The association of metabolic syndrome markers with adhesive capsulitis

Genetic insights into the association between serum cytokines and frozen shoulder risk: A bidirectional mendelian randomization study

BACKGROUND

Although existing studies have indicated a connection between chronic low-grade inflammation and the onset of frozen shoulder (FS), the precise causal relationship between distinct circulating inflammatory factors and FS has yet to be thoroughly evaluated. In this study, we employed a bidirectional two-sample Mendelian randomization (MR) analysis to investigate the potential causal relationship between systemic cytokines and FS.

METHODS

A genome-wide association dataset comprising 41 serum cytokines from 8,293 individuals of Finnish descent was utilized, along with FS data from the UK Biobank included 10,104 FS cases and 451,099 controls. The primary MR method was the inverse variance weighted approach, and four additional MR techniques (MR-Egger, weighted median, simple mode, and weighted mode) were also employed to support and validate the findings. Heterogeneity and horizontal pleiotropy assessments were assessed using Cochrane's Q and MR-Egger intercept tests. Moreover, a series of sensitivity analyses were conducted to strengthen the accuracy and credibility of these findings.

RESULTS

Based on the IVW method, genetically predicted increasing levels of growth regulated oncogene alpha (GROa) (OR=1.08, 95 % CI 1.02-1.13, P=0.005), interferon gamma-induced protein 10 (IP-10) (OR=1.09, 95 % CI 1.02-1.17, P=0.010), regulated on activation, C-C Motif Chemokine Ligand 5 (CCL5) (OR=1.11, 95 % CI 1.03-1.20, P=0.007) were suggestively associated with an increased risk of FS. Reverse MR analysis revealed no significant causal effect of FS on the 41 systemic inflammatory factors. No heterogeneity or horizontal pleiotropy was observed in our analysis.

CONCLUSION

This study established a causal association between 41 systemic inflammatory factors and FS, indicating that elevated levels of GROa, IP-10 and CCL5 were associated with a higher risk of FS. Further research is warranted to explore the potential of these biomarkers as early predictors and therapeutic targets for FS.

Higher body mass index increases the risk of shoulder adhesive capsulitis in young adults: a nationwide cohort study

BACKGROUND

The impact of overweight on the incidence of shoulder adhesive capsulitis (AC) has not been clearly proven. This study aimed to investigate the association between overweight and AC by age using a large-scale nationwide population-based cohort in Korea.

METHODS

We analyzed clinical data from 3,517,066 individuals older than 20 years who had undergone a National Health Insurance Service health checkup in 2009. Patients who visited a hospital or private clinic to treat shoulder pain at least three times in 1 year and were assigned a diagnostic code for AC (International Classification of Diseases,10th Revision code M75.00) were identified using claims data during a median follow-up duration of 8.3 years. Hazard ratios (HRs) and 95% confidence intervals for AC were calculated using the Cox proportional hazards model.

RESULTS

The adjusted HR for AC in the < 40 year group started to increase in overweight status and was associated with the severity of obesity (body mass index (BMI) < 18.5; 0.654 (0.613-0.697), <23; 1, <25; 1.272 (1.231-1.315), <30; 1.322 (1.281-1.364), ≥30; 1.332 (1.253-1.416)). But in the 40-64 year group and the ≥ 65 year group, there was no significant increasing trend of HR for AC according to BMI level. We conducted a subgroup analysis based on the BMI 23 for defining overweight and presence of comorbidities including diabetes and hyperlipidemia. The adjusted HR for AC was highest with overweight and comorbidities of diabetes and hyperlipidemia (diabetes; 1.528 (1.508-1.549), hyperlipidemia; 1.212 (1.199-1.226)).

CONCLUSIONS

In the young age group (20-40 years), a higher BMI level increased the HR for AC. Overweight along with diabetes or hyperlipidemia significantly increased the risk of AC.

A new perspective of frozen shoulder pathology; the interplay between the brain and the immune system

Frozen shoulder (FS), also known as adhesive capsulitis of the shoulder (FS), is a fibrotic inflammatory process of unknown etiology whose main symptoms are pain, stiffness and the loss of joint mobility. These symptoms may be associated with pathologies such as diabetes, Dupuytren's syndrome and the prevalence of today's sedentary lifestyle. This literature review provides an overview of the epidemiology and pathogenesis of this pathology, as well as the mechanisms of lowgrade chronic inflammation and infection, insulin resistance, and omics-science associated with it. We also propose a new hypothesis related to the possibility that the GABAergic system could play a decisive role in the development of frozen shoulder and that therefore diabetes type 1, endocrinological autoimmune disorders and frozen shoulder are connected by the same pathophysiological mechanisms. If that is true, the combined presence of psycho-emotional stress factors and pathogenic immune challenges could be the main causes of frozen shoulder syndrome. Finally, we propose a series of possible intervention strategies based on a multifactorial etiological and mechanistic concept.

The Risk of Shoulder Adhesive Capsulitis in Individuals with Prediabetes and Type 2 Diabetes Mellitus: A Longitudinal Nationwide Population-Based Study

BACKGRUOUND

This study aimed to investigate the association between type 2 diabetes mellitus (T2DM) and shoulder adhesive capsulitis (AC) using a large-scale, nationwide, population-based cohort in the Republic of Korea.

METHODS

A total of 3,471,745 subjects aged over 20 years who underwent a National Health Insurance Service medical checkup between 2009 and 2010 were included in this study, and followed from the date of their medical checkup to the end of 2018. Subjects were classified into the following four groups based on the presence of dysglycemia and history of diabetes medication: normal, prediabetes, newly diagnosed T2DM (new-T2DM), and T2DM (claim history for antidiabetic medication). The endpoint was new-onset AC during follow-up. The incidence rates (IRs) in 1,000 person-years and hazard ratios (HRs) of AC for each group were analyzed using Cox proportional hazard regression models.

RESULTS

The IRs of AC were 9.453 (normal), 11.912 (prediabetes), 14.933 (new-T2DM), and 24.3761 (T2DM). The adjusted HRs of AC in the prediabetes, new-T2DM, and T2DM groups were 1.084 (95% confidence interval [CI], 1.075 to 1.094), 1.312 (95% CI, 1.287 to 1.337), and 1.473 (95% CI, 1.452 to 1.494) compared to the normal group, respectively. This secular trend of the HRs of AC according to T2DM status was statistically significant (P<0.0001).

CONCLUSION

This large-scale, longitudinal, nationwide, population-based cohort study of 3,471,745 subjects confirmed that the risk of AC increases in prediabetic subjects and is associated with T2DM status.

Prognostic factors associated with improvements in patient-reported outcomes in idiopathic adhesive capsulitis

Background

The purpose of this study was to identify prognostic factors that are associated with improvements in patient-reported outcomes measures (PROMs) related to upper extremity function and pain in those suffering from idiopathic adhesive capsulitis.

Methods

All patients treated conservatively for primary idiopathic adhesive capsulitis were identified from our institutional database between 2019 and 2021. Exclusion criteria included any patients treated surgically, follow-up less than one year, or incomplete survey results. PROMs including Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity Computer Adaptive Test Version 2.0 (P-UE), Pain Interference (P-Interference), Pain Intensity (P-Intensity), and visual analog scale (VAS) pain scores. They were obtained at initial consultation and at one year to assess patient-perceived impact of their condition. Multiple linear and multivariable logistic regressions were performed to identify factors associated with improvement in patient-perceived pain and shoulder function using final PROM scores and difference in PROM scores from initial consultation. An independent t-test was used to compare baseline and one-year minimum follow-up PROMs. Odds ratios and their 95% confidence intervals were calculated for each factor; a P value of < .05 was considered statistically significant.

Results

A total of 56 patients (40 females and 16 males) were enrolled in the study with an average age of 54.7 ± 7.7 years. A significant improvement (P < .001) was demonstrated at one-year minimum outcomes for P-UE, P-Interference, P-Intensity, and VAS scores. With respect to comorbid conditions, hypothyroidism [P-UE (β: 9.57, P = .006)] was associated with greater improvements in PROMs, while hyperlipidemia [P-UE (β: -4.13, P = .01) and P-Intensity (β: 2.40, P = .02)] and anxiety [P-UE (β: -4.13, P = .03)] were associated with poorer reported changes in PROMs. Female sex [P-UE (β: 4.03, P = .007) and P-Interference (β: -2.65, P = .04)] and employment in manual labor professions [P-Interference (β: -3.07, P = .01), P-Intensity (β: -2.92, P = .006), and VAS (β: -0.66, P = .03)] were associated with significantly better patient-perceived outcomes. Hispanic heritage was associated with higher reported changes of P-Intensity (β: 8.45, P = .004) and VAS (β: 2.65, P = .002).

Conclusion

Patient-perceived improvements in PROMIS score during the natural history of adhesive capsulitis are likely multifactorial, with anxiety, hyperlipidemia, increased body mass index, and Hispanic heritage associated with reduced improvement in PROMIS scores.

Minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) of upper extremity PROMIS scores in idiopathic adhesive capsulitis

INTRODUCTION

The purpose of this study is to calculate the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) of Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity Computer Adaptive Testing v2.0 (UE), Pain Interference (P-Interference), and Pain Intensity (P-Intensity) in patients treated nonoperatively for idiopathic adhesive capsulitis (IAC).

METHODS

The anchor-based MCID, SCB, and PASS were calculated as the change in PROMIS scores representing the optimal cutoff for a ROC curve with an area under the curve (AUC) analysis. The distribution-based MCID was calculated as a range between the average standard error of measurement multiplied by two different constants: 1 and 2.77. Effect sizes and standardized response means (SRM) were calculated to assess the responsiveness of each PROMIS instrument while regression analyses were performed to identify factors associated with achieving these thresholds.

RESULTS

This study enrolled 115 patients. The anchor-based MCID for PROMIS UE, P-Interference, and P-Intensity was 5.11, 4.16, and 8.16, respectively. The respective SCB was 8.44, 6.65, and 10.05. The respective PASS was 8.47, 7.01, and 10.41. The odds of achieving MCID values in adhesive capsulitis were negatively affected by gender (male), higher forward elevation at the time of presentation, higher pain scores (P-Interference), need for ≥ 2 corticosteroid injections, and a concomitant diagnosis of diabetes.

CONCLUSION

The MCID, SCB, and PASS parameters for PROMIS scores can be utilized to determine the clinical meaningfulness of patient-reported improvements in these instruments during the nonoperative treatment and as a research tool to compare the efficacy of new treatments for adhesive capsulitis.

LEVEL OF EVIDENCE

Level III, basic science study, validation of outcome instruments. Key points • This is the first study to calculate the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for the Patient-Reported Outcome Measurement Information System (PROMIS) Upper Extremity and Pain instruments in patients with idiopathic adhesive capsulitis (IAC) of the shoulder.• This study determined the impact of symptom severity, demographics, and comorbidities on achieving the MCID, SCB, and PASS for PROMIS instruments in IAC patients treated nonoperatively.

Diabetes as a risk factor for the onset of frozen shoulder: a systematic review and meta-analysis

OBJECTIVE

Summarise longitudinal observational studies to determine whether diabetes (types 1 and 2) is a risk factor for frozen shoulder.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, AMED, PsycINFO, Web of Science Core Collection, CINAHL, Epistemonikos, Trip, PEDro, OpenGrey and The Grey Literature Report were searched on January 2019 and updated in June 2021. Reference screening and emailing professional contacts were also used.

ELIGIBILITY CRITERIA

Longitudinal observational studies that estimated the association between diabetes and developing frozen shoulder.

DATA EXTRACTION AND SYNTHESIS

Data extraction was completed by one reviewer and independently checked by another using a predefined extraction sheet. Risk of bias was judged using the Quality In Prognosis Studies tool. For studies providing sufficient data, random-effects meta-analysis was used to derive summary estimates of the association between diabetes and the onset of frozen shoulder.

RESULTS

A meta-analysis of six case-control studies including 5388 people estimated the odds of developing frozen shoulder for people with diabetes to be 3.69 (95% CI 2.99 to 4.56) times the odds for people without diabetes. Two cohort studies were identified, both suggesting diabetes was associated with frozen shoulder, with HRs of 1.32 (95% CI 1.22 to 1.42) and 1.67 (95% CI 1.46 to 1.91). Risk of bias was judged as high in seven studies and moderate in one study.

CONCLUSION

People with diabetes are more likely to develop frozen shoulder. Risk of unmeasured confounding was the main limitation of this systematic review. High-quality studies are needed to confirm the strength of, and understand reasons for, the association.

PROSPERO REGISTRATION NUMBER

CRD42019122963.

Biopsychosocial Approach in Identifying Risk Factors of Kinesiophobia in Persons with Subacromial Pain Syndrome and Developing a Clinical Prediction Tool

Introduction

Although the negative effects of kinesiophobia on functional status in subacromial pain syndrome (SAPS) patients are clearly demonstrated, no study examines the risk factors of kinesiophobia in individuals with SAPS from a biopsychosocial perspective. The present study aims to determine the risk factors of kinesiophobia in individuals with SAPS using a biopsychosocial approach. This study also aims to explore the compounding effects of multiple associative risk factors by developing a clinical prediction tool to identify SAPS patients at higher risk for kinesiophobia.

Materials and methods

This cross-sectional study included 549 patients who were diagnosed with SAPS. The Tampa-Scale of Kinesiophobia (TSK) was used to assess kinesiophobia. Visual analog scale (VAS), The Shoulder Pain and Disability Index (SPADI), Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, the presence of metabolic syndrome, using any non-steroidal anti-inflammatory drugs, Pain Catastrophizing Scale (PCS), Illness Perception Questionnaire-revised (IPQ-R), Hospital Anxiety and Depression Scale (HADS), behavioral pattern of the patient, sociodemographic characteristics, and treatment expectancy were outcome measures.

Results

Thirteen significant risk factors of having kinesiophobia were: VASat rest (≥ 5.2), VASduring activity (≥ 7.1), DASH (≥ 72.1), presence of metabolic syndrome, PCShelplessness (≥ 16.1), IPQ-Rpersonal control (≤ 17.1), IPQ-Rtreatment control (≤ 16.3), HADSdepression (≥ 7.9), avoidance behavior type, being female, educational level (≤ high school), average hours of sleep (≤ 6.8), and treatment expectancy (≤ 6.6). The presence of seven or more risk factors increased the probability of having high level of kinesiophobia from 34.3 to 51%.

Conclusions

It seems necessary to address these factors, increase awareness of health practitioners and individuals.

Level of evidence

Level IV.

Frozen shoulder

Frozen shoulder is a common debilitating disorder characterized by shoulder pain and progressive loss of shoulder movement. Frozen shoulder is frequently associated with other systemic conditions or occurs following periods of immobilization, and has a protracted clinical course, which can be frustrating for patients as well as health-care professionals. Frozen shoulder is characterized by fibroproliferative tissue fibrosis, whereby fibroblasts, producing predominantly type I and type III collagen, transform into myofibroblasts (a smooth muscle phenotype), which is accompanied by inflammation, neoangiogenesis and neoinnervation, resulting in shoulder capsular fibrotic contractures and the associated clinical stiffness. Diagnosis is heavily based on physical examination and can be difficult depending on the stage of disease or if concomitant shoulder pathology is present. Management consists of physiotherapy, therapeutic modalities such as steroid injections, anti-inflammatory medications, hydrodilation and surgical interventions; however, their effectiveness remains unclear. Facilitating translational science should aid in development of novel therapies to improve outcomes among individuals with this debilitating condition.

Evaluating whole-genome expression differences in idiopathic and diabetic adhesive capsulitis

BACKGROUND

Diabetic patients have a greater incidence of adhesive capsulitis (AC) and a more protracted disease course than patients with idiopathic AC. The purpose of this study was to compare gene expression differences between AC with diabetes mellitus and AC without diabetes mellitus.

METHODS

Shoulder capsule samples were prospectively obtained from diabetic or nondiabetic patients who presented with shoulder dysfunction and underwent arthroscopy (N = 16). Shoulder samples of AC with and without diabetes (n = 8) were compared with normal shoulder samples with and without diabetes as the control group (n = 8). Shoulder capsule samples were subjected to whole-transcriptome RNA sequencing, and differential expression was analyzed with EdgeR. Only genes with a false discovery rate < 5% were included for further functional enrichment analysis.

RESULTS

The sample population had a mean age of 47 years (range, 24-62 years), and the mean hemoglobin A_1c level for nondiabetic and diabetic patients was 5.18% and 8.71%, respectively. RNA-sequencing analysis revealed that 66 genes were differentially expressed between diabetic patients and nondiabetic patients with AC whereas only 3 genes were differentially expressed when control patients with and without diabetes were compared. Furthermore, 286 genes were differentially expressed in idiopathic AC patients, and 61 genes were differentially expressed in diabetic AC patients. On gene clustering analysis, idiopathic AC was enriched with multiple structural and muscle-related pathways, such as muscle filament sliding, whereas diabetic AC included a greater number of hormonal and inflammatory signaling pathways, such as cellular response to corticotropin-releasing factor.

CONCLUSIONS

Whole-transcriptome expression profiles demonstrate a fundamentally different underlying pathophysiology when comparing diabetic AC with idiopathic AC, suggesting that these conditions are distinct clinical entities. The new genes expressed explain the differences in the disease course and suggest new therapeutic targets that may lead to different treatment paradigms in these 2 subsets.

Effects of comorbidities on the outcomes of manipulation under anesthesia for primary stiff shoulder

BACKGROUND

Studies on the effects of manipulation under anesthesia (MUA) for primary stiff shoulder when different comorbidities are present are lacking. Our aim was to assess how comorbidities influence the recovery speed and clinical outcomes after MUA.

METHODS

Between April 2013 and September 2018, 281 consecutive primary stiff shoulders in the frozen phase treated with MUA were included in this study. We investigated the comorbidities of patients and divided them into the control (n = 203), diabetes mellitus (DM) (n = 32), hyperlipidemia (n = 26), and thyroid disorder (n = 20) groups. The range of motion (ROM) and clinical scores for each group before MUA and 1 week, 6 weeks, and 3 months after MUA were comparatively analyzed. We identified the ROM recovery time after MUA and the responsiveness to MUA. Then, subjects were subdivided into early and late recovery groups based on their recovery time and into successful and nonsuccessful MUA groups based on their responsiveness to MUA.

RESULTS

Significant improvements in ROM and clinical scores at 3 months after MUA were observed in all groups. Significant differences in ROM among the 4 groups were also observed during follow-up (P < .05). The DM group had significantly lower ROM values, even at 3 months after MUA, compared with the control group. The ROM recovery speed after MUA was slowest in the DM group, followed by the thyroid disorder, hyperlipidemia, and control groups. Most (90.6%) of the DM group experienced late recovery. The proportion of nonsuccessful MUA was higher in the DM and thyroid disorder groups than that in the control and hyperlipidemia groups (P = .004). During follow-up, there were no differences among groups regarding the visual analog scale, University of California at Los Angeles shoulder, and Constant scores.

CONCLUSION

The ROM recovery speed and responsiveness to MUA for primary stiff shoulder were poorer for the DM and thyroid disorder groups than for the control group. In particular, compared with any other disease, outcomes were poorer when the comorbidity was DM. If patients have comorbidities, then they should be informed before MUA that the comorbidity could affect the outcomes of treatment.

The puzzling pathophysiology of frozen shoulders - a scoping review

Purpose

The pathophysiology of frozen shoulders is a complex and multifactorial process. The purpose of this review is to scope the currently available knowledge of the pathophysiology of frozen shoulders.

Methods

A systematic search was conducted in Medline, Embase and the Cochrane library. Original articles published between 1994 and October 2020 with a substantial focus on the pathophysiology of frozen shoulders were included.

Results

Out of 827 records, 48 original articles were included for the qualitative synthesis of this review. Glenohumeral capsular biopsies were reported in 30 studies. Fifteen studies investigated were classified as association studies. Three studies investigated the pathophysiology in an animal studies. A state of low grade inflammation, as is associated with diabetes, cardiovascular disease and thyroid disorders, predisposes for the development of frozen shoulder. An early immune response with elevated levels of alarmins and binding to the receptor of advance glycation end products is present at the start of the cascade. Inflammatory cytokines, of which transforming growth factor-β1 has a prominent role, together with mechanical stress stimulates Fibroblast proliferation and differentiation into myofibroblasts. This leads to an imbalance of extracellular matrix turnover resulting in a stiff and thickened glenohumeral capsule with abundance of type III collagen.

Conclusion

This scoping review outlines the complexity of the pathophysiology of frozen shoulder. A comprehensive overview with background information on pathophysiologic mechanisms is given. Leads are provided to progress with research for clinically important prognostic markers and in search for future interventions.

Level of evidence

Level V.

Association between fasting glucose levels and adhesive capsulitis in a normoglycemic population: a case-control study

BACKGROUND

Hyperglycemia is the most commonly cited risk factor for adhesive capsulitis. However, no study has established whether fasting glucose levels within the normoglycemic range are associated with idiopathic adhesive capsulitis (IAC). This study hypothesized that increments of fasting glucose levels within the normoglycemic range would be linked to IAC. This study investigated any association between normoglycemic fasting glucose levels and IAC.

METHODS

This case-control study comprised a group of 151 patients with IAC without intrinsic shoulder lesions, extrinsic causes, or known metabolic risk factors such as diabetes, dyslipidemia, and thyroid dysfunction. The control group comprised 453 age- and sex-matched persons seeking general check-ups at the authors' health promotion center during the same period as the case group. Control subjects had normal shoulder function, no previous diagnosis of adhesive capsulitis or of metabolic disease, and no history of trauma or of shoulder surgery. The studied variables were body mass index, serum lipid profiles, thyroid hormone levels, fasting glucose levels, glycosylated hemoglobin A1c, and high-sensitivity C-reactive protein. Fasting glucose levels were studied as scale data and categorical data (<85, 85-89, 90-94, and 95-99 mg/dL). Multivariable conditional logistic regression analysis evaluated the matched sets of subjects. Odds ratios and 95% confidence intervals were determined for various potentially associated factors.

RESULTS

Fasting glucose level, hypercholesterolemia, and high-sensitivity C-reactive protein were significantly associated with IAC (P ≤ .030). Fasting glucose levels in the <85 mg/dL quartile were significantly negatively associated with IAC (P ≤ .001). In contrast, fasting glucose levels in the 90-94 mg/dL quartile or higher were significantly positively associated with IAC (P ≤ .034).

CONCLUSION

IAC is positively associated with fasting glucose levels of 90-99 mg/dL, which are currently considered normoglycemic.

Association Between High-Sensitivity C-Reactive Protein and Idiopathic Adhesive Capsulitis

BACKGROUND

Chronic inflammation is implicated in the development of idiopathic adhesive capsulitis (IAC), whose association with high-sensitivity C-reactive protein (CRP), an inflammation marker, is undetermined. This study's purposes were to investigate the association between high-sensitivity CRP levels and IAC and to determine the metabolic factors associated with high-sensitivity CRP.

METHODS

This case-control study examined a group of 202 patients with IAC and without intrinsic shoulder lesions or extrinsic causes and a control group of 606 age and sex-matched persons seeking general check-ups at our health promotion center during the same period as the case group. Control subjects had normal shoulder function and no previously diagnosed adhesive capsulitis; no medication for diabetes, dyslipidemia, and thyroid abnormalities; and no history of trauma or of shoulder surgery. The studied variables were body mass index; diabetes; thyroid abnormalities; dyslipidemias; triglyceride/high-density lipoprotein (TG/HDL) >3.5; serum levels of thyroid hormone, fasting glucose, and glycosylated hemoglobin A1c (HbA1c); and high-sensitivity CRP >1.0 mg/L. Multivariable conditional logistic regression analysis evaluated the matched sets of subjects. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for the studied variables possibly affecting IAC.

RESULTS

Serum high-sensitivity CRP >1.0 mg/L was significantly associated with IAC (OR, 2.47 [95% CI, 1.65 to 3.70]) after adjusting for diabetes, fasting glucose level, HbA1c, dyslipidemia, TG/HDL >3.5, and thyroid-stimulating hormone (p ≤ 0.031). Diabetes (OR, 1.71 [95% CI, 1.09 to 3.33]), fasting glucose level (OR, 1.54 [95% CI, 1.12 to 2.12]), HbA1c (OR, 2.00 [95% CI, 1.25 to 3.22]), hypertriglyceridemia (OR, 1.70 [95% CI, 1.03 to 3.41]), hypo-high-density lipoproteinemia (OR, 1.98 [95% CI, 1.04 to 3.79]), and TG/HDL >3.5 (OR, 1.37 [95% CI, 1.06 to 1.88]) were significantly associated with high-sensitivity CRP >1.0 mg/L in patients with IAC (p ≤ 0.039).

CONCLUSIONS

Serum high-sensitivity CRP >1.0 mg/L is an independent associated marker for IAC. Dyslipidemia, insulin resistance, and hyperglycemia, which are recognized factors associated with IAC, are also associated with high-sensitivity CRP >1.0 mg/L in these patients, supporting the interaction of chronic systemic inflammation in IAC.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Is frozen shoulder completely resolved at 2 years after the onset of disease?

BACKGROUND

Although numerous studies have suggested that frozen shoulder (FS) is a self-limiting disease with most patients recovering within 2 years, its long-term outcome is still controversial. The aims of this study were to evaluate the clinical outcomes after conservative treatment for FS and to determine the predictors of its clinical outcome.

METHODS

This study included 234 shoulders of 215 patients who received conservative treatment for FS. The mean follow-up period was 41.8 months (range 27-117 months). Initial evaluation included demographics, detailed medical history, and clinical assessments of shoulder status. Questionnaires, which included the Visual Analogue Scale (VAS) pain score, American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV) and satisfaction grading for the current shoulder status were assessed at the final follow-up.

RESULTS

The mean VAS pain score, ASES score, and SSV significantly improved from 6.7, 37.0, and 40.1% at the time of initial evaluation to 1.5, 87.6, and 85.0% at the final follow-up evaluation (all p < 0.001). According to satisfaction grading, the shoulder status at the final follow-up was very satisfied in 101 shoulders (43.2%), satisfied in 68 (29.1%), fair in 37 (15.8%), unsatisfied in 20 (8.5%), and very unsatisfied in 8 (3.4%). Univariate analysis revealed that gender, diabetes, simultaneous bilateral involvement, overall bilateral involvement and duration of symptoms were associated with clinical outcomes at the final follow-up. Multivariate analysis revealed that duration of symptoms (p = 0.002) was an independent risk factor for unsuccessful outcome.

CONCLUSIONS

At the mean follow-up period of 41.8 months, 72.3% of patients revealed subjective satisfaction for the current shoulder status. Duration of symptoms was an independent risk factor for poor prognosis.

Short-Term Outcome Predictors in Patients With Primary Adhesive Capsulitis Treated With Ultrasound-Guided Hydrodilatation With Corticosteroids

OBJECTIVE

Glenohumeral joint hydrodilatation with corticosteroids has been proposed as an effective secondary therapeutic procedure for primary adhesive capsulitis. However, little is known about which subgroup of patients would benefit from this procedure. This study aimed to identify covariates associated with improved prognosis in patients receiving ultrasound-guided hydrodilatation with corticosteroid injection.

DESIGN

This was a cohort study. Data on baseline demographic characteristics, disease status, past medical conditions, and initial ultrasonographic findings were collected. Linear and logistic regression analyses were performed to determine the prognostic factors associated with better clinical outcomes.

RESULTS

Fifty-three patients (54 shoulders) were included. Linear regression analysis showed that coracohumeral ligament thickness of less than 3 mm, use of analgesics before hydrodilatation, and female sex were associated with good improvement in the Shoulder Pain and Disability Index score. Multivariate logistic regression analysis showed that coracohumeral ligament thickness of less than 3 mm on ultrasound was associated with a strong tendency (P = 0.054) of reaching the minimal detectable change. In addition, capsule rupture did not play a role in determining the clinical efficacy of hydrodilatation.

CONCLUSIONS

In patients with primary adhesive capsulitis, coracohumeral ligament thickness of less than 3 mm is correlated with greater short-term improvement in the Shoulder Pain and Disability Index score after ultrasound-guided hydrodilatation with steroid injection is performed.

Is there an association between metabolic syndrome and rotator cuff-related shoulder pain? A systematic review

Objectives

Rotator cuff-related shoulder pain (RCRSP) is a common upper limb complaint. It has been suggested that this condition is more common among people with cardiometabolic risk factors. This systematic review has synthesised evidence from case–control, cross-sectional and cohort studies on the association between metabolic syndrome (MetS) and RCRSP.

Design and data sources

Five medical databases (MEDLINE, EMBASE, SCOPUS, CINAHL and AMED) and reference checking methods were used to identify all relevant English articles that considered MetS and RCRSP. Studies were appraised using the Newcastle-Ottawa Scale (NOS). Two reviewers performed critical appraisal and data extraction. Narrative synthesis was performed via content analysis of statistically significant associations.

Results

Three cross-sectional, two case–control and one cohort study met the inclusion criteria, providing a total of 1187 individuals with RCRSP. Heterogeneity in methodology and RCRSP or MetS definition precluded a meaningful meta-analysis. Four of the included studies identified associations between the prevalence of MetS and RCRSP. Studies consistently identified independent cardiometabolic risk factors associated with RCRSP. All studies were level III evidence.

Summary and conclusion

The low-moderate quality evidence included in this review suggests an association between MetS and RCRSP. Most studies demonstrated moderate quality on appraisal. The direction of association and cardiometabolic factors influencing should be investigated by longitudinal and treatment studies. These preliminary conclusions and clinical utility should be treated with caution due to limitations of the evidence base.

The impact of pre-existing shoulder diseases and traumatic injuries of the shoulder on adhesive capsulitis in adult population: A population-based nested case-control study

Adhesive capsulitis (AC) is a common chronic disorder for adult patients; however, whether a history of pre-existing shoulder diseases may affect the development of AC is still not fully understood. We aimed to investigate the incidence and prevalence of AC and to assess the association of pre-existing shoulder diseases and traumatic injuries of the shoulder with the development of AC in adults.This retrospective population-based cohort and nested case-control study used data from the National Health Institute Research Database of Taiwan. A total of 24,414 patients aged 20 years or older and with a diagnosis of AC were identified between 2000 and 2013. We calculated the incidence of AC for each year during the study period. In addition, these AC patients were matched with controls (n = 97,656) in a ratio of 1:4 based on age, gender, and index date. Univariate and multivariate logistic regression models were performed to identify variables associated with AC.Females and patients aged 50 to 69 years had higher age-gender standardized incidence and prevalence of AC than their counterparts. Multivariate analyses showed that after adjusting for relevant covariates, pre-existing shoulder diseases of calcific tendinitis (odds ratio [OR] = 8.74, 95% confidence interval [CI] = 5.66-13.5), biceps tendinitis (OR = 7.93, 95% CI = 5.33-11.79), rotator cuff syndrome (OR = 6, 95% CI = 5.26-6.85), osteoarthritis (OR = 4.27, 95% CI = 3.44-5.3), and impingement syndrome (OR = 3.13, 95% CI = 2.64-3.71), as well as fracture (OR = 4.51, 95% CI = 3.82-5.34) and dislocation (OR = 3.57, 95% CI = 2.35-5.45) of the shoulder were significantly associated with AC risk.Higher odds of AC were observed among patients with pre-existing shoulder conditions. This study highlights the need to consider differences in AC risk among patients with various types of shoulder diseases and traumatic injuries of the shoulder.

Genetic variants involved in extracellular matrix homeostasis play a role in the susceptibility to frozen shoulder: A case-control study

Frozen shoulder is a condition of loss of active and passive motion as result of inflammatory contracture and fibrosis of the joint capsule. We hypothesize that genetic variants in genes involved in these processes such as genes that play a role in extracellular matrix homeostasis (collagens, glycoproteins, genes involved in TGFβ signaling, and metalloproteinases and its inhibitors) may contribute to the susceptibility to frozen shoulder. We evaluated eighteen SNPs of genes involved in extracellular matrix homeostasis in 186 cases (N_females  = 114; N_males  = 72) of frozen shoulder and 600 age-matched controls (N_females  = 308; N_males  = 292). Multivariate logistic regressions were carried out with age, gender, genetic ancestry, and common comorbidities as covariates. Carriers of the C allele of MMP13 rs2252070 and G/G MMP9 (rs17576 A>G/rs17577 G>A) haplotype may have an increased risk of frozen shoulder (p = 0.002, OR = 1.64, 95%CI = 1.20-2.26, and p = 0.046, OR = 1.40, 95%CI = 1.01-1.95, respectively), especially in females (p = 0.005, OR = 1.91, 95%CI = 1.22-2.99, and p = 0.046, OR = 1.59, 95%CI = 1.01-2.51, respectively). In females, the G allele of MMP9 rs17576 tended to contribute to the susceptibility to the studied disease (p = 0.05, OR = 1.51, 95%CI = 0.97-2.33). In contrast, the presence of the C allele of TGFB1 rs1800470 seems to be associated with a reduced risk (p = 0.04, OR = 0.47, 95%CI = 0.23-0.96) while the GG-genotype of TGFBR1 rs1590 was associated with increased risk (p = 0.027, OR = 4.11, 95%CI = 1.17-14.38) to frozen shoulder development in males. Thus, we identified genetic variants that were independent risk factors that can aid in the risk assessment of frozen shoulder reinforcing the involvement of MMP and TGFβ signaling in disease development. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Prevalence and Impact of Diabetes Mellitus on the Frozen Shoulder

OBJECTIVES

The objective of this study was to estimate the prevalence of undiagnosed diabetes mellitus in patients with newly diagnosed frozen shoulder (FS) and study whether diabetes mellitus increases the severity of FS disease.

METHODS

Patients with newly diagnosed FS were consecutively included in this case-control study. Patients who were not already diagnosed as having diabetes mellitus were invited to be tested with the hemoglobin A1c blood sample test. The study population was compared with a control group, consisting of five individuals from the general population matched on age and sex. The passive range of motion, Oxford Shoulder Score, and visual analog scale (VAS) for average and maximum daily pain was recorded for all of the patients in the study group.

RESULTS

A total of 235 patients were included, 34 (14%) of whom were diagnosed as having diabetes mellitus before the examination. Of the remaining 201 patients, 122 (61%) agreed to be tested for diabetes mellitus. None of the tested patients had undiagnosed diabetes mellitus. This was not significantly different from the prevalence in the matched control population (P = 0.09). There was no difference between patients with and without diabetes mellitus in average daily VAS (P = 0.46) nor maximum daily VAS (P = 0.44). The Oxford Shoulder Score was similar in the two groups (P = 0.23) as was the range of motion.

CONCLUSIONS

The prevalence of undiagnosed diabetes mellitus is low in patients with FS and does not differ from the general population. Diabetes mellitus does not seem to affect patients' perceived severity of an FS.

Adhesive capsulitis: An age related symptom of metabolic syndrome and chronic low-grade inflammation?

Adhesive capsulitis (AC) is very poorly understood, particularly it's underlying etiology. Obesity and metabolic syndrome, which are strongly associated with chronic low grade inflammation, are becoming increasingly understood to underlie a raft of morbid states including upper limb pain syndromes, diabetes (DM), cardiovascular disease (CVD), cancer and central nervous system dysfunction and degeneration. Notwithstanding age, two of the strongest established risk factors for AC are DM and CVD. The hypothesis argues that similar to DM and CVD, the inflammation and capsular fibrosis seen in AC is precipitated by metabolic syndrome and chronic low grade inflammation. These pathophysiological mechanisms are highly likely to be perpetuated by upregulation of pro-inflammatory cytokine production, sympathetic dominance of autonomic balance, and neuro-immune activation. The hypothesis predicts and describes how these processes may etiologically underpin and induce each sub-classification of AC. An improved understanding of the etiology of AC may lead to more accurate diagnosis, improved management, treatment outcomes, and reduce or prevent pain, disability and suffering associated with the disease. The paper follows on with a discussion of similarities between the pathophysiology of AC to general systemic inflammatory control mechanisms whereby connective tissue (CT) fibrosis is induced as a storage depot for leukocytes and chronic inflammatory cells. The potential role of hyaluronic acid (HA), the primary component of the extracellular matrix (ECM) and CT, in the pathophysiology of AC is also discussed with potential treatment implications. Lastly, a biochemical link between physical and mental health through the ECM is described and the concept of a periventricular-limbic central driver of CT dysfunction is introduced.