Interleukin-1-induced glenohumeral synovitis and shoulder pain in rotator cuff diseases

Clinical Implication of Glenohumeral and Subacromial Synovitis in Rotator Cuff Tears

Background

Synovitis of the glenohumeral (GH) joint and the subacromial (SA) space is commonly observed during arthroscopic rotator cuff surgery.

Purpose

To investigate the distribution, severity, and clinical implications of synovitis in the GH joint and SA space in patients with a full-thickness rotator cuff tear (RCT).

Study Design

Case series; Level of evidence, 4.

Methods

Data were retrospectively collected from 207 patients with a full-thickness RCT who underwent arthroscopic repair. Preoperative parameters used in the clinical assessment included pain, range of motion (ROM), muscle strength, and functional scores. Macroscopic assessment of synovitis was performed intraoperatively in the 3 regions of interest (ROIs) of the GH joint and 4 ROIS of the SA space using an evaluation system. The distribution and severity of synovitis and the association between synovitis and clinical assessment were evaluated.

Results

Synovitis was more severe in the GH joint than in the SA space (P < .001). Synovitis in the posterior GH joint and the lateral SA space, where most of the rotator cuff was located, was the most severe area among the ROIs of the GH joint and the SA space, respectively (P < .05). All types of pain, except for pain at rest, were associated with synovitis in the posterior GH joint (P < .05). All ROM measures were associated with synovitis in the posterior and inferior GH joint (|r| > 0.20; P < .05 for both). The strength of the supraspinatus and the infraspinatus was associated with synovitis in the posterior GH joint (P < .05). Shoulder function was associated with synovitis in the posterior and inferior GH joint and more in the posterior GH joint (P < .05 for both). Synovitis in the SA space was not associated with any of the clinical parameters.

Conclusion

Synovitis in the posterior GH joint was the most severe form of synovitis in the GH joint in patients with a full-thickness RCT. Synovitis in the posterior GH joint was closely associated with increased pain and decreased ROM, muscle strength, and functional score. Synovitis in the SA space was milder and not associated with any clinical parameters.

Expression of Apelin in Rotator Cuff Tears and Examination of Its Regulatory Mechanism: A Translational Study

OBJECTIVES

Inflammatory mediators play important roles in the pain associated with rotator cuff tears (RCTs), but their underlying mechanisms are unclear. Apelin, a neuropeptide, is upregulated under inflammatory conditions and possibly contributes to pain induced by rotator cuff tears. This translational study aimed to examine apelin expression and regulation by tumor necrosis factor alpha (TNF-α) in patients with RCT and in rat RCT models.

METHODS

Synovial tissues were harvested from the glenohumeral joints of the shoulders in 46 patients who underwent arthroscopic Bankart repair for recurrent shoulder dislocations (RSDs) or arthroscopic rotator cuff repair for RCTs. The harvested tissues were extracted and processed by reverse transcriptase-polymerase chain reaction (RT-PCR). Rats underwent sham or RCT surgery; the rotator cuff tissues were extracted 1, 7, 14, 28, and 56 days after surgery and analyzed for mRNA expression levels of the TNF-α and apelin using RT-PCR. The cultured rotator cuff cells (RCCs) were stimulated with TNF-α to examine their role in the regulation of apelin expression.

RESULTS

Apelin expression was higher in the RCT group than in the RSD group and significantly correlated with pain intensity. In rats, the expression was also higher in RCT. Apelin expression significantly increased during the acute and chronic phases in rats.

CONCLUSIONS

In cultured RCCs, apelin mRNA levels significantly increased after TNF-α stimulation. Apelin levels were regulated by TNF-α and were highly expressed in patients with RCT and rats in RCT models. Thus, apelin may be a new pain management target for RCTs.

Expression and distribution pattern of aggrecanases and miR-140s in the thickened synovia of shoulder joints in rotator cuff tears: A retrospective observational study

The rotator cuff (RC) is frequently torn at the enthesis composed of fibrocartilage. We aimed to histopathologically evaluate lining layers and assess the distribution of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)4, ADAMTS5, and microRNA (miR)-140s in the synovia of patients with RC tears. We recruited 51 patients who underwent arthroscopic surgical treatment for full-thickness rotator cuff tears, including 26 patients with < 3 cm tear size (group N) and 25 patients with ≥ 3 cm tear size (group W). Biopsied synovia were analyzed using histological and immunohistological techniques for the presence ADAMTS4 and ADAMTS5. The layers of the synovial lining were morphologically classified into 3 grades according to the synovitis score and staining levels of ADAMTSs. The glenohumeral synovia from 8 patients with recurrent shoulder dislocation (group C) were used as controls. Furthermore, in situ hybridization was performed to evaluate the presence of miR-140s in patients with massive tears and recurrent shoulder dislocation. The staining levels were evaluated and analyzed based on comparison between patient groups and correlation between ADAMTS5 and miR-140s. Histological analysis revealed significant differences between groups W and C. ADAMTS5 and ADAMTS4 were strongly expressed in the synovial lining of patients in group W, and this expression was significantly higher than that in groups C and N. In addition, expression of ADAMTS5 was inversely correlated with that of miR-140-3p. This study showed that synovia from group W had a significantly higher rate of severely thickened areas with strong expression of both aggrecanases. Furthermore, the area with weak expression of miR-140-3p showed strong ADAMTS5 expression.

Biomolecules Related to Rotator Cuff Pain: A Scoping Review

The pathophysiology of pain in patients suffering from rotator cuff (RC) tendinopathy or tears has been examined in various ways. Several molecules from tissue samples taken from the subacromial bursa, supraspinatus tendon, glenohumeral joint fluid, and synovium as well as from peripheral blood have been investigated. This article explores these studies, the assessed biomarkers, and groups their results according to the status of tendon integrity (tendinopathy or tear). Through a structured PubMed database search, 9 out of 658 articles were reviewed. Interleukins, mostly IL-1b and its antagonist, IL-1ra, matrix Metalloproteinases (MMPs), the vascular endothelial growth factor (VEGF) and TNF-a are biomarkers directly searched for correlation to pain level. Most studies agree that IL-1b is directly positively correlated to the degree of pain in patients with RC tendinopathy, especially when the examined sample is taken from the subacromial bursa. VEGF, and TNF-a have been related to shoulder pain preoperatively and TNF-a has also been linked with sleep disturbance. Further studies pointing to more biomarkers taken from the subacromial bursa or tendon directly relating to pain degree are warranted.

Blood Flow in the Anterior Humeral Circumflex Artery Reflects Synovial Inflammation of the Shoulder Joint in Rotator Cuff Tears

Background

An association has been reported between rotator cuff tear and inflammation. We hypothesized that blood flow in the anterior humeral circumflex artery would reflect synovial inflammation in the shoulder. This study aimed to clarify the association of blood flow in the anterior humeral circumflex artery with synovial inflammation and shoulder pain in patients with rotator cuff tears.

Methods

In this prospective, cross-sectional study, tissue samples from the synovium in the rotator interval were obtained from 33 patients undergoing arthroscopic rotator cuff repair. Reverse transcription-polymerase chain reaction and real-time polymerase chain reaction were performed to determine the messenger RNA expression of inflammatory mediators, growth factors, and matrix metalloproteinases. Additional tissue samples were fixed for histologic evaluation. Before surgery, we measured the peak systolic velocity in the anterior humeral circumflex artery using pulse Doppler ultrasonography.

Results

The peak systolic velocity in the anterior humeral circumflex artery was positively correlated with the messenger RNA expression of interleukin 1β, interleukin 8, and matrix metalloproteinase 3 genes (r = 0.49, P = .004; r = 0.55, P = .001; and r = 0.39, P = .026, respectively), as well as histologic synovitis scores (r = 0.48, P = .005). Additionally, it was significantly higher in patients with resting pain than in those without resting pain (P = .048).

Conclusion

The peak systolic velocity in the anterior humeral circumflex artery is associated with the severity of synovial inflammation. Our results suggest that assessing the peak systolic velocity in the anterior humeral circumflex artery is useful for evaluating the severity of synovial inflammation.

The Usefulness of Serological Inflammatory Markers in Patients with Rotator Cuff Disease-A Systematic Review

Background and Objectives: Rotator cuff disease (RCD) is a prominent musculoskeletal pain condition that spans a variety of pathologies. The etiology and precise diagnostic criteria of this condition remain unclear. The current practice of investigating the biochemical status of RCD is by conducting biopsy studies but their invasiveness is a major limitation. Recent biochemical studies on RCD demonstrate the potential application of serological tests for evaluating the disease which may benefit future clinical applications and research. This systematic review is to summarize the results of available studies on serological biochemical investigations in patients with RCD. Methods: An electronic search on databases PubMed and Virtual Health Library was conducted from inception to 1 September 2021. The inclusion criteria were case-control, cross-sectional, and cohort studies with serological biochemical investigations on humans with RCD. Methodological quality was assessed using the Study Quality Assessment Tool for Observational Cohort and Cross-sectional studies from the National Heart, Lung, and Blood Institute. Results: A total of 6008 records were found in the databases; of these, 163 full-text studies were checked for inclusion and exclusion criteria. Nine eligible studies involving 984 subjects with RCD emerged from this systematic review. The quality of the studies found ranged from poor to moderate. In summarizing all the studies, several fatty acids, nonprotein nitrogen, interleukin-1 β, interleukin-8, and vascular endothelial growth factor were found to be significantly higher in blood samples of patients with RCD than with control group patients, while Omega-3 Intex, vitamin B12, vitamin D, phosphorus, interleukin-10, and angiogenin were observed to be significantly lower. Conclusions: This is the first systematic review to summarize current serological studies in patients with RCD. Results of the studies reflect several systemic physiological changes in patients with RCD, which may prove helpful to better understand the complex pathology of RCD. In addition, the results also indicate the possibility of using serological tests in order to evaluate RCD; however, further longitudinal studies are required.

Subacromial Bursa: A Neglected Tissue Is Gaining More and More Attention in Clinical and Experimental Research

The subacromial bursa has long been demolded as friction-reducing tissue, which is often linked to shoulder pain and, therefore, partially removed during shoulder surgery. Currently, the discovery of the stem cell potential of resident bursa-derived cells shed a new light on the subacromial bursa. In the meanwhile, this neglected tissue is gaining more attention as to how it can augment the regenerative properties of adjacent tissues such as rotator cuff tendons. Specifically, the tight fibrovascular network, a high growth factor content, and the large progenitor potential of bursa-derived cells could complement the deficits that a nearby rotator cuff injury might experience due to the fact of its low endogenous regeneration potential. This review deals with the question of whether bursal inflammation is only a pain generator or could also be an initiator of healing. Furthermore, several experimental models highlight potential therapeutic targets to overcome bursal inflammation and, thus, pain. More evidence is needed to fully elucidate a direct interplay between subacromial bursa and rotator cuff tendons. Increasing attention to tendon repair will help to guide future research and answer open questions such that novel treatment strategies could harvest the subacromial bursa's potential to support healing of nearby rotator cuff injuries.

Serum Levels of TNF-α Are Increased in Patients with Rotator Cuff Tear and Sleep Disturbance

The purpose of this study was to determine serum levels of sleep-related cytokines in patients with rotator cuff tear (RCT) who were experiencing pain-related sleep disturbance. Peripheral blood samples before surgery were collected from 63 study participants and divided into three groups: RCT with sleep disturbance group; SD group (n = 21), RCT with normal sleep group; NS group (n = 21), and patients with chronic shoulder instability; control group (n = 21). Serum concentration levels of interleukin-1α (IL-1α), IL-1β, IL-2, IL-6, IL-8, IL-10, and tumor necrosis factor-α (TNF-α) were measured via ELISA. The associations between serum levels of sleep-related cytokines and clinical scores and the Pittsburgh Sleep Quality Index (PSQI) were analyzed. Serum concentration levels of TNF-α were significantly higher in the SD group compared with those of the NS and control groups (p = < 0.001 and 0.05). Serum levels of IL-8 and IL-10 were significantly higher in the SD group compared with those of control group (p = 0.01 and = 0.05), but did not differ significantly from that of the NS group. There were no associations between serum levels of sleep-related cytokines and all clinical scores. The current findings suggest that TNF-α may be associated with sleep disturbance in patients with RCT.

Chronicity is associated with the glenohumeral synovitis in patients with a rotator cuff tear

Synovitis of the glenohumeral joint (GHJ) and subacromial space (SAS) is one of the most common findings during arthroscopic rotator cuff repair (RCR). The purpose of this study is to determine clinical factors associated with the degree of synovitis in patients with a rotator cuff tear and whether macroscopic synovitis affects early clinical outcomes following arthroscopic RCR. Arthroscopic videos of 230 patients treated with arthroscopic RCR were randomly reviewed by two experienced shoulder surgeons. The synovitis scores of the GHJ using Davis's grading system and the SAS using Jo's grading system were rated with a consensus. Univariate and multivariate analyses were used to identify the associations between the synovitis scores and various parameters, including demographics, preoperative, and postoperative clinical outcomes. Univariate analyses revealed that age, side, body mass index, duration of symptoms, preoperative stiffness, diabetes, muscle atrophy, fatty infiltration, tear size, preoperative clinical scores, and preoperative range of motion were significantly associated with the GHJ synovitis score (all p < 0.05). Multivariate analyses revealed that the duration of symptoms, tear size, and diabetes was significantly associated with the GHJ synovitis score (p = 0.048, p = 0.025, p = 0.011, respectively). Longer duration of symptoms, larger tear size, and the presence of diabetes was independently associated with increased GHJ synovitis in patients with a rotator cuff tear. These results suggest that GHJ synovitis might be more involved in the pathogenesis for pain and tear progression of rotator cuff disease compared with SAS synovitis.

Effectiveness of video-based rehabilitation program on pain, functionality, and quality of life in the treatment of rotator cuff tears: A randomized controlled trial

BACKGROUND

Video-based rehabilitation programs, which are also used in the treatment of neurological disorders, could be a beneficial treatment option for patients who cannot receive treatment.

PURPOSE

To determine the efficacy of video-based rehabilitation program in the conservative treatment of partial rotator cuff tears in comparison to a physiotherapist-supervised rehabilitation program.

STUDY DESIGN

A randomized controlled clinical trial.

METHODS

Thirty-three voluntary patients with partial rotator cuff tear were randomized into two groups: video-based rehabilitation (VBR) group and physiotherapist-supervised rehabilitation (PSR) group, for a common 6 weeks rehabilitation program. After drop outs, thirty participants (mean ± SD age, 50.60 ± 8.54 years; 10 female) were finally completed the trial. Active shoulder range of motion, pain, functional status, and health-related quality of life of the patients were assessed before and after treatment. Also, treatment satisfaction level was assessed at the end of the treatment.

RESULTS

There was statistically significant improvement in terms of active shoulder range of motion values (mean differences at 95% confidence interval for abduction: 30.75-51.37 in the VBR group, 34.20-54.45 in the PSR group, P = .001 in both groups) and secondary outcome measures within both groups (P < .05). However, there were no statistically significant differences in terms of all outcome measures between groups (P > .05). The level of satisfaction from treatment in the PSR group was higher than that in the VBR group.

CONCLUSION

A video-based rehabilitation program is an effective option in terms of shoulder range of motion, pain, functionality, and quality of life and has a comparable success level with a PSR program in the conservative treatment of partial rotator cuff tears.

Correlation between Severity of Synovitis and Clinical Features in Rotator Cuff Tears

Background

Rotator cuff tears can be asymptomatic in some cases; however, even when the tear size is small, clinical symptoms can be very severe. This suggests that symptoms of rotator cuff tears are related to factors other than the size. Although synovitis has been cited as one of the factors, there is no grading system for synovitis in rotator cuff tears. Moreover, there are few studies that evaluated the relationship between synovitis and clinical features in patients with rotator cuff tears.

Methods

Patients with medium-sized rotator cuff tears, who were scheduled for arthroscopic repair, were recruited for this study. The glenohumeral joint was divided into 4 quarters. Then, vascularity and hypertrophy of the joint were graded in each quarter using a modified scoring system. Clinical assessment was performed preoperatively and at 3 months and 6 months after surgery. Finally, correlation between the severity of synovitis and clinical features was analyzed.

Results

The intraobserver correlation coefficient was 0.815 to 0.918 and the interobserver correlation coefficient was 0.779 to 0.992 for the single measurement. Vascularity was significantly correlated with the range of motion, strength, and constant score within 6 months after surgery. Hypertrophy was correlated with the range of motion within 6 months after surgery.

Conclusions

Synovitis in the shoulder with rotator cuff tears can be graded by using our modified scoring system. The severity of synovitis was closely related to the clinical features after surgery. Therefore, when treating patients with rotator cuff tears, treatment of synovitis should also be considered.

Increased levels of inflammatory markers in the subscapularis tendon and joint capsule in patients with subacromial impingement

PURPOSE

To analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with subacromial impingement syndrome and compare them with samples from male patients with post-traumatic recurrent shoulder instability, to detect increased inflammatory activity that might be present inside the humeroscapular joint.

METHODS

Twenty male patients scheduled for surgery for either subacromial decompression or Bankart reconstruction were included. Four biopsies from each patient were obtained during surgery from the capsule and the subscapularis tendon. Each specimen was analyzed for TNF-α, IL-6, CD-3 and CD-72. Multiplex fluorescence immunohistochemistry was performed on histological samples from the capsule and tendon to demonstrate the level of inflammatory markers. Fluorescence microscope images were acquired using an automated scanning system. On each slide, the number of pixels was registered and used in the analyses.

RESULTS

The subacromial impingement syndrome group comprised eight patients, median age 53 (45-74) years, while the instability group 12, median age 27 (22-48) years (p < 0.00001). The amount of IL-6 and TNF-α was significantly higher in the subscapularis tendon of the patients with subacromial impingement syndrome compared with instability patients (p = 0.0015 and p = 0.0008 respectively). In the capsular samples, significantly higher amount of TNF-α and CD-72 was found in patients with subacromial impingement syndrome compared with instability patients (p < 0.0001 for both). On the other hand, the amount of CD-3 was significantly higher in the instability group (p = 0.0013).

CONCLUSIONS

This study provides evidence that an extended inflammatory process is present, not only in the subacromial bursa but also in the glenohumeral joint in patients with subacromial impingement syndrome.

LEVEL OF EVIDENCE

Level III.

CLINICAL RELEVANCE

To develop a treatment targeted towards intra-articular inflammatory cytokines appears appealing.

Bone marrow mesenchymal stem cell-derived exosomes promote rotator cuff tendon-bone healing by promoting angiogenesis and regulating M1 macrophages in rats

BACKGROUND

Rotator cuff tears (RCTs) often require reconstructive surgery. Tendon-bone healing is critical for the outcome of rotator cuff reconstruction, but the process of tendon-bone healing is complex and difficult. Mesenchymal stem cells (MSCs) are considered to be an effective method to promote tendon-bone healing. MSCs have strong paracrine, anti-inflammatory, immunoregulatory, and angiogenic potential. Recent studies have shown that MSCs achieve many regulatory functions through exosomes. The purpose of this study was to explore the role of bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) in tendon-bone healing.

METHODS

Our study found that BMSC-Exos promote the proliferation, migration, and angiogenic tube formation of human umbilical vein endothelial cells (HUVECs). The mechanism by which BMSC-Exos achieve this may be through the regulation of the angiogenic signaling pathway. In addition, BMSC-Exos can inhibit the polarization of M1 macrophages and inhibit the secretion of proinflammatory factors by M1 macrophages. After rotator cuff reconstruction in rats, BMSC-Exos were injected into the tail vein to analyze their effect on the rotator cuff tendon-bone interface healing.

RESULTS

It was confirmed that BMSC-Exos increased the breaking load and stiffness of the rotator cuff after reconstruction in rats, induced angiogenesis around the rotator cuff endpoint, and promoted growth of the tendon-bone interface.

CONCLUSION

BMSC-Exos promote tendon-bone healing after rotator cuff reconstruction in rats by promoting angiogenesis and inhibiting inflammation.

Decreased Synovial Fluid Biomarkers Levels Are Associated with Rehabilitation of Function and Pain in Rotator Cuff Tear Patients Following Electroacupuncture Therapy

Background

The aim of this study was to assess inflammatory cytokines levels in synovial fluid (SF) before and after electroacupuncture (EA) treatment and to explore whether these biomarkers are associated with function of rotator cuff tear (RCT) patients.

Material/Methods

We recruited 54 patients with RCT and separated them into an EA group and a control group. The SF biomarker levels were detected at baseline and at 6-week and 6-month follow-up. The symptomatic severity was evaluated by visual analog scale (VAS), Constant-Murley score, and American Shoulder and Elbow Surgeons score (ASES). We also investigated the correlation between symptomatic severity and biomarker levels in SF of the shoulder joint.

Results

The reductions in VAS and improved functional score (ASES and Constant-Murley score) were significantly different between the 2 groups, and SF biomarker concentrations were significantly lower in the EA group. IL-1β levels were significantly negatively correlated with Constant-Murley score (r=−0.73, P=0.04) and ASES score (r=−0.59, P<0.001) and positively correlated with VAS scores (r=0.81, P=0.004). IL-6 levels were significantly negatively correlated with Constant-Murley score (r=−0.67, P=0.03) and positively correlated with VAS score (r=0.7, P=0.01). MMP-1 levels were significantly negatively correlated with ASES score (r=−0.57, P<0.001).

Conclusions

The biomarkers in SF were directly associated with shoulder pain and shoulder function in rotator cuff tear. EA, as a safe and effective conservative therapy, obviously decreased the level of inflammatory cytokines in RCT patients, accompanied by a reduction in shoulder pain and improved function.

Mental health and tobacco use are correlated with PROMIS upper extremity and pain interference scores in patients with shoulder pathology

PURPOSE

To determine whether patient demographics have predictive influence on patient-reported outcomes measurement information system (PROMIS) domains of pain interference (PROMIS-PI), depression (PROMIS-D), and upper extremity (PROMIS-UE) for patients with shoulder pathology treated nonoperatively.

METHODS

Patients with partial rotator cuff tears, impingement, scapular dyskinesia, osteoarthritis, muscle strains, biceps tendonitis, instability, and acromioclavicular arthritis were retrospectively identified. Patients who underwent surgery were excluded. Demographic characteristics were documented, and PROMIS scores before and after nonoperative intervention were analyzed for correlations between each domain.

RESULTS

A total of 638 questionnaires (PROMIS-UE, PROMIS-PI, and PROMIS-D) were analyzed. PROMIS-UE had a strong negative correlation with PROMIS-PI (R = - 0.73, P < .001). PROMIS-PI and PROMIS-D demonstrated a positive correlation of moderate strength (R = 0.54, P < .001). Patients who never used tobacco, compared to current or former users, had significantly higher PROMIS-UE scores (34.5 vs. 30.6 and 31.9; P < .001), lower PROMIS-PI (59.7 vs. 63.1 and 60.9; P < .001), and lower PROMIS-D scores (47.3 vs. 52.1 and 49.3; P < .001). Patients with body mass index < 24.8 had significantly higher PROMIS-UE scores than those with > 24.8 (P < .05).

CONCLUSION

There is an inverse relationship between upper extremity physical function and pain and depression, as measured by PROMIS scores. Smoking and increased BMI are significant contributors to worse outcomes in patients with shoulder pathology, even in nonoperative populations. Counseling patients regarding prognosis and functional outcomes is important in managing their expectations in this patient population.

Degenerative rotator cuff tears are associated with a low Omega-3 Index

BACKGROUND

The etiology of degenerative rotator cuff tears is multifactorial but chronic inflammation plays an important role in the pathogenesis. Some polyunsaturated fatty acids (PUFA) can modulate inflammation and marine n-3 (Omega-3) PUFA have anti-inflammatory effects. We hypothesized that the Omega-3 Index is lower in patients with degenerative rotator cuff tears when compared to controls without rotator cuff tendinopathy.

METHODS

From 684 consecutive patients with full thickness rotator cuff tears 655 were excluded because of possible bias. In the remaining 29 patients (22 m, 7 f; 53,9 y) with degenerative full thickness rotator-cuff tears, erythrocyte fatty acids were analyzed using the HS-Omega-3 Index^® methodology. 15 healthy volunteers (10 m, 5 f; 52.5y) served as a control.

RESULTS

The Omega-3 Index (% EPA + DHA) was 5.01% (95% CI: 3.81-4.66) in patients and 6.01% (95% CI: 4.48-5.72) in controls (p = 0.028) CONCLUSIONS: Patients with full thickness degenerative rotator cuff tears had a significantly lower Omega-3 Index than controls without rotator cuff tendinopathy. Whether a lower Omega-3 Index represents an independent risk factor for degenerative rotator cuff tears should be further investigated, e.g. in a longitudinal study.

Synovitis as a concomitant disease in shoulder pathologies

INTRODUCTION

Shoulder pathologies are often accompanied by rotator interval synovitis. This phenomenon is poorly described in the literature so far. The aim of the study was to analyze the occurrence of macroscopically visible synovial reaction in the rotator interval in patients with chronic shoulder pathologies and to perform a histopathological evaluation.

MATERIALS AND METHODS

In this prospective cohort study, 167 consecutive patients undergoing arthroscopic shoulder surgery for chronic shoulder pathology were included (♀ = 45, ♂ = 122; [Formula: see text]54.5 years ± 12.8). Included patients were divided into subgroups according to the encountered chronic shoulder pathology: (1) impingement syndrome with or without bursal sided partial rotator cuff tear (RCT); (2) articular sided partial RCT; (3) full-thickness RCT; (4) RCT that involves at least two tendons; (5) shoulder instability; and (6) cartilage damage. Standardized soft tissue biopsies from the rotator interval were taken. The synovitis score of Krenn/Morawietz was used for histopathological examination.

RESULTS

Extraarticular pathology (group 1) showed significantly decreased synovitis scores compared to all the other groups. Increased size of rotator cuff tears (group 4), as well as cartilage damage (group 6) showed significantly higher synovitis scores than group 3 (p < 0.05). Moreover, the synovitis score was significantly increased in patients with concomitant pathologies of the long head of the biceps (p = 0.001).

CONCLUSIONS

This study suggests that chronic intra- and extraarticular shoulder diseases are very often accompanied by a histopathologically verifiable low-grade synovitis. Intraarticular pathologies seem to induce increased levels of synovitis. Furthermore, the increased size of rotator cuff tears is accompanied by a higher degree of synovitis.

STUDY DESIGN

Cohort study, level of evidence, 2b.

Preoperative Pain Control in Arthroscopic Rotator Cuff Repair: Does It Matter?

Background

The purpose of this study was to clarify the importance of preoperative pain control using corticosteroid injections in patients with persistent rest pain (RP) before arthroscopic rotator cuff repair (ARCR).

Methods

A total of 360 patients (374 shoulders) who underwent primary ARCR and were followed up for at least 2 years were enrolled. After one-to-one propensity score matching, 266 patients (145 men and 128 women, 273 shoulders) were included in the study. Their mean age was 65.2 ± 7.7 years (range, 42 to 88 years) at the time of surgery. The patients were divided into three groups: those who required several intra-articular or subacromial bursa corticosteroid injections preoperatively for refractory RP (group A+), those in whom RP was resolved preoperatively (group A−), and those who had no RP and did not require any injections (group B). The incidence of postoperative RP and preoperative and final follow-up American Shoulder and Elbow Surgeons (ASES) scores were compared among the three groups.

Results

The incidence of postoperative RP was significantly higher in group A+ (35/91 cases, 38.5%) than in group A− (10/91, 11.0%) and group B (7/91, 7.7%, p < 0.001 for both). The preoperative ASES score was significantly lower in group A+ (33.2 ± 14.2) than in group A− (53.9 ± 11.9) and group B (62.3 ± 11.2, p < 0.001 for both), and it was significantly lower in group A− than in group B (p = 0.000). The final follow-up ASES score was significantly lower in group A+ (92.1 ± 8.4) than in group A− (97.6 ± 5.4) and group B (99.0 ± 2.5, p < 0.001 for both). There was no significant difference in the final follow-up ASES score between group A− and group B (p = 0.242).

Conclusions

Patients in whom preoperative RP could be resolved before surgery achieved postoperative outcomes comparable to those in patients who had no RP before surgery, whereas the outcomes in patients with refractory preoperative RP were inferior. The results suggest that preoperative pain control is important in patients undergoing ARCR.

Outcomes After Limited or Extensive Bursectomy During Rotator Cuff Repair: Randomized Controlled Trial

PURPOSE

To evaluate the effects of extensive bursectomy (EB) and limited bursectomy (LB) during arthroscopic rotator cuff repair.

METHODS

In the EB group (n = 39), subacromial bursae were thoroughly removed from anterior to posterior and lateral to medial. In the LB group (n = 39), bursectomy was minimized to allow torn cuff visualization and tendon repair. Visual analog scale pain scores, passive forward flexion, external rotation at the side (ER), and internal rotation at the back were measured at 5 weeks and 3, 6, and 12 months after surgery. At each time point, bursal thickness was measured and repair integrity was assessed by sonography or magnetic resonance imaging.

RESULTS

The analysis included 36 patients in the LB group and 35 in the EB group. Group visual analog scale pain scores were not significantly different at any time (P > .05 for all). Forward flexion and internal rotation at the back showed no intergroup difference during follow-up. However, ER was significantly better in the LB group at 6 months and 1 year postoperatively (31° ± 15° vs 22° ± 16° [P = .020] and 40° ± 19° vs 27° ± 20° [P = .009], respectively). Integrity failures were not significantly different at 5 weeks and at 3, 6, and 12 months (P > .05 for all). Marked bursal thickening (>2 mm) was more frequently observed in the EB group (18 of 32 in the LB group and 27 of 32 in the EB group) at 6 months (P = .014).

CONCLUSIONS

EB during arthroscopic rotator cuff repair appears to have no benefit in terms of reducing pain. More adhesions in the subacromial space after EB may result in slower motion recovery, especially in terms of ER. The extent of bursectomy did not affect tendon integrity. However, marked bursal thickening was more frequently observed in the EB group.

LEVEL OF EVIDENCE

Level I, randomized controlled study.

Microdialysis to Quantify Inflammatory Cytokines in the Glenohumeral Joint: A Brief Methods Report

Microdialysis quantifies in vivo soft-tissue biochemical concentrations via passive diffusion of interstitial molecules through a porous membrane into a dialysate. The purpose of this pilot study was to evaluate a technique to measure inflammatory cytokines associated with rotator cuff tendinopathy by inserting a microdialysis catheter into the posterior glenohumeral joint. The technique was tested in a convenience sample of six pain-free, able-bodied veterans. Complete dialysate samples were collected in two participants. Two participants' sample volumes were smaller than what was required for analysis (30 μl) and thus were diluted. Catheter failures in two participants prevented collection altogether. Three cytokine concentrations were quantified: interleukin-1 receptor antagonist, interleukin 8, and regulated on activation, normal T-cell expressed and secreted. Microdialysis is not recommended for use in the glenohumeral joint, yet quantification of glenohumeral joint cytokines could yield valuable information to better understand pathophysiology of the joint and its surrounding tissues. Another technique, such as joint lavage, may be a more attractive alternative to overcome the limitations of microdialysis in the glenohumeral joint.

A Systematic Summary of Systematic Reviews on the Topic of the Rotator Cuff

BACKGROUND

The number of systematic reviews and meta-analyses published on the rotator cuff (RC) has increased markedly.

PURPOSE

To quantify the number of systematic reviews and meta-analyses published on the RC and to provide a qualitative summary of the literature.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic search for all systematic reviews and meta-analyses pertaining to the RC published between January 2007 and September 2017 was performed with PubMed, MEDLINE, and the Cochrane Database of Systematic Reviews. Narrative reviews and non-English language articles were excluded.

RESULTS

A total of 1078 articles were found, of which 196 met the inclusion criteria. Included articles were summarized and divided into 15 topics: anatomy and function, histology and genetics, diagnosis, epidemiology, athletes, nonoperative versus operative treatment, surgical repair methods, concomitant conditions and surgical procedures, RC tears after total shoulder arthroplasty, biological augmentation, postoperative rehabilitation, outcomes and complications, patient-reported outcome measures, cost-effectiveness of RC repair, and quality of randomized controlled trials.

CONCLUSION

A qualitative summary of the systematic reviews and meta-analyses published on the RC can provide surgeons with a single source of the most current literature.

Enthesis Repair: Challenges and Opportunities for Effective Tendon-to-Bone Healing

On May 22, 2017, the National Institutes of Health (NIH)/National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) hosted a roundtable on "Innovative Treatments for Enthesis Repair." A summary of the roundtable discussion, as well as a list of the extramural participants, can be found at https://www.niams.nih.gov/about/meetings-events/roundtables/roundtable-innovative-treatments-enthesis-repair. This paper reviews the challenges and opportunities for developing effective treatment strategies for enthesis repair that were identified at the roundtable discussion.

Synovial fluid biomarkers: association with chronic rotator cuff tear severity and pain

BACKGROUND

We tested the hypothesis that biomarkers in the synovial fluid of the glenohumeral (shoulder) joint are correlated with visual analog scale (VAS) scores, functional scores, and ultrasound findings of chronic rotator cuff tear (RCT) severity.

METHODS

We measured biomarkers in shoulder joint synovial fluid of 42 patients with partial-thickness (21), nonmassive full-thickness (10), and massive full-thickness (11) RCTs. Pain duration, tear severity, and VAS and functional scores were compared with interleukin (IL) 1β, IL-6, matrix metalloproteinase (MMP) 1, and MMP-13 levels.

RESULTS

Both MMP-1 and MMP-13 levels were significantly highest in the massive full-thickness group. MMP-13 levels were significantly different between groups, but proinflammatory cytokine IL-1β and IL-6 levels were not. However, IL-1β levels were significantly positively correlated with VAS (r = 0.66; P <.01) and functional scores (r = 0.61; P <.01), but IL-6, MMP-1, and MMP-13 levels were not.

CONCLUSIONS

IL-1β levels in shoulder synovial fluid correlated positively with shoulder pain and functional scores in patients with chronic RCTs. Both MMP-1 and MMP-13 levels were altered and increased with cuff tear severity.

Effects of microcurrent and cryotherapy on C-reactive protein levels and muscle tone of patients with rotator cuff reconstruction

[Purpose] The purpose of the present study was to apply early intervention via microcurrent and cryotherapy in patients who underwent rotator cuff reconstruction surgery, and to investigate the effects of such interventions on pain and inflammation levels based on the analysis of C-reactive protein (CRP) levels, and on changes in muscle tone. [Subjects and Methods] The study population consisted of 30 patients who had undergone rotator cuff reconstruction surgery, with 10 patients each assigned to the control, experimental I (E-1), and experimental II (E-II) groups. On the day after surgery, muscle tone, blood CRP level, and pain were measured. For the following two weeks, continues passive motion (CPM), icing, cryotherapy, and microcurrent were applied to the each group. After the respective interventions, CRP levels, pain, and muscle tone near the shoulder area were measured again. [Results] In the post-hoc test of between-group comparison, a statistically significant difference in CRP level was found in the cryotherapy group. A difference in shoulder muscle tone appeared only in the supraspinatus muscle, with post-hoc test results showing that the biggest change occurred in the cryotherapy group. [Conclusion] Cryotherapy may be able to help stabilize inflammation as well as reduce pain and muscle tension when applied in patients following rotator cuff reconstruction.

Combined Administration of ASCs and BMP-12 Promotes an M2 Macrophage Phenotype and Enhances Tendon Healing

BACKGROUND

Outcomes after intrasynovial tendon repair are highly variable. An intense inflammatory cascade followed by a delayed healing response can cause adhesion formation and repair-site failure that severely impair the function of repaired digits. No effective remedies exist to fully address these issues. Cell- and growth factor-based therapies have been shown to modulate inflammation and improve cell proliferation and matrix synthesis and therefore are promising treatment approaches for intrasynovial tendon repair.

QUESTIONS/PURPOSES

(1) Can autologous adipose-derived mesenchymal stromal cells (ASCs) and recombinant bone morphogenetic protein-12 (rBMP-12) be effectively delivered to an intrasynovial flexor tendon repair without adverse effects? (2) Do autologous ASCs modulate the inflammatory response after intrasynovial tendon injury and repair? (3) Does the combined application of autologous ASCs and rBMP-12 modulate the proliferative and remodeling responses after intrasynovial tendon injury and repair?

METHODS

Sixteen 1- to 2-year-old female canines were used in this study. Autologous ASC sheets, with and without rBMP-12, were applied to the surface of sutured flexor tendons. Fourteen days after repair, the effects of treatment were determined using quantitative PCR (six per group) for the expression of genes related to macrophage phenotype or inflammation (IL-4, CD163, VEGF, NOS2, IL-1B, and IFNG), cell proliferation (CCND1), and tendon formation (SCX, TNMD, COL1A1 and COL3A1). Proteomics analysis (four per group) was performed to examine changes in tendon protein abundances. CD146 immunostaining and hematoxylin and eosin staining (four per group) were used to detect tendon stem or progenitor cells and to semiquantitatively evaluate cellularity at the tendon repair; analyses were done blinded to group.

RESULTS

Gross inspection and cell tracing showed that autologous ASCs and rBMP-12 were delivered to the flexor tendon repair site without the deleterious effects of adhesion and repair-site gap formation. Quantitative assessment of gene and protein expression showed effects of treatment: ASC-sheet treatment modulated the postrepair inflammatory response and facilitated healing by increasing regenerative M2 macrophages (M2 marker CD204, twofold of normal, p = 0.030), inflammatory inhibitor (prostaglandin reductase 1 [PTRG1], 1.6-fold of normal, p = 0.026), and proteins involved in tendon formation (periostin [POSTN], 1.9-fold of normal, p = 0.035). Consistently, semiquantitative and qualitative evaluations of repaired tissue showed that ASC-sheet treatment reduced mononuclear cell infiltration (12% less than nontreated tendons, p = 0.021) and introduced CD146+ stem or progenitor cells to the repair site. The combined administration of ASCs and rBMP-12 further stimulated M2 macrophages by increasing IL-4 (116-fold of normal, p = 0.002) and led to the increase of M2 effector matrix metalloproteinase-12 involved in matrix remodeling (twofold of normal, p = 0.016) and reduction of a negative regulator of angiogenesis and cell migration (StAR-related lipid transfer domain protein13 [STARD13]; 84% of normal, p = 0.000), thus facilitating the proliferative stage of tendon repair.

CONCLUSIONS

ASCs and BMP-12 accelerated the progression of healing in the proliferative stage of tendon repair. The effects of ASCs and BMP-12 on tendon functional recovery should be evaluated in future studies.

CLINICAL RELEVANCE

The cell sheet approach is an effective, biocompatible, and surgeon-friendly approach for cell and growth factor delivery during tendon repair. Combined application of ASCs and BMP-12 may accelerate intrasynovial tendon healing while suppressing the adverse inflammatory response.

Association of synovial inflammation and inflammatory mediators with glenohumeral rotator cuff pathology

HYPOTHESIS

We hypothesized that patients with full-thickness rotator cuff tears would have greater synovial inflammation compared with those without rotator cuff tear pathology, with gene expression relating to histologic findings.

METHODS

Synovial sampling was performed in 19 patients with full-thickness rotator cuff tears (RTC group) and in 11 patients without rotator cuff pathology (control group). Cryosections were stained and examined under light microscopy and confocal fluorescent microscopy for anti-cluster CD45 (common leukocyte antigen), anti-CD31 (endothelial), and anti-CD68 (macrophage) cell surface markers. A grading system was used to quantitate synovitis under light microscopy, and digital image analysis was used to quantify the immunofluorescence staining area. Quantitative polymerase chain reaction was performed for validated inflammatory markers. Data were analyzed with analysis of covariance, Mann-Whitney U, and Spearman rank order testing, with significance set at α = .05.

RESULTS

The synovitis score was significantly increased in the RTC group compared with controls. Immunofluorescence demonstrated significantly increased staining for CD31, CD45, and CD68 in the RTC vs control group. CD45+/68- cells were found perivascularly, with CD45+/68+ cells toward the joint lining edge of the synovium. Levels of matrix metalloproteinase-3 (MMP-3) and interleukin-6 were significantly increased in the RTC group, with a positive correlation between the synovitis score and MMP-3 expression.

CONCLUSIONS

Patients with full-thickness rotator cuff tears have greater levels of synovial inflammation, angiogenesis, and MMP-3 upregulation compared with controls. Gene expression of MMP-3 correlates with the degree of synovitis.

Macroscopic and microscopic assessments of the glenohumeral and subacromial synovitis in rotator cuff disease

Background

Whereas synovitis is one of most common findings during arthroscopic surgery in patients with rotator cuff diseases, no study has investigated its characteristics. We propose a macroscopic assessment system for investigating the characteristics of synovitis.

Methods

Fifty-four patients with a full-thickness rotator cuff tear undergoing arthroscopic rotator cuff repair with an average age of 62.5 ± 7.0 years were included. For the macroscopic assessment, 3 parameters, villous hypertrophy, hyperemia, and density, were measured and translated into grades in 3 regions-of-interest (ROI) in the glenohumeral joint and 4 ROIs in the subacromial space. For the microscopic assessments, 4 commonly used microscopic assessment systems were used. The reliability and association between the macroscopic and microscopic assessments were investigated.

Results

The inter- and intra-observer reliability of all of the macroscopic and microscopic assessments were excellent. The severity of synovitis was significantly greater in the glenohumeral joint than that in the subacromial space, 1.54 ± 0.61 versus 0.94 ± 0.56 (p < 0.001). Synovitis varied with respect to location, and was generally more severe near the tear with the macroscopic assessment system. Meanwhile, none of the microscopic assessment systems demonstrated differences between different ROIs in both the glenohumeral joint and the subacromial space.

Conclusions

The macroscopic assessment system for synovitis in rotator cuff disease in this study showed excellent reliability. It critically described characteristics of synovitis that microscopic assessment systems could not. Therefore, this system could be a useful tool for investigating synovitis in rotator cuff disease.

Smoking Predisposes to Rotator Cuff Pathology and Shoulder Dysfunction: A Systematic Review

PURPOSE

To investigate the association of smoking with rotator cuff (RTC) disease and shoulder dysfunction, defined as poor scores on shoulder rating scales.

METHODS

A systematic review was performed using a search strategy based on "shoulder AND [smoke OR smoking OR nicotine OR tobacco]." English-language clinical or basic science studies testing the association of smoking and shoulder dysfunction on shoulder rating scales or disease of the soft tissue of the shoulder were included. Level V evidence studies and articles reporting only on surgery outcomes, subjective symptoms, adhesive capsulitis, or presence of fracture or oncologic mass were excluded.

RESULTS

Thirteen studies were included, comprising a total of 16,172 patients, of whom 6,081 were smokers. All 4 clinical studies addressing the association between smoking and patient-reported shoulder symptoms and dysfunction in terms of poor scores on shoulder rating scales (i.e., Simple Shoulder Test; University of California, Los Angeles shoulder scale; and self-reported surveys) confirmed this correlation with 6,678 patients, of whom 1,723 were smokers. Two of four studies documenting provider-reported RTC disease comprised 8,461 patients, of whom 4,082 were smokers, and found a time- and dose-dependent relation of smoking with RTC tears and a correlation of smoking with impingement syndrome. Smoking was also reported in 4 other articles to be associated with the prevalence of larger RTC tears or tears with pronounced degenerative changes in 1,033 patients, of whom 276 were smokers, and may accelerate RTC degeneration, which could result in tears at a younger age. In addition, 1 basic science study showed that nicotine increased stiffness of the supraspinatus tendon in a rat model.

CONCLUSIONS

Smoking is associated with RTC tears, shoulder dysfunction, and shoulder symptoms. Smoking may also accelerate RTC degeneration and increase the prevalence of larger RTC tears. These correlations suggest that smoking may increase the risk of symptomatic RTC disease, which could consequently increase the need for surgical interventions.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

Tendon extracellular matrix damage, degradation and inflammation in response to in vitro overload exercise

The role of inflammation in tendon injury is uncertain and a topic of current interest. In vitro studies of tendon accelerated overload damage can serve as a valuable source of information on the early stages of tendinopathy. Viable fascicle bundles from bovine flexor tendons were subjected to cyclic uniaxial loading from 1-10% strain. Immuno-staining for inflammatory markers and matrix degradation markers was performed on the samples after mechanical testing. Loaded samples exhibited visible extracellular matrix damage, with disrupted collagen fibers and fiber kinks, and notable damage to the interfascicular matrix. Inflammatory markers COX-2 and IL-6 were only expressed in the cyclically loaded samples. Collagen degradation markers MMP-1 and C1,2C were colocalized in many areas, with staining occurring in the interfascicular matrix or the fascicular tenocytes. These markers were present in control samples, but staining became increasingly intense with loading. Little MMP-3 or MMP-13 was evident in control sections. In loaded samples, some sections showed intense staining of these markers, again localized to interfascicular regions. This study suggests that inflammatory markers may be expressed rapidly after tendon overload exercise. Interestingly, both inflammation and damage-induced matrix remodeling seem to be concentrated in, or in the vicinity of, the highly cellular interfascicular matrix.

Assessment of pain-related behavior and pro-inflammatory cytokine levels in the rat rotator cuff tear model

The cause of pain following rotator cuff tear has not been fully elucidated. The purpose of this study was to evaluate behavior and inflammatory cytokines in a rat unstabilized rotator cuff defect (UCD) model. Forty-five Sprague-Dawley rats were divided into three groups: sham; UCD; and stabilized rotator cuff defect (SCD). Gait analysis was examined using CatWalk. Tumor necrosis factor (TNF)-α, interleukin(IL)-1β, and IL-6 were measured within the subacromial bursa and the glenohumeral joint synovium at 21 and 56 days after surgery using an enzyme-linked immunosorbent assay (ELISA). Stride length, print area and contact intensity in the UCD group was significantly lower than in the sham group after surgery. Stride length, print area and contact intensity in the SCD group was significantly higher than in the UCD group. In contrast, TNF-α, IL-1β, and IL-6 in the UCD group was significantly higher than in the sham group at days 21 and 56. However, TNF-α, IL-1β, and IL-6 in the SCD group was significantly lower than in the UCD group at days 21 and 56. The present results suggest that SCD is effective not only in improving shoulder function but also in reducing inflammatory cytokines, which may serve as one source of pain due to rotator cuff tear.

Role of serum fibrinogen levels in patients with rotator cuff tears

Although rotator cuff (RC) tendinopathy is a frequent pathology of the shoulder, the real understanding of its aetiopathogenesis is still unclear. Several studies showed that RC tendinopathy is more frequent in patients with hyperglycemia, diabetes, obesity, or metabolic syndrome. This paper aims to evaluate the serum concentration of fibrinogen in patients with RC tears. Metabolic disorders have been related to high concentration of serum fibrinogen and the activity of fibrinogen has been proven to be crucial in the development of microvascular damage. Thus, it may produce progression of RC degeneration by reducing the vascular supply of tendons. We report the results of a cross-sectional frequency-matched case-control study comparing the serum concentration of fibrinogen of patients with RC tears with that of a control group of patients without history of RC tears who underwent arthroscopic meniscectomy. We choose to enrol in the control group patients with pathology of the lower limb with a likely mechanic, not metabolic, cause, different from tendon pathology. We found no statistically significant differences in serum concentration of fibrinogen when comparing patients with RC tears and patients who underwent arthroscopic meniscectomy (P = 0.5). Further studies are necessary to clarify the role of fibrinogen in RC disease.

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.

A systematic review of the histological and molecular changes in rotator cuff disease

INTRODUCTION

The pathogenesis of rotator cuff disease (RCD) is complex and not fully understood. This systematic review set out to summarise the histological and molecular changes that occur throughout the spectrum of RCD.

METHODS

We conducted a systematic review of the scientific literature with specific inclusion and exclusion criteria.

RESULTS

A total of 101 studies met the inclusion criteria: 92 studies used human subjects exclusively, seven used animal overuse models, and the remaining two studies involved both humans and an animal overuse model. A total of 58 studies analysed supraspinatus tendon exclusively, 16 analysed subacromial bursal tissue exclusively, while the other studies analysed other tissue or varying combinations of tissue types including joint fluid and muscle. The molecular biomarkers that were altered in RCD included matrix substances, growth factors, enzymes and other proteins including certain neuropeptides.

CONCLUSIONS

The pathogenesis of RCD is being slowly unravelled as a result of the significant recent advances in molecular medicine. Future research aimed at further unlocking these key molecular processes will be pivotal in developing new surgical interventions both in terms of the diagnosis and treatment of RCD.

Curcumin modulates nuclear factor kappaB (NF-kappaB)-mediated inflammation in human tenocytes in vitro: role of the phosphatidylinositol 3-kinase/Akt pathway

Inflammatory processes play essential roles in the pathogenesis of tendinitis and tendinopathy. These events are accompanied by catabolic processes initiated by pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Pharmacological treatments for tendinitis are restricted to the use of non-steroidal anti-inflammatory drugs. Recent studies in various cell models have demonstrated that curcumin targets the NF-κB signaling pathway. However, its potential for the treatment of tendinitis has not been explored. Herein, we used an in vitro model of human tenocytes to study the mechanism of curcumin action on IL-1β-mediated inflammatory signaling. Curcumin at concentrations of 5-20 μm inhibited IL-1β-induced inflammation and apoptosis in cultures of human tenocytes. The anti-inflammatory effects of curcumin included down-regulation of gene products that mediate matrix degradation (matrix metalloproteinase-1, -9, and -13), prostanoid production (cyclooxygenase-2), apoptosis (Bax and activated caspase-3), and stimulation of cell survival (Bcl-2), all known to be regulated by NF-κB. Furthermore, curcumin suppressed IL-1β-induced NF-κB activation via inhibition of phosphorylation and degradation of inhibitor of κBα, inhibition of inhibitor of κB-kinase activity, and inhibition of nuclear translocation of NF-κB. Furthermore, the effects of IL-1β were abrogated by wortmannin, suggesting a role for the phosphatidylinositol 3-kinase (PI-3K) pathway in IL-1β signaling. Curcumin suppressed IL-1β-induced PI-3K p85/Akt activation and its association with IKK. These results demonstrate, for the first time, a potential role for curcumin in treating tendon inflammation through modulation of NF-κB signaling, which involves PI-3K/Akt and the tendon-specific transcription factor scleraxis in tenocytes.

Lifestyle and metabolic factors in relation to shoulder pain and rotator cuff tendinitis: a population-based study

Background

Shoulder pain is a common health problem. The purpose of this study was to assess the associations of lifestyle factors, metabolic factors and carotid intima-media thickness with shoulder pain and chronic (> 3 months) rotator cuff tendinitis.

Methods

In this cross-sectional study, the target population consisted of subjects aged 30 years or older participating in a national Finnish Health Survey during 2000-2001. Of the 7,977 eligible subjects, 6,237 (78.2%) participated in a structured interview and clinical examination. Chronic rotator cuff tendinitis was diagnosed clinically. Weight-related factors, C-reactive protein and carotid intima-media thickness were measured.

Results

The prevalence of shoulder joint pain during the preceding 30 days was 16% and that of chronic rotator cuff tendinitis 2.8%. Smoking, waist circumference and waist-to-hip ratio were related to an increased prevalence of shoulder pain in both genders. Metabolic syndrome, type 2 diabetes mellitus and carotid intima-media thickness were associated with shoulder pain in men, whereas high level of C-reactive protein was associated with shoulder pain in women. Increased waist circumference and type 1 diabetes mellitus were associated with chronic rotator cuff tendinitis in men.

Conclusions

Our findings showed associations of abdominal obesity, some other metabolic factors and carotid intima-media thickness with shoulder pain. Disturbed glucose metabolism and atherosclerosis may be underlying mechanisms, although not fully supported by the findings of this study. Prospective studies are needed to further investigate the role of lifestyle and metabolic factors in shoulder disorders.

The prevalence of neovascularity in patients clinically diagnosed with rotator cuff tendinopathy

Background

Shoulder dysfunction is common and pathology of the rotator cuff tendons and subacromial bursa are considered to be a major cause of pain and morbidity. Although many hypotheses exist there is no definitive understanding as to the origin of the pain arising from these structures. Research investigations from other tendons have placed intra-tendinous neovascularity as a potential mechanism of pain production. The prevalence of neovascularity in patients with a clinical diagnosis of rotator cuff tendinopathy is unknown. As such the primary aim of this pilot study was to investigate if neovascularity could be identified and to determine the prevalence of neovascularity in the rotator cuff tendons and subacromial bursa in subjects with unilateral shoulder pain clinically assessed to be rotator cuff tendinopathy. The secondary aims were to investigate the association between the presence of neovascularity and pain, duration of symptoms, and, neovascularity and shoulder function.

Methods

Patients with a clinical diagnosis of unilateral rotator cuff tendinopathy referred for a routine diagnostic ultrasound (US) scan in a major London teaching hospital formed the study population. At referral patients were provided with an information document. On the day of the scan (on average, at least one week later) the patients agreeing to participate were taken through the consent process and underwent an additional clinical examination prior to undergoing a bilateral grey scale and colour Doppler US examination (symptomatic and asymptomatic shoulder) using a Philips HDI 5000 Sono CT US machine. The ultrasound scans were performed by one of two radiologists who recorded their findings and the final assessment was made by a third radiologist blinded both to the clinical examination and the ultrasound examination. The findings of the radiologists who performed the scans and the blinded radiologist were compared and any disagreements were resolved by consensus.

Results

Twenty-six patients agreed to participate and formed the study population. Of these, 6 subjects were not included in the final assessment following the pre-scan clinical investigation. This is because one subject had complete cessation of symptoms between the time of the referral and entry into the trial. Another five had developed bilateral shoulder pain during the same period. The mean age of the 20 subjects forming the study population was 50.2 (range 32-69) years (SD = 10.9) and the mean duration of symptoms was 22.6 (range .75 to 132) months (SD = 40.1). Of the 20 subjects included in the formal analysis, 13 subjects (65%) demonstrated neovascularity in the symptomatic shoulder and 5 subjects (25%) demonstrated neovascularity in the asymptomatic shoulder. The subject withdrawn due to complete cessation of symptoms was not found to have neovascularity in either shoulder and of the 5 withdrawn due to bilateral symptoms; two subjects were found to have signs of bilateral neovascularity, one subject demonstrated neovascularity in one shoulder and two subjects in neither shoulder.

Conclusions

This study demonstrated that neovascularity does occur in subjects with a clinical diagnosis of rotator cuff tendinopathy and to a lesser extent in asymptomatic shoulders. In addition, the findings of this investigation did not identify an association between the presence of neovascularity; and pain, duration of symptoms or shoulder function. Future research is required to determine the relevance of these findings.

Rotator cuff tears: pathology and repair

By virtue of its anatomy and function, the rotator cuff is vulnerable to considerable morbidity, often necessitating surgical intervention. The factors contributing to cuff disease can be divided into those extrinsic to the rotator cuff (most notably impingement) and those intrinsic to the cuff (age-related degeneration, hypovascularity and inflammation amongst others). In an era of emerging biologic interventions, our interventions are increasingly being modulated by our understanding of these core processes, many of which remain uncertain today. When we do intervene surgically, the techniques we employ are particularly challenging in the context of the tremendous pace of advancement. Several recent studies have shown that arthroscopic repair gives similar functional results to that of mini-open and open procedures, with all the benefits of minimally invasive surgery. However, the 'best' repair construct remains unknown, with wide variations in surgeon preference. Here we present a literature review encompassing recent developments in our understanding of basic science in rotator cuff disease as well as an up-to-date evidence-based comparison of different techniques available to the surgeon for cuff repair.

Shoulder ultrasound abnormalities, physical examination findings, and pain in manual wheelchair users with spinal cord injury

OBJECTIVES

To investigate the presence of ultrasound (US) abnormalities in manual wheelchair users with spinal cord injury (SCI) using a quantitative Ultrasound Shoulder Pathology Rating Scale (USPRS). To investigate physical examination (PE) findings using a quantitative Physical Examination of the Shoulder Scale (PESS), and to obtain data about pain and other subject characteristics such as age, years with SCI, and weight.

DESIGN

Case series.

SETTING

National Veterans' Wheelchair Games 2005 and 2006.

PARTICIPANTS

Volunteer sample of manual wheelchair users with SCI participating in the National Veterans' Wheelchair Games.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Presence of relationships between US findings, PE findings, pain, and subject characteristics.

RESULTS

The USPRS correlated with age, duration of SCI, and weight (all P<.01), and showed a positive trend with the total Wheelchair User's Shoulder Pain Index (WUSPI) score (r=.258, P=.073). Several US findings related to presence of PE findings for specific structures. The PESS score correlated with the WUSPI (r=.679, P<.001) and duration of SCI (P<.05). The presence of untreated shoulder pain that curtailed activity was noted in 24.5% of subjects, and this was related to increased WUSPI scores (P=.002).

CONCLUSIONS

PE and US abnormalities are common in manual wheelchair users with SCI. The USPRS and PESS demonstrated evidence for external validity and hold promise as research tools. Untreated shoulder pain is common in manual wheelchair users with SCI, and further investigation of this pain is indicated.

The validity of the lag signs in diagnosing full-thickness tears of the rotator cuff: a preliminary investigation

OBJECTIVE

To investigate whether the lag signs were valid tools in diagnosing full-thickness tears of the rotator cuff.

DESIGN

A same-subject, correlation, double-blinded design was used. The results of the external rotation lag sign, drop sign, and internal rotation lag sign were compared with the criterion standard of diagnostic ultrasound to establish their accuracy.

SETTING

A regional orthopedic hospital.

PARTICIPANTS

Consecutive subjects (N=37), 21 women and 16 men, with shoulder pain referred to a consultant orthopedic surgeon specializing in shoulder conditions were recruited for this investigation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative likelihood ratios of the lag signs when using ultrasound as the reference test.

RESULTS

The specificities of the drop sign and internal rotation lag sign were 77% and 84%, respectively, which, together with low positive likelihood ratios 3.2 (95% confidence interval [CI], 1.5-6.7) and 6.2 (95% CI, 1.9-12.0), indicate that a positive result was poor at recognizing the presence of full-thickness tears. The drop sign had a sensitivity of 73% with a negative likelihood ratio of .34 (95% CI, 0.2-0.8), suggesting that a negative test was fair at ruling out the presence of full-thickness tears. The sensitivity of the internal rotation lag sign (100%) supported by the negative likelihood ratio of 0 (95% CI, 0.0-2.5) suggests that a negative test will effectively rule out the presence of full-thickness tears of the subscapularis. A positive external rotation lag sign is the clinical test most likely to indicate that full-thickness tears of the supraspinatus and infraspinatus are present (specificity, 94%). However, the external rotation lag sign did demonstrate a low sensitivity score of 46% and negative likelihood ratio of .57 (95% CI, 0.4-0.9), which means that a negative test will not rule out the presence of full-thickness tears.

CONCLUSIONS

The findings of this investigation suggest that a clinical diagnosis of a full-thickness tear of the rotator cuff cannot be conclusively reached using one or more of the lag signs.

Rotator cuff degeneration: etiology and pathogenesis

By virtue of its anatomy and function, the rotator cuff is vulnerable to considerable morbidity, often necessitating surgical intervention. How we intervene is governed by our understanding of the pathological mechanisms in cuff disease. These factors can be divided into those extrinsic to the rotator cuff (impingement, demographic factors) and those intrinsic to the cuff (age-related degeneration, hypovascularity, inflammation, and oxidative stress, among others). In an era where biologic interventions are increasingly being investigated, our understanding of these mechanisms is likely to become more important in designing effective new interventions. Here we present a literature review summarizing our current understanding of the pathophysiological mechanisms underlying rotator cuff degeneration.

EP4 receptor regulates collagen type-I, MMP-1, and MMP-3 gene expression in human tendon fibroblasts in response to IL-1 beta treatment

Tendinopathy is accompanied by inflammation, tendon matrix degradation, or both. Inflammatory cytokine IL-1beta, which is a potent inflammatory mediator, is likely present within the tendon. The purpose of this study was to determine the biological impact of IL-1beta on tendon fibroblasts by assessing the expression of cPLA(2), COX-2, PGE(2) and its receptors (EPs), collagen type-I, and MMPs. We also studied the role of the p38 MAPK pathway in IL-1beta-induced catabolic effects. We found that IL-1beta increased the expression levels of cPLA(2) and COX-2, and also increased the secretion of PGE(2). Induction of MMPs, such as MMP-1 and MMP-3 at the mRNA level, was also observed after stimulation with IL-1beta. Furthermore, the presence of IL-1beta significantly decreased the level of collagen type-I mRNA in tendon fibroblasts. These effects were found to be mediated by selective upregulation of EP(4) receptor, which is a member of G-protein-coupled receptor that transduces the PGE(2) signal. Blocking EP(4) receptor by a specific chemical inhibitor abolished IL-1beta-induced catabolic effects. These results suggest that IL-1beta-induced catabolic action on tendon fibroblasts occurs via the upregulation of two key inflammatory mediators, cPLA(2) and COX-2, which are responsible for the synthesis of PGE(2). IL-1beta further stimulates the expression of EP(4) receptor, suggesting positive feedback regulation which may lead to accelerated catabolic processes in tendon fibroblasts. Studies using pathway-specific chemical inhibitors suggest that the p38 MAPK pathway is the key signaling cascade transducing IL-1beta-mediated catabolic effects. Collectively, our findings suggest that the EP(4) receptor mediates the IL-1beta-induced catabolic metabolism via the p38 MAPK pathway in human tendon fibroblasts and may play a major role in the tendon's degenerative changes often seen in the later stages of tendinopathy.

Expression of interleukin-1beta, cyclooxygenase-2, and prostaglandin E2 in a rotator cuff tear in rabbits

We investigated the specific factors related to shoulder pain due to a rotator cuff tear using a model in rabbits. A rotator cuff tear was surgically created, and the expression of interleukin-1beta (IL-1beta), prostaglandin E2 (PGE2), and cyclooxygenase-2 (COX-2) was analyzed. In the supernatant of the tissue culture of the torn tendon, IL-1beta production was detected. The amount of IL-1beta was highest 1 day after injury, and then decreased gradually to 21 days. PGE2, the mediator of pain and the product of COX-2, was also detected in the supernatant of the tissue culture. The production of PGE2 significantly increased to 7 days after injury, and then decreased to 21 days. RT-PCR analysis confirmed the mRNA expression of IL-1beta and COX-2 in the torn tendon. Immunohistochemical study demonstrated that cells in the tendon stump were immunopositive for IL-1beta and COX-2. Furthermore, in the affected joint, articular chondrocytes in the remote area from the tear expressed COX-2 strongly. When the rotator cuff is torn, IL-1beta is produced in the torn tendon, and stimulates the expression of COX-2 in not only the torn tendon but also in articular chondrocytes. The COX-2 then produces PGE2, which would mediate shoulder pain.

Partial-thickness rotator cuff tears

Partial-thickness rotator cuff tears are not a single entity; rather, they represent a spectrum of disease states. Although often asymptomatic, they can be significantly disabling. Overhead throwing athletes with partial-thickness rotator cuff tears differ with respect to etiology, goals, and treatment from older, nonathlete patients with degenerative tears. Pathogenesis of degenerative partial-thickness tears is multifactorial, with evidence of intrinsic and extrinsic factors playing key roles. Diagnosis of partial-thickness rotator cuff tears should be based on the patient's symptoms together with magnetic resonance imaging studies. Conservative treatment is successful in most patients. Surgery generally is considered for patients with symptoms of sufficient duration and intensity. The role of acromioplasty has not been clearly delineated, but it should be considered when there is evidence of extrinsic causation for the partial-thickness rotator cuff tear.

The molecular pathophysiology of subacromial bursitis in rotator cuff disease

Little information exists on the molecular and biochemical pathophysiology of subacromial bursitis and rotator cuff disease. We investigated the pattern of expression of cytokines (interleukin [IL]-1beta, IL-1, IL-6, tumor necrosis factor [TNF] alpha, small inducible cytokines), metalloproteases, and cyclooxygenases in the subacromial bursa in patients with rotator cuff disease. Subacromial bursa specimens were prepared for molecular and biochemical analysis in patients undergoing shoulder surgery following an institutional review board-approved protocol. Specimens were analyzed for the presence of cytokines, metalloproteases, and cyclooxygenases by use of microarray for gene expression and immunohistocytochemistry. Microarray analysis for gene expression and immunohistochemistry demonstrated that the expression of several cytokine genes (TNF, IL-1alpha, IL-1beta, and IL-6) was increased in patients with subacromial bursitis compared with control specimens. Furthermore, the expression of metalloproteases (MMP-1 and MMP-9) and cyclooxygenases (COX-1 and COX-2) in the bursitis group was found to be increased as compared with controls. Although further investigation is required, these studies suggest that inflammation of the subacromial bursa does occur in patients with rotator cuff disease. These findings support the role of anti-inflammatory agents in the treatment of subacromial impingement and emphasize the importance of subacromial bursectomy to reduce inflammation in rotator cuff disease.