Biomechanical stress in the context of competitive sports training triggers enthesitis

Ultrasound Changes in the Enthesis and Peri-enthesis Area of the Patellar and Achilles Tendons in Response to Physical Exercise: Comparison Between Healthy Subjects and Patients with Spondyloarthritis in Clinical Remission

RATIONALE AND OBJECTIVES

The goal of achieving clinical remission in patients with spondyloarthritis does not necessarily include the resolution of entheseal inflammation from a histological perspective. However, enthesis not clinically inflamed, under mechanical stress, may behave differently from healthy subjects considering the physiopathology of SpA. Our goal was to determine whether ultrasound changes in entheses differ between SpA patients in clinical remission and healthy subjects.

METHODS

SpA patients in clinical remission and matched healthy controls were recruited. At baseline, the following variables were measured on the dominant side by ultrasound: thickness of the distal patellar enthesis (hDP), the deep infrapatellar bursa (hDIB), the Achilles enthesis (hA), the preachilleal bursa (hPAB), effusion in the preachileal bursa (hePAB), and the presence of power Doppler signal in both enthesis. All measurements except hDP and hA were collected again after exercise (post-stress ultrasound).

RESULTS

30 patients and 30 controls were enrolled. In all subjects, hDIB, hPAB, and the preachileal bursa occupancy index increased significantly after the exercise. The increase was significantly greater in patients for all variables. At baseline, in patients, hyperemia was detected in one patellar tendon (3.3%) and in two Achilles tendons (6.7%). After exercise, the number of tendons with hyperemia increased to 11/30 (36.7%) and 12/30 (40%), respectively. Among controls, there was no detectable basal hyperemia, but after exercise, it was detected in 1/30 patellar tendons (3.3%) and 2/30 Achilles tendons (6.7%).

CONCLUSION

Exercise triggers a greater effusive and hyperemic synovial response in patients in remission than in healthy controls. These findings suggest that the definition of remission should also include an assessment of the synovial response to mechanical stress.

HIGHLIGHTS

Enthesopathies - Mechanical, inflammatory or both?

Entheses have the challenging task of transferring biomechanical forces between tendon and bone, two tissues that differ greatly in composition and mechanical properties. Consequently, entheses are adapted to withstand these forces through continuous repair mechanisms. Locally specialized cells (mechanosensitive tenocytes) are crucial in the repair, physiologically triggering biochemical processes to maintain hemostasis. When repetitive forces cause "material fatigue," or trauma exceeds the entheses' repair capacity, structural changes occur, and patients become symptomatic. Clinical assessment of enthesopathies mainly depends on subjective reports by the patient and lacks specificity, especially in patients with central sensitization syndromes. Ultrasonography has been increasingly used to improve the diagnosis of enthesopathies. In this article, the literature on how biomechanical forces lead to entheseal inflammation, including factors contributing to differentiation into a "clinical enthesitis" state and the value of ultrasound to diagnose enthesopathies will be reviewed, as well as providing clues to overcome the pitfalls of imaging.

Tolerability of low to moderate biomechanical stress during leisure sport activity in patients with psoriasis and psoriatic arthritis

OBJECTIVES

To assess the impact of low to moderate biomechanical stress on entheses in patients with psoriasis and psoriatic arthritis (PsA).

METHODS

We conducted a prospective interventional study on a cohort of psoriasis and PsA patients who underwent a 60 min badminton training session. Pain assessment by Visual Analogue Scale (VAS), physical examination of 29 entheses (SPARCC, LEI, MASES) and bilateral ultrasound at the lateral humeral epicondyle, inferior patellar pole and Achilles tendon were performed before and after training. Ultrasound changes were assessed using the OMERACT scoring system. A follow-up assessment of pain and adverse events was performed at 1 week.

RESULTS

Sixteen patients were included (n=7 PsA; n=9 psoriasis) and 196 entheseal ultrasound scans were acquired. At baseline, median VAS pain (IQR) was 0.5 cm (0-2.3) and the total number of tender entheses was 12/464. Mean (min; max) Disease Activity Index for Psoriatic Arthritis was 6.1 (0.8; 19) and 5/7 PsA patients had an Minimal Disease Activity status. After training, no significant change in VAS pain (0.0 cm (0.0-2.0)) nor in tender entheses (13/464) emerged. Four patients (n=2 PsA, n=2 psoriasis) developed a grade-1 power Doppler-signal at six entheses, which, however, remained non-tender. At 1 week, median VAS pain remained stable (0.0 cm (0.0-3.0); p>0.05) and only one participant with active PsA at baseline reported increased arthralgias in three joints.

CONCLUSIONS

Low to moderate physical strain, as in the context of leisure sport activity, seems well tolerated in psoriatic patients without increases in tenderness, pain and ultrasound-proven inflammation. Evidence-based recommendations for physical activity in PsA are direly needed and larger controlled studies should be conducted to define safe exercise thresholds.

Association between biological immunotherapy for psoriasis and time to incident inflammatory arthritis: limitations and opportunities

Psoriatic arthritis (PsA) is a chronic inflammatory immune-mediated disease that affects approximately 30% of psoriasis patients. In most cases, skin disease clearly precedes the musculoskeletal disease. Some studies suggest that targeted treatment may intercept the disease course and prevent psoriasis patients from developing PsA. A recent population-based retrospective analysis in 15 501 psoriasis patients evaluated the association between different biological treatment strategies and time to incident inflammatory arthritis based on data in a US electronic health records database. A cumulative incidence of 2.6 PsA cases per 100 person-years was determined. The multivariable regression analysis revealed a significantly lower risk of developing inflammatory arthritis in patients who had been prescribed interleukin (IL)-12/23 or IL-23 inhibitors compared with tumour necrosis factor (TNF) inhibitor-treated patients, whereas there was no significant difference in risk for patients prescribed inhibitors of IL-17 versus TNF. Although the analysis was based on a large set of clinical data and the findings were rigorously evaluated, there are some limitations in interpretation due to the study design. Prospective clinical trials are missing, and retrospective data analyses from clinical trials or population-based studies show conflicting results. Overall, the recent data on prevention of PsA in patients with psoriasis support the high need to characterise biomarkers of increased risk and perform prospective clinical trials to give a clear guidance on possibilities for disease interception in psoriatic disease.

Pathways driving tendinopathy and enthesitis: siblings or distant cousins in musculoskeletal medicine?

Tendinopathy and enthesitis share clinical, anatomical, and molecular parallels. However, their relationship is complex, presenting challenges in diagnosis and treatment. The biomechanics underlying these pathologies, together with relative immune and stromal contributions to pathology, are characterised by crucial comparative elements. However, methodologies used to study enthesitis and tendinopathy have been divergent, which could account for discrepancies in how these conditions are perceived and treated. In this Review, we summarise key clinical parallels between these two common presentations in musculoskeletal medicine and address factors that currently preclude development of more effective therapeutics. Furthermore, we describe molecular similarities and disparities that govern pathological mechanisms in tendinopathy and enthesitis, thus informing translational studies and treatment strategies.

Prevalence of joint, entheseal, tendon, and bursal findings in young, healthy individuals by musculoskeletal ultrasound

OBJECTIVE

The purpose of this study was to determine the prevalence of joint, enthesis, bursa, and tendon ultrasound findings in large and medium joints of young, healthy individuals.

METHOD

Ultrasound assessment of large and medium joints, bursae, tendons, and entheses was performed in healthy individuals below the age of 30 years. Participants also underwent bioelectrical impedance analysis and conducted supervised weight training to determine maximum strength. The prevalence of ultrasound findings was calculated and a binary logistic regression model was applied to evaluate factors associated with the present findings.

RESULTS

Fifty-one healthy individuals (52.9% female) with a mean age of 23.7 years were included in this study. Joint effusion in at least one joint was observed in 72.6% of the individuals (n = 37) and entheseal pathology in at least one enthesis was detected in 27.5% (n = 14). A binary logistic regression model indicated a significant association between reported hours of sports activity per week and the prevalence of effusion in the knee (p = 0.017). In addition, associations were observed between entheseal pathology in at least one entheseal site and body mass index (BMI) (p = 0.015) as well as fat mass index (p = 0.026).

CONCLUSION

Joint effusion in large and medium joints, as well as entheseal hyperperfusion, bursal effusion, and tendon sheath effusion, are found in healthy individuals. Hours of sports activity per week, BMI and fat mass index showed significant associations with the findings in joints and entheses.

Changes in ultrasound imaging of joints, entheses, bursae and tendons 24 and 48 h after adjusted weight training

Background:

Joint effusion and enthesitis are common ultrasound findings in rheumatic diseases such as rheumatoid arthritis or spondyloarthritis. However, changes of joints and entheses were not only observed in patients but also in physically active individuals and athletes.

Objectives:

The purpose of this study was to evaluate joint, entheseal, bursal and tendon musculoskeletal ultrasound (MSUS) findings in large and medium joints of young healthy individuals after completing a standardised weight training.

Design:

This is a prospective cohort study.

Methods:

MSUS examinations of large- and medium-sized joints, and related entheseal sites, bursae and tendons were performed on young healthy individuals (ages 18–30 years). Before, 24 and 48 h after completing 1 h of standardised weight exercise, the subjects were evaluated by MSUS. The development of the MSUS findings and associated effects were examined using generalised linear mixed effects models.

Results:

In total, 51 healthy individuals (52.9% female) with a mean age of 23.7 (±2.5) years were enrolled. The results showed an increase in the number of individuals with at least one joint effusion from 37 (72.5%) before the weight training to 48 (94.1%) after 48 h. Entheses with pathologies were observed in 14 participants (27.5%) at baseline, increasing to 29 participants (56.9%) 48 h after the weight training. Biceps tendon sheath effusion was detected in 9 individuals (17.6%) prior to training, rising to 22 individuals (43.1%) after 48 h. A significant increase in the number of joints with effusion and abnormal entheses within 48 h after the weight training was indicated by the generalised linear mixed effects models.

Conclusion:

Within 48 h after the weight training session, a significant increase in the prevalence of joint effusion in large and medium joints and the prevalence of abnormal entheses was observed. As a result, when performing and interpreting an MSUS examination, the patient’s physical activities should be taken into account.

Advanced genomics and clinical phenotypes in psoriatic arthritis

Psoriatic Arthritis (PsA) is a complex polygenic inflammatory disease showing a variable musculoskeletal involvement in patients with skin psoriasis. PsA coexist in 25-40 % of patients with the dermatological manifestations, but PsA may also predate the appearance of psoriasis. Nonetheless, the immunopathogenesis of psoriasis and PsA manifest significant similarities, with a major role of the individual susceptibility in both cases. Genome wide association studies (GWAS) identified several genes/loci associated with the risk to develop PsA, both dependent and independent of psoriasis. The major challenge is thus represented by the need to translate the identification of functional polymorphisms and other genetics findings into biological mechanisms along with the identification of novel putative drug targets. A functional genomics approach aims to increase GWAS power and recent evidence supports the use of a multilayer process, including eQTL, methylome, chromatin conformation analysis and genome editing to discover novel genes that can be affected by disease-associated variants, such as PsA. The available data have considered PsA as a unique homogeneous clinical entity while the clinical experience supports a wide variability of skin and joint manifestations coexisting in diverse patients with different mechanisms underlying the musculoskeletal and dermatological domains. A better discrimination of the patient features is encouraged by the limited data on functional genomics. We provide herein a review of the latest findings on PsA functional genomics highlighting the exciting developments in the field and how these might lead to a better understanding of gene regulation underpinning disease mechanisms and ultimately refine clinical phenotyping.

Reliability of a New Semi-automatic Image Analysis Method for Evaluating the Doppler Signal and Intratendinous Vascular Resistance in Patellar Tendinopathy

The aim of this study was to determine the intra- and inter-rater reliability of a new semi-automatic image analysis method for quantification of the shape of the Doppler signal and the intratendinous vascular resistance in patellar tendinopathy. Thirty athletes (27.4 y, standard deviation = 8.57 y) with patellar intratendinous vascularity were included in a cross-sectional study (42 tendons analyzed). The intratendinous blood flow was assessed with power Doppler and ImageJ (Version 1.50b, National Institutes of Health, Bethesda, MD, USA) quantification software over a manually selected region of interest. Two blinded observers performed the analysis of the Doppler signal (vascular resistance) and shape descriptors (number of signals, pixel intensity, area, perimeter, major diameter, minor diameter, circularity and solidity). The intraclass correlation coefficient (ICC) was calculated, and the Bland-Altman mean of differences (MoD) and 95% limits of agreement (LoA) were determined. Also, small real differences (SRDs) and the standard error of measurement (SEM) were calculated. Intra-rater reliability was at a maximum for area (ICC = 0.999, 95% confidence interval [CI] = 0.998-0.999) and at a minimum for solidity (ICC = 0.782, 95% CI: 0.682-0.853). The MoD and 95% LoA were very low, and the relative SRD and SEM were below 5.3% and 2%, respectively. The inter-rater reliability was the maximum for area (ICC = 0.993, 95% CI = 0.989-0.996) and the minimum for circularity (ICC = 0.73; 95% CI=0.611-0.817). The MoD and 95% LoA were low, with the SRD and SEM below 6% and 2.2%. The proposed quantitative method for studying the intratendinous Doppler signal in the patellar tendon is reliable and reproducible.