Achilles Tendon Research Articles

Tensile Strength of the Achilles Tendon Allograft: A Comparative Study of Graft Preparation Technique

Background/Objectives: The Achilles tendon is a popular allograft option for anterior cruciate ligament (ACL) reconstruction. Structurally, the tendon is known to have a 90-degree rotational fiber track. Preparation techniques, with this consideration, may influence the strength of the graft. This study aims to assess the tensile strength of a novel Achilles tendon allograft harvest procedure following the rotational fiber track. Methods: Both Achilles tendons were harvested from formalin-embalmed cadavers [(n = 20), male n = 13, female n = 7, average age = 70]. Ten cadavers had the right Achilles as the control and the left Achilles as the fiber track sample; 10 cadavers had the opposing designation. Tensile strength was tested utilizing a Bose machine. An unpaired t-test was used to compare data across groups. Results: The average ultimate load for the control group was 874.17 N, with an average elastic stiffness of 76.01 N/mm. The ultimate load for the fiber track group was 807.84 N, with an average elastic stiffness of 64.75 N/mm. No statistically significant difference (p = 0.21) was determined between the average ultimate loads or elastic loads (p = 0.18) across groups. Conclusions: These data suggest that the rotational fiber track method of Achilles allograft has consistent tensile strength and elastic stiffness as compared to the common harvest procedure. The rotational fiber track method for ACL harvesting is a viable alternative option to the common harvest procedure for usage in an ACL reconstruction.

Mini-open versus percutaneous surgical repair for acute Achilles tendon rupture: a systematic review and meta-analysis.

To compare the clinical outcomes and complications of mini-open (MOT) and percutaneous techniques (PT) in the surgical repair of acute Achilles tendon rupture (AATR). We systematically searched PubMed, Scopus, Web of Science, Clinical Trials, and the Cochrane Library for studies comparing MOT with PT for AATR. We assessed functional outcomes, complication rates, and operation time. Statistical analyses were performed using RevMan Web. Odds ratios (ORs) and mean difference (MD) with 95% confidence intervals (CIs) were pooled with a fixed-effects model for dichotomous and continuous endpoints, respectively. Heterogeneity was evaluated with I2 statistics. Eight studies, comprising 484 patients, were included, of whom 226 (46%) underwent MOT. MOT was associated with a significantly lower re-rupture rate (1.48% vs. 6.11%; OR 0.28; 95% CI 0.09-0.86; p = 0.03; I2 = 6%) and sural nerve injury rate (0.57% vs. 5.64%; OR 0.24; 95% CI 0.07-0.81; p = 0.02; I2 = 0%). No significant differences were observed in venous thrombosis (OR 0.81; 95% CI 0.17-3.94; p = 0.33; I2 = 0%), wound infection (OR 0.56; 95% CI 0.12-2.62; p = 0.46; I2 = 0%), or operation time (MD 1.83min; 95% CI -1.13-4.79; p = 0.23; I2 = 88%). Functional outcomes showed higher American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scores in the MOT group (MD 1.52 points; 95% CI 0.62-2.42; p = 0.001; I2 = 3%), while (Achilles Tendon Total Rupture Score) ATRS, time to return to activities, and ankle plantar and dorsiflexion were comparable. MOT for AATR repair seems to reduce re-ruptures and sural nerve injuries while improving AOFAS scores, with no significant differences in other complications compared to PT. These findings suggest that the MOT may offer a safer and equally effective alternative to PT for AATR.

Lipoprotein(a) levels and cholesterol efflux capacity: inverse association and impact on atherosclerosis in familial hypercholesterolemia patients on lipid-lowering therapy

Abstract Backgrounds Familial hypercholesterolemia (FH) patients have higher serum lipoprotein(a) (Lp(a)) levels than non-FH patients, and high Lp(a) levels raise atherosclerotic cardiovascular disease (ASCVD) risk 1). We previously reported that decreased cholesterol efflux capacity (CEC) is a risk marker for ASCVD in patients with statin-treated FH 2). Others have reported that Lp(a) interferes with the enhancement of ABCA1-mediated cholesterol efflux by plasminogen and that ABCA1-mediated CEC is lower in patients with Lp(a) >50 mg/dL. However, the association of CEC, not necessarily ABCA1-mediated, with Lp(a) is not clear and has not been studied in patients with FH. It is also unclear whether high Lp(a) and low CEC in patients with FH are associated with the severity of atherosclerosis. Purpose We examined whether Lp(a) levels are negatively associated with ABCA1-independent CEC in patients with FH receiving lipid-lowering therapy. We also examined the impact of the combination of high Lp(a) and low CEC on the presence of corneal arcus, Achilles tendon thickness, carotid intima-media thickness (IMT), and pre-existing ASCVD. Methods This cross-sectional study included 371 patients clinically diagnosed with FH receiving lipid-lowering therapy. CEC was measured in apolipoprotein B-depleted plasma and 3H-cholesterol-labeled J774.1 cells without cAMP-stimulated ABCA1 overexpression. Lp(a) was measured by enzymatic methods (Sekisui Medical, Tokyo, Japan) using an automated analyser. Achilles tendon thickness was measured by X-ray and carotid IMT by ultrasound. Results Mean age was 55±16 years, and 191 (51%) were women. The median serum Lp(a) level was 18.7 mg/dL, higher than the previously reported median level (13 mg/dL) in a Japanese population. One hundred nineteen patients (32%) had serum Lp(a) levels of 30 mg/dL or higher, and they had significantly lower CEC (P=0.0015). This negative association persisted after adjusting for age, sex, BMI, smoking status, serum LDL-cholesterol, serum triglycerides, and eGFR in a multiple linear regression model (beta-coefficient: -0.047, 95% CI: -0.075 - -0.019, P=0.0011). In addition, patients with both Lp(a) > 30 mg/dL and CEC lower than the median had a higher percentage of corneal arcus, thicker Achilles tendons, greater carotid IMT, and a higher prevalence of pre-existing ASCVD compared to patients with either or neither. Conclusions We found an inverse relationship between Lp(a) levels and CEC in FH patients receiving lipid-lowering therapy. Our results suggest that Lp(a) may also inhibit ABCA1-independent CEC, including passive cholesterol diffusion from peripheral cells. Furthermore, the combination of high Lp(a) and low CEC may be a residual risk for patients with FH receiving lipid-lowering therapy. Future studies are needed to determine whether agents that decrease Lp(a) levels will increase CEC and thereby resolve part of the residual ASCVD risk in FH.

Discipline-specific adaptation patterns in respiratory and lower limb musculotendinous structures: cyclists vs. basketball players.

This study aimed at assessing how chronic exposure to specific exercise training (high-intensity intervals vs. endurance), comparing experienced basketball-players (BP, N.=16), cyclists (CY, N.=16), and non-specifically trained individuals (CN, N.=16), influences the structural and functional characteristics of both lower limb and respiratory musculotendinous structures. Vastus lateralis, gastrocnemius lateralis, and medialis, diaphragm muscles, as well as patellar tendon and Achilles tendon, were assessed using B-mode ultrasonography. Maximal voluntary isometric and passive torque measurements were conducted in the knee-extensors and plantar-flexors. Additionally, a subset of participants (N.=10 for each group) underwent a fatigue-inducing exercise-till-exhaustion protocol, and the strength of lower limb and respiratory muscles was evaluated immediately before and after the trial. Athletes had bigger and stronger musculotendinous structures and greater endurance to fatigue than CN (P<0.05). BP had bigger plantar-flexors and diaphragm, greater fascicles length, more explosive plantar-flexors and respiratory muscles and bigger tendons than CY (P<0.05). On the other hand, CY showed greater muscle pennation angle and greater endurance to fatigue for both, lower limb, and respiratory muscles (P<0.05). The present study emphasizes that chronic and specific exercise training leads to distinctive adaptations, not only in lower limb musculotendinous structures but also in other components such as respiratory muscles.

Conventional radiography and correlated factors of enthesopathies of the Achilles tendon and plantar fascia in patients with axial spondyloarthritis.

This study aimed to investigate the correlated risk factors and presence of radiological enthesopathies of the Achilles tendon and plantar fascia in patients with axial spondyloarthropathy (axSpA). 242 patients (121 female and 121 male) with axSpA were included in this study. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), the Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP), the Bath Ankylosing Spondylitis Radiology Index (BASRI), the Maastricht Ankylosing Spondylitis Enthesitis Score (MASES), and CRP were evaluated in all patients. The lateral foot X-rays of the patients were assessed for enthesopathies of the Achilles tendon and plantar fascia attachments. Calcaneal spur and Achilles enthesopathies were present in 57.4% of the patients. 39.3% of patients had enthesopathies in both regions. The male and female groups differed statistically in terms of weight, height, body mass index (BMI), positive family history, and duration since diagnosis (p<0.05). The presence of calcaneal spur and Achilles enthesopathies was found to be significantly correlated with age, weight, BMI, symptom duration, and the score of BASDAI, BASFI, ASDAS-CRP, BASRI, and MASES (p<0.05). The presence of enthesopathies appears to be associated with age, weight, BMI, symptom duration, and disease activity. Conventional radiography can be used as an auxiliary tool in the evaluation of entheseal abnormalities in patients with SpA, especially in patients with advanced age, long symptom duration, and high BMI.

Impact of changes of Achilles tendon thickening on cardiovascular events among patients with familial hypercholesterolemia

Abstract Backgrounds Achilles tendon thickening (ATT) can be regressed through LDL-lowering in patients with familial hypercholesterolemia (FH). The Japan Atherosclerosis Society (JAS) determined the threshold of ATT as ≥8.0 mm in male and ≥7.5 mm in female. Purpose We aimed to determine clinical impact of changes of ATT in development of major adverse cardiovascular events (MACE). Methods Patients with clinically diagnosed FH (N=1,273, male/female=614/659) with ATT data using X-ray were assessed. We divided the patients into 4 groups (group 1: patients without ATT from baseline to their follow-up, group 2: patients without ATT at baseline, but developed ATT at follow-up, group 3: patients with ATT at baseline, but regressed at follow-up, group 4: patients with ATT from baseline to their follow-up). Cox proportional hazards models were used to assess factors associated with MACE, including cardiovascular death and any coronary events. Results The median follow-up period was 10.9 years. During the follow-up period, 142 MACEs were observed, and median ATT was regressed from 7.8 to 7.6 mm. We found that there was more significant positive correlation between cholesterol-year score and ATT among patients with and without MACE (p &amp;lt;0.001; Spearman’s r=0.33, and p &amp;lt;0.001; Spearman’s r=0.35, respectively). Under these circumstances, changes of ATT were significantly associated with the occurrence of MACE (hazard ratio (HR): 2.73; 95% confidence interval (CI): 1.33–4.13; p&amp;lt;0.001, HR: 2.18; 95% CI: 1.08–3.28; p&amp;lt;0.001, HR: 6.34; 95% CI: 3.10–9.58; p&amp;lt;0.001, in group 2, group 3, and group 4, respectively when group 1 was considered as reference). Conclusion Assessments of ATT condition represent diagnostic values and risk stratification information among patients with FH.

Muscle‐Inspired Robust Anisotropic Cellulose Conductive Hydrogel for Multidirectional Strain Sensors and Implantable Bioelectronics

AbstractIntegrating superior mechanical performance, anisotropic conductivity, and biocompatibility into conductive hydrogels as all‐in‐one human‐machine interaction device remains challenging. Herein, by mimicking the anisotropic structures of human muscles, a robust anisotropic conductive hydrogel is developed by initially aligning polyvinyl alcohol with polypyrrole decorated cellulose nanofibrils to form an anisotropically oriented polymer networks, followed by post‐crosslinking with tannic acid (TA). Introducing TA into hydrogel network permanently secures its hierarchically anisotropic structure through multiple hydrogen bonds, thus endowing the hydrogel with exceptional mechanical properties (tensile strength of 11.41 MPa, toughness of 12.44 MJ m−3), anisotropic adhesive property, and direction‐dependent conductivity. With these attributes, a hydrogel strain sensor with excellent multidirectional sensitivity is developed, enabling stable monitoring of multi‐degrees of freedom joint movements in the human body and facilitating the control of a multiaxial virtual robot manipulator. Moreover, the in vitro/vivo tests demonstrate exceptional biocompatibility and anti‐biofouling properties of the as‐prepared hydrogel sensor, maintaining stable electronic response signals for over 14 days after successful implantation into the Achilles tendon of mice. Overall, this study presents a promising approach for designing conductive hydrogels with superior mechanical properties and anisotropic functionality for emerging applications in both in vitro and in vivo human‐machine interface materials.

Direct repair of the chronic ochronotic Achilles tendon rupture: a case report

BackgroundAlkaptonuria (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 presentationWe 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.ConclusionsWe 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.

Adaptive responses of skeletal muscle to calcaneal tendon partial injury in rats: insights into remodeling and plasticity.

Skeletal muscle is a highly adaptive tissue, capable of responding to different physiological and functional demands, even in situations that may cause instability. To evaluate how partial calcaneal tendon (CT) injuries affect the remodeling and plasticity of the gastrocnemius muscle over time. 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. 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. 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.

Effects of Maturation on Plantar Flexor Activity and Achilles Tendon Stiffness in Vertical Jumping: Sex Differences.

The aim of this study was to investigate the effect of maturation on vertical jumping performance, in adolescent boys and girls, concerning plantar flexor activity and Achilles tendon (AT) stiffness. Thirty-nine adolescents were tested in a counter-movement jump (CMJ) at three different time points: 18 and 9 months before peak height velocity (PHV) and at PHV. The EMG activity of the medialis gastrocnemius (MG) and tibialis anterior (TA) muscles was evaluated, in relation to jump height. Boys showed higher jumping ability and AT stiffness than girls. Additionally, boys revealed increased eccentric (ecc) and concentric (con) MG activity, along with decreased ecc and con TA activity, near PHV. On the other hand, girls showed increased ecc and con TA/MG co-contraction compared to boys, mainly near PHV. In conclusion, a different mechanism of vertical jumping performance is adopted between early adolescent boys and girls. Nevertheless, no notable alterations in jumping capability were detected over time, indicating that the maturation process does not influence stretch-shortening cycle (SSC) performance.

Foot Posture and Ankle Dorsiflexion as Risk Factors for Developing Achilles Tendinopathy and Plantar Fasciitis: A Case-Control Study.

Plantar fasciitis (PF) and Achilles tendinopathy (AT) are common injuries that primarily affect people engaged in sport or occupational weightbearing activities. Identifying modifiable risk factors is important for the treatment and prevention of these injuries. The purpose of this study was to evaluate whether foot posture or ankle dorsiflexion are risk factors for developing AT or PF, and if there were any differences between PF and AT patients. This was a case-control study of 108 patients with PF and 114 patients with AT, compared to the same number of referred patients in 2 control groups never having had these injuries, matched for sex, age, body mass index (BMI), sport, and occupational weightbearing activities. Included patients were 20-65 years with ultrasonographic-verified PF or midsubstance AT. Foot posture was assessed using Foot Posture Index (FPI) classifying the feet into 3 categories: FPI 0-5 normal foot, 6-12 hyperpronated, <0 hypopronated. Ankle dorsiflexion was measured with a goniometer in weightbearing with straight and bent knee. Abnormal foot posture was associated with an increased risk for sustaining both AT (odds ratio [OR] 3.4-4.1) and PF (OR 3.2-3.8). Hyperpronation being the major reason for this association with ORs 5.4-5.5 compared with hypopronation with ORs 2.6-2.9. However, decreased dorsiflexion was not a risk factor: instead, there was an increased ankle dorsiflexion in patients with AT or PF compared with their control groups. Comparison between PF and AT patients demonstrated that PF affected mostly women, and AT mostly men, PF patients were 2.4 years (CI 0.2-4.5) younger, and had 25% more occupational weightbearing than AT patients. However, no differences in BMI or weightbearing physical activity was demonstrated. Hypopronation and hyperpronation but not limited ankle dorsiflexion was associated with increased risk for AT or PF.

Comparison of short term recovery in patients with midportion Achilles tendinopathy with varying degrees of kinesiophobia treated with the Silbernagel protocol: A prospective single cohort analysis

ObjectiveTo assess short term recovery between individuals with Achilles tendinopathy with varying degrees of kinesiophobia when treated with the Silbernagel protocol. Secondarily to investigate short term change in degree of kinesiophobia. DesignProspective single cohort analysis. SettingUniversity/Clinical. Participants116 participants with midportion Achilles tendinopathy were grouped from their baseline Tampa Scale of Kinesiophobia (TSK) score: Low (≤33), Medium (34–41), and High (≥42). Main outcome measuresSymptom severity, Achilles tendon structure, and function were assessed at baseline and 8-weeks following initiation of the Silbernagel protocol. Differences in recovery between TSK groups were analyzed. ResultsNo group by time interactions were observed for symptoms, structure, or function. A significant interaction of group by time was observed for TSK score. The Medium (n = 66) and High (n = 28) TSK groups significantly decreased TSK score after 8 weeks by 2.4 and 4.4 points respectively while the Low TSK group (n = 22) did not change. ConclusionThere were no differences in short term recovery of symptoms, Achilles tendon structure, and function in individuals with midportion Achilles tendinopathy treated with the Silbernagel protocol regardless of baseline degree of kinesiophobia. Those with moderate and high levels of kinesiophobia at baseline decreased TSK score in the short term.

FGF-2 enriched nanofiber scaffold for advancing achilles tendon healing: a comparative experimental investigation

FGF-2 enriched nanofiber scaffold for advancing achilles tendon healing: a comparative experimental investigation

Epidemiology of Sports-Related Tendon Ruptures Presenting to Emergency Departments in the United States.

Participation in recreational and competitive sports can predispose people to musculoskeletal injuries. Chronic overuse with insufficient recovery, overloading, and direct contact can result in acute primary tendon ruptures. There is scarce literature regarding the epidemiology of sports-related acute primary tendon ruptures in the United States (US). To identify the incidence rate (IR) of sports-related acute primary tendon ruptures presenting to US emergency departments using the National Electronic Injury Surveillance System (NEISS) database and describe the trends in the IR from 2001 to 2020. Descriptive epidemiology study. The NEISS database was queried using injury case narratives; cases with a clear diagnosis of an acute primary tendon rupture were included in the final analysis. National estimates, estimated IRs (reported as per 1,000,000 person-years at risk), and temporal trends in the annual IR (reported as average annual percent change) of acute primary tendon ruptures were calculated using NEISS sample estimates and US Census Bureau population estimates. An estimated total of 141,382 patients (95% confidence interval [CI], 107,478-175,286) presented to US emergency departments with a sports-related tendon rupture over the study period (IR, 22.9 person-years at risk [95% CI, 17.4-28.3]). The mean age was 37.7 years (95% CI, 37.0-38.5). Of all cases of a tendon rupture identified from 2001 to 2020, 60.1% were secondary to exercise/sports-related injury mechanisms. An Achilles tendon rupture was the most common injury, representing 55.9% of cases. Basketball was the most common sports-related injury mechanism, accounting for 36.6% of cases. The overall injury rate in male patients was 7.7 times that of female patients (IR ratio, 7.7 [95% CI, 4.4-13.5]; P < .05). The annual incidence of all sports-related tendon ruptures in the US increased significantly from 2001 to 2020 (average annual percent change, 1.9 [95% CI, 1.0-2.8]; P < .01). Recreational/competitive sports participation accounted for a large proportion of acute primary tendon ruptures in the US during the study period.

Open Dorsal Closing-Wedge Calcaneal Osteotomy for Haglund Exostosis-Related Heel Pain.

Dorsal closing-wedge calcaneal osteotomy (DCWCO) is a treatment option for persistent Haglund exostosis-related heel pain after failed conservative management. In modifying the orientation of the calcaneal tendinous insertion site and reducing mechanical stress, the consequences of DCWCO-associated biomechanical changes on everyday foot function remain unknown. This retrospective cohort study analyzed routinely collected clinical data as well as data from our foot and ankle registry. One hundred twenty patients (66 males, 54 females, 17-77 years) who underwent DCWCO from January 2016 to December 2019 were included. Adverse events were collected from the patient files. Foot Function Index (FFI) scores were collected before (baseline) and at 6, 12, and 24 months postsurgery. Radiographic parameters including the Achilles tendon moment arm and X/Y ratio were evaluated from standard preoperative and 6-week postoperative radiographs. Correlations between FFI and biomechanical changes were calculated for men and women separately with the Pearson correlation coefficient and Bonferroni correction. One intra- and 18 postoperative adverse events were documented. Mean baseline FFI pain decreased from 47.9 ± 17.2 to 12.0 ± 17.5 points at 24 months with an average decrease of -21.8 ± 21.3 points occurring within the first 6 months postsurgery. A similar trend was also seen with the FFI disability score (49.6 ± 20.3 to 12.8 ± 17.6 points). The mean decrease in Achilles tendon moment arm was -8.1 ± 3.8 mm and mean X/Y ratio increased from 2.6 ± 0.3 to 3.8 ± 1.0. There were no significant correlations between the FFI score and radiographic changes. DCWCO effectively alleviates exostosis-related heel pain and associated disabilities. Improvements can still be expected up to 2 years after surgery. Radiographic changes of the foot and ankle are significant but do not correlate with patient-reported outcome measures.

Relationship Between Ultrasound and Physical Examination in the Assessment of Enthesitis in Patients With Spondyloarthritis: Results From the DEUS Multicenter Study.

The study objectives were (i) to explore the agreement between the Outcome Measures in Rheumatology (OMERACT) ultrasound lesions of enthesitis and physical examination in assessing enthesitis in patients with spondyloarthritis (SpA) and (ii) to investigate the prevalence and clinical relevance of subclinical enthesitis in this population. Twenty rheumatology centers participated in this cross-sectional study. Patients with SpA, including axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA), underwent both ultrasound scan and physical examination of large lower limb entheses. The OMERACT ultrasound lesions of enthesitis were considered, along with a recently proposed definition for "active enthesitis" by our group. Subclinical enthesitis was defined as the presence of "active enthesitis" in ≥1 enthesis in patients with SpA without clinical enthesitis (ie, number of positive entheses on physical examination and Leeds Enthesitis Index score = 0). A total of 4,130 entheses in 413 patients with SpA (224 with axSpA and 189 with PsA) were evaluated through ultrasound and physical examination. Agreement between ultrasound and physical examination ranged from moderate (ie, enthesophytes) to almost perfect (ie, power Doppler and "active enthesitis"). Patellar tendon entheses demonstrated the highest agreement, whereas Achilles tendon insertion showed the lowest. Among 158 (38.3%) of 413 patients with SpA with clinical enthesitis, 108 (68.4%) exhibited no "active enthesitis" on ultrasound. Conversely, of those 255 without clinical enthesitis, 39 (15.3%) showed subclinical enthesitis. Subclinical enthesitis was strongly associated with local structural damage. However, no differences were observed regarding the demographic and clinical profiles of patients with SpA with and without subclinical enthesitis. Our study underscores the need for a comprehensive tool integrating ultrasound and physical examination for assessing enthesitis in patients with SpA.

Voluntary exercise in mice triggers an anti-osteogenic and pro-tenogenic response in the ankle joint without affecting long bones

Biomechanical stimulation is proposed to occupy a central place in joint homeostasis, but the precise contribution of exercise remains elusive. We aimed to characterize in vivo the impact of mechanical stimulation on the cell-controlled regulation of ossification within the ankles of healthy mice undergoing mild physical activity. DBA/1 male mice were subjected to voluntary running exercise for two weeks, and compared to mice housed in standard conditions (n = 20 per group). Free access to activity wheels resulted in a running exercise of 5.5 ± 0.8 km/day at 14.5 ± 0.5 m/min. Serum levels of alkaline phosphatase, IL-6, IL-8/Kc, IL-17a, and TNF-α were measured. No change in systemic inflammation was detected. The bone architecture of the femur and the calcaneus was unchanged, as revealed by μCT and histology of the enthesis of the Achilles tendon. mRNAs were extracted from femurs, tibias, and ankle joints before RT-qPCR analysis. The expression of the mechanosensitive genes Sclerostin (Sost) and Periostin (Postn) was not impacted by the exercise in long bones. Oppositely, Sost and Postn levels were modulated by exercise in joints, and osteogenic markers (Col10a1, Runx2, Osx, and Dmp1) were downregulated in the exercise group. In addition, the tenogenic markers Scx, Mkx, and Tnmd were upregulated by exercise. Thus, voluntary exercise affected the phenotype of joint cells without impacting long bones. As gene expression of Bmp2, Bmp4, and Id1 was also reduced in these cells, an off-regulation of BMP signaling could be partly responsible for their mechanosensitive response. Running exercise seemed to preserve the tendon from its progressive ossification, as seen in numerous enthesopathies. This study paves the way to future experiments for investigating the effects of mechanical stimulation in various mouse models.

Investigating the Efficacy of Bioactive Sleeves with Embedded Nano-Semiconductors in Alleviating Tendinopathy: An In Vivo Pilot Study

INTRODUCTION Low-level laser therapy (LLLT) utilizes light transmitted at near-infrared wavelengths to induce biochemical changes that promote tissue healing. The Reparel® Sleeve is a Class I Device embedded with nano-semiconductor fibers that mimic LLLT to alleviate joint and tendon pain.The purpose of this study was to determine if bioactive sleeves with nano-semiconductor fibers can objectively affect tendinopathy. METHODS 12 New Zealand white rabbits received 0.2% collagenase injections into the right Achilles tendon. Rabbits were divided into three groups: group I received a sham sleeve (n=4); group II received a Reparel® sleeve I (n=4); and group III received Reparel® sleeve II (n=4). Calf circumference measurements and thermal radiation imaging of the right lower limb were collected on days 7, 14, 21, and 28 post-injection. Two rabbits from each group were sacrificed at 14 and 28 days, and right Achilles tendons were harvested. Histological analysis using Picrosirius red staining was performed to evaluate collagen fiber organization. Immunohistochemical staining was performed to evaluate M1/M2 macrophage activity. # RESULTS A statistically significant difference in calf circumference was found at the 28-day mark between group I versus groups II and III (p &lt; 0.05). Group I displayed an average circumference of 5.2 cm while groups II and III displayed circumferences of 4.9 and 4.6 cm, respectively. A downward trend in pixel density intensity was noted in the thermal radiation imaging for both sleeve groups. Histologic staining showed that group I displayed widespread disorganization and degradation of type I and III collagen fibers, while groups II and III displayed greater organization at the 28-day mark. Immunohistochemical staining revealed greater M1 macrophage activity in group I at the 14-day mark, and greater M2 macrophage activity in groups II and III at the 28-day mark. CONCLUSION The results of our study indicate that application of bioactive nano-semiconductor sleeves had a significant effect in alleviating Achilles tendinopathy, as seen by decreased swelling, temperature, and improved histology.

Biomechanical Changes to the Hindfoot After Zadek Osteotomy.

Insertional Achilles tendinopathy (IAT) is a common source of heel pain in active adults and athletes. The Zadek osteotomy (ZO) is a calcaneal dorsal closing wedge osteotomy that has demonstrated clinical success as a treatment for IAT, purported to favorably improve tendon mechanics, decrease impingement, and decrease pressure within the retrocalcaneal bursa. The present study aims to evaluate the biomechanical effects of ZO on Achilles strain, position of the Haglund prominence relative to the Achilles insertion, and retrocalcaneal pressure. The ZO was performed on 10 fresh-frozen foot and ankle mid tibia-fibula cadaveric specimens. An osteotomy was performed using a 1-cm dorsal closing wedge procedure secured with a 7.0 mm cannulated screw. Point pressure sensor catheters and differential variable reluctance transducers were used to measure the retrocalcaneal pressure and Achilles strain, respectively, pre- and postosteotomy. Paired t-tests were utilized to detect statistical differences (P < .05). After the ZO, the Haglund prominence was translated 9.9 mm anteriorly with respect to the insertion of the Achilles (P < .05) and the Achilles tendon insertion was translated 3.4 mm proximally (P < .05). The ratio of calcaneal length to greater tuberosity length, the X/Y ratio, increased from 2.56 to 3.52 with the osteotomy (P < .05). At maximum dorsiflexion, retrocalcaneal pressure decreased from 117 to 66 mm Hg (44%, P = .018). The Achilles strain changed from 0.00362 to 0.00436 in the anterior fibers (P = .484) and changed from 0.00467 to 0.00283 in the posterior fibers (P = .088). Biomechanical testing in a cadaveric model demonstrates that the ZO decreased retrocalcaneal pressure, shifted the Achilles tendon insertion proximally, increased the X/Y ratio of the calcaneus, and did not significantly change the strain of the Achilles tendon. Despite the clinical success demonstrated in recent literature, there are no biomechanical studies describing the effect of the ZO on the biomechanics of the hindfoot, and the mechanism of symptom relief of the ZO for IAT is not well understood. The present study measures two potential ZO effects relative to Haglund prominence by measuring retrocalcaneal pressure and displacement of the Achilles tendon with respect to the Haglund prominence, and measures one ZO effect relative to calcification of the tendon by measuring the Achilles tendon strain.

Minimum effective plyometric training volume in sedentary individuals: Impact on lower limb viscoelastic properties and functional performance in a randomised controlled trial

ABSTRACT Sedentary lifestyles reduce muscle mass, strength, power, and alter viscoelastic properties. Plyometric jump training (PJT) shows promise in countering these effects, but the optimal training volume for individuals with low athletic performance remains unclear. This study aimed to determine the minimal PJT volume required to improve muscle and tendon viscoelastic properties, strength, and power in sedentary individuals. A double-blind randomised controlled trial included 44 participants divided into three groups: Control Group (CG) (n = 16), Reduced Volume Training Group (RVTG) (n = 16), and Training Group (TG) (n = 12). The four-week PJT programme involved three weekly sessions with gradual volume increments; RVTG performed 50% less volume than TG. Baseline and follow-up assessments included the isokinetic standing up (SU) and sitting down (SD) phases at 15 cm/s and 5 cm/s, and myotonometer measurements. In the SU phase at 15 cm/s, significant differences were found (p = 0.01) with higher values in TG (10.0 ± 3.3 N/kg) compared to CG and RVTG. At 5 cm/s, differences in SD were observed (p = 0.002). For Achilles tendon properties in RVTG: stiffness (p = 0.04), decrement (p = 0.01), and relaxation (p = 0.02). A PJT volume of 2,414 jumps improved muscle strength, while 1,207 jumps altered tendon properties.