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Background Given rising youth sport participation, 8 to 10-year-olds increasingly display comparable lower-extremity injury incidence to 11 to 17-year-olds and require effective return to sport criteria. One such criterion which quantifies dynamic stability is the Y-Balance Test (YBT), though it has not been validated in children under age 11. Hypothesis/Purpose The purpose of this study was to examine the performance of 8 to 10-year-old patients on the YBT after lower-extremity injury and determine how these results compare to larger samples of age-grouped athletes within the validated 11 to 17-year-old range. It was hypothesized that 8 to 10-year-olds would display different normalized YBT distances compared to 11 to 17-year-olds. Study Design Cross-sectional Study. Methods Patients (N=1093) aged 8 to 17 who presented to a pediatric sports medicine practice with a lower-extremity injury and completed the YBT between December 2015-May 2021 were included. Anterior, posteromedial, and posterolateral YBT scores were collected at return-to-sport for affected and unaffected limbs. Scores were normalized to limb length, and composite scores were created. Between-limb differences were calculated in groups of ages 8-10, 11-12, 13-14, and 15-17. Groups were also evaluated for differences by sex. Results A rise in performance was observed in unaffected limb anterior reach from ages 8 to 10 years to 11 to 12 years followed by a subsequent significant decrease at older ages (p<0.001). Affected limb anterior reach differed between the youngest group and two oldest groups (p=0.004). Anterior and composite difference were significantly different between the oldest three groups (p=0.014 anterior; p=0.024 composite). No differences were observed between sexes in 8 to 10-year-olds, though 11 to 12-year-old females reached further during all eight distances. In the older three groups, males generally displayed greater between-limb differences. Conclusion YBT scores, specifically anterior reach, demonstrated inconsistency by age and sex across a large adolescent cohort. Existing return-to-sport standards should not be used with younger athletes, and individual validation is required. Level of Evidence Level III [ABSTRACT FROM AUTHOR]

Background: Recent advancements in artificial intelligence have proven their effectiveness in orthopaedic settings, especially in tasks like medical image analysis. This study compares human musculoskeletal radiologists to artificial intelligence in a novel, detailed, short, and cost-effective examination of Achilles tendon magnetic resonance images to uncover potential disparities in their reasoning approaches. Aiming to identify relationships between the structured assessment of the Achilles tendon and its function that could support injury prevention. We examined 72 athletes to investigate the link between Achilles tendon structure, as visualised in magnetic resonance images using a precise T2*-weighted gradient echo sequence with very short echo times, and its functional attributes. The acquired data were analysed using advanced artificial intelligence techniques and reviewed by radiologists. Additionally, we conducted statistical assessments to explore relationships with functional studies in four meaningful groups: dynamic strength, range of motion, muscle torque and stabilography. Results: The results show notable linear or non-linear relationships between functional indicators and structural alterations (maximal obtained Spearman correlation coefficients ranged from 0.3 to 0.36 for radiological assessment and from 0.33 to 0.49 for artificial intelligence assessment, while maximal normalised mutual information ranged from 0.52 to 0.57 for radiological assessment and from 0.42 to 0.6 for artificial intelligence assessment). Moreover, when artificial intelligence-based magnetic resonance assessment was utilised as an input, the associations consistently proved more robust, or the count of significant relationships surpassed that derived from radiological assessment. Ultimately, utilising only structural parameters as inputs enabled us to explain up to 59% of the variance within specific functional groups. Conclusions: This analysis revealed that structural parameters influence four key functional aspects related to the Achilles tendon. Furthermore, we found that relying solely on subjective radiologist opinions limited our ability to reason effectively, in contrast to the structured artificial intelligence assessment. Study Design: Cross-sectional studies. Key Points: •Establishment of a relationship between magnetic resonance imaging-based structural features and functional characteristics of the Achilles tendon, emphasising non-linear connections. •Introduction of a fast and efficient magnetic resonance imaging protocol for concurrent evaluation of structural and functional aspects, alongside a comparative analysis of artificial intelligence and radiologist reasoning capabilities. •Highlighting the advantages of artificial intelligence-driven reasoning in identifying structural biomarkers, offering potential enhancements for injury prevention strategies and personalised treatment approaches. [ABSTRACT FROM AUTHOR]

Scaffolds play a crucial role in tendon healing by providing structural support, promoting cell infiltration, and guiding tissue regeneration. Polycaprolactone (PCL) has been used as a polymer in biological scaffolds for several tissue engineering studies. This study aimed to investigate the effects of curcumin-loaded PCL scaffold on Achilles tendon using a tenotomy model in rats. Twenty adult male Wistar rats were randomized into two groups. In control group, tenotomy and suture placement were performed. The identical intervention followed by the implantation of curcumin-loaded PCL scaffold around the tendon stumps was performed in the treatment group. The nanofibrous PCL scaffold containing 5.00% curcumin was fabricated by electrospinning. Walking track analysis was performed weekly. Then, after 6 weeks, histopathological examination and tendon mechanical tests were performed. The weekly walking track analysis revealed a significant improvement in Achilles functional index in scaffold-treated rats from week three to six. The rate of functional improvement was remarkably slower in the control group. Histopathological examination revealed aseptic inflammation and enhanced neovascularization in the treatment group. Also, collagen arrangement and density were significantly improved in this group compared to the control samples including less regular orientation and loose organization of collagen fibers. Significant increase in mechanical properties, except for strain, was observed in the treatment group. The present study demonstrated that implantation of curcumin-loaded PCL scaffold resulted in increased fibrillar architecture, as well as improved mechanical properties and Achilles functional index in rats. To reduce the biodegradation-induced inflammation, an antiinflammatory treatment is recommended. [ABSTRACT FROM AUTHOR]

Tendons play fundamental roles in the execution of human movement and therefore understanding tendon function, health and disease is important for everyday living and sports performance. The acute mechanical behavioural and physiological responses to short-term loading of tendons, as well as more chronic morphological and mechanical adaptations to longer term loading, differ between sexes. This has led some researchers to speculate that there may be a sex-specific injury risk in tendons. However, the link between anatomical, physiological and biomechanical sex-specific differences in tendons and their contributory role in the development of tendon disease injuries has not been critically evaluated. This review outlines the evidence surrounding the sex-specific physiological and biomechanical responses and adaptations to loading and discusses how this evidence compares to clinical evidence on tendon injuries and rehabilitation in the Achilles and patellar tendons in humans. Using the evidence available in both sports science and medicine, this may provide a more holistic understanding to improve our ability to enhance human tendon health and performance in both sexes. [ABSTRACT FROM AUTHOR]

Background: Surgery is widely recognized as an effective treatment for Achilles tendon rupture; however, there remains debate regarding the optimal surgical approach. Purpose: To compare the biomechanical properties of 2 techniques, the H-loop knotless double-row (HLDR) suture repair and the Krackow suture repair, for Achilles tendon rupture in a cadaveric model. Study Design: Controlled laboratory study. Methods: Ten matched Achilles tendon specimens from 5 male and 5 female donors were obtained. Each specimen from a matched pair was randomly distributed to 1 of 2 repair groups, the HLDR group or the Krackow group. Tendon elongation was recorded after exposure to 10, 100, 200, 400, 600, 800, and 1000 load cycles. The gap distance after application of a 100-N force, the force needed to produce a 2-mm gap, and the load to failure were measured. All biomechanical properties were compared between the HLDR and Krackow groups using the paired t test. Results: The HLDR group consistently exhibited significantly less elongation than the Krackow group after exposure to the 7 load cycles (P <.01 for all). In addition, the HLDR group exhibited a significantly smaller gap distance after applying a 100-N force (0.30 ± 0.02 vs 8.10 ± 0.46 mm for Krackow group), required significantly more force to generate a 2-mm gap (419.68 ± 39.48 vs 22.29 ± 3.40 N for the Krackow group), and had a significantly higher ultimate failure load (519.91 ± 57.29 vs 220.30 ± 19.27 N for the Krackow group) (P <.01 for all). Conclusion: The study findings demonstrated that the HLDR technique had more advantages compared with the Krackow technique with regard to elongation after different cyclic loadings, gap distance after a 100-N load, force needed to produce a 2-mm gap, and load to failure in a cadaveric model. Clinical Relevance: The HLDR technique could be a viable option for Achilles tendon rupture repair. [ABSTRACT FROM AUTHOR]

To examine the relationship between Achilles-tendon (AT) and patellar-tendon (PT) structure, clinical-examination and tendon pain in young gymnasts; and, to explore the associations between these factors and age, maturation, and training-load. Two hundred and seventy-four female gymnasts (aged 12.1±1.9 yrs) were assessed for anthropometric measures, pubertal-stage, and training-load. They had clinical-tests (pain-on-palpation for AT and pain-on-palpation and Royal-London Hospital-Test for PT), were asked about tendon-pain during-loading and were assessed for tendon-structure. Gymnasts with positive clinical-tests (with and without pain during-loading) presented a significantly higher prevalence of disorganized AT and PT compared to gymnasts with negative clinical-tests (with and without pain during-loading) (p<0.05). A significant pubertyXpositive clinical-test interaction was found for disorganized PT structure, whereby a disorganized structure was more prevalent among post-pubertal gymnasts with positive clinical-tests compared to pre-pubertal participants with negative clinical-tests (F(1, 263)=9.436, p=0.002). In gymnasts with positive clinical-tests, significant correlations were found between disorganized AT and PT structures and age, and training-load (p<0.05). An increased prevalence of disorganized tendon structure (regardless of pain during-loading) was seen in participants with positive clinical-tests. This disorganized tendon-structure was found to be significantly related to increased age, post-pubertal stage, and higher training hours in gymnasts with positive clinical-tests. [ABSTRACT FROM AUTHOR]

There are relatively few running studies that have attempted to prospectively identify biomechanical risk factors associated with Achilles tendon (AT) injuries. Therefore, the aim was to prospectively determine potential running biomechanical risk factors associated with the development of AT injuries in recreational, healthy runners. At study entry, 108 participants completed a set of questionnaires. They underwent an analysis of their running biomechanics at self-selected running speed. The incidence of AT running-related injuries (RRI) was assessed after 1-year using a weekly questionnaire standardized for RRI. Potential biomechanical risk factors for the development of AT RRI injury were identified using multivariable logistic regression. Of the 103 participants, 25% of the sample (15 males and 11 females) reported an AT RRI on the right lower limb during the 1-year evaluation period. A more flexed knee at initial contact (odds ratio = 1.146, P =.034) and at the midstance phase (odds ratio = 1.143, P =.037) were significant predictors for developing AT RRI. The results suggested that a 1-degree increase in knee flexion at initial contact and midstance was associated with a 15% increase in the risk of an AT RRI, thus causing a limitation of training or a stoppage of running in runners. [ABSTRACT FROM AUTHOR]

Background: There are many adhesion barrier materials, cross-linked or non-cross-linked hyaluronic acid (HA), used during surgeries. Purpose: This study investigates the efficacy of cross-linked and non-cross-linked HA in preventing Achilles tendon adhesions. We hypothesized that non-cross-linked HA may be more effective than cross-linked HA in preventing Achilles tendon adhesions following injury and repair. Methods: Twenty male Sprague Dawley rats, totaling 40 legs, underwent Achilles tendon transection and repair. Following the surgery, they were treated simultaneously with cross-linked and non-cross-linked HA formulations. The rats were divided into four groups: a positive control group, a group treated with BMC non-cross-linked HA gel, a group treated with DEFEHERE cross-linked HA gel, and a group treated with ANIKA cross-linked HA gel. Four weeks after surgery, macroscopic evaluation of peritendinous adhesion and histological analysis were conducted to assess the effectiveness of the treatments. Results: Non-cross-linked BMC HA demonstrated superior efficacy in preventing tendon adhesions compared to cross-linked HA and control groups. Histological analysis confirmed reduced adhesion severity in the non-cross-linked HA group (P < 0.05). The findings support the potential of non-cross-linked HA as a treatment to inhibit tendon adhesions. Further research, including clinical trials, is warranted to validate these results in human subjects. Conclusions: Non-cross-linked BMC HA had significantly lower tendon adhesions parameters and better healing scores in histological analysis than cross-linked HA and control group did. Non-cross-linked HA holds promise as a potential treatment to inhibit the formation of such adhesions. [ABSTRACT FROM AUTHOR]

Background: Achilles tendon is vital in maintaining the stability and function of ankle joint. It is quite difficult to achieve the structural and functional repair of Achilles tendon in tissue engineering. Methods: A tissue-engineered tendon micro-tissue was prepared using rat tail tendon extracellular matrix (TECM) combined with rat adipose stem cells (ADSCs) to repair Achilles tendon injuries. The TECM was prepared by repeated freezing and thawing. The in vitro characteristics of TECM and its effect on ADSCs proliferation were detected. This tissue-engineered tendon micro-tissue for Achilles tendon repair in vivo was evaluated based on general characteristics, gait analysis, ultrasound findings, histological analysis, and biomechanical testing. Results: The results showed that the TECM scaffold had good biocompatibility for ADSCs. At 2 weeks post-surgery, collagen types I and III and tenomodulin expression were higher, and vascular endothelial growth factor expression was lower in the micro-tissue group than other groups. At 4 and 8 weeks post-surgery, the results of histological analysis and ultrasound findings showed that the repaired tendon tissue was smooth and lustrous, and was arranged regularly and evenly in the micro-tissue group. Gait analysis confirmed that better motor function recovery was noted in micro-tissue group than other groups. In addition, the mechanical properties of the repaired tendon tissue in micro-tissue group were better than other groups. Conclusion: Tissue-engineered tendon micro-tissue fabricated by TECM and ADSCs has good biocompatibility and can promote structural and functional repair of tendon in vivo. This composite biomaterial has broad application prospects in tissue engineering. [ABSTRACT FROM AUTHOR]

Objectives: Acute rupture of achilles tendon is a commonly occurring injury affecting mostly the young individuals involved in sports activities. Operative management is most often employed to treat such injuries. This study was aimed to evaluate the functional outcome in patients with acute tendo achilles tear managed by open repair using a suture anchor. Methods: This was a prospective study conducted between September 2018 to August 2020 on patients who underwent suture anchor repair for acute tendo achilles tear. All patients were followed up for at least 9 months. The patients were clinically evaluated and AOFAS score was used to assess their functional outcome. Results: In a total of 38 patients, 28 (73.7%) patients showed Excellent and 7 (18.4%) patients had Good results whereas 1 (2.6%) had Fair and 2 (5.3%) patients demonstrated Poor surgical result at the final follow-up. 89.5% patients did not have any complication. The average AOFAS score was 90.97 ± 10.24. Conclusion: Operative treatment with suture anchor in acute tendo achilles tear has a high success rate, quick recovery after surgery, lower rate of complications, faster return to daily activities, excellent aesthetic and comparable functional results and is also a safe, simple and accepted surgical technique. [ABSTRACT FROM AUTHOR]

Tendons are connective tissues with limited healing potential which results in permanently impaired function. Although direct mechanical testing of tendon remains the gold standard for functional analyses, this assay is terminal and tracking healing over time requires the use of many animals. An alternative method for quantifying tendon function is gait analysis, which is non-terminal and enables longitudinal tracking of the same animal. To date, commercial systems used to analyze gait are mostly applied to study neurobehavior, and applications for tendon research has been limited. Since these systems typically output many parameters, it is challenging to know which parameter is most relevant for a specific injury model. To address this challenge, we used a well-established rodent locomotion system (CatWalk XT) to measure longitudinal gait parameters in sham and Achilles tendon-injured mice (from PREOP to 56 days post-injury) and identified relevant and reproducible parameters specifically associated with Achilles tendon injury and healing. Micro computed tomography (micro- CT) and mechanical testing also confirmed persistent tendon impairment in the same animals at the terminal timepoint. Collectively, our results provide a useful reference and recommendation of CatWalk gait parameters and the control comparisons that both conserve the use of animals while maintaining high reproducibility standards for Achilles tendon injury studies. [ABSTRACT FROM AUTHOR]

• The incidence of Achilles tendinopathy was 4.2% during 20 weeks of follow-up among recreational runners. About two-thirds of the onsets were categorized as insertional Achilles tendinopathy, and about one-third were midportion subtype. • No significant association between training load and onset of Achilles tendinopathy was found so far. Future studies should apply more advanced serial measures of training load to identify whether overuse is a risk factor for Achilles tendinopathy. • The observed different risk factors between midportion and insertional Achilles tendinopathy were limited. It is questionable whether there is solid ground to regard them as subcategories from a clinical perspective. Achilles tendinopathy (AT) is a common problem among runners. There is only limited evidence for risk factors for AT, and most studies have not defined the AT subcategories. No study has compared the incidence and risk factors between insertional AT and midportion AT, though they are considered distinct. This study aimed to assess incidence and risk factors of AT based on data from a large prospective cohort. The secondary aim was to explore differences in risk factors between insertional and midportion AT. Participants were recruited from among registered runners at registration for running events. Questionnaires were completed at baseline, 1 month before the event, 1 week before the event, and 1 month after the event. Information concerning demographics, training load, registered events, and running-related injuries were collected at baseline. The follow-up questionnaires collected information about new injuries. A pain map was used to diagnose midportion and insertional AT. The primary outcome was the incidence of AT. Multivariable logistic regression analysis was applied to identify risk factors for the onset. We included 3379 participants with a mean follow-up of 20.4 weeks. The incidence of AT was 4.2%. The proportion of insertional AT was 27.7% and of midportion AT was 63.8%; the remaining proportion was a combined type of insertional and midportion AT. Men had a significantly higher incidence (5%, 95% confidence interval (95%CI): 4.1%–6.0%) than women (2.8%, 95%CI: 2.0%–3.8%). AT in the past 12 months was the most predominant risk factor for new-onset AT (odds ratio (OR) = 6.47, 95%CI: 4.27 –9.81). This was similar for both subcategories of AT (insertional: OR = 5.45, 95%CI: 2.51–11.81; midportion: OR = 6.96, 95%CI: 4.24–11.40). Participants registering for an event with a distance of 10/10.55 km were less likely to develop a new-onset AT (OR = 0.59, 95%CI: 0.36–0.97) or midportion AT (OR = 0.47, 95%CI: 0.23 –0.93). Higher age had a significant negative association with insertional AT (OR = 0.97, 95%CI: 0.94–1.00). The incidence of new-onset AT among recreational runners was 4.2%. The proportion of insertional and midportion AT was 27.7% and 63.8%, respectively. AT in the past 12 months was the predominant risk factor for the onset of AT. Risk factors varied between insertional and midportion AT, but we could not identify clinically relevant differences between the 2 subtypes. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Achilles tendon injuries often generate substantial discussion in the mainstream media. The Altmetric Attention Score (AAS) measures the online dialogue pertaining to Achilles tendon research that occurs outside scientific journals, which traditional citation-based metrics fail to capture. Purpose: To characterize the top 100 most-cited Achilles tendon articles and compare them with the 100 Achilles tendon articles with the highest AAS. A secondary goal was to gain an improved understanding of the online dissemination and interpretation of Achilles tendon research through this comparison. Study Design: Cross-sectional study. Methods: The Web of Science Clarivate database was queried to isolate the 100 most-cited Achilles tendon articles, and the Altmetric database was queried to identify the Achilles tendon articles with the top 100 AAS values. Data elements were extracted for each article including study type, study topic, and geographic origin. Results: The Web of Science Clarivate database search yielded 10,890 articles published between 1970 and 2021. The 100 most-cited articles were published in 35 journals, with the American Journal of Sports Medicine being the most prevalent. The mean (±SD) number of citations was 214.5 ± 86.47. The most prevalent study type was laboratory (28.0%). The most prevalent study topic was treatment (41.0%). Of these articles, 72.0% were European. The Altmetric database search yielded 3810 articles published between 1957 and 2021. The AAS of the top 100 articles ranged from 37 to 476 with a mean of 98.17 ± 85.53. The selected articles were published in 39 journals, with the British Journal of Sports Medicine being the most prevalent. The most prevalent study type was randomized controlled trial (25.0%). The most common study topic was treatment (40.0%). Of these articles, 46.0% were European. Conclusion: Our findings suggest that, although the scientific community remains committed to high-impact journals with articles backed by high citation numbers, there is an increasing opportunity to consume Achilles tendon literature through social media. [ABSTRACT FROM AUTHOR]

Background. Despite the many accesses described in the literature for open Achilles tendon repair, there is no evidence of the benefits of this or that access confirmed by clinical observations.The aim is to determine and justify optimal access during open Achilles tendon repair.Material and methods. The article shows the result of the analysis of data from a literary search, experimental work on 12 lower limbs of 6 cadavers, a clinical study based on a retro-prospective analysis of the treatment of 128 people in the Department of Emergency Traumatology N.V. Sklifosovsky Research Institute from 2014 to 2022. The comparison group retrospectively included 47 patients (36.7%) with Achilles tendon injury, who underwent suture of the Achilles tendon from S and Z–shaped accesses from 2014 to 2017. The main group prospectively included 81 patients (63.3%) for 2018-2022, who underwent paramedial tendon access.Results. The analysis of a retrospective study showed that 3 patients from the comparison group with Achilles tendon injury in the postoperative period had ischemia of the wound edges with subsequent formation of necrosis and skin defect; 1 patient had a hypertrophic painful scar, which ulcerated from the constant traumatization of his shoe back (the total number of complications was 8.5%). In the patients of the main group, there were no complications in the postoperative period in any case. Conclusion. In our opinion, the paramedial tendon access is optimal, because there are no complications from the skin and leads to improved functional results.

Objectives: Commercial compression sleeves have been promoted to ameliorate pain secondary to arthritis and tendinopathy. The fabric of one particular sleeve is embedded with nano-semiconductor fibers that reflect thermal energy produced by the body at a photonic wavelength mimicking low-level laser therapy. The device is theorized to accelerate the inflammatory stage of tissue healing to reach the proliferation and remodeling stages at faster rates. Previous clinical studies have shown a significant improvement in patient-reported outcomes between patients who did and did not use this sleeve to treat osteoarthritis. The objective of this investigation was to determine if compression sleeves embedded with nano-semiconductor fibers can accelerate Achilles tendon healing in a rabbit model. Methods: Twelve New Zealand White rabbits—under IACUC approval—were administered intratendinous injections of 0.2% collagenase into the right Achilles tendon to simulate an acute tendon injury. Rabbits were divided into three groups: group I received the commercial compression sleeve without nano-semiconductors (n = 4), group II received the sleeve with nano-semiconductors (n = 4), and group III received an alternate sleeve design also with nano-semiconductors (n = 4). Calf circumference measurements and thermal radiation imaging of the right lower leg of each rabbit were collected days 7, 14, 21, and 28 post-injection. Two rabbits from each group were sacrificed at the 14-day and 28-day marks and the right Achilles tendons were harvested. Histological analysis using picrosirius red staining was performed to evaluate tissue organization. A custom MATLAB program (MathWorks, Natick, MA) was used to quantify the collagen fiber dispersion within the Achilles tendon samples. Results: A statistically significant difference in calf circumference was found at the 28-day mark between group I versus groups II and III: group I had an average calf circumference of 5.2 cm while groups II and III had an average calf circumference of 4.85 cm (p = 0.036) and 4.60 cm (p = 0.021) respectively. Additionally, after 28 days, group I demonstrated an average pixel density intensity on thermal radiation imaging of 1,531,192 while groups II and III yielded average pixel density intensities of 1,363,515 (p = 0.008) and 1,335,456 (p = 0.003) respectively. Histological staining showed observable alterations in collagen architecture, with group I displaying widespread disorganization and degradation of type I and type III collagen fibers near the injection site. Groups II and III displayed greater organization at the 28-day mark in comparison to group I, with signs of tissue proliferation and remodeling evident. No statistically significant differences were found between group I versus groups II and III regarding collagen fiber dispersion at both the 2-week mark (p = 0.145, p = 0.236) and the 4-week mark (p = 0.113, p = 0.268), respectively. Conclusions: The nano-semiconductor fibers embedded within a commercial sleeve significantly decreased swelling and temperature of the lower leg 28 days following acute Achilles tendon injury in a rabbit model. Furthermore, histologic analysis demonstrated greater collagen fiber and extracellular matrix organization as well as greater proliferation of type III collagen suggesting a faster transition to the proliferation stage of tissue healing. [ABSTRACT FROM AUTHOR]

Background. Tendon injuries are responsible for a crescent number of people retirement around the world. Recently, cell-based therapies has been shown to be effective for the treatment of tendon injures. Objective. We aimed to evaluate the effect of local treatment with conditioned medium produced by tenocytes cell cultures on the histological and functional recovery in tenotomized mice. Methods. The tendon cells were cultured for conditioning culture medium that will be used as treatment. The animals were subjected to right Aquilles tenotomy and treated with saline solution (SAL), DMEM (DMEM) and DMEM conditioned in tenocytes cultures (CM) and compared to the control group (CTRL). For histological analysis, tissues were stained with HE. Tendon functionality was measured using the Achilles Functional Index (AFI) and mechanical sensitivity through the paw withdrawal threshold (PWT) using the Von Frey test. Analyzes were performed at 7-, 14- and 21-days post-injury (dpi). Statistics were performed by ANOVA-2 followed by Tukey's post-test, p < 0.01. Results. In the histological analysis, the CM group showed better tissue organization when compared to SAL and DMEM groups. The CM group showed improvement in the PWT at 7° and 14° dpi (2.24 ± 1.15; 2.66 ± 1.06) compared to the DMEM (0.15 ± 0.07; 0 .45 ± 0.76 p < 0.01) and SAL (0.13 ± 1.15; 0.77 ± 0.95 p < 0.01). The CM group showed functional improvement at 7° and 14° dpi (-40.4 ± 12.6; -36.6 ± 10.4) compared to the DMEM (-76.5 ± 11.7; -71, 6 ± 7.9, p < 0.01) and SAL (-88.8 ± 15; -71.4 ± 12.6 p < 0.01). Conclusions. We conclude that treatment with tenocytes conditioned medium accelerates tendon recovery, promoting improvement in mechanical sensitivity, functionality and tissue organization in the proposed injury model. [ABSTRACT FROM AUTHOR]

The therapeutic role of tendon stem cells (TSCs) in tendon-related injuries has been well documented. Small extracellular vesicles (sEVs) are being increasingly used as new biotherapeutic agents for various diseases. Therefore, the potential function of TSC-sEVs in tendon injury repair warrants further investigation. In this study, we explored the effects of TSC-sEVs on TSC proliferation, migration, and differentiation in vitro in an autocrine manner. We further used a novel exosomal topical treatment with TSC-sEVs loaded with gelatin methacryloyl (GelMA) hydrogel in vivo ; we mixed sufficient amounts of TSC-sEVs with GelMA hydrogel to cover the damaged molded Achilles tendon tissue and then exposed them to UV irradiation for coagulation. GelMA loading ensured that TSC-sEVs were slowly released at the injury site over a long period, thereby achieving their full local therapeutic effects. Treatment with TSC-sEVs loaded with GelMA significantly improved the histological score of the regenerated tendon by increasing the tendon expression while inhibiting the formation of excessive ossification and improving the mechanical properties of the tissue. Moreover, miRNA sequencing in TSC-sEVs, TSCs, and TSCs receiving sEVs revealed that TSC-sEVs altered the miRNA expression profile of TSCs, with increased expression of miR-145-3p. In conclusion, our study demonstrates that TSC-sEVs can play a key role in treating tendon injuries and that loading them with GelMA can enhance their effect in vivo. Moreover, miR-145-3p has a major functional role in the effect of TSC-sEVs. This study offers new therapeutic ideas for the local treatment of Achilles tendon injuries using sEVs. In this study, we demonstrated that TSC-sEVs play a key role in treating tendon injuries and that loading them with GelMA hydrogel can act as a fixation and slow release in vivo. Moreover, it identifies the major functional role of miR-145-3p in the effect of TSCs that were identified and validated by miRNA sequencing. Our study provides a basis for further research on GelMA slow-release assays that have potential clinical applications. It offers new therapeutic ideas for the local treatment of Achilles tendon injuries using TSC-sEVs. [Display omitted] [ABSTRACT FROM AUTHOR]

The plantar muscle is fusiform, attaching to the calcaneus, starting behind the knee. Plantaris muscle formation has been reported in humans at a rate approaching 90%. It is frequently preferred for tendon grafting and tendon transfer in hand surgery and Achilles tendon injuries. In this study, our goal is to investigate the frequency of the presence of the plantar muscle in the Somali population. We retrospectively analyzed 607 knee MRI scans performed at Recep Tayyip Erdoğan Training and Research Hospital in Mogadishu between January 2019 and March 2022. The clinical and demographic characteristics of the patients were recorded. Patients with muscle trauma and previous surgery involving muscles, proximal tibia fracture surgery, and soft tissue tumors were dropped out of the study. 469 (77.3%) of these patients were male and 138 (22.7%) were female.182 (72%) of the male patients with right MRI saw plantaris while 68 (28%) did not. While plantaris was seen in 183 (83.5%) of the male patients who underwent left-sided MRI, plantaris was not seen in 30 (16.5%). Plantaris was seen in 62 (79.5%) of the female patients who had right-sided MRI, while plantaris was not seen in 16 (20.5%). Left plantar was present in 55 (91.7%) and absent in 5 (8.3%) female patients who underwent left-sided MRI. Since the plantaris muscle is used as a tendon graft, pre-op evaluation of its presence is important in terms of surgery and can change the surgical procedure. The presence of the plantar tendon can be revealed by using knee MRI in the Somali population living in the African continent. [ABSTRACT FROM AUTHOR]

Background. L-carnitine (LC), which has anti-inflammatory and antioxidant effect, is especially consumed by sportmans to increase muscle mass recently. Therefore, the functional, histopathological effects of LC on experimental Achilles tendon injury were investigated in this study. Methods. Forty male Wistar Albino rats were randomly divided into four groups (n = 10). A tendon injury model was created by clamping the left Achilles tendon of all rats except the control group. Tendon Injury Group (TIG) and the Control group did not receive LC treatment. LC (100 mg/kg/day, intraperitoneally) was started to administer one week before the injury model in pre-LC group and the same day of injury in post-LC group following the establishment of model for four weeks. After the tendon injury and at the end of the experiment, rats in all groups were subjected to a Gait test (GT) twice. On the 30th day of injury, the rats were sacrificed, and left Achilles tendons were dissected for histopathological analysis. Results. Initial GT data were significantly different between the control and other groups (p < 0.001). The final GT data were significantly different only between the Control and TIG (p = 0.002). Histopathological examination revealed that neovascularization, fibroblastic activity, and collagen fibril sequencing parameters were found to be significantly different amongst the TIG and pre-LC group, and post-LC group (p < 0.05). Conclusions. LC contributes to the tendon healing by histopathologically and functionally. [ABSTRACT FROM AUTHOR]

Achilles' tendon (AT) injuries such as ruptures and tendinopathies have experienced a dramatic rise in the mid- to older-aged population. Given that the AT plays a key role at all stages of locomotion, unsuccessful rehabilitation after injury often leads to long-term, deleterious health consequences. Understanding healthy in vivo strains as well as the complex muscle–tendon unit interactions will improve access to the underlying aetiology of injuries and how their functionality can be effectively restored post-injury. The goals of this survey of the literature with a systematic search were to provide a benchmark of healthy AT strains measured in vivo during functional activities and identify the sources of variability observed in the results. Two databases were searched, and all articles that provided measured in vivo peak strains or the change in strain with respect to time were included. In total, 107 articles that reported subjects over the age of 18 years with no prior AT injury and measured while performing functional activities such as voluntary contractions, walking, running, jumping, or jump landing were included in this review. In general, unclear anatomical definitions of the sub-tendon and aponeurosis structures have led to considerable confusion in the literature. MRI, ultrasound, and motion capture were the predominant approaches, sometimes coupled with modelling. The measured peak strains increased from 4% to over 10% from contractions, to walking, running, and jumping, in that order. Importantly, measured AT strains were heavily dependent on measurement location, measurement method, measurement protocol, individual AT geometry, and mechanical properties, as well as instantaneous kinematics and kinetics of the studied activity. Through a comprehensive review of approaches and results, this survey of the literature therefore converges to a united terminology of the structures and their common underlying characteristics and presents the state-of-knowledge on their functional strain patterns. [ABSTRACT FROM AUTHOR]

Background: Rupture of the Achilles tendon is a considerable cause of morbidity with reduced function following injury. Randomized studies have so far failed to show a difference in outcome between operative and nonoperative management of Achilles tendon rupture, provided that no re-rupture occurs. Percutaneous Achilles repair has been suggested to result in superior patient satisfaction compared with open repair in patients with an acute Achilles tendon rupture. Aim and Objectives: To assess and evaluate the functional outcome after percutaneous repair in patients of the acute and closed Achilles tendon ruptures. Materials and Methods: It was a prospective study conducted on patients diagnosed as having rupture of the Achilles tendon. A total of 25 patients with mean age of 44.4 (range 19–65) years were taken, who underwent percutaneous Achilles tendon repair. Results: The number of patients who reported excellent or good scores (ATRS > 80) at 3, 6 and 12 months were 0%, 16% and 100%, respectively. The mean AOFAS hind foot score at 3-, 6- and 12-month follow-ups was 77.9 ± 4.3, 92.04 ± 2.4 and 96.16.32 ± 1.1, respectively. The number of patients who reported excellent or good scores (AOFAS > 74) at 3, 6 and 12 months were 76%, 100% and 100%, respectively. Most of the patients in our study showed no complications, and only 2 (8%) of patients had the features of sural nerve injury which was resolved in the subsequent follow-ups. Conclusion: Percutaneous repair of the Achilles tendon is an effective procedure which gives excellent functional outcome with very few complications. The percutaneous technique gives an additional advantage of less operative time, no wound complications, less damage to the soft tissues, and improved cosmesis as compared to the open repair. [ABSTRACT FROM AUTHOR]

The rate of lower extremity musculoskeletal injury (LE MSK) is elevated after concussion; however, the underlying mechanism has not been elucidated. Physical characteristics have been investigated despite poorer mental health being a common postconcussion complaint and linked to MSKs. To evaluate the role of mental health as a predictor of postconcussion LE MSK. Case-control study. Intercollegiate athletic training facility. A total of 67 National Collegiate Athletic Association Division I student-athletes (n = 39 females) who had been diagnosed with a sport-related concussion. The Brief Symptom Inventory-18, Hospital Anxiety and Depression Scale, and Satisfaction With Life Scale (SWLS) measures were completed at baseline (preseason) and on the day participants were cleared for unrestricted return to play (RTP) after a concussion. Two binary logistic regressions were used to predict postconcussion LE MSK within a year, one for the baseline time point and the second for the RTP time point. A 2 (group: LE MSK, no LE MSK)-by-2 (time: baseline, RTP) repeated-measures analysis of variance compared performance between baseline and RTP. Subsequent LE MSKs were sustained by 44 participants (65.7%). The only significant predictor of postconcussion LE MSK was the SWLS score at RTP, with Exp(B) = 0.64, indicating that an increased (improved) SWLS score was associated with a lower LE MSK rate. No significant interactions were present between mental health measures and subsequent MSK (P values =.105–.885). Limited associations were evident between postconcussion LE MSK and scores on commonly used measures of anxiety, depression, and satisfaction with life. Reported increased satisfaction with life was associated with a decreased injury risk, which warrants further attention. Our results suggest that these measures of anxiety, depression, and satisfaction with life have limited value in assisting sports medicine clinicians with determining which student-athletes are at elevated risk of postconcussion LE MSK. [ABSTRACT FROM AUTHOR]

Background: Achilles tendon injuries represent one of the most common reasons for referral to orthopaedic surgeons. Purpose: To outline the characteristics, examine trends in publication, and evaluate the correlation between citations and study quality of the 50 most cited articles on Achilles tendon injury. Study Design: Cross-sectional study. Methods: After searching the Web of Science for articles published in orthopaedic journals, we identified the 50 most cited articles on Achilles tendon injury and abstracted their characteristics. Risk of bias was assessed using the modified Coleman Methodology Score (mCMS). Multiple bivariate analyses (Pearson or Spearman correlation coefficient) were used to evaluate the association among number of citations, citation rate (citations/year), 2020 journal impact factor (JIF), year of publication, level of evidence (LoE), study type (tendon rupture or chronic tendinopathy), sample size, and mCMS. Results: The top 50 articles were cited 12,194 times. Each article had a mean ± SD 244 ± 88.8 citations (range, 157-657) and a citation rate of 12.6 ± 5.4 per year (range, 3-28). A total of 35 studies (70%) were published between 2000 and 2010. The citation rate of the 16 most recent studies was almost double that of the 16 oldest studies (17.5 vs 9.9; P <.001). Nineteen studies (49%) were classified as having poor quality (mCMS <50 points). The mean JIF of the 9 journals that published the studies was 5.1. The citation rate correlated with the number of citations (r = 0.56; P <.001), publication year (r = 0.60; P <.001), and LoE (r = –0.44; P =.005). The publication year correlated with the LoE (r = –0.40; P =.01). Study quality in terms of mCMS correlated with the JIF (r = 0.35; P =.03) and LoE (r = –0.48; P =.003) but not the citation rate (P =.15). Conclusion: The mean LoE and the citation rate of the most cited articles on Achilles tendon injury both significantly increased over time. Although the JIF was positively correlated with study quality, almost half of the studies had poor-quality methodology. [ABSTRACT FROM AUTHOR]

Introduction Military training that increases physical stress on musculoskeletal morphology also increases the risk of orthopedic injuries. Somatosensory prevention programs that reduce stress and improve functionality could be beneficial for better organization of tendon structure. The aim of this study was to investigate the impact of a somatosensory prevention exercise on the tendon structure (percentage of echo-type fibers; A-P and M-L diameters and cross-sectional area) of the Achilles tendon and patellar tendon among combat soldiers. Materials and Methods These tendons of male Infantry soldiers aged 18-21 were screened before and after a 14-week training course. The intervention group, who performed preventative exercises, included 108 soldiers (BMI = 23.85 ± 2.76), while the control group, who participated in the same military course without these exercises, included 98 soldiers (BMI = 24.26 ± 4.03). Ultrasound scanning for tendon structure included percent of echo-type I-IV fibers, A-P diameter, M-L diameter, and cross-sectional area parameters. Results Time by group interaction was found for echo-type I and II in both tendons. No significant differences were found between the two groups in the pretesting percentage of echo-type IV fibers of the Achilles tendon (P  = .522), in echo-type III fibers of the Achilles tendon (P  = .833), and echo-type IV fibers of the patellar tendon (P  = .162). Greater pre-post differences in echo-type III and IV fibers were found in the control group compared with the intervention group for both the Achilles tendon (P  = .021, P  = .002) and the patellar tendon (P  < .001, P  < .001). Conclusion Increased damaged fibers (echo-type III and IV) of both tendons were found among the control group, yet not among soldiers who performed prevention exercises. [ABSTRACT FROM AUTHOR]

Severe flexible flatfeet with triceps surae complex shortening are prognostically unfavorable in early childhood and may compromise normal foot development. This retrospective, IRB-approved study included 20 children (38 feet) under 6 years with severe flexible flatfeet and triceps surae complex shortening. Treatment included minimally invasive percutaneous achilles tendon lengthening followed by a 4-week cast fixation and corrective orthotic therapy under talo-navicular reposition for at least 6-months. Preoperative weightbearing x-rays and at the last available follow-up included anteroposterior talus-first metatarsal angle and lateral talus pitch, Meary's and talocalcaneal angle and were compared to reference values. ROM, surgeon-rated clinical outcomes and complications/re-interventions were evaluated. Age at surgery was 3.7 years (1.3–5.9 y) and follow-up time was 4.3 years (1.1–8.9 y). No complications occurred. Clinical outcome was good (68 %) to very good (26 %). Ratio of normal angles increased significantly for three angles. Dorsiflexion ROM improved from −5.0 ± 6.8° at baseline to 15.7 ± 7.6°. With significant improvements in clinical and radiographic outcomes, minimal-invasive percutaneous Achilles tendon lengthening followed by orthotic therapy seems to be a valuable treatment option for selected preschool-aged patients with severe, flexible flatfeet with significantly shortened triceps surae. IV [ABSTRACT FROM AUTHOR]

Individual treatment selection has been proposed as the key to optimized treatment. The purpose was to investigate if treatment selection using the individualized treatment algorithm Copenhagen Achilles Rupture Treatment Algorithm (CARTA) differs between patients treated as usual regarding gait dynamics and tendon elongation. The patients were randomized to one of three parallel groups: 1) intervention group: participants treated according to CARTA, 2) control group: participants treated non-operatively, 3) control group: participants treated operatively. The primary outcome was ankle peak power during push off during walking at 12 months. 156 patients were assessed for eligibility. 21 were allocated to the intervention group, and 20 and 19 to the control groups. The results indicated no statistically significant differences between the intervention group and the control groups. Individualized treatment selection based on CARTA did not demonstrate less affected gait dynamics or less tendon elongation than patients treated as usual. [ABSTRACT FROM AUTHOR]

Background and purpose -- Data on incidence and on trends in treatment of hamstring injuries, including proximal hamstring tendon avulsions (PHA), is limited. We aimed to investigate the incidence, trends in operative treatment, age, and sex distribution of hamstring injuries in Sweden between 2001 and 2020. Patients and methods -- We obtained data recorded in the National Patient Register between 2001 and 2020 on patients between 18 and 90 years of age, with the ICD-10 code S76.3, to calculate the incidence of patients treated operatively for hamstring injuries in Sweden. Patients with the NOMESCO classification NFL49 were considered as having been treated operatively. Data on quadriceps and Achilles tendon injuries were obtained for comparison. To calculate incidences, adult population data for every year were obtained from the Statistics Sweden website. Results -- The incidence of patients diagnosed with hamstring injuries increased from 2.2 to 7.3 per 100,000 person-years. There was a rising trend of surgical treatment per diagnosed case from 3.0% to 14.2%. Patients diagnosed in units with the highest experience of surgical treatment of hamstring injuries tended to be operated on more often (22.2%) than patients diagnosed in units with limited experience (5.1%), although the fraction of operated patients was increasing in both groups. Conclusion -- Between 2001 and 2020 there was an increase in the proportion of operatively treated hamstring injuries. [ABSTRACT FROM AUTHOR]

Calcaneus fractures make up only 2% of all fractures, and tongue-type calcaneus fractures represent 25-40% of all calcaneus fractures. While rare, tongue-type calcaneus fractures can put the superficial soft tissue at risk for necrosis and other complications, creating a surgical emergency. This case report describes the care of a patient who presented to a remote island critical-access emergency room after a fall from height. He described severe, sharp pain in the heel and was found to have tenting and blanching of the overlying skin near the injury. These findings suggested the soft tissues were at high risk for necrosis if not treated immediately. An X-ray confirmed a tongue-type calcaneus fracture. The patient was splinted in plantar flexion and transported by helicopter to a mainland hospital capable of performing the appropriate surgical reduction. The patient underwent open reduction internal fixation of the calcaneus, relieving pressure on the skin. He tolerated the procedure well, and there were no complications. He was discharged the day after surgery with outpatient follow-up. His case was prolonged and required multiple procedures to ultimately achieve appropriate healing. This case illustrates the importance of recognizing fractures presenting with skin involvement since surgical emergencies require prompt intervention to reduce the risk of serious complications such as open fracture from skin breakdown, poor healing, and a slow return to normal activities. It also emphasizes the importance of advocating for expedient patient care to increase the odds of a good outcome and ensure patients are given high-quality care. Topics: Calcaneus fracture, tongue-type calcaneus fracture, fall from height, axial loading, fracture complications, case report. [ABSTRACT FROM AUTHOR]

Background: Deficits in calf muscle function and heel-rise performance are common after an Achilles tendon rupture (ATR) and are related to tendon elongation and calf muscle atrophy. Whether early functional mobilization (EFM) can improve calf muscle function compared with standard treatment (ST) with 2 weeks of immobilization and unloading in a plaster cast is unknown. Hypothesis: EFM would lead to superior recovery of heel-rise performance, as demonstrated by more symmetrical side-to-side ankle and knee joint kinematics, compared with ST. Study Design: Cohort study; Level of evidence, 2. Methods: In total, 47 patients with an ATR were prospectively included and treated with open surgical repair and randomized 2:1 postoperatively to either EFM or ST. Overall, 29 patients were treated with a dynamic orthosis (EFM), and 18 underwent ST. At 8 weeks and 6 months after ATR repair, 3-dimensional motion analysis of heel-rise performance was conducted. At 6 months, tendon length and muscle volume were assessed with ultrasound imaging, calf muscle function with the heel-rise test, and patient-reported outcomes with the Achilles tendon Total Rupture Score. Results: At 8 weeks and 6 months, there were no significant group differences between the EFM and ST groups in heel-rise performance, but significant side-to-side differences in ankle and knee kinematics were detected. At 8 weeks and 6 months, both the EFM and ST groups showed a significantly decreased peak ankle plantarflexion angle and increased knee flexion angle on the injured limb compared with the uninjured limb during bilateral heel raises. Linear regression demonstrated that greater atrophy of the medial gastrocnemius muscle (P =.008) and higher body weight (P <.001) were predictors of a decreased maximum peak ankle plantarflexion angle on the injured limb at 6 months. Conclusion: EFM after an ATR repair did not lead to superior recovery of calf muscle function, as assessed by heel-rise performance, compared with ST. Increased knee flexion seemed to be a compensatory strategy for decreased ankle plantarflexion. Medial gastrocnemius atrophy and increased body weight were additional factors associated with a decreased ankle plantarflexion angle. Registration: NCT02318472 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Orthoses are an important part of both conservative and operative treatment of acute Achilles tendon rupture as they can be used to position the foot in equinus and protect the torn tendon from strain in the healing phase. The aim of the study was to test four different orthoses ability to position the foot in equinus. The study was performed as a cross-sectional study. 15 healthy study participants underwent radiographic examination with 11 true lateral radiographs of the right ankle and foot, one with the ankle joint in neutral position; one of a circular equinus cast (CEC); three of an adjustable equinus boot (AEB) with the foot in 30°, 15°, and 0° of plantar flexion, respectively; three of a fixed angle orthosis with 1, 2, and 3 wedges with a plateau (WWP); and three of a fixed angle orthosis with 1, 2, and 3 wedges without plateau (WWOP). The primary outcome was the Achilles Relief Distance (ARD). Secondary outcomes were the tibiocalcaneal angle (TCA), the tibiotalar angle (TTA), and the tibio- 1st metatarsal angle (1MTP). All measurements were performed by a radiologist. The mean (SD) ARD was 11 mm (7) in CEC, 23 mm (6) with 3 WWP, 11 mm (5) with 3 WWOP, and 15 mm (5) using AEB in 30° of plantarflexion. The mean (SD) TCA was 86° (7,8) in CEC, 76° (7,3) with 3 WWP, 90° (6,9) with 3 WWOP, and 84° (6,6) using the AEB in 30° of plantarflexion. CEC, AEB, and WWOP showed statistically significantly larger plantarflexion than WWP. CEC, AEB and WWOP produced significantly greater plantarflexion compared to WWP. [ABSTRACT FROM AUTHOR]

Context: It has been reported that there is a high rate of Achilles tendon injury among kendo athletes. For protection and to support the area, kendo athletes habitually use taping during practice or games. Objective: To investigate the effect of various taping techniques on injury prevention and functional performance in kendo athletes. Design: Case-control study. Setting: Laboratory. Participants: 15 University Kendo Team athletes with at least 2 y kendo experience. Main Outcome Measures: Athletes completed 5 stepping backwards and striking cycles under 4 taping conditions: no taping, athletic taping of ankle joint (AT-Ankle), athletic taping of Achilles tendon (AT-Achilles), and Kinesio-Tex taping of Achilles tendon (KT-Achilles). Jump distance, lower limb angular motion, left foot-ground contact time, Achilles tendon force (ATF), and soleus and medial gastrocnemius muscle activities were measured. Results: Lowest peak ATF was found in AT-Achilles during heel-down phase, with statistically significant difference from KT-Achilles peak force. Significant decline of soleus muscle electromyography amplitude was also found when compared to no taping during heel-down phase and other conditions during pushing phase. Conversely, KT-Achilles showed significant decrease in foot-ground contact time compared with no taping and greater ankle range of motion than in AT-Ankle. Conclusion: To protect the Achilles tendon, AT-Achilles taping is recommended since it tends to decrease ATF. Conversely, to enhance athlete performance, we recommend KT-Achilles taping to speed up kendo striking motion. However, the Achilles tendon must withstand greatest forces concurrently. This finding implies that AT-Achilles taping can protect the injured Achilles tendon and KT-Achilles taping can enhance performance on the kendo striking motion. [ABSTRACT FROM AUTHOR]

Background: The preseason is a crucial time period for professional athletes to prepare for the upcoming season. However, due to the coronavirus 2019 (COVID-19) pandemic, the 2020 National Football League (NFL) preseason was canceled. As the regular season progressed, an increased number of injuries became apparent. Purpose/Hypothesis: The purpose of this study was to compare injury rates between the 2019 and 2020 NFL regular seasons after the canceled 2020 preseason. It was hypothesized that injury rates in the 2020 season would be the same or higher compared with 2019. Study Design: Descriptive epidemiology study. Methods: A public database of all 32 NFL teams was used to examine the movement of all players to injured reserve status as well as every player who missed a regular-season game due to injury for both the 2019 and the 2020 NFL regular seasons. Data collection consisted of tallying the total number of reported musculoskeletal injuries for each team. Comparisons of injury rates between the 2 seasons were made using a Wilcoxon signed-rank statistical analysis. Results: The total number of musculoskeletal injuries was 632 for the 2019 regular season and 765 for the 2020 regular season (P =.0324). Compared with 2019, statistically significant increases in injury rates in 2020 were seen for calf or Achilles tendon strain (17 vs 39; P =.009), groin injury (25 vs 46; P =.018), and anterior cruciate ligament tear (14 vs 29; P =.016). There were several other increased trends in soft tissue injury rates in the 2020 season (eg, hamstring injury [87 vs 114; P =.085]); however, these did not reach statistical significance. Conclusion: This study showed a significant increase in total injuries during the 2020 COVID-19-affected NFL regular season compared with 2019. Several major soft tissue injuries reached statistical significance in their increase from 2019 to 2020 after the cancellation of the 2020 preseason due to COVID-19. These findings suggest that organized team preseason training and conditioning could have an effect on the prevention of sport-related injury at the highest level. [ABSTRACT FROM AUTHOR]

Background. Scarless healing comprises the ultimate goal after an injury. Since tendon healing results in a fibrotic scar, an injured tendon can never regain the mechanical potential and strength of its uninjured form. A wide variety of studies focus on the tendon healing with an absent or minimal peritendinous adhesions. However, no simple method has managed it at all. Possible complex actions and peritendinous environmental events take place during the tendon healing process. Tamoxifen (TAM), besides its breast cancer-related usage, is a potent antifibrotic drug. Here, we aimed to reduce the peritendinous adhesion with TAM administration. Methods. Achilles tendons of 44 Wistar albino rats were randomly distributed in 4 groups. In group 1, bilateral lower extremities were used as control and sham. Groups 2 and 3 were comprised of low-dose (1 mg/kg) and high-dose (40 mg/kg) systemic administration of TAM, respectively. Group 4 included local administration (1 mg/kg) of TAM. Biomechanical, macroscopical, and histopathological analyses were done and compared statistically. Biomechanically, the maximum force that led to tendon rupture was determined, and tensile force data were recorded via tensile testing device. Macroscopical and histopathological analysis were composed of the quantity, quality, and grade of peritendinous adhesions. Results. Macroscopic and histopathologic findings revealed that groups 2 and 3 had a variety of values ranging between slight to severe adhesions. In group 2, almost half of the animals had moderate adhesions, whereas in group 3, the majority of the animals had moderate adhesions. There were no animals with moderate or severe adhesions in group 4. Statistically significant values were calculated between sham and control groups. Biomechanically, group 2 showed the most significant result. The tendons in group 2 had the highest stiffness when maximal force was applied to rupture the tendons. Henceforth, all these consequences were proven statistically. Conclusion. We achieved less peritendinous adhesion with the local administration of TAM when compared to systemic administration of TAM. A better understanding of the peritendinous environmental process will reveal to develop new therapies in the prevention of peritendinous adhesions. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the positional relationship between protective channel and sural nerve while treating acute Achilles tendon rupture with channel assisted minimally invasive repair (CAMIR) technique based on anatomical observations of cadaver specimens., Methods: Twelve adult cadaveric lower limb specimens (6 left, 6 right) were utilized. A CAMIR device was implanted at a distance of 4 cm from the proximal end of the specimen to the Achilles tendon insertion. The skin was incised along the tendon's medial side, the sural nerve was dissected, and the positional relationship with the protective channel was observed. The distance from the sural nerve-Achilles tendon intersection to the calcaneal insertion, the vertical distance between protective channel and the calcaneal insertion, and the horizontal distance between the sural nerve and protective channel were measured by using vernier caliper., Results: Anatomical examination demonstrated a variable positional relationship between the sural nerve and protective channel, with the sural nerve positioned above (8 specimens) or below (4 specimens) the protective channel. The distance from the sural nerve-Achilles tendon intersection to the calcaneal insertion was (105.67±14.94) mm, the vertical distance between protective channel and the calcaneal insertion was (93.20±9.57) mm, and the horizontal distance between the sural nerve and protective channel was (0.31±0.14) mm., Conclusion: The use of CAMIR technique for the treatment of acute Achilles tendon rupture can effectively avoid iatrogenic injury to the sural nerve.

Objective: To investigate the anti-adhesive effect and underlying mechanism of dynamic and static stress stimulation on the early healing process of rat Achilles tendon injury., Methods: Achilles tendon tissues of 15 male Sprague Dawley (SD) rats aged 4-6 weeks were isolated and cultured by enzyme digestion method. Rat Achilles tendon cells were treated with tumor necrosis factor α to construct the Achilles tendon injury cell model, and dynamic stress stimulation (dynamic group) and static stress stimulation (static group) were applied respectively, while the control group was not treated. Live/dead cell double staining was used to detect cell activity, ELISA assay was used to detect the expression of α smooth muscle actin (α-SMA), and real-time fluorescence quantitative PCR was used to detect the mRNA expression of collagen type Ⅰ (COL1A1), collagen type Ⅲ (COL3A1), and Scleraxis (SCX). Thirty male SD rats aged 4-6 weeks underwent Achilles tendon suture and were randomly divided into dynamic group (treated by dynamic stress stimulation), static group (treated by static stress stimulation), and control group (untreated), with 10 rats in each group. HE staining and scoring were performed to evaluate the healing of Achilles tendon at 8 days after operation. COL1A1 and COL3A1 protein expressions were detected by immunohistochemical staining, α-SMA and SCX protein expressions were detected by Western blot, and maximum tendon breaking force and tendon stiffness were detected by biomechanical stretching test., Results: In vitro cell experiment, when compared to the static group, the number of living cells in the dynamic group was higher, the expression of α-SMA protein was decreased, the relative expression of COL3A1 mRNA was decreased, and the relative expression of SCX mRNA was increased, and the differences were all significant ( P <0.05). In the in vivo animal experiment, when compared to the static group, the tendon healing in the dynamic group was better, the HE staining score was lower, the expression of COL1A1 protein was increased, the expression of COL3A1 protein was decreased, the relative expression of SCX protein was increased, the relative expression of α-SMA protein was decreased, and the tendon stiffness was increased, the differences were all significant ( P <0.05)., Conclusion: Compared with static stress stimulation, the dynamic stress stimulation improves the fibrosis of the scar tissue of the rat Achilles tendon, promote the recovery of the biomechanical property of the Achilles tendon, and has obvious anti-adhesion effect.

Introduction: Tendon injuries present a significant challenge for independent repair, and can progress into tendinopathy over time, highlighting the importance of early intervention. Dendritic cell-derived exosomes (DEXs) has been shown to shift the polarization of M1 macrophages, the predominant inflammatory cells in the early stages of tendon injury. This study introduces a therapeutic approach that effectively manages inflammation while promoting regeneration in the treatment of tendinopathy., Methods: The purification and characterization of DEXs were meticulously conducted. Experiments were carried out using an Achilles tendon rupture mouse model, with weekly DEXs treatment starting on postoperative day (POD) 4. In vitro, the function of DEXs was assessed by coculturing them with tendon stem/progenitor cells (TSPCs) in culture medium containing IL-1β. Tendon healing progress was evaluated using Sirius Red staining, Masson's trichrome staining, biomechanical testing, and immunofluorescence microscopy. The inflammatory microenvironment of injured tendons was evaluated using the Luminex procedure and flow cytometry analysis., Results: DEXs treatment significantly enhanced tendon cell differentiation, promoted collagen type I synthesis, and inhibited collagen type III synthesis, thereby expediting tendon healing. Furthermore, DEXs treatment improved the inflammatory microenvironment by reducing multiple cytokines (IL-1β, IL-4, IL-6, TNF-α, and IFN-γ) and induced the conversion of M1 macrophages to M2 macrophages by activating the PI3K/AKT pathway., Conclusion: DEXs demonstrated a potent ability to promote tendon healing while ameliorating the inflammatory microenvironment, suggesting their potential as a therapeutic approach to prevent the development of tendinopathy., Competing Interests: The authors declare that they have no competing interests in this work., (© 2024 Chen et al.)

Background: People with Achilles tendinopathy (AT) experience persistent pain that can limit engagement with daily occupations and negatively impact mental health. Current therapeutic exercise approaches vary in success, with many people experiencing reinjury, leading to a cycle of chronic tendinopathy often lasting years. High-magnitude precision loading may help people exit this feedback cycle, but applying these principles clinically is challenging., Objective: This user-centered design case study aims to provide an overview on how the PhysViz (a prototype for a novel remote rehabilitation intervention for AT management) was developed and evaluated following the development phase of the Framework for Accelerated and Systematic Technology-Based Intervention Development and Evaluation Research (FASTER)., Methods: The development process engaged a multidisciplinary team comprising people with AT experiences, clinicians, and engineers. It followed the 5 stages within the FASTER development phase: empathize, define, ideate, prototype, and test. The PhysViz development and evaluation were informed by needs assessments, surveys, literature reviews, validation studies, case studies, roundtable discussions, and usability testing (some of which have been published previously). The FASTER systematically guided the integration of evidence-based features and behavior change theory., Results: By using the FASTER and ensuring that the PhysViz system was underpinned by diverse stakeholder needs, this work resulted in the development of a working prototype for both the PhysViz physical exercise tool and the accompanying PhysViz software package (mobile app and web application). A variety of study designs informed user-desired features that were integrated into the PhysViz prototype, including real-time biofeedback in the form of precision load monitoring, customizable exercise programs, and pain tracking. In addition, clinicians can visualize client data longitudinally and make changes to client exercise prescriptions remotely based on objective data. The identified areas for improvement, such as upgrading the user interface and user experience and expanding clinical applications, provide valuable insights for future PhysViz iterations. Further research is warranted to assess the long-term efficacy and feasibility of the PhysViz in diverse clinical settings and its potential to improve AT symptoms., Conclusions: Being one of the first technology development initiatives guided by the FASTER, this study exemplifies a systematic and multidisciplinary approach to creating a remote rehabilitation intervention. By incorporating stakeholder feedback and evidence-based features, the PhysViz addresses key challenges in AT rehabilitation, offering a novel solution for precision loading and therapeutic exercise engagement. Positive feedback from users and clinicians underscores the potential impact of the PhysViz in improving AT management outcomes. The PhysViz serves as a model for technology-based intervention development, with potential implications for other tendinopathies and remote rehabilitation strategies., (©Kohle Merry, Megan M MacPherson, Jackie L Whittaker, Christopher Napier, Liisa Holsti, Alex Scott. Originally published in JMIR Human Factors (https://humanfactors.jmir.org), 13.11.2024.)

» Platelet-rich plasma and hyaluronic acid are low-risk and potentially high-reward treatments for Achilles tendinopathy, although clinical studies have yielded mixed results with questionable methodological quality» Case series and reports have reported that bone marrow aspirate, stem cells, and amniotic membrane products can improve functional outcomes, alleviate pain, and facilitate return to sport and activities, but high-level evidence studies are lacking» Exosomes are a promising novel biologic with laboratory studies showing improved collagen organization and cell proliferation, greater tendon mechanical properties, and prevention of extracellular matrix breakdown.» Standardization of protocols with clear reporting is necessary for future studies evaluating orthobiologic therapies for Achilles tendon injuries., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSREV/B170)., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: It has been reported that 43.6% of ankle fractures are accompanied by posterior malleolus fractures. The aim of this study is to define a safe zone for posterior malleolus fractures by determining the locations of the important anatomical structures in this region. Additionally, it aims to identify the trans-Achilles passage line for Kirschner wire insertion through a posteroanterior approach for posterior malleolus fragments., Methods: Six below-knee amputee fresh-frozen leg cadavers were used in this study. A trans-Achilles Kirschner wire was applied to the cadavers in the posteroanterior direction under the guidance of fluoroscopy. The areas where the Kirschner wire passed were dissected, and their proximity to vital anatomical structures was measured., Results: In all cadavers, the transverse thickness of the Achilles tendon at the level of the trans-Achilles Kirschner wire was 15.5 mm and the trans-Achilles Kirschner wire application was 18.6 mm from the sural nerve, 16 mm from the posterior tibial tendon, and 12.16 mm from the flexor digitorum longus muscle. It was performed 15.16 and 14.6 mm from the posterior tibial artery and vein, 12.3 mm from the tibial nerve, 13.6 mm from the tibiofibular joint, and 55.5 mm from the insertion site of the Achilles tendon to the calcaneus and at a sufficient distance from vital anatomical structures., Conclusions: The proposed trans-Achilles percutaneous surgical technique is safe from neurovascular structures for fixing posterior malleolar fractures. However, the long-term clinical outcomes of this technique need to be explored., Level of Evidence: Level III, A cadaveric study., (© 2024. The Author(s).)

Aims: Venous thromboembolism (VTE) is a potential complication of foot and ankle surgery. There is a lack of agreement on contributing risk factors and chemical prophylaxis requirements. The primary outcome of this study was to analyze the 90-day incidence of symptomatic VTE and VTE-related mortality in patients undergoing foot and ankle surgery and Achilles tendon (TA) rupture. Secondary aims were to assess the variation in the provision of chemical prophylaxis and risk factors for VTE., Methods: This was a multicentre, prospective national collaborative audit with data collection over nine months for all patients undergoing foot and ankle surgery in an operating theatre or TA rupture treatment, within participating UK hospitals. The association between VTE and thromboprophylaxis was assessed with a univariable logistic regression model. A multivariable logistic regression model was used to identify key predictors for the risk of VTE., Results: A total of 13,569 patients were included from 68 sites. Overall, 11,363 patients were available for analysis: 44.79% were elective (n = 5,090), 42.16% were trauma excluding TA ruptures (n = 4,791), 3.50% were acute diabetic procedures (n = 398), 2.44% were TA ruptures undergoing surgery (n = 277), and 7.10% were TA ruptures treated nonoperatively (n = 807). In total, 11 chemical anticoagulants were recorded, with the most common agent being low-molecular-weight heparin (n = 6,303; 56.79%). A total of 32.71% received no chemical prophylaxis. There were 99 cases of VTE (incidence 0.87% (95% CI 0.71 to 1.06)). VTE-related mortality was 0.03% (95% CI 0.005 to 0.080). Univariable analysis showed that increased age and American Society of Anesthesiologists (ASA) grade had higher odds of VTE, as did having previous cancer, stroke, or history of VTE. On multivariable analysis, the strongest predictors for VTE were the type of foot and ankle procedure and ASA grade., Conclusion: The 90-day incidence of symptomatic VTE and mortality related to VTE is low in foot and ankle surgery and TA management. There was notable variability in the chemical prophylaxis used. The significant risk factors associated with 90-day symptomatic VTE were TA rupture and high ASA grade., Competing Interests: J. Mangwani reports support from the Leicester Hospitals Charity, related to this study. J. Mangwani reports payment or honoraria for lectures, presentations, educational events from Orthosolutions, and royalties from Meshworks, unrelated to this study. K. Malhotra reports payment or honoraria for lectures, presentations, speaker bureaus, manuscript writing or educational events from NewClip Technics, unrelated to this study. L. W. Mason reports royalties or licenses, consulting fees, and patents planned, issued or pending from Orthosolutions, unrelated to this study., (© 2024 The British Editorial Society of Bone & Joint Surgery.)

Background: Gradual-onset Achilles tendon injuries (GoATIs) in runners are common. Data show that chronic diseases are associated with GoATI., Objective: To determine risk factors associated with a history of GoATIs among long-distance runners (21.1 and 56 km) entering a mass community-based running event., Methods: Online pre-race medical screening questionnaire data from 76,654 consenting Two Ocean Marathon race entrants (71.8% entrants) were collected prospectively over 4 years (2012-2015); this cross-sectional study is a retrospective analysis of these data. A total of 617 entrants (0.8%) reported a GoATI in the last 12 months; 60,635 entrants reported no history of any running injury (controls). Categories of factors associated with GoATI were explored (univariate and multiple regression analyses): demographics (age group, sex, race, distance), training/racing history, and history of allergy, history of chronic disease, and Composite Chronic Disease Score. Prevalence and prevalence ratios (PRs; 95% CI) are reported., Results: Factors associated with a higher prevalence of a history of GoATI (univariate analysis vs. controls) were older age (>31 years) (p < .001), male sex (PR = 1.76; p < .001), and longer race distance (56 km vs. 21.1 km) (PR = 2.06; p < .001). Independent factors associated with a history of GoATI (multiple regression) were increased years of recreational running (PR = 1.17 for every 5-year increase, p < .001), higher Composite Chronic Disease Score (PR = 2.07 for every 2-unit increase, p < .001), and allergy history (PR = 1.98 p < .001)., Conclusion: Novel independent factors associated with a history of GoATI in distance runners were increased years of recreational running, chronic disease history, and allergy history. Runners at risk for GoATI could be targeted for injury prevention interventions. Future studies should focus on establishing a causal relationship., (© 2024 The Authors. PM&R published by Wiley Periodicals LLC on behalf of American Academy of Physical Medicine and Rehabilitation.)

Background: Pickleball's surging popularity has driven an increase in injuries presenting to medical providers. This study seeks to describe the epidemiology of pickleball foot and ankle injuries including patient demographics, diagnoses, and mechanism of injury., Methods: A retrospective review from our institutional database identified patients treated in the foot and ankle clinic whose medical records included the search terms "pickleball" and "pickle ball." Only injuries sustained while playing pickleball were included. Patient demographics, diagnosis, mechanism of injury, and treatment were collected. Injury incidence and descriptive analyses were calculated., Results: A total of 198 patients with pickleball foot and ankle injuries were identified. The incidence of injuries increased 6.5-fold from 2019 to 2023. The mean age of patients was 58.3 years (SD = 12.2). Most patients were male (58.6%) and reported a traumatic injury (77.8%). The most common diagnosis was Achilles tendon rupture (39.4%). The most common mechanisms of injury were running or lunging forward (30.9%), planting the foot (16.5%), and inverting the foot and ankle (15.5%). Most injuries were treated nonoperatively (71.2%); however, 62.8% of Achilles tendon ruptures were treated surgically., Conclusion: The incidence of pickleball foot and ankle injuries increased dramatically from 2015 to 2023. Injuries occurred more frequently in older, male patients, with Achilles tendon rupture being the most common diagnosis., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Disclosure forms for all authors are available online.

It has been demonstrated in a number of studies that high levels of uric acid can cause crystal deposition in the tendons of the lower extremities, which in turn can impair the Achilles tendon. This study aimed to interpret whether hyperuricemia is relevant with Achilles tendon rupture. Patients diagnosed with Achilles tendon rupture at the same institution between 2013 and 2022 were included in the case group. Healthy subjects who had physical examinations during the same period were included in the control group. Propensity score matching was used to match in a 1:1 ratio. Demographic and clinical characteristics of patients in both groups were compared. Five hundred and fourteen patients were included in the study (ATR=257; Control group=257). The proportion of individuals with hyperuricemia varied significantly between the 2 groups (Achilles tendon rupture group=43.6%; control group=27.6%; p<0.001). The Achilles tendon rupture and hyperuricemia were linked by conditional logistic regression (p<0.001; OR=2.036; 95CI%=1.400-2.961). Compared with healthy subjects, patients with hyperuricemia have a higher risk of Achilles tendon rupture. Further studies are required to verify the effects of hyperuricemia and monosodium urate crystals on Achilles tendon structure., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Alkaptonuria (AKU) is a rare hereditary disease. Ochronotic arthropathy, tendinopathy, and osteopenia/osteoporosis are generally musculoskeletal manifestations in patients with AKU. Because of the ochronotic tendinopathy and osteopenia, the surgical strategy for chronic ochronotic Achilles tendon rupture may be challenging. No studies have reported the surgical treatment of chronic Achilles tendon rupture in patients with AKU., Case Presentation: We report a case of AKU that required surgical treatment for chronic Achilles tendon rupture. A 60-year-old woman was referred to our department for the assessment of left hindfoot pain that persisted for more than nine months after an ankle sprain. Three years prior to the first presentation to our hospital, she was diagnosed with AKU due to pigmented hip cartilage at the time of total hip arthroplasty. The patient was diagnosed as chronic Achilles tendon rupture based on the results of physical examination and magnetic resonance imaging (MRI). The MRI showed enlarged scar tissue of the Achilles tendon with an intrasubstance high signal intensity. We performed resection of the central part of the scar tissue (total length, 24 mm) followed by direct repair using the proximal and distal stumps of the scar tissue. The MRI at 12months after surgery showed continuity of the repaired Achilles tendon. At 18 months after surgery, the Achilles Tendon Total Rupture Score improved from 22 points preoperatively to 84 points postoperatively. The foot and ankle outcome score also improved., Conclusions: We reported a case of AKU with chronic Achilles tendon rupture in which direct repair using scar tissue between the tendon stumps was effective. Careful selection of the surgical procedure for the treatment of chronic ochronotic Achilles tendon rupture is recommended because of concomitant ochronotic tendinopathy and osteopenia/osteoporosis., (© 2024. The Author(s).)

Background: Skeletal muscle is a highly adaptive tissue, capable of responding to different physiological and functional demands, even in situations that may cause instability., Objectives: To evaluate how partial calcaneal tendon (CT) injuries affect the remodeling and plasticity of the gastrocnemius muscle over time., Methods and Results: The study was carried out with Wistar rats randomly divided into five groups. The control group comprised animals not subjected to partial CT damage. The remaining four groups were subjected to partial CT damage and were further categorized based on the time of euthanasia: 3, 14, 28, and 55 days after injury. The gastrocnemius muscle was collected and used for gene expression analysis, zymography, flow cytometry, and morphology. The calcaneal tendon was analyzed only to verify the presence of the partial injury., Results: The impact of partial CT injury on the gastrocnemius homeostasis, particularly on gene expression, was more pronounced in the 3-day group compared to the other groups, especially the control group. Cytokine profile and morphologic alterations occurred in the 55 days group when compared to the other groups., Conclusions: The data reported here suggest that partial injury can negatively affect intracellular signaling and degradation pathways, disturbing the muscular extracellular matrix regulatory mechanisms and communication with the tendon. However, skeletal muscle seems to mitigate these harmful effects in comparison with lesions that affect muscle and tendon., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Tendon healing involves mechanosensitive cells that adapt to mechanical stimuli through mechanotransduction, resulting in increased tissue strength. However, detailed insights into this process in response to different loads remain limited. We aimed to investigate how different loading regimes impact the spatial composition of elastin and collagens during Achilles tendon healing. Histological analysis was conducted on healing rat Achilles tendons exposed to (1) full loading, (2) reduced loading, or (3) minimal loading. Histological analysis included Hematoxylin & Eosin and immunohistochemical staining targeting elastin, Collagen 1, Collagen 3, and CD31. Our results showed that the impact of mechanical stimuli on healing tendons varied with the degree of loading. Unexpectedly, minimal loading led to higher staining intensity for collagens and elastin. However, tendons exposed to minimal loading appeared thinner and exhibited a less organized matrix structure, with fewer, less aligned, and more rounded cells. Additionally, our findings indicated an inverse correlation between angiogenesis and load level, with more blood vessels in tendons subjected to less loading. Tissue integrity improved by 12 weeks post-injury, but the healing process continued and did not regain the structure seen in intact tendons even after 20 weeks. This study reveals a load-dependent effect on matrix alignment, cell density, and cell alignment., (© 2024. The Author(s).)

Case: We report the case of a 44-year-old man who sustained an Achilles tendon rupture with an associated trimalleolar fracture and traumatic peroneal dislocation of the left ankle after a snowboarding injury. These injuries have been surgically repaired; the patient has returned to all his activities 18 months after surgery., Conclusion: The possibility of such injuries occurring in combination should be considered. A thorough history, physical examination, and plain radiographs should be performed in higher energy trauma to the ankle. Additional diagnostic tests such as ultrasonography or magnetic resonance imaging may be used to supplement treatment., Levels of Evidence: Level 5., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/C446)., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Partial or complete rupture of the tendon can damage the collagen structure, resulting in the disruption of the electrical signal pathway. It is a great challenge to reconstruct the original electrical signal pathway of the tendon and promote the regeneration and functional recovery of defective tendon. In this study, carbon fiber-mediated electrospinning scaffolds were fabricated by wrapping conductive, high-strength, loose single-bundle carbon fibers with nanofiber membranes. Due to the presence of nanofiber membranes, the maximum tensile force of the scaffolds was 2.4 times higher than that of carbon fibers, while providing excellent temporal and spatial prerequisites for tenocytes to adapt to electrical stimulation to accelerate proliferation and expression. The diameter of the carbon fiber monofilaments used in this study was 5.07 ± 1.20 μm, which matched the diameter of tendon collagen, allowing for quickly establishing the connection between the tendon tissue and the scaffold, and better promoting the recovery of the electrical signal pathway. In a rabbit Achilles tendon defect repair model, the carbon fiber-mediated electrospinning scaffold was almost filled with collagen fibers compared to a nonconductive polyethylene glycol terephthalate scaffold. Transcriptome sequencing revealed that fibromodulin and tenomodulin expression were upregulated, and their related proteoglycans and glycosaminoglycan binding proteins pathways were enhanced, which could regulate the TGF-β signaling pathway and optimize the extracellular matrix assembly, thus promoting tendon repair. Therefore, the scaffold in this study makes up for the shortage of conductive scaffolds for repairing tendon defects, revealing the potential impact of conductivity on the signaling pathway of tendon repair and providing a new approach for future clinical studies.