The study aimed to evaluate posterior capsule edema on MRI in patients with adhesive capsulitis compared to controls. Posterior capsule edema was present in 66.7% of adhesive capsulitis patients versus 17.5% of controls. Multivariate analysis found that posterior capsule edema, coracohumeral ligament edema, and increased axillary pouch thickness were significant independent predictors of adhesive capsulitis. The combination of these MRI findings produced a strong model for distinguishing adhesive capsulitis from normal shoulders.

1. POSTERIOR CAPSULE EDEMA IN
ADHESIVE CAPSULITIS: COMPARISON
WITH ESTABLISHED NON-CONTRAST MRI
FINDINGS AND MULTIVARIABLE ANALYSIS
Abdillah Budi Ksatria
211231007

3. Introduction
• 1.The study aimed to evaluate the presence of posterior glenohumeral capsule edema in
comparison to other MRI findings in adhesive capsulitis (AC).
• 2.The study involved a retrospective search for subjects who received fluoroscopically
guided intra-articular corticosteroid injections for AC and had an MRI within 6 months
prior to the injection.
• 3.The study group was compared with a control group who underwent similar procedures
but did not have AC.
• 4. Results indicated that posterior capsule edema, coracohumeral ligament (CHL) edema,
and axillary pouch (glenoid) thickness were significant independent predictors ofAC.
• 5.The study concluded that posterior joint capsule edema may be helpful to confirmAC,
and the combined presence of posterior capsular edema, axillary pouch (glenoid)
thickness, and CHL edema was highly predictive for adhesive capsulitis on MRI.

4. Materials and Methods
• - Initial search yielded 273 fluoroscopically guided glenohumeral injections
• - 107 injections for adhesive capsulitis, 57 met inclusion/exclusion criteria
• - Inclusion: non-contrast MRI within 6 months prior to injection
• - Exclusion: full-thickness rotator cuff tear, severe glenohumeral arthritis, acromioclavicular osteoarthritis, displaced
labral tears, calcific tendinitis, fracture/trauma, prior shoulder surgery
• - Control group matched for age, sex, and side from 489 non-contrast shoulder MRI patients
• - Exclusion criteria for control group: history of adhesive capsulitis, similar MRI findings as adhesive capsulitis group
• - MRIs performed on GE Healthcare and Siemens 1.5- and 3-T magnets
• - Qualitative and quantitative variables analyzed by two musculoskeletal radiologists
• - Interobserver agreement calculated using ICC for continuous variables and Kappa for categorical variables
• - Statistical analysis includedT-test, Chi-square test, Fisher’s exact test, logistic regression, ROC curve, and AUC
calculation

5. StatisticalAnalysis
• -The statistical analysis included comparisons between cases and controls using Student'sT-test for
continuous data and Chi-square or Fisher's exact test for categorical data.
• - A two-tailed p-value of < 0.05 was considered statistically significant in the analysis.- Optimal cutoff
values for quantitative variables were determined by maximizingYouden's J index to balance sensitivity
and specificity.
• - Multivariable logistic regression analysis was performed, including variables with p < 0.05 from the
univariate comparison of cases and controls.
• - A receiver operating characteristic (ROC) curve was plotted using significant predictors from the
multivariable logistic regression, with an area under the curve (AUC) calculated to assess the model's
predictive accuracy.
• -The statistical analysis aimed to identify significant independent predictors of adhesive capsulitis and
evaluate the diagnostic performance of the combined MRI findings in distinguishing cases from controls.
• -The study's statistical approach provided a robust framework for analyzing the MRI data and determining
the predictive value of posterior capsule edema, CHL edema, and axillary pouch thickness in diagnosing
adhesive capsulitis.

9. Results
• - 57 subjects with adhesive capsulitis and 57 matched controls
• - Mean age 52 ± 7 years, 37 females and 20 males, 22 right and 35 left shoulders
• - Posterior capsule edema present in 38/57 (66.7%) in adhesive capsulitis group vs.
10/57 (17.5%) in control group (p < 0.001)
• - RI fat replacement most common qualitative finding in adhesive capsulitis group
(68.4%)
• - All established qualitative MRI findings more common in adhesive capsulitis
group except teres minor atrophy
• - Subcoracoid fat replacement and teres minor edema more common in adhesive
capsulitis group, but not statistically significant

14. Discussion
• - Posterior capsule edema, along with coracohumeral ligament (CHL) edema and axillary pouch (glenoid) thickness, were significant independent
predictors of adhesive capsulitis.
• -The combination of these variables produced a strong model for distinguishing cases of adhesive capsulitis from controls, with an area under the curve
(AUC) of 0.860.
• - Optimal cutoff values for CHL, axillary pouch (humeral), axillary pouch (glenoid), and axillary pouch (total) thickness were identified.- Posterior capsule
edema demonstrated a sensitivity of 66.7% and a specificity of 82.5% for detecting adhesive capsulitis.
• -The study emphasizes the clinical relevance of posterior capsule edema as an imaging marker for capsulitis, aiding in the differentiation of patients
with adhesive capsulitis from those without.
• - Interobserver agreement for posterior capsule and axillary pouch edema was substantial, enhancing the reliability of these MRI findings.
• -The pathogenesis of adhesive capsulitis involves inflammatory contracture of the shoulder joint capsule, supported by findings of synovial
proliferation and hypervascular changes in the axillary pouch.
• - Prior literature has also highlighted the involvement of the posterior capsule in adhesive capsulitis, further validating the significance of posterior
capsule edema as a diagnostic marker.
• - Limitations of the study include the lack of pathological confirmation of inflammation in the posterior capsule and the retrospective nature of patient
selection, which could introduce bias.
• - Despite these limitations, the study concludes that posterior joint capsule edema is a valuable MRI finding for diagnosing adhesive capsulitis,
especially when combined with other significant predictors like axillary pouch thickness and CHL edema.