Effects of corticosteroids and hyaluronic acid on torn rotator cuff tendons in vitro and in rats

Influence of Frequent Corticosteroid Local Injections on the Expression of Genes and Proteins Related to Fatty Infiltration, Muscle Atrophy, Inflammation, and Fibrosis in Patients With Chronic Rotator Cuff Tears: A Pilot Study

Background

The effect of local corticosteroid (CS) injections on rotator cuff muscles remains poorly defined, despite the significance of muscle quality as a crucial prognostic factor for patients with rotator cuff tears (RCTs).

Purpose

To compare alterations in gene and protein expression patterns in the rotator cuff muscles of patients with RCTs who received frequent joint CS injections with alterations in those without a history of CS injections.

Study Design

Controlled laboratory study.

Methods

A total of 24 rotator cuff muscle samples with medium-sized tears from 12 patients with a frequent joint CS injection history (steroid group; 7 men and 5 women who had received ≥5 injections with at least 1 within the previous 3 months; mean age, 63.0 ± 7.2 years) and 12 age- and sex-matched control patients without a history of CS injections (no-steroid group) were acquired. Alterations in the expression of genes and proteins associated with adipogenesis, myogenesis, inflammation, and muscle fibrosis were compared between the groups using quantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. Statistical analysis included comparison of group means using the Mann-Whitney U test, chi-square test, or Fisher exact test and logistic regression for multivariate analysis.

Results

In the steroid group, the mRNA expression levels of adipogenic CCAAT/enhancer-binding protein alpha (C/EBPα; P = .008) and muscle atrophy-related genes (atrogin; P = .019) were significantly higher, and those of myogenic differentiation 1 (MyoD; P = .035), inflammatory interleukin 6 (IL-6; P = .035), and high mobility group box 1 (P = .003) were significantly lower compared with the no-steroid group. In addition, MyoD (P = .041) and IL-6 (P = .026) expression were decreased in the steroid versus no-steroid group. Immunohistochemistry revealed increased expression of C/EBPα and atrogin and decreased expression of MyoD and IL-6 in the steroid versus no-steroid group.

Conclusion

Patients with RCTs and a history of frequent CS injections exhibited an upregulation of adipogenic and muscle atrophy-related genes and proteins within the rotator cuff muscles and a downregulation in the expression of myogenic and inflammatory genes and proteins in the same muscles.

Clinical Relevance

These altered gene and protein expressions by frequent local CS injections may cause poor outcomes in patients with RCTs.

Clinical effects of sodium hyaluronate combined with platelet-rich plasma injection on rotator cuff injury in arthroscopic repair

Objective

Rotator cuff injury is one prevalent shoulder condition that often leads to pain and dysfunction. The study explored the clinical effects of sodium hyaluronate combined with platelet-rich plasma (PRP) injection on rotator cuff injury in arthroscopic repair.

Methods

A total of 92 cases with rotator cuff injury were randomly divided into the control group (n = 46, treated with shoulder arthroscopy repair combined with subacromial space injection of sodium hyaluronate) and the experimental group (n = 46, treated with subacromial space injection of autologous PRP on the basis of the treatment in the control group). Visual analogue scale (VAS), Constant-Murley scale (CMS), University of California, Los Angeles (UCLA), American Shoulder and Elbow Society (ASES), and quality of life (QOL) scores, as well as complications were compared in the two groups before surgery and at 3 and 6 months after surgery. Shoulder range of motion (ROM) was measured before and after surgery.

Results

VAS scores of patients in the two groups at 3 and 6 months after surgery were lower than those before surgery, and the VAS scores of patients in the experimental group at 3 and 6 months after surgery were much lower than those in the control group (all P < 0.05). The scores of CMS, UCLA, ASES, and QOL, and shoulder ROM in both groups at 3 and 6 months after surgery were higher than those before surgery, and these shoulder joint function scores, QOL and shoulder ROM in the experimental group at 3 and 6 months after surgery were higher than those in the control group (all P < 0.05). No statistically significant difference presented in the incidence of complications between the two groups (P > 0.05).

Conclusion

Arthroscopic rotator cuff repair and sodium hyaluronate combined with PRP injection can effectively reduce pain symptoms, improve shoulder joint function and shoulder ROM, and improve QOL in patients with rotator cuff injury.

[The use of sodium hyaluronate to treat upper limb disease: A review]

The most common diseases of the upper limb are osteoarthritis (OA) of the joints of the hands, lateral epiconlitis, tendinitis of the shoulder muscles, adhesive capsulitis. OA of the shoulder and acromioclavicular joints is less common. The development of acute and subacute pain in the elbow and shoulder joints in the vast majority of cases is determined by the pathology of soft tissues: muscles, ligamentous apparatus and related synovial bags, making it difficult to diagnose. A clinical and radiological heterogeneity of OA of the joints of the hands is a very complex pathology for the study, and also to create a unified algorithms for therapy. Therapy nonsteroidal anti-inflammatory drugs are effective in the short term, but it has several side effects. Despite a variety of attempts at therapy with successful and unsuccessful outcome, the attention of researchers for several decades converted to the injection therapy with hyaluronic acid. The article presents the data of studies demonstrating the anti-inflammatory effect of hyaluronic acid in the treatment of OA, as well as the results of clinical trials and data system of meta-analysis demonstrating the effectiveness of intra-articular and extra-articular therapy tendinopathy of the upper limb. Most of the cited studies demonstrated the efficacy and good tolerance of 1% sodium hyaluronate. In the domestic market it is presented in the drug Flexotron Forte. The authors provide the results of the study results, demonstrating the efficacy and safety of using Flexotron Forte to clinical practice.

Effect of suprascapular nerve injury on muscle and regenerated enthesis in a rat rotator cuff tear model

BACKGROUND

Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model.

METHODS

Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (-) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively.

RESULTS

SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (-) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (-) group. The bone-tendon junction enthesis was firm in the SN injury (-) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon-bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups.

CONCLUSIONS

In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs. Level of evidence: Basic research, controlled laboratory study.

Intra-Articular Hyaluronic Acid in Osteoarthritis and Tendinopathies: Molecular and Clinical Approaches

Musculoskeletal diseases continue to rise on a global scale, causing significant socioeconomic impact and decreased quality of life. The most common disorders affecting musculoskeletal structures are osteoarthritis and tendinopathies, complicated orthopedic conditions responsible for major pain and debilitation. Intra-articular hyaluronic acid (HA) has been a safe, effective, and minimally invasive therapeutic tool for treating these diseases. Several studies from bedside to clinical practice reveal the multiple benefits of HA such as lubrication, anti-inflammation, and stimulation of cellular activity associated with proliferation, differentiation, migration, and secretion of additional molecules. Collectively, these effects have demonstrated positive outcomes that assist in the regeneration of chondral and tendinous tissues which are otherwise destroyed by the predominant catabolic and inflammatory conditions seen in tissue injury. The literature describes the physicochemical, mechanical, and biological properties of HA, their commercial product types, and clinical applications individually, while their interfaces are seldom reported. Our review addresses the frontiers of basic sciences, products, and clinical approaches. It provides physicians with a better understanding of the boundaries between the processes that lead to diseases, the molecular mechanisms that contribute to tissue repair, and the benefits of the HA types for a conscientious choice. In addition, it points out the current needs for the treatments.

Treatment With Glycogen Synthase Kinase 3β Inhibitor Decreases Apoptotic and Autophagic Reactions in Rat Rotator Cuff Tears

Background:

Apoptosis and autophagy are known to be correlated with the extent of damage in torn rotator cuffs, and there is no biological evidence for self-recovery or healing of the rotator cuff tear.

Purpose:

To establish in a rat model of partial- and full-thickness rotator cuff tears how a glycogen synthase kinase 3β (GSK-3β) inhibitor affects the expression of apoptotic and autophagic markers.

Study Design:

Controlled laboratory study.

Methods:

Twelve-week-old Sprague Dawley rats were divided into 3 groups (n = 16 per group). Group 1 acted as the control, with no treatment; group 2 received partial-thickness (right side) and full-thickness (left side) rotator cuff tears only; and group 3 received the same rotator cuff injuries, with GSK-3β inhibitor injected afterward. The tendons from each group were harvested 42 days after surgery. Evaluation of gene expression, immunohistochemistry, and TUNEL staining (terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling) were performed for the following markers: caspases 3, 8, and 9 as well as Bcl-2 (B-cell lymphoma 2); BAX (Bcl-2-associated X protein); beclin 1; p53; and GSK-3β; which represented apoptotic and autophagic reactions. Statistical analysis was performed using 1-way analysis of variance.

Results:

In the group 2 rats with partial- and full-thickness tears, there were significant increases in the mRNA levels (fold changes) of all 8 markers as compared with group 1 (control). All these increased markers showed significant downregulation by the GSK-3β inhibitor in partial-thickness tears. However, the response to the GSK-3β inhibitor in full-thickness tears was not as prominent as in partial-thickness tears. The number of TUNEL-positive cells in group 2 (partial, 35.08% ± 1.625% [mean ± SE]; full, 46.92% ± 1.319%) was significantly higher than in group 1 (18.02% ± 1.036%; P < .01) and group 3 (partial, 28.04% ± 2.607% [P < .01]; full, 38.97% ± 2.772% [P < .01]), and immunohistochemistry revealed increased expression of all the markers in group 2 as compared with control.

Conclusion:

The apoptotic and autophagic activity induced in a rat model of an acute rotator cuff tear was downregulated after treatment with a GSK-3β inhibitor, particularly with partial-thickness rotator cuff tears.

Clinical Relevance:

A GSK-3β inhibitor may be able to modulate deterioration in a torn rotator cuff.

The Impact of Hyaluronic Acid on Tendon Physiology and Its Clinical Application in Tendinopathies

The physical-chemical, structural, hydrodynamic, and biological properties of hyaluronic acid within tendons are still poorly investigated. Medical history and clinical applications of hyaluronic acid for tendinopathies are still debated. In general, the properties of hyaluronic acid depend on several factors including molecular weight. Several preclinical and clinical experiences show a good efficacy and safety profile of hyaluronic acid, despite the absence of consensus in the literature regarding the classification according to molecular weight. In in vitro and preclinical studies, hyaluronic acid has shown physical-chemical properties, such as biocompatibility, mucoadhesivity, hygroscopicity, and viscoelasticity, useful to contribute to tendon healing. Additionally, in clinical studies, hyaluronic acid has been used with promising results in different tendinopathies. In this narrative review, findings encourage the clinical application of HA in tendinopathies such as rotator cuff, epicondylitis, Achilles, and patellar tendinopathy.

The Role of Hyaluronic Acid in Sport-Related Tendinopathies: A Narrative Review

Tendinopathy is a complex clinical condition with a rising incidence and prevalence, particularly during sports practice. For the return to play in affected patients, adequate functional and structural recovery of the tendon is the ultimate goal, avoiding the high risk of recurrence. In this perspective, local therapies alongside exercise are showing promising results. Despite evidence suggesting hyaluronic acid (HA) injections as effective in the treatment of tendinopathy, current recommendations about the management of this condition do not include this intervention. HA seems to be an effective therapeutic option for the management of sport-related tendinopathies, but further studies with a larger sample size are needed to confirm available findings. In this narrative review, we analyzed available literature about the rationale of the use of HA in the management of tendon injury and, particularly, in sport-related tendinopathies.

Low Molecular-weight Hyaluronic Acid Versus Physiotherapy for the Treatment of Supraspinatus Tendinopathy: A Randomized Comparative Clinical Trial

INTRODUCTION

The tendons of the rotator cuff are major sources of shoulder pain. This study aimed to compare the effects of low molecular-weight hyaluronic acid with physiotherapy (PT) in patients with supraspinatus tendinopathy (ST).

METHODS

We carried out a parallel two-group randomized comparative clinical trial in an outpatient clinic of physical medicine and rehabilitation at a teaching hospital. In total, 51 patients (31 women) aged 20 to 55 years with ST were randomly allocated to subacromial hyaluronate injection (n = 28) and PT (n = 23) groups. For the hyaluronate group, we administered a single injection of 2 mL (20 mg) hyaluronate 1% (500 to 700 kDa). For PT, we prescribed three sessions of treatment per week for 12 weeks, totaling 36 sessions including rotator cuff activation exercises. The primary outcome was shoulder pain in the visual analog scale. The secondary outcomes included the range of movement and the disability score of the shoulder, and a World Health Organization questionnaire on quality of life. We did the measurements at the baseline and at one, four, and 12 weeks after intervention.

RESULTS

The results showed that both interventions were beneficial in the management of ST. However, hyaluronate was more effective in reducing shoulder pain at rest and during activities (both P < 0.001, effect size = 0.52 and 0.68, respectively). The two interventions similarly decreased patients' disability (P = 0.196). Hyaluronate improved shoulder motion and the quality of life better than PT.

CONCLUSION

In the treatment of ST, low molecular-weight hyaluronate is more effective than PT, at least for three months. Particularly, hyaluronate is more successful in alleviating pain.

Effect of co-administration of atelocollagen and hyaluronic acid on rotator cuff healing

Background

This study aimed to evaluate the co-administration effect of atelocollagen combined with hyaluronic acid (HA) injections for treatment of full-thickness rotator cuff tear (RCT).

Methods

Eighty patients who underwent arthroscopic rotator cuff repair for full-thickness RCT from March 2018 to November 2019 were enrolled. The patients were randomly allocated to the following groups: combined atelocollagen and HA injection (group I, n=28), only HA injection (group II, n=26), and no injection (group III, n=26). Clinical outcomes were assessed at 3, 6, and 12 months after surgery using the American Shoulder and Elbow Surgeons score, visual analog scale pain score , functional scores (pain visual analog scale, function visual analog score), and range of motion. Magnetic resonance imaging was performed 12 months after surgery to evaluate rotator cuff integrity.

Results

Preoperative demographic data and postoperative clinical outcomes did not differ significantly among the three groups (p>0.05). However, in group I, the number of steroid injections after surgery was significantly lower than that in the other groups (p=0.011). The retear rate on follow-up magnetic resonance imaging was significantly higher in group II (9.5%, n=2) and group III (13.6%, n=3) than in group I (0%) (p=0.021).

Conclusions

Co-administration of atelocollagen and HA improves healing of the rotator cuff and increases the integrity of the rotator cuff repair site. This study provides encouraging evidence for use of combined atelocollagen-HA injections to treat patients with full-thickness RCT.

Efficacy Comparison of Hyaluronic Acid and Corticosteroid Injection in Treatment of Trigger Digits: A Randomized Controlled Trial

Background: Although the current nonsurgical treatment for trigger digits is corticosteroid (CS) injection, it often comes with adverse effects that may cause some limitations. Currently, Hyaluronic acid (HA) has been successfully used in tendinopathy and may be used in stenosing tenosynovitis. The aim of this study is to compare the efficacy of ultrasound-guided injection between the HA and CS in trigger digits treatment. Methods: Double-blind randomized controlled trial was conducted. Fifty patients with 66 trigger digits were randomly assigned into an intervention group (1 ml of low-molecular weight HA) and a control group (1 ml of 10mg/ml triamcinolone acetate). The ultrasound-guided injection and local anesthesia (0.5 ml of 1% lidocaine without adrenaline) were used. The Quinnell grading, Visual Analog Scale (VAS) score of pain, Disabilities of the Arm, Shoulder and Hand (DASH) score and complications were collected at 1-, 3-and 6-month follow-up. Results: The mean age of HA group (33 digits) and CS group (33 digits) were 58.3 years and 54.7 years respectively. Nine patients were loss of follow-up (7 in HA group and 2 in CS group). The Quinnell grades have shown an improvement in both group. The CS group had a significant better improvement at 1-month (p-value < 0.001) and there was no significant difference at 3-and 6-month follow-up between the two groups. The median of VAS and DASH score were significantly improved by time in both groups (p-value < 0.01). The CS group showed a better significant improvement in early period of follow-up (p-value < 0.05). However, there was no significant difference between the two groups in the last follow-up. Conclusions: HA and CS injection has a comparable therapeutic effect in treatment of trigger digits. However, CS injection has higher efficacy of pain and inflammation reduction in the early phase of the disease.

Biochemical and physical actions of hyaluronic acid delivered by intradermal jet injection route

Administration of exogenous hyaluronic acid (HA) by liquid jet injection is considered as a beneficial therapy for dermatology conditions. This paper reviews variety of the factors which would optimize the clinical output of hyaluronic acid in this treatment modality. A pneumatically accelerated jet penetrates the epidermis and spherically spreads micro-droplets of HA in the dermis without significant damage to the tissue and blood vessels. Kinetic energy of the jet activates two parallel mechanisms of action-mechanical and biological-which act synergistically to initiate and augment the regenerative effect. Jet-induced micro-trauma stimulates collagen synthesis and tissue repair without inflammation. Aside from the biophysical stimulation of dermal fibroblast, the biomolecular properties of exogenous HA provide excellent clinical results for skin atrophy, remodeling of dermal scarring, and reverse formation of fibrotic tissue. The effect is mediated by HA-specific cell receptors and depends on molecular weight and the rheological properties of HA polymer. Skin mechanical properties play a key role in predicting HA dispersion patterns. Tolerability and safety of the treatment approach are determined by the jet's physical impact on the tissue and/or by the safety profile of the injected material. Although pneumatic jet delivery of a hyaluronic acid has a limited use in clinical practice, this treatment approach has a strong potential for extended implementation in esthetic dermatology. The synergistic mechanism has significant advantages of predictable and rapid clinical outcomes with a low discomfort. Additional well-designed investigations are required for establishing a scientific foundation and guidelines for this treatment modality.

Corticosteroid Injections May Increase Retear and Revision Rates of Rotator Cuff Repair: A Systematic Review

PURPOSE

To synthesize the clinical outcome data of preoperative and postoperative corticosteroid injections (CIs) and their effect on rotator cuff repairs (RCRs).

METHODS

A systematic review was performed to identify studies that reported the results or clinical outcomes of RCRs in patients receiving either preoperative or postoperative CIs. The searches were performed using MEDLINE, Google Scholar, and Embase, and studies were chosen following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines.

RESULTS

A total of 11 studies were included with data for 176,352 shoulders: 6 studies involving 175,256 shoulders with data regarding preoperative CIs, 4 studies involving 1,096 shoulders with data regarding postoperative CIs, and 1 study with 212 shoulders containing preoperative and postoperative data. Preoperative CIs were found in 3 studies to increase the risk of revision surgery when administered within 6 months (odds ratio [OR], 1.38-1.82) and up to 1 year (OR, 1.12-1.52) prior to RCR, with revision rates in 2 studies being highest when patients received 2 or more injections (OR, 2.12-3.26) in the prior year. Postoperative CIs reduced pain and improved functional outcomes in 5 studies without increasing the retear rates (5.7%-19% for CI and 14%-18.4% for control) in most studies.

CONCLUSIONS

CIs provide benefit by relieving pain and improving functional outcome scores. However, repeated preoperative CIs may increase retear rates and the likelihood of revision surgery. A lower frequency of CI and longer preoperative waiting period after CI should be considered to decrease such risks. Postoperative CIs several weeks after RCR do not appear to increase retear rates.

LEVEL OF EVIDENCE

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

A Review of Current Keloid Management: Mainstay Monotherapies and Emerging Approaches

Commonly affecting those with skin of color, keloids are an aberrant wound response that leads to wound tissue expanding above and beyond the original cutaneous injury. Keloids are notoriously and particularly difficult to treat because of their tendency to recur after excision. The current standard of care is intralesional steroid (triamcinolone acetonide). However, because no therapy has yet proven to be fully curative, keloid treatments have expanded to include a number of options, from injections to multimodal approaches. This review details current treatment of keloids with injections (bleomycin, verapamil, hyaluronic acid and hyaluronidase, botulinum toxin, and collagenase), cryotherapy, laser, radiofrequency ablation, radiation, extracorporeal shockwave therapy, pentoxifylline, and dupilumab.

Preoperative hyaluronic acid injection modulates postoperative functional outcome in patients undergoing arthroscopic rotator cuff repair

Background

Arthroscopic rotator cuff repair (ARCR) generally yields acceptable clinical results. Hyaluronic acid (HA), a high-molecular-weight polysaccharide, is present in the extracellular matrix of soft connective tissue and synovial fluid, and its injection is known to significantly improve pain and clinical outcomes after rotator cuff injury. Some studies have described the role of HA injections as conservative therapy for rotator cuff tears. Since the subacromial bursa is believed to be the main source of shoulder pain in rotator cuff tears, subacromial injection is frequently used before surgery; however, its relationship with the clinical outcome after surgery remains unclarified. Therefore, we aimed to examine effects of preoperative subacromial HA injection on postoperative clinical outcome in patients with ARCR.

Methods

Ninety-eight patients were divided into a HA injection group and a non-injection group. The functional outcome measured was the University of California, Los Angeles (UCLA) score. Univariate analysis was performed to obtain variables with p values less than 0.1; we then used propensity score analysis, adjusting for pre- and post-operative confounding factors.

Results

The UCLA scores of all patients significantly improved 1 year postoperatively (PO) (p < 0.05). Subacromial HA injections were performed in patients with worse preoperative function. Univariate analysis showed significantly greater improvements in the injection group than in the non-injection group in terms of preoperative UCLA score, trauma, diabetes mellitus, UCLA score 3 months PO, abduction strength 4 months PO, and internal rotation (IR) strength 6 and 12 months PO. Propensity score analysis demonstrated that UCLA scores 3 months PO and IR strength 12 months PO in the injection group were significantly greater than those in the non-injection group. There were no significant differences in postoperative re-tear rates between the groups. In sub-analysis of the injection group, propensity scores showed that concurrent use of local anesthetics did not affect the data, suggesting that HA was effective.

Conclusion

Subacromial injection was administered to patients with worse function before ARCR. Propensity score analysis successfully demonstrated that functional outcome after surgery was improved in patients who were administered this injection compared with patients who were not administered this injection before surgery.

Adverse Impact of Corticosteroid Injection on Rotator Cuff Tendon Health and Repair: A Systematic Review

PURPOSE

To assess adverse effects of preoperative corticosteroid injections (CSIs) in patients with rotator cuff disease, especially before rotator cuff repair (RCR).

METHODS

A systematic review of the MEDLINE database was performed according to guidelines from the Preferred Reporting Item for Systematic Reviews and Meta-Analyses for all studies reporting on adverse clinical effects of CSIs on rotator cuff tendon.

RESULTS

A total of 8 articles were identified that report on adverse outcomes and risks associated with corticosteroid injections in the setting of rotator cuff tendinosis. Among these included articles, a single CSI for rotator cuff tendinosis was associated with increased risk of revision rotator cuff repair (odds ratio [OR]: range 1.3 [1.1-1.7] to 2.8 [2.2-3.4]) when administered up to a year before surgery and postoperative infections (OR: 2.1 [1.5-2.7]) when administered within a month before RCR. The risk of adverse outcomes after rotator cuff repair are greatest if a CSI is administered within 6 months of surgery (OR: 1.8 [1.3-2.6]) or if ≥2 injections are given within a year of surgery (OR: range 2.1 [1.8-2.5] to 3.3 [2.7-4.0]).

CONCLUSION

Several recent clinical trials have demonstrated that CSIs are correlated with increased risk of revision surgery after RCR in a temporal and dose dependent matter. Caution should be taken when deciding to inject a patient, and this treatment should be withheld if an RCR is to be performed within the following 6 months.

LEVEL OF EVIDENCE

IV, systematic review of Level III and IV studies.

Adverse Impact of Corticosteroids on Rotator Cuff Tendon Health and Repair: A Systematic Review of Basic Science Studies

Purpose

To evaluate the in vitro effects of corticosteroid injections (CSIs) on rotator cuff tendon (RCT).

Methods

A systematic review of the MEDLINE database was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for all studies reporting on adverse biochemical and biomechanical effects of CSIs on RCT.

Results

Sixteen studies were identified that had been published in the last 15 years on the effects of corticosteroids on RCTs. Eight of these studies were on human RCTs, 6 were on rat tendons, 1 considered both human and rat tendons, and 1 was on dog tendon. Five studies analyzed the effects of corticosteroids on the biomechanical properties of RCT or rotator cuff repair, whereas the remaining observed the cellular and molecular effects of CSIs on RCT. Corticosteroids suppress an inflammatory response, induce apoptosis, and have negative effects on collagen and tendon cell viability in RCTs. The mechanical properties, including load to failure of RCTs and rotator cuff repair anchor pull-out strength, also are decreased by CSIs. These in vitro effects appear to be transient as well as frequency and dose dependent.

Conclusions

On a molecular level, CSIs decrease cellular proliferation, alter collagen and extracellular matrix composition, impede inflammatory pathways, decrease cellular viability, increase adipocyte differentiation, and increase apoptosis. These changes can be seen as early as 24 hours after corticosteroid exposure, last as long as 2 to 3 weeks, and are exacerbated by increased doses and decreased latency between doses. Biomechanical studies demonstrate that these changes result in decreased maximal load to failure, tendon stiffness, and suture anchor pull-out strength in rat shoulders up to 2 weeks but not at 3 and 4 weeks, post-CSI.

Clinical Relevance

Shoulder subacromial steroid injection is common, and practitioners should be aware of results both positive and deleterious.

Ultrasound-Guided Injection of High Molecular Weight Hyaluronic Acid versus Corticosteroid in Management of Plantar Fasciitis: A 24-Week Randomized Clinical Trial

BACKGROUND AND AIMS

Plantar fasciitis (PF) is the leading cause of heel pain in adults. This study was designed to evaluate the effect of hyaluronic acid (HA) injection in reducing the symptoms of PF, compared with corticosteroid (CS) injection as a conventional treatment.

METHODS

In this triple-blind, randomized, clinical trial, 75 patients who had the symptoms of PF for at least 3 months were randomly divided into two groups of 38 and 37 individuals. Then, each patient received either a single injection of high molecular weight (>2000 kDa) HA (1 mL HA 20 mg + 1 mL lidocaine 2%) or CS (1 mL methylprednisolone 40 mg + 1 mL lidocaine 2%) under the ultrasonography (US) guidance. Visual analog scale (VAS), foot ankle ability index (FAAI), pressure pain threshold (PPT), functional foot index (FFI), and plantar fascia thickness (PFT) were measured using US at baseline, 6 weeks and 24 weeks after the injection. Eventually, at the end of the treatment period, the patients' satisfaction was measured. Intention to treat analysis was used to assess the results.

RESULTS

After 24 weeks of follow-up, results from 60 subjects were fully obtained; however, results of 73 patients included into intention to treat analysis in the sixth-week follow-up. In both groups, VAS, PFT and FFI decreased, while FAAI and PPT increased significantly (P <0.001). At the baseline and at the 24th-week, no significant difference between the two groups was observed in any of the variables. However, a comparison between the baseline and the sixth-week results shows a prominent decrease in PPT and PFT in the CS group compared to the HA group (P = 0.004 and P = 0.011). Finally, there were no statistical differences between the two groups in treatment satisfaction (P = 0.618).

CONCLUSION

Both CS and HA were effective modalities for PF and can improve pain and function with no superiority in 24th-week follow-ups, although CS seems to have a faster trend of improvement in the short term.

Intra-articular treatment with corticosteroids increases apoptosis in human rotator cuff tears

PURPOSE

The aim of this study is to evaluate in vivo the level of apoptosis in human rotator cuff tears and the relationship it might have with tendon degeneration.

METHODS

Rotator cuff biopsies from 19 male and female patients, ages between 38 and 68 years, with and without previous corticosteroid infiltrations were collected via arthroscopy. Biopsies from seven patients with healthy rotator cuffs were used as a control group. An in situ terminal deoxynucleotidyl transferase dUTP nick end labeling assay was performed to detect the level of apoptosis, which was expressed as a percentage of apoptotic cells (PAC).

RESULTS

PAC in patients with corticosteroid infiltrations was 76.97 ± 16.99 in all tendon rupture zones, in non-infiltrated patients was 35.89 ± 22.96, whereas in control patients was 14.48 ± 8.15. Likewise, the tendency of PAC reveals that apoptosis in control and non-infiltrated groups was different and dispersed in all tear zones; while in corticosteroid treated patients, the tendency was similar in all rupture sites.

CONCLUSIONS

This investigation leads us to conclude that the administration of corticosteroid is associated with a higher amount of apoptosis at the insertion site of the rotator cuff (rupture edge).

Preoperative Shoulder Injections Are Associated With Increased Risk of Revision Rotator Cuff Repair

PURPOSE

The goal of this study was to determine whether the timing of preoperative shoulder injections is associated with an increased risk of revision rotator cuff repair following primary rotator cuff repair (RCR).

METHODS

A retrospective analysis of claims data of privately insured subjects from the MarketScan database for the years 2010 to 2014 was conducted. Multivariable logistic regression models were used to compare the odds of reoperation between groups. Laterality for the injection, index procedure, and subsequent surgery were verified for all subjects.

RESULTS

A total of 4,959 subjects with an arthroscopic RCR were identified, 392 of whom required revision RCR within the following 3 years. Patients who had an injection within 6 months preceding the index surgery were at a much higher risk of undergoing reoperation for revision RCR: 0 to 3 months prior, adjusted odds ratio (AOR) 1.375 (95% confidence interval [CI], 1.027-1.840); 3 to 6 months prior, AOR 1.822 (95% CI, 1.290-2.573); and 6 to 12 months prior, AOR 1.237 (95% CI, 0.787-1.943).

CONCLUSIONS

Patients who had received an injection within 6 months prior to RCR were much more likely to undergo a revision cuff repair within the following 3 years. The risk of reoperation significantly declines if there is more than 6 months between injection and RCR. Consideration should be given to minimizing preoperative injections in patients requiring RCR or delaying primary RCR for 6 months following injection.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Effects of Estrogen-Deficient State on Rotator Cuff Healing

BACKGROUND

Rotator cuff retears after surgical repair are a concern, despite advances in operative techniques, but few studies have investigated the effects of the estrogen-deficient state on tendon-to-bone healing at the repair site.

PURPOSE

We evaluated the effect of the estrogen-deficient state on tendon-to-bone healing after rotator cuff repair in an ovariectomized rat model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Female Sprague Dawley rats underwent detachment and immediate repair of the supraspinatus tendon. Surgery was performed in 24 rats at 4.5 weeks of age 17 weeks after ovariectomy (OVX group) and in 24 age-matched control rats without ovariectomy (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks after surgery for biomechanical and histological evaluations of reattachment. Bone mineral density (BMD) at the insertion site and cancellous bone in the humeral head was assessed by micro-computed tomography.

RESULTS

BMD was significantly lower both at the insertion site and in cancellous area in the OVX group than in the control group at weeks 2 to 12. Ultimate load to failure, ultimate stress, linear stiffness, and the Young modulus were significantly lower in the OVX group than in the control group at 2 and 4 weeks, but the difference was no longer significant at 8 and 12 weeks. At 2 and 4 weeks, relatively immature granulation tissue was observed in the OVX group compared with the control group. At 8 and 12 weeks after surgery, there were differences in the tendon-bone interface in the 2 groups: Direct insertion with well-established chondroid tissue was seen in the control group, and indirect insertion without chondroid tissue was seen in the OVX group. Consistently, the amount of chondroid tissue was greater and collagen organization was better in the control group than in the OVX group. Cells expressing cathepsin K were significantly more numerous both at the insertion site and in cancellous bone in the OVX group than in the control group.

CONCLUSION

The estrogen-deficient state by ovariectomy, compared with control rats, led to decreased biomechanical properties and poor development of chondroid tissue that influenced the repair of the tendon insertion after surgery.

CLINICAL RELEVANCE

Agents that modulate bone metabolism might improve tendon-to-bone healing in patients with an estrogen-deficient state, such as postmenopausal women who undergo rotator cuff surgery.

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.

Systemic corticosteroids improve tendon healing when given after the early inflammatory phase

Inflammation initiates tendon healing and then normally resolves more or less completely. Unresolved inflammation might disturb the remodeling process. We hypothesized that suppression of inflammation during the early remodeling phase by systemic dexamethasone treatment can improve healing. 36 rats underwent Achilles tendon transection and were randomized to dexamethasone or saline on days 0-4 after surgery (early inflammatory phase), and euthanasia day 7. Another 54 rats received injections days 5-9 (early remodeling phase) and were euthanized day 12 for mechanical, histological and flow cytometric evaluation. Dexamethasone treatment days 0-4 reduced the cross-sectional area, peak force and stiffness by day 7 to less than half (p < 0.001 for all), while material properties (peak stress and elastic modulus) were not significantly affected. In contrast, dexamethasone treatment days 5-9 increased peak force by 39% (p = 0.002) and stiffness by 58% (p < 0.001). The cross-sectional area was reduced by 42% (p < 0.001). Peak stress and elastic modulus were more than doubled (p < 0.001 for both). Semi-quantitative histology at day 12 showed that late dexamethasone treatment improved collagen alignment, and flow cytometry revealed reduced numbers of CD8a+ cytotoxic T cells in the tendon callus. These results suggest that downregulation of lingering inflammation during the early remodeling phase can improve healing.

Pre-operative corticosteroid injections improve functional outcomes in patients undergoing arthroscopic repair of high-grade partial-thickness rotator cuff tears

BACKGROUND

Subacromial corticosteroid injections (CSI's) are a common non-surgical treatment for rotator cuff tears. Few studies have assessed the effects of pre-operative CSI's on postoperative functional outcomes.

METHODS

A retrospective analysis was conducted of 132 patients with high-grade, partial-thickness rotator cuff tears (PTRCT's). The subjects were divided into two groups based on whether they received a CSI or not. The CSI group was further divided into three subgroups based on when they received a pre-operative injection: 0-3 months, 3-6 months, >6 months before surgery. The Visual Analog Scores (VAS), American Shoulder and Elbow Surgeon scores (ASES), and Constant scores were recorded prior to surgery and at a one-year post-operative follow-up appointment for each subject.

RESULTS

Patients who received a pre-operative CSI (n=92) improved significantly more than the non-injection group (n=40) in all outcome measures. The 0-3 months injection subgroup experienced a significant increase in ASES and Constant score (p=0.019 and 0.014, respectively) compared to the other two subgroups, but the VAS score decrease only trended toward significance (p=0.091). The sample as a whole experienced significant improvement in all three outcome measures.

CONCLUSION

Patients undergoing arthroscopic repair of a high-grade PTRCT may benefit from a pre-operative CSI 0-3 months before surgery.

LEVEL OF EVIDENCE

IIb.

Apoptosis and rotator cuff tears: scientific evidence from basic science to clinical findings

INTRODUCTION

Excessive apoptosis has been hypothesized as possible cause of tendinopathy and tear in the tendons of the rotator cuff (RC). Different mechanisms and molecules play a key role in cell regulation. Biological interventions can affect the process of apoptosis to control the tendinopathy process, and may be useful to design new treatments.

SOURCE OF DATA

We identified basic science, in vitro and in vivo preclinical and clinical studies listed in the Pubmed Google Scholar, CINAHL, Cochrane Central and Embase Biomedical databases in English, Spanish, Italian and French concerning the effects of apoptosis on RC tendons.

AREAS OF AGREEMENT

The homeostasis between the apoptotic and inflammatory processes is dynamic and controlled by pro- and anti-apoptotic mechanisms and signals, with variable balance in different areas of the RC tendons in human specimens.

AREAS OF CONTROVERSY

Apoptosis can be identified along the whole tendon, not only in the area of the lesion. Therefore, it is not necessary to undertake wide debridement of the torn edges of the tendon when undertaking a repair.

GROWING POINTS

The identification of the various factors that control apoptosis and its mechanisms can help to design new treatments and exert positive effects in the recovery from tendon tears.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies are needed to produce clear guidelines to determine how to balance the apoptosis process to reduce the failed healing response found in non-traumatic RC tears.

Three or more preoperative injections is the most significant risk factor for revision surgery after operative treatment of lateral epicondylitis: an analysis of 3863 patients

BACKGROUND

This study was conducted to identify the rate of failure of operative treatment of lateral epicondylitis, defined as progression to ipsilateral revision surgery, and associated patient-specific risk factors for failure.

METHODS

A national database was used to identify patients undergoing surgical treatment of lateral epicondylitis from 2005 to 2012. Patients undergoing concomitant procedures were excluded. Patients who then required subsequent ipsilateral extensor carpi radialis brevis débridement or release within 2 years were identified using similar methods. A multivariate binomial logistic regression analysis was used to evaluate patient-related risk factors for revision surgery. In addition, the number of preoperative injections (1, 2, or ≥3) in the ipsilateral elbow was identified and included in the regression analysis. Adjusted odds ratios (OR) and 95% confidence intervals were calculated for each risk factor.

RESULTS

Of 3863 patients who underwent operative treatment of lateral epicondylitis, 58 (1.5%) required ipsilateral revision surgery. Risk factors for revision surgery included age <65 years (OR, 2.95; P = .003), male gender (OR, 1.53; P = .017), morbid obesity (OR, 2.13; P = .002), tobacco use (OR, 1.87; P < .001), and inflammatory arthritis (OR, 1.79; P = .009). Having ≥3 ipsilateral preoperative injections was the most significant risk factor (OR, 3.55; P < .001), whereas having 2 (OR, 1.44; P = .135) or 1 (OR, 1.15; P = .495) was not significant.

CONCLUSIONS

The incidence of failure requiring revision surgery for lateral epicondylitis in the studied population is low (1.5%). Risk factors for revision surgery include younger age, male gender, morbid obesity, tobacco use, and inflammatory arthritis. The most significant risk factor for revision surgery is having ≥3 ipsilateral preoperative injections.

The Effect of Sodium Hyaluronate on Ligamentation and Biomechanical Property of Tendon in Repair of Achilles Tendon Defect with Polyethylene Terephthalate Artificial Ligament: A Rabbit Tendon Repair Model

The Achilles tendon is the most common ruptured tendon of human body. Reconstruction with polyethylene terephthalate (PET) artificial ligament is recommended in some serious cases. Sodium hyaluronate (HA) is beneficial for the healing of tendon injuries. We aimed to determine the effect of sodium hyaluronate in repair of Achilles tendon defect with PET artificial ligament in an animal tendon repair model. Sixteen New Zealand White rabbits were divided into two groups. Eight rabbits repaired with PET were assigned to PET group; the other eight rabbits repaired with PET along with injection of HE were assigned to HA-PET group. All rabbits were sacrificed at 4 and 8 weeks postoperatively for biomechanical and histological examination. The HA-PET group revealed higher biomechanical property compared with the PET group. Histologically, more collagen tissues grew into the HA-PET group compared with PET group. In conclusion, application of sodium hyaluronate can improve the healing of Achilles tendon reconstruction with polyethylene terephthalate artificial ligament.

Histomorphometric and ultrastructural analysis of the tendon-bone interface after rotator cuff repair in a rat model

Successful rotator cuff repair requires biological anchoring of the repaired tendon to the bone. However, the histological structure of the repaired tendon-bone interface differs from that of a normal tendon insertion. We analysed differences between the normal tendon insertion and the repaired tendon-bone interface after surgery in the mechanical properties, histomorphometric analysis, and 3-dimensional ultrastructure of the cells using a rat rotator cuff repair model. Twenty-four adult Sprague-Dawley (SD) rats underwent complete cuff tear and subsequent repair of the supraspinatus tendon. The repaired tendon-bone interface was evaluated at 4, 8, and 12 weeks after surgery. At each time point, shoulders underwent micro-computed tomography scanning and biomechanical testing (N = 6), conventional histology and histomorphometric analysis (N = 6), and ultrastructural analysis with focused ion beam/scanning electron microscope (FIB/SEM) tomography (N = 4). We demonstrated that the cellular distribution between the repaired tendon and bone at 12 weeks after surgery bore similarities to the normal tendon insertion. However, the ultrastructure of the cells at any time point had a different morphology than those of the normal tendon insertion. These morphological differences affect the healing process, partly contributing to re-tearing at the repair site. These results may facilitate future studies of the regeneration of a normal tendon insertion.

Hyaluronic acid and tendon lesions

INTRODUCTION

recently, the viscoelastic properties of hyaluronic acid (HA) on liquid connective tissue have been proposed for the treatment of tendinopathies. Some fundamental studies show encouraging results on hyaluronic acid's ability to promote tendon gliding and reduce adhesion as well as to improve tendon architectural organisation. Some observations also support its use in a clinical setting to improve pain and function. This literature review analyses studies relating to the use of hyaluronic acid in the treatment of tendinopathies.

METHODS

this review was constructed using the Medline database via Pubmed, Scopus and Google Scholar. The key words hyaluronic acid, tendon and tendinopathy were used for the research.

RESULTS

in total, 28 articles (in English and French) on the application of hyaluronic acid to tendons were selected for their relevance and scientific quality, including 13 for the in vitro part, 7 for the in vivo animal part and 8 for the human section.

CONCLUSIONS

preclinical studies demonstrate encouraging results: HA permits tendon gliding, reduces adhesions, creates better tendon architectural organisation and limits inflammation. These laboratory observations appear to be supported by limited but encouraging short-term clinical results on pain and function. However, controlled randomised studies are still needed.