OBJECTIVE: Surgical treatment of chronic Achilles tendon rupture is a technically challenging procedure. We aimed to compare the clinical outcomes, range of motion, and strength of ankle plantar- and dorsiflexors between two techniques for fixation of flexor hallucis longus tendon to the calcaneus: interference screw and suture-external button.
METHODS: Twenty-five patients participated in this retrospective comparative study. All patients underwent short harvest FHL tendon transfer for chronic AT rupture were asked for a follow-up visit, at least one year following surgery. The outcomes were evaluated by visual analog scale (VAS), AOFAS ankle-hindfoot score, and VISA-A questionnaire. Ankle ROM with possible restriction in addition to isokinetic strength of ankle plantar- and dorsiflexors was assessed.
RESULTS: No statistically significant difference was observed between the groups for pain (P = 0.81), AOFAS ankle-hindfoot scale (P = 0.97), and VISA-A (P = 0.44). Notably, more decrease in ankle dorsiflexion was seen in interference screw group in comparison with suture-external button group (4.4 ± 6.6 vs. 9.5 ± 6.1 degrees, P = 0.06). The difference of active dorsiflexion between operated and non-operated side in interference screw group was statistically significant (P = 0.02). Biotenodesis screw imposed more limb asymmetry in comparison with suture-external button technique.
CONCLUSIONS: Fixation of transcalcaneal FHL tendon transfer for chronic AT either by interference screw or suture-external button has encouraging postoperative clinical results. Although ROM of the ankle joint reduced in both techniques, interference screw may result in more reduction in dorsiflexion of the ankle.

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

OBJECTIVE: Tendon segmentation is crucial for studying tendon-related pathologies like tendinopathy, tendinosis, etc. This step further enables detailed analysis of specific tendon regions using automated or semi-automated methods. This study specifically aims at the segmentation of Achilles tendon, the largest tendon in the human body.
METHODS: This study proposes a comprehensive end-to-end tendon segmentation module composed of a preliminary superpixel-based coarse segmentation preceding the final segmentation task. The final segmentation results are obtained through two distinct approaches. In the first approach, the coarsely generated superpixels are subjected to classification using Random Forest (RF) and Support Vector Machine (SVM) classifiers to classify whether each superpixel belongs to a tendon class or not (resulting in tendon segmentation). In the second approach, the arrangements of superpixels are converted to graphs instead of being treated as conventional image grids. This classification process uses a graph-based convolutional network (GCN) to determine whether each superpixel corresponds to a tendon class or not.
RESULTS: All experiments are conducted on a custom-made ankle MRI dataset. The dataset comprises 76 subjects and is divided into two sets: one for training (Dataset 1, trained and evaluated using leave-one-group-out cross-validation) and the other as unseen test data (Dataset 2). Using our first approach, the final test AUC (Area Under the ROC Curve) scores using RF and SVM classifiers on the test data (Dataset 2) are 0.992 and 0.987, respectively, with sensitivities of 0.904 and 0.966. On the other hand, using our second approach (GCN-based node classification), the AUC score for the test set is 0.933 with a sensitivity of 0.899.
CONCLUSIONS: Our proposed pipeline demonstrates the efficacy of employing superpixel generation as a coarse segmentation technique for the final tendon segmentation. Whether utilizing RF, SVM-based superpixel classification, or GCN-based classification for tendon segmentation, our system consistently achieves commendable AUC scores, especially the non-graph-based approach. Given the limited dataset, our graph-based method did not perform as well as non-graph-based superpixel classifications; however, the results obtained provide valuable insights into how well the models can distinguish between tendons and non-tendons. This opens up opportunities for further exploration and improvement.

Recent studies combining high-density surface electromyography (HD-sEMG) and ultrasound imaging have yielded valuable insights into the relationship between motor unit activity and muscle contractile properties. However, limited evidence exists on the relationship between motor unit firing properties and tendon morpho-mechanical properties. This study aimed to determine the relationship between triceps surae motor unit firing properties and the morpho-mechanical properties of the Achilles tendon (AT). Motor unit firing properties (i.e. mean discharge rate (DR) and coefficient of variation of the interspike interval (COVisi)) and motor unit firing-torque relationships (cross-correlation between cumulative spike train (CST) and torque, and the delay between motor unit firing and torque production (neuromechanical delay)) of the medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SO) muscles were assessed using HD-sEMG during isometric plantarflexion contractions at 10% and 40% of maximal voluntary contraction (MVC). The morpho-mechanical properties of the AT (i.e. length, thickness, cross-sectional area and resting stiffness) were determined using B-mode ultrasonography and shear-wave elastography. Multiple linear regression analysis showed that at 10% MVC, the DR of the triceps surae muscles explained 41.7% of the variance in resting AT stiffness. Additionally, at 10% MVC, COVisi SO predicted 30.4% of the variance in AT length. At 40% MVC, COVisi MG and COVisi SO explained 48.7% of the variance in AT length. Motor unit-torque relationships were not associated with any morpho-mechanical parameter. This study provides novel evidence of a contraction-intensity dependent relationship between motor unit firing parameters of the triceps surae muscle and the morpho-mechanical properties of the AT.

Recent research shows that the functional outcome after an acute Achilles tendon rupture is comparable after conservative versus operative treatment. It is therefore recommended to treat patients conservatively, but strong reasons for surgical treatment exist. In principle, no additional radiographic diagnostic exams are indicated for the diagnosis. An appropriate anamnesis, palpable gap and positive Thompson test have an excellent sensitivity. In case of doubt, an ultrasound should be performed as the first step. A shared decision process should be pursued for establishing treatment plan. However, it is recommended that patients be treated conservatively unless strong arguments for surgical intervention are present. It is important to properly inform patients, and thus manage expectations about the expected rehabilitation process. If there is an increased risk of re-rupture, such as in athletes or during physically demanding work, surgical treatment can be considered. Then a surgical technique in which expertise and experience has been gained should be used as no difference in outcome have been found after open versus minimal invasive techniques.

BACKGROUND: The AGEs levels in tissues of diabetics and elderly tend to be higher than in normal individuals. This study aims to determine the effects of AGEs on Achilles tendon repair.
METHODS: Thirty-six male eight-week-old Sprague Dawley rats were selected in this study. The rats were randomly divided into two experimental groups and a control group after the transection of the Achilles tendon. During the tendon repair, the experimental groups were injected around the Achilles tendon with 350mmol/L (low dose group) and 1000mmol/L (high dose group) D-ribose 0.2 ml respectively to increase the AGEs level, while in the control group were given the same amount of PBS. The injections were given twice a week for six weeks. Collagen-I, TNF-α, and IL-6 expression in the healed Achilles tendon was assessed. Additionally, macroscopic, pathological, and biomechanical evaluations of Achilles tendon repair were conducted.
RESULTS: The repaired Achilles tendons in the high dose group showed severe swelling and distinctive adhesions. The histological score went up with the increase of the AGEs in the Achilles tendon (p<0.001). TNF- α and IL-6 in the Achilles tendon increased (p<0.001, p<0.001), and the production of collagen-I decreased with the accumulation of AGEs in the repaired Achilles tendon (p<0.001). The tensile strength of Achilles tendon in the high dose group was impaired significantly.
CONCLUSIONS: In current study, the compromised tendon repair model induced by AGEs was successfully established in rat. The study demonstrated that AGEs significantly impair Achilles tendon repair.

UNASSIGNED: The formation of adhesion after tendon injury represents a major obstacle to tendon repair, and currently there is no effective anti-adhesion method in clinical practice. Oxidative stress, inflammation, and fibrosis can occur in tendon injury and these factors can lead to tendon adhesion. Antioxidant carbon dots and ursolic acid (UA) both possess antioxidant and anti-inflammatory properties. In this experiment, we have for the first time created RCDs/UA@Lipo-HAMA using red fluorescent carbon dots and UA co-encapsulated liposomes composite hyaluronic acid methacryloyl hydrogel. We found that RCDs/UA@Lipo-HAMA could better attenuate adhesion formation and enhance tendon healing in tendon injury.
UNASSIGNED: RCDs/UA@Lipo-HAMA were prepared and characterized. In vitro experiments on cellular oxidative stress and fibrosis were performed. Reactive oxygen species (ROS), and immunofluorescent staining of collagens type I (COL I), collagens type III (COL III), and α-smooth muscle actin (α-SMA) were used to evaluate anti-oxidative and anti-fibrotic abilities. In vivo models of Achilles tendon injury repair (ATI) and flexor digitorum profundus tendon injury repair (FDPI) were established. The major organs and blood biochemical indicators of rats were tested to determine the toxicity of RCDs/UA@Lipo-HAMA. Biomechanical testing, motor function analysis, immunofluorescence, and immunohistochemical staining were performed to assess the tendon adhesion and repair after tendon injury.
UNASSIGNED: In vitro, the RCDs/UA@Lipo group scavenged excessive ROS, stabilized the mitochondrial membrane potential (ΔΨm), and reduced the expression of COL I, COL III, and α-SMA. In vivo, assessment results showed that the RCDs/UA@Lipo-HAMA group improved collagen arrangement and biomechanical properties, reduced tendon adhesion, and promoted motor function after tendon injury. Additionally, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the RCDs/UA@Lipo-HAMA group increased; the levels of cluster of differentiation 68 (CD68), inducible Nitric Oxide Synthase (iNOS), COL III, α-SMA, Vimentin, and matrix metallopeptidase 2 (MMP2) decreased.
UNASSIGNED: In this study, the RCDs/UA@Lipo-HAMA alleviated tendon adhesion formation and enhanced tendon healing by attenuating oxidative stress, inflammation, and fibrosis. This study provided a novel therapeutic approach for the clinical treatment of tendon injury.

UNASSIGNED: Surgical treatment of insertional Achilles tendinopathy (IAT) historically consists of Achilles tendon debridement with reattachment and excision of the posterosuperior calcaneal prominence with or without a gastrocnemius recession. Zadek osteotomy (ZO) is an alternative to an open midline splitting approach. The purpose of this study was to analyze patient-reported outcomes and complications after percutaneously performed ZO with minimum 2 years\' follow-up.
UNASSIGNED: One hundred eight cases treated with percutaneous ZO with a minimum 2-year follow-up were retrospectively reviewed. Postoperative complications and patient satisfaction were evaluated. Foot Function Index (FFI) and visual analog scale (VAS) scores were recorded at preoperative and follow-up appointments to measure patients\' functional outcomes and pain, respectively.
UNASSIGNED: Mean follow-up was 41.2 months (range, 24-65). Mean age was 51.8 years (range, 28-81). The mean FFI score improved from 56.1 (range, 47-88) to 11.0 (range, 7-59) postoperatively (P < .001). The mean VAS score improved from 7.7 (range, 5-10) to 0.4 (range, 0-7) postoperatively (P < .001). The overall complication rate was 3.8% (n = 4). Of 104 cases, 98.1% of patients said they were satisfied with their procedure (n = 102) when asked if they were satisfied with their ZO and recovery.
UNASSIGNED: We found the percutaneous ZO to be a safe and effective intervention for treatment of IAT. At a minimum of 2-year follow-up, this intervention is associated with minimal complications, improved function, reduced pain, and a high rate of patient satisfaction.

The production of triceps surae plantarflexion moment is complex in that the Achilles tendon moment arm affects the Achilles tendon force by determining the muscle length change and shortening velocity during ankle rotation. In addition, there is evidence for associations between the sizes of muscles and their moment arm at the joints they span. These relationships between muscle architecture and tendon moment arm ultimately affect the muscle\'s force generating capacity and are thus important for understanding the roles played by muscles in producing locomotion. The purpose of this study was to investigate in vivo the relationship between architecture of two plantarflexors and the Achilles tendon moment arm in a healthy adult population. Ultrasound-based measurements were made of the architecture (fascicle length, muscle volume, physiological cross-sectional area, and anatomical cross-sectional area) of the lateral and medial gastrocnemius and the Achilles tendon moment arm was assessed using a technique that combined ultrasound imaging and motion analysis. Positive correlations were observed between the length (r = 0.499, p = 0.049) and size variables (muscle volume r = 0.621, p = 0.010; ACSA r = 0.536, p = 0.032) of the lateral gastrocnemius and the Achilles tendon moment arm, but correlations were only observed for size variables (muscle volume r = 0.638, p = 0.008; PCSA r = 0.525, p = 0.037; ACSA r = 0.544, p = 0.029), and not the length, of the medial gastrocnemius. These findings suggest lateral gastrocnemius adapts to moment arms to maintain force production throughout the range of motion across individuals, while the medial gastrocnemius does not and is thus better suited for static force generation.

Background and Objectives: There is a lack of studies examining balance problems and Achilles tendon thickness in prediabetes despite their common occurrence in diabetes mellitus. The aim of this study was to evaluate Achilles tendon size and static and dynamic balance, as well as the role of the Achilles tendon in balance, in prediabetic patients. Materials and Methods: A total of 96 participants were divided into three groups: (1) the control group, consisting of participants without diabetes mellitus; (2) the prediabetes group; and (3) the diabetes mellitus group. Ultrasonographic measurements of Achilles tendon sizes (thickness, width and area) were performed. Dynamic balance was assessed using the Berg Balance Scale, and static balance (the Fall and Stability Indices) was assessed using a Tetrax device. The Self-Leeds Assessment of Neuropathic Symptoms and Signs was utilized to identify neuropathic pain. Results: In the prediabetes group, the median dynamic balance scores [54.0 (51.0-56.0)] were lower than those of the control group [55.0 (54.0-56.0)] but higher than those of the patients with diabetes mellitus [52.50 (49.0-54.25)]; however, this difference did not reach statistical significance. The ultrasonographic measurements of the Achilles tendon size were similar among the three groups. On the other hand, in the prediabetes group, a positive correlation was observed between the bilateral Achilles tendon anterior-posterior thickness and Fall Index score (p = 0.045), while a negative correlation was found between the left Achilles tendon anterior-posterior thickness and the Berg Balance Score (p = 0.045). Conclusions: In prediabetes, neither Achilles tendon size nor static or dynamic balance appears to be significantly affected. However, in prediabetic patients, increased Achilles tendon thickness appears to be associated with increased risk of falls and decreased balance.