Hyaluronic acid modulates cell proliferation unequally in intrasynovial and extrasynovial rabbit tendons in vitro

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.

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.

Tendon grafts: their natural history, biology and future development

The use of tendon grafts has diminished as regimes of primary repairs and rehabilitation have improved, but they remain important in secondary reconstruction. Relatively little is known about the cellular biology of grafts, and the general perception is that they have little biological activity. The reality is that there is a wealth of cellular and molecular changes occurring with the process of engraftment that affect the quality of the repair. This review highlights the historical perspectives and modern concepts of graft take, reviews the different attachment techniques and revisits the biology of pseudosheath formation. In addition, we discuss some of the future directions in tendon reconstruction by grafting, which include surface modification, vascularized tendon transfer, allografts, biomaterials and cell-based therapies.

Ultrasound-guided percutaneous injection to treat de Quervain's disease using three different techniques: a randomized controlled trial

PURPOSE

To compare the six-month outcome of three different ultrasound-guided treatments for de Quervain's disease (DQD).

METHODS

We prospectively treated 75 consecutive patients (51 females, 24 males, mean age ± standard deviation = 45.3 ± 9.8 years) with DQD. Patients' features (hand dominance, intraretinaculum septum, accessory tendons) were recorded. Visual analogue scale (VAS), reduced disability (quickDASH) score, and retinaculum thickness were evaluated at baseline and after one (excluding retinaculum thickness), three, and six months. Patients were randomized into three groups of 25 patients each treated under ultrasound guidance: Group A (1 ml methylprednisolone acetate; mean baseline thickness = 1.6 mm; mean baseline VAS = 6; mean baseline quickDASH = 55); Group B (1 ml methylprednisolone acetate +15-day delayed 2 ml saline 0.9 %; 1.4; 6; 56); Group C (1 ml methylprednisolone acetate +15-day delayed 2 ml low molecular weight hyaluronic acid; 1.7; 6; 55).

RESULTS

After one month results were: Group A mean VAS = 2; mean quickDASH = 23; Group B 2; 22; Group C 2; 21. After three months results were: Group A retinaculum thickness = 0.7 mm; 3; 27); Group B 0.8 mm; 1; 25; Group C 0.5 mm; 1; 23. After six months results were: Group A 1.5 mm; 3; 51; Group B 1 mm; 2; 51; Group C 0.7 mm; 1; 26 (P < 0.001 for all vs. baseline). Patients' age, sex, hand dominance, presence of subcompartment dividing septum, and supernumerary tendons had no influence on outcome (P  ≥  0.177).

CONCLUSION

Addition of hyaluronic acid to ultrasound-guided injections of steroids to treat DQD seems to improve the outcome and to reduce the recurrence rate.

KEY POINTS

• Ultrasound guidance allows for safe injection procedures to treat de Quervains' disease • Steroid injections allow prompt recovery in de Quervain's disease with short-term recurrence • Addition of hyaluronic acid allows recurrence rate reduction compared to simple steroid injections.

In vitro evaluation of cytotoxicity of hyaluronic acid as an extracellular matrix on OFCOL II cells by the MTT assay

OBJECTIVE

To evaluate the cytotoxicity of hyaluronic acid (HA) on a tissue-engineered compound for bone grafting containing osteoblastic cells (OFCOL II), platelet-rich plasma (PRP) with or without thrombin (Thr), and hydroxyapatite (HP) by the MTT assay.

STUDY DESIGN

Studied groups were formed as follows: (A) Cells + HA + PRP with Thr + hydroxyapatite (HP); (B) Cells + HA + PRP + HP; (C) Cells + HA + HP; (D) Cells + HP; (E) Cells + HA; (F) Cells + PRP with Thr; (G) Cells + PRP; and (H) Pure Dulbecco's modified Eagle's medium (DMEM) with 15% fetal bovine serum. A 2-way ANOVA and Tukey's test were applied for statistical analysis (P < .05).

RESULTS

Results of cell viability for each group were as follows: A: 79%, B: 67%, C: 68%, D: 99%, E: 74%, G: 89%, F: 90%, and Group H: 100%.

CONCLUSIONS

Results suggested a decrease in cell viability in the presence of HA.

Ultrasound-guided injection of a corticosteroid and hyaluronic acid: a potential new approach to the treatment of trigger finger

Background and Objectives: Stenosing tenosynovitis (trigger finger) is one of the most common causes of pain and disability in the hand, which may often require treatment with anti-inflammatory drugs, corticosteroid injection, or open surgery. However, there is still large room for improvement in the treatment of this condition by corticosteroid injection. The mechanical, viscoelastic, and antinociceptive properties of hyaluronic acid may potentially support the use of this molecule in association with corticosteroids for the treatment of trigger finger. This study examines the feasibility and safety of ultrasound-guided injection of a corticosteroid and hyaluronic acid compared, for the first time, with open surgery for the treatment of trigger finger.

Methods: This was a monocentric, open-label, randomized study. Consecutive patients aged between 35 and 70 years with ultrasound-confirmed diagnosis of trigger finger were included. Patients were randomly assigned to either ultrasound-guided injection of methylprednisolone acetate 40 mg/mL with 0.8mL lidocaine into the flexor sheath plus injection of 1mL hyaluronic acid 0.8% 10 days later (n = 15; group A), or to open surgical release of the first annular pulley (n = 15; group B). Clinical assessment of the digital articular chain was conducted prior to treatment and after 6 weeks, and 3, 6, and 12 months. The duration of abstention from work and/or sports activity, and any treatment complications or additional treatment requirements (e.g. physiotherapy, compression, medication) were also recorded.

Results: Fourteen patients (93.3%) in group A had complete symptom resolution at 6 months, which persisted for 12 months in 11 patients (73.3%), while three patients experienced recurrences and one experienced no symptom improvements. No patients in group A reported major or minor complications during or after corticosteroid injection, or required a compression bandage. All 15 patients in group B achieved complete resolution of articular impairment by 3 weeks after surgery, but ten patients were assigned to physiotherapy and local and/or oral analgesics for complete resolution of symptoms, which was approximately 30–40 days postsurgery. The mean duration of abstention from work and/or sport was 2–3 days in group A and 26 days in group B.

Conclusions: Although the limited sample size did not allow any statistical comparison between treatment groups, and therefore all the findings should be regarded as preliminary, the results of this explorative study suggest that ultrasound-guided injection of a corticosteroid and hyaluronic acid could be a safe and feasible approach for the treatment of trigger finger. It is also associated with a shorter recovery time than open surgery, which leads to a reduced abstention from sports and, in particular, work activities, and therefore may have some pharmacoeconomic implications, which may be further explored. In light of the promising results obtained in this investigation, further studies comparing ultrasound-guided injection of corticosteroid plus hyaluronic acid with corticosteroid alone are recommended in order to clarify the actual benefits attributable to hyaluronic acid.

ROLE OF THE HYALURONAN-PRODUCING TENOSYNOVIUM IN PREVENTING ADHESION FORMATION DURING HEALING OF FLEXOR TENDON INJURIES

Flexor tendons of white Leghorn chickens (n = 25) were used for this study. One chicken was used as a normal control (no surgery), and the remaining 24 were used for experiments. After partial tendon-severing in both legs of 24 chickens, the right and the left leg were treated differently, thereby creating two groups: Group I, in which the tenosynovium was preserved, and Group II, in which the tenosynovium was removed. Hematoxylin-eosin staining was performed to observe adhesions; immunohistochemical analysis was used to localize HA. HA production was noted in granulation tissue invading between the tendon stumps in both groups; however, HA expression in the tenosynovium was observed only in Group I where adhesion formation was minimal. The HA-producing tenosynovium plays a crucial role in preventing adhesion formation in this model of flexor tendon injuries.

Effects of human amniotic fluid and membrane in the treatment of Achilles tendon ruptures in locally corticosteroid-induced Achilles tendinosis: an experimental study on rats

BACKGROUND

To determine the effects of human amniotic fluid and membrane in the treatment of Achilles tendon ruptures, 72 tendons of 36 Wistar rats were injected with betamethasone sodium phosphate.

METHODS

By the end of fourth week, both tendons were tenotomized and repaired, then the samples were divided into three groups. The first group was left untreated after suturing. Human amniotic fluid was injected to the second and amniotic fluid and membrane were both administered to the third group. Twenty-four tendons were scored at the end of the first week, and 24 at the end of the second week histopathologically, and 24 biomechanically at the end of the third week.

RESULTS

There was a significant statistical difference only between the histopathological results of Groups 2 and 3 at the first week.

CONCLUSIONS

Human amniotic membrane and fluid do not add anything to the healing process of Achilles tendon ruptures in the early phase.

Mechanical properties of intrasynovial and extrasynovial tendon fascicles

BACKGROUND

Tendon grafting in tendon reconstruction often involves the interchange of intrasynovial and extrasynovial tendons. Although many studies have examined the cellular and biological differences between tendons of various sources, few have studied the mechanical properties of these two different types of tendons. The purpose of this study was to investigate the mechanical properties of intrasynovial and extrasynovial tendons.

METHODS

Canine peroneus longus (extrasynovial) and flexor digitorum profundus (intrasynovial) tendons, further subdivided into intrasynovial tendinous and intrasynovial fibrocartilaginous segments, were used in the study. An indentation test was used to measure the compressive modulus. Tensile testing was performed on 400mum longitudinal sections.

FINDINGS

The compressive modulus of the intrasynovial fibrocartilaginous segment was significantly higher than that of the intrasynovial tendinous segment, which was in turn significantly higher than that of the extrasynovial tendon (P<0.0001). The tensile modulus of extrasynovial tendon was significantly higher than that of intrasynovial fibrocartilaginous and intrasynovial tendinous segments (P<0.005). The tensile modulus of the intrasynovial fibrocartilaginous and tendinous segments was not significantly different (P=0.14).

INTERPRETATION

The results suggest that extrasynovial tendons exhibit superior tensile properties but inferior compressive properties when compared to intrasynovial tendons, which is consistent with their biological role in situ, but which could lead to complications when these tendons are repositioned during tendon graft surgery.

Effects of hyaluronan on cell proliferation and mRNA expression of procollagens alpha 1 (I) and alpha 1 (III) in tendon-derived fibroblasts from patients with rotator cuff disease: an in vitro study

BACKGROUND

Hyaluronan (HA) improves postoperative recovery after flexor tendon surgery, preventing postoperative adhesion. However, its influence on the rotator cuff tendon after cuff repair has not yet been clarified in detail.

HYPOTHESIS

Hyaluronan is likely to modulate cell proliferation and mRNA expression of procollagens alpha1 (I) and alpha1 (III) in tendon-derived fibroblasts in patients with rotator cuff disease.

STUDY DESIGN

Controlled laboratory study.

METHODS

The study subjects were 10 patients with rotator cuff disease, with an average age of 62 years (range, 44-72). Various concentrations of HA (1.0-5.0 mg/mL) were added to monolayer-cultured tendon-derived fibroblasts from these patients. Hyaluronan binding and CD44 expression on the tendon-derived fibroblasts were evaluated by confocal microscopy using fluorescein-conjugated HA and antihuman CD44 antibody (OS/37). Cell proliferation was evaluated by recording changes in cell number. The levels of expression of procollagen alpha1 (I) and alpha1 (III) mRNA were measured by real-time reverse transcriptase polymerase chain reaction.

RESULTS

Immunofluorescence cytochemistry detected constitutive binding of HA and CD44 expression on the tendon-derived cells. Treatment with various concentrations of HA significantly inhibited cell proliferation and decreased the expression level of procollagen alpha1 (III) mRNA, but not that of procollagen alpha1 (I) mRNA, in the tendon-derived fibroblasts.

CONCLUSION

Hyaluronan modulates cell proliferation and the expression level of procollagen alpha1 (III) mRNA, but not that of pro-collagen alpha1 (I), in fibroblasts from patients with rotator cuff disease.

CLINICAL RELEVANCE

Postoperative use of exogenous HA may allow the healing of a repaired rotator cuff tendon with minimal adhesion.

The inflammatory response and hyaluronan synthases in the rabbit flexor tendon and tendon sheath following injury

Using a rabbit model of flexor tendon injury, mRNA levels for a subset of relevant molecules involved in inflammatory and fibrotic processes were assessed by reverse transcriptase-polymerase chain reaction 3, 6, 12 and 24 days after injury. Increased levels of COX-2, IL-1beta, MMP-13 and TIMP-1 mRNA were detected in both tendon and tendon sheath following injury, with each molecule exhibiting tissue and time-dependent changes. MMP-13 and TIMP-1 mRNA levels were markedly upregulated in both tissues, whereas COX-2 and IL-1beta predominantly increased in tendon. Both hyaluronan synthase (HAS) 2 and 3 exhibited increases in mRNA levels in tendon tissue after injury, HAS 2 being more pronounced. These findings support the concept that healing in the flexor tendon and the sheath involve different molecular events and that each tissue may require unique modifications if healing is to be enhanced and adhesions reduced.

Sodium hyaluronate regulating angiogenesis during Achilles tendon healing

The aim of this study was to evaluate the effect of SH (sodium hyaluronate-NaHA) on vascular endothelial growth factor (VEGF) and type IV collagen expression during the Achilles-tendon healing process. Adult New Zealand white rabbits (n=32) aged 4 months and weighing 2.7-3.9 kg were used. The rabbits were randomly divided into two groups, and each group was divided into two subgroups and monitored for 6 and 12 weeks. Tendo calcanei were incised transversely and repaired. An injection of 0.5 ml NaHA (15 mg/ml) was administered between the tendon and paratenon of the right leg and repeated twice at one-week intervals. Equal numbers of animals were sacrificed at the 6th and 12th weeks, and the repaired tissue was examined macroscopically and histologically for the presence of VEGF and type IV collagen expression every week. The decrease in the amount of adhesion tissue and the acceleration of tendon healing in the NaHA group were significantly high when compared with control groups at 6 and 12 weeks (p<0.001, p<0.05). In the NaHA group, due to vascular proliferation VEGF immunostaining was strongly positive in the 6th week (p<0.05), and remained positive in the 12th week (p<0.05). Similar immunostaining findings were detected for type IV collagen in the 6th week. However, there was a significant decline in immunostaining rate in the 12th week (p<0.05). The increases in VEGF and type IV collagen expression following SH administration might be an indication that SH may partly be involved in regulation of angiogenesis.

Hyaluronic acid of high molecular weight inhibits proliferation and induces cell death in U937 macrophage cells

Hyaluronic acid (HA), a major glycosaminoglycan component of the extracellular matrix, has regulatory influences on cells and cellular activities. To explore the effects of a high concentration (1 mg/mL) of high molecular weight HA (500-730 kD) on U937 macrophage growth dynamics, three factors that influence overall cellular growth, namely proliferation, apoptosis, and cell death, were examined. Cells were cultured with HA and were analyzed by flow cytometry every 24 hours during a 168-hour period for proliferation and the presence of apoptotic and dead cells. These analyses demonstrated that HA inhibits U937 macrophage proliferation in a time-dependent manner. Through the first 72 hours, cells exhibited slowed proliferation. However, no evidence of cell division arrest or reduced cell viability was observed. Thereafter, HA continued to diminish proliferation, but induced apoptosis. This data is consistent with regulatory influences secondary to HA binding to CD44 and/or RHAMM cell surface receptors, both of which were shown to be expressed on U937 macrophages. This study demonstrates that a high concentration of high molecular weight HA greatly inhibits macrophage population growth by the dual actions of impeding cell proliferation and inducing apoptosis.

Clinical implications of growth factors in flexor tendon wound healing

Recent research has focused on the role of growth factors in flexor tendon wound healing. These basic science reports have described the identification and quantification of various growth factors in in vitro and in vivo models. Although these reports have begun to piece together the cascade of events involved in flexor tendon wound healing, the clinical relevance for the practicing hand surgeon is unclear. Growth factors are cell-secreted proteins that regulate cellular functions. These growth factors are involved in cell differentiation and growth, including the normal processes of development and tissue repair. Several growth factors recently have been identified as playing roles in tendon healing including vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), and transforming growth factor beta (TGF-beta). In addition, the transcription factor NF-kappaB has been implicated in the signaling pathways of these growth factors. The purpose of this article is to describe what is known about the molecular basis of flexor tendon wound healing, to review the most commonly studied growth factors, and to summarize likely clinical applications of these growth factors to flexor tendon repair.

Tissue engineering of flexor tendons

Despite technical advances in suture methods and rehabilitation protocols, challenges remain in the field of flexor tendon repair. This article reviews the state-of-the-art research in the tissue engineering of flexor tendons. These early published data will hopefully lay the foundation for molecular methods and materials that can be used to reconstruct tendons to restore normal form and function in the hand.