined F-ESWT+R-PW therapy proved more effective than F-ESWT alone in the short- to mid-term management of chronic lateral epicondylitis, significantly enhancing pain reduction and functional outcomes. The combination of focal and radial pressure waves offers a superior therapeutic approach, leveraging the distinct mechanisms of each modality for better clinical results. Further research is needed to confirm these findings and establish long-term efficacy.

THE INFLUENCE OF THE CULTURE OF FIBROBLASTIC CELL ELEMENTS ON THE INDICATORS OF THE METABOLISM OF CONNECTIVE TISSUE IN EXPERIMENTAL ANIMALS

The number of patients with degenerative tendon disease affects millions of people both among athletes and the general population, causing significant socio-economic consequences. Despite the availability of various methods of conservative and surgical treatment, more than a third of patients experience constant pain. Objective. To study the indicators of the metabolism of connective tissue in animals with a model of degenerative damage to tendons against the background of the introduction of a culture of fibroblastic cell elements. Methods. Therefore, the development of methods for restoring the structure of tendons using cell cultures, in particular fibroblasts, will allow to optimize the course of reparative processes, reduce the risk of complications during surgical intervention and accelerate healing, and at the molecular level — to improve the structure of collagen fibers. Laboratory studies of biochemical markers of a tendon with a degenerative-dystrophic lesion and against the background of the introduction of cell culture can help in the differential diagnosis of its extracellular matrix. Results. The experimental data obtained by us indicate the presence of differences in the biochemical markers of tendons with degenerative-dystrophic lesions in rats 7, 21, and 45 days after the introduction of culture of fibroblastic cell elements. However, 45 days after the introduction of the culture of fibroblast cell elements, the normalization of metabolic processes in the extracellular matrix of connective tissue occurs, namely, the activity of collagenase and the concentration of protein-bound hydroxyproline approaches normal values. This indicates the predominance of the synthetic phase over the catabolic one in collagen metabolism. Conclusions. In this context, the introduction of culture of fibroblastic cell elements, as an alternative anti-inflammatory method, may provide another potential opportunity in the treatment of chronic degenerative-dystrophic lesions of the Achilles tendon.

Dose Severity of Achilles Tendinopathy on Preoperative MRI Predict Functional Outcomes after Minimally Invasive Zadek Osteotomy?

Category: Hindfoot; Ankle Introduction/Purpose: Minimally Invasive Zadek osteotomy (MIS ZO) has been demonstrated to be a safe and effective surgical intervention for patients with Insertional Achilles Tendinopathy (IAT) and Haglund’s deformity. However, there is limited literature to guide surgeons one which patients may be the best candidates for MIS ZO. Severity of IAT on preoperative MRI may correlate with post operative functional outcomes and help guide patient selection for treatment with MIS ZO. The current study evaluated the postoperative outcomes of MIS ZO in patients with various grades of Achilles tendinopathy on preoperative MRI, to determine if severity of disease on preoperative MRI could be predictive of improved functional outcomes after MIS ZO. Methods: Patients who underwent MIS ZO for IAT and Haglund’s deformity were identified and retrospectively analyzed at a mean of 15.59 months follow-up. Achilles pathology was graded as previously described by Nicholson et al. on preoperative MRI. Grade 1 describes anteroposterior diameter of 6-8 mm and nonuniform degeneration; grade 2 describes diameter &gt;8 mm and &lt; 50% uniform tendon degeneration; grade 3 describes tendon diameter &gt;8 mm and uniform degeneration of &gt;50% tendon width. Fourteen patients met our inclusion criteria. Four patients exhibited grade 1 pathology preoperatively, 3 patients exhibited grade 2 pathology preoperatively, and 7 patients exhibited grade 3 pathology preoperatively. Preoperative and postoperative Patient Reported Outcome Measurement Information System (PROMIS) scores, complications, and revisions were recorded for each patient. PROMIS scores were compared using a paired t-test. All other continuous data was compared by Analysis of Variance (ANOVA); all categorical data was compared using Chi-squared analysis. P&lt; 0.05 were considered significant. Results: PROMIS pain score improved postoperatively in patients with grade 1 66.75±5.50 to 59.00±7.75, p=0.036) and grade 3 (69.86±6.17 to 55.71±10.44, p=0.011) Achilles tendinopathy on preoperative MRI. Meanwhile, in patients with grade 2 pathology, PROMIS physical function (38.33±8.50 to 43.67±9.07, p=0.02) improved postoperatively. In the grade three group, 1/7 (14.29%) patients experienced transient neuritis that resolved at 3 months without further treatment and 1/7 (14.29%) patients required revision surgery to an open midline splitting Haglund’s resection. Meanwhile no patients in either the grade one or grade two groups required reoperation, rehospitalization, or complications. 13/14 (93%) patients were very satisfied with their procedure and wound undergo it again. Conclusion: These early data suggest that patients with IAT, regardless of severity, improve after MIS ZO. Therefore, ZO may be a reasonable first line option for all patients presenting with IAT. In our small retrospective study, we were able to demonstrate significant improvement in pain and/or function following ZO in all grades of IAT tendinous pathology on preoperative MRI. This study may help guide surgeons when deciding between MIS ZO and other surgical options for IAT and Haglund’s deformity. Further, large prospective studies are warranted to further investigate outcomes and indications of MIS ZO in patients with IAT and Haglund’s deformity

Identification of age-related genes in rotator cuff tendon.

Rotator cuff tear (RCT) is the leading cause of shoulder pain, primarily associated with age-related tendon degeneration. This study aimed to elucidate the potential differential gene expressions in tendons across different age groups, and to investigate their roles in tendon degeneration. Linear regression and differential expression (DE) analyses were performed on two transcriptome profiling datasets of torn supraspinatus tendons to identify age-related genes. Subsequent functional analyses were conducted on these candidate genes to explore their potential roles in tendon ageing. Additionally, a secondary DE analysis was performed on candidate genes by comparing their expressions between lesioned and normal tendons to explore their correlations with RCTs. We identified 49 genes in torn supraspinatus tendons associated with advancing age. Among them, five age-related genes showed DE in lesioned tendons compared to normal tendons. Functional analyses and previous studies have highlighted their specific enrichments in biological functions, such as muscle development (e.g. myosin heavy chain 3 (MYH3)), transcription regulation (e.g. CCAAT enhancer binding brotein delta (CEBPD)), and metal ion homeostasis (e.g. metallothionein 1X (MT1X)). This study uncovered molecular aspects of tendon ageing and their potential links to RCT development, offering insights for targeted interventions. These findings enhance our understanding of the mechanisms of tendon degeneration, allowing potential strategies to be made for reducing the incidence of RCT.

Outcomes After Extracorporeal Shockwave Therapy for Chronic Noninsertional Achilles Tendinopathy Compared With Chronic Insertional Achilles Tendinopathy: A Retrospective Review.

Extracorporeal shockwave therapy (ESWT) is a noninvasive treatment modality that is used in the treatment of chronic Achilles tendinopathy (AT). To (1) retrospectively assess outcomes after ESWT for both noninsertional AT (NAT) and insertional AT (IAT) at >1-year follow-up and (2) identify potential predictors of outcomes. Cohort study; Level of evidence, 3. Chart review was conducted to identify patients who underwent ESWT for AT with a minimum of 1-year follow-up. Data collected and assessed included patient demographic characteristics, pathological characteristics including the location of AT (NAT or IAT), presence of a Haglund deformity, and severity of tendon degeneration on magnetic resonance imaging (MRI), in addition to treatment characteristics including number of sessions and intensity of ESWT. The Victorian Institute of Sports Assessment-Achilles (VISA-A) and visual analog scale (VAS) pain scores were obtained before ESWT, 6 months after ESWT, and at final follow-up. Failures were also recorded, which were defined as no improvement in VISA-A or VAS scores or need for surgical intervention. Linear regression was performed to identify potential predictors of inferior subjective clinical outcomes and failures. Survival analysis was conducted using Kaplan-Meier curves. The study included 52 patients with IAT and 34 patients with NAT. The mean follow-up in the NAT cohort was 22.3 ± 10.2 months and the mean follow-up in the IAT cohort was 26.8 ± 15.8 months. Improvements in VISA-A and VAS scores were observed in the NAT cohort at 6-month follow-up and at final follow-up (P < .05). Improvements in VISA-A and VAS scores were recorded in the IAT cohort at 6-month follow-up, which subsequently deteriorated at final follow-up. In the NAT cohort, the failure rate at 6-month follow-up was 11.8%, which increased to 29.4% at final follow-up. In the IAT cohort, the failure rate at 6-month follow-up was 32.7%, which increased to 59.6% at final follow-up. Predictors of inferior subjective clinical outcomes and failures in the NAT cohort included pre-ESWT subjective clinical score, male sex, presence of a cardiovascular risk factor, and more severe MRI grading of tendinopathy. Predictors of inferior subjective clinical outcomes and failures in the IAT cohort included pre-ESWT subjective clinical score and more severe MRI grading of tendinopathy. Superior subjective clinical outcomes together with a lower failure rate were maintained for >1 year in the NAT cohort compared with the IAT cohort, calling into question the long-term benefit of ESWT for patients with IAT.

Pre-operative gluteus medius tendon degeneration and its impact on strength and functional ability one year after total hip replacement

Objective Hip osteoarthritis is a common cause of disability and surgery is often unavoidable. Patient satisfaction is high and functional ability improves after surgery. However, residual impairment and pain are common. Degenerative changes in tendons and muscles are probable causes. The aim of this study is to investigate gluteus medius (GMED) tendon degeneration in relation to muscle strength, physical function and walking distance before and one year after total hip replacement. Material and methods In total, 18 patients were examined pre- and post-operatively, of whom 15 were available in the final analysis. Muscle strength, physical function and walking distance were assessed. Tendon biopsies were assessed microscopically, and the total degeneration score (TDS) was calculated. Results A correlation between the TDS and muscle strength was found for the hamstrings, GMED and quadriceps pre- or post-operatively. No correlations were found between the TDS and functional ability. Functional ability and muscle strength improved significantly after surgery. Conclusion Our results indicate a correlation between tendon degeneration and the muscle strength of the hip and knee in patients with hip OA and one year after THR. To minimise post-operative residual discomfort, rehabilitation programs should probably be modified over time to match the pre- and post-operative needs. Further studies are needed. This study was registered at https://www.researchweb.org/is/vgr/project/279039 (in Swedish).

The Biological Effect of Platelet-Rich Plasma on Rotator Cuff Tears: A Prospective Randomized In Vivo Study.

The positive effect of platelet-rich plasma (PRP) on tendon metabolism has been extensively investigated and proven in vitro. Additionally, in vivo animal studies have correlated the application of PRP with the enhancement of tenocyte anabolic activity in the setting of tendon degeneration. However, less is known about its in vivo effect on human tendon biology. The purpose of the current prospective randomized comparative study was to evaluate the effect of PRP on torn human supraspinatus tendon. Twenty consecutive eligible patients with painful and magnetic resonance imaging (MRI)-confirmed degenerative supraspinatus tendon tears were randomized in a one-to-one ratio into two groups. The patients in the experimental group (n = 10) underwent an ultrasound-guided autologous PRP injection in the subacromial space 6 weeks before the scheduled operation. In the control group (n = 10), no injection was made prior to surgery. Supraspinatus tendon specimens were harvested from the lateral end of the torn tendon during shoulder arthroscopy and were evaluated under optical and electron microscopy. In the control group, a mixed cell population of oval and rounded tenocytes within disorganized collagen and sites of accumulated inflammatory cells was detected. In contrast, the experimental group yielded abundant oval-shaped cells with multiple cytoplasmic processes within mainly parallel collagen fibers and less marked inflammation, simulating the intact tendon structure. These findings indicate that PRP can induce microscopic changes in the ruptured tendon by stimulating the healing process and can facilitate a more effective recovery.

The Efficacy of Intratissue Percutaneous Electrolysis (EPI®) and Nutritional Factors for the Treatment of Induced Tendinopathy in Wistar Rats: Hepatic Intermediary Metabolism Effects.

Achilles tendinopathy (TP) is characterized as the third most common disease of the musculoskeletal system, and occurs in three phases. There is currently no evidence of effective treatment for this medical condition. In this study, the modulatory effects of the minimally invasive technique intratissue percutaneous electrolysis (EPI) and combinations of EPI with four nutritional factors included in the diet, hydroxytyrosol (HT), maslinic acid (MA), glycine, and aspartate (AA), on hepatic intermediary metabolism was examined in Wistar rats with induced tendinopathy at various stages of TP. Results obtained showed that induced tendinopathy produced alterations in the liver intermediary metabolisms of the rats. Regarding carbohydrate metabolism, a reduction in the activity of pro-inflammatory enzymes in the later stages of TP was observed following treatment with EPI alone. Among the combined treatments using nutritional factors with EPI, HT+EPI and AA+EPI had the greatest effect on reducing inflammation in the late stages of TP. In terms of lipid metabolism, the HT+EPI and AA+EPI groups showed a decrease in lipogenesis. In protein metabolism, the HT+EPI group more effectively reduced the inflammatory effects of induced TP. Treatment with EPI combined with nutritional factors might help regulate intermediary metabolism in TP disease and reduce the inflammation process.

Platelet-derived exosomes alleviate tendon stem/progenitor cell senescence and ferroptosis by regulating AMPK/Nrf2/GPX4 signaling and improve tendon-bone junction regeneration in rats

BackgroundTendon stem/progenitor cell (TSPC) senescence contributes to tendon degeneration and impaired tendon repair, resulting in age-related tendon disorders. Ferroptosis, a unique iron-dependent form of programmed cell death, might participate in the process of senescence. However, whether ferroptosis plays a role in TSPC senescence and tendon regeneration remains unclear. Recent studies reported that Platelet-derived exosomes (PL-Exos) might provide significant advantages in musculoskeletal regeneration and inflammation regulation. The effects and mechanism of PL-Exos on TSPC senescence and tendon regeneration are worthy of further study.MethodsHerein, we examined the role of ferroptosis in the pathogenesis of TSPC senescence. PL-Exos were isolated and determined by TEM, particle size analysis, western blot and mass spectrometry identification. We investigated the function and underlying mechanisms of PL-Exos in TSPC senescence and ferroptosis via western blot, real-time quantitative polymerase chain reaction, and immunofluorescence analysis in vitro. Tendon regeneration was evaluated by HE staining, Safranin-O staining, and biomechanical tests in a rotator cuff tear model in rats.ResultsWe discovered that ferroptosis was involved in senescent TSPCs. Furthermore, PL-Exos mitigated the aging phenotypes and ferroptosis of TSPCs induced by t-BHP and preserved their proliferation and tenogenic capacity. The in vivo animal results indicated that PL-Exos improved tendon-bone healing properties and mechanical strength. Mechanistically, PL-Exos activated AMPK phosphorylation and the downstream nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPX4) signaling pathway, leading to the suppression of lipid peroxidation. AMPK inhibition or GPX4 inhibition blocked the protective effect of PL-Exos against t-BHP-induced ferroptosis and senescence.ConclusionIn conclusion, ferroptosis might play a crucial role in TSPC aging. AMPK/Nrf2/GPX4 activation by PL-Exos was found to inhibit ferroptosis, consequently leading to the suppression of senescence in TSPCs. Our results provided new theoretical evidence for the potential application of PL-Exos to restrain tendon degeneration and promote tendon regeneration.

An EDucation and eXercise intervention for gluteal tendinopathy in an Irish setting: a protocol for a feasibility randomised clinical trial (LEAP-Ireland RCT).

Gluteal tendinopathy (GT) is a degenerative tendon condition characterised by pain over the greater trochanter of the hip. A randomised controlled trial (RCT) in Australia found that 14 sessions of EDucation on load management plus eXercise (EDX) delivered over 8 weeks resulted in greater improvements in global rating of change and pain outcomes at 8 and 52 weeks, compared with corticosteroid injection or 'wait and see'. Typically, 5-6 physiotherapy sessions are provided in public and private physiotherapy settings in Ireland, therefore, the aim of this study is to examine the feasibility of conducting a future definitive RCT to investigate effectiveness of 6 sessions of the EDX programme compared to usual care. We will randomly allocate 64 participants with GT to physiotherapist-administered EDX or usual care. The EDX intervention (EDX-Ireland) will be delivered in 6 sessions over 8 weeks.To determine feasibility of an RCT, we will assess recruitment and retention and outcome measure completion. The health status outcomes to be assessed at baseline, 8 weeks and 3 months include: Global Rating of Change, pain severity, the Victorian Institute of Sport Assessment-Gluteal Questionnaire (VISA-G), the Patient-Specific Functional Scale, the Pain Catastrophizing Scale, Patient Health Questionnaire (PHQ), Pain Self-Efficacy Questionnaire, the EQ-5D-5L, the Central Sensitisation Inventory and hip abductor muscle strength. We will explore acceptability of the EDX-Ireland intervention from the perspective of patients and treatment providers, and the perspective of referrers to the trial. A Study Within A Trial will be also applied to compare recording of exercise adherence using app-based technology to paper diaries. There is a need to establish effective treatments for GT that potentially can be implemented into existing health systems. The findings of this feasibility trial will inform development of a future definitive RCT. The trial is registered prospectively on ClinicalTrials.gov ( NCT05516563, 27/10/2022).

ASSOCIATION BETWEEN WEIGHTBEARING CT AND MRI FINDINGS IN PROGRESSIVE COLLAPSING FOOT DEFORMITY

BackgroundWeightbearing computed tomography scans allow for better understanding of foot alignment in patients with Progressive Collapsing Foot Deformity. However, soft tissue integrity cannot be assessed via WBCT. As performing both WBCT and magnetic resonance imaging is not cost effective, we aimed to assess whether there is an association between specific WBCT and MRI findings.MethodsA cohort of 24 patients of various stages of PCFD (mean age 51±18 years) underwent WBCT scans and MRI. In addition to signs of sinus tarsi impingement, four three-dimensional measurements (talo-calcaneal overlap, talo-navicular coverage, Meary's angle axial/lateral) were obtained using a post processing software (DISIOR 2.1, Finland) on the WBCT datasets. Sinus tarsi obliteration, spring ligament complex and tibiospring ligament integrity, as well as tibialis posterior tendon degeneration were evaluated with MRI. Statistical analysis was performed for significant (P&lt;0.05) correlation between findings.ResultsNone of the assessed 3D measurements correlated with spring ligament complex or tibiospring ligament tears. Age, body mass index, and TCO were associated with tibialis posterior tendon tears. 75% of patients with sinus tarsi impingement on WBCT also showed signs of sinus tarsi obliteration on MRI. Of the assessed parameters, only age and BMI were associated with sinus tarsi obliteration diagnosed on MRI, while the assessed WBCT based 3D measurements were, with the exception of MA axial, associated with sinus tarsi impingement.ConclusionWhile WBCT reflects foot alignment and indicates signs of osseous impingement in PCFD patients, the association between WBCT based 3D measurements and ligament or tendon tears in MRI is limited. Partial or complete tears of the tibialis posterior tendon were only detectable in comparably older and overweight PCFD patients with an increased TCO. WBCT does not replace MRI in diagnostic value. Both imaging options add important information and may impact decision-making in the treatment of PCFD patients.