Interaction effects of significant risk factors on low bone mineral density in ankylosing spondylitis

Background

To analyze individually and interactively critical risk factors, which are closely related to low bone mineral density (BMD) in patient with ankylosing spondylitis (AS).

Methods

A total of 249 AS patients who visited China-Japan Friendship Hospital were included in this training set. Patients with questionnaire data, blood samples, X-rays, and BMD were collected. Logistic regression analysis was employed to identify key risk factors for low BMD in different sites, and predictive accuracy was improved by incorporating the selected significant risk factors into the baseline model, which was then validated using a validation set. The interaction between risk factors was analyzed, and predictive nomograms for low BMD in different sites were established.

Results

There were 113 patients with normal BMD, and 136 patients with low BMD. AS patients with hip involvement are more likely to have low BMD in the total hip, whereas those without hip involvement are more prone to low BMD in the lumbar spine. Chest expansion, mSASSS, radiographic average grade of the sacroiliac joint, and hip involvement were significantly associated with low BMD of the femoral neck and total hip. Syndesmophytes, hip involvement and higher radiographic average grade of the sacroiliac joint increases the risk of low BMD of the femoral neck and total hip in an additive manner. Finally, a prediction model was constructed to predict the risk of low BMD in total hip and femoral neck.

Conclusions

This study identified hip involvement was strongly associated with low BMD of the total hip in AS patients. Furthermore, the risk of low BMD of the femoral neck and total hip was found to increase in an additive manner with the presence of syndesmophytes, hip involvement, and severe sacroiliitis. This finding may help rheumatologists to identify AS patients who are at a high risk of developing low BMD and prompt early intervention to prevent fractures.

Prevalence of sacroiliitis among patients referred for hip MR arthrography

OBJECTIVE

To determine the prevalence of sacroiliitis among patients who have been referred for MR arthrography.

MATERIALS AND METHODS

A retrospective search identified 130 consecutive MR arthrograms of the hip performed on a 1.5T Siemens Avanto at our institution from August 2013 to August 2014. Four studies were excluded due to the absence of a coronal short tau inversion recovery sequence of the pelvis, leaving 126 studies for analysis. A musculoskeletal radiology fellow and three attending musculoskeletal radiologists reviewed the images for the presence of bone marrow edema affecting the sacroiliac joints. Only cases of bone marrow edema meeting the Assessment of SpondyloArthritis international Society definition were considered positive. The two-tailed Fisher's exact test was used to compare the prevalence of positive MRI findings among age and gender groups. GraphPad InStat (GraphPad Software) was used for statistical calculations.

RESULTS

Patients less than 40 years of age demonstrated a statistically higher prevalence of positive MRI findings of sacroiliitis when compared to patients older than 40 (p = 0.0082). No difference in prevalence was found between genders. Overall prevalence of MRI signal alteration suggestive of sacroiliitis as defined by the Assessment of SpondyloArthritis international Society was 4.8%. Among the six patients with positive findings, two were subsequently diagnosed with spondyloarthritis.

CONCLUSION

Hip pain may be a presenting symptom of spondyloarthritis and attention should be paid to the sacroiliac joints during screening examinations, particularly in patients less than 40 years of age.

Development and validation of the spondyloarthritis radiography module for calibration of readers using the modified Stoke Ankylosing Spondylitis Spine Score

OBJECTIVE

To develop and validate a reference image module aimed at calibration of readers using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) to assess radiographic progression in spondyloarthritis.

METHODS

Our working group comprised 6 rheumatologists and 3 musculoskeletal radiologists. The following developmental steps were conducted: (1) review of the literature to identify aspects of the mSASSS requiring methodologic clarity; (2) independent assessment of baseline and 2-year radiographs from 25 patients using the mSASSS (pilot exercise); (3) development of a training module (the Spondyloarthritis Radiography [SPAR] module) that clarifies definitions, rules, and scoring methodology and a set of reference radiographic images; (4) scoring exercise 1 by 6 readers on 39 patients, where baseline and 2-year radiographs were scored blinded to time point; and (5) revision of the SPAR module followed by scoring exercise 2 conducted by the same 6 readers on 35 patients. Reliability of status and 2-year change scores was assessed by the intraclass correlation coefficient (ICC) method.

RESULTS

ICCs for change scores for the radiologist reader pair improved from 0.46 to 0.62 after minimal calibration with the SPAR module. Recalibration from exercise 1 to exercise 2 with the SPAR module led to substantial improvement in interreader reliability for change in mSASSS score from ICC 0.44 (range 0.31-0.62) to ICC 0.62 (range 0.34-0.84). Simultaneous assessment of anteroposterior and lateral lumbar radiographs did not enhance reliability or detection of progression.

CONCLUSION

Calibration according to the SPAR module led to improved reliability in the scoring of the mSASSS, even for expert readers.

High-pressure paint gun injury: clinical presentation and imaging findings

High-pressure paint gun injuries are potentially devastating injuries that require emergent surgical incision and drainage. They result from erroneous equipment operation and accidental injection of a variety of substances at pressures high enough to breach the skin. The largely benign superficial appearance masks the extent of the underlying injury. In the absence of an appropriate history, the radiologist must recognize the characteristic radiographic findings and suggest the diagnosis to the clinician.

Psychological correlates of self-reported disease activity in ankylosing spondylitis

OBJECTIVE

To investigate the role of psychological variables in self-reported disease activity in patients with ankylosing spondylitis (AS), while controlling for demographic and medical variables.

METHODS

Patients with AS (n = 294) meeting modified New York criteria completed psychological measures evaluating depression, resilience, active and passive coping, internality, and helplessness. Demographic, clinical, and radiologic data were also collected. Univariate and multivariate analyses were completed to determine the strength of the correlation of psychological variables with disease activity, as measured by the Bath AS Disease Activity Index (BASDAI).

RESULTS

In the multivariate regression analysis, the psychological variables contributed significantly to the variance in BASDAI scores, adding an additional 33% to the overall R-square beyond that accounted for by demographic and medical variables (combined R-square 18%). Specifically, arthritis helplessness and depression accounted for the most significant portion of the variance in BASDAI scores in the final model.

CONCLUSION

Arthritis helplessness and depression accounted for significant variability in self-reported disease activity beyond clinical and demographic variables in patients with AS. These findings have important clinical implications in the treatment and monitoring of disease activity in AS, and suggest potential avenues of intervention.

Magnetic resonance imaging findings in hematogenous osteomyelitis of the hip in adults

Hematogenous hip infections are rare in adults and the extent of infection into the bone or adjacent soft tissues may be underestimated, leading to inadequate surgical débridement. Using MRI, we sought to determine the extent of bone involvement and the presence of adjacent soft tissue abscesses in adults with hip osteomyelitis. We reviewed the records and MRIs in 11 adult patients (12 hips) with hematogenous osteomyelitis of the femoral head in 12 hips. Ten of 11 patients had one or more comorbidities. All patients underwent surgical débridement and received antibiotic therapy for 6 weeks. MRI revealed osteomyelitis distal to the femoral head in seven of 12 hips with extension into the medullary canal in three of these seven. Femoral head erosions were present in 10 hips, acetabulum osteomyelitis in 11, and acetabular erosions in six hips. Infection extended into adjacent soft tissues in eight of 12 hips. MRI demonstrated that the infection may extend distal to the femoral head or into the adjacent soft tissues. MRI may be useful for preoperative planning so that all regions affected by the infection can be treated.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Influence of cryosurgery on treatment outcome of low-grade chondrosarcoma

Successfully managing low-grade chondrosarcomas with margins considered less than wide would minimize the need for extensive reconstruction. We report our experience using cryotherapy as an adjuvant to treat patients with low-grade intracompartmental chondrosarcomas. Ten consecutive patients had intralesional resections including curettage, cryo-surgery, and polymethylmethacrylate application. Eight of these patients required prophylactic skeletal stabilization. We retrospectively reviewed the outcomes for tumor recurrence, disease progression, and complications. The Musculo-skeletal Tumor Society rating scale was used to evaluate functional outcome, and the mean score was 27 points (range, 25-30 points). The mean age of the patients was 54.4 years (range, 29-83 years), and the average followup was 38.5 months (range, 24-60 months). Patients were treated for lesions of the femur (n = 3), humerus (n = 3), scapula (n = 2), tibia (n = 1), and acetabulum (n = 1). There was no evidence of recurrence or metastases. At the latest followup, all patients were well, however, one patient had hardware loosening. In this small group of patients, intralesional resection with adjuvant cryoablation provided an alternative to more radical procedures for low-grade intracompartmental chondrosarcoma.

Radial head fractures: MRI evaluation of associated injuries

The purpose of this study was to evaluate the incidence of combined osteochondral and ligamentous injuries by magnetic resonance imaging (MRI) in 24 patients with an acute radial head fracture (Mason type II and III) without documented dislocation or tenderness at the distal radioulnar joint. Elbow radiographs (anteroposterior and lateral views) were obtained on all patients as well as magnetic resonance images in the sagittal, coronal, axial, axial oblique, and coronal oblique planes with the injured elbow in a splint. The incidence of associated injuries revealed by MRI was medial collateral ligament not intact in 13 of 24 (54.16%), lateral ulnar collateral ligament not intact in 18 of 24 (80.1%), both collateral ligaments not intact in 12 of 24 (50%), capitellar osteochondral defects in 7 of 24 (29.1%), capitellar bone bruises in 23 of 24 (95.83%), and loose bodies in 22 of 24 (91.67%). A high level of suspicion should be used when one is treating displaced or comminuted radial head fractures, because concurrent osteochondral injuries and/or ligamentous injuries may be present.