Tendon Repair Research Articles

The impact of diabetes mellitus on tendon pathology: a review

Diabetes is one of the most common metabolic diseases worldwide, leading to complications, mortality, and significant healthcare expenditures, which impose a substantial social and financial burden globally. A diabetic environment can induce metabolic changes, negatively affecting tendon homeostasis, leading to alterations in biomechanical properties and histopathology. Numerous studies have investigated the mechanisms through which diabetes exerts pathological effects on tendons, including increased free radical production, oxidative stress, inflammatory responses, deposition of advanced glycation end products (AGEs), and microvascular changes. These metabolic changes damages tendon structure, biomechanics, and tendon repair processes. The proliferation of tendon stem cells decreases, apoptosis increases, and abnormal differentiation, along with abnormal expression of myofibroblasts, ultimately lead to insufficient tendon repair, fibrosis, and remodeling. Although researches unveiling the effects of diabetes on tendinopathy, fibrosis or contracture, and tendon injury healing are growing, systematic understanding is still lacking. Therefore, this review summarizes the current research status and provides a comprehensive overview, offering theoretical guidance for future in-depth exploration of the impact of diabetes on tendons and the development of treatments for diabetes-related tendon diseases.

Self-assembling peptide hydrogel scaffold accelerates healing of patellar tendon injury: A histological and biomechanical study.

Although KI24RGDS peptide hydrogel that acts as a cell adhesion has been reported to repair tissue in meniscus injury, its effect on tendon injuries remains unknown. The purpose of this study was to clarify the effect of KI24RGDS for tendon repair based on histological and biomechanical evaluation. After introducing defects (length: 10mm; width: 3mm) at the centers of rabbits' patellar tendons, and the KI24RGDS group was implanted with KI24RGDS and observed for 8 weeks. KI24RGDS implantation resulted in limited tendon elongation and better histological scores with uniformed collagen fiber orientation and early vascularization. The failure load of the patellar tendon was higher in the KI24RGDS group than that in the defect group (p < 0.05) and no significant difference with the control group (intact patellar tendon) at 8weeks postoperatively. In conclusion, KI24RGDS administration might have therapeutic potential for tendon injuries by accelerating collagen remodeling.

Advancements in Therapeutic Approaches for Degenerative Tendinopathy: Evaluating Efficacy and Challenges

Degenerative tendinopathy results from the accumulation of minor injuries following unsuccessful tendon repair during acute tendon injuries. The process of tendon repair is prolonged and varies between individuals, making it susceptible to reinjury. Moreover, treating chronic tendinopathy often requires expensive and extensive rehabilitation, along with a variety of combined therapies to facilitate recovery. This condition significantly affects the quality of life of affected individuals, underscoring the urgent need for more efficient and cost-effective treatment options. Although traditional treatments have improved significantly and are being used as substitutes for surgical interventions, the findings have been inconsistent and conflicting. This review aims to clarify these issues by exploring the strengths and limitations of current treatments as well as recent innovations in managing various forms of degenerative tendinopathy.

Fabrication of MnO2-Modified Decellularized Tendon Membrane for Enhancing Tendon Repair.

Repairing tendon/ligament injuries is a major challenge in sports medicine. It has been reported that tendon injury healing is hindered by massive production of reactive oxygen species (ROS). Manganese oxides nanoparticles are generally non-toxic, can scavenge ROS, promote tissue regeneration, and hold promise for sustainable nanotechnologies. However, the effective and safe integration of MnO2 nanoparticles on decellularized scaffold mediating tissue repair is still a great challenge. To address these issues, an in situ MnO2-modified decellularized scaffold is developed to enhance tendon regeneration through improving microenvironment. The decellularized fibrous membrane is designed and prepared using the central tendon of the porcine diaphragm. Then MnO2 nanozymes are in situ grown on the collagen fibers using tannic acid (TA) as cross-linking agent and reducing agent. The results showed that MnO2-modified scaffold eliminates excessive accumulation of ROS in cells, protects mitochondrial, and maintains the phenotype of tendon cells in an oxidative stress environment. Notably, it is found that the MnO2-modified scaffold exhibits good biocompatibility and is able to promote the tendon healing in the rat patellar tendon defect model. Altogether, this study confirmed that this nanozyme-functionalized decellularized extracellular matrix effectively enhanced tendon repair by scavenging ROS, which provides new strategies for enhancing tendon regeneration.

A study on the effect of platelet-rich plasma (PRP) to promote bone fusion in lateral interbody fusion of the lumbar spine using artificial bone

BackgroundLateral lumbar interbody fusion (LLIF) via a retroperitoneum approach has gained popularity due to minimal invasiveness, which avoids resection of the spinous process and laminae. However, as challenges in grafting autogenous bone persist, artificial bone has been tested in Japan to fill the spinal cage. Platelet-rich plasma (PRP) contains growth factors and anti-inflammatory cytokines to promote cellular proliferation and repair damaged tissues. While the effects of PRP on tendon and ligament repair are widely known, any effects on bone healing are scarcely reported. However, PRP-loaded artificial bone carries potential to improve intervertebral bone fusion.ObjectiveThis study assessed whether PRP enhances intervertebral bone fusion in LLIF surgery using β-tricalcium phosphate artificial bone.MethodsThe current study was a prospective, randomized, controlled trial. We evaluated 13 consecutive patients undergoing LLIF surgery in our hospital. Patients received artificial bone impregnated with PRP or without PRP within the same fusion cage. The primary outcome was the intervertebral bone fusion rate at 6 and 12 months postoperatively, evaluated using CT imaging. The intervertebral bone fusion rates with and without PRP loading and with and without contact part between the endplate and the artificial bone were compared. Secondary outcomes included clinical evaluations using visual analog scale scores for low back pain, buttock-leg pain, and leg numbness from the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOA-BPEQ) and the Oswestry Disability Index (ODI), plus adverse events information.ResultsOf the 13 patients (29 vertebral segments) included, bone fusion was observed in 43.4% of the PRP group and 26.1% of the non-PRP group at 6 months (p = 0.216). At 12 months, fusion rates were 60.9% with PRP and 34.8% without PRP (p = 0.074). The fusion rate was significantly higher in cases with good contact between the vertebral endplate and the artificial bone (p = 0.0004). Clinical scores improved postoperatively. Adverse events were in accordance with expectations from LLIF surgery and no PRP-specific events occurred.ConclusionPRP did not significantly improve intervertebral bone fusion rates in LLIF surgeries, particularly in cases with poor contact between the vertebral endplate and artificial bone. While PRP may have a limited role in enhancing bone fusion, maintaining good contact between the vertebral endplate and artificial bone is crucial for successful outcomes. Further research is needed to explore optimal uses of PRP in spinal fusion surgeries.

Comparison of a novel side-to-side tenorrhaphy with Pulvertaft weave: an in vitro biomechanical study

PurposeThe aim of this study was to characterize the biomechanical properties of a novel side-to-side tenorrhaphy (SST), this tenorrhaphy is designed to achieve reliable strength utilizing fewer knots and greater operationalization. This is compared with a well-established tendon reconstruction technique called the Pulvertaft weave technique (PWT).MethodsTwenty fresh porcine hindfoot flexor tendons were collected, and 10 novel SST and 10 PWT were performed in each group. The repaired tendons were tested cyclically by applying a force of 35 N using an electric tensile testing machine. Tendons were loaded until they ruptured and failed. The cyclic elongation, ultimate elongation, ultimate failure load, stiffness, and operation time were recorded and analyzed for both groups, and the failure patterns of the tendons were observed.ResultsThe mean operation time were 1.86 in the SST group and 3.25 min for the PWT group, respectively. The ultimate failure load was 179.93 N ± 12.05 for the SST group and 113.46 N ± 7.89 for the PWT group. The ultimate elongation was 17.79 mm ± 0.51 for the SST group and 26.83 mm ± 0.64 for the PWT group. The stiffness of the SST group was 35.27 N/mm ± 0.90 in the SST group and 20.11 N/mm ± 0.84 in the PWT group. There was no statistically significant difference in cyclic elongation.ConclusionThe SST group performed better than the PWT group in terms of the ultimate elongation, ultimate failure load, and stiffness. It is clear that the novel SST is a reliable alternative to PWT for tendon repair. The operation time of the SST group was significantly shorter than that of the PWT group.

Single-nucleus transcriptional and chromatin accessibility analyses of maturing mouse Achilles tendon uncover the molecular landscape of tendon stem/progenitor cells.

Tendons and ligaments are crucial connective tissues linking bones and muscles, yet achieving full functional recovery after injury remains challenging. We investigated the characteristics of tendon stem/progenitor cells (TSPCs) by focusing on the declining tendon repair capacity with growth. Using single-cell RNA sequencing on Achilles tendon cells from 2- and 6-week-old mice, we identified Cd55 and Cd248 as novel surface antigen markers for TSPCs. Combining single-nucleus ATAC and RNA sequencing analyses revealed that Cd55 and Cd248 positive fractions in tendon tissue are TSPCs, with this population decreasing at 1 weeks. We also identified candidate upstream transcription factors regulating these fractions. Functional analyses of isolated CD55/CD248 positive cells demonstrated high clonogenic potential and tendon differentiation capacity, forming functional tendon-like tissue in vitro . This study establishes CD55 and CD248 as novel TSPC surface antigens, potentially advancing tendon regenerative medicine and contributing to the development of new treatment strategies for tendon and ligament injuries.

Two-Stage Flexor Tendon Reconstruction for Finger Contracture Secondary to Phlegmon: A Case Report

Flexor tendon reconstruction is a complex surgical procedure that requires great precision and specialized expertise. It remains a preferred treatment for patients with neglected lacerations of the digital flexor tendon and after the failure of flexor tendon repair. Improvements in tendon repair methods and follow-up techniques have enhanced outcomes after flexor tendon grafting. Case Presentation: A 14-year-old girl with a history of a phlegmon of the 4th finger of the right hand, treated with antibiotics and drainage. The evolution is marked after 2 years by the progressive development of a flexion contracture of the proximal interphalangeal (PIP) joint. On examination, there is a flexion attitude and an inability to extend the PIP joint without vascular or nervous disorders. A two-stage reconstruction was performed using the palmaris longus tendon as a graft. With a follow-up of 3 years, the girl has recovered complete flexion and has limited extension to 25° at the PIP joint. An arthrolysis was proposed, but the girl refused, and she is satisfied with the results.

Controlled TPCA-1 delivery engineers a pro-tenogenic niche to initiate tendon regeneration by targeting IKKβ/NF-κB signaling

Tendon repair remains challenging due to its poor intrinsic healing capacity, and stem cell therapy has emerged as a promising strategy to promote tendon regeneration. Nevertheless, the inflammatory environment following acute tendon injuries disrupts stem cell differentiation, leading to unsatisfied outcomes. Our study recognized the critical role of NF-κB signaling in activating inflammation and suppressing tenogenic differentiation of stem cells after acute tendon injury via multiomics analysis. TPCA-1, a selective inhibitor of IKKβ/NF-κB signaling, efficiently restored the impaired tenogenesis of stem cells in the inflammatory environment. By developing a microsphere-incorporated hydrogel system for stem cell delivery and controlled release of TPCA-1, we successfully engineered a pro-tenogenic niche to initiate tenogenesis for tendon regeneration. Collectively, we recognize NF-κB signaling as a critical target to tailor a pro-tenogenic niche and propose the combined delivery of stem cells and TPCA-1 as a potential strategy for acute tendon injuries.

Clinical and Radiologic Evaluation of Mucopolygen Complex on Patients Who Underwent Arthroscopic Full Thickness Supraspinatus Tendon Repair

Clinical and Radiologic Evaluation of Mucopolygen Complex on Patients Who Underwent Arthroscopic Full Thickness Supraspinatus Tendon Repair

Orthopedic revolution: The emerging role of nanotechnology.

This review summarizes the latest progress in orthopedic nanotechnology, explores innovative applications of nanofibers in tendon repair, and evaluates the potential of selenium and cerium oxide nanoparticles in osteoarthritis and osteoblast differentiation. This review also describes the emerging applications of injectable hydrogels in cartilage engineering, emphasizing the critical role of interdisciplinary research and highlighting the challenges and future prospects of integrating nanotechnology into orthopedic clinical practice. This comprehensive approach provides a holistic perspective on the transformative impact of nanotechnology in orthopedics, offering valuable insights for future research and clinical applications.

Transcriptome-Optimized Hydrogel Design of a Stem Cell Niche for Enhanced Tendon Regeneration.

Bioactive hydrogels have emerged as promising artificial niches for enhancing stem cell-mediated tendon repair. However, a substantial knowledge gap remains regarding the optimal combination of niche features for targeted cellular responses, which often leads to lengthy development cycles and uncontrolled healing outcomes. To address this critical gap, an innovative, data-driven materiomics strategy is developed. This approach is based on in-house RNA-seq data that integrates bioinformatics and mathematical modeling, which is a significant departure from traditional trial-and-error methods. It aims to provide both mechanistic insights and quantitative assessments and predictions of the tenogenic effects of adipose-derived stem cells induced by systematically modulated features of a tendon-mimetic hydrogel (TenoGel). The knowledge generated has enabled a rational approach for TenoGel design, addressing key considerations, such as tendon extracellular matrix concentration, uniaxial tensile loading, and in vitro pre-conditioning duration. Remarkably, our optimized TenoGel demonstrated robust tenogenesis in vitro and facilitated tendon regeneration while preventing undesired ectopic ossification in a rat tendon injury model. These findings shed light on the importance of tailoring hydrogel features for efficient tendon repair. They also highlight the tremendous potential of the innovative materiomics strategy as a powerful predictive and assessment tool in biomaterial development for regenerative medicine.

Vascularised and Non-Vascularised Adipofascial Flap Applications in Tissue Trauma with Tendon Injury, Flap Viability and Tendon Healing a Hystological and Scintigraphical Rat Model Study.

Background and Objectives: Complex wounds in the hand and distal lower extremities pose challenges in reconstructive surgery, often involving critical structures like tendons. Tendon injuries, prevalent in such wounds, necessitate optimal repair methods for functional recovery. This study investigates the impact of vascularised and nonvascularised adipofascial tissue on tendon repair, focusing on early healing stages, mobilisation, and scintigraphic evaluation of flap vascularity. Materials and Methods: Wistar Albino rats were divided into groups undergoing primary tendon repair, vascularised adipofascial flap application, or nonvascularised flap application. Scintigraphic evaluation and histopathological assessment were performed to analyse healing processes. Results: Pedicle-free flaps support healing in tendon injuries without negatively affecting medium-term outcomes. Vascularised flaps exhibit faster healing. The scintigraphic analysis showed that the static measurements of the late phase were statistically significantly higher in the group with the non-vascularised adipofascial flap (p = 0.038). The mean perfusion reserve was higher in the vascularised pedicled adipofascial flap group than the non-vascularised adipofascial flap group. Scintigraphic analysis highlights the viability of pedicle-free flaps. Conclusions: Pedicle-free adipofascial flaps support the healing of the tendon without complicating the results, while vascularised flaps show accelerated healing. These findings provide valuable insights into optimising tendon repair strategies using adipofascial flaps, with implications for enhancing functional recovery in complex wounds.

A Retrospective Study of Lateral Antebrachial Cutaneous Nerve Neuropathy: Electrodiagnostic Findings and Etiologies in 49 Cases.

The lateral antebrachial cutaneous nerve (LACN) is the terminal sensory branch of the musculocutaneous nerve and is rarely entrapped or injured. This study describes the electrodiagnostic (EDX) findings and etiologies of LACN neuropathy. This is a review of 49 patients with pain and/or paresthesia of the forearm who underwent EDX studies. The diagnosis of LACN neuropathy was based on clinical and sensory conduction abnormalities. The most common etiology of LACN neuropathy was iatrogenic injury in 30 (61.2%) patients, primarily due to biceps tendon repair at the elbow (11 [36.7%]) and phlebotomy (5 [16.7%]). Fifteen (30.6%) patients sustained a non-iatrogenic injury at the proximal forearm/elbow, consisting of six (60%) laceration injuries and five (33.3%) stretch injuries. Four (8.2%) patients comprised the "other" etiology category, including two mass lesions causing LACN compression. Pain, paresthesia, and/or numbness in the LACN distribution were reported in 33 (67.3%), 27 (55.1%), and 23 (46.9%) patients, respectively. Hypoesthesia was detected in 45 (91.8%) patients, and dysesthesia in 7 (14.3%). The sensory nerve action potentials (SNAPs) of the LACN on the symptomatic side were absent in 44 (89.8%) patients. Of the five patients whose SNAPs of the LACN were detected, all had a decreased amplitude, and two had increased sensory latency. The most common etiology for LACN neuropathy in this series was iatrogenic injury; repair of biceps tendon at the elbow was the most frequent provoking cause. Protection of the LACN during surgical procedures at the elbow and forearm is vital to prevent iatrogenic injury.

Passive Mobilization With Place-and-Hold Versus Active Mobilization Therapy After Flexor Tendon Repair: 5-Year Minimum Follow-Up of a Randomized Controlled Trial

There is no consensus on the optimal postoperative rehabilitation program following flexor tendon repair. Some studies suggest a faster recovery after active mobilization, whereas other studies have failed to find any differences between active and passive mobilization at 12 months. To our knowledge, no prior randomized controlled trial has compared the long-term effects of these two approaches. This randomized controlled trial compared the long-term outcomes of active mobilization with those of passive mobilization in combination with place-and-hold. Sixty-four patients with a flexor tendon injury in zones I or II were included in the study. After surgery, patients were randomized to either active mobilization or passive mobilization with place-and-hold. Forty-seven patients were available for the 5-year minimum follow-up. Assessments included range of motion, grip strength, key pinch, as well as the Disabilities of the Arm, Shoulder, and Hand (DASH) and ABILHAND questionnaires. At the 5-year minimum follow-up, range of motion was significantly better in the group treated with passive mobilization with place-and-hold compared with the active mobilization group. Furthermore, there was a significant deterioration in the range of motion and an increased flexion contracture in the active mobilization group compared with 1 year after surgery. Grip strength deteriorated significantly in both groups from the 1-year to the 5-year minimum follow-up, but key pinch did not change. In both groups, DASH and ABILHAND scores improved from the 1-year to the 5-year minimum follow-up. Passive mobilization with place-and-hold following flexor tendon repair results in superior long-term outcomes compared with active mobilization. Therapeutic I.

Establishing a rabbit model with massive supraspinatus tendon defect for investigating scaffold-assisted tendon repair

BackgroundShoulder pain and disability from rotator cuff tears remain challenging clinical problem despite advancements in surgical techniques and materials. To advance our understanding of injury progression and develop effective therapeutics using tissue engineering and regenerative medicine approaches, it is crucial to develop and utilize animal models that closely resemble the anatomy and display the pathophysiology of the human rotator cuff. Among various animal models, the rabbit shoulder defect model is particularly favored due to its similarity to human rotator cuff pathology. However, a standardized protocol for creating a massive rotator cuff defect in the rabbits is not well defined. Therefore, the objective of our study was to establish a robust and reproducible model of a rotator cuff defect to evaluate the regenerative efficacy of scaffolds.ResultsIn our study, we successfully developed a rabbit model with a massive supraspinatus tendon defect that closely resembles the common rotator cuff injuries observed in humans. This defect involved a complete transection of the tendon, spanning 10 mm in length and encompassing its full thickness and width. To ensure stable scaffolding, we employed an innovative bridging suture technique that utilized a modified Mason-Allen suture as a structural support. Moreover, to assess the therapeutic effectiveness of the model, we utilized different scaffolds, including a bovine tendon extracellular matrix (ECM) scaffold and a commercial acellular dermal matrix (ADM) scaffold. Throughout the observation period, no scaffold damage was observed. Notably, comprehensive histological analysis demonstrated that the regenerative tissue in the tendon ECM scaffold group exhibited an organized and aligned fiber structure, indicating tendon-like tissue regeneration while the tissue in the ADM group showed comparatively less organization.ConclusionsThis study presents a comprehensive description of the implemented procedures for the development of a highly reproducible animal model that induces massive segmental defects in rotator cuff tendons. This protocol can be universally implemented with alternative scaffolds to investigate extensive tendon defects and evaluate the efficacy of regenerative treatments. The application of our animal model offers a standardized and reproducible platform, enabling researchers to systematically evaluate, compare, and optimize scaffold designs. This approach holds significant importance in advancing the development of tissue engineering strategies for effectively repairing extensive tendon defects.

Suramin enhances proliferation, migration, and tendon gene expression of human supraspinatus tenocytes.

Rotator cuff tendinopathy is a common musculoskeletal disorder with limited pharmacological treatment strategies. This study aimed to investigate tenocytes' functional in vitro response from a ruptured supraspinatus tendon to suramin administration and to elucidate whether suramin can enhance tendon repair and modulate the inflammatory response to injury. Tenocytes were obtained from human supraspinatus tendons (n = 6). We investigated the effect of suramin on LPS-induced inflammatory responses and the underlying molecular mechanisms in THP-1 macrophages. Suramin enhanced the proliferation, cell viability, and migration of tenocytes. It also increased the protein expression of PCNA and Ki-67. Suramin-treated tenocytes exhibited increased expression of COL1A1, COL3A1, TNC, SCX, and VEGF. Suramin significantly reduced LPS-induced iNOS, COX2 synthesis, inflammatory cytokine TNF-α production, and inflammatory signaling by influencing the NF-κB pathways in THP-1 cells. Our results suggest that suramin holds great promise as a therapeutic option for treating rotator cuff tendinopathy.

Surgical Treatment of Insertional Achilles Tendinopathy Augmented With Human Acellular Dermal Matrix: A Retrospective Case Series

Background: Insertional Achilles tendinopathy (IAT) is often surgically treated with Achilles tendon partial or total detachment, debridement and repair of the Achilles tendon, excision of retrocalcaneal exostosis, and suture anchor reattachment. To date, there is no report that examines the use of acellular dermal matrix (ADM) augmentation in this procedure without the use of suture anchor reattachment. Methods: Thirty-two female and 10 male patients (mean age 52 years) with IAT underwent surgical treatment including partial detachment of the Achilles tendon, excision of the retrocalcaneal exostosis, debridement and repair of the Achilles tendon, and augmentation with human acellular dermal matrix allograft. Outcomes measured were the visual analog scale (VAS) score, time to weightbearing, major and minor complications. Results: Forty-two patients were followed for a mean of 20.8 months. The VAS score improved from a mean of 5.1 to 1.9 at final follow-up. The mean time to weightbearing was 4.4 weeks. Eleven patients (26.2%) experienced complications. One patient (2.4%) suffered a rupture of the Achilles in the early postoperative period. Three patients (7.1%) had delayed wound healing, with 1 (2.4%) requiring surgical debridement. Two (4.8%) experienced continued pain requiring further surgical treatment. Conclusion: This protocol for surgical treatment of IAT with the use of human ADM allograft augmentation resulted in improved VAS scores and was associated with a low risk of postoperative infection without a prolonged nonweightbearing period. Level of Evidence: Level IV, retrospective case series.

Simultaneous targeting of TGF-β1/PD-L1 via a hydrogel-nanoparticle system to remodel the ECM and immune microenvironment for limiting adhesion formation.

Adhesion seriously affects the recovery of tendon gliding function. Our group previously found that inhibition of TGF-β1, which is closely related to adhesion formation, effectively attenuated adhesions but did not eliminate them, suggesting that there may be other mechanisms involved in adhesion formation. In this study, we considered that uncontrolled and excessively proliferating fibroblasts undergo immune escape, which aggravates the deposition of extracellular matrix during the adhesion formation. We found that the expression of the immune checkpoint PD-L1 was significantly elevated after injury and may be involved in adhesion formation. Therefore, we intended to silence both TGF-β1 and PD-L1 to improve the immune advantage in the microenvironment after flexor tendon injury to further reduce adhesion. We constructed the nanoparticle/TGF-β1 or/and PD-L1 siRNA complexes and verified their high biocompatibility and high transfection efficiency. We found that CD8+ T cells had a greater killing effect on the excessively proliferating cells that were transfected with nanoparticle/TGF-β1 or/and PD-L1 siRNAs. The hydrogel-nanoparticle/TGF-β1 or/and PD-L1 siRNA system could effectively improve the gliding function of the tendons without weakening the mechanical properties in injured rat FDL tendon and chicken FDP tendon models. In addition, the potential of CD8+ T cells to encircle the adhesion cells on the tendon surface was observed, which resulted in increased levels of cell apoptosis. Thus, our study confirmed that combined knockdown of TGF-β1 and PD-L1 could activate immunodominance after flexor tendon repair and provided a potential treatment to limit adhesion formation and improve gliding function. STATEMENT OF SIGNIFICANCE: Adhesion seriously affects the recovery of tendon gliding function. TGF-β1 is related to adhesion formation as it regulates the production of extracellular matrix. We found that excessively proliferated fibroblasts might undergo immune escape, which aggravated the deposition of extracellular matrix. Therefore, we constructed a hydrogel-nanoparticle/TGF-β1 and PD-L1 siRNAs system for silencing TGF-β1 and PD-L1 to improve the immune advantage in the microenvironment after tendon injury. This system could improve the gliding function of tendons without weakening the mechanical property and increase the killing effect of CD8+ T cells. Combined knockdown of TGF-β1 and PD-L1 could activate immunodominance after tendon repair and provide a potential treatment to limit adhesion formation.

Distal biceps tendon repair: outcome and complications with single incision anchor fixation.

The purpose of this study is to evaluate the functional outcome and quality of life in distal biceps tendon repair with single incision technique and anchor fixation method. A retrospective cohort study was made of patients with complete distal biceps tendon rupture. The chosen repair method was single incision technique with anchor fixation. The outcome was assessed with functional testing of the elbow with strength and ROM. Additionally Mayo elbow performance index, Oxford elbow score, Disability arm hand shoulder questionnaire and patient rated elbow evaluation scores were used to evaluate quality of life. Of the 28 patients, the average strength in flexion and supination was decreased with 91% and 89% of the strength compared to the non-injured arm. ROM was preserved in flexion, extension, supination and pronation. The mean scores for quality of life evaluation were MEPS = 96 ± 7.8, OES = 46.8 ± 1.9, DASH = 1.0 ± 1.9 and PREE = 2.0 ± 3.6. LABCN injury was the most common temporary complication with 30% followed by pain with 23%. Two patients were identified with HO and 1 patient was identified with median nerve injury. There were no cases of radioulnar synostosis and PIN injury. Overall strength in flexion and supination were slightly decreased with preserved ROM. Patients reported nearly perfect quality of life as demonstrated with the scores. The complications rate was high with mainly minor complications. Distal biceps tendon repair with single incision technique and anchor fixation overall leads to a very satisfying outcome.