Hyaluronan modulates cell proliferation and mRNA expression of adhesion-related procollagens and cytokines in glenohumeral synovial/capsular fibroblasts in adhesive capsulitis

Novel MRI signs of the atlantodental space in patients with atlantoaxial dislocation

OBJECTIVES

The type of atlantodental space tissue in patients with atlantoaxial dislocation (AAD) can help doctors understand the possibility of reduction before surgery. However, relevant research on this topic is lacking. In this study, we aimed to summarise the atlantodental space classification of patients with AAD using magnetic resonance imaging (MRI) and explore their clinical characteristics.

MATERIALS AND METHODS

Preoperative 3T cervical MR images of patients who underwent posterior reduction and fixation surgery for non-traumatic AAD between 1 September 2012 and 31 July 2023 were collected. Two radiologists read and recorded the MRI results based on the standard protocol. The kappa value was used to evaluate intra- and inter-observer agreements. The patient's age, sex, body mass index, clinical symptoms, Japanese Orthopaedic Association (JOA) score, and visual analogue scale information were obtained from medical records.

RESULTS

A total of 135 patients with AAD (mean age, 51.3 ± 14.0 years, 52 men) were included in the analysis. The inter-observer agreement between the two readers was 0.818 (P < 0.0001). The intra-observer consistencies were 0.882 (P < 0.0001) and 0.896 (P < 0.0001). Patients with inflexible tissue signs exhibit more irreducible in hyperextension position, and their range of motion of ADI is smaller. These patients were older and had a higher incidence of abnormal spinal cord signals and JOA scores.

CONCLUSIONS

Novel MRI signs exhibited high inter- and intra-observer consistency and were associated with patient age, abnormal spinal cord signals, reducibility, range of motion of ADI, and symptoms.

Can magnetic resonance imaging distinguish clinical stages of frozen shoulder? A state-of-the-art review

Background

Frozen shoulder (FS) is a common disorder causing shoulder pain and limited motion. Magnetic resonance imaging (MRI) is expected to help diagnose FS and realize the disease stage if stage-specific features are present. We aimed to survey stage-related MRI findings of FS in the literature.

Methods

MEDLINE, SCOPUS, and Google Scholar databases were searched with search terms "frozen shoulder" or "adhesive capsulitis" combined with "magnetic resonance imaging." Studies that discussed MRI findings in relation to FS stages were retrieved. The course of FS was divided into stages 1 to 4 according to Hannafin and Chiaia.

Results

Two of the noncontrast-enhanced MRI findings were stage-related. T2 signal hyperintensity of the joint capsule was more frequent in stages 1 and 2. The axillary capsule thickness was greater in stages 1 and 2. However, these findings were also seen in the later stages to a lesser degree. Effusion around the long head of biceps, subcoracoid fat obliteration, and coracohumeral ligament thickening were common in FS but their relation to the stages was not evident. Signal enhancement on contrast-enhanced MRI was not consistently linked to stages.

Conclusion

T2 signal hyperintensity and axillary capsule thickening are characteristic of the early stages of FS, although MRI alone cannot completely define the disease stage.

An injectable thermosensitive hyaluronic acid/pluronic F-127 hydrogel for deep penetration and combination therapy of frozen shoulder

Frozen shoulder (FS) is a common and progressive shoulder disorder that causes glenohumeral joint stiffness, characterized by inflammation and fibrosis. The treatment options are quite limited, and the therapeutic response is hindered by the fibrous membrane formed by excessive collagen and the rapid removal by synovial fluid. To address these challenges, we designed a hyaluronic acid/Pluronic F-127 (HP)-based injectable thermosensitive hydrogel as a drug carrier loaded with dexamethasone and collagenase (HPDC). We screened for an optimal HP hydrogel that can sustain drug release for approximately 10 days both in vitro and in vivo. In the meanwhile, we found that HP hydrogel could inhibit the proliferation and diminish the adhesion capacity of rat synovial cells induced by transforming growth factor-β1. Furthermore, using an established immobilization rat model of FS, intra-articular injection of HPDC significantly improved joint range of motion compared to medication alone. Relying on sustained drug release, the accumulated collagen fibers were degraded by collagenase to promote the deep delivery of dexamethasone. These findings showed a positive combined treatment effect of HPDC, providing a novel idea for the comprehensive treatment of FS.

Cytokines' Role in the Pathogenesis and Their Targeting for the Prevention of Frozen Shoulder: A Narrative Review

Frozen shoulder (FS) is a common name for shoulder movement limitation with different degrees of shoulder rigidity and pain. It is characterized by varying developmental courses, different levels of shoulder movement limitation, and background ambiguity due to the multiplicity of its causative factors. Systemic inflammatory cytokines monitoring and restraining is easy to apply, fast to conduct, and needs lower costs compared to invasive methods for frozen shoulder stage evaluation and early controlling of its progress to the stage that necessitates surgical intervention. The aim of this review was to assess the recent findings concerning the role of cytokines in FS pathogenesis and the possibility of preventing or controlling their progress through targeting these cytokines by the new drugs candidates, such as hyaluronan (HA), botulinum toxin type A (BoNT A), Tetrandrine, tumor necrosis factor-stimulated gene-6 (TSG-6), and cannabidiol. Searching the PubMed site, we encountered out of 1608 records, from which 16 original studies were included for the quantitative construction of this systematic review screening of the recent studies to investigate the different FS pathogenic pathways. Most of the scenarios are centered around the inflammatory and fibrotic process triggered by synovial and capsular fibroblast stimulation. This mechanism depends mainly on alarmins cytokines, including thymic stromal lymphopoietin (TSLP), interleukin-33 (IL-33), and interleukin-25 (IL-25), with the stimulation of interleukin-1 α (IL-1α), interleukin-1 β (IL-1β), tumor necrosis alpha (TNF-α), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in a joint capsule. Different pathways of transforming growth factor- β (TGF-β) stimulation, resulting in overexpression of the fibrotic factors as tenascin C (TNC), fibronectin 1, collagen I (COL 1) and collagen III (COL III), and matrix metalloproteinases (MMPs) in the capsular or synovial/capsular fibroblasts. The overall investigation of these studies led us to conclude that the new drug candidates proved their efficiency in controlling the common pathogenesis of the inflammatory and fibrotic pathways of frozen shoulder and therefore represent a prospect for easy and early controlling and efficiently treating this serious disease.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pathological changes of frozen shoulder in rat model and the therapeutic effect of PPAR-γ agonist

Frozen shoulder is a common shoulder disorder characterized by a gradual increase of pain and a limited range of motion. However, its pathophysiologic mechanisms remain unclear and there is no consensus as to the most effective treatment. The purpose of the study was to investigate the effect of transforming growth factor-β (TGF-β) on fibrosis and inflammatory response of the shoulder joint of rat models and to explore the therapeutic effect of the peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist. In the study, the effect of PPAR-γ agonist CDDO-IM treatment on cell proliferation, migration, and extracellular matrix proteins synthesis (vimentin, α-smooth muscle actin, collagen I, and collagen III) were tested by cell proliferation test, scratches test, real-time quantitative polymerase chain reaction, and Western blot analysis. The frozen shoulder was also established on the rat model by injecting adenovirus-TGF-β1 into rats' shoulder capsule. Pathological changes of the frozen shoulder tissue of the experimental group and PPAR-γ agonist treatment group were evaluated. The stiffness of joints of the three groups was tested. Inflammatory mediators' expression including cyclooxygenase-1, interleukin-1β, and tumor necrosis factor-α of the shoulder was tested by enzyme-linked immunosorbent assay, and the expression of extracellular matrix proteins was evaluated by hematoxylin and eosin staining and immunohistochemistry. The results showed that pathological changes of the frozen shoulder in the rat model include an abnormal proliferation of fibroblasts, infiltration of inflammatory cells, and disorder of fibrous structure, while rosiglitazone reduced the severity of the frozen shoulder in the treatment group. Clinically, PPAR-γ agonists may be a promising target for the treatment of the frozen shoulder.

Frozen Shoulder: A Systematic Review of Cellular, Molecular, and Metabolic Findings

BACKGROUND

Frozen shoulder is a common, poorly understood condition affecting the shoulder joint, with poor long-term outcomes in some in relation to pain and mobility. Understanding the pathophysiology of frozen shoulder at a cellular level and a molecular level may help in the development of novel treatments. The aim of this study was to perform a systematic review of studies examining the cellular, molecular, and metabolic findings in frozen shoulder.

METHODS

A literature search was conducted using Embase, CINAHL (Cumulative Index of Nursing and Allied Health Literature), and PubMed using relevant terms. Studies were included if they assessed cellular, molecular, or metabolic alterations in tissue or blood samples of patients with frozen shoulder.

RESULTS

Of 4,794 studies identified, 25 were included for analysis. Histological findings included nonspecific chronic inflammation and the proliferation of fibroblasts, adipocytes, and blood vessels. Molecular studies showed increased pro-inflammatory mediators, reduced matrix metalloproteinases (MMPs), and increased activity of factors promoting fibroblast activation and nerve growth. Metabolic alterations included an increase in blood lipids.

CONCLUSIONS

Frozen shoulder is thought to occur after a primary insult to the shoulder triggers a complex cascade and upregulation of growth factors and cytokines with an increased turnover of the extracellular matrix, activation of myofibroblasts with deposition of collagen, and reduced matrix degradation. The presence of a background pro-inflammatory state (e.g., patients with diabetes or hyperlipidemia) may exacerbate these abnormalities. Further work assessing patients in early stages of the disease and comparing the inflammatory or fibrogenic characteristics of the shoulder capsule with those of the other joints may help to determine the initiating factors and to explain the predisposition of the shoulder to stiffness.

CLINICAL RELEVANCE

Our findings may form the basis for identifying new targets for the clinical management of frozen shoulder.

The puzzling pathophysiology of frozen shoulders - a scoping review

Purpose

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

Methods

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

Results

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

Conclusion

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

Level of evidence

Level V.

Needle knife therapy plus sodium hyaluronate injection for knee osteoarthritis: A protocol for a systematic review and meta-analysis

BACKGROUND

Knee osteoarthritis (KOA) is a worldwide disease and more and more people are suffered from it. With the increasing number of patients, it brings a huge burden on social economy and security system. There are varieties of methods to cure KOA, such as Traditional Chinese Medicine and surgery. Needle knife therapy plus Sodium hyaluronate Injection is one of the prevalent treatments for KOA. Therefore, we perform a systematic review and meta-analysis to evaluate the evidence for the treatment of needle knife therapy plus sodium hyaluronate Injection.

METHODS

Randomized controlled trials will be used to compare the effect of needle knife therapy plus sodium hyaluronate injection with needle knife alone for KOA patients. Six studies will be included in this meta-analysis, and the relative risk and weight mean difference with 95% CI for the Lysholm knee score, visual analogue scale, and effective rate will be evaluated by using RevMan 5.3 software. Besides, the bias assessment of the included studies will be evaluated using the Cochrane risk of bias tool, and the Grading of Recommendations, Assessment Development, and Evaluation system will be applied to assess the overall quality of the evidence.

RESULTS

From the study we will assess the effectiveness, safety of needle knife therapy plus sodium hyaluronate injection on joint pain relief and functional improvement in patients with KOA.

CONCLUSION

The study will provide a new evidence to confirm the effect of needle knife therapy plus sodium hyaluronate injection on KOA, which can further guide the selection of therapy.

PROSPERO REGISTRATION NUMBER

CRD42020169602.

[Primary (idiopathic) shoulder stiffness : Definition, disease progression, epidemiology and etiology]

Shoulder stiffness is characterized by restriction of the active and passive movement of the glenohumeral joint. The stiffness is ultimately caused by fibrosis and the resulting contracture of the glenohumeral joint capsule and its ligaments; however, the term stiff shoulder is only a descriptive umbrella term that must be further defined as the course of the disease and the recommended treatment are decisively influenced by the cause of the shoulder stiffness. Primary shoulder stiffness, also known as idiopathic shoulder stiffness or "frozen shoulder", must be distinguished from various forms of secondary shoulder stiffness and often occurs in three stages, which can all last for several months to years: the initial "freezing phase", followed by a "frozen phase" and finally a "thawing phase". Although primary shoulder stiffness is a frequent pathological alteration with an prevalence of 2-5% in the general population, the exact etiology remains largely unknown; however, there is consensus throughout the literature that certain systemic pathologies, such as diabetes mellitus are associated with a higher incidence of primary shoulder stiffness.

Enhancement of rotator cuff tendon-bone healing using bone marrow-stimulating technique along with hyaluronic acid

Objective

The purpose of this study was to investigate the effect of hyaluronic acid (HA) in the tendon–bone healing process after rotator cuff repair in a rabbit model.

Methods

In vitro, rat bone marrow stromal cells (rBMSCs) were cultured in media for cartilage-related and inflammation-related gene expression levels examination at 1.0 mg/mL of HA. In vivo, 48 New Zealand white rabbits underwent rotator cuff repair surgery, and they were randomly divided into three groups: (1) control group (n = 16), (2) microfracture (MF) group accepting MF treatment (n = 16) and (3) MF/HA group accepting MF with HA treatment (n = 16). Four rabbits from each group were sacrificed at 6 and 12 weeks postoperatively for histological evaluation and biomechanical testing.

Results

In vitro experiments reveal that HA significantly decreased inflammation-related mRNA expression (IL-1, TNFα) compared with the control group. At 6 weeks after surgery, there was no significant difference of load-to-failure between groups. At 12 weeks after surgery, the mean failure load of the MF/HA group was significantly higher than that of the control group (100.5 ± 10.1 N vs. 68.0 ± 6.2 N; p = 0.0115). The mean failure load of the MF group appeared higher than that of the control group, whereas there was no significant difference (p > 0.05). Histologically, more chondrocytes were clustered at the tendon–bone interface, and more extracellular matrixes were produced in the MF/HA group. The interface of the MF/HA group appeared similar with the normal tendon–bone interface.

Conclusion

HA may play a crucial role in the acceleration of tendon-to-bone healing which might be through inhibiting inflammation. Rotator cuff repair using MF along with HA led to better tendon–bone healing and a subsequent increase of biomechanical strength at the repair site.

The translational potential of this article

HA injection is very common for patients with rotator cuff disease because of its antiinflammatory action and adhesion prevention preoperatively. The HA injection during surgery provides an antiinflammatory effect during tendon–bone healing process and leads to better tendon–bone healing postoperatively.

Hyaluronic Acid Accelerates Tendon-to-Bone Healing After Rotator Cuff Repair

BACKGROUND

There is growing evidence that the subacromial injection of hyaluronic acid (HA) is effective for pain relief in rotator cuff tears; however, its effect on tendon-to-bone healing remains unknown.

PURPOSE

To examine the effect of HA on the chondrogenesis of mesenchymal stem cells (MSCs) in vitro and on tendon-to-bone healing in a rotator cuff repair model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Bilateral complete tears of the infraspinatus tendon were made in rabbits and subsequently repaired. Before closure, 1 mL HA was applied to the repaired site, and phosphate-buffered saline was used in the opposite side as a control. Biomechanical, histological, and immunohistochemical analyses were performed at 4, 8, and 12 weeks after surgery. After euthanizing each animal, the bone marrow was isolated from the femoral bone in the same rabbits. Then, MSCs were cultured in media for chondrogenic differentiation, and the chondral pellet production and cartilage-related gene expression levels in the cells were examined at various concentrations of HA.

RESULTS

At 4 and 8 weeks after surgery, ultimate load-to-failure was significantly greater in the HA group than in the control group (45.61 ± 9.0 N vs 32.42 ± 9.4 N at 4 weeks, 90.7 ± 16.0 N vs 66.97 ± 10.0 N at 8 weeks; both P < .05) but not at 12 weeks after surgery (109.6 ± 40.2 N vs 108.1 ± 42.6 N, P > .05). Linear stiffness was not significant throughout the time point evaluation. The chondroid formation area at the tendon-bone interface stained by safranin O (control vs HA group) was 0.33% ± 0.7% versus 13.5% ± 12.3% at 4 weeks after surgery ( P < .05) and 3.0% ± 5.9% versus 12.9% ± 12.9% at 8 weeks after surgery ( P < .05), but there was no significant difference at 12 weeks after surgery. Maturity of collagen at the repaired site stained by PicroSirius Red (control vs HA group) was 16.2 ± 10.6 versus 43.5 ± 21.3 at 4 weeks after surgery ( P < .05), but there were no significant differences at 8 and 12 weeks after surgery. MSCs were cultured in media for chondrogenic differentiation, and the chondral pellet production and cartilage-related gene expression levels in the cells were examined at various concentrations of HA. The number of CD44-positive cells (control vs HA group) was 8.3% ± 1.4% versus 26.2% ± 5.2% at 3 days after surgery ( P < .05), 1.8% ± 1.1% versus 26.6% ± 11.6% at 4 weeks after surgery ( P < .05), 0.6% ± 0.9% versus 0.5% ± 0.6% at 8 weeks after surgery ( P > .05), and 1.8% ± 4.0% versus 5.4% ± 4.2% at 12 weeks after surgery ( P > .05). Compared with the control group, HA significantly increased the volume of cartilaginous pellet produced by MSCs (0.0016 ± 0.0015 mm³ at 0 mg/mL of HA, 0.0041 ± 0.0023 mm³ at 1.0 mg/mL, and 0.0041 ± 0.0018 mm³ at 4.0 mg/mL), with increased mRNA expression (relative ratio to control) of type 2 collagen (1.34 ± 0.38), SOX9 (1.58 ± 0.31), and aggrecan (1.30 ± 0.22) genes in the pellet ( P < .01).

CONCLUSION

HA accelerated tendon-to-bone healing in the rotator cuff repair model, enhancing the biomechanical strength and increasing chondroid formation and tendon maturity at the tendon-bone interface. Based on the data of in vitro experiments, HA-activated MSCs may play a crucial role in the acceleration of tendon-to-bone healing.

CLINICAL RELEVANCE

The data suggest the relevance of clinical application of HA to accelerate tendon-to-bone healing. It may decrease the number of retears after surgery.

High-molecular-weight hyaluronic acid attenuated matrix metalloproteinase-1 and -3 expression via CD44 in tendinopathy

Evidence indicates that hyaluronic acid (HA) mitigates tendinopathy, but the effect of molecular weight is unclear. We investigated the effects of different concentrations and different molecular weights of HA (350 kDa, 1500 kDa, and 3000 kDa) on matrix metalloproteinase (MMP)-1 and -3 expression in IL-1β-stimulated rat tenocytes, and on their dynamic expression in peritendinous effusion from patients with long head of biceps (LHB) tendinopathy after high-molecular-weight (HMW)-HA treatments. Reverse transcription PCR, real-time PCR, and ELISA were used to determine MMP-1 and -3expression. Because CD44 was clearly expressed in the plasma membranes of cultured tenocytes, OX-50, a CD44 antagonist, was used to inhibit CD44 to evaluate the HA mechanism. HA (3000 kDa) significantly (p < 0.001) downregulated the mRNA and protein expression of MMP-1 and -3 in IL-1β-stimulated tenocytes. Its attenuating effects were dose-dependent (p < 0.01). In OX-50-pretreated cells, the mRNA expression of CD44 was not significantly altered, but the mRNA expression of MMP-1 and -3 was significantly upregulated. Visual analogue scale scores were significantly lower, and MMP-1 and -3 expression was significantly (p < 0.05) lower one month posttreatment. HMW-HA attenuated tendinopathy by downregulating MMP-1 and -3 expression. Inhibiting CD44 blocked the effects of HMW-HA.

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.

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.

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.

Ultrasound investigation of the glenohumeral joint by anterior access in patients with rheumatoid arthritis and healthy controls

BACKGROUND

The aim of this study was to measure glenohumeral joint (GHJ) parameters via the anterior access through ultrasound and to compare to data from posterior and inferior accesses.

MATERIAL AND METHODS

Twenty healthy controls (M: F=15: 5, aged 45.1±11.2 years) and 16 patients (M: F=5: 11, aged 54.6±14.7 years) with active rheumatoid arthritis (RA) (DAS 28 4.6±1.2) were investigated (SonoSite-Titan). To make the GHJ visible on the anterior access, we used the original GHJ opening maneuver. The GHJ width was measured for every transducer position at 2 points. The positions were: posterior transversal, inferior longitudinal, anterior longitudinal along the articular line, anterior transversal upper, middle and lower. The joint width included thickness of cartilage plus synovial fluid/pannus. Rotator interval (RI) width and height (upper biceps channel) were measured.

RESULTS

Our normal GHJ values by posterior and inferior accesses were within previously estimated values (<2 mm and <3 mm, respectively). We acquired the first values of GHJ width from the anterior access. The last were within a range of 0.7-1.7 mm for healthy controls. Patients with RA showed significantly enlarged joint cavities. RI was not inflamed. Posterior and inferior data of GHJ width were significantly correlated (p=0.01). The data did not correlate with anterior values (p=+0.44, p=-0.56). Synovitis was much more prominent in posterior, upper anterior transversal, and anterior longitudinal accesses.

CONCLUSIONS

The GHJ may be visualized by anterior access using a special maneuver. Synovitis in the anterior region of the GHJ may develop at an independent rate. Anterior GHJ sonography may be complementary to the classic access.

PXL01 in sodium hyaluronate for improvement of hand recovery after flexor tendon repair surgery: randomized controlled trial

Background

Postoperative adhesions constitute a substantial clinical problem in hand surgery. Fexor tendon injury and repair result in adhesion formation around the tendon, which restricts the gliding function of the tendon, leading to decreased digit mobility and impaired hand recovery. This study evaluated the efficacy and safety of the peptide PXL01 in preventing adhesions, and correspondingly improving hand function, in flexor tendon repair surgery.

Methods

This prospective, randomised, double-blind trial included 138 patients admitted for flexor tendon repair surgery. PXL01 in carrier sodium hyaluronate or placebo was administered around the repaired tendon. Efficacy was assessed by total active motion of the injured finger, tip-to-crease distance, sensory function, tenolysis rate and grip strength, and safety parameters were followed, for 12 months post-surgery.

Results

The most pronounced difference between the treatment groups was observed at 6 months post-surgery. At this timepoint, the total active motion of the distal finger joint was improved in the PXL01 group (60 vs. 41 degrees for PXL01 vs. placebo group, p = 0.016 in PPAS). The proportion of patients with excellent/good digit mobility was higher in the PXL01 group (61% vs. 38%, p = 0.0499 in PPAS). Consistently, the PXL01 group presented improved tip-to-crease distance (5.0 vs. 15.5 mm for PXL01 vs. placebo group, p = 0.048 in PPAS). Sensory evaluation showed that more patients in the PXL01 group felt the thinnest monofilaments (FAS: 74% vs. 35%, p = 0.021; PPAS: 76% vs. 35%, p = 0.016). At 12 months post-surgery, more patients in the placebo group were considered to benefit from tenolysis (30% vs. 12%, p = 0.086 in PPAS). The treatment was safe, well tolerated, and did not increase the rate of tendon rupture.

Conclusions

Treatment with PXL01 in sodium hyaluronate improves hand recovery after flexor tendon repair surgery. Further clinical trials are warranted to determine the most efficient dose and health economic benefits.

Trial Registration

ClinicalTrials.gov NCT01022242; EU Clinical Trials 2009-012703-25.

A hexadecylamide derivative of hyaluronan (HYMOVIS®) has superior beneficial effects on human osteoarthritic chondrocytes and synoviocytes than unmodified hyaluronan

Background

Intra-articular hyaluronan (HA) injection provides symptomatic benefit in the treatment of osteoarthritis (OA). Previously we found superior beneficial effects in a large animal OA model of a hexadecylamide derivative compared with unmodified HA of the same initial molecular weight. The current study sought to define possible molecular mechanisms whereby this enhanced relief of symptoms was occurring.

Methods

Chondrocytes and synovial fibroblasts were isolated from tissues of patients undergoing arthroplasty for knee OA. Monolayer cultures of cells were treated with 0, 0.5, 1.0 or 1.5 mg/mL of unmodified HA (500–730 kDa) or a hexadecylamide derivative of HA of the same initial molecular weight (HYADD4®-G; HYMOVIS®) simultaneously or 1 hour before incubation with interleukin (IL)-1beta (2 ng/mL). Cultures were terminated 15 or 30 minutes later (chondrocytes and synovial fibroblasts, respectively) for quantitation of phosphorylated-(p)-JNK, p-NFkappaB, p-p38, or at 24 hours for quantitation of gene expression (MMP1 &13, ADAMTS4 &5, TIMP1 &3, CD44, COL1A1 &2A1, ACAN, PTGS2, IL6, TNF) and matrix metalloproteinase (MMP)-13 activity.

Results

The hexadecylamide derivative of HA had significantly better amelioration of IL-1beta-induced gene expression of key matrix degrading enzymes (MMP1, MMP13, ADAMTS5), and inflammatory mediators (IL6, PTGS2) by human OA chondrocytes and synovial fibroblasts. Pre-incubation of cells with the derivatized HA for 1 hour prior to IL-1beta exposure significantly augmented the inhibition of MMP1, MMP13, ADAMTS4 and IL6 expression by chondrocytes. The reduction in MMP13 mRNA by the amide derivative of HA was mirrored in reduced MMP-13 protein and enzyme activity in IL-1beta-stimulated chondrocytes. This was associated in part with a greater inhibition of phosphorylation of the cell signalling molecules JNK, p38 and NF-kappaB.

Conclusions

The present studies have demonstrated several potential key mechanisms whereby the intra-articular injection of a hexadecylamide derivative of HA may be acting in joints with OA.

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.

Collagen production at the edge of ruptured rotator cuff tendon is correlated with postoperative cuff integrity

PURPOSE

The purpose was to evaluate the correlation between messenger RNA (mRNA) expression of collagen at the edge of the ruptured rotator cuff tendon and postoperative cuff integrity.

METHODS

The edge of the ruptured tendon was sampled during open rotator cuff surgery in 12 patients with full-thickness rotator cuff tears (mean age, 58.2 years). The mean period from symptom onset was 9.3 months (range, 1 to 36 months), and the mean tear size was 4.1 cm. As controls, rotator cuff tendons with no gross rupture were taken from 5 fresh cadavers. Production of type I and type III collagen was examined by real-time reverse transcription polymerase chain reaction. By use of magnetic resonance imaging, postoperative cuff integrity was evaluated based on the classification of Sugaya et al. and then scored, ranging from 5 points for type I to 1 point for type V.

RESULTS

Looking at the mRNA of type I and type III collagen in tendons, we found that the expression of mRNA for both collagen types in ruptured tendons was significantly greater than in control tendons (P = .0462 for type I collagen and P = .0306 for type III collagen). Correlating the mRNA of type I and type III collagen with repaired cuff integrity on postoperative magnetic resonance imaging, we found a close relation between expression of mRNA for both collagen types and postoperative rotator cuff integrity (r = 0.63 [P = .038] for type I collagen and r = 0.626 [P = .03] for type III collagen). Furthermore, expression of type I collagen mRNA showed a significant inverse correlation with the period from symptom onset (r = -0.845, P < .0005).

CONCLUSIONS

This study showed that expression of mRNA for type I and type III collagen at the edge of the ruptured rotator cuff tendon was significantly correlated with postoperative cuff integrity and that mRNA expression for type I collagen was significantly associated with the period from symptom onset. These results may suggest that conservative treatment should not be prolonged if patients do not respond within a certain period.

LEVEL OF EVIDENCE

Level III, prognostic case-control study.

Adhesive capsulitis of the shoulder

Adhesive capsulitis is characterized by painful, gradual loss of active and passive shoulder motion resulting from fibrosis and contracture of the joint capsule. Other shoulder pathology can produce a similar clinical picture, however, and must be considered. Management is based on the underlying cause of pain and stiffness, and determination of the etiology is essential. Subtle clues in the history and physical examination can help differentiate adhesive capsulitis from other conditions that cause a stiff, painful shoulder. The natural history of adhesive capsulitis is a matter of controversy. Management of true capsular restriction of motion (ie, true adhesive capsulitis) begins with gentle, progressive stretching exercises. Most patients improve with nonsurgical treatment. Indications for surgery should be individualized. Failure to obtain symptomatic improvement and continued functional disability following ≥6 months of physical therapy is a general guideline for surgical intervention. Diligent postoperative therapy to maintain motion is required to minimize recurrence of adhesive capsulitis.

Hyaluronan modulates proliferation and migration of rabbit fibroblasts derived from flexor tendon epitenon and endotenon

PURPOSE

There is a growing body of evidence supporting the use of hyaluronan (HA) for treatment of injured tendons, although the mechanism of the healing effect has not yet been clarified. We therefore investigated the effects of HA on the proliferation and migration of tendon fibroblasts derived from rabbit flexor tendon epitenon and endotenon.

METHODS

From explanted rabbit intrasynovial flexor tendons (n = 5), we cultured tendon fibroblasts derived from the epitenon and endotenon. CD44 expression on the tendon fibroblasts was detected by flow cytometric analysis. Various concentrations of HA (0.1-5.0 mg/mL) were added to monolayer-cultured tendon fibroblasts. We evaluated cell proliferation by recording changes in cell number, and measured cell migration by wound-healing assay.

RESULTS

Flow cytometric analysis detected CD44 expression on the tendon fibroblasts. Treatment with HA at various concentrations notably and dose dependently inhibited cell proliferation and promoted cell migration.

CONCLUSIONS

Hyaluronan modulates the proliferation and migration of rabbit fibroblasts derived from the flexor tendon epitenon and endotenon.