Non-Animal Stabilized Hyaluronic Acid

Intra-articular Hyaluronic Acid Treatments for Knee Osteoarthritis: A Systematic Review of Product Properties

INTRODUCTION

There are many intra-articular hyaluronic acid (IA-HA) products on the market that have known intrinsic differences in molecular size, source, and structure. The current review summarizes existing evidence describing and assessing these differences, while also identifying whether these differences have an impact on clinical outcomes.

METHODS

This systematic review summarized all literature that specifically addresses IA-HA product differences. Included studies summarized basic science and mechanism of action comparisons of IA-HA product differences, or systematic reviews that assess differences in clinical outcomes between IA-HA product differences.

RESULTS

A total of 20 investigations assessed basic science differences between IA-HA products, while 20 investigations provided assessments of the clinical outcome differences between IA-HA product characteristics. The published basic science literature provided a differentiation between low molecular weight (LMW) and high molecular weight (HMW) HA with regard to changes within the synovial fluid, driven by the interactions that these molecules have with receptors in the joint space. These differences in receptor interaction manifest within clinical outcomes, as meta-analyses comparing pain relief after IA-HA suggest that pain reduction is superior in patients who receive HMW HA as opposed to LMW HA.

CONCLUSION

This review highlights differences between IA-HA characteristics, and how important the molecular weight, derivation of the product, and structure are to variances in reported clinical outcomes to treat osteoarthritis (OA) of the knee. HMW IA-HAs have shown greater efficacy compared to the alternative of LMW products, while avian-derived and cross-linked products have potentially demonstrated an increase in inflammatory events over non-avian-derived, non-cross-linked HAs.

Connections between cohesion and properties that related to safety and effectiveness of the hyaluronic acid dermal fillers: A comparative study of the cohesive and non-cohesive gels

BACKGROUND

Although the importance of the cohesion of a hyaluronic acid (HA) filler has been recognized, the relationship between the cohesion and the other performance that related to safety and effectiveness, as well as the underlying mechanism is barely studied. Much efforts need to be made on this subject to provide guidance for clinical practice.

MATERIALS AND METHODS

Two types of the HA fillers (cohesive and particulate gels) were selected for the comparison of the cohesion and the other key physicochemical properties.

RESULTS

Hyalumatrix, with significantly higher cohesion, was homogeneously smooth and showed a linearly oriented morphology, whereas Matrifill and Restylane were particulate and showed obvious boundaries between particles. The high cohesion of Hyalumatrix is beneficial to the properties that related to safety and effectiveness, including recovery under shear stress, injectability, tissue integration and in vitro resistance to enzymolysis. The underlying reason was that the strong internal interactions of the cohesive gel protect the network structure from collapse and keep the gel as an intact whole when the gel was subjected to the stress. The homogeneously smooth morphology further improved the tissue compliance and injectability. The G' of Hyalumatrix is in the middle level of the commercially available HA fillers.

CONCLUSION

Hyalumatrix is a rare HA filler product to possess good cohesion and intermediate G' simultaneously. More clinical practice is needed to verify the connection between the cohesion of Hyalumatrix and the clinical performance.

The Rheology and Physicochemical Characteristics of Hyaluronic Acid Fillers: Their Clinical Implications

Hyaluronic acid (HA) fillers have become the most popular material for facial volume augmentation and wrinkle correction. Several filler brands are currently on the market all around the world and their features are extremely variable; for this reason, most users are unaware of their differences. The study of filler rheology has become a wellspring of knowledge, differentiating HA fillers, although these properties are not described thoroughly by the manufacturers. The authors of this review describe the more useful rheological properties that can help clinicians understand filler characteristics and the likely correlation of these features with clinical outcomes.

Design of an elastic porous injectable biomaterial for tissue regeneration and volume retention

Soft tissue reconstruction currently relies on two main approaches, one involving the implantation of external biomaterials and the second one exploiting surgical autologous tissue displacement. While both methods have different advantages and disadvantages, successful long-term solutions for soft tissue repair are still limited. Specifically, volume retention over time and local tissue regeneration are the main challenges in the field. In this study the performance of a recently developed elastic porous injectable (EPI) biomaterial based on crosslinked carboxymethylcellulose is analyzed. Nearly quantitative volumetric stability, with over 90% volume retention at 6 months, is observed, and the pore space of the material is effectively colonized with autologous fibrovascular tissue. A comparative analysis with hyaluronic acid and collagen-based clinical reference materials is also performed. Mechanical stability, evidenced by a low-strain elastic storage modulus (G') approaching 1kPa and a yield strain of several tens of percent, is required for volume retention in-vivo. Macroporosity, along with in-vivo persistence of at least several months, is instead needed for successful host tissue colonization. This study demonstrates the importance of understanding material design criteria and defines the biomaterial requirements for volume retention and tissue colonization in soft tissue regeneration. STATEMENT OF SIGNIFICANCE: We present the design of an elastic, porous, injectable (EPI) scaffold suspension capable of inducing a precisely defined, stable volume of autologous connective tissue in situ. It combines volume stability and vascularized tissue induction capacity known from bulk scaffolds with the ease of injection in shear yielding materials. By comparative study with a series of clinically established biomaterials including a wound healing matrix and dermal fillers, we establish design rules regarding rheological and compressive mechanical properties as well as degradation characteristics that rationally underpin the volume stability and tissue induction in a high-performance biomaterial. These design rules should allow to streamline the development of new colonizable injectables.

Combination of Hyaluronan and Lyophilized Progenitor Cell Derivatives: Stabilization of Functional Hydrogel Products for Therapeutic Management of Tendinous Tissue Disorders

Cultured progenitor cells and derivatives have been used in various homologous applications of cutaneous and musculoskeletal regenerative medicine. Active pharmaceutical ingredients (API) in the form of progenitor cell derivatives such as lysates and lyophilizates were shown to retain function in controlled cellular models of wound repair. On the other hand, hyaluronan-based hydrogels are widely used as functional vehicles in therapeutic products for tendon tissue disorders. The aim of this study was the experimental characterization of formulations containing progenitor tenocyte-derived APIs and hyaluronan, for the assessment of ingredient compatibility and stability in view of eventual therapeutic applications in tendinopathies. Lyophilized APIs were determined to contain relatively low quantities of proteins and growth factors, while being physicochemically stable and possessing significant intrinsic antioxidant properties. Physical and rheological quantifications of the combination formulas were performed after hydrogen peroxide challenge, outlining significantly improved evolutive viscoelasticity values in accelerated degradation settings. Thus, potent effects of physicochemical protection or stability enhancement of hyaluronan by the incorporated APIs were observed. Finally, combination formulas were found to be easily injectable into ex vivo tendon tissues, confirming their compatibility with further translational clinical approaches. Overall, this study provides the technical bases for the development of progenitor tenocyte derivative-based injectable therapeutic products or devices, to potentially be applied in tendinous tissue disorders.

Intraarticular Hyaluronic Acid Preparations for Knee Osteoarthritis: Are Some Better Than Others?

OBJECTIVE

This literature review summarizes evidence on the safety and efficacy of intraarticular hyaluronic acid (IAHA) preparations approved in the United States for the treatment of osteoarthritis of the knee.

DESIGN

A systematic literature search was performed in PubMed, Ovid MEDLINE, and SCOPUS databases. Only studies in which clinical outcomes of individual IAHA preparations alone could be assessed when compared to placebo, no treatment, other standard knee osteoarthritis treatments, and IAHA head-to-head studies were selected.

RESULTS

One hundred nine articles meeting our inclusion criteria were identified, including 59 randomized and 50 observational studies. Hylan G-F 20 has been the most extensively studied preparation, with consistent results confirming efficacy in placebo-controlled studies. Efficacy is also consistently reported for Supartz, Monovisc, and Euflexxa, but not for Hyalgan, Orthovisc, and Durolane. In the head-to-head trials, high-molecular-weight (MW) Hylan G-F 20 was consistently superior to low MW sodium hyaluronate preparations (Hyalgan, Supartz) up to 20 weeks, whereas one study reported that Durolane was noninferior to Supartz. Head-to-head trials comparing high versus medium MW preparations all used Hylan G-F 20 as the high MW preparation. Of the IAHA preparations with strong evidence of efficacy in placebo-controlled studies, Euflexxa was found to be noninferior to Hylan G-F 20. There are no direct comparisons to Monovisc. One additional IAHA preparation (ie, Synovial), which has not been assessed in placebo-controlled studies, was also noninferior to Hylan G-F 20.

CONCLUSION

IAHA efficacy varies widely across preparations. High-quality studies are required to assess and compare the safety and efficacy of IAHA preparations.

Molecular Weight of Hyaluronic Acid Has Major Influence on Its Efficacy and Safety for Viscosupplementation in Hip Osteoarthritis: A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to compare the efficacy and safety of intra-articular hyaluronic acid (HA) injection with different molecular weights (MWs) for treating hip osteoarthritis (OA).

METHODS

A systematic literature search for relevant studies was conducted in 3 electronic databases, including PubMed, BMJ Journals, and Cochrane Library, from inception to April 2020. Extracted outcomes included visual analogue scale (VAS) (1, 3, and 6 months), Lequesne index (3 and 6 months), and adverse effects. HAs were classified into low-molecular-weight (LMW), moderate-molecular-weight (MMW), high-molecular-weight (HMW), and ultra-high-molecular-weight (UHMW) groups. Meta-analysis was performed using Review Manager 5.3.

RESULTS

A total of 15 studies with 614 patients were included. Our meta-analysis showed that the HMW HA group had the best improvement in VAS and Lequesne index compared with other HA groups for all the follow-up visits. Moreover, the HMW group demonstrated significantly better improvement than the other groups in VAS at 6-month follow-up and in Lequesne index at 3- and 6-month follow-ups. Analysis for adverse effects revealed low rates of systemic adverse effects (≤0.6%) in all groups and similar rate of local adverse effects (around 10%) among the groups except for UHMW HA group (37.5%).

CONCLUSION

Among different MWs of HA for treating hip OA, HMW HA injection demonstrated the best efficacy for up to 6 months after treatment without increased risk of adverse effects. Further studies with more comprehensive data and a higher level of evidence are required to prove our results.

Long-Term Outcome Measures of Repeated Non-Animal Stabilized Hyaluronic Acid (Durolane) Injections in Osteoarthritis: A 6-Year Cohort Study with 623 Consecutive Patients

Purpose

To determine the duration of symptom relief following repeated administration of hyaluronic acid injections for osteoarthritis.

Patients and Methods

This was a 6-year observational study with 623 consecutive patients who had received hyaluronic acid injections. The primary outcome measure was the mean time between injections measured in days. Classical one-sample 2-sided t-tests, one-way analysis of variances and post-hoc analyses were performed to determine if there were statistically significant differences between age, gender, radiographic severity and the type of joints injected. All patients were invited to complete an online post-treatment experience and satisfaction survey.

Results

The analysis included 727 joints (mean Kellgren-Lawrence grade, 2.9 ± 0.8 (range 2–4)) in 623 patients (297 (47.7%) male; mean age at first injection, 57.8 ± 12.7 years (range 21.2–92.1)). Patients ranged from having 1–8 injections per joint. The mean time between injections in days was 466.8 ± 321.7 (2nd injection, 157 joints), 400.5 ± 164.7 (3rd injection, 58 joints), 378.2 ± 223.1 (4th injection, 27 joints), 405.3 ± 216.3 (5th injection, 7 joints), 268.4 ± 104.4 (6th injection, 5 joints), 289.8 ± 99.4 (7th injection, 4 joints), and 272.5 ± 33.2 (8th injection, 2 joints). Patients with grades 2 and 3 compared to grade 4 osteoarthritis experienced a longer time between injections (F (2, 154) = 3.53, p = 0.0316). No statistically significant differences were observed between age, gender, or joint groups. The survey included 233 participants (109 (46.8% male)). A total of 144 respondents (64.9%) recommended hyaluronic acid injections for osteoarthritis.

Conclusion

Pain relief from hyaluronic acid injections was sustained for on average 466.8 days post initial treatment. Patients who received subsequent 3rd, 4th, and 5th injections also experienced extended duration of benefit. Patients with grades 2 or 3 osteoarthritis are more likely to experience a longer duration of relief.

A versatile and robust analytical method for hyaluronan quantification in crosslinked products and complex matrices

Hyaluronic acid (HA), a naturally occurring biopolymer composed of repeating units of d-glucuronic acid and N-acetyl-glucosamine, is widely used as principal component of drugs, medical devices, nutraceuticals and cosmetics. Chemical modifications of HA or the presence of unmodified HA in complex matrices often brings common analytical techniques to fail its identification or quantification. In this work, a specific method for the quantification of HA and HA derivatives was developed and tested. After strong acid hydrolysis, polysaccharide depolymerization and N-acetylglucosamine deacetylation, quantitatively yielded glucosamine residues were derivatized using Fluorenylmethyloxycarbonyl chloride (FMOC), separated and quantitated by means of HPLC equipped with UV detection. The method was partially validated according to ICH Q2(R1) and successfully applied on different viscosupplements composed by modified HA or medical devices containing unmodified HA in complex matrices.

Anti‑inflammatory and anti‑catabolic effect of non‑animal stabilized hyaluronic acid and mesenchymal stem cell‑conditioned medium in an osteoarthritis coculture model

Previous clinical studies have reported the clinical effectiveness of non‑animal stabilized hyaluronic acid (NASHA) and adipose‑derived mesenchymal stromal/stem cells (MSC) in the treatment of knee osteoarthritis (OA). Unlike MSC secreted mediators, in vitro anti‑inflammatory effects of NASHA have not been evaluated. We aimed to evaluate and compare the anti‑inflammatory effect of NASHA and MSC conditioned medium (stem cell‑conditioned medium; SC‑CM), in an explant‑based coculture model of OA. Cartilage and synovial membrane from seven patients undergoing total knee arthroplasty were used to create a coculture system. Recombinant IL‑1β was added to the cocultures to induce inflammation. Four experimental groups were generated: i) Basal; ii) IL‑1β; iii) NASHA (NASHA + IL‑1β); and iv) SC‑CM (SC‑CM + IL‑1β). Glycosaminoglycans (GAG) released in the culture medium and of nitric oxide (NO) production were quantified. Gene expression in cartilage and synovium of IL‑1β, matrix metallopeptidase 13 (MMP13), ADAM metallopeptidase with thrombospondin type 1 motif 5 (ADAMTS5) and tissue inhibitor of metalloproteinases 1 (TIMP1) was measured by reverse transcription‑quantitative PCR. Media GAG concentration was decreased in cocultures with NASHA and SC‑CM (48 h, P<0.05; 72 h, P<0.01) compared with IL‑1β. Production of NO was significantly lower only in SC‑CM after 72 h (P<0.01). In cartilage, SC‑CM inhibited the expression of IL‑1β, MMP13 and ADAMTS5, while NASHA had this effect only in MMP13 and ADAMTS5. In synovium, SC‑CM decreased the expression level of MMP13 and ADAMTS5, while NASHA only decreased ADAMTS5 expression. Both NASHA and SC‑CM increased TIMP1 expression in cartilage and synovium. Treatments with NASHA and SC‑CM were shown to be a therapeutic option that may help counteract the catabolism produced by the inflammatory state in knee OA. The anti‑inflammatory mediators produced by MSC promote a lower expression of inflammatory targets in our study model.

Tunable methacrylated hyaluronic acid-based hydrogels as scaffolds for soft tissue engineering applications

Hyaluronic acid (HA)-based biomaterials have been explored for a number of applications in biomedical engineering, particularly as tissue regeneration scaffolds. Crosslinked forms of HA are more robust and provide tunable mechanical properties and degradation rates that are critical in regenerative medicine; however, crosslinking modalities reported in the literature vary and there are few comparisons of different scaffold properties for various crosslinking approaches. In this study, we offer direct comparison of two methacrylation techniques for HA (glycidyl methacrylate HA [GMHA] or methacrylic anhydride HA [MAHA]). The two methods for methacrylating HA provide degrees of methacrylation ranging from 2.4 to 86%, reflecting a wider range of properties than is possible using only a single methacrylation technique. We have also characterized mechanical properties for nine different tissues isolated from rat (ranging from lung at the softest to muscle at the stiffest) using indentation techniques and show that we can match the full range of mechanical properties (0.35-6.13 kPa) using either GMHA or MAHA. To illustrate utility for neural tissue engineering applications, functional hydrogels with adhesive proteins (either GMHA or MAHA base hydrogels with collagen I and laminin) were designed with effective moduli mechanically matched to rat sciatic nerve (2.47 ± 0.31 kPa). We demonstrated ability of these hydrogels to support three-dimensional axonal elongation from dorsal root ganglia cultures. Overall, we have shown that methacrylated HA provides a tunable platform with a wide range of properties for use in soft tissue engineering.

NASHA hyaluronic acid for the treatment of shoulder osteoarthritis: a prospective, single-arm clinical trial

Background: Osteoarthritis of the shoulder or glenohumeral joint is a painful condition that can be debilitating. Intra-articular injection with hyaluronic acid should be considered for patients not responding adequately to physical therapy or anti-inflammatory medication.

Methods: This was a single-arm, open-label, prospective study of a single intra-articular injection of NASHA (non-animal hyaluronic acid) in patients with symptomatic glenohumeral osteoarthritis. Patients were followed up for 26 weeks post-treatment, during which time rescue medication with acetaminophen was permissible. The study objective was to demonstrate that a single injection of NASHA is well tolerated with an over-6-month 25% reduction in shoulder pain on movement, assessed using a 100-mm visual analog scale.

Results: Forty-one patients were enrolled, all of whom received study treatment. The mean decrease in shoulder pain on movement score over the 6-month study period was −20.1 mm (95% CI: −25.2, −15.0 mm), corresponding to a mean reduction of 29.5% (22.0, 37.0%). Statistically significant improvements were also observed in shoulder pain at night and patient global assessment. There was no clear change over time in the percentage of patients using rescue medication and mean weekly doses were below 3500 mg. Seventeen patients (41.5%) experienced adverse events, all of which were mild or moderate. Two adverse events (both shoulder pain) were deemed related to study treatment.

Conclusion: This study provides preliminary evidence that a single injection of NASHA may be efficacious over 6 months and well tolerated in patients with symptomatic glenohumeral osteoarthritis. Larger studies are needed for confirmation.

A Synthetic Bottle-brush Polyelectrolyte Reduces Friction and Wear of Intact and Previously Worn Cartilage

A poly(7-oxanorbornene-2-carboxylate) polymer containing pendent triethyleneglycol (TEG) chains of 2.8 MDa ("2.8M TEG") was synthesized and evaluated for long-term lubrication and wear reduction of ex vivo bovine cartilage as well as for synovitis in rats and dogs after intra-articular administration. Bovine cartilage surfaces were tested under torsional friction for 10,080 rotations while immersed in either saline, bovine synovial fluid (BSF), or 2.8M TEG. For each solution, coefficient of friction (μ), changes in surface roughness, and lost cartilage glycosaminoglycan were compared. To directly compare 2.8M TEG and BSF, additional samples were tested sequentially in BSF, BSF, 2.8M TEG, and then BSF. Finally, another set of samples were tested twice in saline to induce surface roughness and then tested in BSF, Synvisc, or 2.8M TEG to determine each treatment's effect on worn cartilage. Next, male Lewis rats were injected in one knee with 2.8M TEG or saline and evaluated for effects on gait, and female beagles were injected with either 2.8M TEG or saline in one knee, and their synovial tissues analyzed for inflammation by H&E staining. Treatment with 2.8M TEG lowers μ, lessens surface roughness, and minimizes glycosaminoglycan loss compared to saline. The 2.8M TEG also reduces μ compared to BSF in pairwise testing and on worn cartilage surfaces. Injection of 2.8M TEG in rat or beagle knees gives comparable effects to treatment with saline, and does not cause significant synovitis.

Nonanimal Hyaluronic Acid for the Treatment of Ankle Osteoarthritis: AProspective, Single-Arm Cohort Study

Ankle osteoarthritis (OA) can cause disabling symptoms, and some patients prefer to be treated with minimally invasive procedures. Nonanimal hyaluronic acid (NASHA) is a cross-linked hyaluronic acid product that has a prolonged intra-articular residence time. The authors report the first study of NASHA for the treatment of ankle OA. Thirty-seven patients with Kellgren-Lawrence grade II or III ankle OA received an intra-articular injection of NASHA (1 mL). Outcomes included visual analogue scale (VAS) scores for pain and disability. At baseline, the mean VAS pain score was 50.1 ± 14.5mm. During the 26-week follow-up period, the least squares (LS) mean change from baseline in the ankle OA VAS pain score was -20.5mm (95% confidence interval [CI] -25.5 to -15.6 mm), an LS mean percentage reduction of 40.0% (95% CI 30.2% to 49.9%). The LS mean change from baseline in the VAS disability score during 26 weeks was -19.2mm (95% CI -24.8 to -13.6 mm), a percentage reduction of 34% (95% CI 22.3% to 45.7%). Five participants experienced a total of 7 adverse events considered to be related to study treatment (injection site pain, n = 3; injection site joint pain, n = 3; plantar fasciitis, n = 1). This study shows promise for viscosupplementation with NASHA in the treatment of ankle OA. A single injection was associated with clinically meaningful reductions in pain and disability during a 26-week period and, in general, was well tolerated.

Anti-bacterial materials based on hyaluronic acid: Selection of research methodology and analysis of their anti-bacterial properties

In the frame of the presented research, highly-porous structures made of hyaluronic acid modified with bioactive compounds were prepared. The method of microbiological testing of hygroscopic materials has been elaborated by verification of the JIS L 1902:2002 and ASTM E2149-13a test methods. The research has shown that the method developed in accordance with ASTM E2149-13a is suitable for testing the activity of hyaluronic acid samples against bacteria. E. coli and S. aureus. In the case of E. coli it is preferred to use as a medium the phosphoric buffer and for S. aureus NaCl solution from NB. By analysing the results of the antibacterial properties, it is important to note that the introduction of a small amount of zinc and zinc oxide in the matrix from the hyaluronic acid (in the amount of 3% by weight of the polymer) makes it possible to obtain a material with a strong activity against the bacterial strains. It enables to use this type of material as a treatment for hard-to-treat, infected wounds. On the other hand, using a relatively small dose of the cephalosporin antibiotic did not result in high levels of activity against the bacteria Gram "+" and Gram "-".

Systematic clinical evidence review of NASHA (Durolane hyaluronic acid) for the treatment of knee osteoarthritis

Background

Pain and limitations in joint mobility associated with knee osteoarthritis (OA) are clinically challenging to manage, and advanced progression of disease can often lead to total knee arthroplasty. Intra-articular injection of hyaluronic acid (HA), also referred to as viscosupplementation, is a non-surgical treatment approach for OA, the effectiveness of which may depend on the HA composition, and the length of time over which it resides in the joint. One of the available options for such therapies includes NASHA (Durolane HA), a non-animal, biofermentation-derived product, which is manufactured using a process that stabilizes the HA molecules to slow down their rate of degradation and produce a unique formulation with a terminal half-life of ~1 month. The objectives of the current review were to assess, in patients with OA of the knee, the efficacy and safety of intra-articular treatment with NASHA relative to control (saline) injections, other HA products, and other injectables (corticosteroids, platelet-rich plasma, mesenchymal stem cells).

Methods

This systematic evidence review examines patient outcomes following NASHA treatment as described in published data from studies conducted in subjects with knee OA. A Preferred Reporting Items for Systematic Reviews and Meta-analyses-compliant literature search strategy yielded 11 eligible clinical studies with a variety of comparator arms. Outcomes assessed at various time points following intra-articular treatment included measures of pain, function, quality of life, and incidence of treatment-related adverse events (AEs).

Results

The available evidence reported for the clinical studies assessed demonstrates sustained and effective relief of knee OA symptoms following a single injection of NASHA. In addition, an excellent biocompatibility profile is observed for NASHA as an intra-articular therapy for OA, as reflected by the low rate of AEs associated with treatment.

Conclusion

Treatment with NASHA is an effective and safe single-injection procedure, which can be beneficial in the clinical management of knee OA.

Key importance of compression properties in the biophysical characteristics of hyaluronic acid soft-tissue fillers

Hyaluronic acid (HA) soft-tissue fillers are the most popular degradable injectable products used for correcting skin depressions and restoring facial volume loss. From a rheological perspective, HA fillers are commonly characterised through their viscoelastic properties under shear-stress. However, despite the continuous mechanical pressure that the skin applies on the fillers, compression properties in static and dynamic modes are rarely considered. In this article, three different rheological tests (shear-stress test and compression tests in static and dynamic mode) were carried out on nine CE-marked cross-linked HA fillers. Corresponding shear-stress (G', tanδ) and compression (E', tanδc, normal force FN) parameters were measured. We show here that the tested products behave differently under shear-stress and under compression even though they are used for the same indications. G' showed the expected influence on the tissue volumising capacity, and the same influence was also observed for the compression parameters E'. In conclusion, HA soft-tissue fillers exhibit widely different biophysical characteristics and many variables contribute to their overall performance. The elastic modulus G' is not the only critical parameter to consider amongst the rheological properties: the compression parameters E' and FN also provide key information, which should be taken into account for a better prediction of clinical outcomes, especially for predicting the volumising capacity and probably the ability to stimulate collagen production by fibroblasts.

Intraosseous Pseudotumor After Knee Viscosupplementation: A Case Report

CASE

A sixty-eight-year-old woman with osteoarthritis in the right knee who had received a single injection of a commercial hyaluronic acid preparation presented with an intraosseous mass that had not appeared in previous imaging studies. Open biopsy and curettage was performed, and a reactive pseudotumor related to viscosupplementation was diagnosed. At the last follow-up fourteen months after surgery, the patient had experienced no recurrence of the lesion.

CONCLUSION

Viscosupplementation is considered a conservative treatment option for early-stage knee osteoarthritis. To the best of our knowledge, this complication, namely an intraosseous mass, has not been described previously in the literature.

A randomized saline-controlled trial of NASHA hyaluronic acid for knee osteoarthritis

OBJECTIVE

NASHA hyaluronic acid is administered as a single intra-articular injection to treat the symptoms of osteoarthritis (OA). In a previous trial, post-hoc analysis indicated that NASHA provides significantly greater pain relief than saline in patients with OA confined to the study knee. We aimed to evaluate the safety and efficacy of NASHA in patients with unilateral knee OA.

RESEARCH DESIGN AND METHODS

This was a randomized, double-blind, saline-controlled trial. All patients had knee OA confirmed by American College of Rheumatology criteria and a WOMAC pain score of 7-17 in the study knee, but no pain in the previous 3 months in the non-study knee. Treatment comprised a single intra-articular injection of NASHA or saline control. The follow-up period was 6 weeks.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT01806207.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was the responder rate, defined as the percentage of patients with ≥40% improvement from baseline in WOMAC pain score and an absolute improvement of ≥5 points.

RESULTS

A total of 218 patients received study treatment (NASHA: 108, saline: 110). In the main intention-to-treat (ITT) analysis, no statistically significant difference in responder rate was found between the two groups at 6 weeks (NASHA: 30.6%; saline: 26.4%). A post-hoc subgroup analysis of patients without clinical effusion in the study knee at baseline showed a significantly higher 6 week responder rate with NASHA than with saline: 40.6% versus 19.7% (p = 0.0084). A total of 68 adverse events were reported among 44 patients in the NASHA group, compared with 69 adverse events among 44 patients in the saline group. The main weakness of the study was the short, 6 week follow-up duration. In addition, image guidance was not used to ensure injection as intended into the intra-articular space.

CONCLUSIONS

Single-injection NASHA was well tolerated and, although there was no significant benefit versus saline control in the primary analysis, post-hoc analysis showed a statistically significant improvement in pain relief at 6 weeks among patients without clinical effusion at baseline.

NASHA hyaluronic acid vs. methylprednisolone for knee osteoarthritis: a prospective, multi-centre, randomized, non-inferiority trial

OBJECTIVE

To compare NASHA hyaluronic acid gel as single-injection intra-articular (IA) treatment for knee osteoarthritis (OA) against methylprednisolone acetate (MPA).

DESIGN

This was a prospective, multi-centre, randomized, active-controlled, double-blind, non-inferiority clinical trial. A unique, open-label extension phase (OLE) was undertaken to answer further important clinical questions. Subjects with painful unilateral knee OA were treated and followed for 26 weeks (blinded phase). All patients attending the clinic at 26 weeks were offered NASHA treatment, with a subsequent 26-week follow-up period (extension phase). The primary objective was to show non-inferiority of NASHA vs MPA in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain responder rate (percentage of patients with ≥40% improvement from baseline in WOMAC pain score and an absolute improvement of ≥5 points) at 12 weeks.

RESULTS

In total, 442 participants were enrolled. The primary objective was met, with NASHA producing a non-inferior response rate vs MPA at 12 weeks (NASHA: 44.6%; MPA: 46.2%; difference [95% CI]: 1.6% [-11.2%; +7.9%]). Effect size for WOMAC pain, physical function and stiffness scores favoured NASHA over MPA from 12 to 26 weeks. In response to NASHA treatment at 26 weeks, sustained improvements were seen in WOMAC outcomes irrespective of initial treatment. No serious device-related adverse events (AEs) were reported.

CONCLUSIONS

This study shows that single-injection NASHA was well tolerated and non-inferior to MPA at 12 weeks. The benefit of NASHA was maintained to 26 weeks while that of MPA declined. An injection of NASHA at 26 weeks conferred long-term improvements without increased sensitivity or risk of complications. STUDY IDENTIFIER: NCT01209364 (www.clinicaltrials.gov).

Solid freeform fabrication of designer scaffolds of hyaluronic acid for nerve tissue engineering

The field of tissue engineering and regenerative medicine will tremendously benefit from the development of three dimensional scaffolds with defined micro- and macro-architecture that replicate the geometry and chemical composition of native tissues. The current report describes a freeform fabrication technique that permits the development of nerve regeneration scaffolds with precisely engineered architecture that mimics that of native nerve, using the native extracellular matrix component hyaluronic acid (HA). To demonstrate the flexibility of the fabrication system, scaffolds exhibiting different geometries with varying pore shapes, sizes and controlled degradability were fabricated in a layer-by-layer fashion. To promote cell adhesion, scaffolds were covalently functionalized with laminin. This approach offers tremendous spatio-temporal flexibility to create architecturally complex structures such as scaffolds with branched tubes to mimic branched nerves at a plexus. We further demonstrate the ability to create bidirectional gradients within the microfabricated nerve conduits. We believe that combining the biological properties of HA with precise three dimensional micro-architecture could offer a useful platform for the development of a wide range of bioartificial organs.

Intra-articular Duration of Durolane™ after Single Injection into the Rabbit Knee

OBJECTIVE

The aim of the present study was to investigate the intra-articular duration of Durolane™ in a rabbit model to allow comparison between Durolane™ residence time and data reported for other hyaluronic acid products as well as native hyaluronic acid.

DESIGN

(14)C-labeled Durolane™ was manufactured by labeling the cross-linker used for stabilization. A single injection of approximately 0.3 mL (14)C-labeled Durolane™ was administered intra-articularly in both knee joints of male New Zealand White rabbits. At days 1, 2, 3, 7, 28, 60, 96, and 120 after injection, the knee joints of 4 animals were collected, and the radioactivity of the remaining gel was measured. The obtained data were fitted by exponential models to calculate the half-life of the gel. Two additional rabbits were used for histology of the joint 127 days after the injection.

RESULTS

The elimination of (14)C-labeled Durolane™ followed first-order kinetics with an apparent half-life of approximately 32 days. Histology showed no morphological changes in the knee joints.

CONCLUSIONS

This study shows that Durolane™ has a half-life of 32 days in the rabbit knee joint, which is much longer compared to literature data on hyaluronic acid and other modified hyaluronic acid products.

Therapeutic arthrography and bursography

Arthrography and bursography as therapeutic venues have found their place in the musculoskeletal procedure armamentarium. Therapeutic arthrography not only rules in and rules out the origin of pain but can provide 6 to 9 months of pain relief in diseased joints. Therapeutic arthrography allows injections of anesthetic, corticosteroid, or alternatively hyaluronic acid to be delivered accurately to the source of pain. Corticosteroids have a long history of use in osteoarthritis. Alternative therapy with hyaluronic acid is anew procedure. This article reviews the technique of arthrography in different joints and bursae and discusses the pros and cons of the use of corticosteroids versus viscosupplementation in therapeutic arthrography.