Achilles tendon morpho-mechanical parameters are related to triceps surae motor unit firing properties.

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. In addition, 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. NEW & NOTEWORTHY By employing HD-sEMG, conventional B-mode ultrasonography, and shear-wave elastography, we showed that the resting stiffness of the Achilles tendon is related to mean discharge rate of triceps surae motor units during low-force isometric plantarflexion contractions, providing relevant information about the complex interaction between rate coding and the muscle-tendon unit.

Estimation of the Achilles tendon twist in vivo by individual triceps surae muscle stimulation.

The Achilles tendon (AT) is composed of three distinct subtendons, each arising from one of the three heads of the triceps surae muscles: gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus (SOL). These subtendons exhibit a twisted structure, classified as low (Type I), medium (Type II), and high (Type III) twist, based on cadaveric studies. Nevertheless, the in vivo investigation of AT twist is notably scarce, resulting in a limited understanding of its functional significance. The aim of this study was to give insights into the complex 3D AT structure in vivo. A total of 30 healthy participants underwent individual stimulation of each of the triceps surae muscles at rest with the foot attached to the pedal of an isokinetic dynamometer. Ultrasound images were captured to concomitantly examine the displacement of the superficial, middle and deep AT layers. SOL stimulation resulted in the highest AT displacement followed by GM and GL stimulation. Independent of the muscle stimulated, non-uniformity within the AT was observed with the deep layer exhibiting more displacement compared to the middle and superficial layers, hence important inter-individual differences in AT displacement were noticeable. By comparing these individual displacement patterns during targeted stimulations with insights from cadaveric twist classifications on each subtendon area, our classification identified 19 subjects with a 'low' twist and 11 subjects with a 'high' twist. These findings enable us to move beyond cadaveric studies and relate the twisted microstructure of the AT in vivo to its dynamic behaviour.

Achilles tendon and enthesis assessment using ultrashort echo time magnetic resonance imaging (UTE-MRI) T1 and magnetization transfer (MT) modeling in psoriatic arthritis.

The purpose of this study is to investigate the use of ultrashort echo time (UTE) magnetic resonance imaging (MRI) techniques (T1 and magnetization transfer [MT] modeling) for imaging of the Achilles tendons and entheses in patients with psoriatic arthritis (PsA) compared with asymptomatic volunteers. The heels of twenty-six PsA patients (age 59 ± 15 years, 41% female) and twenty-seven asymptomatic volunteers (age 33 ± 11 years, 47% female) were scanned in the sagittal plane with UTE-T1 and UTE-MT modeling sequences on a 3-T clinical scanner. UTE-T1 and macromolecular proton fraction (MMF; the main outcome of MT modeling) were calculated in the tensile portions of the Achilles tendon and at the enthesis (close to the calcaneus bone). Mann-Whitney-U tests were used to examine statistically significant differences between the two cohorts. UTE-T1 in the entheses was significantly higher for the PsA group compared with the asymptomatic group (967 ± 145 vs. 872 ± 133 ms, p < 0.01). UTE-T1 in the tendons was also significantly higher for the PsA group (950 ± 145 vs. 850 ± 138 ms, p < 0.01). MMF in the entheses was significantly lower in the PsA group compared with the asymptomatic group (15% ± 3% vs. 18% ± 3%, p < 0.01). MMF in the tendons was also significantly lower in the PsA group compared with the asymptomatic group (17% ± 4% vs. 20% ± 5%, p < 0.01). Percentage differences in MMF between the asymptomatic and PsA groups (-16.6% and -15.0% for the enthesis and tendon, respectively) were higher than the T1 differences (10.8% and 11.7% for the enthesis and tendon, respectively). The results suggest higher T1 and lower MMF in the Achilles tendons and entheses in PsA patients compared with the asymptomatic group. This study highlights the potential of UTE-T1 and UTE-MT modeling for quantitative evaluation of entheses and tendons in PsA patients.

Effect of cilostazol on healing of achilles tendon ruptures: an experimental study on rats.

PURPOSE: This study aimed to evaluate whether cilostazol (phosphodiesterase III inhibitor) could enhance the healing of Achilles tendon ruptures in rats. MATERIALS AND METHODS: The Achilles tendons of 24 healthy male adult rats were incised and repaired. The rats were randomly allocated to cilostazol and control groups. The cilostazol group received daily intragastric administration of 50 mg/kg cilostazol for 28 days, while the control group did not receive any medication. The rats were sacrificed on the 30th day, and the Achilles tendon was evaluated for biomechanical properties, histopathological characteristics, and immunohistochemical analysis. RESULTS: All rats completed the experiment. The Movin sum score of the control group was significantly higher (p = 0.008) than that of the cilostazol group, with means of 11 ± 0.63 and 7.50 ± 1.15, respectively. Similarly, the mean Bonar score was significantly higher (p = 0.026) in the control group compared to the cilostazol group (8.33 ± 1.50 vs. 5.5 ± 0.54, respectively). Moreover, the Type I/Type III Collagen ratio was notably higher (p = 0.016) in the cilostazol group (52.2 ± 8.4) than in the control group (34.6 ± 10.2). The load to failure was substantially higher in the cilostazol group than in the control group (p = 0.034), suggesting that the tendons in the cilostazol group were stronger and exhibited greater resistance to failure. CONCLUSIONS: The results of this study suggest that cilostazol treatment significantly improves the biomechanical and histopathological parameters of the healing Achilles tendon in rats. Cilostazol might be a valuable supplementary therapy in treating Achilles tendon ruptures in humans. Additional clinical studies are, however, required to verify these outcomes.

Ossification of the posterior longitudinal ligament is linked to heterotopic ossification of the ankle/foot tendons.

INTRODUCTION: Systemic osteogenesis has been speculated to be involved in the pathogenesis of ossification of the posterior longitudinal ligament (OPLL). Our purpose was to compare the radiologic prevalence and severity of heterotopic ossification in foot tendons of Japanese patients with OPLL and to determine their association with systemic heterotopic ossification. MATERIALS AND METHODS: Clinical and radiographic data of 114 patients with OPLL were collected from 2020 to 2022. Control data were extracted from a medical database of 362 patients with ankle radiographs. Achilles and plantar tendon ossification were classified as grades 0-4, and the presence of osteophytes at five sites in the foot/ankle joint was assessed by radiography. Factors associated with the presence and severity of each ossification were evaluated by multivariable logistic regression and linear regression analysis. RESULTS: The prevalence of Achilles and plantar tendon ossification (grade ≥ 2) was 4.0-5.5 times higher in patients with OPLL (40-56%) than in the controls (10-11%). The presence of Achilles tendon ossification was associated with OPLL, age, and coexisting plantar tendon ossification, and was most strongly associated with OPLL (standardized regression coefficient, 0.79; 95% confidence interval, 1.34-2.38). The severity of Achilles and plantar tendon ossification was associated with the severity of ossification of the entire spinal ligament. CONCLUSIONS: The strong association of foot tendon ossification with OPLL suggests that patients with OPLL have a systemic osteogenesis background. These findings will provide a basis for exploring new treatment strategies for OPLL, including control of metabolic abnormalities.

Effects of a 12-week gait retraining program on the Achilles tendon adaptation of habitually shod runners.

PURPOSE: This study investigated the effects of a 12-week gait retraining program on the morphological and mechanical properties of the Achilles tendon (AT) during running on the basis of real-time dynamic ultrasound imaging. METHODS: A total of 30 male recreational runners who were used to wearing cushioned shoes with a rearfoot strike (RFS) pattern were recruited. They were randomized into a retraining group (RG, n = 15) and a control group (CG, n = 15). The RG group was asked to run in five-fingered minimalist shoes with a forefoot strike (FFS) pattern, and the CG group was asked to keep their strike pattern. Three training sessions were performed per week. All the participants in RG uploaded running tracks obtained through a mobile application (.jpg) after each session for training supervision. The ground reaction force, kinematics, and kinetics of the ankle joint at 10 km/h were collected using an instrumented split-belt treadmill and a motion capture system. The morphological (length and cross-sectional area) and mechanical characteristics (force, stress, strain, etc.) of AT in vivo were recorded and calculated with a synchronous ultrasonic imaging instrument before and after the intervention. Repeated two-way ANOVA was used to compare the aforementioned parameters. RESULTS: A total of 28 participants completed the training. The strike angle of RG after training was significantly smaller than that before training and significantly smaller than that of CG after training (F (1, 13) = 23.068, p < 0.001, partial η2 = 0.640). The length (F (1, 13) = 10.086, p = 0.007, partial η2 = 0.437) and CSA (F (1, 13) = 7.475, p = 0.017, partial η2 = 0.365) of AT in RG increased after training. A significant main effect for time was observed for the time-to-peak AT force (F (1, 13) = 5.225, p = 0.040, partial η2 = 0.287), average (F (1, 13) = 7.228, p = 0.019, partial η2 = 0.357), and peak AT loading rate (F (1, 13) = 11.687, p = 0.005, partial η2 = 0.473). CONCLUSION: Preliminary evidence indicated that a 12-week gait retraining program could exert a beneficial effect on AT. 57% (8/14) runners in RG shifted from RFS to FFS pattern. Although not all runners were categorized as FFS pattern after the intervention, their foot strike angle was reduced. Retraining primarily positively promoted AT morphological properties (i.e., CSA and length) to strengthen AT capability for mechanical loading.

Per-step and cumulative load at three common running injury locations: The effect of speed, surface gradient, and cadence.

Understanding how loading and damage on common running injury locations changes across speeds, surface gradients, and step frequencies may inform training programs and help guide progression/rehabilitation after injuries. However, research investigating tissue loading and damage in running is limited and fragmented across different studies, thereby impairing comparison between conditions and injury locations. This study examined per-step peak load and impulse, cumulative impulse, and cumulative weighted impulse (hereafter referred to as cumulative damage) on three common injury locations (patellofemoral joint, tibia, and Achilles tendon) across different speeds, surface gradients, and cadences. We also explored how cumulative damage in the different tissues changed across conditions relative to each other. Nineteen runners ran at five speeds (2.78, 3.0, 3.33, 4.0, 5.0 m s-1 ), and four gradients (-6, -3, +3, +6°), and three cadences (preferred, ±10 steps min-1 ) each at one speed. Patellofemoral, tibial, and Achilles tendon loading and damage were estimated from kinematic and kinetic data and compared between conditions using a linear mixed model. Increases in running speed increased patellofemoral cumulative damage, with nonsignificant increases for the tibia and Achilles tendon. Increases in cadence reduced damage to all tissues. Uphill running increased tibial and Achilles tendon, but decreased patellofemoral damage, while downhill running showed the reverse pattern. Per-step and cumulative loading, and cumulative loading and cumulative damage indices diverged across conditions. Moreover, changes in running speed, surface gradient, and step frequency lead to disproportional changes in relative cumulative damage on different structures. Methodological and practical implications for researchers and practitioners are discussed.

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

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

Reduced Intratendinous Sliding in Achilles Tendinopathy During Active Plantarflexion Regardless of Horizontal Foot Position.

PURPOSE: The Achilles tendon consists of three subtendons with the ability to slide relative to each other. As optimal intratendinous sliding is thought to reduce the overall stress in the tendon, alterations in sliding behavior could potentially play a role in the development of Achilles tendinopathy. The aims of this study were to investigate the difference in intratendinous sliding within the Achilles tendon during isometric contractions between asymptomatic controls and patients with Achilles tendinopathy and the effect of changing the horizontal foot position on intratendinous sliding in both groups. METHODS: Twenty-nine participants (13 Achilles tendinopathy and 16 controls) performed isometric plantarflexion contractions at 60% of their maximal voluntary contraction (MVC), in toes-neutral, and at 30% MVC in toes-neutral, toes-in, and toes-out positions during which ultrasound images were recorded. Intratendinous sliding was estimated as the superficial-to-middle and middle-to-deep relative displacement. RESULTS: Patients with Achilles tendinopathy present lower intratendinous sliding than asymptomatic controls. Regarding the horizontal foot position in both groups, the toes-out foot position resulted in increased sliding compared with both toes-neutral and toes-out foot position. CONCLUSION: We provided evidence that patients with Achilles tendinopathy show lower intratendinous sliding than asymptomatic controls. Since intratendinous sliding is a physiological feature of the Achilles tendon, the external foot position holds promise to increase sliding in patients with Achilles tendinopathy and promote healthy tendon behavior. Future research should investigate if implementing this external foot position in rehabilitation programs stimulates sliding within the Achilles tendon and improves clinical outcome.

Significant functional impairment and disability in individuals with psoriatic arthritis and Achilles tendon pain: a cross-sectional observational study.

The Achilles tendon (AT) insertion is the most common site of enthesitis in psoriatic arthritis (PsA). The structure and function of the AT in PsA, and the prevalence of mid-portion pathology, is unknown. To compare the structure and function of the AT in people with PsA with self-reported AT pain (PsA + AT), PsA without self-reported AT pain (PsA-AT) and healthy controls. A cross-sectional, observational study was conducted. The ATs were assessed by clinical and US examination (B-mode and Power Doppler), performance-based testing (bilateral heel raise test (HRT) and 10 m walk test), and patient-reported outcome measures (PROMs) (including the Victorian Institute of Sport Assessment-Achilles [VISA-A]). Between-group differences were described using descriptive statistics, Chi-squared testing, parametric (1-way ANOVA) and non-parametric (Mann-Whitney or Kruskal-Wallis) testing. 22 PsA (11 per group) and 11 healthy control participants who were comparable in terms of sex, age, and BMI (PsA-AT = longer PsA disease duration) were recruited. VISA-A scores were significantly worse in the PsA + AT group compared to the PsA-AT group and healthy controls (p < 0.001). Inflammatory US features were significantly more prevalent in the PsA + AT group (p < 0.001). Mid-portion AT pathology was observed in the PsA + AT group, irrespective of entheseal disease. Clinical examination alone missed 5/7 cases of 'active' US-confirmed AT enthesitis. AT functional deficits were significant in the PsA + AT group and both PsA groups had lower HRT repetition rates and walked slower compared to healthy controls. Less than 1/3 of the PsA + AT group had received podiatry or physiotherapy care. Significant differences in the structure and function of the AT in PsA were noted. Despite management in line with current guidance, AT pain appears to persist and can result in severe functional impairment.

Effects of acupuncture and acupressure of the acupoint compared to the tendon on the blood circulation of human tendon in vivo.

PURPOSE: The purpose of this study was to compare the effects of acupuncture and acupressure of acupoints on tendon blood circulation with those of both types of stimulation of tendon itself. METHODS: Before, during (except for acupressure), and after acupuncture and acupressure of the tendon and acupoint, blood circulation of the Achilles tendon was measured using red laser lights. RESULTS: The blood volume of the treated and non-treated tendons increased after acupuncture of the tendon (effect of time p = 0.030), whereas that tended to increase after acupuncture of the acupoint (effect of time p = 0.063). In addition, no significant difference in the increases in blood volume was found among the four conditions, i.e., after acupuncture stimulation of the tendon and acupoint for the treated and non-treated tendons (p = 0.492). The blood volume of the treated tendon significantly increased after acupressure of the tendon (effect of time p < 0.001), but not of the acupoint (effect of time p = 0.260), whereas that of the non-treated tendon did not change after acupressure of both the tendon and acupoint. CONCLUSION: These results suggested that acupuncture of the tendon and acupoint acted centrally to enhance blood circulation of both the treated and non-treated tendons during the recovery period, whereas acupressure of the tendon locally increased blood circulation of the treated tendon only, but not the non-treated tendon and both the treated and non-treated tendons after acupressure of acupoint.

Structure and function of Achilles and patellar tendons following moderate slow resistance training in young and old men.

The aim of this study was to investigate the effect of aging and resistance training with a moderate load on the size and mechanical properties of the patellar (PT) and Achilles tendon (AT) and their associated aponeuroses; medial gastrocnemius (MG) and vastus lateralis (VL). Young (Y55; 24.8 ± 3.8 yrs, n = 11) and old men (O55; 70.0 ± 4.6 yrs, n = 13) were assigned to undergo a training program (12 weeks; 3 times/week) of moderate slow resistance training [55% of one repetition maximum (RM)] of the triceps surae and quadriceps muscles. Tendon dimensions were assessed using 1.5 T magnetic resonance imaging before and after 12 weeks. AT and PT cross sectional area (CSA) were determined every 10% of tendon length. Mechanical properties of the free AT, MG aponeurosis, PT, and VL aponeurosis were assessed using ultrasonography (deformation) and tendon force measurements. CSA of the AT but not PT was greater in O55 compared with Y55. At baseline, mechanical properties were generally lower in O55 than Y55 for AT, MG aponeurosis and VL aponeurosis (Young's modulus) but not for PT. CSA of the AT and PT increased equally in both groups following training. Further, for a given force, stiffness and Young's modulus also increased equally for VL aponeurosis and AT, for boths groups. The present study highlights that except for the PT, older men have lower tendon (AT, MG aponeurosis, and VL aponeurosis) mechanical properties than young men and 12-weeks of moderate slow resistance training appears sufficient to improve tendon size and mechanical adaptations in both young and older men. New and Noteworthy: These novel findings suggest that short-term moderate slow resistance training induces equal improvements in tendon size and mechanics regardless of age.

Advanced glycation end products impair the repair of injured tendon: a study in rats.

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. MATERIALS AND 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. CONCLUSION: 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.

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

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

The learning curve for minimally invasive Achilles repair using the "lumbar puncture needle and oval forceps" technique.

INTRODUCTION: An acute Achilles tendon rupture represents a common tendon injury, and its operative methods have been developed over the years. This study aimed to quantify the learning curve for the minimally invasive acute Achilles tendon rupture repair. METHODS: From May 2020 to June 2022, sixty-seven patient cases who received minimally invasive tendon repair were reviewed. Baseline data and operative details were collected. The cumulative summation (CUSUM) control chart was used for the learning curve analyses. Achilles tendon rupture score (ATRS), American Orthopedic Foot and Ankle Society (AOFAS) ankle/hindfoot score, and visual analog scale (VAS) at 3/6/9/12 months were calculated to assess the clinical outcomes. RESULTS: Thirty-six cases underwent at least a year of follow up and were enrolled in this study. The gender ratio and average age were 80.5% and 32.5 years. The linear equation fitted well (R2 = 0.95), and CUSUM for operative time peaked in the 12th case, which was divided into the learning phase (n = 12) and master phase (n = 24). No significant difference was detected between the two groups in clinical variables, except for the operative time (71.1 ± 13.2 min vs 45.8 ± 7.2 min, p = 0.004). Moreover, we detected one case with a suture reaction and treated it properly. CONCLUSION: Minimally invasive Achilles repair provides an opportunity for early rehabilitation. Notably, the learning curve showed that the "lumbar puncture needle and oval forceps" technique was accessible to surgeons.

Dynamic ultrasound assessment for insertional achilles tendinopathy: the COcco-RIcci (CORI) sign.

OBJECTIVE: To describe a novel, dynamic ultrasound assessment of the Achilles tendon at the calcaneal insertion taking advantage of the effusion within the deep retrocalcaneal bursa as a natural contrast agent. MATERIALS AND METHODS: Positioning the ultrasound transducer in a longitudinal plane over the Achilles tendon at the calcaneal insertion, manual compression of the deep retrocalcaneal bursa can be performed using the other hand. Dynamically shifting the anechoic effusion from the proximal to the distal compartment of the bursa, the undersurface of the Achilles tendon is lifted from the underlying cortical bone of the superior facet of the calcaneal tuberosity. RESULTS: Pushing the anechoic effusion from the bursal cavity toward the undersurface of the Achilles tendon, an eventual focal injury of its deep fibers can be visualized dynamically during the maneuver as a "black crescent" within the tendon-i.e., the COcco-RIcci (CORI) sign. Otherwise, the gliding of the posteroinferior wedge of the Kager's fat pad inside the tendon-bone interface can be observed in normal conditions. CONCLUSION: The CORI sign is a novel sonographic sign to further enhance the diagnostic accuracy of dynamic ultrasound imaging in patients with insertional Achilles tendinopathy especially to detect focal injury involving the deep fibers of the tendon.

Low socioeconomic status is associated with worse treatment outcomes in patients with Achilles tendinopathy.

OBJECTIVE: To assess whether there is a difference in symptom severity at baseline and 24 weeks follow-up between conservatively managed patients with Achilles tendinopathy (AT) with low socioeconomic status (SES) compared with those with high SES. METHODS: In this prospective cohort study, 200 patients with AT were included and treated according to current guidelines. We linked a neighbourhood SES indicator based on income, employment and education level and divided the patient population into quintiles, with Q1 being the highest SES and Q5 the lowest. Symptom severity at baseline and follow-up was assessed using the Victorian Institute of Sports Assessment-Achilles (VISA-A) score. Treatment adherence was not measured. We used a general linear model and the mean VISA-A scores at baseline and at 6, 12 and 24 weeks follow-up were compared between Q1 (n=45) and Q5 (n=39), while adjusting for age, sex, body mass index (BMI), Ankle Activity Score, symptom duration and baseline VISA-A score. RESULTS: Patients had a median age of 51 years and median BMI of 25.4, 40% were female. 74%, 70% and 58% of the participants completed the VISA-A at 6, 12 and 24 weeks, respectively. VISA-A scores at baseline were similar for Q1 and Q5 (43.9 and 41.8, p=0.591). At 24 weeks, there was a mean (95% CI) difference of 11.2 (1.0 to 21.3, p=0.032) points in favour of Q1 on the VISA-A score. CONCLUSION: AT patients with low SES may have worse outcomes when treated using the current guidelines. The difference in VISA-A score at 24 weeks is larger than the minimal clinically important difference and might be clinically relevant, but comes with uncertainty due to the large dispersion in the data. Clinicians need to consider the impact of social inequality when developing and implementing treatment plans.

ICON 2023: International Scientific Tendinopathy Symposium Consensus - the core outcome set for Achilles tendinopathy (COS-AT) using a systematic review and a Delphi study of professional participants and patients.

To develop a core outcome set for Achilles tendinopathy (COS-AT) for use in clinical trials we performed a five-step process including (1) a systematic review of available outcome measurement instruments, (2) an online survey on truth and feasibility of the available measurement instruments, (3) an assessment of the methodological quality of the selected outcome measurement instruments, (4) an online survey on the outcome measurement instruments as COS and (5) a consensus in-person meeting. Both surveys were completed by healthcare professionals and patients. The Outcome Measures in Rheumatology guidelines with a 70% threshold for consensus were followed. We identified 233 different outcome measurement instruments from 307 included studies; 177 were mapped within the International Scientific Tendinopathy Symposium Consensus core domains. 31 participants (12 patients) completed the first online survey (response rate 94%). 22/177 (12%) outcome measurement instruments were deemed truthful and feasible and their measurement properties were evaluated. 29 participants (12 patients) completed the second online survey (response rate 88%) and three outcome measurement instruments were endorsed: the Victorian Institute of Sports Assessment-Achilles questionnaire, the single-leg heel rise test and evaluating pain after activity using a Visual Analogue Scale (VAS, 0-10). 12 participants (1 patient) attended the final consensus meeting, and 1 additional outcome measurement instrument was endorsed: evaluating pain during activity/loading using a VAS (0-10). It is recommended that the identified COS-AT will be used in future clinical trials evaluating the effectiveness of an intervention. This will facilitate comparing outcomes of intervention strategies, data pooling and further progression of knowledge about AT. As COS-AT is implemented, further evidence on measurement properties of included measures and new outcome measurement instruments should lead to its review and refinement.

Topical glyceryl trinitrate (GTN) and eccentric exercises in the treatment of mid-portion achilles tendinopathy (the NEAT trial): a randomised double-blind placebo-controlled trial.

OBJECTIVES: To investigate if daily treatment with glyceryl trinitrate (GTN) ointment, over 24 weeks combined with a 12-week eccentric exercise programme is more effective for chronic mid-portion Achilles tendinopathy than placebo ointment and eccentric exercise. METHODS: This was a single-site randomised double-blind placebo-controlled trial at an acute hospital, Dublin, Ireland. Patients with chronic mid-portion Achilles tendinopathy were randomised to either 24 weeks of daily GTN ointment or placebo ointment. Both groups received an identical 12-week eccentric exercise programme. The primary outcome measure was the Victorian Institute of Sport Assessment-Achilles (VISA-A) questionnaire at 24 weeks, which measures pain, function and activity. Secondary outcomes included pain severity, self-reported physical function, calf muscle function, pressure pain thresholds and ultrasound changes. Statistical analyses were performed according to intention-to-treat principles. RESULTS: 76 patients (30 women; 46 men, mean age±SD, 45.6±8.2 years) were recruited for the trial. Significant improvements in VISA-A scores occurred in both groups at 6-week, 12-week and 24-week follow-up. The increase was not significantly different between groups, adjusted mean between-group difference from baseline to week 6, -1.33 (95% CI -6.96 to 4.31); week 12, -1.25 (95% CI -8.0 to 5.49) and week 24, -3.8 (95% CI -10.6 to 3.0); negative values favour GTN. There was no significant between-group difference in any of the secondary outcome measures at 6, 12 and 24 weeks. CONCLUSIONS: Adding daily GTN ointment over 24 weeks to a 12-week eccentric exercise programme did not improve pain, function and activity level in patients with chronic mid-portion Achilles tendinopathy when compared with placebo ointment.

Tendon structure, clinical tests, and pain during-loading in young female competitive gymnasts.

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.