A double CYP27A1 gene mutation in spinal cerebrotendinous xanthomatosis in a patient presenting with spastic gait: a case report.

BACKGROUND: Cerebrotendinous xanthomatosis (CTX, OMIM #213700) is a rare inherited metabolic disease caused by the mutation in the CYP27A1 gene. Spinal CTX is a rare clinical subgroup of CTX which lacks typical symptoms seen in classical CTX. Here we report a spinal CTX case revealed double mutation of CYP27A1 gene. CASE PRESENTATION: A 42-year-old Asian man visited our hospital with spastic gait started at 35. Physical examination showed bilateral masses on his Achilles tendons and were identified as xanthoma on ankle magnetic resonance imaging (MRI). Brain and spinal cord MRI revealed high signal lesions in bilateral cerebellar dentate nuclei and long tract lesions involving lateral corticospinal and gracile tracts. Gene analysis revealed double heterozygous mutation, c.223C > T (p. Gln75Ter) and c.1214G > A (p. Arg405Gln). CONCLUSIONS: We believe that novel mutation detected in our case might have a role in the pathomechanism in CTX. Moreover, spinal CTX should be considered in the patients only presenting with pyramidal symptoms, as CTX shows good prognosis in early treatment with chenodeoxycholic acid.

Reproducibility of pop sensation, Thompson sign in achillotomy, and final Pirani score to predict clubfoot relapse: Achillotomy clinical signs and Pirani predictive ability.

Ultrasound (US) can guide and confirm percutaneous release of the achilles tendon in the clubfoot. However, this technique may not always be available; therefore, surgeons' reported feelings of tendon release ("click" or "pop") and the Thompson sign could demonstrate that they are sensitive and reliable for confirming complete tendon release. The purpose of this study was to compare the reproducibility of clinical maneuvers that aim to detect the reported "click" or "pop" sensation by the surgeon and the Thompson sign after surgical release in percutaneous achilles tenotomy compare with US in patients with clubfoot. A cross-sectional reproducibility study of consecutive patients with idiopathic clubfoot was conducted. All the patients were scheduled to undergo tenotomy in the operating room using the standard percutaneous achilles tenotomy technique under sedation. The surgeon's reported surgical sensation ("click" or "pop") and Thompson signs were compared to the US assessment of the cut. The final Pirani score was used to predict recurrence risk and was correlated with the number of plaster casts and age. Forty-five feet were affected in 30 patients. Eighteen (60%) men. Age range: 1 to 60 months. The sensation of "click" or "pop" was recorded in 38 patients, and complete release was confirmed by US in 37 patients, for a sensitivity (Se) of 0.95 and specificity (Sp) of 0.63. Thompson signs were positive in 33 and 36 patients at 2 evaluations, with Se values of 0.87 and 0.92 and Sp values of 0.88 and 0.75, respectively. The Pirani final score, a predictor of recurrence risk, had an area under the curve of 0.80 (95% CI = 0.63-0.97; P = .005), Se = 0.78, and Sp = 0.56, with a cutoff point of 2.75. The feeling of achilles tendon release and Thompson sign had high sensitivity, prevalence, accuracy, and posttest probability. The confirmation of tendon release based on clinical signs could prevent the use of US.

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.

Achilles tendon assessment on quantitative MRI: Sources of variability and relationships to tendinopathy.

Quantitative MRI (qMRI) measures are useful in assessing musculoskeletal tissues, but application to tendon has been limited. The purposes of this study were to optimize, identify sources of variability, and establish reproducibility of qMRI to assess Achilles tendon. Additionally, preliminarily estimates of effect of tendon pathology on qMRI metrics and structure-function relationships between qMRI measures and ankle performance were examined. T1, T1ρ, T2, and T2* maps of the Achilles tendon were obtained using a 3T MRI scanner. In participants with asymptomatic tendons (n = 21), MRI procedures were repeated twice, and region of interest selection was performed by three raters. Variance decomposition and reproducibility statistics were completed. To estimate the effect of pathology, qMRI measures from individuals with asymptomatic tendons were compared to qMRI measures from a pilot group of individuals with Achilles tendinopathy (n = 7). Relationships between qMRI and ankle performance measures were assessed. Between-participant variation accounted for the majority of variability (46.7%-64.0%) in all qMRI measures except T2*. ICCs met or exceeded 0.7 for all qMRI measures when averaged across raters or scans. Relaxation times were significantly longer in tendinopathic tendons (mean (SD) T1: 977.8 (208.6) ms, T1ρ: 35.4 (7.1) ms, T2: 42.8 (7.9) ms, T2*: 14.1 (7.6) ms, n = 7) compared to asymptomatic control tendons (T1: 691.7 (32.4) ms, T1ρ: 24.0 (3.6) ms, T2: 24.4 (7.5) ms, T2*: 9.5 (3.4) ms, n = 21) (p < 0.011 for all comparisons). T1 related to functional performance measures in symptomatic and asymptomatic groups. Study findings suggest that qMRI is reliable to assess the Achilles tendon. qMRI quantitatively assesses the presence of tendon pathology and relates to functional performance outcomes, supporting the utility of incorporating qMRI in research and clinic.

Wearing an ultrasound probe during walking does not influence lower limb joint kinematics in adolescents with cerebral palsy and typically developing peers.

BACKGROUND: Enhancing traditional three-dimensional gait analysis with a portable ultrasound device at the lower-limb muscle-tendon level enables direct measurement of muscle and tendon lengths during walking. However, it is important to consider that the size of the ultrasound probe and its attachment on the lower limb may potentially influence gait pattern. RESEARCH QUESTION: What is the effect of wearing an ultrasound probe at the lower limb in adolescents with cerebral palsy and typically developing peers? METHODS: Eleven individuals with cerebral palsy and nine age-matched typically developing peers walking barefoot at their self-selected speed were analyzed. Data collection occurred under three conditions: the reference condition (GAIT), and two conditions involving placement of the ultrasound probe over the distal medial gastrocnemius-Achilles tendon junction (MTJ) and over the medial gastrocnemius mid-belly to capture fascicles (FAS). Data processing included calculating differences between conditions using root mean square error (RMSE) for joint kinematics and comparing them to the overall mean difference. Additionally, Spearman correlations were calculated to examine the relationship between kinematic RMSEs and walking speed. RESULTS: No significant differences in stance phase duration or walking speed were observed among the three conditions. Average RMSEs were below 5° for all parameters and condition comparisons in both groups. In both the TD and CP groups, RMSE values during the swing phase were higher than those during the stance phase for all joints. No significant correlations were found between height or body mass and swing phase RMSEs. In the CP group, there was a significant correlation between joint kinematics RMSEs and differences in walking speed at the hip, knee and ankle joints when comparing the MTJ condition with the GAIT condition. SIGNIFICANCE: This study confirms joint kinematics alterations are smaller than 5° due to wearing to the leg an ultrasound probe during walking.

Influence of preconditioning on morphological and mechanical properties of human Achilles tendon in vivo.

The present study aimed 1) to verify whether the effect of preconditioning was observed in the measured variables during the measurement of the human tendon in vivo (i.e., repeated contractions with breaks between trials) and 2) to determine the changes in tendon properties and their mechanisms due to submaximal repetitive contractions. Twelve healthy males participated in this study. To eliminate the effects of preconditioning, the participants rested on the measurement bed for 2 h before the start of both experiment-1 and experiment-2. In experiment-1, the measurements of elongation and hysteresis of the Achilles tendon for ramp and ballistic conditions were repeated ten times every 2 min. In experiment-2, participants performed submaximal repetitive contractions at 50 % of MVC and a frequency of 1 Hz for 10 min with a 30 s break every 2 min. Tendon mechanical properties were measured during contractions (starting 30 s and last 20 s of every 2 min), and the mean and coefficient variation (CV) of echogenicity were assessed during a 30-s rest every 2 min. In experiment-1, no significant differences in elongation and hysteresis of the tendon for ramp and ballistic contractions were found among the trials. In experiment 2, there were no significant differences in tendon elongation and hysteresis among all measurement times. Mean echogenicity increased significantly after 2 min, and CV of echogenicity decreased significantly after 4 min. These results suggest that preconditioning does not affect the elongation and hysteresis of the Achilles tendon in measuring tendon mechanical properties and submaximal repetitive contractions.

Salvage Reconstruction of a 12-cm Tendon Defect Following Chronic Achilles Rerupture-15-Year Follow-Up: A Case Report.

CASE: A 39-year-old man with a chronic Achilles rupture status post (1) failed primary repair and (2) secondary xenograft repair with graft rejection, resulting in a 12-cm Achilles tendon defect, which was reconstructed utilizing an Achilles bone block allograft and flexor hallucis longus (FHL) tendon transfer. At 15-year follow-up, the patient reported good functionality and satisfaction with the repair, with positive patient-reported outcome measures. Physical examination revealed excellent strength and range of motion. Magnetic resonance imaging confirmed the integrity and incorporation of the Achilles/FHL graft composite. CONCLUSION: This case study provides valuable insight into successful long-term management of complex chronic Achilles ruptures with large defects.

Normative ultrasound values for Achilles tendon thickness in the general population and patients with Achilles tendinopathy: A large international cross-sectional study.

The objective of the study was to obtain adjusted ultrasonographic reference values of the Achilles tendon thickness (maximum anterior-posterior distance) in adults without (previous) Achilles tendinopathy (AT) and to compare these reference values with AT patients. Six hundred participants were consecutively included, comprising 500 asymptomatic individuals and 100 patients with clinically diagnosed chronic AT. The maximum tendon thickness was assessed using Ultrasound Tissue Characterization. A multiple quantile regression model was developed, incorporating covariates (personal characteristics) that were found to have a significant impact on the maximum anterior-posterior distance of the Achilles tendon. A 95% reference interval (RI) was derived (50th, 2.5th-97.5th percentile). In asymptomatic participants median (95% RI) tendon thickness was 4.9 (3.8-6.9) mm for the midportion region and 3.7 (2.8-4.8) mm for the insertional region. Age, height, body mass index, and sex had a significant correlation with maximum tendon thickness. Median tendon thickness for the midportion region was calculated with the normative equation -2.1 + AGE × 0.021 + HEIGHT × 0.032+ BMI × 0.028 + SEX × 0.05. For the insertional region, the normative equation was -0.34 + AGE × 0.010+ HEIGHT × 0.018 + BMI × 0.022 + SEX × -0.05. In the equations, SEX is defined as 0 for males and 1 for females. Mean (95% CI) difference in tendon thickness compared to AT patients was 2.7 mm (2.3-3.2, p < 0.001) for the midportion and 1.4 mm (1.1-1.7, p < 0.001) for the insertional region. Compared to the asymptomatic population 73/100 (73%) AT patients exhibited increased tendon thickening, with values exceeding the 95% RI. This study presents novel reference values for the thickness of midportion and insertional region of the Achilles tendon, which were adjusted for personal characteristics. Our novel web-based openly accessible calculator for determining normative Achilles tendon thickness (www.achillestendontool.com) will be a useful resource in the diagnostic process. Trial registration number: This trial is registered in the Netherlands Trial Register (NL9010).

Diagnostic value of Achilles tendon shear wave elastography in patients with ankylosing spondylitis: A case-control study.

OBJECTIVES: Ankylosing spondylitis (AS) can cause peripheral arthritis, tendinitis, enthesitis, and axial skeletal involvement. This study aims to determine early tendon damage by shear wave elastography (SWE) for the Achilles tendon in AS patients. METHODS: 48 AS patients and 48 asymptomatic individuals were included in the study. Participants were systematically examined with B-mode, power Doppler, and SWE using a high-resolution linear 6-15 MHz probe. Bilateral Achilles tendon stiffness, thickness, and vascularity were evaluated. Measurements were taken from the middle third of the Achilles tendon in the sagittal plane. Difference between the two groups was evaluated with statistical methods. Receiver operating characteristic analysis was performed to test the diagnostic performance of Achilles tendon stiffness. Additionally, the Spearman correlation test examined the relationship between Achilles tendon stiffness and disease duration. RESULTS: The difference between the two groups regarding Achilles tendon stiffness was statistically significant (p < 0.05). It was observed that Achilles tendon stiffness decreased in the patient group compared with the control group. The diagnostic value of Achilles tendon stiffness measured by SWE was found to be high. A negative correlation was detected between disease duration and tendon stiffness (p < 0.05). CONCLUSION: In patients diagnosed with AS, deterioration in the Achilles tendon structure was observed, and a significant decrease in tendon stiffness compared with the healthy population. It has been determined that these changes in the Achilles tendon are related to the duration of the disease.

Medial arch instability/internal foot overload association with non-insertional Achilles tendinopathy and the 'Zone of Conflict Theory'.

BACKGROUND: Non insertional Achilles tendinopathy [AT] is a degenerative condition that is prevalent in runners. 30% have no preceding history and many runners do not develop AT. Overuse, pronation, and compromised blood supply are hypothesised as causal. The exact precipitant is still unknown. The link between medial arch instability and AT has not been made. The purpose of this study was to investigate the association between spring ligament (SL) laxity and first ray (FRI) instability, and the presence of (AT). METHODS: Ethical approval was obtained. Patients were identified from hospital databases for unilateral AT, allowing the opposite unaffected foot to be used as an internal control. SL laxity was measured using the lateral translation score and FRI was measured using a modified digital Klauemeter. Ultrasound was used to assess the tendoachilles [TA] in affected vs unaffected legs. RESULTS: 17 patients were recruited with a mean age of 55.6 and mean body mass index (BMI) of 33.3. The average symptom duration was 3.62 years. There were 12 left feet and 5 right feet. There was no statistical difference in dorsiflexion angles for the TA or the gastrocnemius. All Beighton scores < 5. Lateral translation scores, FRI scores and TA thickness was significantly greater in AT feet [p < 0.05]. More affected feet had Tibialis posterior tendon pain (TP) [p < 0.05]. CONCLUSIONS: Feet with AT exhibit higher lateral translation scores and greater FRI compared to healthy feet, and combined with previous literature evidence, suggests alteration of the subtalar axis alters force moments that may lead to an intrinsic overload of the TA, when the foot enters a "zone of conflict". Medial arch instability, in particular SL laxity and FRI, may contribute to the development of non-insertional AT and treatment of this with early arch support may prevent progressive degeneration.

Youth Athletes With Sever's Disease Exhibit Altered Achilles Tendon Ultrasound Characteristics: A Retrospective Case-Control Study.

OBJECTIVES: Calcaneal apophysitis (Sever's disease) is an overuse condition caused by repetitive traction stress to the calcaneal apophysis. Whether Achilles tendon morphology is altered in this young patient population remains unknown. Therefore, we aimed to identify differences in Achilles tendon morphology between youth athletes diagnosed with calcaneal apophysitis and healthy controls. METHODS: This retrospective chart review included 46 patients (n = 23 Sever's disease, 15F/8M, 12.4 ± 2.3 years old) and (n = 23 healthy controls, 13F/10M, 15.9 ± 1.5 years old) who sought care in a Children's Hospital Sports Medicine/Orthopedics Department between 2012 and 2022. We measured ultrasound-derived degree of tendon thickening, Achilles tendon thickness (cm), and cross-sectional area (CSA [cm2]). Separate multivariate analyses of covariance (MANCOVAs) were used to compare degree of thickening, mass-normalized Achilles tendon thickness, and CSA between participant groups, covarying for age. Cohen's d effect sizes were used to assess the magnitude of mean differences and standard error (MDSE) between groups. RESULTS: Young athletes with Sever's disease had a significantly greater degree of tendon thickening with a large effect compared with healthy controls (MDSE: 0.07 [0.01] mm P < .001, d = 1.39). Achilles tendon thickness and CSA did not statistically differ between groups; however, the magnitude of between-group differences for these measures (MDSE: 0.18 [0.05] cm, MDSE: 0.27 [0.07] cm2, respectively) were moderate. CONCLUSIONS: Our findings demonstrate previously unrecognized differences in Achilles tendon morphology between young athletes with clinically diagnosed Sever's disease and healthy controls. Our study supports incorporating diagnostic ultrasound as part of a comprehensive examination to ensure appropriate diagnosis and clinical management for adolescents with heel pain.

Haglund resection versus Haglund non-resection for calcific insertional Achilles tendinopathy with Haglund deformity: A retrospective study.

BACKGROUND: Calcific insertional Achilles tendinopathy(CIAT) with Haglund deformity is a type of recalcitrant tendinopathy. The necessity of concomitant removal of Haglund deformity during CIAT treatment is controversial. The present study aimed to evaluate the functional outcomes between Haglund resection and Haglund non-resection in the treatment of CIAT with Haglund deformity. METHODS: A retrospective study included 29 patients who were underwent Achilles tendon debridement, bursal excision, and subsequent tendon reattachment.for CIAT with Haglund deformity. All patients were divided into 2 groups according to Haglund resection (resection group, n = 16) and Haglund non-resection (non-resection group, n = 13) using the parallel line method on lateral calcaneal X ray after surgery. Patients were evaluated in terms of the American Orthopedic Foot and Ankle Society (AOFAS), Visual Analog Scale (VAS) and Victorian Institute of Sports Assessment-Achilles (VISA-A) scores and the mean time of activities of daily living (ADL). Anatomy changes included the Fowler-Philip angle, calcaneal pitch angle and Achilles tendon force arm were measured with radiography preoperatively and postoperatively. RESULTS: Both groups exhibited a significant increase in AOFAS, VAS and VISA-A scores after surgery. There were no significant differences between the resection group and the non-resection group for the AOFAS (92.38 ± 5.7 vs. 93.15 ± 12.17; P = 0.82), VAS (0.5 ± 0.52 vs. 0.61 ± 0.87; P = 0.66) and VISA-A questionnaire (82.56 ± 13.46 vs. 74.92 ± 16.4; P = 0.18) at the latest follow-up. The mean time of ADL in the non-resection group was significantly faster compared to that of the resection group (8.15 ± 2.51 weeks vs. 11.31 ± 4.06 weeks, P = 0.02). The Fowler-Philip angle of the resection group decreased from 55.55° ± 12.34° preoperatively to 44.52° ± 10.24° at the latest follow-up (P = 0.001). The Fowler-Philip angle of the non-resection group decreased from 54.38° ± 8.41° preoperatively to 46.52° ± 8.02° at the latest follow-up (P = 0.016). The calcaneal pitch angle of the resection group increased from 22.76° ± 5.37° preoperatively to 25.98° ± 6. 4° at the latest follow-up (P = 0.018). The Achilles tendon force arm of the resection group decreased from 178.50 mm ± 5.37 mm preoperatively to 173.90 mm ± 8.07 mm at the latest follow-up (P = 0.018). CONCLUSION: Resection or non-resection of the posterosuperior calcaneal tuberosity for CIAT with Haglund deformity would both provide satisfactory functional outcomes. Haglund non-resection may expedite patients' return to their daily activities, suggesting a Haglund deformity resection may be unnecessary in the surgical treatment for CIAT with Haglund deformity.

Power Doppler signal at the enthesis and bone erosions are the most discriminative OMERACT ultrasound lesions for SpA: results from the DEUS (Defining Enthesitis on Ultrasound in Spondyloarthritis) multicentre study.

OBJECTIVES: To assess, in spondyloarthritis (SpA), the discriminative value of the Outcome Measures in Rheumatology (OMERACT) ultrasound lesions of enthesitis and their associations with clinical features in this population. METHODS: In this multicentre study involving 20 rheumatology centres, clinical and ultrasound examinations of the lower limb large entheses were performed in 413 patients with SpA (axial SpA and psoriatic arthritis) and 282 disease controls (osteoarthritis and fibromyalgia). 'Active enthesitis' was defined as (1) power Doppler (PD) at the enthesis grade ≥1 plus entheseal thickening and/or hypoechoic areas, or (2) PD grade >1 (independent of the presence of entheseal thickening and/or hypoechoic areas). RESULTS: In the univariate analysis, all OMERACT lesions except enthesophytes/calcifications showed a significant association with SpA. PD (OR=8.77, 95% CI 4.40 to 19.20, p<0.001) and bone erosions (OR=4.75, 95% CI 2.43 to 10.10, p<0.001) retained this association in the multivariate analysis. Among the lower limb entheses, only the Achilles tendon was significantly associated with SpA (OR=1.93, 95% CI 1.30 to 2.88, p<0.001) in the multivariate analyses. Active enthesitis showed a significant association with SpA (OR=9.20, 95% CI 4.21 to 23.20, p<0.001), and unlike the individual OMERACT ultrasound lesions it was consistently associated with most clinical measures of SpA disease activity and severity in the regression analyses. CONCLUSIONS: This large multicentre study assessed the value of different ultrasound findings of enthesitis in SpA, identifying the most discriminative ultrasound lesions and entheseal sites for SpA. Ultrasound could differentiate between SpA-related enthesitis and other forms of entheseal pathology (ie, mechanical enthesitis), thus improving the assessment of entheseal involvement in SpA.

Achilles Tendon Stiffness in the Etiology of Sever Disease: A Shear Wave Elastography Study.

BACKGROUND: Sever disease is one of the most common causes of heel pain in growing children and adolescents. There is no consensus about etiology of Sever disease. METHODS: The study comprised 41 participants aged 8 to 13 years who visited the orthopedic outpatient clinic: 17 patients with Sever disease and 24 asymptomatic children. The middle third segment of the body of the Achilles tendon and the calcaneal insertion zone were separately assessed. Five measuring points for the quantitative value of each point were randomly selected. The color scale used in the Young's modulus shows the lowest values in blue and the highest values in red. The mean values were used for the statistical analysis. RESULTS: Less elasticity was detected at the insertional site for the control group (4.02 kPa versus 3.65 kPa), the situation was reversed in the body of the Achilles tendon and the elasticity of the study group was less than that of the control group (241.0 kPa versus 260.5 kPa). However, no statistically significant difference was found between the groups. CONCLUSIONS: In conclusion, no difference was found in Achilles tendon elasticity between patients with Sever disease and healthy individuals in both the tendon body and the calcaneal insertionof the tendon. Achilles tendon elasticity has not been found to play a role in the etiology of Sever disease.

Intrinsic ankle stiffness is associated with paradoxical calf muscle movement but not postural sway or age.

Due to Achilles tendon compliance, passive ankle stiffness is insufficient to stabilise the body when standing. This results in 'paradoxical' muscle movement, whereby calf muscles tend to shorten during forward body sway. Natural variation in stiffness may affect this movement. This may have consequences for postural control, with compliant ankles placing greater reliance upon active neural control rather than stretch reflexes. Previous research also suggests ageing reduces ankle stiffness, possibly contributing to reduced postural stability. Here we determine the relationship between ankle stiffness and calf muscle movement during standing, and whether this is associated with postural stability or age. Passive ankle stiffness was measured during quiet stance in 40 healthy volunteers ranging from 18 to 88 years of age. Medial gastrocnemius muscle length was also recorded using ultrasound. We found a significant inverse relationship between ankle stiffness and paradoxical muscle movement, that is, more compliant ankles were associated with greater muscle shortening during forward sway (r ≥ 0.33). This was seen during both quiet stance as well as voluntary sway. However, we found no significant effects of age upon stiffness, paradoxical motion or postural sway. Furthermore, neither paradoxical muscle motion nor ankle stiffness was associated with postural sway. These results show that natural variation in ankle stiffness alters the extent of paradoxical calf muscle movement during stance. However, the absence of a clear relationship to postural sway suggests that neural control mechanisms are more than capable of compensating for a lack of inherent joint stiffness.

Can the Achilles tendon regenerate completely following percutaneous tenotomy in older children with clubfoot?

PURPOSE: The aims of the study were to document the outcomes of percutaneous Achilles tenotomy (pAT) performed in older children with clubfoot, by assessing the clinical, functional and ultrasonographic evidence of Achilles tendon regeneration. METHODS: A retrospective case series of older children with clubfoot treated between August 2011 and July 2020 was studied. Clinical assessment of ankle range of motion and calf strength, functional assessment of triceps surae muscle endurance by single leg heel-rise test, and ultrasonographic assessment of Achilles tendon echotexture and dimensions to assess tendon regeneration were performed. RESULTS: Percutaneous Achilles tenotomy was performed on 31 children (48 clubfeet) at a mean age of 5.24 ± 2.14 years (1-10.2 years). At a mean follow-up of 4.86 ± 1.97 years, all children demonstrated normal calf strength with mean dorsiflexion range of 13.64° (0-25°) and mean plantarflexion range of 37.95° (10-40°). The heel-rise endurance test was completed by 27 children with mean 25.85 heel rises/minute (range 17-30) and mean height of heel rise of 6.29 cm (range 4-10 cm). Normal fibrillar tendinous echotexture with homogenous echogenicity was seen on ultrasonography in 41 feet (85.4%) with mean tendon width of 9.7 mm (3.3-16 mm) and thickness of 5.1 mm (1.8-15 mm), comparable with unaffected feet. CONCLUSIONS: Clinical, functional and ultrasonographic parameters unequivocally demonstrate complete regeneration of the Achilles tendon, when pAT is performed in older children with delayed-presenting idiopathic clubfoot treated using Ponseti principles.

Comparative analysis of patellar tendon, achilles tendon and plantar fascia structure in indoor and outdoor football players: a novel cross-sectional pilot study.

Different sport modalities were associate with tendon adaptation or even tendon disturbances, such as volleyball, soccer or basketball. Purpose: the aim of the present study was to determine de difference between indoor and outdoor football players on patellar tendon (PT), Achilles tendon (AT), plantar fascia (FP) and Hoffa's fat pad thickness assessed with ultrasound imaging (USI). A cross-sectional study was developed with a total sample of 30 soccer players divided in two groups: outdoor group (n = 15) and indoor group (n = 15). The thickness of PT, AT, PF and Hoffa's fat pad has been assessed with USI. Hoffa's fat pad reported significant differences for the left side between groups (P = 0.026). The rest of variables did not show any significant difference (P < 0.05). The ultrasonography assessment of the thickness of the PT, AT and PF did not show differences between outdoor and indoor football players. Hoffa's fat pad resulted showed a significant decrease for outdoor soccer players with respect futsal players. Thus, it can be considered that the load stimuli received in both soccer players were not enough to produce structural adaptations in PT, AT and PF tissues.

Differences in Achilles tendon mechanical properties between professional ballet dancers and collegiate athletes utilizing shear wave elastography.

PURPOSE: To report normative stiffness parameters obtained using shear wave elastography in dorsiflexion from the Achilles tendons in asymptomatic professional ballet dancers and compare them with college-level athletes. METHODS: An Institutional Review Board (IRB)-approved study consists of 28 professional ballet dancers and 64 asymptomatic collegiate athletes. The athletes were further subdivided into runner and non-runner disciplines. Shear wave elastography (SWE) measurements were made in maximum ankle dorsiflexion position. RESULTS AND DISCUSSION: Forty-eight (52%) males and 44 (48%) females were examined with an overall mean age of 22.2 (± 3.8 years). There were no significant SWE differences between dominant and non-dominant legs in both groups and comparing spin vs. non-spin leg of ballet dancers (p > 0.05). Ballet dancers had significantly higher short-axis velocity values than runners and non-runners (2.34 m/s increase and 2.79 m/s increase, respectively, p < 0.001). Long-axis velocity was significantly higher in ballet dancers compared to non-runners (by 0.80 m/s, p < 0.001), but was not different between ballet dancers and runners (p > 0.05). Short-axis modulus was significantly higher in dancers compared to runners and non-runners (by 135.2 kPa and 159.2 kPa, respectively, p < 0.001). Long-axis modulus (LAM) was not significantly different in ballet dancers when compared to runners. CONCLUSION: Asymptomatic professional ballet dancers exhibit greater short-axis tendon stiffness compared to athletes and greater long-axis tendon stiffness compared to non-runners but similar to runners. The functional benefit from elevated short-axis stiffness in dancers is not clear but may be related to greater axial loading and adaptations of the tendon matrix.

Factors associated with the presence of tendon xanthomas in familial hypercholesterolemia.

INTRODUCTION AND OBJECTIVES: Tendon xanthomas (TX) are lipid deposits highly specific to familial hypercholesterolemia (FH). However, there is significant variability in their presentation among FH patients, primarily due to largely unknown causes. Lipoprotein(a) is a well-established independent risk factor for atherosclerotic cardiovascular disease in the general population as well as in FH. Given the wide variability of lipoprotein(a) among FH individuals and the likelihood that TX may result from a proatherogenic and proinflammatory condition, the objective of this study was to analyze the size of TX in the Achilles tendons of FH participants and the variables associated with their presence, including lipoprotein(a) concentration. METHODS: A cross-sectional study was conducted on 377 participants with a molecular diagnosis of heterozygous FH. Achilles tendon maximum thickness (ATMT) was measured using ultrasonography with standardized equipment and procedures. Demographic variables and lipid profiles were collected. A multivariate linear regression model using a log-Gaussian approach was used to predict TX size. Classical cardiovascular risk factors and lipoprotein(a) were included as explanatory variables. RESULTS: The mean low-density lipoprotein cholesterol level was 277mg/dL without lipid-lowering treatment, and the median ATMT was 5.50mm. We demonstrated that age, sex, low-density lipoprotein cholesterol, and lipoprotein(a) were independently associated with ATMT. However, these 4 variables did not account for most the interindividual variability observed (R2=0.205). CONCLUSIONS: TX, a characteristic hallmark of FH, exhibit heterogeneity in their presentation. Interindividual variability can partially be explained by age, male sex, low-density lipoprotein cholesterol, and lipoprotein(a) but these factors account for only 20% of this heterogeneity.