Foot functions in ankylosing spondylitis

Does ankylosing spondylitis exert a bidirectional influence on hypertension? A two-sample Mendelian randomization study

Objective

Previous observational studies reported that ankylosing spondylitis is closely related to hypertension. However, it is still controversial whether the association between ankylosing spondylitis and hypertension is causal. The effects of ankylosing spondylitis on diastolic and systolic blood pressure deserve further investigation. The objective of our study is to explore whether ankylosing spondylitis is causally associated with blood pressure.

Methods

A bidirectional two-sample Mendelian randomization (MR) analysis was performed by employing five Mendelian randomization analysis methods. MR Egger regression, weighted median, inverse variance weighted, and weight mode methods were performed in the two-sample Mendelian randomization analysis. We performed Mendelian randomization to investigate the association between ankylosing spondylitis (finn-b-M13_ANKYLOSPON) and hypertension (ukb-b-14057), diastolic blood pressure (ebi-a-GCST90000062) and systolic blood pressure (ebi-a-GCST90000059). We also performed reverse Mendelian randomization between exposures and outcomes. Another new validation cohort (ukb-b-18194) was also performed. The heterogeneity, horizontal pleiotropy, and possible outliers were examined in the MR analysis results.

Results

The inverse variance weighted results showed that ankylosing spondylitis has no genetic causal relationship with hypertension (p = 0.441, OR = 1.001, 95% CI: 0.999-1.002). The inverse variance weighted results showed that ankylosing spondylitis has no genetic causal relationship with systolic blood pressure (p = 0.301, OR = 1.006, 95% CI: 0.995-1.018). The inverse variance weighted results showed that ankylosing spondylitis has no genetic causal relationship with diastolic blood pressure (p = 0.778, OR = 1.002, 95% CI: 0.988-1.016). The reverse Mendelian randomization between exposures and outcomes is negative. Another new validation cohort also confirmed the results. No heterogeneity was observed by the MR-pleiotropy residual sum and outlier test. The "leave-one-out" analysis indicated that the results of MR analysis were not affected by a single nucleotide polymorphism.

Conclusion

This study represents the first two-sample Mendelian randomization analysis aimed at investigating the causal genetic relationship between ankylosing spondylitis and blood pressure. Our Mendelian randomization analysis results revealed a lack of causal association between ankylosing spondylitis and hypertension, diastolic blood pressure, as well as systolic blood pressure.

Optomechanical Analysis of Gait in Patients with Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease associated with alterations in posture and gait. The aim of this study was to assess the gait of AS patients using pedobarography and a markerless motion capture system. This is the first study of this population to combine these two methods. Twelve AS patients and twelve healthy controls were enrolled in this study. An instrumented gait analysis of both groups was performed using pedobarography and Microsoft Kinect v2. The AS group was significantly older than the controls (p < 0.05). The AS group showed a significantly lower relative pressure distribution in the front-right quadrant (p = 0.01) and a significantly higher relative pressure distribution in the rear-right quadrant (p = 0.05) on the static pedobarography. The AS group also had a higher peak force in the midfoot on the dynamic pedobarography (p < 0.05). The AS group had a significantly shorter stride length (p = 0.01). No significant differences between the groups were found in their hip flexion/extension and adduction/abduction, knee flexion, or ankle dorsiflexion/plantarflexion angles. This study shows significant alterations in the pedobarographic and spatiotemporal, but not in the kinematic, gait parameters of AS patients. These alterations represent a feature of AS and not antalgic adjustments. Rehabilitation programs for AS patients could be tailored according to the results of an instrumented gait analysis and should include balance and gait exercises.

Association between gait profile and spinal alignment in patients with adolescent idiopathic scoliosis

This study aimed to investigate the association between gait profile and spinal alignment in adolescent idiopathic scoliosis (AIS). The study group consisted of 80 AIS and 80 healthy controls. All participants underwent radiographic imaging and measured gait analysis. The gait profile included gait speed, step length, stance phase, cadence, single leg support, double legs support, gait asymmetry (GA), and phase coordination index (PCI). The spinal alignment parameters included pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), and coronal balance (CB). The mean age of the AIS group was 15.1 years, while the control group was 14.6 years. Significant differences were observed between the AIS patients and controls in gait speed, step length, stance phase, cadence, single leg support, double legs support, GA, PT, TK, SVA, and CB. However, no significant differences were found in PCI, SS, PI, and LL (p > 0.05). Additionally, correlation analysis revealed a close relationship between gait profile and spinal alignment parameters. Step length was significantly related to PT, SS, and LL, while GA was correlated with TK in AIS patients. Multiple regression analysis for predictors of step length found that PT and SS accurately predicted step length. First, the AIS group showed significant differences in gait kinematics and spinal alignment compared to the control group. Second, statistically significant correlations were found between gait profile and spinal alignment parameters. Specifically, PT and SS accurately predicted step length, and TK was correlated with GA in AIS patients.

Morphological changes in flatfoot: a 3D analysis using weight-bearing CT scans

BACKGROUND

Flatfoot is a condition resulting from complex three-dimensional (3D) morphological changes. Most Previous studies have been constrained by using two-dimensional radiographs and non-weight-bearing conditions. The deformity in flatfoot is associated with the 3D morphology of the bone. These morphological changes affect the force line conduction of the hindfoot/midfoot/forefoot, leading to further morphological alterations. Given that a two-dimensional plane axis overlooks the 3D structural information, it is essential to measure the 3D model of the entire foot in conjunction with the definition under the standing position. This study aims to analyze the morphological changes in flatfoot using 3D measurements from weight-bearing CT (WBCT).

METHOD

In this retrospective comparative our CT database was searched between 4-2021 and 3-2022. Following inclusion criteria were used: Patients were required to exhibit clinical symptoms suggestive of flatfoot, including painful swelling of the medial plantar area or abnormal gait, corroborated by clinical examination and confirmatory radiological findings on CT or MRI. Healthy participants were required to be free of any foot diseases or conditions affecting lower limb movement. After applying the exclusion criteria (Flatfoot with other foot diseases), CT scans (mean age = 20.9375, SD = 16.1) confirmed eligible for further analysis. The distance, angle in sagittal/transverse/coronal planes, and volume of the two groups were compared on reconstructed 3D models using the t-test. Logistic regression was used to identify flatfoot risk factors, which were then analyzed using receiver operating characteristic curves and nomogram.

RESULT

The flatfoot group exhibited significantly lower values for calcaneofibular distance (p = 0.001), sagittal and transverse calcaneal inclination angle (p < 0.001), medial column height (p < 0.001), sagittal talonavicular coverage angle (p < 0.001), and sagittal (p < 0.001) and transverse (p = 0.015) Hibb angle. In contrast, the sagittal lateral talocalcaneal angle (p = 0.013), sagittal (p < 0.001) and transverse (p = 0.004) talocalcaneal angle, transverse talonavicular coverage angle (p < 0.001), coronal Hibb angle (p < 0.001), and sagittal (p < 0.001) and transverse (p = 0.001) Meary's angle were significantly higher in the flatfoot group. The sagittal Hibb angle (B =  - 0.379, OR = 0.684) and medial column height (B =  - 0.990, OR = 0.372) were identified as significant risk factors for acquiring a flatfoot.

CONCLUSION

The findings validate the 3D spatial position alterations in flatfoot. These include the abduction of the forefoot and prolapse of the first metatarsal proximal, the arch collapsed, subluxation of the talonavicular joint in the midfoot, adduction and valgus of the calcaneus, adduction and plantar ward movement of the talus in the hindfoot, along with the first metatarsal's abduction and dorsiflexion in the forefoot.

Preliminary Studies on Changes in Static Plantar Pressure and Stabilometry in Patients with Ankylosing Spondylitis Undergoing an Exercise Program

Background/Objectives: Studies have reported that patients suffering from ankylosing spondylitis (AS) have decreased postural stability in comparison to healthy subjects. Our study aims to compare static plantar pressure and stabilometry parameters in AS patients who performed an 8-week exercise program (spine motion and flexibility exercises; stretching of hamstring, erector spine, and shoulder muscles; control abdominal and diaphragm breathing exercises and chest expansion exercises), in three different testing conditions (eyes open, eyes closed, and head retroflexed). Methods: Plantar pressure (the loading of the first and fifth metatarsal heads (MT1, MT5) and calcaneus) and stabilometry (CoP path length, 90% confidence ellipse area, and maximum CoP speed) were recorded in 28 AS patients (age 56.64 ± 10.3 years; body mass index 29.4 ± 4.9 kg/m2) at the beginning of rehabilitation and after 8 weeks. At first evaluation, there were significant differences (p < 0.05) for the foot loading sites (MT1, MT5, and calcaneus), both for the right and left feet, when comparing eyes open with the other two testing situations. Results: After rehabilitation, significant differences were recorded between eyes-open and head-retroflexed conditions for MT1 (p = 0.03 for right; p = 0.004 for left) and calcaneus (p = 0.014 for right; p = 0.011 for left). A significantly higher CoP path length was registered in both initial and final assessments when tested with eyes closed. The maximum CoP speed had increased values at both evaluations when tested with head retroflexed. Conclusions: The CoP path length decreased after the physical exercise program, with a better postural stability after rehabilitation.

Impact of ankylosing spondylitis on foot health and quality of life: an observational case-control study

Background

Ankylosing spondylitis (AS) is a chronic, inflammatory, and autoimmune disease. This condition primarily affects the axial skeleton and presents direct foot involvement, such as Achilles enthesitis or plantar fascia involvement.

Objective

This study aimed to investigate the impact of foot health on the quality of life of individuals with AS compared to a control group without AS.

Materials and methods

A sample of 112 subjects was recruited, with a mean age of 46.80 ± 10.49 years, divided into two groups: 56 individuals with AS (cases) and 56 individuals without AS (controls). Demographic data were collected, and the scores obtained in the Foot Health Status Questionnaire domains were recorded.

Results

Of the participants, 27.79% (N = 30) were men and 73.21% (N = 82) were women. The mean age in the group was 46.80 ± 10.49. Significant differences (p < 0.05) were found in the domains of foot function, foot pain, footwear, overall foot health, general health-related physical activity, and social capacity between the AS group and the control group.

Conclusion

Individuals with AS exhibited a decreased quality of life, as indicated by their Foot Health Status Questionnaire scores.

Relationships between Clinical Status and Gait Parameters in Ankylosing Spondylitis

Background

This study aimed to identify the relationship between gait parameters and health-related quality of life (HRQOL) in patients with ankylosing spondylitis (AS).

Methods

The study group comprised 134 patients with AS and 124 patients were enrolled as controls. All study participants underwent instrumented gait analysis and completed clinical questionnaires. The kinematic parameters of gait were walking speed, step length, cadence, stance phase, single support, double support, phase coordination index (PCI), and gait asymmetry (GA). For each patient, a visual analog scale (VAS; 0-10) score was used to assess back pain, 36-item short form survey (SF-36) questionnaire was administered to evaluate the HRQOL, and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was calculated. Using kinematic parameters and questionnaires, statistical analyses were done to investigate significant differences between the groups. Relationship of gait kinematic data and questionnaires of clinical outcome was also evaluated.

Results

Among the 134 patients with AS, 34 were women and 100 were men. In the control group, 26 were women and 98 were men. The patients with AS and control group patients had significant differences in terms of walking speed, step length, single support, PCI, and GA. However, such differences were not observed in cadence, stance phase, and double support (p > 0.05). In correlation analyses, gait kinematic parameters and clinical outcomes were significantly related with each other. In multiple regression analysis performed to identify predictive factors for clinical outcome, walking speed was found to predict VAS, and walking speed and step length were found to predict the BASDAI and SF-36 scores.

Conclusions

Patients with and without AS had significant differences in the gait parameters. Correlation analysis showed significant correlation between the gait kinematic data and clinical outcomes. In particular, walking speed and step length successfully predicted clinical outcomes in patients with AS.

Foot Deformity in Patients With Ankylosing Spondylitis: Is It Associated With Functionality and Disease Activity?

Foot involvement affects mobility and functionality in patients with ankylosing spondylitis but it remains unknown if foot deformities in ankylosing spondylitis patients affect functionality, disease activity, and quality of life. The aim of this study was to evaluate in detail the presence of a relationship between radiologically detected foot deformities in ankylosing spondylitis patients and both clinical and electrophysiological findings. The cross-sectional study included 110 patients with ankylosing spondylitis who were diagnosed according to the Assessment in Spondyloarthritis International Society criteria and were followed in our hospital. Demographic and clinical data of all patients were recorded. Bilateral lateral foot x-rays and electrophysiology examinations were evaluated in all subjects. The arch in the dominant foot of the patients was classified in 3 groups as pes cavus, pes planus, or normal. The clinical outcomes, physical examination and electrophysiological findings were compared between the groups, and correlations were examined of the foot deformities with these parameters. Foot deformities were determined at a high rate (74.5%). These deformities affected foot pain, disability and quality of life. Pes cavus deformity was found to be associated with hip pain and enthesopathy. In the electrophysiological studies, the presence of pes planus was found to be associated with the findings of the tibial and sural nerve conduction studies, and the presence of pes cavus with the findings of the peroneal nerve conduction study. In conclusion, foot deformities may have an effect on the quality of life and functionality in ankylosing spondylitis patients.

Static foot posture and its relation to clinical variables in ankylosing spondylitis

AIM

Postural abnormalities of the foot are common in rheumatic diseases. Static foot posture is a poorly studied clinical parameter in ankylosing spondylitis (AS). The aim of the study was to evaluate static foot posture in patients with AS and to determine the potential impact of clinical variables on foot posture.

METHOD

Fifty patients with AS and 40 age- and sex-matched healthy controls were enrolled in the study. Disease activity was measured using the Ankylosing Spondylitis Disease Activity Score. Axial mobility was evaluated with the Bath Ankylosing Spondylitis Metrology Index three-point answer scale. Functional status was assessed by the Bath Ankylosing Spondylitis Functional Index and Health Assessment Questionnaire-Disability Index. Enthesitis and foot posture were evaluated by the Maastricht Ankylosing Spondylitis Enthesitis Score (MASES) and Foot Posture Index-6, respectively.

RESULTS

Patients with AS revealed significantly higher scores of foot posture index when compared with controls (P = 0.005). Abnormal foot posture (pronated and supinated) was more common in the patient group (P < 0.01). According to the multinomial logistic regression analysis, a higher MASES score was associated with supinated foot posture in AS patients (odds ratio 1.47, 95% confidence interval 1.03-2.09, P = 0.035). In addition, supinated foot posture was associated with enthesitis of the Achilles tendon (P = 0.002).

CONCLUSION

Enthesitis is related to deteriorated static foot posture in patients with AS. Enthesitis of the Achilles tendon is closely associated with the supinated foot posture.

Clinical guidance for podiatrists in the management of foot problems in rheumatic disorders: evaluation of an educational programme for podiatrists using a mixed methods design

Background

Foot and ankle problems are common in rheumatic disorders and often lead to pain and limitations in functioning, affecting quality of life. There appears to be large variability in the management of foot problems in rheumatic disorders across podiatrists. To increase uniformity and quality of podiatry care for rheumatoid arthritis (RA), osteoarthritis (OA), spondyloarthritis (SpA), and gout a clinical protocol has been developed.

Research objectives

[1] to evaluate an educational programme to train podiatrists in the use of the protocol and [2] to explore barriers and facilitators for the use of the protocol in daily practice.

Method

This study used a mixed method design and included 32 podiatrists in the Netherlands. An educational programme was developed and provided to train the podiatrists in the use of the protocol. They thereafter received a digital questionnaire to evaluate the educational programme. Subsequently, podiatrists used the protocol for three months in their practice. Facilitators and barriers that they experienced in the use of the protocol were determined by a questionnaire. Semi-structured interviews were held to get more in-depth understanding.

Results

The mean satisfaction with the educational programme was 7.6 (SD 1.11), on a 11 point scale. Practical knowledge on joint palpation, programme variation and the use of practice cases were valued most. The protocol appeared to provide support in the diagnosis, treatment and evaluation of foot problems in rheumatic disorders and the treatment recommendations were clear and understandable. The main barrier for use of the protocol was time. The protocol has not yet been implemented in the electronic patient file, which makes it more time consuming. Other experienced barriers were the reimbursement for the treatment and financial compensation.

Conclusions

The educational programme concerning the clinical protocol for foot problems in rheumatic disorders appears to be helpful for podiatrists. Podiatrists perceived the protocol as being supportive during patient management. Barriers for use of the protocol were identified and should be addressed prior to large scale implementation. Whether the protocol is also beneficial for patients, needs to be determined in future research.

Foot-Worn Inertial Sensors Are Reliable to Assess Spatiotemporal Gait Parameters in Axial Spondyloarthritis under Single and Dual Task Walking in Axial Spondyloarthritis

The aim of this study was (1) to evaluate the relative and absolute reliability of gait parameters during walking in single- and dual-task conditions in patients with axial spondyloarthritis (axSpA), (2) to evaluate the absolute and relative reliability of dual task effects (DTE) parameters, and (3) to determine the number of trials required to ensure reliable gait assessment, in patients with axSpA. Twenty patients with axSpa performed a 10-m walk test in single- and dual-task conditions, three times for each condition. Spatiotemporal, symmetry, and DTE gait parameters were calculated from foot-worn inertial sensors. The relative reliability (intraclass correlation coefficients-ICC) and absolute reliability (standard error of measurement-SEM and minimum detectable change-MDC) were calculated for these parameters in each condition. Spatiotemporal gait parameters showed good to excellent reliability in both conditions (0.59 < ICC < 0.90). The reliability of symmetry and DTE parameters was low. ICC, SEM, and MDC were better when using the mean of the second and the third trials. Spatiotemporal gait parameters obtained from foot-worn inertial sensors assessed in patients with axSpA in single- and dual-task conditions are reliable. However, symmetry and DTE parameters seem less reliable and need to be interpreted with caution. Finally, better reliability of gait parameters was found when using the mean of the 2nd and the 3rd trials.

Gait as predictor of physical function in axial spondyloarthritis: the prospective longitudinal FOLOMI (Function, Locomotion, Measurement, Inflammation) study protocol

Axial spondyloarthritis (axSpA) is a chronic inflammatory rheumatic disease affecting predominantly sacroiliac joints and axial skeleton. axSpA progression being irregular and hardly predictable, identifying functional decline is particularly important in patient with axSpA to allow delivery of timely and targeted interventions. Pain, reduced range of motion or altered posture can have adverse consequences on gait. Although gait has previously been used as a sensitive measure of physical outcomes in elderly and pathological populations, to the best of our knowledge, no study has used gait as a predictor of physical function in patients with axSpA. The objective of our study is hence to determine if gait parameters measured in patients with axSpA could predict the evaluation at 18 months of physical function as assessed by the Bath Ankylosing Spondylitis Functional Index (BASFI). This is a prospective and longitudinal study. Sixty patients with axSpA and 30 healthy age- and sex-matched controls will be included. Patients should be aged 18-65 years at time of their first evaluation, followed at Grenoble Alpes University Hospital for axSpA or ankylosing spondylitis, able to walk 180 m without technical help and with stable treatment for at least 12 months. Clinical characteristics, BASFI, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), clinical and laboratory measurements of gait will be assessed during four visits (at baseline and at months 6, 12, and 18). Similar assessments will be performed once for the healthy control group. A linear mixed model at 6, 12 and 18 months will be constructed to answer to the first objective, with the BASFI as dependent variable and gait parameters as explanatory variables. The data collection started in August 2018 and will be completed with the inclusion and follow-up of all the participants. We believe that the combination of clinical and laboratory measurements of gait in patients with axSpA could strengthen the capacity to monitor disease's evolution and to predict changes in patients' physical function. Results of the present study could ultimately allow delivering targeted, timely, personalized interventions and treatment in patients with axSpA.Trial registration: The study was approved by local ethic committee (CPP Ile De France 1, RCB: 2017-A03468-45, date of agreement: July 17th, last version: V4.0, 2018, March 5th, 2019) and is retrospectively registered in Clinical trials (NCT03761212).