Correlation between mobility restrictions and radiologic changes in ankylosing spondylitis

Schober test is not a valid assessment tool for lumbar mobility

The Schober test is considered reliable in evaluating lumbar mobility and its impairment. Especially in patients with chronic low back pain (cLBP) identification of functional restriction is important. We aimed to investigate whether the 5 cm Schober cut-off provides a valid distinction between unrestricted and restricted mobility in participants with and without cLBP (18-65 years). cLBP is defined as LBP persisting for ≥ 12 weeks. We analyzed agreement between the Schober test with two measurement devices (Epionics SPINE®; Idiag M360®) and the influence of lumbar lordosis (LL) on their agreement. Also, the sensitivity and specificity of the Schober test was evaluated. For 187 participants (49.6%) Epionics SPINE® RoF and Schober test matched (either ≥ 5 cm; > 40.8° RoF or ≤ 5 cm; < 40.8° RoF), for 190 participants (50.4%) the two measurements did not. Idiag M360® RoF of 190 participants (50.4%) showed corresponding results (either ≥ 5 cm; > 46.0° RoF or ≤ 5 cm; < 46.0° RoF). Non-agreement was seen in 187 participants (49.6%). LL differed significantly in the Epionics SPINE® cohort (p < 0.001). Regarding the Epionics SPINE® cohort, Schober test showed a sensitivity of 79.6% with a specificity of 36.1%. For the Idiag M360® cohort, Schober test showed a sensitivity of 68.2% and a specificity of 46.6%. Our results do not establish a consistent matching between Schober test and the device measurements. Therefore, Schober test may not be valid to predict impairment of lumbar mobility. We recommend Schober test as an add-on in monitoring of an individual relative to its case.

Which Metrological Index-the BASMI or EDASMI-is Best Correlated With Disease-Related Parameters in Spondylarthritis Patients?

OBJECTIVE

To compare the Edmonton Ankylosing Spondylitis Metrology Index (EDASMI) and Bath Ankylosing Spondylitis Metrology Index (BASMI) to determine which of the two is best correlated with disease-related parameters in axial spondyloarthritis (axSpA) patients.

METHODS

A cross-sectional study was made of 86 patients with radiographic axSpA. Sociodemographic data, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Ankylosing Spondylitis Disease Activity Score (ASDAS), the Bath Ankylosing Spondylitis Functional Index (BASFI), and the Ankylosing Spondylitis Quality of Life (ASQoL) questionnaire were applied. Spinal mobility was assessed by two indices: the BASMI and the EDASMI. Structural damage of the spine was also evaluated by two indices: the Bath Ankylosing Spondylitis Radiology Index (BASRI) and the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS).

RESULTS

Eighty-six patients with an average age of 43.21 ± 11.43 years (20-79) were included. Impaired spinal mobility, which corresponds to higher BASMI scores, was correlated with prolonged disease duration (p < 0.01, r = 0.310), higher ASDAS-CRP (p < 0.001, r = 0.386), severe functional disability on the BASFI (p < 0.01, r = 0.505) and poorer quality of life according to the ASQoL (p < 0.01, r = 0.369). However, the EDASMI score did not correlate with any disease parameter. The BASMI was correlated with the total BASRI (p < 0.01, r = 0.634) and mSASSS (p < 0.01, r = 0.388). Unlike the BASMI, the EDASMI was neither correlated with the BASRI (p = 0.520, r = 0.245) nor the mSASSS (p = 0.252, r = -0.120).

CONCLUSION

Our results indicate that among the studied metrological indices, the BASMI is more contributory since it is correlated with clinical disease parameters and structural damage, unlike the EDASMI.

Repeated Spinal Mobility Measures and Their Association With Radiographic Damage in Ankylosing Spondylitis

Objective

We sought to explore the relationship between changes in repeated mobility measures and spinal structural progression in patients with ankylosing spondylitis (AS) over time.

Methods

We studied patients with AS from the PSOAS (Prospective Study of Outcomes in AS) cohort and performed longitudinal multivariable regression modeling to assess the relationship of structural damage measured by their regional (cervical or lumbar) modified Stoke AS Spinal Score(mSASSS) and selected cervical (eg, cervical rotation, lateral bending, and occiput‐to‐wall distance) and lumbar spinal mobility measures (eg, Schöber’s test and lumbar lateral bending) that were collected at least every 2 years from 2003 to 2019.

Results

The median length of follow‐up for our 518 patients with cervical mSASSS measurements and 573 with lumbar mSASSS measurements was 4.08 (interquartile range [IQR] 2.25‐6.67) and 4.17 (IQR 2.25‐6.67) years, respectively. Among the mobility measures, based on multivariable regression models adjusting for clinical/demographic variables and C‐reactive protein, we did not observe meaningful associations between changes in spinal mobility with their respective regional mSASSS. Baseline mSASSS, male sex, increased C‐reactive protein (CRP), and longer disease duration were associated with increased longitudinal mSASSS in all analyses.

Conclusion

Our study shows that 2‐year changes in individual spinal mobility measures are not reliably associated with increased, longitudinal, AS‐related spinal structural progression. We also confirmed the relationship of baseline mSASSS, sex, CRP, and disease duration with AS‐related structural spinal progression over time.

Axial Disease in Psoriatic arthritis: The presence and progression of unilateral grade 2 sacroiliitis in a psoriatic arthritis cohort

BACKGROUND/PURPOSE

A universally accepted definition of axial psoriatic arthritis (axPsA) is lacking. We aimed to 1) assess the presence of axial involvement as defined by "at least unilateral grade 2 sacroiliitis (Uni2SI)" and 2) assess the radiographic progression of Uni2SI and identify risk factors for progression.

METHODS

PsA patients participating in a prospective observational cohort were classified according to their highest sacroiliitis grade. The baseline features of patients with Uni2SI were compared to patients meeting the radiographic criteria of the modified New York Ankylosing Spondylitis (mNY AS) criteria. Risk factors were examined for progression from Uni2SI in a sub-group of patients with >1 follow-up radiographs. Logistic regression and a survival analysis were carried out and identified risk factors associated with radiographic mNY AS compared to Uni2SI.

RESULTS

Axial disease defined as ≥Uni2SI was detected in 612/1354 patients (45%). mNY AS sacroiliitis was observed in 477 patients (35%). Radiographic progression of Uni2SI was assessed in 154 patients, 80 (52%) progressed to mNY AS criteria within 5.5 years. At baseline, progressors were diagnosed at a younger age (35.6 vs. 38.9, p = 0.05), had less degenerative disc disease (OR = 0.47, p = 0.02), worse peripheral radiographic damage (OR=1.02, p = 0.03) and worse psoriasis (OR = 1.09, p = 0.01) compared to non-progressors. Patients with an elevated erythrocyte sedimentation rate were more likely to progress (HR = 1.83, p = 0.02), while patients with longer disease duration were less likely to progress (HR = 0.95, p = 0.02).

CONCLUSION

The radiographic mNY AS criteria appear to be suitable for defining axial PsA according to radiographs. MRI definitions are needed as well for the most appropriate definition of axial PsA.

Is axial psoriatic arthritis distinct from ankylosing spondylitis with and without concomitant psoriasis?

OBJECTIVE

The aim of this study was to compare patients with ankylosing spondylitis with psoriasis (ASP) and without psoriasis (AS), to axial PsA (axPsA) patients.

METHODS

Two adult cohorts were recruited from the AS clinic: ASP and AS. These two cohorts were compared with two adult cohorts recruited from the PsA clinic: axPsA (radiographic sacroiliitis: ⩾bilateral grade 2 or unilateral grade 3 or 4); and Peripheral PsA. All patients were followed prospectively according to the same protocol. The demographic, clinical and radiographic variables were compared. Adjusted means were used to account for varying intervals between visits. A logistic regression was performed and adjusted for follow-up duration.

RESULTS

There were 477 axPsA patients, 826 peripheral PsA, 675 AS and 91 ASP patients included. AS patients were younger (P < 0.001), more male and HLA-B*27 positive (76%, 72% vs 64%, P ⩽ 0.001, 82%, 75%, vs 19%, P = 0.001). They had more back pain at presentation (90%, 92% vs 19%, P = 0.001), worse axial disease activity scores (bath ankylosing spondylitis disease activity index: 4.1, 3.9 vs 3.5 P = 0.017), worse back metrology (bath ankylosing spondylitis metrology index: 2.9, 2.2 vs 1.8, P < 0.001), worse physician global assessments (2.4, 2.2 vs 2.1, P < 0.001), were treated more with biologics (29%, 21% vs 7%, P = 0.001) and had a higher grade of sacroiliitis (90%, 84% vs 51%, P < 0.001). Similar differences were detected in the comparison of ASP to axPsA and in a regression model.

CONCLUSION

AS patients, with or without psoriasis, seem to be different demographically, genetically, clinically and radiographically from axPsA patients. axPsA seems to be a distinct entity.

Modified stoke ankylosing spondylitis spinal score as an outcome measure to assess the impact of treatment on structural progression in ankylosing spondylitis

In ankylosing spondylitis (AS), structural damage that occurs as a result of syndesmophyte formation and ankylosis of the vertebral column is irreversible. Structural damage is currently assessed by conventional radiography and scoring systems that reliably assess radiographic structural damage are needed to capture the differential effects of drugs on structural damage progression. The validity of the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) as a primary outcome measure in evaluating the effect of AS treatments on radiographic progression rates was assessed in this review. The mSASSS has not been used, to date, as a primary outcome measure in a prospective randomized controlled clinical trial of biologic therapy in AS. This review of the medical literature confirmed that the mSASSS is the most validated and widely used method for assessing radiographic progression in AS, correlating with worsening measures of disease signs and symptoms, spinal mobility and physical function, with a 2-year interval being required to ensure sufficient sensitivity to change.

Disease Activity and Patient-Reported Health Measures in Relation to Cytokine Levels in Ankylosing Spondylitis

INTRODUCTION

Ankylosing spondylitis (AS) is a lifelong condition where spinal inflammation causes chronic back pain and restriction of spinal function. While proinflammatory cytokines participate in the disease process, their relation with disease activity, spinal function, and quality of life is less well understood.

METHODS

Cross-sectional study of serum levels of four inflammatory cytokines (IL-6, TNF, IL-23, and IL-17A) in AS patients not on biologics. Disease characteristics and simultaneous spinal function tests and patient-reported health measures (Bath Functional Index (BASFI), Dougados Functional Index (DFI), Modified Health Assessment Questionnaire (MHAQ), and routine laboratory parameters were recorded. The composite ASDAS-CRP score was used to classify disease activity as absent, low, or high.

RESULTS

In 164 AS patients (age 46 years, 70.1% males, 90.9% HLAB27 positive, ASDAS-CRP 1.8), disease activity was classified as inactive in 14%, low in 54%, and high in 31%. ASDAS-CRP correlated well with MHAQ, DFI, BASFI, and spinal mobility across patients with low and high disease activity (all p < 0.05). Cytokine levels did not correlate with ASDAS-CRP, ESR, BASFI, or spinal mobility scores and were comparable between patients with no, low, or high disease activity regardless of gender or disease duration (all p > 0.2).

CONCLUSIONS

A large proportion of AS not on biologics have active disease far into the disease course. This impacts negatively on quality of life, work ability, and spinal mobility. Serum cytokine levels are poor markers for these central disease features in AS management.

FUNDING

Abbott Norway AS and Arthritis Foundation of Western Australia.

Can ultrasound be an assessment tool for sagittal spine mobility and chest expansion in patients with ankylosing spondylitis?

We aimed to examine whether ultrasound (US) is useful for evaluating spinal mobility and chest expansion in ankylosing spondylitis (AS) patients and determine a cutoff value to identify reduced sagittal lumbar mobility.Our cross-sectional study included 50 AS patients and 50 controls. Metric measurements and Bath AS indices were measured in AS patients. The distance between C6-C7, T11-T12, and L4-L5 vertebrae was measured, and the difference and percentage of difference between erect position and maximal cervical and lumbar flexion was calculated (T11-T12dif, T11-T12%, L4-L5dif, L4-L5%, T+L dif, T+L%). Intercostal divergence was measured 1.5 cm away on the left from the sternocostal space during maximum inhalation and maximum exhalation, and the difference and percentage of difference between them was calculated (ICdif, IC%).All metric measurements were lower in the AS group except for tragus-to-wall distance. T11-T12dif, T11-T12%, L4-L5dif, T+L dif, and T+L% values were higher in the control group, while other US measurements did not differ between the groups. All US measurements except ICdif and IC% correlated with the Bath AS Metrology Index.Thus, US may be used for assessing spinal mobility in patients with AS. T11-T12dif <0.79 cm may show decreased lumbar sagittal mobility.

Relevance of structural damage in the sacroiliac joints for the functional status and spinal mobility in patients with axial spondyloarthritis: results from the German Spondyloarthritis Inception Cohort

Background

Functional status and spinal mobility in patients with axial spondyloarthritis (axSpA) are known to be determined both by disease activity and by structural damage in the spine. The impact of structural damage in the sacroiliac joints (SIJ) on physical function and spinal mobility in axSpA has not been studied so far. The objective of the study was to analyze the impact of radiographic sacroiliitis on functional status and spinal mobility in patients with axSpA.

Methods

In total, 210 patients with axSpA were included in the analysis. Radiographs of SIJ obtained at baseline and after 2 years of follow up were scored by two trained readers according to the modified New York criteria grading system (grade 0–4). The mean of two readers’ scores for each joint and a sum score for both SIJ were calculated for each patient giving a sacroiliitis sum score between 0 and 8. The Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI) at baseline and after 2 years were used as outcome measures.

Results

Longitudinal mixed model analysis adjusted for structural damage in the spine (modified Stoke Ankylosing Spondylitis Spine Score - mSASSS), disease activity (Bath Ankylosing Spondylitis Disease Activity Index - BASDAI and C-reactive protein level) and gender, revealed an independent association of the sacroiliitis sum score with the BASFI: b = 0.10 (95% CI 0.01–0.19) and the BASMI: b = 0.12 (95% CI 0.03–0.21), respectively, indicating that change by one radiographic sacroiliitis grade in one joint is associated with BASFI/BASMI worsening by 0.10/0.12 points, respectively, independently of disease activity and structural damage in the spine.

Conclusion

Structural damage in the SIJ might have an impact on functional status and spinal mobility in axSpA independently of spinal structural damage and disease activity.

Trial registration

ClinicalTrials.gov, NCT01277419. Registered on 14 January 2011.

Inter-rater reliability of clinical mobility measures in ankylosing spondylitis

BACKGROUND

Several measurements are often used in daily clinical practice in the assessment of Ankylosing Spondylitis (AS) patients. The Assessment in SpondyloArthiritis International Society (ASAS) recommend in its core set: chest expansion modified Schöber test, Occiput to wall distance, lateral lumbar flexion, cervical rotation and The Bath Ankylosing Spondylitis Metrology Index (BASMI). BASMI also includes five measurements, some of them recommended by ASAS. Three versions of BASMI have been published with different scales and intervals for each component of the index. Though studies about reliability of these measurements are needed. The aim of this study was to analyze inter-rater reliability of recommended spinal mobility measures in AS.

METHODS

We examined reproducibility of spinal mobility measurements on 33 AS patients performed by two experienced rheumatologists in the same day. Descriptive statistics, Intraclass Correlation Coefficients (ICC), and Smallest Detectable Difference (SDD) using the Bland-Altman criteria were obtained for all the measurements.

RESULTS

Chest expansion showed the lowest value of ICC (0.66) and occiput-wall the highest (0.97). SDD was 2.43 units for BASMI2 and 1.27 units for BASMI10.

CONCLUSIONS

Reliability according to ICC was moderate to high in all measurements. BASMI10, instead BASMI2, must be used: measurements used to calculate are the same but there is better reliability. Inter-rater variation, expressed as SDD, must be taken in account: smaller improvements do not demonstrate the efficacy of treatment because they can be due to experimental error and not to the treatment itself.

Criterion-concurrent Validity of Spinal Mobility Tests in Ankylosing Spondylitis: A Systematic Review of the Literature

Objective.

To examine the level of evidence for criterion-concurrent validity of spinal mobility assessments in patients with ankylosing spondylitis (AS).

Methods.

Guidelines proposed in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses were used to undertake a search strategy involving 3 sets of keywords: accura*, truth, valid*; ankylosing spondylitis, spondyloarthritis, spondyloarthropathy, spondylarthritis; mobility, spinal measure*, (a further 16 keywords with similar meaning were used). Seven databases were searched from their inception to February 2014: AMED, Embase, ProQuest, PubMed, Science Direct, Scopus, and Web of Science. The Quality Assessment of Diagnostic Accuracy Studies (with modifications) was used to assess the quality of articles reviewed. An article was considered high quality when it received “yes” in at least 9 of the 13 items.

Results.

From the 741 records initially identified, 10 articles were retained for our systematic review. Only 1 article was classified as high quality, and this article suggests that 3 variants of the Schober test (original, modified, and modified-modified) poorly reflect lumbar range of motion where radiographs were used as the reference standard.

Conclusion.

The level of evidence considering criterion-concurrent validity of clinical tests used to assess spinal mobility in patients with AS is low. Clinicians should be aware that current practice when measuring spinal mobility in AS may not accurately reflect true spinal mobility.

Frequency of fragmented QRS in ankylosing spondylitis : a prospective controlled study

OBJECTIVES

Since inflammatory diseases may also cause fibrosis, we hypothesized that patients with ankylosing spondylitis (AS) may have frequent fragmented QRS complexes (fQRS) when compared to a control group.

PATIENTS AND METHODS

In this prospective study, 71 patients with AS (group 1) were compared with 42 age- and gender-matched individuals without rheumatic disease (group 2, control). fQRS was described as the presence of an additional R wave (R') or R or S wave bridging, or the presence of fragmentation on two consecutive derivations that correspond to the major coronary artery regions.

RESULTS

The mean ages of groups 1 and 2 were 37.67 ± 9.17 and 40.43 ± 11.09 years, respectively (p = 0.270). fQRS was detected in 23 AS patients (32.4%), whereas 3 patients in the control group had fQRS (7.14%). Age, gender, medication, and echocardiography results were comparable. The disease duration score was 101.37 ± 59.96 months in fQRS(+) patients; in contrast, it was 57.93 ± 30.95 months in fQRS(-) patients. This difference was of statistical significance (p = 0.046). A statistically significant difference was not determined between the fQRS(+) and fQRS(-) groups when evaluated in terms of HLAB27 (p = 0.739). In the fQRS(+) group, the mean lumbar Schober score was 2.91 ± 1.52; in patients without fQRS, it was 4.10 ± 1.40. The mean thoracic expansion test scores in the fQRS(+) and fQRS(-) groups were 1.44 ± 0.66 and 2.69 ± 1.22, respectively.

CONCLUSION

Given the higher frequency of fQRS detected in electrocardiography studies in AS patients than in the control group, cardiac fibrosis is thought to be more likely to occur in AS patients without cardiovascular disease. The presence of fQRS may be a simple and cost-effective method for predicting cardiac fibrosis in AS patients. fQRS can be a predictive marker for fibrosis in patients with AS.

Spinal mobility, vertebral squaring, pulmonary function, pain, fatigue, and quality of life in patients with ankylosing spondylitis

OBJECTIVE

To investigate the relationships between spinal mobility, pulmonary function, structural change of the spine, pain, fatigue, and quality of life (QOL) in patients with ankylosing spondylitis (AS).

METHODS

Thirty-six patients with AS were recruited. Their spinal mobility was examined through seven physical tests: modified Schober test, lateral bending, chest expansion, occiput to wall, finger to ground, bimalleolar distance, and range of motion (ROM) of the spine. Pulmonary Function Test (PFT) was performed using a spirometer, and vertebral squaring was evaluated through the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). QOL, disease activity, functional capacity, and fatigue were evaluated by SF-36 Health Survey (SF-36), the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), and the Multidimensional Assessment of Fatigue (MAF) scale, respectively. Perceived physical condition and degree of pain were assessed using 10 cm visual analogue scale.

RESULTS

Participants showed reduced spinal mobility, which was negatively correlated with mSASSS. PFT results showed reduced forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) and increased FEV1/FVC. Reduced FEV1 and FVC showed positive correlations with reduced spinal mobility and a negative relationship with mSASSS. Perceived physical condition and degree of pain were both significantly related to the SF-36, BASDAI, BASFI, and MAF scores.

CONCLUSION

This study shows that both reduced spinal mobility and radiographic changes in the vertebral body may have a predictive value for pulmonary impairment in patients with AS. Likewise, pain and perceived physical condition may play an important role in the QOL, functional capacity, and fatigue level of these patients.

Regional radiographic damage and functional limitations in patients with ankylosing spondylitis: differences in early and late disease

OBJECTIVE

Both radiographic damage and functional limitations increase with the duration of ankylosing spondylitis (AS). We examined whether radiographic damage contributed more to functional limitations in late AS than in early AS, and if the strength of association varied with the anatomic region of damage.

METHODS

In this cross-sectional study of 801 patients with AS, we examined associations of the lumbar modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), the cervical mSASSS, lumbar posterior fusion, cervical posterior fusion, and hip arthritis with the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Health Assessment Questionnaire modified for the spondyloarthritides (HAQ-S).

RESULTS

Higher lumbar and cervical mSASSS scores were associated with more functional limitations, but there was an interaction between mSASSS scores and the duration of AS, such that the strength of their association with functional limitations decreased with increasing duration of AS. Cervical posterior fusion was associated with worse functioning independent of mSASSS scores. Hip arthritis was significantly associated with functional limitations independent of spinal damage measures. Among patients with AS duration ≥40 years, the number of comorbid conditions accounted for most of the variation in functioning. Results were similar for both the BASFI and the HAQ-S.

CONCLUSION

Although both radiographic damage and functional limitations increase over time in AS, the relative contribution of radiographic damage to functional limitations is lower among patients with longstanding AS than with early AS, suggesting patients may accommodate to limited flexibility. Damage in different skeletal regions impacts functioning over the duration of AS. Functional limitations due to comorbidity supervene in late AS.

An exploration of the inter- and intra-rater reliability of the Bath Ankylosing Spondylitis Metrology Index

The aim of this study was to explore the inter- and intra-observer reliability of the Bath Ankylosing Spondylitis Metrology Index (BASMI) across raters from different clinical centres using a consensus-based standardised approach to assessment. One hundred thirty BASMI assessments were completed on the same day using a partially balanced incomplete block design. Thirteen physiotherapists from 10 hospitals assessed 26 participants (19 patients, 7 healthy volunteers). Each therapist assessed six participants and, to assess intra-observer reliability, performed repeat assessments on four. Overall, the mean (standard deviation; SD) BASMI total score was 3.11 (2.04). The constituent components of SD were 0.37 ('residual' inconsistency, i.e. between observer), 0.34 (between replicates), at least 0.06 (between observer means) and 2.03 (between participants). This suggests that the repeatability of BASMI assessments is 0.95 if the same observer is used and 1.05 if different observers are used. Inter-physiotherapist residual SDs for individual constituent component scores were largest for the modified Schober measurement and lumbar side flexion; intra-observer SDs showed similar patterns, although they were smaller for tragus to wall and lumbar side flexion. We found excellent inter-observer and intra-observer reliability, with most of the variability in BASMI scores being between participants. However, for repeat assessments of the same participant by the same physiotherapist, differences in BASMI of 1.0 or less are within bounds of error; likewise, differences of 1.0 or less are within the bounds of error if different physiotherapists perform the assessments. Only changes above these limits can be confidently interpreted as true clinical changes.

Clinical and immunogenetic prognostic factors for radiographic severity in ankylosing spondylitis

OBJECTIVE

To improve prognostic ability in ankylosing spondylitis (AS), we sought to identify demographic, clinical, and immunogenetic characteristics associated with radiographic severity in a large cohort of patients.

METHODS

Patients with AS for > or =20 years were enrolled in a cross-sectional study (n = 398). Pelvic and spinal radiographs were scored using the Bath Ankylosing Spondylitis Radiology Index for the spine (BASRI-s), and radiographic severity was measured as the BASRI-s/duration of AS. Clinical factors and HLA-B, DR, DQ, and DP alleles associated with the highest quartile of the distribution of radiographic severity were identified by first using random forests and then using multivariable logistic regression modeling. Similar procedures were used to identify factors associated with the lowest quartile of radiographic severity.

RESULTS

Radiographic severity (being in the top quartile of BASRI-s/duration of AS) was associated with older age at onset of AS (odds ratio [OR] 1.10 per year), male sex (OR 1.90), current smoker (OR 4.72), and the presence of HLA-B*4100 (OR 11.73), DRB1*0804 (OR 12.32), DQA1*0401 (OR 5.24), DQB1*0603 (OR 3.42), and DPB1*0202 (OR 23.36), whereas the presence of DRB1*0801 was strongly negatively associated (OR 0.03). Being in the lowest quartile of BASRI-s/duration of AS was also less likely among those with an older age at onset of AS (OR 0.94 per year), men (OR 0.28), and current smokers (OR 0.29).

CONCLUSION

The accuracy of the prognosis of radiographic severity in AS is improved by knowing the age at disease onset, sex, smoking history, and the presence of HLA-B*4100, DRB1*0804, DQA1*0401, DQB1*0603, DRB1*0801, and DPB1*0202 alleles.

Dynamic angular three-dimensional measurement of multisegmental thoracolumbar motion in vivo

STUDY DESIGN

Method validation and in vivo motion segment study.

OBJECTIVE

To determine in healthy subjects in vivo intervertebral segmental kinematics and coupled motion behavior in all 3 planes simultaneously for 3 segments and to evaluate whether these results differ from those in the normal population according to the literature.

SUMMARY OF BACKGROUND DATA

Few studies have provided a direct invasive approach to investigate segmental kinematics in vivo. Dynamic recordings of 3-dimensional segmental motion patterns of adjacent segments have rarely been reported. To date, no studies have examined the 3-dimensional segmental movements of the thoracolumbar junction in vivo in detail.

METHODS

K-wires were inserted into the Th11, Th12, L1, and L2 spinous processes of 21 healthy subjects. Ultrasound markers and sensors were attached to the k-wires. Real-time motion data were recorded during standardized ranging exercises. Errors caused by the k-wires, and the static and dynamic accuracy of the system, were considered.

RESULTS

Large intersubject variation was found in all of the exercises. The average ranges of motion from Th11 to L2 were 18.7 degrees for flexion-extension, 13.5 degrees for one-sided lateral bending, and 1.8 degrees for one-sided axial rotation. Coupled-motion patterns among the subjects showed a coupled flexion in active lateral bending and a coupled extension in active rotation, but the results were inconsistent for active extension and flexion.

CONCLUSION

This method offered accurate multisegmental dynamic-recording facilities. The dynamic exercises showed high reproducibility. The ranges of motion for extension/flexion and lateral bending differed from those reported in previous studies. The coupling patterns were only partly consistent because of large interindividual variation. The measurement error was comparable with that of other invasive methods.

Assessment and treatment of ankylosing spondylitis: current status and future directions

PURPOSE OF REVIEW

To summarize the latest developments in outcome assessment and treatment in ankylosing spondylitis.

RECENT FINDINGS

A number of clinical and radiological outcome measures used in the assessment of patients with ankylosing spondylitis have recently been critically reappraised and compared, to assist in the interpretation of study results and to guide choices for outcome measures in clinical trials. Clinical tools for assessing spinal mobility, peripheral joint disease and enthesitis, and radiograph and MRI scoring methods have been reviewed for validity and test performance in patients with ankylosing spondylitis. Experience with the use of anti-tumour necrosis factor-alpha therapies for ankylosing spondylitis continues to grow, and longer term data show these treatments continue to be effective and safe to 5 years of therapy.

SUMMARY

As measurement tools for disease state and progression in ankylosing spondylitis are refined, the assessment of response to therapy improves, with the aim that real effect on structural damage in ankylosing spondylitis may be detected.

Association between radiographic damage of the spine and spinal mobility for individual patients with ankylosing spondylitis: can assessment of spinal mobility be a proxy for radiographic evaluation?

OBJECTIVE

To demonstrate the association between various measures of spinal mobility and radiographic damage of the spine in individual patients with ankylosing spondylitis, and to determine whether the assessment of spinal mobility can be a proxy for the assessment of radiographic damage.

METHODS

Radiographic damage was assessed by the mSASSS. Cumulative probability plots combined the radiographic damage score of an individual patient with the corresponding score for nine spinal mobility measures. Receiver operating characteristic analysis was performed to determine the cut off level of every spinal mobility measure that discriminates best between the presence and absence of radiographic damage. Three arbitrary cut off levels for radiographic damage were investigated. Likelihood ratios were calculated to explore further the diagnostic properties of the spinal mobility measures.

RESULTS

Cumulative probability plots showed an association between spinal mobility measures and radiographic damage for the individual patient. Irrespective of the chosen cut off level for radiographic progression, lateral spinal flexion and BASMI discriminated best between patients with and those without structural damage. Even the best discriminatory spinal mobility assessments misclassified a considerable proportion of patients (up to 20%). Intermalleolar distance performed worst (up to 30% misclassifications). Lateral spinal flexion best predicted the absence of radiographic damage, and a modified Schober test best predicted the presence of radiographic damage.

CONCLUSION

This study unequivocally demonstrated a relationship between spinal mobility and radiographic damage. However, spinal mobility cannot be used as a proxy for radiographic evaluation in an individual patient.

Two Exercise Interventions for the Management of Patients with Ankylosing Spondylitis

OBJECTIVE

The purpose of this clinical trial was to evaluate the impact of a 4-month comprehensive protocol of strengthening and flexibility exercises developed by our research group versus conventional exercises for patients with Ankylosing Spondylitis (AS) on functional and mobility outcomes.

DESIGN

Randomized controlled trial. Forty-five patients diagnosed with AS according to the modified criteria of New York were allocated to control or experimental groups using a random numbers table. The control group was treated with a conventional protocol of physical therapy in AS, whereas the experimental group was treated with the protocol suggested by our research group. The conventional intervention consisted of 20 exercises: motion and flexibility exercises of the cervical, thoracic, and lumbar spine; stretching of the shortened muscles; and chest expansion exercises. The experimental protocol is based on the postural affectation of the AS and the treatment of the shortened muscle chains in these patients according to the Global Posture Reeducation (GPR) method. This intervention employs specific strengthening and flexibility exercises in which the shortened muscle chains are stretched and strengthened. The study lasted 4 mos. During this period, patients received a weekly group session managed by an experienced physiotherapist. Each session lasted an hour, and there were 15 total sessions. Changes in activity, mobility, and functional capacity were evaluated by an assessor blinded to the intervention, using the following previously validated scores from the Bath group: BASMI (tragus to wall distance, modified Schober test, cervical rotation, lumbar side flexion, and intermalleolar distance), BASDAI (The Bath Ankylosing Spondylitis Disease Activity Index), and BASFI (The Bath Ankylosing Spondylitis Functional Index).

RESULTS

Both groups showed an improvement (prepost scores) in all the outcome measures, mobility measures of the BASMI index, as well as in BASFI and BASDAI indexes. In the control group, the improvement in tragus to wall distance (P=0.009) and in lumbar side flexion (P=0.02) was statistically significant. Although the rest of the outcomes also improved, they did not reach a significant level (P>0.05). In the experimental group, the improvement in all the clinical measures of the BASMI index (P<0.01) and in the BASFI index (P=0.003) was statistically significant. The intergroup comparison between the improvement (prepost scores) in both groups showed that the experimental group obtained a greater improvement than the control group in all the clinical measures of the BASMI index, except in tragus to wall distance, as well as in the BASFI index.

CONCLUSIONS

The experimental protocol developed by our research group, based on the GPR method and specific strengthening and flexibility exercises of the muscle chains, offers promising results in the management of patients suffering from AS. Further trials on this topic are required.

Evaluation of the smallest detectable difference in outcome or process variables in ankylosing spondylitis

OBJECTIVE

To evaluate the smallest detectable difference (SDD) of symptomatic outcome or process variables in ankylosing spondylitis (AS) patients from various countries.

METHODS

Thirty consecutive AS patients with axial involvement were recruited from 1 center in each of 4 countries (Spain, Morocco, France, The Netherlands), for a total of 120 patients. Fourteen variables were studied in 6 domains: pain (3 variables), stiffness (1 variable), function (2 variables), spinal mobility (3 variables), patient global assessment (4 variables), and the domain of enthesiopathy (1 variable). All patients were evaluated twice within a 1-week period during which no clinical or therapeutic change occurred. Intracenter reliability was evaluated using the intraclass correlation coefficient (ICC). The SDD was determined using the Bland-Altman method.

RESULTS

Of the 14 variables evaluated in the 120 patients (82% males, 42 +/- 12 years old, with a mean disease duration of 17 +/- 13 years), only the SDD for the variable occiput-to-wall distance showed statistically significant difference among centers. For the entire group, the SDD, expressed as percentage of the range of the variable, varied from 10% (Mander enthesis index) to 39% (spinal pain at night last week). The intraobserver reliability was good (ICC > 0.80) except for the variables morning stiffness and modified Schober test (ICCs of 0.76 and 0.60, respectively).

CONCLUSION

This study suggests that the evaluation of AS patients is homogenous and reliable in different centers of different European and North African countries. Evaluation of the SDD of the symptomatic outcome or process variables is a starting point to determine the minimum clinically important difference, permitting the presentation of results of clinical studies on an individual basis.

Development of a radiographic index to assess the tarsal involvement in patients with spondyloarthropathies

OBJECTIVE

To develop and test an index to evaluate the radiographic changes that occur in the tarsus and adjacent areas of the foot in patients with spondyloarthropathies (SpA).

METHODS

The spondyloarthropathy tarsal radiographic index (SpA-TRI) was developed in three consecutive steps: (a) detection of descriptors after reviewing 70 radiographic files; (b) descriptor gradation and subsequent modifications performed by a consensus committee, and (c) interobserver variability assessed by three blinded and independent observers on 272 radiographs: anteroposterior 118, lateral 90, oblique 64 from 121 patients with SpA, and intraobserver variability on 75 radiographs from 25 patients with SpA. Statistical analysis included percentage of agreement and kappa test. SpA-TRI score ranges from 0 to 4 (0=normal; 1=osteopenia or suspicious findings; 2=definite joint space narrowing, bony erosion(s), periosteal whiskering, or enthesophyte(s) in the plantar fascia or Achilleal tendon attachments; 3=para-articular enthesophyte(s); 4=bony ankylosis (joint space fusion or complete bridging)).

RESULTS

Complete agreement for every evaluation was >40%, and discordance >1 grade was <15%. The kappa scores among the three observers were acceptable for all the single projections: oblique (0.52, 0.36, 0.35), lateral (0.50, 0.42, 0.56), and anteroposterior (0.40, 0.41, 0.21) views. The combination of lateral and oblique views achieved the highest concordance rates (0.72, 0.33, 0.66), surpassing that of the three projections altogether (0.34, 0.58, 0.37). In every case the concordance was comparable with that of sacroiliac joints (0.47, 0.41, 0.34); intraobserver concordance showed a similar trend.

CONCLUSION

The SpA-TRI is an index that includes the most prominent features of tarsal disease and adjacent areas of the foot in SpA and grades them accordingly, it has an adequate reproducibility, and is suitable for use with two or more projections, preferably the combination of oblique and lateral.

Validity, reliability, and responsiveness of the fingertip-to-floor test

OBJECTIVE

To evaluate the validity, reliability, and responsiveness of the fingertip-to-floor test to assess total mobility when bending forward in standing position.

DESIGN

Experimental, prospective, correlational.

SETTING

Rehabilitation and radiology departments in a university hospital in France.

PARTICIPANTS

Ten patients (6 women, 4 men; mean age, 42yr) with chronic low back pain (LBP) in the validity study; 32 LBP patients (16 women, 16 men; mean age, 52yr) in the reliability study; and 72 LBP patients (22 women, 50 men; mean age, 30yr) in the responsiveness study.

INTERVENTIONS

Dynamic radiographs and fingertip-to-floor test.

MAIN OUTCOME MEASURES

For the validity study, 2 lateral radiographs of the upper dorsal spine, 1 in neutral position, and then 1 in full trunk flexion, were made. Validity was assessed by means of Spearman's correlation coefficient. Reliability was studied by using intraclass correlation coefficient (ICC) and the Bland and Altman method. Responsiveness was assessed by the effect size and the standardized response mean (SRM).

RESULTS

The Spearman's correlation coefficient for trunk flexion assessed by the test and the radiologic measure was excellent (r(s) = -.96). The intra- and interobserver reliability were excellent (ICC = .99). The Bland and Altman method showed no systematic trend. The values observed for the test were .97 for SRM and .87 for effect size.

CONCLUSIONS

Because the fingertip-to-floor test has excellent validity, reliability, and responsiveness, it can be used in clinical practice and therapeutic trials.

Factors associated with hip joint rotation in former elite athletes

OBJECTIVES

To study factors associated with passive hip rotation range of motion (ROM) in former elite male athletes.

METHODS

Athletes were interviewed about hip pain, disability, lifetime occupational loading, and athletic training. The passive hip rotation was measured with a Myrin inclinometer in 117 former elite male long distance runners, soccer players, weight lifters, and shooters aged 45-68 years. Magnetic resonance imaging was used to detect hip osteoarthritis.

RESULTS

There were no differences in passive hip rotation ROM between the four athlete groups nor between diverging lifetime loading patterns associated with occupational or athletic activities. Among the subjects without hip osteoarthritis, hip pain, and hip disability according to a stepwise linear regression analysis, the only factor that was associated with the passive hip rotation ROM was body mass index (BMI), explaining about 21% of its variation. Subjects with high BMI had lower passive hip rotation ROM than those with low BMI. There was no right-left difference in the mean passive hip rotation ROM in subjects either with or without hip osteoarthritis as determined by magnetic resonance imaging. Nevertheless, hip rotation ROM was clearly reduced in a few hips with severe caput deformity.

CONCLUSIONS

Long term loading appears to have no association with passive hip rotation ROM. On the other hand, the hip rotation value was lower in subjects with high BMI than in those with low BMI. A clear right-left difference in hip rotation was found only in those subjects who, according to our magnetic resonance imaging criteria, had severe hip osteoarthritis. These findings should be taken into account when hip rotation ROM is used in the clinical assessment of hip joints.

Measurement of sacroiliac joint stiffness in peripartum pelvic pain patients with Doppler imaging of vibrations (DIV)

OBJECTIVES

The research question of the present study was: are sacroiliac joint stiffness levels of peripartum pelvic pain patients different from those of healthy subjects?

STUDY DESIGN

A cross-sectional comparative sacroiliac joint stiffness analysis of peripartum pelvic pain patients with healthy subjects. In previous studies we introduced a new technique, Doppler imaging of vibrations (DIV), to assess sacroiliac joint stiffness using colour Doppler imaging and vibrations. The measurements were performed on a group of peripartum pelvic pain patients (n=56) and on a control group (n=52). The differences in sacroiliac joint stiffness between the patient group and the control group were tested statistically by means of the Wilcoxon's two sample test, the chi-square test and Student's t-tests.

RESULTS

Both patients and controls displayed stiff as well as unstiff joints with no significant difference. There was a significant difference between the groups with regard to the relative difference of sacroiliac joint stiffness between left and right.

CONCLUSIONS

A diagnostic tool which can possibly be developed in the future could demonstrate an objective finding among women with peripartum pelvic pain. DIV is easy to apply and non-invasive. Asymmetric stiffness of the sacroiliac joints seems to be more directly related to low back pain and pelvic pain, not the stiffness level of a single sacroiliac joint.

Aortic root disease and valve disease associated with ankylosing spondylitis

OBJECTIVES

This study sought to determine the prevalence, characteristics, relation to clinical features and evolution of aortic root disease and valve disease associated with ankylosing spondylitis (AKS).

BACKGROUND

Aortic root disease and valve disease are common in patients with AKS, but their clinical and prognostic implications have not been well defined.

METHODS

Forty-four outpatients with AKS and 30 age- and gender-matched healthy volunteers underwent initial transesophageal echocardiography and rheumatologic evaluations. Twenty-five patients underwent clinical and echocardiographic follow-up 39+/-10 months later.

RESULTS

Aortic root disease and valve disease were common in patients (82%) as compared with controls (27%; p < 0.001). Aortic root thickening, increased stiffness and dilatation were seen in 61%, 61% and 25% of patients, respectively. Valve thickening (41% for the aortic and 34% for the mitral valve) manifested predominantly (74%) as nodularities of the aortic cusps and basal thickening of the anterior mitral leaflet, forming the characteristic subaortic bump. Valve regurgitation was seen in almost half of patients, and 40% had moderate lesions. Except for the duration of AKS, aortic root disease and valve disease were unrelated to the activity, severity or therapy of AKS. During follow-up of 25 patients, in up to 24% new aortic root or valve abnormalities developed, in 12% existing valve regurgitation worsened significantly and in 20% abnormalities resolved. Twenty percent of patients developed heart failure, underwent valve replacement, had a stroke or died, as compared with 3% of control subjects.

CONCLUSIONS

Aortic root disease and valve disease are common in patients with AKS, are unrelated to clinical features of AKS, can resolve or progress over time and are associated with clinically important cardiovascular morbidity.

Fifteen months' follow-up of intensive inpatient physiotherapy and exercise in ankylosing spondylitis

Long-term effects of three or four-week inpatient physiotherapy and exercise courses were studied in 141 adult patients with ankylosing spondylitis (AS). Eight cervical and thoracolumbar range of motion (ROM) measurements and straight leg raise test, vital capacity (VC) and fitness index were measured at the beginning and end of an intensive course and 15 months later. All nine mobility measurements, vital capacity and fitness index were significantly improved after the course. Fifteen months later only chest expansion and vital capacity had significantly deteriorated from the baseline, while CR, FFD and fitness index were still significantly better. Disease duration did not influence treatment results. We conclude that it is possible by means of intensive rehabilitation courses to prevent for more than one year deterioration of spinal function and fitness in AS patients irrespective of disease duration.

Age and spinal mobility in ankylosing spondylitis

Mobility measurements of spine, chest, hips, and shoulder in 73 adult males with ankylosing spondylitis (AS) were correlated with the duration of disease. Several mobility tests showed a significant correlation with the duration of AS, but after adjustment for age, only rotation of the thoracolumbar spine maintained a highly significant correlation. It is concluded that age has a strong effect on the mobility tests. Rotation of the thoracolumbar spine seems to be a valid measure for AS-specific changes.

The relative value of spinal and thoracic mobility measurements in ankylosing spondylitis

The relative value of nine spinal and thoracic mobility measurements was investigated in 73 male patients with ankylosing spondylitis (AS). The value of a test was obtained by the relative ranks of validity, reliability and sensitivity to change. Validity was determined as age-adjusted correlation of the test result with AS-specific radiological changes in the lumbar spine. Reliability was determined as inter-observer error. Sensitivity to change was determined as change in test result during an intensive rehabilitation course. The five most valuable tests were rotation of the thoracolumbar spine (TR), finger-to-floor distance (FFD), the Schober test, thoracolumbar flexion and occiput-to-wall distance. Of these, FFD had high reliability and sensitivity ranks, but poor correlation with AS-specific spinal changes. TR had high validity and sensitivity ranks, and improvement of the measurement technology would probably result in a superior test for the follow-up of AS. Chest expansion and vital capacity had low ranks in all comparisons.