A Comprehensive View of Frozen Shoulder: A Mystery Syndrome

Targeting the Sweet Spot: A Systematic Review With Meta-Analysis of Anterior Versus Posterior Glenohumeral Joint Injections for Adhesive Capsulitis

OBJECTIVE

To compare clinical outcomes following steroid injections using the anterior and posterior approaches.

DESIGN

Systematic review with meta-analysis.

SETTING

Embase, Web of Science, and Cochrane Center Register of Controlled Trials were searched for randomized control trials (RCTs) and prospective comparative studies.

PATIENTS

Patients with adhesive capsulitis.

INTERVENTIONS

Glenohumeral steroid injections using either anterior or posterior approach.

MAIN OUTCOME MEASURES

Pain visual analog scale (VAS) and shoulder range of motion (ROM) at 12 weeks, accuracy, and adverse events. Standardized mean difference (SMD) for VAS and weighted mean difference (WMD) for ROMs.

RESULTS

We identified 6 RCTs and one prospective comparative study with a total of 468 patients. While there was no difference in pain VAS at 12 weeks between the 2 approaches (SMD, -0.86; 95% CI, -1.76 to 0.04), the anterior approach resulted in greater improvements in external rotation (WMD, 8.08; 95% CI, 0.79-15.38) and abduction (WMD, 6.76; 95% CI, 3.05-10.48) compared with the posterior approach. Subgroup analysis with RCTs that utilized steroid injection with hydrodilatation for both approaches demonstrated greater reduction in pain VAS at 12 weeks with the anterior approach (SMD, -0.52; 95% CI, -0.98 to -0.07). Overall, procedures were well tolerated without major complications.

CONCLUSIONS

While pain reduction is similar, the anterior approach may be more beneficial in restoring shoulder external rotation and abduction compared with the posterior approach at 12 weeks. Steroid injection combined with hydrodilatation may further improve pain control when performed with the anterior approach at 12 weeks.

Unveiling potential therapeutic targets for diabetes-induced frozen shoulder through Mendelian randomization analysis of the human plasma proteome

INTRODUCTION

This study aimed to assess the causal relationship between diabetes and frozen shoulder by investigating the target proteins associated with diabetes and frozen shoulder in the human plasma proteome through Mendelian randomization (MR) and to reveal the corresponding pathological mechanisms.

RESEARCH DESIGN AND METHODS

We employed the MR approach for the purposes of establishing: (1) the causal link between diabetes and frozen shoulder; (2) the plasma causal proteins associated with frozen shoulder; (3) the plasma target proteins associated with diabetes; and (4) the causal relationship between diabetes target proteins and frozen shoulder causal proteins. The MR results were validated and consolidated through colocalization analysis and protein-protein interaction network.

RESULTS

Our MR analysis demonstrated a significant causal relationship between diabetes and frozen shoulder. We found that the plasma levels of four proteins were correlated with frozen shoulder at the Bonferroni significance level (p<3.03E-5). According to colocalization analysis, parathyroid hormone-related protein (PTHLH) was moderately correlated with the genetic variance of frozen shoulder (posterior probability=0.68), while secreted frizzled-related protein 4 was highly correlated with the genetic variance of frozen shoulder (posterior probability=0.97). Additionally, nine plasma proteins were activated during diabetes-associated pathologies. Subsequent MR analysis of nine diabetic target proteins with four frozen shoulder causal proteins indicated that insulin receptor subunit alpha, interleukin-6 receptor subunit alpha, interleukin-1 receptor accessory protein, glutathione peroxidase 7, and PTHLH might contribute to the onset and progression of frozen shoulder induced by diabetes.

CONCLUSIONS

Our study identified a causal relationship between diabetes and frozen shoulder, highlighting the pathological pathways through which diabetes influences frozen shoulder.

Clinical evaluation of a patient participation assessment system for upper extremity rehabilitation exercises

In conventional and robotic rehabilitation, the patient's active participation in exercises is essential for the maximum functional output to be received from therapy. In rehabilitation exercises performed with robotic devices, the difficulty levels of therapy tasks and the device assistance are adjusted based on the patient's therapy performance to improve active participation. However, the existing therapy performance evaluation methods are based on either some specific device designs or certain therapy tasks, which limits their widespread use. In this paper, the effectiveness of a participation assessment system, which can evaluate patients' therapy performance, tiredness, and slacking independent of any device design and therapy exercise, was clinically tested on ten patients diagnosed with frozen shoulder syndrome. The patients performed exercises using the system once a week throughout their 4-week treatment period. Multiple clinical measurements and scales were employed during the clinical study to assess patients' progress and status, such as tiredness throughout the therapy process. The clinical data, along with the patient findings obtained from the participation assessment system, were statistically analyzed and compared. The findings revealed that the patients' improvements and progress during the therapy process clinically coincide with the variations in the performance evaluation results of the system, and the implemented method successfully assesses the patients' participation during the rehabilitation exercises.

Agomir-122-loaded nanoparticles coated with cell membrane of activated fibroblasts to treat frozen shoulder based on homologous targeting

As a common musculoskeletal disorder, frozen shoulder is characterized by thickened joint capsule and limited range of motion, affecting 2-5% of the general population and more than 20% of patients with diabetes mellitus. Pathologically, joint capsule fibrosis resulting from fibroblast activation is the key event. The activated fibroblasts are proliferative and contractive, producing excessive collagen. Albeit high prevalence, effective anti-fibrosis modalities, especially fibroblast-targeting therapies, are still lacking. In this study, microRNA-122 was first identified from sequencing data as a potential therapeutic agent to antagonize fibroblast activation. Then, Agomir-122, an analog of microRNA-122, was loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (Agomir-122@NP), a carrier with excellent biocompatibility for the agent delivery. Moreover, relying on the homologous targeting effect, we coated Agomir-122@NP with the cell membrane derived from activated fibroblasts (Agomir-122@MNP), with an attempt to inhibit the proliferation, contraction, and collagen production of abnormally activated fibroblasts. After confirming the targeting effect of Agomir-122@MNP on activated fibroblasts in vitro, we proved that Agomir-122@MNP effectively curtailed fibroblasts activation, ameliorated joint capsule fibrosis, and restored range of motion in mouse models both prophylactically and therapeutically. Overall, an effective targeted delivery method was developed with promising translational value against frozen shoulder.

Artificial intelligence in diagnosing upper limb musculoskeletal disorders: a systematic review and meta-analysis of diagnostic tests

Purpose

The integration of artificial intelligence (AI) in radiology has revolutionized diagnostics, optimizing precision and decision-making. Specifically in musculoskeletal imaging, AI tools can improve accuracy for upper extremity pathologies. This study aimed to assess the diagnostic performance of AI models in detecting musculoskeletal pathologies of the upper extremity using different imaging modalities.

Methods

A meta-analysis was conducted, involving searches on MEDLINE/PubMed, SCOPUS, Cochrane Library, Lilacs, and SciELO. The quality of the studies was assessed using the QUADAS-2 tool. Diagnostic accuracy measures including sensitivity, specificity, diagnostic odds ratio (DOR), positive and negative likelihood ratios (PLR, NLR), area under the curve (AUC), and summary receiver operating characteristic were pooled using a random-effects model. Heterogeneity and subgroup analyses were also included. All statistical analyses and plots were performed using the R software package.

Results

Thirteen models from ten articles were analyzed. The sensitivity and specificity of the AI models to detect musculoskeletal conditions in the upper extremity were 0.926 (95% CI: 0.900; 0.945) and 0.908 (95% CI: 0.810; 0.958). The PLR, NLR, lnDOR, and the AUC estimates were found to be 19.18 (95% CI: 8.90; 29.34), 0.11 (95% CI: 0.18; 0.46), 4.62 (95% CI: 4.02; 5.22) with a (P < 0.001), and 95%, respectively.

Conclusion

The AI models exhibited strong univariate and bivariate performance in detecting both positive and negative cases within the analyzed dataset of musculoskeletal pathologies in the upper extremity.

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.

Amniotic Fluid Proteomics Analysis and In Vitro Validation to Identify Potential Biomarkers of Preterm Birth

This study aimed to investigate the regulation of amniotic fibroblast (AFC) function by vitamin K-dependent protein Z (PROZ) during preterm birth (PTB) and its potential role in adverse pregnancy outcomes. Proteomic samples were collected from amniotic fluid in the second trimester, and AFC were isolated from the amniotic membrane and cultured in vitro. The expression of extracellular and intracellular PROZ in AFC was modulated, and their biological properties and functions were evaluated. Clinical analysis revealed a significant upregulation of PROZ expression in amniotic fluid from preterm pregnant women. In vitro experiments demonstrated that PROZ stimulated AFC migration, enhanced their proliferative capacity, and reduced collagen secretion. Overexpression of PROZ further enhanced cell migration and proliferation, while knockdown of PROZ had the opposite effect. PROZ plays a crucial role in promoting the proliferation and migration of amniotic membrane fibroblasts. Increased PROZ expression in amniotic fluid is associated with the occurrence of PTB. These findings shed light on the potential involvement of PROZ in adverse pregnancy outcomes and provide a basis for further research on its regulatory mechanisms during PTB.

Additional intraoperative subpectoral plane block vs conventional pain control: A comparison of shoulder movement in patients with mastectomy

PURPOSE

Shoulder pain is common among mastectomy patients, with limiting shoulder mobility and negatively affecting their quality of life. Pectoral nerve blocks (PECs) have demonstrated efficacy in providing postoperative analgesia. We hypothesized that these nerve blocks could improve shoulder movement in patients undergoing mastectomy.

METHODS

This prospective, randomized, double-blind controlled trial enrolled female participants diagnosed with breast cancer and scheduled for mastectomy. Participants were randomly assigned to either the conventional analgesia group or the intervention group. In the intervention group, a PECs II block was applied prior to skin closure following a mastectomy. This study's primary outcome was the assessment of shoulder movement ratios in 5 different positions (forward elevation, external rotation, arm abduction, internal rotation, and cross-body adduction), which were recorded before surgery, at 24-h, 48-h, and 72-h intervals postoperatively, with follow-up at 1 month, 2 months, 3 months, and 6 months.

RESULTS

A total of 59 participants were included in the final analysis. Patients who underwent mastectomy with PECs II block exhibited better shoulder movement in terms of external rotation and arm abduction from the early post-surgery up to 6 months postoperatively. Shoulder forward elevation also showed superior gains during the early postoperative period, with statistical significance observed after 1 month following the surgery. However, no significant differences were found between the two groups in terms of internal rotation and adduction movements of the shoulder.

CONCLUSIONS

Compared to conventional analgesia, intraoperative pectoral nerve block under direct vision enhances shoulder mobility in forward elevation, external rotation, and arm abduction after mastectomy in breast cancer patients.

The diagnostic value of physical examination tests in adhesive capsulitis: a systematic review

INTRODUCTION

Adhesive capsulitis, a condition marked by pain and stiffness of the shoulder, can have a frustrating clinical course for patients and health care professionals. Despite huge research interest, a universally accepted and used definition of clinical criteria for the diagnosis of adhesive capsulitis is currently still lacking. This systematic review aimed to identify diagnostic values for clinical examinations tests used in the diagnosis of adhesive capsulitis.

EVIDENCE ACQUISITION

A total of 5 electronic databases (PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials [CENTRAL] and PEDro) were searched for relevant studies from 2002 until October 2022 using the terms: "adhesive capsulitis AND diagnosis" and "frozen shoulder AND diagnosis." The Downs and Black Checklist (modified) was used to assess the risk of bias. The study protocol was prospectively registered at the International prospective register of systematic reviews (PROSPERO, CRD42022365993).

EVIDENCE SYNTHESIS

The initial database search identified 1799 studies, of which 9 (0.50%) were eventually included in the systematic review. Non-intrusive shoulder range of motion measurements in patients with adhesive capsulitis using the Kinect for Windows (Microsoft, Redmond, WA, USA) showed high correlation with clinical range of motion measurement. Two specific clinical tests, the affected-unaffected shoulder approach of the Coracoid Pain Test and the Distension Test in Passive External Rotation, were identified and presented excellent sensibility and specificity in the diagnosis of adhesive capsulitis, in their original study. Comparison between clinical tests was not possible due to the heterogeneity in clinical tools.

CONCLUSIONS

This systematic review identified several physical examination tests developed for the diagnosis of adhesive capsulitis but could not compare them nor advance a set of clinical diagnostic tests that are scientifically validated. Further research is warranted to obtain validation of clinical diagnosis tools for adhesive capsulitis.

Adhesive capsulitis of the shoulder is associated with an increased risk for Parkinson's disease: a population-based longitudinal follow-up study

INTRODUCTION

Previous studies have suggested a positive association between adhesive capsulitis of the shoulder (ACS) and Parkinson's disease (PD), but longitudinal data were lacking. The present population-based longitudinal follow-up study therefore investigated the risk of developing PD in patients with ACS.

METHODS

This study utilized data from Taiwan's Longitudinal Health Insurance Database 2005 (LHID 2005). We defined our ACS group as the 19,920 patients aged between 40 and 79 who had been diagnosed with ACS between 2002 and 2006. The non-ACS group consisted of an age- and sex-matched but otherwise random selection of 19,920 patients without a diagnosis of ACS. The Kaplan-Meier method was then used to examine inter-group differences in PD-free survival rates, and Cox proportional-hazard regression modeling was used to evaluate the impact of ACS on PD risk.

RESULTS

During a median follow-up period of 105 months, 242 subjects in the ACS group and 208 subjects in the non-ACS group developed PD. The adjusted hazard ratio (HR) of 1.53 (1.26-1.86) indicated that ACS patients had a significantly higher risk of developing PD than their non-ACS counterparts, regardless of sex and age. Landmark analysis that excluded PD cases detected within the first 2 years after an ACS diagnosis showed that the HR was almost unchanged, at 1.56 (1.26-1.95).

CONCLUSIONS

Patients with ACS are at a high risk of developing PD.

KEY POINTS

• This population-based study showed that adhesive capsulitis of the shoulder (ACS) is associated with a higher risk of Parkinson's disease (PD). • This study broke new ground by using a longitudinal follow-up design and a nationally representative sample. • Our findings suggest that clinicians who care for ACS patients need to be aware of this increased risk of developing PD.

Novel technique of detecting inflammatory and osseous changes in the glenohumeral joint associated with patient age and weight using FDG- and NaF-PET imaging

OBJECTIVE

The glenohumeral (GH) joint is a classic ball-and-socket joint of the shoulder subject to various pathologies including osteoarthritis (OA). Degenerative changes of the OA evident on traditional imaging are proceeded by molecular changes, which if detected early could enhance disease prevention and treatment. In this study, we use 18F-FluoroDeoxyGlucose (FDG) and 18F-sodium-fluoride (NaF)-PET/CT to investigate the effects limb laterality, age, and BMI on the inflammation and bone turnover of the GH shoulder joint.

METHODS

FDG and NaF-PET/CT scans of 41 females (mean age of 43.9 ± 14.2 years) and 45 males (mean age of 44.5 ± 13.8 years) were analyzed with a semi-quantitative technique based on predefined region of interest.

RESULTS

There was greater FDG uptake in the left side of the GH joint compared to the right in both females (left: 0.79 ± 0.17, right: 0.71 ± 0.2; P < 0.0001) and males (left: 0.76 ± 0.19, right: 0.57 ± 0.18; P < 0.0001). We also observed a strong positive association between BMI and FDG uptakes in females (left: P < 0.0001, r = 0.71, right: P < 0.0001, r = 0.58) and males (left: P < 0.0001, r = 0.56, right: P < 0.0001, r = 0.64). Association between BMI and NaF uptake were found in males as well (left: P = 0.004, r = 0.42, right: P = 0.02, r = 0.35).

CONCLUSION

Our study demonstrates the varying effect of limb laterality and BMI on FDG and NaF uptake at the GH joint. Adoption of molecular imaging will require future studies that correlate tracer uptake with relevant medical and illness history as well as degenerative change evident on traditional imaging.

A Comparison of the Treatment Outcomes With and Without the Use of Intra-articular Corticosteroids for Frozen Shoulder Manipulation

Background Manipulation under anesthesia is known to be an effective treatment method for a frozen shoulder. However, this process is painful and causes difficulty in early physiotherapy. Intra-articular corticosteroids may relieve pain after manipulation. This study compared patients who underwent manipulation under anesthesia with those who only underwent physiotherapy and those who received intra-articular corticosteroid administration and physiotherapy. Methodology A total of 33 patients presenting with frozen shoulders were included in this study. Those who underwent manipulation after anesthesia were determined as group 1 (16 patients) and those who received intra-articular corticosteroids in addition to manipulation under anesthesia were determined as group 2 (17 patients). Pain was evaluated using the Visual Analog Scale (VAS) scores. Functional outcomes were assessed using the University of California-Los Angeles (UCLA) scores and shoulder range of motion (ROM). Results VAS and UCLA scores of both groups were similar at 12 weeks and six months. ROM improved significantly after manipulation in both group 1 and group 2 (p < 0.05). There was no significant difference between the ROM in the two groups after manipulation and physiotherapy. Only the external rotation ROM value was better in group 2 (p = 0.032) Conclusions Physiotherapy after manipulation is a successful treatment method for frozen shoulder patients. It reduces pain in the early period compared to patients who are not administered intra-articular corticosteroids. However, it has no functional superiority.

Atypical progress of frozen shoulder after COVID-19 vaccination: A case report

BACKGROUND

After vaccination was mandated worldwide, various adverse effects associated with the coronavirus disease 2019 (COVID-19) vaccination, including shoulder pain, have been reported. Here, we report a case of new-onset shoulder pain after BNT162b2 (Comirnaty, Pfizer-BioNTech) mRNA vaccination.

CASE SUMMARY

A 50-year-old man visited our rehabilitation center with left shoulder range of motion (ROM) limitation that had persisted for more than 5 mo. The history included no specific noteworthy events, except vaccination. The pain in the patient’s left deltoid muscle appeared 1 day after the second BNT162b2 vaccination and intensified to severe pain. The patient self-administered aspirin, with which the pain subsided immediately, whereas ROM limitation persisted. At the first visit, the patient complained of dull pain and ROM restriction of the left shoulder (flexion 130°, abduction 110°, and external rotation 40°). Among the diagnostic studies conducted for the evaluation of the shoulder, magnetic resonance imaging showed a thickened coracohumeral ligament. Nerve conduction studies and needle electromyography showed no electrodiagnostic abnormalities. The patient received comprehensive rehabilitation for 7 mo and had an overall improvement in pain and ROM of the left shoulder.

CONCLUSION

In this case of severe shoulder pain after COVID-19 vaccination that subsided immediately with aspirin treatment, the exact cause and mechanism of pain are unclear. However, the clinical symptoms and diagnostic workups in our report suggest the possibility that the COVID-19 vaccination triggered an immunochemical response that resulted in shoulder pathology.

Effects of Exercise Intervention (with and without Joint Mobilization) in Patients with Adhesive Capsulitis: A Systematic Review and Meta-Analysis

This review aimed to investigate the effects of exercise and exercise with joint mobilization on shoulder range of motion (ROM) and subjective symptom recovery in patients with adhesive capsulitis (AC). Related Studies published from 2000 to 2021 that were peer-reviewed and for which pre-and post-values could be calculated were extracted from PubMed, CINAHL, SPORTDiscus, and Web of Science. Nine studies met our inclusion criteria. As a result of calculating the standard mean difference (SMD) and 95% confidence intervals (CI), both exercise and exercise with joint mobilization showed a large effect on shoulder ROM and subjective outcomes. The combination showed a more significant effect than exercise alone on shoulder flexion (SMD = -1.59 [-2.34, -0.65]), extension (SMD = -1.47 [-2.05, -0.89]), internal rotation (SMD = -1.77 [-2.17, -1.36], external rotation (SMD = -2.18 [-2.92, -1.44]), and abduction ROM (SMD = -1.99 [CI -3.86, -0.12]). Patients who performed exercise alone showed a higher effect of improvement in subjective function (SMD = 3.15 [2.06, 4.24]) and pain (SMD = 4.13 [1.86, 6.41]). Based on these results, an AC rehabilitation exercise program should be developed by adjusting the amount of exercise and joint mobilization by identifying the patient's needs, subjective symptoms, and ROM.

Living with frozen shoulder. 'Here are the risks. I want the injection'. An interpretative phenomenological analysis

BACKGROUND

Frozen shoulder is a disabling condition characterised by severe pain and loss of shoulder movement and may affect up to 5% of the population. Qualitative research documents debilitating pain and how treatment to reduce pain is a priority for people diagnosed with frozen shoulder. Corticosteroid injections are a principal treatment to reduce the pain of frozen shoulder, however little is known about the patient experience.

OBJECTIVES

This study aims to address this gap in the knowledge by exploring the lived experience of people with frozen shoulder who have undergone an injection and to highlight other novel findings.

DESIGN

This is a qualitative study using interpretative phenomenological analysis. One-to-one, semi-structured interviews were conducted with seven people diagnosed with frozen shoulder who had received a corticosteroid injection as part of their management.

METHODOLOGY

A purposive sample of participants were interviewed via MSTeams™ due to Covid-19 restrictions. Data was collected through semi-structured interviews and analysed in accordance with interpretive phenomenological analysis methods.

RESULTS

Three group experiential themes were identified: the dilemma surrounding injections; the challenges of understanding the causes of frozen shoulder; the impact on self and others.

CONCLUSION

Participants conveyed a strong desire in seeking a corticosteroid injection whilst seemingly dismissing the risks. A novel concept was illuminated as frozen shoulder seemed inextricably linked with the ageing process, which negatively impacted body-image. The impact on others is driven by a sense of the unfamiliar nature of illness and it is incumbent on healthcare professionals to seek opportunities to explore the individual's beliefs.

Positive effects of neuromuscular exercises on pain and active range of motion in idiopathic frozen shoulder: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Frozen shoulder (FS) is characterized by pain and significant loss of active and passive shoulder motion. Strengthening exercises are among the standard exercises used for FS. Neuromuscular exercise (NME) effectively improved pain and the range of motion in shoulder. However, no prior research has looked into the effects of NME compared to strengthening exercises in FS rehabilitation. The aim of the present study was to evaluate the effects of NME compared to strengthening exercises on pain and active range of motion (AROM) in individuals with idiopathic frozen shoulder.

METHODS

Forty individuals with idiopathic frozen shoulder were randomly assigned to either the experimental group (NME with regular physical therapy, n = 20) or the control group (strengthening exercises with regular physical therapy, n = 20). In both groups, the interventions were performed once a day, 5 days a week for 8 weeks. Pain scores on the visual analogue scale (VAS) and AROM of the shoulder were assessed at baseline and after the 8-week treatment. The primary analysis was the group × time interaction.

RESULTS

Two-by-two mixed analysis of variance (ANOVA) revealed a significant group × time interaction for VAS (F = 29.67; p < 0.01); AROM in flexion (F = 12.05; p < 0.01), internal rotation (F = 6.62; p < 0.05) and external rotation (F = 16.93; p < 0.01) in favor of the experimental group. The two-by-two mixed ANOVA revealed a significant main effect of time for VAS (F = 1648.47; p < 0.01); AROM in flexion (F = 591.70; p < 0.01), extension (F = 114.57; p < 0.01), abduction (F = 1602.04; p < 0.01), internal rotation (F = 664.14; p < 0.01) and external rotation (F = 1096.92; p < 0.01). No other significant differences were found.

CONCLUSIONS

NME is superior to strengthening exercises in terms of pain and AROM of shoulder flexion, internal rotation and external rotation in individuals with idiopathic FS. NME could be used to treat individuals with FS.

TRIAL REGISTRATION

Trial registration number: ChiCTR2100054453. Registration date: 17/12/2021.

Comparison of Outcomes of Two Different Corticosteroid Injection Approaches for Primary Frozen Shoulder: A Randomized Controlled Study

OBJECTIVE

Corticosteroid injection is a common treatment for primary frozen shoulder, but controversy remains regarding whether different injection approaches to the glenohumeral joint have similar clinical benefits.

DESIGN

Randomized controlled clinical trial.

PATIENTS

A total of 60 patients with primary frozen shoulder were divided randomly into either anterior or posterior approach groups.

METHODS

Both groups received a 5-mL drug injection, including 1 mL 40 mg/mL triamcinolone acetonide and 4 mL 2% lidocaine. Follow-up time-points were 4, 8 and 12 weeks post-injection. Outcome measures included visual analogue scale score, Constant-Murley score, and passive range of motion of the shoulder joint.

RESULTS

All outcome measures improved over the follow-up period compared with those of previous follow-up time-points within the groups. The primary finding was that the visual analogue scale score in the anterior group was better than that in the posterior group at each follow-up time-point (all p < 0.05). In addition, improvement in function score and external rotation was faster and significant in the anterior group in the early stages (p = 0.02).

CONCLUSION

The anterior approach achieves more satisfactory results in pain control and offers better recovery of functional activity than posterior approach in the early period for primary frozen shoulder.

Risk factors for musculoskeletal disorders among takeaway riders: Up-to-date evidence in Shanghai, China

Background

Musculoskeletal disorders (MSDs) are common occupational diseases. However, the influencing mechanisms were not clear in the new emerging takeaway rider occupation in the catering industry in China.

Methods

A cross-sectional study was conducted using a takeaway rider sample from one of the largest e-platforms, the Mei Tuan Company in Shanghai. The chi-square test was used to compare the sex differences in MSDs according to various factors. Binary logistic regressions were then performed to explore the potential risk factors for the occurrence and severity of MSDs adjusted by age, sex and vehicle type. Crude odds ratios (CORs) and adjusted odds ratios (AORs) and their 95% confidence intervals (CIs) for predictors were reported.

Results

The prevalence of MSDs was found to be 54.9% (n = 361). Shoulders (joint pain: 24.5%, n = 154/629 cases; muscle pain: 29.0%, n = 183/632 cases; muscle numbness: 31.7%, n = 120/379 cases) and neck (joint pain: 17.0%, n = 107/629 cases; muscle pain: 14.1%, n = 89/632 cases; muscle numbness: 15.3%, n = 58/379 cases) were the most affected regions. Irregular meals (often having regular meals: p = 0.03, AOR = 1.89, 95% CI: 1.05-3.39; sometimes: p < 0.01, AOR = 2.54, 95% CI: 1.49-4.34 and seldomly: p < 0.01, AOR = 4.24, 95% CI: 2.28-7.91) were positively associated with the occurrence of MSDs. Work-related factors, including working over 5 years (p = 0.02, AOR = 1.87, 95% CI: 1.10-3.17) and over 51 km of food delivery distance per day (51-75 km: p = 0.02, AOR = 2.13, 95CI%:1.13-4.01; ≥76 km: p < 0.01, AOR = 3.12, 95CI%: 1.44-6.77), were strongly associated with severity.

Conclusion

MSDs were common among takeaway riders. Personal lifestyles (meal irregularity) were found to predict the occurrence, while work-related factors (longer years of employment and prolonged food delivery distance) were positively associated with severity. Public health efforts should be made to prevent MSDs in this population.

Decreased Expression of Leptin among Patients with Shoulder Stiffness

Shoulder stiffness (SS) is a disease that is fibroblastic and inflammatory in nature. Leptin is an adipokine-mediating the fibroblastic and inflammatory processes of various diseases. Our study tried to investigate the role of leptin in SS pathogenesis. Subacromial bursa from stiff and non-stiff shoulders were obtained for reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunoblotting. Subacromial fluid was obtained for enzyme-linked immunosorbent assay. We showed that the expression level of leptin was lower in the subacromial bursae from the stiff shoulders in RT-PCR analysis (p < 0.001) and immunoblotting (p < 0.001). The concentration of leptin was also lower in the subacromial fluid derived from stiff shoulders. The leptin level in the subacromial fluid was positively associated with the constant score, total range of motion, flexion, abduction, and external rotation. The synovial fibroblasts derived from stiff shoulder-retrieved subacromial bursa were treated by 0, 1, and 3 μM leptin. Under RT-qPCR analysis, leptin was shown to dose-dependently decrease the transcription of IL-6, IL-10, and IL-13, but without impact on IL-1β and IL-4 (p < 0.001, p = 0.001, p = 0.001, p = 0.137, and p = 0.883 by ANOVA test, respectively). These results shed light on the role of leptin in orchestrating the disease processes of SS.

Minimally invasive, sustained-release relaxin-2 microparticles reverse arthrofibrosis

Substantial advances in biotherapeutics are distinctly lacking for musculoskeletal diseases. Musculoskeletal diseases are biomechanically complex and localized, highlighting the need for novel therapies capable of addressing these issues. All frontline treatment options for arthrofibrosis, a debilitating musculoskeletal disease, fail to treat the disease etiology-the accumulation of fibrotic tissue within the joint space. For millions of patients each year, the lack of modern and effective treatment options necessitates surgery in an attempt to regain joint range of motion (ROM) and escape prolonged pain. Human relaxin-2 (RLX), an endogenous peptide hormone with antifibrotic and antifibrogenic activity, is a promising biotherapeutic candidate for musculoskeletal fibrosis. However, RLX has previously faltered through multiple clinical programs because of pharmacokinetic barriers. Here, we describe the design and in vitro characterization of a tailored drug delivery system for the sustained release of RLX. Drug-loaded, polymeric microparticles released RLX over a multiweek time frame without altering peptide structure or bioactivity. In vivo, intraarticular administration of microparticles in rats resulted in prolonged, localized concentrations of RLX with reduced systemic drug exposure. Furthermore, a single injection of RLX-loaded microparticles restored joint ROM and architecture in an atraumatic rat model of arthrofibrosis with clinically derived end points. Finally, confirmation of RLX receptor expression, RXFP1, in multiple human tissues relevant to arthrofibrosis suggests the clinical translational potential of RLX when administered in a sustained and targeted manner.

A Review on Current Notion in Frozen Shoulder: A Mystery Shoulder

Frozen shoulder (FS) is a common condition affecting the population between the ages of 30 and 60; the causative agent is idiopathic, sedentary lifestyle, post-traumatic, or secondary to any pathological conditions. The pathology of FS is characterized by cytokine-mediated synovial inflammation with fibroblastic proliferation. The clinical features of FS vary depending on the phase in which the individual is present. The common clinical features are pain, and reduction in the range of motion in the capsular pattern. The available treatment options are medical therapy such as corticosteroid injection, physical therapy, joint mobilization, joint mobilization under anesthesia, and mirror therapy. When all the conservative methods fail then surgical procedures are used which include the surgical release of the restriction formed in the capsule. In conclusion, steroid injection along with physical therapy shows significant improvement in the range of motion and reduction in pain in the shoulder.

The Unhappy Shoulder: A Conceptual Review of the Psychosomatics of Shoulder Pain

INTRODUCTION

Chronic pain is a multifaceted disorder genuinely entangled with psychic and psychosomatic symptoms, which are typically involved in the processes of chronification. The impingement syndrome of the shoulder is no exception to this rule, but several studies have shown respective peculiarities among those with pain and impingement of the shoulder. Notably, chronic pain is a lateralized experience, and, similarly, its psychosomatic correlates may be attached to the hemispheres functionally.

AIM

The present review therefore gives an overview of the respective findings, with regard not only to psychopathology, but also to personality factors and psychologic trauma, since the latter are reportedly associated with chronic pain. Moreover, we acknowledge symmetry as a possible pathogenic factor.

METHODS

This narrative review followed the current standards for conducting narrative studies. Based on prior findings, our research strategy included the relevance of psychotraumatologic and symmetrical aspects, as well as comorbidity. We retrieved the relevant literature reporting on the impact of psychopathology as well as personality features on shoulder pain, as published up to January 2022 from the Medline database (1966-2022). Study selecton: We included numerous studies, and considered the contextual relevance of studies referring to the neuropsychosomatics of chronic pain.

RESULTS

Pain-specific fears, depression, and anxiety are important predictors of shoulder pain, and the latter is generally overrepresented in those with trauma and PTSD. Moreover, associations of shoulder pain with psychological variables are stronger as regards surgical therapies as compared to conservative ones. This may point to a specific and possibly trauma-related vulnerability for perioperative maladaptation. Additionally, functional hemispheric lateralization may explain some of those results given that limb pain is a naturally lateralized experience. Not least, psychosocial risk factors are shared between shoulder pain and its physical comorbidities (e.g., hypertension), and the incapacitated state of the shoulder is a massive threat to the function of the human body as a whole.

CONCLUSIONS

This review suggests the involvement of psychosomatic and psychotraumatologic factors in shoulder impingement-related chronic pain, but the inconclusiveness and heterogeneity of the literature in the field is possibly suggestive of other determinants such as laterality.

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.

si-Tgfbr1-loading liposomes inhibit shoulder capsule fibrosis via mimicking the protective function of exosomes from patients with adhesive capsulitis

BACKGROUND

Adhesive capsulitis is a common shoulder disorder inducing joint capsule fibrosis and pain. When combined with rotator cuff tear (RCT), treatments can be more complex. Currently, targeted therapy is lacking. Since adhesive capsulitis is reported to be related to circulating materials, we analyzed the contents and biology of circulating exosomes from RCT patients with and without adhesive capsulitis, in an attempt to developing a targeting treatment.

METHODS

Samples from a consecutive cohort of patients with RCT for surgery were collected. Circulating exosomal miRNAs sequencing were used to detect differentially expressed miRNAs in patients with and without adhesive capsulitis. For experiments in vitro, Brdu staining, CCK-8 assay, wound healing test, collagen contraction test, real-time quantitative polymerase chain reaction, and western blot were conducted. Histological and immunofluorescent staining, and biomechanical analysis were applied in a mouse model of shoulder stiffness. The characteristics of liposomes loaded with siRNA were measured via dynamic light scattering or electron microscopy.

RESULTS

Circulating exosomal miRNAs sequencing showed that, compared to exosomes from patients without adhesive capsulitis, miR-142 was significantly up-regulated in exosomes from adhesive capsulitis (Exo-S). Both Exo-S and miR-142 could inhibit fibrogenesis, and the anti-fibrotic effect of Exo-S relied on miR-142. The target of miR-142 was proven to be transforming growth factor β receptor 1 (Tgfbr1). Then, liposomes were developed and loaded with si-Tgfbr1. The si-Tgfbr1-loading liposomes exhibited promising therapeutic effect against shoulder stiffness in mouse model with no evidence toxicity.

CONCLUSION

This study showed that, in RCT patients with adhesive capsulitis, circulating exosomes are protective and have anti-fibrotic potential. This effect is related to the contained miR-142, which targets Tgfbr1. By mimicking this biological function, liposomes loaded with si-Tgfbr1 can mitigate shoulder stiffness pre-clinically.

Randomized controlled trial of suprascapular nerve blocks for subacute adhesive capsulitis

BACKGROUND

Shoulder pain and loss of function remain a therapeutic challenge in adhesive capsulitis. Suprascapular nerve blocks, a common treatment in adhesive capsulitis, are considered a safe and effective method for the resolution of pain and restoration of shoulder range of motion (ROM). To our knowledge, no data are available on the use of suprascapular nerve blocks in adhesive capsulitis in the subacute phase.

AIM

The aim of this study was to compare the efficacy of ultrasound-guided suprascapular nerve blocks versus saline injections for treating adhesive capsulitis in the subacute phase.

DESIGN

Randomized double-blinded controlled trial; level of evidence 2.

SETTING

Out-patient consultation of Physical and Rehabilitation Medicine in a general hospital.

POPULATION

Thirty-five patients with subacute adhesive capsulitis.

METHODS

Patients were randomly allocated to receive either 3 successive (1-week interval) ultrasound-guided suprascapular nerve blocks with ropivacaine 5 mL 2 mg/mL (intervention group) or ultrasound-guided injections of 5 mL sterile saline solution (NaCl 0.9%) (control group), at the floor of the suprascapular fossa. Primary outcome was shoulder function assessed by the Constant-Murley Score. Secondary outcomes were shoulder ROM and shoulder pain intensity. Assessments were performed before each injection and 4 weeks after the last injection.

RESULTS

A significant increase of Constant-Murley Score (P<0.001), increase of shoulder ROM (all directions: P<0.011) and decrease of pain (P<0.001), were observed over time in both study groups. However, no significant differences were observed between the intervention and the control group.

CONCLUSIONS

Three successive suprascapular nerve blocks did not provide a better outcome than saline injections on shoulder function, ROM, and pain in subacute adhesive capsulitis. These negative findings warrant some considerations on the natural history of adhesive capsulitis, as well as timing, type, and placebo effects of injections.

CLINICAL REHABILITATION IMPACT

The current place of suprascapular nerve blocks in the treatment strategy of adhesive capsulitis needs to be rediscussed.

Causes of Shoulder Dysfunction in Diabetic Patients: A Review of Literature

Objective: Understanding the underlying mechanisms behind shoulder dysfunctions in patients with diabetes mellitus. Study Design: Systematic qualitative literature review. Participants: Patients with shoulder dysfunctions and diagnosed with impaired glucose tolerance or diabetes mellitus. Intervention: Published scientific literature containing evidence about the mechanisms of shoulder dysfunctions in the diabetic population. Articles were selected based on criteria containing diabetic population, shoulder dysfunction, methodological quality ≥ 6/9 and >20 subjects. Main Outcome measures: range of motion; questionnaires (QoL, UCLA-m, SPADI, DASH); blood glucose, blood HbA1C; calculated capsular stiffness (Kcap); calcification shoulder joint; shoulder dysfunction in patients with glucose metabolism disorders and diabetes mellitus. Results: We found 17 published articles with level 2 and 3 evidence. Multiple factors such as age, duration of diabetes mellitus (DM), glycated hemoglobin (HbA1c), advanced glycation end products (AGE), vascular endothelial growth factor (VEGF), interleukin-1ß (IL-1ß) were shown to be associated with tendon changes and increased capsular stiffness (Kcap) conceivably leading to limited range of motion (ROM) or frozen shoulder. Decreased ROM and frozen shoulder have a significantly higher prevalence in DM than in non-DM. Conclusions: Based on the current literature we confirm a high prevalence of shoulder dysfunctions in patients with diabetes mellitus. The cause of the shoulder complications is unknown, and more research is mandatory to shed more light on the complex interplay between the multifactorial causes of shoulder dysfunction in diabetes mellitus.

Risk Factors for the Onset of Frozen Shoulder in Middle-Aged and Elderly Subjects Within 1 Year of Discharge From a Hospitalization That Involved Intravenous Infusion: A Prospective Cohort Study

AIM

To investigate the incidence of frozen shoulder and risk factors for the onset of frozen shoulder in middle-aged and elderly subjects within 1 year of discharge from a hospitalization that involved intravenous infusion in Zhangjiagang Second People's Hospital.

METHODS

A total of 1,900 subjects who were discharged from a hospitalization that involved intravenous infusion in the hospital between May 2020 and September 2020 met the inclusion criteria for this study: 950 subjects had a mean daily duration of intravenous infusion ≤ 2 h (low exposure) and 950 subjects had a mean daily duration of intravenous infusion ≥3 h (high exposure). Subjects were followed up by telephone at 6 months ± 1 week and 12 months ± 1 week after discharge the incidence of frozen shoulder.

RESULTS

The cumulative incidence rate of frozen shoulder within 1 year of discharge was 5.2%. Multivariate logistic regression analysis revealed the risk of frozen shoulder was higher in subjects with a mean daily duration of intravenous infusion ≥3 h compared to ≤ 2 h (OR = 3.082, 95% CI 1.919-4.949, P < 0.001); subjects hospitalized for 11-30 days had a higher risk of frozen shoulder compared to those hospitalized for 10 days or less (OR = 6.836, 95%CI 4.363-10.709, P < 0.001); subjects who were overweight/ obese (BMI ≥ 25 kg/m²) had a higher risk of frozen shoulder compared to those of normal weight (BMI 18.5-24.9 kg/m²) (OR = 2.166, 95%CI 1.376-3.410, P = 0.001); subjects in the 56-70-year-old age group had a higher risk of developing frozen shoulder compared to those in the 40-55-year-old age group (OR = 1.977, 95%CI 1.154-3.387, P = 0.013); diabetes increased the risk of frozen shoulder (OR = 3.009, 95%CI 1.826-4.959, P < 0.001). The 71-85 years old age group and hypertension were statistically significant in univariate analysis but not in multivariate analysis (P > 0.05).

CONCLUSION

Compared with middle-aged and elderly in the general population, middle-aged and elderly subjects who received intravenous infusion during a hospitalization had a higher cumulative incidence rate of frozen shoulder within 1 year after discharge. Independent risk factors for the onset of frozen shoulder included mean daily duration of intravenous infusion ≥3 h, length of hospital stay 11-30 days, BMI ≥ 25 kg/m², age 56-70 years, and diabetes.