Hip disease in ankylosing spondylitis

Use of double-echo ultrashort echo time magnetic resonance imaging to assess proximal femoral cortical bone changes in axial spondyloarthritis

OBJECTIVE

We quantitatively evaluated proximal femoral cortical bone changes associated with generalized bone loss in axial spondyloarthritis (axSpA) patients using double-echo ultrashort echo time (UTE) MRI. To achieve non-radiation, clinically available visualization of cortical microstructural deterioration in the proximal femur of axSpA and to determine the factors influencing it.

MATERIALS AND METHODS

Patients with axSpA (n = 83) and age- and sex-matched healthy controls (n = 61) were recruited and underwent double-echo UTE MR scan of the nondominant proximal femur. Porosity index (PI) and cortical bone thickness (CbTh) were measured by two radiologists and their average measurements were used for subsequent analyses. Additionally, demographic characteristics of all subjects and disease-specific characteristics of axSpA patients were recorded. Proximal femoral cortical bone PI and CbTh values were compared between axSpA patients and healthy controls using independent samples t-test. Correlation analyses (Pearson or Spearman or Point-biserial correlation coefficients) were conducted to investigate factors potentially associated with UTE measurements in axSpA patients, and Bonferroni correction was applied at the α = 0.002 level for more stringent correction. Multiple linear regression analyses were performed to further identify influencing factors of UTE measurements with multiple correlated variables.

RESULTS

A total of 72 axSpA patients and 52 healthy control subjects were finally included. Patients and control subjects were comparable in sex, age, and body mass index (BMI). Proximal femoral cortical PI was higher (p < 0.001) and CbTh was lower (p < 0.001) in axSpA patients than in healthy controls. Sex (p < 0.001), BMI (p = 0.003), disease duration (p = 0.044), onset age (p = 0.01), alkaline phosphatase (ALP) (p < 0.001), radiographic axSpA (r-axSpA) (p = 0.02), Sacroiliac Joint Structural Score (SSS)-backfill (p = 0.03), SSS-ankylosis (p = 0.01), and nonsteroidal anti-inflammatory drugs (NSAIDs) use (p = 0.03) were potentially correlated to proximal femoral cortical PI, and among them, sex (p < 0.001) and BMI (p = 0.01) were independently associated demographic characteristics, and ALP (p = 0.02), SSS-backfill (p = 0.044) and SSS-ankylosis (p = 0.01) were independently associated disease-specific characteristics, and when all types of variables were considered, sex (p < 0.001), BMI (p = 0.016), and SSS-ankylosis (p = 0.042) were independently associated with PI. BMI (p = 0.043) and NSAIDs use (p = 0.041) were potentially negatively associated with CbTh.

CONCLUSION

Double-echo UTE measurements revealed deteriorated proximal femoral cortical bone microstructure in axSpA patients than controls, potentially associated with sex, BMI, disease duration, onset age, ALP, r-SpA, SSS-backfill, SSS-ankylosis, and NSAIDs use, where sex, BMI, ALP, SSS-backfill and SSS-ankylosis were the independently relevant factors. It offers a novel tool for axSpA's cortical bone assessment.

Factors predisposing to limited flexion after total hip arthroplasty for the treatment of axial spondyloarthritis

Hip involvement is a common condition in about one-third of patients with axial spondyloarthritis (axSpA). We assessed the incidence of possible factors that predispose patients to limited flexion after total hip arthroplasty (THA) for the treatment of axSpA. We retrospectively reviewed 516 patients with axSpA (759 hips) who underwent THA. Baseline patient demographics and clinical, laboratory, and surgery-related parameters were retrospectively collected. The preoperative and latest follow-up Harris hip score (HHS) and hip flexion ability were compared. After documenting the degree of postoperative hip flexion at the latest follow-up visit, we classified hips into good flexion group (> 90°) and poor flexion group (≤ 90°). The differences of baseline parameters between good flexion and poor flexion group were examined. Then those baseline parameters with P < 0.1 in intergroup comparisons were further included into the multivariate logistic models. The median duration of follow-up was 118.5 months (range, 25.0-269.1 months). The median HHS increased from 36.0 (25.0, 44.0) before surgery to 85.0 (77.0, 92.0) at the latest follow-up visit (P < 0.001). At the latest follow-up visit, 406 hips (53.5%) had hip flexion > 90°. The patients who were somewhat dissatisfied represented 147 hips (19.4%), and those who were very dissatisfied represented 46 hips (6.1%). The primary cause of dissatisfaction was limited range of motion (ROM) (323 hips, 80.1%). The multivariate logistic regression model revealed that the significant variables for postoperative poor hip flexion were the younger age of disease onset (OR = 0.967; P = 0.024), psoriasis (PSO) (OR = 2.071; P = 0.007), elevated C-reactive protein (CRP) (OR = 1.031; P < 0.001), and the lack of direct anterior approach (DAA) (OR = 0.372; P = 0.015). Although THA reconstruction for axSpA patients with end-stage hip involvement achieved encouraging clinical outcomes, it was prone to a restriction of hip flexion, which is closely associated with patient satisfaction. The younger age of disease onset, PSO, elevated CRP and the lack of DAA were significantly associated with limited postoperative hip flexion. Key Points • The restriction of hip flexion after THA reconstruction for axSpA patients is closely associated with patient satisfaction. • The younger age of disease onset, PSO, elevated CRP and the lack of DAA were significantly associated with limited postoperative hip flexion.

Axial radiographic structural damage in patients with Enthesitis-Related Arthritis presents a distinct phenotype compared to adults with axial spondyloarthritis: A cross-sectional cohort study

Enthesitis-related arthritis (ERA), a distinct subtype of juvenile idiopathic arthritis (JIA) related to HLA-B27 and peripheral and axial involvement, presents with insidious onset of arthritis and/or enthesitis. However, there is a lack of data concerning axial new bone formation in patients transitioning into adulthood. To evaluate the axial radiographic structural damage (axRxSD), encompassing the sacroiliac joints (SIJ), hips, and spine, in ERA patients across various age groups. A cross-sectional cohort study was conducted with patients aged up to 35 years. Specific tools were used for measuring disease activity (BASDAI, ASDAS), function (BASFI, HAQ-S), mobility (BASMI), clinical enthesitis (MASES), ultrasound evaluation (MASEI), and axRxSD, including mSASSS for spine, Kellgren-Lawrence for hips and modified New York criteria for SIJ. A total of 26 patients were included, of whom 76.9% were males, with a mean age at diagnosis and assessment of 11.9 and 19.7 years, respectively. HLA-B27 positivity was found in 58.3%. Current active arthritis and enthesitis were present in 19.2% and 23%, respectively, with mean MASEI score of 12 (IQR 6-17). Peripheral joint limitation was observed in 50%, despite a BASMI score of 2.2 and 16% occurrence of abnormal FABER test. Most patients were in remission or low disease activity [ASDAS-ESR = 1.2 (0.6-2.3); ASDAS-CRP = 1.55 (0.6-2.4)]. Modified New York criteria were fulfilled by 73.1% of patients and 15.4% had radiographic hip involvement. Spine involvement, measured by mSASSS, was low (IQR 0-4.2), with only two patients exhibiting syndesmophytes. There was no statistical association between any imaging methods and clinical, laboratory, and ultrasound variables, including scores for activity, functionality, and mobility. Significant association was found only between axRxSD and BASMI. Our results showed high frequency of SIJ ankylosis alongside lower radiographic involvement in the spine and hips, suggesting a distinct structural damage phenotype. The early recognition of this outcome and the use of immunobiological therapy may mitigate syndesmophyte occurrence over time.

Precise Acetabular Prosthesis Positioning Using a Novel Robot-Assisted Total Hip Arthroplasty System: A Multicenter, Randomized Controlled Trial

OBJECTIVE

Total hip arthroplasty (THA) is currently one of the most effective treatment methods for end-stage hip joint disease, and its long-term effectiveness largely depends on the accurate placement of the acetabular prosthesis. In conventional surgery, the placement of the acetabular prosthesis mainly relies on the surgeon's clinical experience and surgical techniques. To further improve the accuracy of prosthesis placement, a new robotic system for THA is designed. The purpose of this study is to verify the effectiveness and safety of THA assisted by this robotic system.

METHOD

A multicenter, prospective, randomized controlled, superiority study design was adopted with statistical methods of t test and Chi-squared test. Participants undergoing primary THA have been enrolled in three centers of joint surgery in China since July 17, 2023. Robotic THA was operated in the experimental group, and conventional instruments were used in the control group. The primary outcome is the proportion of anteversion and inclination angles in the safe zone. The secondary outcomes include operation time, WOMAC score, Harris score, SF-36 health questionnaire, dislocation rate of hip joint, and rates of adverse events and serious adverse events.

RESULTS

A total of 138 patients were included in this study. The proportion of both anteversion and inclination angles in the safe zone was 92.2% in the experimental group and 50.8% in the control group, with significant difference (p < 0.01). The average operation time in the experimental group and control group was 116.4 and 80.5 min respectively, with significant difference (p < 0.01). There was no significant difference in WOMAC score, Harris score, and SF-36 between the two groups (6 ± 2) weeks after operation (p > 0.05). The dislocation rate of hip joint in the experimental group and control group were 3.0% and 1.5%, respectively, without significant difference (p > 0.05). The rate of adverse events and severe adverse events in the experimental group and control group also showed no significant difference (p > 0.05). No adverse events or serious adverse events were judged to be "definitely related" to the experimental instruments.

CONCLUSION

Robotic THA could prolong the operation time within an acceptable range, but more precise acetabular prosthesis positioning could be obtained when compared with conventional surgery. Besides, no significant difference was found in function scores, dislocation rate or other adverse events, which indicates that this new robot system shows both good effectiveness and safety in THA.

TRIAL REGISTRATION

Clinical Trials: NCT05947734.

Therapeutic Potential of Bee and Wasp Venom in Anti-Arthritic Treatment: A Review

Arthritis has a high global prevalence. During the early ancient human era, bee (Apis) venom therapy was employed in Egypt, Greece, and China to alleviate ailments such as arthritis and neuralgia. In addition, bee venom has long been used as a traditional medicine for immune-related diseases in Korea. Wasp (Vespa) venom is a folk medicine of the Jingpo people in Yunnan, China, and has been widely used to treat rheumatoid arthritis. In spite of this, the underlying mechanisms of bee and wasp venoms for the treatment of arthritis are yet to be fully understood. In recent years, researchers have investigated the potential anti-arthritic properties of bee and wasp venoms. Studies have shown that both bee and wasp venom can improve swelling, pain, and inflammation caused by arthritis. The difference is that bee venom reduces arthritis damage to bone and cartilage by inhibiting the IRAK2/TAK1/NF-κB signaling pathway, NF-κB signaling pathway, and JAK/STAT signaling pathway, as well as decreasing osteoclastogenesis by inhibiting the RANKL/RANK signaling pathway. Wasp venom, on the other hand, regulates synovial cell apoptosis via the Bax/Bcl-2 signaling pathway, inhibits the JAK/STAT signaling pathway to reduce inflammation production, and also ameliorates joint inflammation by regulating redox balance and iron death in synovial cells. This review provides a detailed overview of the various types of arthritis and their current therapeutic approaches; additionally, it comprehensively analyzes the therapeutic properties of bee venom, wasp venom, or venom components used as anti-arthritic drugs and explores their mechanisms of action in anti-arthritic therapy.

Radiomics-based machine learning model to phenotype hip involvement in ankylosing spondylitis: a pilot study

Objectives

Hip involvement is an important reason of disability in patients with ankylosing spondylitis (AS). Unveiling the potential phenotype of hip involvement in AS remains an unmet need to understand its biological mechanisms and improve clinical decision-making. Radiomics, a promising quantitative image analysis method that had been successfully used to describe the phenotype of a wide variety of diseases, while it was less reported in AS. The objective of this study was to investigate the feasibility of radiomics-based approach to profile hip involvement in AS.

Methods

A total of 167 patients with AS was included. Radiomic features were extracted from pelvis MRI after image preprocessing and feature engineering. Then, we performed unsupervised machine learning method to derive radiomics-based phenotypes. The validation and interpretation of derived phenotypes were conducted from the perspectives of clinical backgrounds and MRI characteristics. The association between derived phenotypes and radiographic outcomes was evaluated by multivariable analysis.

Results

1321 robust radiomic features were extracted and four biologically distinct phenotypes were derived. According to patient clinical backgrounds, phenotype I (38, 22.8%) and II (34, 20.4%) were labelled as high-risk while phenotype III (24, 14.4%) and IV (71, 42.5%) were at low risk for hip involvement. Consistently, the high-risk phenotypes were associated with higher prevalence of MRI-detected lesion than the low-risk. Moreover, phenotype I had significant acute inflammation signs than phenotype II, while phenotype IV was enthesitis-predominant. Importantly, the derived phenotypes were highly predictive of radiographic outcomes of patients, as the high-risk phenotypes were 3 times more likely to have radiological hip lesion than the low-risk [27 (58.7%) vs 16 (28.6%); adjusted odds ratio (OR) 2.95 (95% CI 1.10, 7.92)].

Conclusion

We confirmed for the first time, the clinical actionability of profiling hip involvement in AS by radiomics method. Four distinct phenotypes of hip involvement in AS were identified and importantly, the high-risk phenotypes could predict structural damage of hip involvement in AS.

The state of bone mineral density in men with ankylosing spondylitis and its relationship with the course of the disease

Introduction

The aim of the study was to study the structural and functional state of bone tissue in men with ankylosing spondylitis (AS) and to assess its relationship with the course of the disease.

Material and methods

A study was conducted with the participation of 105 men with AS aged from 22 to 59 years (average age was 40.7 ±0.8 years) with a duration of the disease of 8.7 ±0.5 years and 29 persons of the control group. Disease activity and the degree of functional limitations were determined by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Activity Score correlated with C-reactive protein (ASDAS-CRP) and the Bath Ankylosing Spondylitis Functional Index (BASFI). Laboratory examination included determination of C-reactive protein (CRP). Bone mineral density (BMD) of the lumbar spine and femoral neck was determined by the method of dual-energy X-ray absorptiometry on the Hologic Discovery Wi device (S/N 87227).

Results

In men with AS, a decrease in BMD (according to the Z-score and T-score) was found in 41.9%, while the percentage of patients with osteoporosis at the level of the femoral neck and lower back was 16.7%. Development of osteoproliferative changes was observed in 42 (40%) patients. Bone mass loss was associated with high activity of the inflammatory process according to ASDAS, BASDAI (r = -0.39, -0.65), and CRP (r = -0.28, -0.38) and low functional capacity according to BASFI (r = -0.27, -0.59), while syndesmophytosis had a reliable association with the age of the patients, the duration of the disease and low functional capacity. Low-energy fractures occurred in 11.4% of men with AS. The presence of fractures was associated with high disease activity (ASDAS, BASDAI, CRP) and was not related to the age of the patients or duration of the disease.

Conclusions

A decrease in BMD and the development of fractures were closely associated with high activity of the inflammatory process and low functional capacity, while syndesmophytosis was related to the age of patients and the duration of the disease.

Association of radiological severity of hip involvement with clinical characteristics and sagittal spinopelvic balance in patients with ankylosing spondylitis

INTRODUCTION

This is the first study to analyze the associations between the radiological severity of hip involvement with clinical characteristics and sagittal spinopelvic balance in patients with ankylosing spondylitis (AS).

METHOD

We evaluated 182 patients with AS who were referred to outpatient clinics. Patient demographic data and clinical and radiographic parameters were collected. Patients were divided into three groups based on the Bath Ankylosing Spondylitis Radiology Hip Index. Clinical characteristics and spinopelvic parameters acquired by a low-dose biplanar imaging system were evaluated among these groups.

RESULTS

Patients with more severe hip involvement were older and had longer disease duration and diagnostic delay, with lower Harris Hip Score (p < 0.001) and 12-item Short Form Health Survey Physical Component Score (p < 0.001) and higher Bath Ankylosing Spondylitis Disease Activity Index (p = 0.030) and Functional Index (p < 0.001). Patients with more severe hip involvement had significantly higher sacroiliac grade (p < 0.001) and higher modified Stoke Ankylosing Spondylitis Spinal Score (p < 0.001). Patients with moderate and severe hip involvement had similar lumbar lordosis and spino-sacral angle, whereas patients with severe hip involvement had lower pelvic tilt, pelvic femoral angle, higher sacral slope, and sagittal vertical axis.

CONCLUSIONS

The severity of hip involvement is associated with physical function and is not consistent with the severity of spinal involvement. Severe hip involvement impairs the ability to retrovert the pelvis to accommodate the sagittal deformity, and spinopelvic parameters should be concretely evaluated in preoperative counseling of patients with AS waiting for total hip arthroplasty. Key Points • The severity of hip involvement in patients with AS is associated with physical function. • Severe hip involvement impairs the ability to retrovert the pelvis to accommodate the sagittal deformity.

Exploring physical function and physical activity in axial spondyloarthritis: Beyond clinical remission or low disease activity

OBJECTIVES

To investigate the crucial roles of physical function (PF) and physical activity (PA) in axial spondyloarthritis (axSpA) patients, as well as their correlation with disease activity (DA), and to explore the influence of general characteristics among them.

METHODS

We enrolled axSpA patients from Xijing Hospital, spanning March 2022 to August 2022. Spearman rank correlation coefficients were used to assess correlations between PA (measured by the Global Physical Activity Questionnaire [GPAQ]), PF (measured by the Assessment of Spondyloarthritis international Society Health Index [ASAS-HI], the Short Form 36-Item Health Survey [SF-36], and the Bath Ankylosing Spondylitis Functional Index [BASFI]), DA, and their influencing factors. A Mann-Whitney U-test and Kruskal-Wallis H-test were used to compare variables between different patients grouped by sex, human leukocyte antigen B27 (HLA-B27), hip involvement, and intensity of PA and DA.

RESULTS

Three hundred fifty-five axSpA patients were included. We observed a moderate to strong correlation between DA and PF in axSpA patients. PA was weakly correlated with DA or PF. DA varied significantly at different PA levels, and patients with low PA levels had poorer PF. Active patients had worse PF, less transport-related PA, and a higher rate of hip involvement with a worse Harris Hip Score (HHS).

CONCLUSIONS

We identified a close relationship between DA, PF, and PA in axSpA patients. Further, gender, HLA-B27, and hip involvement affected the clinical manifestation of axSpA patients. These findings demonstrate that clinical remission of axSpA patients requires a comprehensive assessment rather than a single remission of DA.

Management of Specific Clinical Profiles in Axial Spondyloarthritis: An Expert's Document Based on a Systematic Literature Review and Extended Delphi Process

INTRODUCTION

The management of specific clinical scenarios is not adequately addressed in national and international guidelines for axial spondyloarthritis (axSpA). Expert opinions could serve as a valuable complement to these documents.

METHODS

Seven expert rheumatologists identified controversial areas or gaps of current recommendations for the management of patients with axSpA. A systematic literature review (SLR) was performed to analyze the efficacy and safety of non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, conventional synthetic, biologic and targeted synthetic disease-modifying antirheumatic drugs (csDMARDs, b/tsDMARDs) in axSpA regarding controversial areas or gaps. In a nominal group meeting, the results of the SLR were discussed and a set of statements were proposed. A Delphi process inviting 150 rheumatologists was followed to define the final statements. Agreement was defined as if at least 70% of the participants voted ≥ 7 (from 1, totally disagree, to 10, totally agree).

RESULTS

Three overarching principles and 17 recommendations were generated. All reached agreement. According to them, axSpA care should be holistic and individualized, taking into account objective findings, comorbidities, and patients' opinions and preferences. Integrating imaging and clinical assessment with biomarker analysis could also help in decision-making. Connected to treatments, in refractory enthesitis, b/tsDMARDs are recommended. If active peripheral arthritis, csDMARD might be considered before b/tsDMARDs. The presence of significant structural damage, long disease duration, or HLA-B27-negative status do not contraindicate for the use of b/tsDMARDs.

CONCLUSIONS

These recommendations are intended to complement guidelines by helping health professionals address and manage specific groups of patients, particular clinical scenarios, and gaps in axSpA.

Risk factors of hip joint structural changes following pedicle subtraction osteotomy for ankylosing spondylitis-related thoracolumbar kyphosis: a minimum two-year observation

PURPOSE

To determine the clinical- and surgical-related factors of hip joint structural changes in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis who underwent PSO.

METHODS

Hip involvement was assessed by the Bath Ankylosing Spondylitis Radiology Hip Index (BASRI-h) and defined by a score of at least 2. 52 patients with BASRI-h scores maintained and 78 patients with BASRI-h scores increased during follow-up were retrospectively reviewed. Clinical data were recorded. Radiological assessment was performed preoperatively, postoperatively, and at the final follow-up.

RESULTS

No significant difference existed in age, gender and follow-up time between the groups, but earlier onset of AS, longer disease and kyphotic duration, and worse Bath Ankylosing Spondylitis Functional Index (BASFI) scores at the final follow-up were observed in patients with BASRI-h scores increased (P < 0.05). Besides, global kyphosis (GK), T1-pelvic angle (TPA), pelvic tilt (PT) and anterior pelvic plane angle (APPA) were always larger in patients with BASRI-h scores increased, accompanied with more sacral fixation (P < 0.05). Multivariate logistics regression showed that earlier onset of AS, longer kyphotic duration, larger preoperative GK, sacral fixation and larger APPA during follow-up were independent risk factors.

CONCLUSION

Earlier onset of AS and longer kyphotic duration were the clinical risk factors of hip joint structural changes in AS patients following PSO, while larger preoperative GK, sacral fixation in PSO and larger APPA during follow-up were the surgical-related factors. Surgeons should inform patients with risk factors of the possibility for severe hip joint structural changes after PSO.

New genomic insights into the conformation of Lipizzan horses

Conformation traits are important selection criteria in equine breeding, as they describe the exterior aspects of the horse (height, joint angles, shape). However, the genetic architecture of conformation is not well understood, as data of these traits mainly consist of subjective evaluation scores. Here, we performed genome-wide association studies on two-dimensional shape data of Lipizzan horses. Based on this data, we identified significant quantitative trait loci (QTL) associated with cresty neck on equine chromosome (ECA)16 within the MAGI1 gene, and with type, hereby differentiating heavy from light horses on ECA5 within the POU2F1 gene. Both genes were previously described to affect growth, muscling and fatty deposits in sheep, cattle and pigs. Furthermore, we pin-pointed another suggestive QTL on ECA21, near the PTGER4 gene, associated with human ankylosing spondylitis, for shape differences in the back and pelvis (roach back vs sway back). Further differences in the shape of the back and abdomen were suggestively associated with the RYR1 gene, involved in core muscle weakness in humans. Therefore, we demonstrated that horse shape space data enhance the genomic investigations of horse conformation.

Thrombocytosis in patients with spondyloarthritis: a case-control study

OBJECTIVE

This study aimed to investigate the clinical and laboratory as well as radiological features of spondyloarthritis (SpA) patients with thrombocytosis and to explore risk factor for thrombocytosis in SpA patients and to assess the effect of antitumor necrosis factor-α (anti-TNF-α) therapy on platelet count in SpA patients with thrombocytosis.

METHODS

A total of 145 patients with SpA were included in this study, and non-thrombocytosis was identified in 76 patients while thrombocytosis was found in 69 patients, 38 out of the 69 patients received anti-TNF-α therapy. Logistic regression analysis was performed to investigate risk factors that associated with thrombocytosis. The platelet count of patients in the thrombocytosis group treated with anti-TNF-α therapy on week 0, week 6 and week 12 were collected and compared with conventional therapy group.

RESULTS

The proportion of hip involvement (60.86% vs 36.84%, p = 0.004), bath ankylosing spondylitis disease activity index score (4.24 ± 0.55 vs 3.69 ± 0.67, p < 0.001), erythrocyte sedimentation rate (62.22 ± 41.97 mm/hour vs 27.00 ± 25.93 mm/hour, p < 0.001), C-reactive protein (53.45 ± 47.45 mg/L vs 18.91 ± 31.09 mg/L, p < 0.001), fibrinogen (5.77 ± 1.48 g/L vs 4.01 ± 1.32 g/L, P < 0.001), white blood cells (8.15 ± 1.90 × 10⁹/L vs 6.85 ± 2.39 × 10⁹/L, p < 0.001) and neutrophils (5.08 ± 1.55 × 10⁹/L vs 4.01 ± 2.04 × 10⁹/L, p = 0.001) are higher in thrombocytosis group, but hemoglobin and albumin are lower compared to non-thrombocytosis group (122.88 ± 17.25 g/L vs 131.51 ± 16.03 g/L, p = 0.002; 37.19 ± 4.73 g/L vs 39.67 ± 3.99 g/L, p = 0.001, respectively). Multivariable logistic regression analysis indicated that higher white blood cells (OR, 1.644; 95% CI, 1.045-2.587; P = 0.032) and fibrinogen (OR, 2.169; 95% CI, 1.237-3.804; P = 0.007) were independently associated with thrombocytosis in SpA patients. The platelet count in the thrombocytosis group treated with anti-TNF-α therapy on week 6 and week 12 were statistically lower than week 0 (225.05 ± 60.58 × 10⁹/L vs 368.26 ± 54.34 × 10⁹/L, p < 0.001; 201.26 ± 51.48 × 10⁹/L vs 368.26 ± 54.34 × 10⁹/L, p < 0.001) and conventional therapy (week 6, 225.05 ± 60.58 × 10⁹/L vs 370.00 ± 74.05 × 10⁹/L, p < 0.001; week 12, 201.26 ± 51.48 × 10⁹/L vs 303.13 ± 71.49 × 10⁹/L, p < 0.001).

CONCLUSION

SpA patients with thrombocytosis have a higher proportion of hip involvement and disease activity compared to non-thrombocytosis SpA patients. The potential risk factors for thrombocytosis in SPA patients were higher white blood cells and fibrinogen. Anti-TNF-α therapy can reduce the increased platelets more effectively and rapidly than conventional treatments in SpA patients with thrombocytosis.

Patient-tailored dose reduction of tumor necrosis factor inhibitors in axial spondyloarthritis

Tumor necrosis factor inhibitors have been widely used in the field of axial spondyloarthritis, with current guidelines now recommending dose reduction instead of withdrawal of biologics. Systemic review and meta-analyses in literature have summarized present tapering strategies and principles in published heterogeneous studies. In this study, we reviewed and provided an update on present evidence based on prospective and retrospective studies from 2008 to 2022 by performing a literature review of related publications on remission or relapse from PubMed. We further stated the core issues concerning dose reduction, including the timing, optimization, intensity, maintenance, monitoring, factors associated with tapering and solutions to de-escalation failure. Remission/relapse should be the principal consideration in dose reduction implementation for individuals without comorbidities. As a treat-to-target scope of this multifaceted systemic disease, extra-articular manifestations such as uveitis, psoriasis, inflammatory bowel disease, cardiovascular complication, hip involvement and progressed structural damage influence patient-tailored dose reduction plans. Safety concerns and costs should be integrated into the decision-making schedule to optimize the individualized dose reduction paradigm.

A Cross-Sectional Study on Gluteal Muscles in Patients with Ankylosing Spondylitis at Different Stages of Hip Involvement

Hip involvement in ankylosing spondylitis (AS) is associated with severe functional impairment, and early diagnosis can improve the disease prognosis. We investigated gluteal muscle cross-sectional area (CSA) and radiodensity at different stages of hip involvement and their associations with AS-related clinical and laboratory parameters. This cross-sectional study included 83 patients with AS and 83 age- and sex-matched controls. Patients with AS were divided into three groups according to the Bath Ankylosing Spondylitis Radiology Hip Index system. The CSA and radiodensity of the gluteus maximus, medius, and minimus muscles were measured using computed tomography images. Muscle parameters were compared, and their relationships with clinical and laboratory parameters were evaluated. For the gluteus maximus, patients with AS had a lower CSA than controls, regardless of the degree of hip involvement. For the gluteus medius and minimus, patients with moderate/advanced hip involvement had significantly lower CSA and radiodensity than those with mild to no hip involvement. The severity of hip involvement was negatively associated with muscle parameters. CSA of the gluteus maximus decreased in early-stage hip involvement without any changes in radiographs, while radiodensity decreased in the later stages. Muscle parameters on computed tomography may be a more sensitive indicator than radiographic findings.

Deep-learning based quantification model for hip bone marrow edema and synovitis in patients with spondyloarthritis based on magnetic resonance images

Objectives: Hip inflammation is one of the most common complications in patients with spondyloarthritis (SpA). Herein, we employed use of a deep learning-based magnetic resonance imaging (MRI) evaluation model to identify irregular and multiple inflammatory lesions of the hip. Methods: All of the SpA patients were enrolled at the Xijing Hospital. The erythrocyte sediment rate (ESR), C-reactive protein (CRP), hip function Harris score, and disease activity were evaluated by clinicians. Manual MRI annotations including bone marrow edema (BME) and effusion/synovitis, and a hip MRI scoring system (HIMRISS) assessment was performed by experienced musculoskeletal radiologists. The segmentation accuracies of four deep learning models, including U-Net, UNet++, Attention-Unet, and HRNet, were compared using five-fold cross-validation. The clinical agreement of U-Net was evaluated with clinical symptoms and HIMRISS results. Results: A total of 1945 MRI slices of STIR/T2WI sequences were obtained from 195 SpA patients with hip involvement. After the five-fold cross-validation, U-Net achieved an average segmentation accuracy of 88.48% for the femoral head and 69.36% for inflammatory lesions, which are higher than those obtained by the other three models. The UNet-score, which was calculated based on the same MRI slices as HIMRISS, was significantly correlated with the HIMRISS scores and disease activity indexes (p values <0.05). Conclusion: This deep-learning based automatic MRI evaluation model could achieve similar quantification performance as an expert radiologist, and it has the potential to improve the accuracy and efficiency of clinical diagnosis for SpA patients with hip involvement.

Intraoperative picture of hip joint lesion in ankylosing spondylitis: data from a retrospective analysis

In population of Russian patients with ankylosing spondylitis (AS), the frequency of clinical manifestations (pain and limitation of functions) of coxitis reaches 56%. Total hip arthroplasty (THA) can be considered as the only alternative that can relieve the suffering of the patient. Radiography and magnetic resonance imaging are widely used methods for assessing structural damage to the hip joint in AS. However, at the moment these methods can’t allow us to fully describe the lifetime changes of these joints. The aim of the study: to analyze the external changes of the femoral heads (HF) and acetabulums during the THA in patients with AS. Materials and methods. The retrospective study included 170 patients with a reliable diagnosis of AS, who met the modified New York criteria of 1984, who were treated in the traumatological and orthopedic department of the V.A. Nasonova Research Institute of Rheumatology in the period from 1998 to 2020, all patients underwent THA as planned. Most of them were male (80.6%). The average age of patients was 38.1±11.3 years and the average duration of the disease since the onset of the first symptoms was 17.0±8.5 years. The duration of pain in hip joints before performing THA is 7.4±4.8 years. The assessment of macroscopic changes in the FH and acetabulum was performed intraoperatively. Results and discussion. Acetabulum protrusion was detected in 108 (63.5%) patients, bone cysts – in 65 (38.2%). Filling of acetabulum with granulation tissue was recorded in 155 (91.2%) patients, presence of osteophytes on its edges – in 153 (90%). Cartilage in the acetabulum was completely absent in 122 (71.8%) patients. FH deformation was detected in 98.2% of cases, erosion in 46.4%. Cartilage on FH was completely absent in 130 (76.5%) patients. In 119 (70%) patients, macroscopic signs of osteonecrosis of FH were found. 79 (46.4%) patients had ankylosis of the hip joint, including fibrous ankylosis – in 77.2% of patients and bone ankylosis – in 22.8%. Conclusion. In patients with AS, the necessity for THA occurs on average after 7.4±4.8 years from the moment of the appearance of first clinical signs of coxitis. In 70% of cases, the macroscopic picture of hip joint lesion was characterized by the development of Avascular necrosis of the femur head (AVNFH), in most patients there was no cartilage in the most loaded segments of acetabulum and FH, in almost half of cases – ankylosis of hip joint and mainly fibrous (77.2%).

Age and Symptoms at Onset of Ankylosing Spondylitis in Japanese Patients

OBJECTIVE

To examine the age at onset and initial symptoms as clinical features of ankylosing spondylitis (AS) in Japanese patients.

METHODS

This retrospective study included 60 Japanese patients diagnosed with AS at our institute between January 2004 and June 2021. Initial symptoms were considered pain in axial joints and/or extra-axial joints. If a patient had initial symptoms at multiple sites, each site was counted. We assessed trends for the number of patients and sites of initial symptoms according to age at onset.

RESULTS

Mean age (± standard deviation) at onset was 28.9 (± 14.3) years. Approximately one-third of patients experienced onset before age 20. The back was the most common site of initial symptoms (36.7%), followed by the hip (26.7%), knee (15%), buttocks (15%), neck (10%), finger (6.7%), shoulder (3.3%), and others (including overlapping sites). Thirty-two (53.3%) and 25 (41.7%) patients had initial symptom only in axial joints and only in extra-axial joints, respectively. The proportion of patients with initial symptoms only in extra-axial joints significantly decreased with increasing age (p=0.024).

CONCLUSION

Sites of initial symptoms were frequently the back, hip, knee, and buttocks, and 41.7% had initial symptom only in extra-axial joints. Younger onset patients frequently had extra-axial involvement.

Fourth-Generation Ceramic-on-Ceramic THA in Patients with Ankylosing Spondylitis: A Minimum 10-Year Follow-Up

OBJECTIVE

To report the long-term outcomes of total hip arthroplasty (THA) with fourth-generation ceramic-on-ceramic (CoC) bearing in patients with ankylosing spondylitis (AS).

METHODS

We retrospectively identified 180 primary THAs performed in 110 patients with AS, including 100 (90.9%) men and 10 women (9.1%), from 2009 to 2011.The mean age of the patients at surgery was 33 years (range, 16 to 65 years). Cementless prostheses with fourth-generation CoC bearings were used in all patients. Survivorship of the implants and postoperative complications were calculated. Functional improvement was assessed by the hip flexion-extension range of motion (ROM) and Harris hip score (HHS). A special noise assessment questionnaire was performed at the last follow-up. The cumulative incidence of noise was calculated by the Kaplan-Meier method with 95% confidence intervals (CIs). Clinical characteristics and functional outcomes were compared in the hips with noise to those without noise.

RESULTS

The mean follow-up was 11 years (range, 10 to 12 years), and survivorship of the implants was 99.4% at the most recent follow-up. The complications included dislocation (one hip, 0.6%), periprosthetic joint infection (one hip, 0.6%), mild to moderate pain (five hips, 2.8%), heterotopic ossification (12 hips, 6.7%), and noise (52 hips, 28.9%). The flexion-extension ROM improved significantly with a median from 10° (range, 0 ~ 130°) to 100° (30 ~ 130°) after THA (p < 0.001), and the HHS increased significantly from 41 ± 20 to 90 ± 8 (p < 0.001). The cumulative incidence of noise at 0.5, 5, and 10 years was 6.1% (95% CI, 2.6 ~ 9.6), 16.7% (95% CI, 11.2 ~ 22.1), and 28.9% (95% CI, 22.2 ~ 35.5), respectively, and that of squeaking at 0.5, 5, and 10 years was 4.4% (95% CI, 1.4 ~ 7.4), 13.3% (95% CI, 8.4 ~ 18.3), and 23.9% (95% CI, 17.6 ~ 30.1), respectively. None of the patients with noise generation in the hip reported it affecting daily activities or causing dissatisfaction. No differences in age, sex, BMI, disease duration, bilateral THA, the frequency of bony ankylosis, the proportion of using a 36-mm-diameter femoral head, pre/postoperative flexion-extension ROM, or pre/postoperative HHS were found between hips with noise and those without noise (p > 0.05).

CONCLUSION

THAs with fourth-generation CoC bearings exhibit excellent long-term survival and clinical outcomes in patients with AS, with a very low dislocation rate. The incidence of noise associated with CoC bearings in THA performed in patients increases over time, but it does not affect postoperative hip function or daily activities.

Multiparametric Large Field of View Rheumatology Imaging for Axial Spondyloarthropathy Detects Enthesitis in Setting of Inactive Sacroiliac Joint Disease and Impacts Clinical Diagnosis

AIM

To test the diagnostic efficacy of a multiparametric rheumatology lumbosacral magnetic resonance (MR) imaging protocol in detection and characterization of axial spondylarthritis (SpA) and compare it with serology and clinical findings.

METHODS

A consecutive series of multiparametric rheumatology lumbosacral MR imaging examinations performed on 3T MR scanner. Three-dimensional inversion recovery turbo spin echo, precontrast and postcontrast fat-suppressed T1-weighted images, as well as diffusion-weighted images were used to detect active erosions and enthesitis using established criteria. Pearson χ2 was used for categorical variables. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were measured for magnetic resonance imaging (MRI) and serology, based on the final diagnosis from rheumatologists. An alpha error below 0.05 was considered statistically significant.

RESULTS

The final study sample included 130 consecutive patients (80 women and 50 men; mean ± SD 44 ± 13 and 45 ± 14 years, respectively). Seventy-eight subjects were diagnosed with axial SpA and 52 with non-SpA arthropathy. In the non-SpA group, 27 patients were diagnosed with osteoarthritis, 6 had unremarkable imaging, whereas 19 were considered as clinically undetermined. There was positive correlation between positive MRI results and SpA diagnosis (P < 0.00001). No correlation existed between positive serology alone and SpA diagnosis (P = 0.0634). Although MRI and serology proved equally sensitive in detecting SpA, the specificity and overall accuracy of MRI were significantly higher. Inflammatory activity was detected in 45 (57.7%) cases, in the pelvic enthesis in 29 (37.2%) cases, in the lumbosacral spine in 16 (20.5%) cases, in the hip joints in 15 (19.2%) cases, and in the pubic symphysis in 5 (6.4%). Inactive sacral disease was seen in 7 of 35 enthesitis patients (20.0%), and in 2 SpA cases, there were no sacral lesions.

CONCLUSIONS

The results suggest that in patients with suspected SpA, MRI should not be limited to the sacroiliac joints, but also include enthesitis sites and other joints of the axial skeleton. The multiparametric rheumatology protocol increases the efficacy of MRI in detecting enthesitis and joint inflammatory disease, thereby offering additional information to the clinician and assisting in the early diagnosis/detecting disease activity.

Gender Differences in Ankylosing Spondylitis Patients with Advanced Hip Involvement: Results from A Matched Retrospective Cohort Study

OBJECTIVE

To determine the gender differences in ankylosing spondylitis (AS) patients with advanced hip involvement.

METHODS

We retrospectively analyzed the 373 consecutive AS patients with advanced hip involvement from 2012 to 2017 and divided them into two groups by sex with 340 men and 33 women. Research data on hip involvement in the patients were obtained from medical records and radiographs. The severity of radiographic hip involvement was evaluated by the Bath Ankylosing Spondylitis Radiology Hip Index (BASRI-hip) scoring system. The data on clinical characteristics, radiographic hip involvement, and laboratory values were compared between the two groups. The comparison was performed again between the two groups after adjusting for the onset age and disease duration by propensity score matching (PSM).

RESULTS

Men underwent total hip arthroplasty earlier than women in the patients, with a median age of 31 years (range, 19-67 years) vs 36 years (range, 23-67 years), respectively (P < 0.05). Hip involvement was found to be younger in men than that in women, with a median age of 18 years (range, 7-56 years) vs 23 years (range, 5-55 years) (P < 0.05), and men with bilateral onset in hips had a higher frequency than women with that (66.2% vs 39.4%) (P < 0.05). There was no gender difference in the proportion of bilateral advanced hip involvement (85.3% vs 72.7%) (P > 0.05). The proportion of the patients who had spinal involvement (89.1% vs 69.7%), flexion contracture in the hip (43.8% vs 24.2%), hip range of motion =0° (53.5% vs 30.3%), and an elevated level of C-reactive protein (CRP) (69.1% vs 51.5%) was significantly higher in men than that in women (P < 0.05). After adjusting for the onset age and disease duration by PSM (1:1), men with bilateral onset in hips still had a higher frequency than women with that (76.7% vs 40.0%), and the proportion of the patients who had spinal involvement (90.0% vs 66.7%) and an elevated level of CRP (80.0% vs 53.3%) was significantly higher in men than that in women (P < 0.05).

CONCLUSIONS

The disease pattern of hip involvement in AS has gender differences, with bilateral onset being the dominant pattern in men and unilateral onset being more common in women. However, the frequency of bilateral advanced hip involvement has no gender difference eventually. The higher prevalence of spinal involvement in men with AS may be responsible for the more severe functional impairment compared with women.

The correlation between volumetric bone mineral density and morphological parameters of the proximal femur and clinical outcomes in ankylosing spondylitis patients with hip involvement

Background

To measure volumetric bone mineral density (vBMD) with quantitative computed tomography (QCT) in the proximal femur of ankylosing spondylitis (AS) patients with hip involvement and analyze their correlations with radiographic and clinical parameters.

Methods

Sixty-five AS inpatients were enrolled in this study. The bone mineral density was measured by QCT and dual-energy x-ray absorptiometry (DXA), respectively. The morphological parameters of the proximal femur were measured on digital anteroposterior (AP) radiographs of the pelvis. The correlations between them were analyzed by SPSS software.

Results

The average trabecular vBMD measured at the femoral neck was 136.38 ± 25.58 mg/cm³. According to the BASRI-Hip score, group A consisted of 39 hips (0–2 score) and group B consisted of 26 hips (3–4 score). There were significant differences regarding trabecular CTXA equivalent T-score between group A and B at the femoral neck (p = 0.004); intertrochanteric region (p < 0.001) and greater trochanter (p = 0.001). The trabecular CTXA equivalent T-score at femoral neck had a negative correlation with disease duration (r = − 0.311, p = 0.012) and with CBR (r = − 0.319, p = 0.010).

Conclusions

The low trabecular bone density at the site of the hip was associated with the duration of disease progression and degree of hip involvement. Meanwhile, it had a correlation with hip function status although we failed to confirm a significant relationship between hip vBMD and disease activity.

Total hip arthroplasty in fused hips with spine stiffness in ankylosing spondylitis

Ankylosing spondylitis (AS) is characterized by involvement of the spine and hip joints with progressive stiffness and loss of function. Functional impairment is significant, with spine and hip involvement, and is predominantly seen in the younger age group. Total hip arthroplasty (THA) for fused hips with stiff spines in AS results in considerable improvement of mobility and function. Spine stiffness associated with AS needs evaluation before THA. Preoperative assessment with lateral spine radiographs shows loss of lumbar lordosis. Spinopelvic mobility is reduced with change in sacral slope from sitting to standing less than 10 degrees conforming to the stiff pattern. Care should be taken to reduce acetabular component anteversion at THA in these fused hips, as the posterior pelvic tilt would increase the risk of posterior impingement and anterior dislocation. Fused hips require femoral neck osteotomy, true acetabular floor identification and restoration of the hip center with horizontal and vertical offset to achieve a good functional outcome. Cementless and cemented fixation have shown comparable long-term results with the choice dependent on bone stock at THA. Risks at THA in AS include intraoperative fractures, dislocation, heterotopic ossification, among others. There is significant improvement of functional scores and quality of life following THA in these deserving young individuals with fused hips and spine stiffness.

Mechanism of Hip Arthropathy in Ankylosing Spondylitis: Abnormal Myeloperoxidase and Phagosome

Background

The pathogenesis of Ankylosing spondylitis (AS) has not been elucidated, especially involving hip joint disease. The purpose of this study was to analyze the proteome of diseased hip in AS and to identify key protein biomarkers.

Material and Methods

We used label-free quantification combined with liquid chromatography mass spectrometry (LC–MS/MS) to screen for differentially expressed proteins in hip ligament samples between AS and No-AS groups. Key protein was screened by Bioinformatics methods. and verified by in vitro experiments.

Results

There were 3,755 identified proteins, of which 92.916% were quantified. A total of 193 DEPs (49 upregulated proteins and 144 downregulated proteins) were identified according to P < 0.01 and Log|FC| > 1. DEPs were mainly involved in cell compartment, including the vacuolar lumen, azurophil granule, primary lysosome, etc. The main KEGG pathway included Phagosome, Glycerophospholipid metabolism, Lysine degradation, Pentose phosphate pathway. Myeloperoxidase (MPO) was identified as a key protein involved in Phagosome pathway. The experiment of siRNA interfering with cells further confirmed that the upregulated MPO may promote the inflammatory response of fibroblasts.

Conclusions

The overexpression of MPO may contribute to the autoimmune inflammatory response of AS-affected hip joint through the phagosome pathway.

Prediction of Treatment Response According to ASAS-EULAR Management Recommendations in 1 Year for Hip Involvement in Axial Spondyloarthritis Based on MRI and Clinical Indicators

BACKGROUND

To predict the treatment response for axial spondyloarthritis (axSpA) with hip involvement in 1 year based on MRI and clinical indicators.

METHODS

A total of 77 axSpA patients with hip involvement (60 males; median age, 25 years; interquartile, 22-31 years old) were treated with a drug recommended by the Assessment of SpondyloArthritis international Society and the European League Against Rheumatism (ASAS-EULAR) management. They were prospectively enrolled according to Assessment in SpondyloArthritis international Society (ASAS) criteria. Clinical indicators, including age, gender, disease duration, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), were collected at baseline and in 3 months to 1-year follow-up. Treatment response was evaluated according to ASAS response criteria. MRI indicators consisting of bone marrow edema (BME) in acetabulum and femoral head, hip effusion, fat deposition, thickened synovium, bone erosion, bone proliferation, muscle involvement, enthesitis and bony ankylosis were assessed at baseline. Spearman's correlation analysis was utilized for indicator selection. The selected clinical and MRI indicators were integrated with previous clinical knowledge to develop multivariable logistic regression models. Receiver operator characteristic curve and area under the curve (AUC) were used to assess the performance of the constructed models.

RESULTS

The model combining MR indicators comprising hip effusion, BME in acetabulum and femoral head and clinical indicators consisting of disease duration, ESR and CRP yielded AUC values of 0.811 and 0.753 for the training and validation cohorts, respectively.

CONCLUSION

The model combining MRI and clinical indicators could predict treatment response for axSpA with hip involvement in 1 year.

Test-Retest Reliability and Validity of the Six Minute Stepper Test to Evaluate Functional Exercise Capacity in Patients with Ankylosing Spondylitis

OBJECTIVES

The 6-minute stepper test (6MST) is a submaximal test that requires little space to assess exercise capacity compared to the 6-minute walk test (6MWT). The study aims to investigate the test-retest reliability and convergent validity of 6MST and to compare physiological responses, dyspnea, fatigue perception with 6MST and 6MWT in patients with ankylosing spondylitis (AS).

METHODS

To test the convergent validity of 6MST, 65 patients performed both 6MWT and 6MST on the first day and correlation between two tests were assessed with Pearson correlation test. In order to investigate the test-retest reliability of the 6MST, thirty-two of the 65 patients performed 6MST one week later and intraclass correlation coefficients (ICC) were calculated. Dyspnea and fatigue perception were analyzed with using Wilcoxon signed-rank test, physiological responses were analyzed using paired sample t-test.

RESULTS

Excellent test-retest reliability was observed for 6MST (ICC: 0.988). There was a significant correlation between 6MST and 6MWT (r: 0.725, p<0.001). Dyspnea and leg fatigue perception were significantly higher in 6MST (p<0.05). Physiological responses and fatigue perception were similar in both 6MST and 6MWT (p>0.05).

CONCLUSION

This study demonstrated that the 6MST is reliable and valid method to evaluate exercise capacity in patients with AS. 6MST can be used to evaluate exercise capacity of patients with AS.

The Clinical and MRI Effect of TNF-α Inhibitors in Spondyloarthritis Patients With Hip Involvement: A Real-World Observational Clinical Study

Objectives

Hip involvement is an important cause of disability and poor prognosis in patients with spondyloarthritis (SpA). Tumor necrosis factor (TNF)-α inhibitor treatment has been demonstrated to be effective in SpA patients with hip arthritis; however, quantitative assessment using MRI in long-term follow-up needs further application and observation.

Methods

A total of 239 patients were involved in this study. Methotrexate and sulfasalazine were given as basic treatment. In total, 165 patients received TNF-α inhibitors plus basic treatment, and 74 received basic treatment only, as controls. Clinical symptoms were assessed at baseline and at weeks 12, 24, and 52. MRI performances of hip arthritis, including bone marrow edema (BME) and synovitis, were quantitatively assessed using the Hip Inflammation MRI Scoring System (HIMRISS).

Results

The clinical values of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Harris hip score, and Ankylosing Spondylitis Disease Activity Score (ASDAS)-ESR in both groups showed significant clinical remission at week 52 (p < 0.001). However, the change in disease activity levels at week 52 in the control group was significantly worse than in the TNF-α inhibitor group. At week 52, MRI showed a significant remission trend in the TNF-α inhibitor group versus baseline, and total HIMRISS scores were significantly decreased (26.49 ± 10.37 vs. 20.59 ± 9.41, p < 0.001); the control group only had slight improvement (p < 0.05).

Conclusions

TNF-α inhibitors could significantly improve clinical and MRI manifestations of hip involvement in patients with SpA. Quantitative MRI assessment combined with clinical assessment can be used to accurately evaluate the treatment effect of TNF-α in SpA patients with hip involvement to help guide targeted treatment.

Hip Replacement in Ankylosing Spondylitis Patients with Advanced Hip Involvement: Factors Associated with Bilateral Total Hip Arthroplasty

BACKGROUND

This study aimed to compare the clinical data of ankylosing spondylitis (AS) patients who underwent unilateral and bilateral total hip arthroplasty (THA) due to advanced hip involvement. Furthermore, to determine the factors associated with bilateral THA.

METHODS

Utilizing a single-institution database, we selected 373 consecutive AS patients undergoing primary THA from 2012 to 2017 and compared the clinical characteristics and anti-tumor necrosis factor (TNF) therapy of the patients who underwent unilateral and bilateral THA. Logistic regression was used to identify factors associated with bilateral THA.

RESULTS

Bilateral THA was performed in 67.3% (n=251) of the patients. Male patients had a higher frequency of undergoing bilateral THA compared with female ones (P<0.05). The proportion of the patients who had bilateral onset in hips, administration of TNF inhibitors, flexion contracture in the hip, and a BASRI-hip score of 4 was significantly higher in patients with bilateral THA than that with unilateral THA (P<0.05). Patients with bilateral THA experienced longer disease duration than those with unilateral THA (P<0.05). The results of the logistic regression showed that factors related to bilateral THA were bilateral onset in hips, administration of TNF inhibitors, a BASRI-hip score of 4, and an erythrocyte sedimentation rate (ESR) level (P<0.05).

CONCLUSION

Bilateral THA is more common in AS patients with advanced hip involvement. Bilateral onset in hips, a BASRI-hip score of 4, and a higher level of ESR are risk factors associated with bilateral THA, while anti-TNF therapy is a protective factor reducing the progression of hip involvement to bilateral THA.

MRI Assessment of Extra-axial Findings at Pelvic Sites in a Group of Axial-SpA Patients

Introduction

MRI allows a better evaluation of inflammatory and structural lesions of the sacroiliac joints and spine in patients with axial spondyloarthritis (axial SpA), so MRI plays an important role in the classification and diagnosis of axial SpA. The aim of our study was to assess extra-axial MRI findings at pelvic sites and their possible associations with clinical indices in patients with axial SpA.

Methods

Axial-SpA patients who were classified according to the ASAS criteria and consecutively attended our clinic were assessed with pelvic MRI. The main clinical and demographic characteristics of all patients, including age, sex, BMI, presence of HLA-B27 and type of axial SpA (radiographic or nonradiographic), were evaluated. The main indices of disease activity and joint function were assessed, including BASDAI, ASDAS-PCR, BASMI and BASFI. Finally, the presence/absence of inflammatory/structural lesions at extra-axial structures (the hip joints, pubic symphysis, greater and lesser trochanters, ischial tuberosity, iliac spines and iliac crest) was evaluated.

Results

35 patients (21 males and 14 females) with a mean age (SD) of 47 (12.7) years and a mean duration of symptoms of 5 (2.1) years were enrolled. Hip abnormalities were found in 14 (40%) patients. Trochanteric enthesopathy/bursitis and pubic osteitis were found in 2 patients (5.7%) and 1 patient (2.8%), respectively. No other abnormalities were found at other sites. We found significant associations between the presence of extra-axial alterations, disease activity and joint function.

Conclusions

Our study demonstrated the presence of extra-axial abnormalities in more than one-third of patients with axial SpA, suggesting that MRI evaluation should be extended to the entire pelvis.

Prevalence and distribution of peripheral musculoskeletal manifestations in spondyloarthritis including psoriatic arthritis: results of the worldwide, cross-sectional ASAS-PerSpA study

OBJECTIVES

To characterise peripheral musculoskeletal involvement in patients with spondyloarthritis (SpA) including psoriatic arthritis (PsA), across the world.

METHODS

Cross-sectional study with 24 participating countries. Patients with a diagnosis of axial SpA (axSpA), peripheral SpA (pSpA) or PsA according to their rheumatologist were included. The investigators were asked which diagnosis out of a list of six (axSpA, PsA, pSpA, inflammatory bowel disease-associated SpA, reactive arthritis or juvenile SpA (Juv-SpA)) fitted the patient best. Peripheral manifestations (ie, peripheral joint disease, enthesitis, dactylitis and root joint disease), their localisation and treatments were evaluated.

RESULTS

A total of 4465 patients were included (61% men, mean age 44.5 years) from four geographic areas: Latin America (n=538), Europe plus North America (n=1677), Asia (n=975) and the Middle East plus North Africa (n=1275). Of those, 78% had ever suffered from at least one peripheral musculoskeletal manifestation; 57% had peripheral joint disease, 44% had enthesitis and 15% had dactylitis. Latin American had far more often peripheral joint disease (80%) than patients from other areas. Patients with PsA had predominantly upper limb and small joint involvement (52%).Hip and shoulder involvement was found in 34% of patients. The prevalence of enthesitis ranged between 41% in patients with axSpA and 65% in patients with Juv-SpA. Dactylitis was most frequent among patients with PsA (37%).

CONCLUSION

These results suggest that all peripheral features can be found in all subtypes of SpA, and that differences are quantitative rather than qualitative. In a high proportion of patients, axial and peripheral manifestations coincided. These findings reconfirm SpA clinical subtypes are descendants of the same underlying disease, called SpA.

Assessment of hip involvement in patients with ankylosing spondylitis: reliability and validity of the Hip Inflammation MRI Scoring System

Background

This study aimed to test the reliability and validity of the Hip Inflammation MRI Scoring System (HIMRISS) in assessing hip involvement of AS patients with AS at different stages of the bath ankylosing spondylitis radiology index (BASRI-hip) scoring system.

Methods

Fifty-two outpatients with ankylosing spondylitis (AS) were included in this study. The subjects’ data includes demographics, clinical characteristics, disease activity score, and functional index. Based on the Harris hip scoring (HHS) of involved hip and BASRI-hip score, we devided these patients into no hip involvement group((HHS ≥ 80 and BASRI ≤ 1) (Group A), mild hip involvement subgroup (BASRI = 2 or BASRI ≤ 1 and HHS ≤ 79) (Group B), and moderate to advanced hip involvement subgroup (BASRI ≥ 3) (Group C). Data was analyzed statistically by SPSS software.

Results

In total of 44 patients (88 hips), group A consisted of 21 hips, group B consisted of 42 hips and group C consisted of 25 hips. The test–retest intraclass correlation coefficients (ICCs) in four raters were 0.955 ~ 0.977 and interrater ICC was 0.993. HIMRISS correlated moderately with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) (r = 0.540, p < 0.001), the Bath ankylosing spondylitis functional index (BASFI) (r = 0.540, p < 0.001), the Bath Ankylosing Spondylitis Functional Index (BASFI) (r = 0.581, p < 0.001), ASDAS-ESR (r = 0.604, p < 0.001), and Ankylosing Spondylitis Disease Activity Score (ASDAS)-C reactive protein (CRP) (r = 0.575, p < 0.001). HIMRISS in groups B and C was significantly higher than that in group A: 29.38 (17.00, 40.94) vs. 14.50 (11.38, 22.25), p = 0.009; 38 (31.13, 64.38) vs 14.50 (11.38, 22.25), p < 0.001.

Conclusions

HIMRISS applied to patients with AS demonstrated a satisfactory reliability, meaning it is a reliable quantitive assessment tool for evaluating early hip involvement in patients with AS.

Analysis of Bone Strength and Bone Turnover Markers in Ankylosing Spondylitis with Radiological Hip Involvement

Background

Limited clinical data are available on bone loss in ankylosing spondylitis (AS) patients with hip involvement, especially for bone strength. The purpose of this study was to analyze bone strength and bone turnover markers in AS patients with hip involvement.

Material/Methods

The stiffness index (SI) calculated by quantitative ultrasound (QUS) was used to compare the bone strength between patients with AS with radiographic hip involvement (RHI-AS, BASRI-hip ≥2) and those without radiographic hip involvement (WORHI-AS, BASRI-hip ≤1). The Spearman correlation test was used to evaluate the association between SI and bone turnover markers [TP1NP, OC, β-CTx, 25(OH)VD3, and PTH].

Results

RHI-AS (BASRI-hip ≥2) patients accounted for 52.2% (177/339) of all patients. There was no significant difference in most of the basic clinical features between RHI-AS and WORHI-AS patients, except for age and BMI. After adjusting for confounding factors (age and BMI), the stiffness index (SI) of RHI-AS patients was significantly lower than that of WORHI-AS patients (OR_adj=0.982, 95% CI_adj=0.968~0.997, P_adj=0.017). The Z scores calculated by SI were lower in RHI-AS patients (OR_adj=0.802, 95% CI_adj=0.679~0.949, P_adj=0.01). Among the 5 bone turnover markers in the RHI-AS patients, only 25(OH)VD3 had a correlation with SI (rho=0.279, P=0.001).

Conclusions

AS patients have lower bone strength once the disease progresses to include radiologic hip involvement. Treatment of vitamin D deficiency may be an effective way to improve bone strength in AS patients with hip involvement.

Root Joint Involvement in Spondyloarthritis: A Post-hoc Analysis from the International ASAS-PerSpA Study

OBJECTIVES

Primary objective was to compare the clinical characteristics of spondyloarthritis (SpA) patients with and without root joint disease (RJD+ and RJD-). Secondary objectives were to compare the prevalence of RJD across various SpA subtypes and in different world regions, to compare the SpA axial severity and SpA burden between RJD+ and RJD-.

METHODS

This is a post-hoc analysis of the ASAS-PerSpA study (PERipheral involvement in SpondyloArthritis), which included 4,465 patients with SpA (axial (axSpA), peripheral (pSpA), psoriatic (PsA), inflammatory bowel disease, reactive and juvenile) according to the rheumatologist's diagnosis. RJD was defined as the "ever" presence of hip or shoulder involvement related to SpA, according to the rheumatologist. The patient's characteristics were compared between RJD+ and RJD-. Multivariable stepwise binary logistic regression analyses were conducted to identify factors associated with "RJD", "hip" and "shoulder" involvement.

RESULTS

RJD was significantly associated with the SpA main diagnosis (highest in pSpA), a higher prevalence of HLA-B27 positivity, enthesitis, tender and swollen joints, CRP, cs-DMARDs, loss of lumbar lordosis and occiput-wall distance > 0. RJD was more prevalent in Asia, and occurred in 1,503 patients (33.7%), with more hip (24.2%) than shoulder (13.2%) involvement. Hip involvement had a distinct phenotype, similar to axSpA (including younger age at onset, HLA-B27 positivity), whereas shoulder involvement was associated with features of pSpA (including older age at onset).

CONCLUSION

RJD+ SpA patients had a distinctive clinical phenotype compared with RJD-. Hip involvement, based on the rheumatologist's diagnosis, was more prevalent than shoulder involvement and was clinically distinct.

A Comprehensive Assessment of Hip Damage in Ankylosing Spondylitis, Especially Early Features

Ankylosing spondylitis (AS) is most common in adolescents and the ultimate result is disability, which places a huge burden on patients and society. Therefore, the key to improve the prognosis of AS is the early diagnosis of hip injury. To examine if AS patients whose hip pain is either absent or minimal might already have observable MRI and X-ray hip changes. Clinical and imaging hip data were systematically analyzed in 200 healthy controls (HC) and 300 AS with varying degrees of hip pain. Forty-four patients with early hip osteoarthritis (OA) served as positive imaging controls. In MRI images, BME lesions in the STIR sequence were much more frequent in AS (62%) compared to HC (2%) (p < 0.0001). Most importantly, 42% of AS with no or minimal hip pain had one or more MRI lesions. This was much more frequent compared to the 2% in HC (p < 0.05). These lesions in AS were observed singly or in combination in the trochanters (8%), femoral heads (12%), and acetabula (13%). Parallel finding that X-ray changes were present in patients with minimal or no hip pain was also observed with X-ray. Based on the normal hip width of HC, joint space narrowing was observed in 94.3% of the entire AS cohort, and importantly 56.7% of AS patients with no or mild hip pain. In these latter patients, functional activities of the hips such as walking were normal. At least 40% of AS patients with minimal or no hip pain might already show MRI and X-ray changes.

Effects of types and degrees of ankylosing spondylitis hip structural damages on post-total hip arthroplasty outcome measurements

To determine the effects of ankylosing spondylitis (AS)-associated hip damages on the outcome measurements after total hip arthroplasty (THA).The medical records of 122 patients with AS (181 hips) who underwent THA were retrospectively reviewed. The mean follow-up was 43.9 (32-129) months. The types and degrees of hip damages were evaluated by preoperative hip X-rays. The patients were grouped according to the satisfaction degree after the operation. Univariable and multivariable statistical analyses were conducted.The intraclass correlation coefficients for the assessment between the 2 reviewers in the study were 0.86 to 0.97. Cox regression showed that femoral head erosion severity had an effect on the recovery time of independent walking without crutches postoperatively (odds ratio = 1.467, 95% confidence interval: 1.050-2.409, P = .025). The mean time to recover independent walking in the severe femoral head erosion group was 7.3 ± 0.9 weeks, which was 4.6 ± 0.4 weeks longer than in the non-severe femoral head erosion group, as confirmed by the log-rank (Mantel-Cox) test (Chi-squared = 11.684, P = .001). The multivariable analysis showed that higher acetabular sclerosis scores correlated with lower postoperative dissatisfaction risk (odds ratio = 0.322, 95% confidence interval: 0.136-0.764). The multiple linear regression analysis showed that postoperative range of motion (ROM) improvement was affected by preoperative ROM of the hip, space narrowing degree, and ceramic-ceramic material for the weight-bearing surface (F = 179.81, P < .001), with preoperative ROM of the hip having the greatest impact.Severe femoral head erosion prolongs the recovery time of independent walking after THA. Acetabular sclerosis is not associated with poor outcomes in patients with AS-associated hip damage undergoing THA.

Efficacy of needle-knife combined with etanercept treatment regarding disease activity and hip joint function in ankylosing spondylitis patients with hip joint involvement: A randomized controlled study

This study aimed to assess the efficacy of needle-knife (NK) combined with etanercept (NKCE) in attenuating pain, inflammation, disease activity, and improving hip joint function in ankylosing spondylitis (AS) patients with hip joint involvement.Totally, 90 patients with active AS involving unilateral hip joint were enrolled and randomly assigned in 1:1:1 ratio to receive NKCE, NK or conventional drugs (control). The ESR, CRP, hip joint pain Visual Analogue Scale (VAS) score, bath ankylosing spondylitis disease activity index (BASDAI), bath ankylosing spondylitis functional index (BASFI), modified Harris hip score (mHHS), and range of motion (ROM) of affected hip joint were assessed at baseline (W0), after 1-week treatment (W1) and after 24-week treatment (W24).ESR and CRP were decreased in NKCE group compared with NK and control groups, while was not attenuated in NK group compared with control group. Regrading pain and disease activity, NKCE group presented a reduction in hip pain VAS score and BASDAI compared with NK and control groups, and NK group showed a decrease in hip pain VAS score and BASDAI compared with control group. Besides, BASFI was lowered in NKCE and NK groups compared with control group, but similar between NKCE and NK groups. mHHS and hip ROM were raised in NKCE and NK groups compared with control group, but similar between NKCE and NK groups.NKCE decreases hip pain, inflammation, disease activity and improves hip joint function in AS patients with hip joint involvement.

Cross-sectional study of patients with axial spondyloarthritis fulfilling imaging arm of ASAS classification criteria: baseline clinical characteristics and subset differences in a single-centre cohort

OBJECTIVE

This study compared demographic, clinical and laboratory characteristics between patients with radiographic and non-radiographic axial spondyloarthritis (axSpA).

METHODS

In this single-centre cross-sectional study, a total of 246 patients with axSpA fulfilling the imaging arm of Assessment of SpondyloArthritis International Society classification criteria were recruited. A total of 140 patients were diagnosed as non-radiographic axial spondyloarthritis (nr-axSpA), and 106 patients had ankylosing spondylitis (AS). Sociodemographic characteristics, disease manifestations, clinical and laboratory disease activity and their differences between subsets were analysed. P values below 0.05 with CI 95% were considered statistically significant.

RESULTS

More nr-axSpA patients were women (61.4%) compared with 24.7% of AS patients. First symptoms developed earlier in AS patients compared with nr-axSpA (23.0 (IQR 17.5-30.0) vs 27.8 (IQR 21.0-33.7) years, p=0.001). Disease manifestations did not differ, but patients with nr-axSpA experienced peripheral arthritis more frequently (35.7% vs 17.0%, p=0.001) with less hip involvement (8.6% vs 18.9%, p=0.022) compared with patients with AS. Patients with AS exhibited worse spinal mobility and physical function compared with nr-axSpA. AS Disease Activity Scores and CRP levels were significantly higher in patients with AS compared with nr-axSpA (2.4 (IQR 1.7-2.8) vs 2.0 (IQR 1.1-2.3), p=0.022 and 7.1 (IQR 2.6-14.9) vs 2.5 (IQR 0.8-8.2) mg/L, p<0.001, respectively).

CONCLUSIONS

Our data demonstrated some known and also novel differences between the two imaging arm fulfilling axSpA subgroups. Non-radiographic patients were mostly women who had experienced shorter disease duration, milder disease activity and better functional status with less hip involvement but more peripheral arthritis compared with patients with AS.

Rhoifolin ameliorates titanium particle-stimulated osteolysis and attenuates osteoclastogenesis via RANKL-induced NF-κB and MAPK pathways

Prosthesis loosening is a highly troublesome clinical problem following total joint arthroplasty. Wear-particle-induced osteoclastogenesis has been shown to be the primary cause of periprosthetic osteolysis that eventually leads to aseptic prosthesis loosening. Therefore, inhibiting osteoclastogenesis is a promising strategy to control periprosthetic osteolysis. The possible mechanism of action of rhoifolin on osteoclastogenesis and titanium particle-induced calvarial osteolysis was examined in this study. The in vitro study showed that rhoifolin could strongly suppress the receptor activators of nuclear factor-κB (NF-κB) ligand-stimulated osteoclastogenesis, hydroxyapatite resorption, F-actin formation, and the gene expression of osteoclast-related genes. Western blot analysis illustrated that rhoifolin could attenuate the NF-κB and mitogen-activated protein kinase pathways, and the expression of transcriptional factors nuclear factor of activated T cells 1 (NFATc1) and c-Fos. Further studies indicated that rhoifolin inhibited p65 translocation to the nucleus and the activity of NFATc1 and NF-κB rhoifolin could decrease the number of tartrate-resistant acid phosphate-positive osteoclasts and titanium particle-induced C57 mouse calvarial bone loss in vivo. In conclusion, our results suggest that rhoifolin can ameliorate the osteoclasts-stimulated osteolysis, and may be a potential agent for the treatment of prosthesis loosening.

Inhibition of CXCR4 inhibits the proliferation and osteogenic potential of fibroblasts from ankylosing spondylitis via the Wnt/β‑catenin pathway

Ankylosing spondylitis (AS) is an autoimmune condition characterized by chronic inflammation and abnormal ossification as the primary features of the disease. The aim of the present study was to investigate the role of C‑X‑C chemokine receptor type 4 (CXCR4) in ossification from patients with AS. CXCR4 expression was assessed by western blot analysis and immunohistochemistry analysis of tissues obtained from patients with AS and controls. Fibroblasts were isolated, cultured and incubated with AMD 3100 and stromal cell‑derived factor‑1 to inhibit and promote CXCR4 levels, respectively. CXCR4 was upregulated in hip synovial tissues from patients with AS compared with that observed in controls. AS fibroblasts exhibited increased proliferation and growth rates. Inhibition of CXCR4 increased the phosphorylation of β‑catenin and downregulated the expression of β‑catenin, v‑myc avian myelocytomatosis viral oncogene homolog, cyclin D1 and osteocalcin. Alizarin red staining demonstrated a decrease in biomineralization activity following the inhibition of CXCR4. These data support the hypothesis that inhibiting CXCR4 in patients with AS may suppress the ossification of fibroblasts.

Clinical and MRI response to dose reduction of an etanercept-biosimilar for hip arthritis in patients with ankylosing spondylitis: an observational, retrospective cohort study

OBJECTIVES

Hip arthritis plays a critical role in the prognosis of ankylosing spondylitis (AS). Dose reduction of tumor necrosis factor inhibitors preserves general improvement of AS, so this study attempted to examine the equivalence between Yisaipu® tapering and conventional therapy for hip arthritis in AS patients, using clinical parameters and magnetic resonance image (MRI).

METHODS

AS patients received this etanercept-biosimilar injections (50 mg/week) in the first 12 weeks. Participants in the tapering group were treated with this reagent 50 mg every other week from week 13 to week 24, while the control group kept undergoing full-dose therapy. Clinical and laboratory parameters were assessed at baseline, week 12 and week 24. MRI examination of hip was performed at baseline and week 24.

RESULTS

One hundred and thirty-six patients were enrolled, and 80 of them were in the tapering group. Linear mixed model revealed that main effects of tapering group with control group as reference in disease activity parameters were insignificant (p > 0.05). Main effects of baseline with week 24 as reference were significant (p < 0.05), but main effects of week 12 with week 24 as reference were not (p > 0.05). Prevalence of acute inflammatory change in MRI significantly decreased in the tapering group (76.88% vs 20.00%, p < 0.05) and control group (76.79% vs 19.64%, p < 0.05). Influence of both treatments on acute inflammatory change was equivalent (p > 0.05).

CONCLUSION

Efficacy of Yisaipu® tapering treatment is comparable to the full-dose therapy for hip arthritis in AS patients. Both treatments maintain remission of hip arthritis after patients achieved low disease activity.

Causes of Chronic Hip Pain Undiagnosed or Misdiagnosed by Primary Physicians in Young Adult Patients: a Retrospective Descriptive Study

BACKGROUND

Hip pain is a common musculoskeletal complaint in general practice. Although comprehensive diagnostic approach on hip pain is mandatory for adequate treatment, un- or mis-diagnosis is not rare in primary care. The aim of this study was to analyze descriptively un- or mis-diagnosed hip pain cases referred from primary care to a tertiary hospital, especially in young adults ≤ 50 years old.

METHODS

We retrospectively analyzed a consecutive cohort of 150 patients (≤ 50 years old) with chronic hip pain (≥ 6 weeks), which was not diagnosed or misdiagnosed based on the information provided on the referral form.

RESULTS

Overall an average 32 cases/month were referred due to hip pain without a diagnosis or with an incorrect diagnosis. Among them, 150 patients were enrolled in this study and 146 (97.3%) could be allocated to a specific disease by using data from routine clinical practice. Four common final diagnoses were femoroacetabular impingement (FAI) syndrome (55.3%), hip dysplasia (HD, 13.3%), referred pain from the lumbar spine (9.3%), and spondyloarthritis (SpA, 7.3%). In patients with FAI syndrome, 37 (44.0%) had pincer-type FAI and 33 (39.8%) had combined-type. Although the pain site or gender was not tightly clustered, the distribution of final diagnosis was significantly different according to hip pain location or gender. Especially, SpA or HD was not observed in younger women subgroup or elder men subgroup, respectively, when stratified by the mean age of participants.

CONCLUSION

Most (> 80%) young patients with hip pain, a difficult issue to diagnosis for many primary physicians, had FAI syndrome, HD, spine lesions, and SpA. This study could give a chance to feedback information about cases with un- or mis-diagnosed hip pain, and it suggests that primary physicians need to be familiar with the diagnostic approach for these 4 diseases.

Application and preliminary validation of the hip inflammation MRI scoring system (HIMRISS) in spondyloarthritis

AIMS

Spondyloarthritis (SpA) is an inflammatory rheumatic disease and hip involvement often results in severe deformities and functional impairment. Magnetic resonance imaging (MRI) is a powerful imaging tool for detecting early hip lesions in SpA. The aims of this study are to apply the hip inflammation MRI scoring system (HIMRISS) in SpA patients and to evaluate its reproducibility and validity.

METHODS

Four readers new to HIMRISS (two radiologists and two rheumatologists) scored the MRI scans obtained from a total of 55 SpA patients with hip lesions in two separate exercises (33 patients in exercise 1 and 22 patients in exercise 2). After the training and review process for exercise 1, these well-trained readers with expertise in the HIMRISS method scored the scans obtained from 22 patients and evaluated the association between HIMRISS and clinical activity of SpA, including Ankylosing Spondylitis Disease Activity Score (ASDAS), laboratory features, Bath Ankylosing Spondylitis Disease Activity Index and Harris hip scores.

RESULTS

HIMRISS is a reliable MRI scoring method for bone merrow lesions (BML) and synovitis in SpA. After 2 training exercises, the reliability improved from 0.67 to 0.90. The reliability for detecting femoral BML, acetabular BML, and synovitis effusion was very good after the 2 exercises (overall intraclass correlation coefficient = 0.73, 0.84 and 0.88, respectively). The clinical correlations between HIMRISS and ASDAS were most significant, and the correlations were closer to summed bilateral HIMRISS scores than just the worse side. HIMRISS was found to be an excellent tool for the early diagnosis of inflammation before the occurrence of structural damage, which was not significantly reflected in the systemic diagnosis.

CONCLUSION

HIMRISS offers a reliable MRI scoring method for hip joint in SpA, and it is beneficial for early detection and fast quantification in disease activity assessment.

Radiographic progression in non-radiographic axial spondyloarthritis

INTRODUCTION

Non-radiographic axial spondyloarthritis (nr-axSpA) represents a subtype of axial spondyloarthritis (axSpA) with no significant structural damage in sacroiliac joints and spine. In addition, patients with nr-axSpA demonstrate a substantial burden of illness, and a considerable share of them might progress to radiographic axSpA (r-axSpA) over time. The amount and quality of published data allows crude estimation of progression rate and factors related to a higher risk of progression. Areas covered: This review discusses the available data reporting the rates and predictors of radiographic progression in the sacroiliac joints and in the spine in patients with nr-axSpA as well as predisposing factors for such a progression. Expert commentary: Most of the studies report about 10-40% of patients with nr-axSpA to progress to r-axSpA over a period of 2-10 years. Multiple risk factors for the radiographic sacroiliitis progression are outlined and explored. There are not enough data to presume that any treatment modality may influence progression from nr-axSpA to r-axSpA, with TNFi showing some promising results. Radiographic progression in the spine is in general low in nr-axSpA; thus, long-term studies are required to investigate the natural course of the progression and possible treatment effects.