Immunolocalization of cytokines and their receptors in adhesive capsulitis of the shoulder

Adhesive capsulitis of the shoulder: review of pathophysiology and current clinical treatments

Adhesive shoulder capsulitis, or arthrofibrosis, describes a pathological process in which the body forms excessive scar tissue or adhesions across the glenohumeral joint, leading to pain, stiffness and dysfunction. It is a debilitating condition that can occur spontaneously (primary or idiopathic adhesive capsulitis) or following shoulder surgery or trauma (secondary adhesive capsulitis). Here, we review the pathophysiology of adhesive shoulder capsulitis, highlighting its clinical presentation, natural history, risk factors, pathoanatomy and pathogenesis. Both current non-operative and operative treatments for adhesive capsulitis are described, and evidence-based studies are presented in support for or against each corresponding treatment. Finally, the review also provides an update on the gene expression profile of adhesive capsulitis and how this new understanding can help facilitate development of novel pharmacological therapies.

Effectiveness of Biologic Factors in Shoulder Disorders

Background:

Shoulder pathology can cause significant pain, discomfort, and loss of function that all interfere with activities of daily living and may lead to poor quality of life. Primary osteoarthritis and rotator cuff diseases with its sequalae are the main culprits. Management of shoulder disorders using biological factors gained an increasing interest over the last years. This interest reveals the need of effective treatments for shoulder degenerative disorders, and highlights the importance of a comprehensive and detailed understanding of the rapidly increasing knowledge in the field.

Methods:

This study will describe most of the available biology-based strategies that have been recently developed, focusing on their effectiveness in animal and clinical studies.

Results:

Data from in vitro work will also be briefly presented; in order to further elucidate newly acquired knowledge regarding mechanisms of tissue degeneration and repair that would probably drive translational work in the next decade. The role of platelet rich-plasma, growth factors, stem cells and other alternative treatments will be described in an evidence-based approach, in an attempt to provide guidelines for their clinical application. Finally, certain challenges that biologic treatments face today will be described as an initiative for future strategies.

Conclusion:

The application of different growth factors and mesenchymal stem cells appears as promising approaches for enhancing biologic repair. However, data from clinical studies are still limited, and future studies need to improve understanding of the repair process in cellular and molecular level and evaluate the effectiveness of biologic factors in the management of shoulder disorders.

Characteristics of dynamic magnetic resonance imaging of idiopathic severe frozen shoulder

BACKGROUND

The purpose of this study was to evaluate the effectiveness of current techniques for dynamic 3-dimensional magnetic resonance imaging (MRI) in the diagnosis of idiopathic severe frozen shoulder (FS).

MATERIALS AND METHODS

Subjects consisted of 5 healthy volunteers and 16 patients with idiopathic severe FS. We defined severe idiopathic FS as follows: range of motion ≤100° in forward flexion, ≤10° in external rotation, and ≤L5 in internal rotation. All patients suffered from continued global range of motion loss for at least 6 months. We evaluated the diagnostic characteristics of 3-dimensional dynamic MRI in FS patients compared with those in healthy volunteers.

RESULTS

MRI of all FS patients displayed an abnormal intake of blood flow from the acromial arterial network and the branches of circumflex humeral arteries into the axillary pouch and the rotator interval. We named this finding "burning sign." The burning sign was present at all phases of the condition. In the FS group, the patients with enhanced deposition of contrast medium in the axillary pouch in the delayed phase (n = 11) had a statistically significant score for pain during exercise, higher than that of patients with reduced deposition of contrast medium at the same site (n = 5; P = .027).

CONCLUSION

Burning sign is an abnormal finding that appears in dynamic MRI of severe FS. Hence, the burning sign may be associated with pain and inflammation in idiopathic FS.

Correlations of coracohumeral ligament and range of motion restriction in patients with recurrent anterior glenohumeral instability evaluated by magnetic resonance arthrography

BACKGROUND

Evaluation of range of motion (ROM) restriction before treatment of shoulder disorders is important for predicting the final functional outcomes. The purpose of this study was to investigate correlations of thickness of the coracohumeral ligament (CHL) and ROM restriction in patients with recurrent anterior glenohumeral instability.

METHODS

Between January 2005 and March 2015, 181 shoulders (137 male and 44 female patients; mean age, 29.3 years) with recurrent anterior glenohumeral instability treated with an arthroscopic Bankart repair were enrolled in this study. We evaluated preoperative ROM, thickness of the CHL, and obliteration of the subcoracoid fat triangle on magnetic resonance arthrography. ROM measurements, including forward flexion (FF), external rotation with the arm at the side (ER), and hand behind the back (HBB), were made in a standing position.

RESULTS

There were significant negative correlations between FF and age (P < .001) and between HBB and age (P < .001) but not between ER and age (P = .11). The thickness of the CHL significantly increased with age (P < .001). FF, ER, and HBB were significantly restricted in patients with obliteration compared with those without obliteration (P < .001, P = .004, P < .001, respectively).

CONCLUSIONS

Obliteration of the subcoracoid fat triangle and the thickness of the CHL positively correlated with ROM restrictions, and these changes were greater with age in patients with recurrent anterior glenohumeral instability.

Characterization of a frozen shoulder model using immobilization in rats

Background

The objective of this study was to investigate serial changes for histology of joint capsule and range of motion of the glenohumeral joint after immobilization in rats. We hypothesized that a rat shoulder contracture model using immobilization would be capable of producing effects on the glenohumeral joint similar to those seen in patients with frozen shoulder.

Methods

Sixty-four Sprague-Dawley rats were randomly divided into one control group (n = 8) and seven immobilization groups (n = 8 per group) that were immobilized with molding plaster for 3 days, or for 1, 2, 3, 4, 5, or 6 weeks. At each time point, eight rats were euthanized for histologic evaluation of the axillary recess and for measurement of the abduction angle.

Results

Infiltration of inflammatory cells was found in the synovial tissue until 2 weeks after immobilization. However, inflammatory cells were diminished and fibrosis was dominantly observed in the synovium and subsynovial tissue 3 weeks after immobilization. From 1 week after immobilization, the abduction angle of all immobilization groups at each time point was significantly lower than that of the control group.

Conclusions

Our study demonstrated that a rat frozen shoulder model using immobilization generates the pathophysiologic process of inflammation leading to fibrosis on the glenohumeral joint similar to that seen in patients with frozen shoulder. This model was attained within 3 weeks after immobilization. It may serve as a useful tool to investigate pathogenesis at the molecular level and identify potential target genes that are involved in the development of frozen shoulder.

Connective tissue growth factor (CTGF/CCN2) in haemophilic arthropathy and arthrofibrosis: a histological analysis

INTRODUCTION

Joint haemorrhage is the principal clinical manifestation of haemophilia frequently leading to advanced arthropathy and arthrofibrosis, resulting in severe disability. The degree and prevalence of arthrofibrosis in hemophilic arthropathy is more severe than in other forms of arthropathy. Expression of connective tissue growth factor (CTGF) has been linked to many fibrotic diseases, but has not been studied in the context of haemophilic arthropathy.

AIM

We aim to compare synovial tissues histologically from haemophilia and osteoarthritis patients with advanced arthropathy in order to compare expression of proteins that are possibly aetiologic in the development of arthrofibrosis.

METHODS

Human synovial tissues were obtained from 10 haemophilia and 10 osteoarthritis patients undergoing joint surgery and processed for histology and immunohistochemistry.

RESULTS

All samples from haemophilia patients had synovitis with hypertrophy and hyperplasia of synovial villi. Histologically, synovial tissues contained hyperplastic villi with increased cellularity and abundant haemosiderin- and ferritin-pigmented macrophage-like cells (HMCs), with a perivascular localization in the sub-surface layer. CTGF staining was observed in the surface layer and sub-surface layer in all haemophilia patients, exclusively co-localizing with HMCs. Quantification showed that the extent of CTGF-positive areas was correlated with the degree of detection of HMCs. CTGF was not observed in any of the samples from osteoarthritis patients.

CONCLUSION

Using histological analysis, we showed that CTGF expression is elevated in haemophilia patients with arthrofibrosis and absent in patients with osteoarthritis. Additionally, we found that CTGF is always associated with haemosiderin-pigmented macrophage-like cells, which suggests that CTGF is produced by synovial A cells following the uptake of blood breakdown products.

The pathophysiology associated with primary (idiopathic) frozen shoulder: A systematic review

Background

Frozen shoulder is a common yet poorly understood musculoskeletal condition, which for many, is associated with substantial and protracted morbidity. Understanding the pathology associated with this condition may help to improve management. To date this has not been presented in a systematic fashion. As such, the aim of this review was to summarise the pathological changes associated with this primary frozen shoulder.

Methods

Databases: Medline, Embase, CINAHL, AMED, BNI and the Cochrane Library, were searched from inception to 2nd May, 2014. To be included participants must not have undergone any prior intervention. Two reviewers independently conducted the; searches, screening, data extraction and assessment of Risk of Bias using the Cochrane Risk of Bias Assessment Tool for non-Randomised Studies of Interventions (ACROBAT-NRSI). Only English language publications reporting findings in humans were included. The findings were summarised in narrative format.

Results

Thirteen observational studies (involving 417 shoulders) were included in the review. Eight studies reported magnetic resonance imaging or arthrography findings and 5 recorded histological findings. When reported mean ages of the participants ranged from 40.0 to 59.8 years. Duration of symptoms ranged from 0 to 30 months. The majority of studies (n = 7) were assessed to be of moderate risk of bias, two studies at high risk and the remaining four were rated as low risk of bias. Study characteristics were poorly reported and there was widespread variety observed between studies in respect of data collection methods and inclusion criteria employed. Pathological changes in the anterior shoulder joint capsule and related structures were commonly reported. Imaging identified pathological changes occurring in the coracohumeral ligament, axillary fold and rotator interval. Obliteration of the subcoracoid fat triangle also appeared to be pathognomonic. Histological studies were inconclusive but suggested that immune, inflammatory and fibrotic changes where associated with primary frozen shoulder.

Conclusions

This systematic review presents a summary of what is currently known about the tissue pathophysiology of primary frozen shoulder. Further studies that use standardised inclusion and exclusion criteria and investigate changes in naïve tissue at different stages of the condition are required.

The effect of myofibroblasts and corticosteroid injections in adhesive capsulitis

HYPOTHESIS

Adhesive capsulitis is a condition that results in restricted glenohumeral motion. Fibroblasts have been implicated in the disease process; however, their role as a contractile element in the development of fibrosis and capsular contracture is not well understood. We hypothesized (1) that myofibroblast prevalence in capsular biopsy specimens from patients with adhesive capsulitis would be increased compared with controls and (2) that patients treated with an intra-articular injection of corticosteroid would have fewer myofibroblasts.

METHODS

The study prospectively enrolled 20 consecutive patients with adhesive capsulitis scheduled for capsular release and matched controls. Tissue samples were collected from the posterior and anterior capsule for histomorphologic and immunohistologic analyses. Identical sectioning and preparation was performed in 14 additional adhesive capsulitis specimens from patients who had not received corticosteroid injections.

RESULTS

Patients with adhesive capsulitis not treated with preoperative corticosteroid demonstrated more histologic evidence of fibromatosis, synovial hyperplasia, and an increase in positive staining for α-smooth muscle actin than patients who had received intra-articular injections of steroid. No specimens obtained from control patients demonstrated positive staining for α-smooth muscle actin.

DISCUSSION

There was a higher prevalence of myofibroblast staining in patients with adhesive capsulitis, implicating activation of the myofibroblast in the pathophysiology of capsular contracture. Intra-articular steroid injection decreases the presence and amount of fibromatosis, vascular hyperplasia, fibrosis, and the presence of fibroblasts staining for α-smooth muscle actin. This supports the use of steroid injections to alter the disease process by decreasing the pathologic changes found in the capsular tissue.

The roles of Tenascin C and Fibronectin 1 in adhesive capsulitis: a pilot gene expression study

OBJECTIVES

We evaluated mRNA expression levels of genes that encode TGF-β1; the TGF-β1 receptor; the collagen-modifying enzymes LOX, PLOD1, and PLOD2; and the extracellular matrix proteins COMP, FN1, TNC and TNXB in synovial/capsule specimens from patients with idiopathic adhesive capsulitis. Possible associations between the measured mRNA levels and clinical parameters were also investigated.

METHODS

We obtained glenohumeral joint synovium/capsule specimens from 9 patients with idiopathic adhesive capsulitis who had not shown improvement in symptoms after 5 months of physiotherapy. Adhesive capsulitis was confirmed in all patients by magnetic resonance imaging. We also obtained specimens from 8 control patients who had underwent surgery for acute acromioclavicular joint dislocation and who had radiological indication of glenohumeral capsule alteration based on arthroscopic evaluation. mRNA expression in the synovium/capsule specimens was analyzed by quantitative reverse transcription PCR. The B2M and HPRT1 genes were used as references to normalize target gene expression in the shoulder tissue samples.

RESULTS

The synovium/capsule samples from the patients with adhesive capsulitis had significantly higher TNC and FN1 expression than those from the controls. Additionally, symptom duration directly correlated with expression of TGFβ1 receptor I.

CONCLUSION

Elevated levels of TNC and FN1 expression may be a marker of capsule injury. Upregulation of TGFβ1 receptor I seems to be dependent on symptom duration; therefore, TGFβ signaling may be involved in adhesive capsulitis. As such, TNC, FN1 and TGFβ1 receptor I may also play roles in adhesive capsulitis by contributing to capsule inflammation and fibrosis.

Advanced glycation end products in idiopathic frozen shoulders

BACKGROUND

The pathophysiologic mechanisms behind proliferation of fibroblasts and deposition of dense collagen matrix in idiopathic frozen shoulder remain unclear. Accumulation of advanced glycation end products (AGEs) with cross-linking and stabilization of collagen has been hypothesized to contribute to this pathophysiologic process. This study investigated whether the immunoreactivity of AGEs is higher in patients with idiopathic frozen shoulder than in the control groups.

METHODS

Shoulder capsule samples were collected from 8 patients with idiopathic frozen shoulder, 6 with unstable shoulders (control 1), and 8 with rotator cuff tears (control 2). The samples were hematoxylin and eosin stained and analyzed by immunohistochemistry using antibodies against AGEs. Immunoreactivities were rated in a blinded fashion from none (0) to strong (3). Immunohistochemical distribution within the capsule was noted.

RESULTS

Frozen shoulder patients had greater frequency and severity of self-reported pain (P = .02) than rotator cuff tear patients and more restricted range of motion in all planes (P < .05) than patients of the instability and rotator cuff tear groups. Hematoxylin and eosin-stained capsular tissue from frozen shoulder showed fibroblastic proliferation, increased numbers of adipocytes, and increased subsynovial vascularity. Immunoreactivity of AGEs was stronger in frozen shoulder capsules (2.8) than in instability (0.3; P = .0001) and rotator cuff tear (1.1; P = .016) capsules.

CONCLUSION

This study highlights a potential role for AGEs in the pathogenesis of frozen shoulder. The overexpression of AGEs may explain the fibroblastic proliferation and deposition of collagen matrix in idiopathic frozen shoulder.

LEVEL OF EVIDENCE

Basic Science Study; Histology.

Expression analysis of genes involved in collagen cross-linking and its regulation in traumatic anterior shoulder instability

The molecular alterations involved in the capsule deformation presented in shoulder instability patients are poorly understood. Increased TGFβ1 acts as a signal for production of matrix macromolecules by fibrogenic cells at joint injury sites. TGFβ1, through its receptor TGFβR1, regulates genes involved in collagen cross-linking, such as LOX, PLOD1, and PLOD2. We evaluated TGFβ1, TGFβR1, LOX, PLOD1, and PLOD2 gene expression in the antero-inferior (macroscopically injured region), antero-superior and posterior regions of the glenohumeral capsule of 29 shoulder instability patients and eight controls. We observed that PLOD2 expression was increased in the anterior-inferior capsule region of the patients compared to controls. LOX expression tended to be increased in the posterior portion of patients. Patients with recurrent shoulder dislocation presented upregulation of TGFβR1 in the antero-inferior capsule portion and of PLOD2 in the posterior region. Conversely, LOX was increased in the posterior portion of the capsule of patients with a single shoulder dislocation episode. In the antero-inferior, LOX expression was inversely correlated and TGFβR1 was directly correlated with the duration of symptoms. In the posterior region, PLOD2, TGFβ1, and TGFβR1 were directly correlated with the duration of symptoms. In conclusion, PLOD2 expression was increased in the macroscopically injured region of the capsule of patients. Upregulation of TGFβ1, TGFβR1, and PLOD2 seems to be related with the maintenance of disease symptoms, especially in the posterior region. LOX upregulation seems to occur only in the initial phase of the affection. Therefore, TGFβ1, TGFβR1, LOX, and PLOD2 may play a role in shoulder instability.

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.

Adhesive capsulitis of the shoulder and diabetes: a meta-analysis of prevalence

BACKGROUND

adhesive capsulitis (AC) results in progressive painful restriction in range of movement and can reduce function and quality of life. Whilst it has been associated with diabetes mellitus (DM), there is considerable variation in the reported prevalence of AC in the diabetic population. The aim of this study is to determine through meta-analysis the prevalence of AC in DM and examine whether it is influenced by type of DM or insulin therapy. We also aim to further establish the prevalence of DM in patients presenting with AC.

METHODS

we conducted a literature search for terms regarding AC and DM on Embase and Pubmed NCBI.

RESULTS

of 5411 articles identified, 18 were selected. Meta-analysis showed that patients with DM were 5 (95% CI 3.2-7.7) times more likely than controls to have AC. The overall prevalence of AC in DM was estimated at 13.4% (95% CI 10.2-17.2%). Comparison of prevalence in patients on insulin vs other treatments showed no significant difference between the two. Meta-analysis estimated the prevalence of DM in AC at 30% (95% CI 24-37%).

CONCLUSION

to our knowledge this is the first meta-analysis to estimate the overall prevalence of diabetes in a population with AC. A high prevalence of AC exists in DM and equally a high prevalence of DM is present in AC. Screening for DM should be considered in patients presenting with AC.

Magnetic resonance imaging and short-term clinical results of severe frozen shoulder treated with manipulation under ultrasound-guided cervical nerve root block

BACKGROUND

We evaluated the magnetic resonance (MR) imaging findings and short-term clinical outcomes of severe idiopathic frozen shoulder treated with manipulation under ultrasound-guided cervical nerve root block (MUC).

METHODS

The subjects were 30 patients (average age, 55.2 years; 12 men, 18 women) with severe frozen shoulder. Severe idiopathic frozen shoulder was defined as follows: a range of motion (ROM) of ≤ 100° in forward flexion, ≤ 10° in external rotation, and at or below the fifth lumbar vertebral level in internal rotation. Before the manipulation, all patients had continued global ROM loss for at least 6 months. Before and after manipulation, they underwent MR imaging. MR images and clinical results were evaluated 1 month after the procedure.

RESULTS

In terms of the capsule tear pattern, MR imaging showed 14 midsubstance tears and 15 humeral avulsions of glenohumeral ligament-like lesions. An anterior labrum tear occurred in 4 shoulders, whereas 15 shoulders showed a bone bruise in the posterosuperior and anteromedial portions of the humeral head despite no humeral shaft fracture. There were significant improvements in the ROM, Constant-Murley score, American Shoulder and Elbow Surgeons score, and Numeric Rating Scale score from before treatment to 1 month after the procedure.

CONCLUSION

MR imaging of patients with severe frozen shoulder after MUC showed 29 capsule tears, 4 labrum tears, and 15 bone bruises of the humeral head. Approximately 50% of patients are likely to experience bone bruising after MUC. Long-term follow-up of these patients should be performed carefully.

In vivo kinetic evaluation of an adhesive capsulitis model in rats

BACKGROUND AND HYPOTHESIS

We hypothesized that extra-articular, internal fixation of the shoulder in rats would result in a subsequent decrease in rotational range of motion (ROM) and an increase in joint stiffness. We further hypothesized that residual kinematic changes would still be present at 8 weeks after immobilization. Extra-articular, internal fixation of the shoulder has been used to induce adhesive capsulitis in rats; however, the effects on in vivo kinematics have not been assessed.

METHODS

Baseline measurements of rotational torque and ROM were acquired (n = 10 rats), and the left forelimb of each animal was immobilized with sutures passed between the scapula and the humeral shaft. After 8 weeks, the sutures were removed, and changes in kinematics and kinetics were longitudinally quantified in the follow-up period. Changes in stiffness, defined as the area under the angle-torque curve, were also quantified.

RESULTS

Immediately after suture removal, there was a 63% decrease in total ROM compared with baseline (51° ± 10° vs. 136° ± 0°; P < .001). Similarly, total torque was found to increase 13.4 N.mm compared with baseline (22.6 ± 5.9 N.mm vs. 9.2 ± 2.6 N.mm; P = .002). Residual total ROM restrictions and an increased torque in internal rotation were still evident at 8 weeks of follow-up (113° ± 8° vs. 137° ± 0°, P < .001 and 3.5 ± 0.4 N.mm vs. 2.7 ± 0.7 N.mm, P = .036). Stiffness also increased after suture removal and at 8 weeks of follow-up compared with baseline.

CONCLUSION

This animal model of adhesive capsulitis rendered lasting effects on in vivo kinematics of the shoulder.

Evaluation of the Effusion within Biceps Long Head Tendon Sheath Using Ultrasonography

BACKGROUND

Many shoulder diseases are related to glenohumeral joint synovitis and effusion. The purpose of the present study is to detect effusion within the biceps long head tendon sheath as the sign of glenohumeral joint synovitis using ultrasonography, and to evaluate the clinical meaning of effusion within the biceps long head tendon sheath.

METHODS

A consecutive series of 569 patients who underwent ultrasonography for shoulder pain were reviewed retrospectively and ultimately, 303 patients were included. The authors evaluated the incidence and amount of the effusion within the biceps long head tendon sheath on the ultrasonographic short axis view. Furthermore, the authors evaluated the correlation between the amount of effusion within the biceps long head tendon sheath and the range of motion and the functional score.

RESULTS

The effusion within the biceps long head tendon sheath was detected in 58.42% of the patients studied: 69.23% in adhesive capsulitis, 56.69% in rotator cuff tear, 41.03% in calcific tendinitis, and 33.33% in biceps tendinitis. The average amount of the effusion within the biceps long head tendon sheath was 1.7 ± 1.6 mm, and it was measured to be the largest in adhesive capsulitis. The amount of effusion within biceps long head tendon sheath showed a moderate to high degree of correlation with the range of motion, and a low degree of correlation with the functional score and visual analogue scale for pain in each type of shoulder disease.

CONCLUSIONS

The effusion within the biceps long head tendon sheath is closely related to the range of motion and clinical scores in patients with painful shoulders. Ultrasonographic detection of the effusion within the biceps long head tendon sheath might be a simple and easy method to evaluate shoulder function.

Up-regulation of acid-sensing ion channels in the capsule of the joint in frozen shoulder

The purpose of this study was to evaluate the expression of acid-sensing ion channels (ASICs) in the capsule and synovial fluid of patients with frozen shoulder. Capsular tissue and synovial fluid were obtained from 18 patients with idiopathic frozen shoulder (FS group) and 18 patients with instability of the shoulder (control group). The expressions of ASIC1, ASIC2, and ASIC3 in the capsule were determined using the reverse transcriptase-polymerase chain reaction, immunoblot analysis, and immunohistochemistry (IHC). The concentrations in synovial fluid were evaluated using an enzyme-linked immunosorbent assay.

The mRNA expression of ASIC1, ASIC2 and ASIC3 in the capsule were significantly increased in the FS group compared with the control group. The protein levels of these three ASICs were also increased. The increased expressions were confirmed by IHC. Of the ASICs, ASIC3 showed the greatest increase in both mRNA and levels of expression compared with the control group. The levels of ASIC1 and ASIC3 in synovial fluid were significantly increased in the FS group.

This study suggests that ASICs may play a role as mediators of inflammatory pain and be involved in the pathogenesis of frozen shoulder.

Cite this article: Bone Joint J 2015;97-B:824–9.

Arthroscopic capsular release and manipulation under anaesthesia for frozen shoulders: A hot topic

A frozen shoulder is a common cause of shoulder pain and stiffness. The etiology and pathology of frozen shoulders is not fully understood yet. Frozen shoulder is characterized by a decrease in intra-articular volume and capsular compliance. This can lead to significant limitations in daily life. The majority of the patients can be treated conservatively, with functional recovery to be expected in two to three years. However, if conservative treatment fails, manipulation under anaesthesia and arthroscopic capsular release can both be considered as appropriate treatments. Manipulation is a traditionally well-established technique but in recent years it seems that arthroscopic capsular release has gained popularity. Manipulation is a relative time efficient and technically low-demanding procedure in which the glenohumeral joint is forced into different directions under general anaesthesia to release the capsular contracture, thereby increasing the range of motion of the joint. In arthroscopic capsular release the glenohumeral capsule can be released in a more controlled manner under direct vision. There are no prospective comparative trials available to display superiority of one procedure over the other. In addition, the optimal timing of both these interventions still has to be determined. An overview of the literature concerning this topic and a description of both procedures with its own advantages and disadvantages is provided.

Effectiveness of hyaluronic acid administration in treating adhesive capsulitis of the shoulder: a systematic review of randomized controlled trials

Introduction. Adhesive capsulitis (AC) of the shoulder presents with an insidious onset of pain and progressive limitation of shoulder movement. Objectives. To investigate whether intra-articular hyaluronic acid (HA) administration alone is superior to conventional therapies and whether the addition of intra-articular HA administration to conventional therapies improves clinical outcomes in patients with AC. Methods. The PubMed, EMBASE, CINAHL, and Cochrane Library electronic databases were searched without language restrictions in July 2014 with a priori defined inclusion and exclusion criteria. Results. Four randomized controlled trials (273 participants, 278 shoulders) were included in this review. Two trials compared intra-articular HA administration with conventional therapies and 2 trials evaluated intra-articular HA administration as an addition to conventional therapies. Pain and shoulder function/disability outcomes in the HA injection group were not superior to those achieved in the conventional therapy groups. No significant differences in pain or shoulder function/disability outcomes were noted between the groups with and without adjunctive HA administration. Conclusions. Intra-articular HA administration alone is not superior to conventional AC treatments, and the addition of intra-articular HA administration to conventional therapies does not provide significant added benefits. HA administration in AC patients who are receiving conventional therapies should be evaluated to avoid unnecessary medical expenditure.

Joint haemorrhage partly accelerated immobilization-induced synovial adhesions and capsular shortening in rats

PURPOSE

To elucidate the effects of intra-articular haemorrhage on the joint capsule of immobilized knees in rats.

METHODS

The unilateral knee joints were immobilized using a plastic plate and screws. Sham operated rats had only screws inserted. A single injection of fresh autologous blood was given postoperatively into the knee joints of the immobilized blood injection (Im-B) and the Sham blood injection (Sm-B) groups. Normal saline was administered for the immobilized-saline injection (Im-S) group. Sagittal sections were prepared from the medial midcondylar region of the knee and assessed with histological, histomorphometric, and immunohistochemical methods. The range of motion (ROM) was measured, and the mechanical property of the capsule was assessed by scanning acoustic microscope.

RESULTS

Absorption of the injected blood was delayed and made severe adhesions in the Im-B group. The length of the synovial membrane in the Im-B group was significantly shorter than that of the other groups. The ROM was significantly restricted in the Im-B group compared with the other groups. The elasticity of the posterior capsule in the Im-B group was significantly lower than that in the Sm-B group. Iron deposition was observed in the Im-B and Sm-B groups. Strong immunoreactivities of CD68, TGF-β1, and α-SMA were observed in the adhesion area of the Im-B group. Joint immobilization with blood injection caused severe capsular adhesion and limited range of motion. Immunostaining related to fibrosis increased with joint haemorrhage.

CONCLUSION

Intra-articular haemorrhage with joint immobilization might be an accelerated risk factor for joint contracture. It is likely that leaving a haematoma inside an immobilized joint should be avoided.

MR imaging of extrasynovial inflammation and impingement about the knee

The knee has unique anatomy regarding the relationship between the synovial and capsular layers, with interposed fat pads at certain locations. The extrasynovial impingement and inflammation syndromes about the knee are underdiagnosed and should be included in the differential diagnosis of anterior knee pain. MR imaging is the best imaging modality for evaluation of the anatomy and disorders of these extrasynovial compartments.

Effect of isolated hyperglycemia on native mechanical and biologic shoulder joint properties in a rat model

Recently, diabetes has been linked to rotator cuff disease and adhesive capsulitis, conditions with increased stiffness and inflammation. Unfortunately, limited research exists examining how hyperglycemia affects the native shoulder (tendon and capsule) properties. Therefore, the objectives of this study were to compare shoulder joint mechanics, tendon properties (mechanics and immunohistochemistry), and capsule of healthy control and hyperglycemic rats 8 weeks following induction of hyperglycemia with a submaximal dose of streptozotocin (STZ). Eighteen rats were injected with STZ to induce hyperglycemia or citrate buffer (control) and underwent normal cage activity for 8 weeks. Passive joint mechanics demonstrated significantly less external rotation in the hyperglycemic group compared to controls, with no other group differences. Tendon mechanical properties (stiffness and modulus) were not significantly different between groups at both the insertion site and mid-substance. Immunohistochemistry staining of the tendon and capsule demonstrated significantly increased interleukin 1-beta (IL1-β) and advanced glycated end-products (AGE) staining localized to the insertion and mid-substance of the tendon but not the capsule. In addition, tumor necrosis factor alpha (TNF-α) staining was significantly increased in the superior capsule but not the supraspinatus tendon. This study demonstrates that isolated hypergylcemia does not diminish shoulder mechanical properties but does induce a chronic inflammatory response.

Inhibition of fibrous adhesion formation in the temporomandibular joint of tenascin-C knockout mice

Tenascin-C (TNC) is a large hexameric extracellular matrix glycoprotein that is expressed in developing organs and tumors. It has been reported that TNC is expressed in inflamed synovial membranes and deformed discs of temporomandibular joint (TMJ) disorder. However, the role of TNC in TMJ is not fully known. In this study, the role of TNC in fibrous adhesion formation of TMJ was examined using TNC knockout (TNCKO) mice. Hypermobility was produced by excessive mouth opening method on the TMJ of both wild-type (WT) and TNCKO mice. TMJ wound healing was compared histologically, and the expression of TNC, fibronectin (FN) and α-smooth muscle actin (α-SMA) in the wounded TMJ was examined by immunohistochemical and immunoblot analyses. Based on histologic analysis, fibrous adhesions were observed in the TMJ of both TNCKO and wild-type (WT) mice after excessive mouth opening. However, fibrous adhesion formation in TNCKO mice occurred later than in WT mice. TNC was expressed in the wounded TMJ disc and mandibular fossa. Although FN and α-SMA expression in the TMJ of TNCKO and WT mice was up-regulated after excessive mouth opening, FN and α-SMA protein levels were higher in WT mice at the same time points. In the wounded TMJ, TNC appears to enhance the expression of FN and α-SMA, and a lack of TNC may reduce fibrous adhesion formation in the TMJ. TNC plays an important role in TMJ wound healing, especially for wounds generated by mechanical stress.

Measurement of Capsular Thickness in Magnetic Resonance Arthrography in Idiopathic Adhesive Capsulitis of Hip

Purpose

The clinical suspicion of idiopathic adhesive capsulitis of the hip (IACH) involves restricted range of motion and normal hip radiographs. The purpose of this study was to delineate the characteristic findings observed on magnetic resonance arthrography (MRA) by identifying the anatomical structures involved and their significance on clinical presentation of restricted range of motion.

Materials and Methods

We retrospectively evaluated MRA's of 46 hips (44 patients) who suffered hip pain from September 2006 to August 2012 in our hospital. Of those, 10 cases (8 patients) with clinical suspicion of IACH were compared to 20 normal hip cases (control group). To identify anatomical evidence of adhesive capsulitis in the MRA's of the IACH group, capsular thickness was measured superiorly, inferiorly, anteriorly and posteriorly, and compared to that of the randomly selected control group.

Results

Comparison of the MRA findings of the control group to that of the IACH group showed that there was a statistically significant increase in the mean thickness of the joint capsule superiorly and posteriorly (P<0.01), while comparison of examination findings revealed a statistically significant decrease in the mean range of motion (flexion 122.5°±5.5°/abduction 28.0°±2.8°/adduction 26.5°±2.4°/external rotation 30.5°±3.8°/internal rotation 25.5°±2.4°) in the IACH group.

Conclusion

A change in the capsular thickness on MRA is a common finding in IACH patients with the increase more evident in the posterior and superior capsules than the anterior and inferior capsules.

Melatonin Plays a Role as a Mediator of Nocturnal Pain in Patients with Shoulder Disorders

BACKGROUND

Nocturnal pain is commonly observed in patients with shoulder disorders such as a rotator cuff tear or frozen shoulder. This study was conducted to explore the possibility that melatonin plays a role as a mediator of nocturnal pain in patients with a rotator cuff tear or frozen shoulder.

METHODS

Subacromial bursa and joint capsule samples were collected from sixty-three patients: twenty-one patients with a rotator cuff tear, twenty-two with frozen shoulder, and twenty with shoulder instability (control group). The expression of melatonin receptor 1A (MTNR1A) and 1B (MTNR1B) and of acid-sensing ion channel 3 (ASIC3) in the subacromial bursa and the joint capsule were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. The protein level of ASIC3 was measured by immunoblot analysis. To determine the effect of melatonin as a pain mediator, an in vitro study with use of primary cultured fibroblast-like synoviocytes was performed by semiquantitative RT-PCR analysis, immunoblot analysis, and enzyme-linked immunosorbent assay (ELISA).

RESULTS

MTNR1A, MTNR1B, and ASIC3 expression was significantly increased in both the rotator cuff tear and frozen shoulder groups compared with the control group of patients with shoulder instability. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) significantly stimulated the expression of MTNR1A and MTNR1B in primary cultured fibroblast-like synoviocytes treated with proinflammatory cytokines. Melatonin treatment at a physiological concentration (10 nM) induced ASIC3 expression and IL-6 production. Treatment with luzindole, a melatonin-receptor antagonist, reversed melatonin-stimulated ASIC3 expression and IL-6 production.

CONCLUSIONS

Our study suggests that melatonin may play a role as a mediator of nocturnal pain with a rotator cuff tear or frozen shoulder, and this effect may be mediated via melatonin receptors.

CLINICAL RELEVANCE

Melatonin may be a therapeutic target of chronotherapy.

The association of metabolic syndrome markers with adhesive capsulitis

BACKGROUND

Research has associated adhesive capsulitis with diabetes mellitus but suggests that glucose-mediated injury may begin before diabetes is diagnosed. The period preceding diabetes is often marked by metabolic syndrome.

METHODS

We investigated the relationship between metabolic syndrome components (insulin resistance, hypertension, dyslipidemia, and obesity) and the development of adhesive capsulitis using a case-control study. We retrospectively reviewed 150 consecutive adhesive capsulitis patient charts to determine the prevalence of obesity and of medications used for treating metabolic syndrome elements and compared these with previously reported nationwide values.

RESULTS

The prevalence of anti-hyperglycemia medications in the adhesive capsulitis cohort was 18.4% (95% confidence interval [CI], 12.9%-25.7%), twice the national rate of diagnosed diabetes of 7.6% (95% CI, 6.7%-8.5%). In the 20- to 39-year-old group, the prevalence of anti-hyperglycemic medications, 26.3% (95% CI, 11.8%-48.8%), was over 10 times the nationwide rate. The overall prevalence of hypertensive medication use in the adhesive capsulitis group, 33.1% (95% CI, 25.9%-41.2%), was notably higher than the nationwide rate, 21.6% (95% CI, 19.8%-23.4%). In the 40- to 64-year-old group, the prevalence of hypertensive medication use, 36.8% (95% CI, 28.6%-46.0%), was notably higher than the nationwide rate of 24.5% (95% CI, 22.2%-27.0%). The prevalence of anti-lipid medications and obesity was similar between the groups.

CONCLUSIONS

The relationship between adhesive capsulitis and metabolic syndrome remains unclear. Our results confirm previous work associating hyperglycemia with adhesive capsulitis. We have also shown a possible association of hypertension, part of metabolic syndrome and a proinflammatory condition, with adhesive capsulitis, which has not been previously described.

Clinical outcomes do not support arthroscopic posterior capsular release in addition to anterior release for shoulder stiffness: a randomized controlled study

BACKGROUND

Arthroscopic capsular release is an effective treatment for shoulder stiffness, yet its extent is controversial.

PURPOSE

To compare the clinical outcomes of arthroscopic capsular release in patients with and without posterior extended capsular release for shoulder stiffness.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Between January 2008 and March 2011, 75 patients who underwent arthroscopic capsular release for shoulder stiffness were enrolled and randomized into 2 groups. In group I (n = 37), capsular release was performed, including release of the rotator interval and anterior and inferior capsule. In group II (n = 38), capsular release was extended to the posterior capsule. The American Shoulder and Elbow Surgeons score, Simple Shoulder Test, visual analog scale for pain, and range of motion (ROM) were used for the evaluation before surgery and at 3, 6, and 12 months after surgery and at the last follow-up.

RESULTS

Preoperative demographic data of age, sex, symptom duration, and clinical outcomes showed no significant differences (P > .05). The average follow-up was 18.4 months. Both groups showed significantly increased ROM at the last follow-up compared with preoperative ROM (P < .05). At the last follow-up, no statistical differences were found (P > .05) between groups I and II in American Shoulder and Elbow Surgeons score (91.3 vs. 79.5), Simple Shoulder Test (83.3 vs. 83.3), and visual analog scale (1.5 vs. 2.2). There were also no statistical differences between the 2 groups at the last follow-up (P > .05) in ROM: forward flexion, 145.2° vs. 143.3°; external rotation with 90° of abduction, 88.1° vs. 86.2°; external rotation at side, 88.9° vs. 82.9°; and internal rotation, 9.1° vs. 8.3°.

CONCLUSION

Posterior extended capsular release might not be necessary in arthroscopic surgery for shoulder stiffness.

Effect of capsular release in the treatment of shoulder stiffness concomitant with rotator cuff repair: diabetes as a predisposing factor associated with treatment outcome

BACKGROUND

In spite of the high prevalence of shoulder stiffness during rotator cuff repair, optimal management remains unclear.

PURPOSE

To identify the effect of capsular release during rotator cuff repair on the outcomes of patients with both shoulder stiffness and a rotator cuff tear, based on subgroup analyses.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Forty-nine consecutive patients (mean age, 61.5 ± 8.3 years) were enrolled who underwent arthroscopic repair of a small- to large-sized full-thickness rotator cuff tear and manipulation for concomitant shoulder stiffness (passive forward flexion ≤120°, external rotation at the side ≤45°). The first 21 consecutive patients underwent manipulation alone to treat stiffness; the second 28 consecutive patients underwent capsular release with manipulation. Among the 49 patients, 25 showed severe stiffness (forward flexion ≤100°, external rotation at the side ≤30°; 11 in the first series and 14 in the second series), and 15 had diabetes mellitus (30.6%; 6 in the first series and 9 in the second series). Shoulder range of motion was measured 6 weeks, 3 months, 6 months, and 1 year postoperatively and at final follow-up visit. Simultaneously, functional outcome was evaluated by visual analog scale for pain, American Shoulder and Elbow Surgeons score, Constant score, and muscle strength ratio (involved/uninvolved), and cuff integrity was assessed ultrasonographically at least 1 year postoperatively.

RESULTS

All range of motion measurements, functional scores, and muscle strength ratios significantly improved postoperatively regardless of the treatment method of stiffness. No outcome measure differed significantly between patients who did and did not undergo capsular release, regardless of the severity of stiffness, except for a temporary improvement in external rotation at side 3 months postoperatively in favor of those who underwent capsular release in cases with severe stiffness. Among patients with diabetes mellitus however, those who underwent capsular release showed greater improvement in forward flexion after 3 months and 1 year and in external rotation at the side for all time points (all P < .05), except for 6 weeks postoperatively; these patients also had a significantly higher final American Shoulder and Elbow Surgeons score (P = .03). Of 21 patients who underwent manipulation alone and of 28 who underwent capsular release and manipulation, 2 and 1 developed retears, respectively.

CONCLUSION

Both manipulation and capsular release with manipulation significantly improved range of motion and produced satisfactory functional outcomes. The outcomes did not differ between treatment methods for stiffness regardless of the severity of stiffness. In patients with diabetes mellitus however, capsular release at the time of rotator cuff repair seems to be beneficial, especially for external rotation and final postoperative function.

Hyperthyroidism is a risk factor for developing adhesive capsulitis of the shoulder: a nationwide longitudinal population-based study

The purpose of this study was to investigate the prevalence and risk of adhesive capsulitis among hyperthyroidism patients. The data were obtained from the Longitudinal Health Insurance Database 2005 (LHID 2005) in Taiwan, using 1 million participants and a prospective population-based 7-year cohort study of survival analysis. The ambulatory-care claim records of patients diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes relating to hyperthyroidism between January 1, 2004 and December 31, 2007, were obtained. The prevalence and the adjusted hazard ratio (HR) of adhesive capsulitis among hyperthyroid patients and the control group were estimated. Of 4472 hyperthyroid patients, 162 (671/100 000 person-years) experienced adhesive capsulitis during the 24 122 person-year follow-up period. The crude HR of stroke was 1.26 (95% confidence interval [CI], 1.06 to 1.49), which was larger than that of the control group. The adjusted HR of developing adhesive capsulitis was 1.22 (95% CI, 1.03 to 1.45) for hyperthyroid patients during the 7-year follow-up period, which achieved statistical significance. The results of our large-scale longitudinal population-based study indicated that hyperthyroidism is an independent risk factor of developing adhesive capsulitis.

The Mature Athlete's Shoulder

CONTEXT

The mature athlete's shoulder remains a challenging clinical condition to manage. A normal natural history of the shoulder includes stiffness, rotator cuff tears, and osteoarthritis, all of which can become increasingly more symptomatic as an athlete ages.

EVIDENCE ACQUISITION

PubMed (1978-2013).

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 3-4.

RESULTS

Rotator cuff pathology increases with age and activity level. Partial tears rarely heal, and debridement of significant partial tears results in poorer outcomes than those of repair. Repair of partial-thickness tears can be accomplished with completion and subsequent repair or in situ repair. The most successful result for treatment of osteoarthritis in the shoulder remains total shoulder arthroplasty, with more than 80% survival at 20 years and high rates of return to sport. Caution should be taken in patients younger than 60 years, as they show much worse results with this treatment. Adhesive capsulitis of the shoulder can be successfully treated with nonoperative management in 90% of cases.

CONCLUSION

Mature athletes tend to have rotator cuff pathology, osteoarthritis, and stiffness, which may limit their participation in athletic events. Age is a significant consideration, even within the "mature athlete" population, as patients younger than 50 years should be approached differently than those older than 65 years with regard to treatment regimens and postoperative restriction.

Transforming growth factor-β (TGF-β) expression is increased in the subsynovial connective tissues of patients with idiopathic carpal tunnel syndrome

Non-inflammatory fibrosis of the subsynovial connective tissue (SSCT) is a hallmark of carpal tunnel syndrome (CTS). The etiology of this finding and its relationship to the development of CTS remain poorly understood. Recent studies have found that transforming growth factor-β (TGF-β) plays a central role in fibrosis. The purpose of this study was to investigate the expression of TGF-β and connective tissue growth factor (CTGF), a downstream mediator of TGF-β, in the pathogenesis of CTS. We compared SSCT specimens from 26 idiopathic CTS patients with specimens from 10 human cadaver controls with no previous diagnosis of CTS. Immunohistochemistry was performed to determine levels TGF-β1, CTGF, collagen 1(Col1) and collagen 3 (Col3) expression. TGF-β1 (p < 0.01), CTGF (p < 0.01), and Col3 (p < 0.01) were increased in SSCT of CTS patients compared with control tissue. In addition, a strong positive correlation was found between TGF-β1 and CTGF, (R(2) = 0.80, p < 0.01) and a moderate positive correlation between Col3 and TGF-β1 (R(2) = 0.49, p < 0.01). These finding suggest that there is an increased expression of TGF-β and CTGF, a TGF-β regulated protein, and that this TGF-β activation may be responsible for SSCT fibrosis in CTS patients.

Primary frozen shoulder: brief review of pathology and imaging abnormalities

BACKGROUND

Primary frozen shoulder (FS) is a painful contracture of the glenohumeral joint that arises spontaneously without an obvious preceding event. Investigation of the intra-articular and periarticular pathology would contribute to the treatment of primary FS.

REVIEW OF LITERATURE

Many studies indicate that the main pathology is an inflammatory contracture of the shoulder joint capsule. This is associated with an increased amount of collagen, fibrotic growth factors such as transforming growth factor-beta, and inflammatory cytokines such as tumor necrosis factor-alpha and interleukins. Immune system cells such as B-lymphocytes, T-lymphocytes and macrophages are also noted. Active fibroblastic proliferation similar to that of Dupuytren's contracture is documented. Presence of inflammation in the FS synovium is supported by the synovial enhancement with dynamic magnetic resonance study in the clinical setting.

CONCLUSION

Primary FS shows fibrosis of the joint capsule, associated with preceding synovitis. The initiator of synovitis, however, still remains unclear. Future studies should be directed to give light to the pathogenesis of inflammation to better treat or prevent primary FS.

Increased interleukin 1β levels in the subacromial fluid in diabetic patients with rotator cuff lesions compared with nondiabetic patients

BACKGROUND

Diabetic patients have a high prevalence of shoulder pain and stiffness. Interleukin (IL) 1β was reportedly correlated with shoulder stiffness and decreased shoulder function. We retrospectively compared the expression of IL-1β in the subacromial synovial fluid between diabetic and nondiabetic patients with rotator cuff tearing.

MATERIALS AND METHODS

We enrolled 68 patients with rotator cuff tearing (23 diabetic patients and 45 nondiabetic patients). The preoperative sum of range-of-motion deficit (SROMD), Constant score, and visual analog scale (VAS) score were obtained. Intraoperatively, subacromial synovial fluid was collected for the IL-1β level measurement. Comparisons of IL-1β levels, Constant scores, SROMD, and VAS scores between diabetic and nondiabetic patients were analyzed with the Mann-Whitney U test.

RESULT

Diabetic patients with rotator cuff tearing had significantly increased subacromial IL-1β levels (P = .048), SROMD (P < .001) and VAS scores (P = .022) and lower Constant scores (P < .001) than nondiabetic patients. The IL-1β levels in the subacromial fluid were significantly correlated with the Constant score (r = -0.477, P < .001), VAS score (r = 0.698, P < .001), and SROMD (r = 0.293, P = .015) in all patients.

CONCLUSION

The elevated IL-1β levels in the subacromial fluid of patients with diabetes may explain the likelihood of pain and shoulder stiffness developing in these patients. We suggest more aggressive treatment for rotator cuff lesions in diabetic patients.

Association of diabetes mellitus with the risk of developing adhesive capsulitis of the shoulder: a longitudinal population-based followup study

OBJECTIVE

Although it has been suggested that diabetes mellitus (DM) is a risk factor for developing adhesive capsulitis of the shoulder (ACS), data on the temporal association between these 2 conditions are sparse. The purpose of this population-based age- and sex-matched cohort study was to investigate the risk of developing ACS in patients with newly diagnosed DM.

METHODS

A total of 78,827 subjects with at least 2 ambulatory care visits with a principal diagnosis of DM in 2001 were recruited for the DM group. The non-DM group comprised 236,481 age- and sex-matched randomly sampled subjects without DM. The 3-year cumulative risk of ACS was calculated using the Kaplan-Meier method. A Cox proportional hazards regression model was used to estimate the crude and adjusted hazard ratio (HR) of developing ACS.

RESULTS

During a 3-year followup period, 946 subjects (1.20%) in the DM group and 2,254 subjects (0.95%) in the non-DM group developed ACS. The crude HR of developing ACS for the DM group compared to the non-DM group was 1.333 (95% confidence interval [95% CI] 1.236-1.439, P < 0.0001), whereas the adjusted HR was 1.321 (95% CI 1.224-1.425, P < 0.0001) after adjustment for age, sex, and dyslipidemia.

CONCLUSION

This longitudinal population-based followup study showed that there is a significantly increased risk of developing ACS after developing DM.

Clinical effectiveness of bee venom acupuncture and physiotherapy in the treatment of adhesive capsulitis: a randomized controlled trial

BACKGROUND

Bee venom acupuncture (BVA) has been used in the treatment of adhesive capsulitis (AC) in the clinical field. This study aimed to investigate whether the addition of BVA to physiotherapy (PT) would be more effective in the management of AC, and whether BVA would have a dose-dependent effect.

MATERIALS AND METHODS

Sixty-eight patients diagnosed with AC were recruited into 3 groups; BV 1 (1:10,000 BVA plus PT), BV 2 (1:30,000 BVA plus PT), and group 3 (normal saline (NS) injection, as a control, plus PT). PT was composed of 15 minutes of transcutaneous electrical nerve stimulation (TENS), transcutaneous infrared thermotherapy (TDP), and manual PT. Treatments were given in 16 sessions within 2 months. Shoulder pain and disability index (SPADI), pain visual analogue scale (VAS), and 3) active/passive range of motion (ROM) were measured before treatment and at 2, 4, 8, and 12 weeks after the treatment.

RESULTS

All 3 groups showed statistically significant improvements in SPADI, pain VAS scores, and active/passive ROM. The BV 1 group showed significantly better outcomes in SPADI at 8 and 12 weeks, in pain VAS (at rest) at 8 weeks, and in pain VAS (during exercise) at 12 weeks than the NS group. No significant differences were found in active/passive ROM among all the groups.

CONCLUSION

BVA in combination with PT can be more effective in improving pain and function than PT alone in AC. However, the effectiveness of BVA was not shown in a dose-dependent manner.

Matrix metalloproteinase, tissue inhibitor of metalloproteinase and transforming growth factor-beta 1 in frozen shoulder, and their changes as response to intensive stretching and supervised neglect exercise

BACKGROUND

Frozen shoulder is characterized with thickening and contracture of joint capsular. The mechanism of this disorder is not yet clear, however, some proteins have been related to frozen shoulder. This study was to compare the serum levels of proteins related to frozen shoulder, such as matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP) and transforming growth factor-beta (TGF-β) between frozen shoulder and normal subjects; and before and after physical exercise active stretching and gentle thawing in frozen shoulder patients.

METHODS

Serum levels of MMP-1, MMP-2, TIMP-1, TIMP-2, and TGF-β1 was measured from frozen shoulder and normal subjects by using ELISA. Functional assessment of shoulder joint in frozen shoulder patients was based on abbreviated Constant score. Frozen shoulder patients were randomly divided into intensive stretching and supervised neglect groups. Abbreviated Constant score and serum samples of frozen shoulder patients were evaluated at baseline, week-6, and week-12 after exercise, while only baseline serum samples of control were measured. MMP/TIMP ratio was calculated from the total sum of MMP-1 and MMP-2 levels divided by the total sum of TIMP-1 and TIMP-2 levels.

RESULTS

Baseline MMP-1 and MMP-2 levels were significantly lower, while TIMP-1, TIMP-2, and TGF-β1 levels were significantly higher in frozen shoulder group than in control. Increased MMPs and decreased TIMPs were significantly greater after intensive stretching than after supervised neglect exercise. Abbreviated Constant score improvement was significantly higher in intensive stretching group than in supervised neglect group.

CONCLUSIONS

Serum levels of MMP-1, MMP-2, TIMP-1, TIMP-2, and TGF-β1 may be associated to frozen shoulder. Active stretching can improve frozen shoulder better than supervised neglect, as demonstrated by the improvement of Constant score.

Adhesive capsulitis of the knee

The authors describe the case of a 42-year-old woman presenting with significant knee pain and disability. Her imaging findings using contrast MR imaging and FDG PET/CT suggested adhesive capsulitis, which was confirmed by arthroscopy, histology, and the clinical outcome.

Mid-term results following arthroscopic capsular release in patients with primary and secondary adhesive shoulder capsulitis

PURPOSE

The purpose of this study was to assess the effectiveness of arthroscopic capsular release carried out for refractory cases of both primary and secondary adhesive shoulder capsulitis that were not responsive to at least 6 months of prior conservative therapy.

METHODS

Arthroscopic 360-degree capsular release was performed on 167 patients (173 shoulders) with adhesive shoulder capsulitis. Ninety-one shoulders (52.6%) had primary and 82 shoulders (47.4%) secondary adhesive capsulitis. The median follow-up period was 36 months (range 14-67 months).

RESULTS

All patients were evaluated according to the constant score. Both groups (primary and secondary adhesive capsulitis) experienced a significant improvement for all ranges of motion immediately postoperative, as well as at the time of follow-up. The median preoperative constant score was 41 (range 18-61) points and increased significantly to a median of 83 (range 27-100) at the time of follow-up. In the group of primary adhesive capsulitis, median preoperative score was 42 points (range 19-58) and increased to 85 points (range 36-100) at follow-up. In the group of secondary adhesive capsulitis, the preoperative mean increased from 41 points (range 18-61) to 74 points (range 27-100) at the time of the follow-up. The constant score component for pain and the visual analogue scale (VAS) score were also significantly increased.

CONCLUSION

Arthroscopic capsular release in patients with primary and secondary adhesive shoulder capsulitis represents a valuable therapeutic choice with minimal complications, to effectively reduce pain and improve movement in all planes of motion.

LEVEL OF EVIDENCE

Therapeutic retrospective case series study, Level IV.

Inflammatory cytokines are overexpressed in the subacromial bursa of frozen shoulder

BACKGROUND

Frozen shoulder is a debilitating condition characterized by gradual loss of glenohumeral motion with chronic inflammation and capsular fibrosis. Yet its pathogenesis remains largely unknown. We hypothesized that the subacromial bursa may be responsible for the pathogenesis of frozen shoulder by producing inflammatory cytokines.

MATERIALS AND METHODS

We obtained joint capsules and subacromial bursae from 14 patients with idiopathic frozen shoulder and from 7 control subjects to determine the expression levels of interleukin (IL) 1α, IL-1β, IL-6, tumor necrosis factor α (TNF-α), cyclooxygenase (COX) 1, and COX-2 by real-time reverse transcriptase-polymerase chain reaction, immunohistochemistry, and enzyme-linked immunosorbent assay.

RESULTS

IL-1α, IL-1β, TNF-α, COX-1, and COX-2 were expressed at significantly high levels in the joint capsules of the frozen shoulder group compared with those of the control group. Intriguingly, IL-1α, TNF-α, and COX-2 were also expressed at significantly high levels in the subacromial bursae of the frozen shoulder group compared with those of the control group. Immunohistochemical analysis showed increased expression of COX-2 in both the joint capsules and subacromial bursae of the frozen shoulder group.

CONCLUSIONS

These findings imply that elevated levels of inflammatory cytokines in the subacromial bursa may be associated with the pathogenesis of inflammation evolving into fibrosis.

Joint immobilization induced hypoxic and inflammatory conditions in rat knee joints

The purpose of this study was to examine the hypoxic and inflammatory conditions after immobilization in the joint capsule of rat knees. The unilateral knee joints of adult male rats were immobilized with an internal fixator (Im group) for 1 day, 3 days, and 1, 2, 4, 8, and 16 weeks. Sham-operated animals had holes drilled in the femur and tibia and screws inserted without a plate (control group). The number of cells and blood vessels in the capsule were histologically examined. The hypoxic condition in the capsule was histologically examined with a Hypoxyprobe™-1. The gene expressions related to the hypoxic (hypoxia inducible factor-1α, vascular endothelial growth factor, and fibroblast growth factor 2) and inflammatory conditions [interleukin-6 (IL-6), IL-1α, IL-1β, tumor necrosis factor-α, and tumor necrosis factor-β] were evaluated by quantitative reverse transcription polymerase chain reaction. The number of cells was unchanged at 1 day in the two groups; however, the number significantly increased at 3 days in the Im group. The number of blood vessels in the Im group gradually decreased. Strong immunostaining of Hypoxyprobe™-1 around the blood vessels was observed in the Im group. The gene expressions of hypoxia inducible factor-1α and fibroblast growth factor 2 were significantly higher in the Im group compared with those in the control group. The gene expressions of IL-6, IL-1α, IL-1β, and tumor necrosis factor-β were significantly higher in the Im group compared with those in the control group. These data indicated that joint immobilization induced hypoxic and inflammatory conditions in the joint capsule, which might be an initiating factor for joint contracture.

Identification of prognostic factors for the nonoperative treatment of stiff shoulder

PURPOSE

This study evaluated prognostic factors for the nonoperative treatment of stiff shoulder.

METHODS

Between June 2005 and May 2010, 497 stiff shoulders treated at our institute were included in this study. Multivariable analysis for recovery with Cox proportional hazard model was performed. The chief determining variable was pathogenesis (idiopathic, diabetic, post-traumatic) and confounding variables were age (49 or less, 50-59, 60 and above), sex, onset to visit interval (three months or less, four months or more), and external rotation (under 0°, 0° or more) or forward flexion (less than 90°, 90° or more) or internal rotation on the first visit.

RESULTS

There were 356 idiopathic, 61 diabetic, and 80 post-traumatic stiff shoulders. Hazard ratio (HR) and 95 % confidence interval (CI) for recovery (lower HR means poor prognosis) was 0.54 (0.36-0.96) in the diabetic group (p = 0.007), and 0.92 (0.67-1.25) in the post-traumatic group (p = 0.58) compared with the idiopathic group. A positive correlation was observed in ages of 60 or over (HR 1.46, 95 % CI 0.86-1.65, p-value 0.02) and external rotation under 0° on the first visit (0.71, 0.53-0.96, 0.03). No correlations were observed in sex (p = 0.78) or onset to visit interval (p = 0.99). Similar results were obtained when forward flexion or internal rotation was used as a confounding variable.

CONCLUSIONS

Diabetes mellitus and severely restricted joint motion on the first visit were poor prognostic factors and ages of 60 or over was a better prognostic factor.

Benign painful shoulder syndrome: initial results of a single-center prospective randomized radiotherapy dose-optimization trial

BACKGROUND AND PURPOSE

To compare the efficacy of two different dose-fractionation schedules for radiotherapy of patients with benign painful shoulder syndrome.

PATIENTS AND METHODS

Between February 2006 and February 2010, 312 consecutive evaluable patients were recruited for this prospective randomized trial. All patients received radiotherapy with an orthovoltage technique. One radiotherapy course consisted of 6 single fractions in 3 weeks. In case of insufficient remission of pain after 6 weeks, a second radiation series was performed. Patients were randomly assigned to receive either single doses of 0.5 or 1.0 Gy. The endpoint was pain reduction. Pain was measured before, right after, and 6 weeks after radiotherapy using a visual analogue scale (VAS) and a comprehensive pain score (CPS).

RESULTS

The overall response rate for all patients was 83% directly after and 85% 6 weeks after radiotherapy. The mean VAS values before, directly after, and 6 weeks after treatment for the 0.5 and 1.0 Gy groups were 56.8 ± 23.7 and 53.2 ± 21.8 (p = 0.158), 38.2 ± 26.1 and 34.0 ± 24.5 (p = 0.189), and 33.0 ± 27.2 and 23.7 ± 22.7 (p = 0.044), respectively. The mean CPS before, directly after, and 6 weeks after treatment was 9.7 ± 3.0 and 9.5 ± 2.7 (p = 0.309), 6.1 ± 3.6 and 5.4 ± 3.6 (p = 0.096), 5.3 ± 3.7 and 4.1 ± 3.7 (p = 0.052), respectively. Despite a slight advantage in the VAS analysis for the 1.0 Gy group for delayed response, the CPS analysis revealed no statistically significant differences between the two single-dose trial arms for early (p = 0.652) and delayed response quality (p = 0.380).

CONCLUSION

Radiotherapy is an effective treatment option for the management of benign painful shoulder syndrome. Concerning radiation protection, the dose for a radiotherapy series is recommended not to exceed 3-6 Gy.