TRIM54 alleviates inflammation and apoptosis by stabilizing YOD1 in rat tendon-derived stem cells.

Tendinopathy is a disorder of musculoskeletal system that primarily affects athletes and the elderly. Current treatment options are generally comprised of various exercise and loading programs, therapeutic modalities, and surgical interventions and are limited to pain management. This study is to understand the role of TRIM54 (tripartite motif containing 54) in tendonitis through in vitro modeling with tendon-derived stem cells (TDSCs) and in vivo using rat tendon injury model. Initially, we observed that TRIM54 overexpression in TDSCs model increased stemness and decreased apoptosis. Additionally, it rescued cells from tumor necrosis factor α-induced inflammation, migration, and tenogenic differentiation. Further, through immunoprecipitation studies, we identified that TRIM54 regulates inflammation in TDSCs by binding to and ubiquitinating YOD1. Further, overexpression of TRIM54 improved the histopathological score of tendon injury as well as the failure load, stiffness, and young modulus in vivo. These results indicated that TRIM54 played a critical role in reducing the effects of tendon injury. Consequently, these results shed light on potential therapeutic alternatives for treating tendinopathy.

Nonoperative or Surgical Treatment of Acute Achilles' Tendon Rupture.

BACKGROUND: Whether surgical repair of an acute Achilles' tendon rupture by an open-repair or minimally invasive approach is associated with better outcomes than nonsurgical treatment is not clear. METHODS: We performed a multicenter, randomized, controlled trial that compared nonoperative treatment, open repair, and minimally invasive surgery in adults with acute Achilles' tendon rupture who presented to four trial centers. The primary outcome was the change from baseline in the Achilles' tendon Total Rupture Score (scores range from 0 to 100, with higher scores indicating better health status) at 12 months. Secondary outcomes included the incidence of tendon rerupture. RESULTS: A total of 554 patients underwent randomization, and 526 patients were included in the final analysis. The mean changes in the Achilles' tendon Total Rupture Score were -17.0 points in the nonoperative group, -16.0 points in the open-repair group, and -14.7 points in the minimally invasive surgery group (P = 0.57). Pairwise comparisons provided no evidence of differences between the groups. The changes from baseline in physical performance and patient-reported physical function were similar in the three groups. The number of tendon reruptures was higher in the nonoperative group (6.2%) than in the open-repair or minimally invasive surgery group (0.6% in each). There were 9 nerve injuries in the minimally invasive surgery group (in 5.2% of the patients) as compared with 5 in the open-repair group (in 2.8%) and 1 in the nonoperative group (in 0.6%). CONCLUSIONS: In patients with Achilles' tendon rupture, surgery (open repair or minimally invasive surgery) was not associated with better outcomes than nonoperative treatment at 12 months. (Funded by the South-Eastern Norway Regional Health Authority and Akershus University Hospital; ClinicalTrials.gov number, NCT01785264.).

Spontaneous tendon or ligament ruptures in patients undergoing dialysis: First pediatric case report and literature review.

Spontaneous tendon or ligament ruptures are quite rare and mostly associated with chronic systemic diseases such as diabetes mellitus, systemic lupus erythematosus, rheumatoid arthritis, and chronic kidney disease (CKD). In this study, we present the first documented case of a spontaneous rupture of the medial patellofemoral ligament (MPFL) in a pediatric patient. The patient was undergoing long-term peritoneal dialysis (PD) and had a history of severe secondary hyperparathyroidism. Additionally, we discussed spontaneous tendon and ligament ruptures associated with CKD or dialysis through a comprehensive literature review. This case report highlights the importance of recognizing that spontaneous tendon or ligament injuries are not exclusive to adults; children with CKD can also be affected. Several factors including poor parathyroid hormone (PTH) and metabolic acidosis control, prolonged CKD duration and presence of malnutrition play role in the pathogenesis. Early diagnosis is crucial as it allows for timely surgical intervention and leads to a favorable functional recovery.

Endothelial cells-derived exosomes-based hydrogel improved tendinous repair via anti-inflammatory and tissue regeneration-promoting properties.

Tendon injuries are common orthopedic ailments with a challenging healing trajectory, especially in cases like the Achilles tendon afflictions. The healing trajectory of tendon injuries is often suboptimal, leading to scar formation and functional impairment due to the inherent low metabolic activity and vascularization of tendon tissue. As pressing is needed for effective interventions, efforts are made to explore biomaterials to augment tendon healing. However, tissue engineering approaches face hurdles in optimizing tissue scaffolds and nanomedical strategies. To navigate these challenges, an injectable hydrogel amalgamated with human umbilical vein endothelial cells-derived exosomes (HUVECs-Exos) was prepared and named H-Exos-gel in this study, aiming to enhance tendon repair. In our research involving a model of Achilles tendon injuries in 60 rats, we investigated the efficacy of H-Exos-gel through histological assessments performed at 2 and 4 weeks and behavioral assessments conducted at the 4-week mark revealed its ability to enhance the Achilles tendon's mechanical strength, regulate inflammation and facilitate tendon regeneration and functional recovery. Mechanically, the H-Exos-gel modulated the cellular behaviors of macrophages and tendon-derived stem cells (TDSCs) by inhibiting inflammation-related pathways and promoting proliferation-related pathways. Our findings delineate that the H-Exos-gel epitomizes a viable bioactive medium for tendon healing, heralding a promising avenue for the clinical amelioration of tendon injuries.

Early Predictors of Recovery From Nonoperatively Treated Achilles Tendon Rupture: 1 Year Follow-Up Study.

PURPOSE: To investigate early structural and mechanical predictors of plantarflexor muscle strength and the magnitude of Achilles tendon (AT) nonuniform displacement at 6 and 12 months after AT rupture. METHODS: Thirty-five participants (28 males and 7 females; mean ± SD age 41.7 ± 11.1 years) were assessed for isometric plantarflexion maximal voluntary contraction (MVC) and AT nonuniformity at 6 and 12 months after rupture. Structural and mechanical AT and plantarflexor muscle properties were measured at 2 months. Limb asymmetry index (LSI) was calculated for all variables. Multiple linear regression was used with the 6 and 12 month MVC LSI and 12 month AT nonuniformity LSI as dependent variables and AT and plantarflexor muscle properties at 2 months as independent variables. The level of pre- and post-injury sports participation was inquired using Tegner score at 2 and 12 months (scale 0-10, 10 = best possible score). Subjective perception of recovery was assessed with Achilles tendon total rupture score (ATRS) at 12 months (scale 0-100, 100=best possible score). RESULTS: Achilles tendon resting angle (ATRA) symmetry at 2 months predicted MVC symmetry at 6 and 12 months after rupture (ß = 2.530, 95% CI 1.041-4.018, adjusted R2 = 0.416, p = 0.002; ß = 1.659, 95% CI 0.330-2.988, adjusted R2 = 0.418, p = 0.016, respectively). At 12 months, participants had recovered their pre-injury level of sports participation (Tegner 6 ± 2 points). The median (IQR) ATRS score was 92 (7) points at 12 months. CONCLUSION: Greater asymmetry of ATRA in the early recovery phase may be a predictor of plantarflexor muscle strength deficits up to 1 year after rupture. TRIAL REGISTRATION: This research is a part of "nonoperative treatment of Achilles tendon rupture in Central Finland: a prospective cohort study" that has been registered in ClinicalTrials.gov (NCT03704532).

Effect of a single versus serial platelet-rich plasma injection on the healing of acute patellar tendon defect: an experimental study.

BACKGROUND: There is no consensus on the frequency and timing of platelet-rich plasma (PRP) injection in tendon healing. We aimed to evaluate the effectiveness of single versus multiple PRP injections in the healing of patellar tendon defects in the experimental model, through histological and biomechanical investigation. METHODS: Forty-four male skeletally mature Dutch rabbits were randomly divided into the five study groups ( A, B,C, D,E). After creating a longitudinal acute patellar tendon defect on both knees (One-third the width of the patella tendon), the right legs of the rabbits were used as the intervention group and the left legs as the control groups. Animals in groups A, B, and C were euthanized on days 7, 14, and 28, respectively, after the first PRP injection. Animals in group D received the second PRP injection on day 10 and was euthanized on day 14. Animals in group D received the second and third PRP injections on days 10 and 20, respectively, and were euthanized on day 28. The outcomes were evaluated histologically (modification of Movin's Grading) and biomechanically. RESULTS: The inflammatory condition was exaggerated in groups D and E. Load at failure was higher in the non-injected side of groups D and E, while there was no significant difference between the right and left legs of the three groups A, B and C. In other word, groups with a single PRP injection were more resistant to the increasing load compared to the groups with multiple PRP injections. CONCLUSIONS: PRP improves tendon healing if injected early after injury, while its injection after the initial phase of injury hampers tendon healing. In addition, a single PRP injection seems to be more effective than multiple PRP injection. Therefore, in cases where PRP injection is indicated for tendon repair, such as acute tendon injury, we recommend using a single PRP injection during tendon repair surgery.

Effectiveness of a novel finger range-of-motion brace for extensor tendon injury: a report of 10 patients.

BACKGROUND: Extensor tendon injuries require surgical repair, followed by rehabilitation to ensure optimal outcomes. Immobilization has been the cornerstone of postoperative management. However, immobilization after surgery frequently makes the finger stiffness, often resulting in reduced functionality and quality of life for patients. Recent studies indicate that early controlled motion can significantly improve outcomes, but safe early range of motion (ROM) exercise is a significant clinical challenge. This article aims to check the efficacy of the novel designed finger ROM brace for preventing finger stiffness for extensor tendon injuries with case series. METHODS: A finger ROM brace was designed based on the natural finger movement. Like a real finger, there are two tiny hinge joints and three round-shape body components. The design aimed to be ergonomic dynamic splint assisting controlled motion to promote early motion, thus reducing tendon tension and preventing stiffness. Elastic resistant ROM exercise could be by inserting a silicone band into the groove on the components and free movement could be achieved by removing a silicone band. RESULT: Between December 2022 and July 2023, 10 patients who underwent tenorrhaphy because of extensor tendon laceration were involved. Complete extensor tendon laceration was 3 patients, other seven patients had partial laceration of extensor tendons. Surgery was performed within 2 days of injury, and no infection was observed in all patients. After the extensor tendon was confirmed as healed state by ultrasound, the patients were permit the active exercise wearing finger ROM brace with a silicone band. Within 1-2 weeks after elastic resistant exercise, the patients could achieve free full ROM movement without any complication. CONCLUSION: The novel finger ROM brace combines the advantages of dynamic splinting and under-actuated mechanisms to offer a comprehensive solution for preventing stiffness after extensor tendon suture. Future studies should focus on clinical trials to validate the efficacy and safety of this brace in a larger population.

Investigation of the effects of treatment with enoxaparin sodium and hyperbaric oxygen therapy on the recovery of rats with achilles tendon rupture.

PURPOSE: In this study, we aimed to investigate the effects of hyperbaric oxygen therapy and enoxaparin sodium, which are known to accelerate bone tissue healing as well as tendon and soft tissue healing, on the healing of Achilles tendon rupture. METHODS: Thirty-six rats were used in the present study. All rats were divided into groups of nine. The groups were the enoxaparin sodium group, enoxaparin sodium and hyperbaric oxygen group, hyperbaric oxygen group and control group. After 21 days, the process was completed, and the rats were sacrificed. Achilles tendon samples were evaluated histopathologically. RESULTS: The groups were compared according to the results of statistical analysis based on the histopathological data. There was no significant difference between the groups in terms of acute inflammation (p = 0.785) or chronic inflammation (p = 0.827) scores, but there were significant differences in neovascularization (p = 0.009), proliferation (p < 0.001) and fibrosis (p = 0.006) scores. CONCLUSION: Our study showed that the use of enoxaparin sodium and hyperbaric oxygen had a positive effect on the healing of the Achilles tendon. Based on these results, we believe that the use of enoxaparin sodium and hyperbaric oxygen therapy after Achilles tendon rupture will be beneficial for healing and preventing complications.

Considerations for the care of transgender patients in orthopaedics and sports medicine: a narrative review.

Orthopaedic and sports medicine clinicians can improve outcomes for transgender patients by understanding the physiological effects of gender-affirming hormone therapy (GAHT). This narrative review investigated the role of GAHT on bone mineral density, fracture risk, thromboembolic risk, cardiovascular health and ligament/tendon injury in this population. A search from the PubMed database using relevant terms was performed. Studies were included if they were levels 1-3 evidence. Due to the paucity of studies on ligament and tendon injury risk in transgender patients, levels 1-3 evidence on the effects of sex hormones in cisgender patients as well as basic science studies were included for these two topics. This review found that transgender patients on GAHT have an elevated fracture risk, but GAHT has beneficial effects on bone mineral density in transgender women. Transgender women on GAHT also have an increased risk of venous thromboembolism, stroke and myocardial infarction compared with cisgender women. Despite these elevated risks, studies have found it is safe to continue GAHT perioperatively for both transgender women and men undergoing low-risk operations. Orthopaedic and sports medicine clinicians should understand these unique health considerations for equitable patient care.

Photobiomodulation and amniotic membrane for treat tendon injury in rats.

Tendons, complex fibrous structures, are subjected to great tensions, which can give rise to the so-called tendinopathies. This study aimed to evaluate photobiomodulation and human Amniotic Membrane applied as single or combined therapies to treat induced Achilles tendon lesions. Seventy-five rats were divided into five groups (n=15): C- control Sham surgery; I- tendon injury; LA- tendon injury treated with photobiomodulation; AM- tendon injury treated with Amniotic Membrane; LAM- tendon injury + photobiomodulation and Amniotic Membrane, subdivided into three groups (n=5) with analysis at 3, 7, and 14 days. The tendon injuries were made with a 20 g weight released from a mini guillotine onto the ankle in dorsiflexion. AM and LAM groups received an Amniotic Membrane fragment while LA and LAM groups received transcutaneous photobiomodulation, using a 660 nm wavelength laser. The inflammatory cells showed statistical differences between groups C and I (p<0.05), I and AM (p<0.01), I and LA (p<0.05), and I and LAM (p<0.01). Both photobiomodulation and Amniotic Membrane were shown to enhance tendon repair, and the association of photobiomodulation plus Amniotic Membrane was the most effective treatment. We conclude that the association of photobiomodulation plus Amniotic Membrane was effective in accelerating and improving the tendon regeneration process.

Effect of cell therapy with adipose-derived stem cells in the treatment of acute rupture of the Achilles tendon in humans.

The aim of this study was to evaluate the effect of adipose-derived stem cells (ADSCs) in the treatment of acute rupture of the Achilles tendon. It was a cross-sectional study involving 15 patients. Patients were randomly divided: group 1-rupture; group 2-suture; group 3-rupture + ADSCs. In the AOFAS score, the score was higher in group 3 with a significant difference. In the ATRS score, the score was higher in groups 2 and 3, also with a significant difference. As for the ultrasound score, there was a significant difference between the experimental groups in relation to this score, however, in the multiple comparisons test, comparing two groups at a time, it was possible to observe a significant difference of the experimental groups. It can be concluded that cell therapy in this condition may be a treatment option due to tissue regeneration and significant recovery of function.

Recent Advances in the Use of Stem Cells in Tissue Engineering and Adjunct Therapies for Tendon Reconstruction and Future Perspectives.

Due to their function, tendons are exposed to acute injuries. This type of damage to the musculoskeletal system represents a challenge for clinicians when natural regeneration and treatment methods do not produce the expected results. Currently, treatment is long and associated with long-term complications. In this review, we discuss the use of stem cells in the treatment of tendons, including how to induce appropriate cell differentiation based on gene therapy, growth factors, tissue engineering, proteins involved in regenerative process, drugs and three-dimensional (3D) structures. A multidirectional approach as well as the incorporation of novel components of the therapy will improve the techniques used and benefit patients with tendon injuries in the future.

Regional variations in incidence and treatment trends of Achilles tendon ruptures in Finland: a nationwide study.

BACKGROUND AND PURPOSE: The aim of our study was to assess the regional variations in Achilles tendon rupture incidence and treatment methods in Finland during the period 1997-2019. METHODS: The Finnish National Hospital Discharge Register (NHDR) and the Finnish Register of Primary Health Care Visits (PHCR) were searched to identify all adult patients diagnosed with Achilles tendon rupture during our study period. The population-based annual incidence and incidences of surgically and non-surgically treated Achilles tendon ruptures were calculated for each hospital district. RESULTS: Achilles tendon rupture incidence increased from 17.3 per 105 person-years in 1997 to 32.3 per 105 in 2019. The mean incidence of Achilles tendon ruptures ranged from 26.4 per 105 (North Savo) to 37.2 per 105 (Central Ostrobothnia). The incidence of Achilles tendon ruptures increased in all areas. The proportion of non-surgical treatment of Achilles tendon ruptures ranged in 1997 from 7% (Vaasa) to 67% (Åland) and in 2019 from 73% (Southwest Finland) to 100% (East Savo, Kainuu, Länsi-Pohja, Åland). During the study period, a shift towards non-surgical treatment was evident in all hospital districts. CONCLUSION: Regional variations in Achilles tendon rupture incidence exist in Finland; however, the incidence increased in all areas during the follow-up period. More Achilles tendon rupture patients are currently being treated non-surgically throughout the country.

Return to Play and Functional Outcomes Following Treatment of Acute Achilles Tendon Ruptures: A Systematic Review and Meta-Analysis.

Return to play (RTP) and functional outcomes are critical to treatment success for acute Achilles tendon rupture (AATR). This systematic review and meta-analysis explored treatment superiority essential in optimal treatment selection concerning individual patients and their expectations regarding RTP and functional outcomes. This study was in accordance with the preferred reporting items for systematic reviews and meta-analyses guidelines. The included studies were assessed regarding the level and quality of evidence. Fixed-effects models were employed for I2 < 25% and random-effects models for I2 ≥ 25%. The RTP rate meta-analysis of surgical vs conservative treatment revealed no significant difference. This was similar to the subgroup analysis of open repair and conservative treatment. The RTP rate and Achilles Tendon Total Rupture Score (ATRS) meta-analysis of open repair + earlier rehabilitation (ER) vs + later rehabilitation (LR) also revealed no significant differences. The mean time to RTP meta-analysis of open repair + ER vs + LR showed that open repair + ER was significantly favored (-4.19 weeks; p = .002). The ATRS meta-analysis of conservative treatment with ER vs with LR revealed no significant difference. This meta-analysis has revealed that the RTP rates following treatment of AATR are high. Therefore, the decision for surgical vs conservative treatment or open repair + ER vs + LR for AATR should not be selected based on the expectation of RTP. However, open repair + ER can be advocated over + LR for reduced mean time to RTP.

Audit of a Revised Pathway Aimed at Expediting Diagnosis and Treatment for Suspected Achilles Tendon Rupture.

Treatment outcomes for Achilles tendon ruptures depend upon prompt diagnosis and management. A local study in 2018 highlighted inefficiencies in patient management, and a revised protocol was introduced allowing investigation and referral to be initiated by other healthcare professionals. This retrospective audit evaluates the impact of this on the timescale from presentation to treatment. It analyzes all suspected Achilles tendon ruptures within one District General Hospital from April 2021 to March 2022. Data regarding patient timelines was compared to the 2018 study. Over 12 months, 99 patients were referred to Virtual Fracture Clinic, 87.8% (n = 87) of which had a complete or partial tear on ultrasound scan (USS). In comparison to 2018, the average time from presentation to USS request reduced from 2.9 to 1.1 days (p < .01). 95% were scanned within one week of USS request and 31.3% within 48 hours (81% and 18%, previously). The average time from USS request to scan went from 6.8 to 3.2 days (p < .01). The time from presentation to treatment decision reduced from 10.9 to 6.2 days (p < .01) and the percentage of patients with a definitive treatment plan within one week increased from 34.5% to 74.2% (p < .01). Patients required 0.8 fewer appointments (p < .01) giving an estimated total saving of $10,110 ($128 per patient) during the analyzed period. The Achilles Tendon Rupture Pathway has significantly improved the proportion of patients undergoing USS within 48 hours and receiving a treatment decision within one week. This study demonstrates an efficient, cost-saving and replicable pathway for Achilles tendon ruptures.

Gluteus Maximus Distal Myotendinous Junction Tear in a Pickleball Player: A Case Report.

ABSTRACT: A 72-year-old male presented for evaluation of a 2-wk history left buttock pain that began while playing pickleball. He sustained a left inversion ankle sprain while in a squatted position and landed on his left buttock. Four days after his injury, he developed extensive bruising involving his lower back, buttock, and left thigh. On examination, he had tenderness to palpation at the left side of the sacrum and in the region of the deep external rotators. Left hip range of motion was full in extension but limited to 90° of flexion, which reproduced left-sided buttock pain. External rotation provoked pain, but internal rotation was full and pain free. MRI of the pelvis demonstrated a grade 2 partial thickness tear of the left gluteus maximus muscle at its distal myotendinous junction with associated retraction and intramuscular hematoma. He was managed with compression with biking shorts, icing, acetaminophen, and physical therapy. He returned to pickleball approximately 4 wk after his injury, and at his 4-wk follow-up, he reported 99% improvement in his symptoms with the only remaining complaint being minimal discomfort with gluteal stretching.

Analysis of Punch Injuries: Clinical Characteristics, Management and Outcomes.

PURPOSE OF THE STUDY: The aim of this study is to describe injury patterns, characteristics, treatment modalities and functional outcomes after punching related injuries. MATERIAL AND METHODS: Retrospective data of cases admitted to emergency department following punch injury between January 1, 2012, and December 31, 2022. was collected. Patient's demographic data, the dominant and injured upper extremity side, punched object, a time of patient admission were recorded. Smoking habit and blood ethanol level were documented. Trauma mechanism, diagnosis (1: dermabrasions: skin, 2: lacerations: neurovascular structures or tendons and 3: osseous pathologies), treatment modalities were analyzed. Outcomes were assessed using the DASH questionnaire (Disabilities of the Arm, Shoulder, and Hand) at the last follow-up. RESULTS: A total of 1052 patients (male=968 (92%), female=84 (8%)) with mean age 24.6 ± 7.2 included this study. Six hundred and twenty-one (59%) patients punched a solid object and 675 (64%) had osseous pathology. The most commonly fractured bone, injured tendon, injured nerve, and injured artery were 5th metacarpal, extensor digitorum communis (EDC), ulnar nerve, and ulnar artery, respectively. The majority of the patients, (73%) were smokers while 15% of the patients had high level of blood ethanol concentration on admission (82±12.3 mg/100 ml). A comparison between smokers and non-smokers did not reveal any significant differences (p=0.425) in terms of diagnosis whereas 74% of alcoholic patients admitted with lacerations which was statistically significant (p=0.023). Injuries of 321 (30.5%) patients required surgery in the operating room, while 711(67.5 %) patients received interventions in the emergency room setting. The average DASH score differed between subgroups, with significantly higher scores in patients with laceration type injuries (7.2 SD), indicating more disability (p=0.001) DISCUSSION. The study reveales a high prevalence of hand injuries among individuals aged 18 to 40, with the dominant hand being most affected, primarily due to physical violence and self-harming behaviors. Primary contributing factors to this pattern are the escalated incidents of physical violence and self-harming behaviors arising from an inability to manage anger impulses. Punching solid objects, especially during late afternoon and evening periods often associated with alcohol use, was a common cause, resulting in metacarpal fractures being the most reported injury. Multiple tendon and nerve injuries were frequent, highlighting the severity and complexity of these traumas, often necessitating surgical intervention. CONCLUSIONS: These findings highlight the several key aspects, including demographic characteristics of the patient population, common causes and types of injuries observed, and the association between alcohol use as well as the specific injury profiles. Satisfactory results can be achieved with both conservative and surgical treatment for punch injuries. KEY WORDS: punching, fisting, boxing injuries, laceration, blood ethanol level.

[Long head of the biceps pathologies : diagnosis and treatments]. / Diagnostics et traitements des pathologies du long chef du biceps.

The long head of the biceps (LHB) tendon is a common source of shoulder pain. Often associated with other injuries, the tendon can alone be responsible of the symptoms. Spontaneous rupture has been observed to allow for pain relief. The spectrum of LHB lesions is broad. Repetitive motion, carrying heavy loads, have been associated with diagnosis. Specific tests have been described to diagnose biceps injuries, their implementation can remain difficult in the presence of associated pathologies. The combination of a history and clinical examination with the use of targeted imaging is required to establish the diagnosis. The management of bicipital pathologies is frequently carried out following main surgical procedures. Isolated management of biceps lesions can provide a satisfactory result when a comprehensive procedure cannot be performed.

Le tendon du long chef du biceps (LCB) est une source fréquente de douleurs à l'épaule. Souvent associé à d'autres atteintes, il peut être seul responsable de la symptomatologie et sa rupture peut apporter un soulagement « salvateur ¼. Le spectre des lésions du LCB est large. Les mouvements répétés de lancer, tirer ou le port de charges ont été associés à une atteinte du LCB. De nombreux examens spécifiques ont été développés afin de diagnostiquer ces lésions. Leur réalisation peut rester un défi clinique en cas de pathologies associées. Une anamnèse, un examen clinique ainsi qu'une imagerie ciblée sont requis pour établir le diagnostic. La prise en charge de ces lésions est souvent réalisée durant des procédures chirurgicales principales. Leur prise en charge isolée permet un résultat fonctionnel satisfaisant lorsqu'un geste exhaustif ne peut être réalisé.

Matrix stiffness-mediated tenogenesis of tendon stem/progenitor cells via integrin-αm for tendon regeneration.

Tendon injuries, commonly associated with sports activities, pose significant challenges in terms of treatment and recovery due to limited tendon regeneration and the formation of proliferative scars. Stem cell-based therapy has shown promising application, but there are still challenges. Physical and biological cues are instrumental in guiding stem cell differentiation and maturation. This study focuses on exploring the effects of matrix biomechanics on tendon stem/progenitor cells (TSPCs) differentiation. We fabricated polydimethylsiloxane (PDMS) substrates with different elastic modulus to mimic the mechanical characteristics of healthy tendons. A tissue-engineered culture system was developed for tenogenesis, and pre-differentiated tissue-engineered tendons were transplanted in vivo to assess their efficacy in regenerating patella tendon injuries. Furthermore, we demonstrated that the biomechanical stimuli activated the integrin-αm to enhance the tenogenesis capacity of TSPCs. Our findings highlight the importance of biomechanics in tendon tissue engineering and provide a novel perspective for enhancing tendon regeneration.

Cerium oxide nanoparticles-carrying human umbilical cord mesenchymal stem cells counteract oxidative damage and facilitate tendon regeneration.

BACKGROUND: Tendon injuries have a high incidence and limited treatment options. Stem cell transplantation is essential for several medical conditions like tendon injuries. However, high local concentrations of reactive oxygen species (ROS) inhibit the activity of transplanted stem cells and hinder tendon repair. Cerium oxide nanoparticles (CeONPs) have emerged as antioxidant agents with reproducible reducibility. RESULTS: In this study, we synthesized polyethylene glycol-packed CeONPs (PEG-CeONPs), which were loaded into the human umbilical cord mesenchymal stem cells (hUCMSCs) to counteract oxidative damage. H2O2 treatment was performed to evaluate the ROS scavenging ability of PEG-CeONPs in hUCMSCs. A rat model of patellar tendon defect was established to assess the effect of PEG-CeONPs-carrying hUCMSCs in vivo. The results showed that PEG-CeONPs exhibited excellent antioxidant activity both inside and outside the hUCMSCs. PEG-CeONPs protect hUCMSCs from senescence and apoptosis under excessive oxidative stress. Transplantation of hUCMSCs loaded with PEG-CeONPs reduced ROS levels in the tendon injury area and facilitated tendon healing. Mechanistically, NFκB activator tumor necrosis factor α and MAPK activator dehydrocrenatine, reversed the therapeutic effect of PEG-CeONPs in hUCMSCs, indicating that PEG-CeONPs act by inhibiting the NFκB and MAPK signaling pathways. CONCLUSIONS: The carriage of the metal antioxidant oxidase PEG-CeONPs maintained the ability of hUCMSCs in the injured area, reduced the ROS levels in the microenvironment, and facilitated tendon regeneration. The data presented herein provide a novel therapeutic strategy for tendon healing and new insights into the use of stem cells for disease treatment.