Genome-Wide Association Study of Adhesive Capsulitis Suggests Significant Genetic Risk Factors

AAOS 2024 best paper in the shoulder and elbow classification: watchful waiting provides higher value with similar functional outcomes to physical therapy for frozen shoulder: a prospective randomized controlled trial

BACKGROUND

Physical therapy remains a ubiquitous treatment modality for the management of frozen shoulder (adhesive capsulitis) despite limited high-level evidence supporting its use. Leveraging patient-reported outcome measures (PROMs) and healthcare costs, this study compared patient outcomes and value achieved through watchful waiting (WW) vs. physical therapy (PT) for conservative management of frozen shoulder.

METHODS

Patients in this prospective, parallel randomized controlled trial who were diagnosed with frozen shoulder were randomized 1:1 to WW or PT. All patients were offered therapeutic, intra-articular corticosteroid injections (CSIs). The primary outcome was the American Shoulder and Elbow Surgeons Score. Secondary outcomes included patient value (ie, 12-month American Shoulder and Elbow Surgeons score divided by healthcare costs), the Disabilities of the Arm, Shoulder, and Hand questionnaire, and Visual Analog Scale pain. Due to the confidentiality of internal hospital data, all economic outcomes were divided by an undisclosed constant to set the normalized study mean for direct costs to 1000; similarly, patient value was normalized to set the study mean to 100. Outcomes were assessed at baseline, 6 weeks, 3 months, 6 months, and 12 months using mixed-effects models, with sensitivity analyses adjusting for nonlinear improvement trajectories and CSIs.

RESULTS

Between November 2014 and November 2022, 175 patients were screened, 61 of whom (34.9%) were randomized to WW (31 patients) or PT (30 patients). Forty-seven patients (96%) received at least one CSI, with no significant difference in CSI administration between cohorts (P = .29). Relative to baseline scores, patients from both cohorts improved significantly at each time point for all PROMs (P < .05 for all), with no significant differences in PROMs between groups at any time point (P > .05 for all). However, compared to those assigned WW, patients randomized to PT incurred 10.0× higher costs (normalized mean difference: 1636; 95% CI: 967, 2304; P < .001) and achieved only 16.9% of the patient value (normalized mean difference: -147.0; 95% CI: -207.5, -86.5; P < .001). These results held across all sensitivity analyses.

CONCLUSION

Relative to WW, patients randomized to PT reported similar PROMs but incurred significantly higher direct costs (10.0×) and imposed a greater economic burden on the healthcare system (3.4-6.0×). Accordingly, WW resulted in significantly higher (5.9×) patient value than PT. Although additional high-level, multicenter studies are needed to corroborate these findings, the present study may support physicians and patients in pursuing the most appropriate treatment plan for each patient based on their individualized needs and preferences.

MR imaging signs of shoulder adhesive capsulitis: analysis of potential differentials and improved diagnostic criteria

OBJECTIVE

To evaluate the prevalence of shoulder adhesive capsulitis (AC) signs on MR studies of patients with various common shoulder conditions.

METHODS

MR images of 316 patients were retrospectively evaluated. Patients were divided into three groups: controls (66 patients), clinical AC (63 patients), and study group (187 patients). The final diagnosis of AC was reached clinically. The study group was composed of patients with focal and massive rotator cuff tears, active hydroxyapatite deposition disease, fractures around the shoulder, and post-surgery. The following AC signs were evaluated: inferior glenohumeral ligament (IGHL) thickening; coracohumeral ligament (CHL) thickening; and hyperintensity of the inferior glenohumeral ligament, which was graded in four classes.

RESULTS

The IGHL signal intensity was statistically higher in patients with fractures than in controls (P = 0.008). There was no statistically significant difference in IGHL signal between the AC group and patients with massive rotator cuff tears and active hydroxyapatite deposition disease (P > 0.1). IGHL thickness in patients with fractures, massive rotator ruptures, and active hydroxyapatite deposition disease was significantly higher compared to controls (P < 0.02) and significantly lower compared to the AC group (P < 0.0001). Based on these findings, a grading system for fibro-inflammatory capsular changes is proposed.

CONCLUSION

MR AC signs are frequent in patients with shoulder conditions other than AC; however, in these patients, capsular changes are less prominent than in patients with clinical AC.

An Updated Overview of Risk Factors for Shoulder Stiffness

A painful reduction in shoulder mobility, known as "shoulder stiffness", can occur both as a primary idiopathic condition and as a secondary condition, for example, following surgical procedures. Various factors can contribute to the development of primary shoulder stiffness. In this review we summarize the pathophysiological mechanisms, genetic influences, endocrine disorders, metabolic conditions, as well as other diseases and medical-therapeutic approaches that might have an impact on the development of primary shoulder stiffness.

The S2e Guideline on Shoulder Stiffness

The clinical picture of "frozen shoulder" is still poorly understood. In order to present the current state of knowledge on aetiology, diagnosis, and treatment, and to provide recommendations for the professional groups involved, a working group was formed by the DGOU and the DVSE to create a German language, evidence-based guideline, which was published in 2022 by the AWMF. The following summarises the development and the most important results.

Decreased rotator cuff muscle cross-sectional areas in subjects with adhesive capsulitis: a study comparing male and female subjects

OBJECTIVE

To compare rotator cuff (RC) muscle cross-sectional areas (CSA) in subjects with adhesive capsulitis (AC) to age- and sex-matched controls.

MATERIALS AND METHODS

We retrospectively analyzed 97 shoulder MRIs or MR arthrography studies, of which 42 were clinically diagnosed with AC (27 female, 15 male) and 55 were age- and sex-matched controls (38 female, 17 male). All AC subjects underwent imaging ≥ 6 months after symptom onset. All imaging was examined to exclude RC full-thickness tears and prior surgery. A standardized T1 sagittal MR image was segmented in each subject to obtain the CSA of subscapularis (SSC), supraspinatus (SSP), and infraspinatus (ISP) muscles. Differences in CSAs between AC and control subjects were analyzed by sex (females and males separately) and all subjects combined.

RESULTS

AC females had significantly decreased SSC (P = 0.002) and total (P = 0.006) CSAs compared to controls. Male AC subjects showed decreased SSC (P = 0.044), SSP (P = 0.001), and total (P = 0.005) CSAs. Across all subjects, male and female, the AC cohort had significantly decreased SSC (P = 0.019) and total (P = 0.029) CSAs compared to controls.

CONCLUSION

Decreased RC muscle CSAs were present in AC subjects with ≥ 6 months of symptom duration, with decreased SSC and total CSAs in male and female subjects, and decreased SSP CSA in males.

Frozen shoulder. An overview of pathology and biology with hopes to novel drug therapies

Frozen shoulder (FS) is a common disorder characterized by spontaneous onset of shoulder pain accompanied by progressive loss of range-of-motions. The cause of FS is still unclear, and radical therapy has not been established. With the final aim of preventing or curing FS at an earlier stage, we reviewed the pathological and biological features of this disease. Many studies indicate that the main pathology of FS is inflammation initially and fibrosis later. There are inflammatory cytokines, immune cells, fibrotic growth factors, and type-III collagen in the synovium and the joint capsule. The immune cell landscape switches from the macrophages to T cells. Activated fibroblasts seem to regulate the inflammatory and fibrotic processes. The imbalance between matrix metalloproteinases and tissue inhibitors of metalloproteases might promote fibrosis. Additionally, advanced glycation end-products are noted in the FS synovium. Diabetes mellitus and hypothyroidism are closely related to the development of FS. In terms of nonsurgical treatment, oral or intra-articular glucocorticoids are the only drugs that provide early benefit. Some other anti-inflammatory or antifibrotic drugs may potentially control the FS, but have not been proven effective in the clinical setting. Future studies should be targeted to develop steroid-sparing agents that inhibit biological events in FS.

Type 2 diabetes and fasting glycemic traits are causal factors of frozen shoulder: a 2-sample Mendelian randomization analysis

BACKGROUND

The causal relationship between type 2 diabetes (T2D) and frozen shoulder is unclear. This study aims to explore the genetic causal association between T2D and glycemic traits (fasting glucose [FG], fasting insulin [FI], glycated hemoglobin [HbA1c], and 2-hour postprandial glucose [2hGlu]) on frozen shoulder.

METHODS

Using 2-sample Mendelian randomization (MR), we analyzed nonconfounded estimates of the effects of T2D and glycemic traits on frozen shoulder. Single-nucleotide polymorphisms (SNPs) strongly associated (P < 5 × 10-8) with exposures from genome-wide association studies (GWAS) were identified. We employed fixed effect mode inverse variance weighting (IVW-FE), random effect mode IVW (IVW-MRE), MR-Egger, and weighted median to assess the association of exposures and outcome. Sensitivity analysis was conducted to test for heterogeneity and multidirectionality bias in MR.

RESULTS

We found a significant genetic causal correlation between T2D (IVW-MRE P = .007, odds ratio [OR] 1.093, 95% confidence interval [CI] 1.03-1.16), FG (IVW-FE P < .001, OR 1.455, 95% CI 1.173-1.806), and frozen shoulder, but no evidence for causal correlation between FI, HbA1c, and 2hGlu and frozen shoulder. Although there was certain heterogeneity, sensitivity analysis reveals no deviation from the MR assumptions.

CONCLUSION

This study supports a genetic causal relationship between T2D and FG and frozen shoulder.