A risk-benefit assessment of injections of hyaluronan and its derivatives in the treatment of osteoarthritis of the knee

Management strategies for osteoarthritis, ankylosing spondylitis, and gouty arthritis

Rheumatic diseases are among the most frequent causes of pain and disability. Effective management of rheumatic diseases including osteoarthritis (OA), ankylosing spondylitis (AS), and gouty arthritis requires an understanding of the underlying disease mechanisms.Symptoms of OA result from both mechanical factors and elements of inflammation. Current management strategies target both of these factors and generally consist of nonpharmacologic and pharmacologic interventions, including use of nonspecific nonsteroidal antiinflammatory drugs (NSAIDs) and cyclooxygenase-2-specific inhibitors (coxibs), which have analgesic and antiinflammatory properties. Other approaches include intraarticular hyaluronate and the use of alternative therapies under investigation such as acupuncture or glucosamine.Disease mechanisms in AS involve enthesitis, an inflammation at the site of insertion of ligaments, tendons, or joint capsules to bone. Posture and exercise are important nonpharmacologic strategies that may be made easier with the use of NSAIDs or coxibs. Recently developed therapies, including tumor necrosis factor inhibitors, target the underlying disease mechanisms and have demonstrated dramatic symptomatic effects. Disease-modifying effects still need to be established.In gout, hyperuricemia leads to crystal-induced inflammation in some patients. Etoricoxib, one of the newer coxibs, has shown promise in treating acute gout, with efficacy similar to indomethacin, the current standard NSAID often used in these patients. Oral or intraarticular steroids can also be considered. For chronic care uricosurics can be beneficial if renal function is normal and excretion is not excessive, but allopurinol is used most often. Nonpharmacologic modalities, such as rest and cold applications, are useful for acute episodes, and lifestyle modification in the form of diet can also play a role in chronic disease management.

Racial differences in symptom management approaches among persons with radiographic knee osteoarthritis

Background

The extent to which racial differences exist in use of treatments for osteoarthritis (OA) is debatable. The purpose of this study was to describe the differences between African Americans (AA) and Caucasian Americans (CA) in using treatment approaches to manage symptoms among individuals with radiographic-confirmed knee OA.

Methods

A cross-sectional study was conducted. Using data from the Osteoarthritis Initiative, we identified 508 AA and 2,075 CA with radiographic tibiofemoral OA in at least one knee. Trained interviewers asked questions relating to current OA treatments including seven CAM therapy categories—alternative medical systems, mind-body interventions, manipulation and body-based methods, energy therapies, and three types of biologically based therapies, as well as conventional medications. We categorized participants as: conventional medication only users, CAM only users, users of both and users of neither. Multinomial logistic regression models adjusting for sociodemographics and clinical/functional factors provided estimates of the association between race and treatment use.

Results

Overall, 16.5% of AA and 24.2% of CA exclusively used CAM to treat OA, 25.0% of AA and 23.8% of CA used CAM in conjunction with conventional medications, and 24.8% of AA and 14.6% of CA exclusively used conventional medications. After control for sociodemographic and clinical factors, AA were less likely than CA to use CAM therapies alone (adjusted odds ratio (OR) of using CAM alone relative to no CAM or conventional treatments: 0.68, 95% confidence interval (CI): 0.48–0.96) or with conventional medications (adjusted OR relative to no CAM or conventional treatments: 0.59, 95%CI: 0.42–0.83). However, no differences in use of conventional medications alone were observed after adjustment of covariates.

Conclusion

CAM use is common among people with knee OA, but is less likely to be used by AA relative to CA. For effective CAM therapies, targeted outreach to underserved populations including education about benefits of various CAM treatments and providing accessible care may attenuate observed disparities in effective CAM use by race.

Rate of adverse reactions to more than 1 series of viscosupplementation

Viscosupplementation, hyaluronic acid treatment, is an ancillary method for treating patients with symptomatic stage I or II osteoarthritis. Previous studies reported that local reactions occurred more frequently in patients receiving >1 course of treatment compared with patients receiving their first course of treatment. One (2%) of 42 first series patients and 4 (21%) of 19 of repeated series patients had adverse reactions severe enough to seek unscheduled care.This study was performed to determine whether patients receiving >1 series of viscosupplementation had an increased adverse reaction rate. A retrospective chart review was performed on all patients who received >1 series of viscosupplementation during the study. A local adverse reaction was defined as acute swelling and pain in the knee, with no injury or trauma within 72 hours after hyaluronic acid injection.Twenty-eight knees received >1 series of viscosupplementation. The adverse reaction rate to second series injections was 1.28% (3.57% of knees). The adverse reaction rate to ≥3 series was 0.9% (6.67% of knees). This adverse reaction rate was significantly less than the 21% reported in previous studies for multiple series injections (z=-1.90; P<.05) and is not significantly different than the 2% rate of adverse reactions reported for first series injections. No significant difference existed in the adverse reaction rates between 2 series and ≥3 series of viscosupplementation.The current study suggests that the rate of adverse reaction was low at 1.28% of second series viscosupplementation.

Effect of a dietary supplement containing glucosamine hydrochloride, chondroitin sulfate and quercetin glycosides on symptomatic knee osteoarthritis: a randomized, double-blind, placebo-controlled study

BACKGROUND

Oral glucosamine and chondroitin sulfate, alone and in combination, have been used worldwide for the treatment of osteoarthritis (OA), but their efficacy is controversial. This clinical study was aimed at investigating the potential of a dietary supplement containing glucosamine and chondroitin sulfate in combination with derivatives of quercetin, a naturally occurring flavonoid, (GCQ supplement) for knee OA care.

RESULTS

A randomized, double-blind, placebo-controlled study was conducted in 40 Japanese subjects with symptomatic knee OA. Subjects were randomly assigned to GCQ supplement (1200 mg glucosamine hydrochloride, 60 mg chondroitin sulfate and 45 mg quercetin glycosides per day) or placebo and the treatment and follow-up were continued for 16 weeks. The results of symptomatic efficacy assessment based on Japanese Orthopaedic Association criteria showed that scores for two of the four symptom/function subscales, as well as the aggregate scores, were significantly improved at week 16 or earlier in the GCQ group compared to the placebo group. Moreover, analyses of cartilage metabolism biomarkers showed a trend of improvement in type II collagen synthesis/degradation balance in the GCQ group during follow-up.

CONCLUSION

GCQ supplement was thought to be more effective than placebo in decreasing the intensity of knee OA-associated clinical symptoms.

Intra-articular injection of hyaluronic acid is not superior to saline solution injection for ankle arthritis: a randomized, double-blind, placebo-controlled study

BACKGROUND

Intra-articular injections of hyaluronic acid are potentially useful to treat ankle osteoarthritis, yet their effectiveness has not been proven. Both single and multiple-dose treatments for ankle arthritis with use of various hyaluronic acid products have been recommended, but few high-quality studies have been published. The aim of this study was to compare the effectiveness of a single intra-articular injection of hyaluronic acid with a single intra-articular injection of normal saline solution (placebo) for osteoarthritis of the ankle.

METHODS

Sixty-four patients with ankle osteoarthritis who met all study criteria were randomly assigned to a single intra-articular injection of 2.5 mL of low-molecular-weight, non-cross-linked hyaluronic acid or a single intra-articular injection of 2.5 mL of normal saline solution. The primary outcome measure was the change from baseline in the American Orthopaedic Foot & Ankle Society (AOFAS) clinical rating score at the six-week and twelve-week follow-up examination. Secondary outcome measures included the Ankle Osteoarthritis Scale score and patient-reported pain with use of a visual analog pain scale.

RESULTS

Of the sixty-four patients randomized and treated, eight patients withdrew, leaving fifty-six patients who completed the entire study. There was one mild adverse event (1.6%) among the sixty-four patients. At six weeks and twelve weeks, the mean AOFAS scores in the hyaluronic acid group had improved from baseline by 4.9 and 4.9 points, respectively, whereas the mean AOFAS scores in the placebo group initially worsened by 0.4 point at six weeks and then improved by 5.4 points at twelve weeks. While the change at twelve weeks from baseline was substantial for both groups, the between-group differences were not significant.

CONCLUSIONS

We found that a single intra-articular injection of low-molecular-weight, non-cross-linked hyaluronic acid is not demonstrably superior to a single intra-articular injection of saline solution for the treatment of osteoarthritis of the ankle.

Effect of a glucosamine-based combination supplement containing chondroitin sulfate and antioxidant micronutrients in subjects with symptomatic knee osteoarthritis: A pilot study

In the present study, we aimed to investigate the potential effect of a glucosamine (1,200 mg/day)-based dietary supplement combined with chondroitin sulfate and three antioxidant micronutrients, namely methylsulfonylmethane, guava leaf extract, and vitamin D (test supplement) on osteoarthritis (OA) of the knee. A 16-week, randomized, double-blinded, placebo-controlled trial was conducted involving 32 subjects with symptomatic knee OA. Clinical outcomes were measured using the Japanese Knee Osteoarthritis Measure (JKOM) for symptoms and a study diary-based visual analog scale (diary VAS) for pain at baseline and at weeks 4, 8, 12 and 16 during the 16-week intervention period. Furthermore, biomarkers for cartilage type II collagen degradation (C2C) and synovitis hyaluronan (HA) were measured. As compared with the baseline, the JKOM pain subscale was significantly improved at all of the four assessment time points in the test group, but was not at any time point in the placebo group. On the other hand, all of the four symptom subscales and the aggregated total symptoms were significantly improved in the two groups at one or more time points. However, all of these clinical improvements were greater in extent in the test group than in the placebo group, and there were significant differences between groups in the magnitude of changes from baseline for one subscale 'general activities' and the aggregated total symptoms at week 8 (P<0.05). The results of efficacy assessments with the diary VAS showed that all of the three pain subscales were significantly improved only in the test group at almost all the time points. Moreover, serum levels of C2C and HA were decreased by 10 and 25%, respectively, at week 16 in the test group, albeit not statistically significant, without any detectable changes in the placebo group. In conclusion, although the results obtained in this study were not conclusive, the tested glucosamine-based combination supplement is likely to have a beneficial effect on pain and other symptoms associated with knee OA.

Viscosupplementation in the management of ankle osteoarthritis: a review

INTRODUCTION

Osteoarthritis (OA) is a disease of synovial joints and is the most common cause of chronic pain. Viscosupplementation (VS) with hyaluronic acid (HA) is largely used for knee osteoarthritis therapy but the evidence for its usefulness in ankle osteoarthritis is limited. The objective of this review is to assess the efficacy of viscosupplementation treatment of ankle osteoarthritis in the current literature.

METHODS

The following databases were searched: Medline (period 2006-2008), Database of Abstract on Reviews and Effectiveness and Cochrane Database of Systematic Reviews. Reference lists of relevant articles were controlled for additional references. The search terms Review, Viscosupplementation (VS), Osteoarthritis (OA), Hyaluronic acid (HA), Hyaluronan, Sodium hyaluronate, Ankle OA, Ankle joint were used to identify all studies relating to the use of VS therapy for the ankle OA. Methodological quality of included studies was assessed by assigning level of evidence as previously defined by the Centre for Evidence Based Medicine (CEBM).

RESULT

Seven articles concerning the efficacy of a total of 275 patients undergoing VS treatment for ankle OA were included. One European study, one Taiwanese study, one Italian study, one Turkish study and three American studies with level of evidence ranging from I to IV evaluated the following products: Hyalgan, Synvisc, Supartz, Adant.

CONCLUSION

Viscosupplementation is used widely in knee OA and is included in the professional guidelines for treatment of the disease in this joint. The potential for treating osteoarthritis of the ankle joint by viscosupplementation has been suggested in the literature, however, no dosing studies have been published to date, and dosing in the ankle joint remains an area for discussion. Viscosupplementation could potentially provide an useful alternative in treating such patients with painful ankle OA.

Intra-articular sodium hyaluronate injections in the osteoarthritic ankle joint: effects, safety and dose dependency

BACKGROUND

To determine the efficacy, safety and dose dependency of intra-articular Orthovisc(®) hyaluronic acid injections in the ankle.

METHODS

A prospective single blinded study in patients with symptomatic ankle-osteoarthritis. Patients were randomly allocated to 1, 2, 3 ml, or 3 weekly injections of 1 ml (3 × 1 ml). Primary outcome was 'pain during walking' at 15 weeks measured on a 100mm VAS.

RESULTS

Twenty-six patients (ITT) participated. The 3 × 1 ml dose group showed statistically significant decreases at week 7 for 'pain during walking' and 'pain at rest' (p=0.046). At week 15 decreases were significant for 'pain at rest' (p=0.046). There was no significant decrease of VAS-scores in any of the single dose groups. Seven patients experienced temporary local swelling and increased pain in the injected ankle.

CONCLUSIONS

Orthovisc(®) viscosupplementation in the ankle joint is effective and well tolerated. The 3 × 1 ml dose regimen shows the best results.

Evaluation of the effects of a supplementary diet containing chicken comb extract on symptoms and cartilage metabolism in patients with knee osteoarthritis

We aimed to investigate whether a supplementary diet containing chicken comb extract (CCE) rich in hyaluronic acid (HA) has an effect on pain and other symptoms, as well as cartilage type II collagen (CII) metabolism in patients with knee osteoarthritis (OA). A randomized double-blind placebo-controlled study was conducted in 43 subjects with knee OA (Kellgren/Lawrence grade, mainly 1-2) comprising 22 patients receiving concurrent exercise therapy (ET) and 21 without ET (referred as ET-receivers and ET-unreceivers, respectively). Subjects were randomized to a CCE-containing diet (active diet) group administered a dose of 1,800 mg/day (containing 630 mg of CCE and approximately 60 mg of HA) and a placebo group, and the intervention was continued for 16 weeks. Symptomatic efficacy was evaluated based on the Japanese Orthopaedic Association clinical trials response criteria (JOA response criteria) and Visual analog scales (VAS) before (baseline) and during the intervention. To further examine its effect on CII metabolism, the levels of two degradation biomarkers (CTX-II and C2C) and one synthesis biomarker (CPII) were measured using urine or serum samples. Nineteen subjects (10 ET-receivers and 9 ET-unreceivers) in the active diet group and 21 subjects (10 ET-receivers and 11 ET-unreceivers) in the placebo group were finally included in the study. Compared to the baseline, subscale scores of the JOA response criteria, i.e., 'pain/walking function', 'pain/step-up and -down function' and 'aggregate total symptoms' were more intensely improved in the active diet group than in the placebo group. Moreover, subgroup analyses of ET-receivers and ET-unreceivers indicated that significant improvements were restricted to ET-receivers of the active diet group. Furthermore, VAS assessment indicated that the 'pain on pressing' subscale was significantly improved in ET-receivers of the active diet group. In addition, analysis of CII biomarkers revealed that serum C2C and CPII levels, but not the urinary CTX-II level, were increased in the active diet group. Notably, both urinary CTX-II/serum CPII and serum C2C/serum CPII ratios were reduced in the active diet group (particularly ET-unreceivers), suggesting that CII synthesis was relatively increased compared to CII degradation in the active diet group. Finally, no diet-related side effects were observed. The CCE-containing diet is likely to be effective in relieving symptoms in patients with knee OA. In addition, it has the potential to improve the balance of CII degradation/synthesis in knee OA.

Cross-linked hyaluronan gel reduces the acute rectal toxicity of radiotherapy for prostate cancer

PURPOSE

To prospectively analyze whether cross-linked hyaluronan gel reduces the mean rectal dose and acute rectal toxicity of radiotherapy for prostate cancer.

METHODS AND MATERIALS

Between September 2008 and March 2009, we transperitoneally injected 9 mL of cross-linked hyaluronan gel (Hylaform; Genzyme Corporation, Cambridge, MA) into the anterior perirectal fat of 10 early-stage prostate cancer patients to increase the separation between the prostate and rectum by 8 to 18 mm at the start of radiotherapy. Patients then underwent high-dose rate brachytherapy to 2,200 cGy followed by intensity-modulated radiation therapy to 5,040 cGy. We assessed acute rectal toxicity using the National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 grading scheme.

RESULTS

Median follow-up was 3 months. The anteroposterior dimensions of Hylaform at the start and end of radiotherapy were 13 +/- 3mm (mean +/- SD) and 10 +/- 4mm, respectively. At the start of intensity-modulated radiation therapy, daily mean rectal doses were 73 +/- 13 cGy with Hylaform vs. 106 +/- 20 cGy without Hylaform (p = 0.005). There was a 0% incidence of National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 Grade 1, 2, or 3 acute diarrhea in 10 patients who received Hylaform vs. a 29.7% incidence (n = 71) in 239 historical controls who did not receive Hylaform (p = 0.04).

CONCLUSIONS

By increasing the separation between the prostate and rectum, Hylaform decreased the mean rectal dose. This led to a significant reduction in the acute rectal toxicity of radiotherapy for prostate cancer.

Hylan G-F 20 single-injection formulation

Hylan G-F 20, a cross-linked hyaluronic acid derivative, is an elastoviscous, high-molecular-weight (average 6000 kDa) fluid with rheological properties similar to those of knee synovial fluid of healthy young individuals. In a 26-week, randomized, double-blind, multicentre study in patients with symptomatic primary osteoarthritis of the knee (n = 253), one intra-articular injection of hylan G-F 20 (single-injection formulation) into the target knee significantly relieved pain (as measured by the Western Ontario and McMaster Universities Osteoarthritis Index pain [WOMAC A] subscale), including pain while walking on a flat surface (as assessed by the WOMAC A1 subscore), compared with placebo. Observer-reported disease status and patient-reported health status were also significantly improved in hylan G-F 20-treated patients compared with placebo-treated patients. A single intra-articular injection of hylan G-F 20 was generally well tolerated, with an adverse event profile similar to that of placebo. Repeat administration of hylan G-F 20 after 6 months had a similar tolerability profile to that of the initial injection. However, no patient who developed a target-knee adverse event after their first injection experienced such an event following their second injection.

Synthesis and optimization of hyaluronic acid-methotrexate conjugates to maximize benefit in the treatment of osteoarthritis

We previously reported that a conjugate of hyaluronic acid (HA) and methotrexate (MTX) could be a prototype for future osteoarthritis drugs having the efficacy of the two clinically validated agents but with a reduced risk of the systemic side effects of MTX by using HA as the drug delivery carrier. To identify a clinical candidate, we attempted optimization of a lead, conjugate 1. Initially, in fragmentation experiments with cathepsins, we optimized the peptide part of HA-MTX conjugates to be simpler and more susceptible to enzymatic cleavage. Then we optimized the peptide, the linker, the molecular weight, and the binding ratio of the MTX of the conjugates to inhibit proliferation of human fibroblast-like synoviocytes in vitro and knee swelling in rat antigen-induced monoarthritis in vivo. Consequently, we found conjugate 30 (DK226) to be a candidate drug for the treatment of osteoarthritis.

Rheologic behavior of osteoarthritic synovial fluid after addition of hyaluronic acid: a pilot study

Viscosupplementation is a symptomatic treatment of osteoarthritis (OA) intended to restore rheologic homeostasis of the synovial fluid by injecting hyaluronic acid intraarticularly. Despite the long history of this therapy, little is known about its mechanisms of action and differences between commercial preparations. We investigated the rheologic behavior of OA synovial fluid with time, when stored at 4 degrees C, before and after the addition of two hyaluronic acid commercial preparations (linear and cross-linked). Thirteen OA synovial fluids were stored at 4 degrees C and assayed using steric exclusion chromatography, which allows hyaluronic acid to be separated from the remaining pool of proteins and its molecular weight and concentration to be determined without any pretreatment and calibration. The synovial fluid rheology also was studied in vitro, before and after addition of two viscosupplements, over 6 weeks. The non-Newtonian behavior of synovial fluid throughout followup appears to be the result of loose interactions between proteins and hyaluronic acid. When mixed with the linear hyaluronic acid, synovial fluid becomes less non-Newtonian whereas the non-Newtonian behavior was reinforced when mixed with the cross-linked hyaluronic acid. The rheology was nearly unchanged for all synovial fluids over 6 weeks. Our preliminary trial shows it is possible to study synovial fluid, stored at 4 degrees C, over a long time and suggests the enzymatic degradation of hyaluronic acid is negligible under these experimental conditions.

Effect of polymerized-type I collagen in knee osteoarthritis. II. In vivo study

BACKGROUND

Polymerized-Type I Collagen (Polymerized-Collagen) is an anti-inflammatory and a tissue regenerator biodrug. The aim of the study was to evaluate the efficacy and safety of intra-articular injections of Polymerized-Collagen in patients with knee osteoarthritis (OA).

METHODS AND DESIGN

Patients (n=53) were treated with 12 intra-articular injections of 2 mL of Polymerized-Collagen (n=27) or 2 mL of placebo (n=26) during 6 months. Follow up period was 6 months. The primary endpoints included Western Ontario and McMaster University Osteoarthritis Index, Lequesne index, and pain intensity on a visual analogue scale (VAS). Secondary outcomes were patient global score, investigator global score and drug evaluation. Clinical improvement was determined if the decrease in pain exceeds 20 mm on a VAS and patients achieved at least 20% of improvement from baseline. Urinary levels of C-terminal crosslinking telopeptide of collagen type II (CTXII) and serum high-sensitivity C-reactive protein (hsCRP) were determined by enzyme immunoassays. Statistical analysis was performed by intention to treat.

RESULTS

Polymerized-Collagen was safe and well tolerated. Patients had a statistically significant improvement (P<0.05) from baseline vs. Polymerized-Collagen and vs. placebo at 6 months in: Lequesne Index (13.1+/-0.5 vs. 7.1+/-0.7 vs. 9.6+/-0.8; P=0.027), WOMAC (9.0+/-0.5 vs. 4.0+/-0.6 vs. 5.80+/-0.8; P=0.032), patient VAS (60.0+/-2.6 vs. 20.6+/-2.4 vs. 36.1+/-4.5; P=0.003), physician VAS (49.8+/-1.9 vs. 16.8+/-2.9 vs. 29.8+/-2.9; P=0.002), patient global score (1.08+/-0.1 vs. 2.7+/-0.1 vs. 1.9+/-0.2; P=0.028) and analgesic usage (30.1+/-9.4 vs. 11.0+/-3.4 vs. 17.9+/-4.9; P=0.001). This improvement was persistent during the follow up. A threefold increase in CTXII was determined in placebo group. No differences were found on hs CRP and incidence of adverse events between groups.

CONCLUSION

Polymerized-Collagen is safe and effective in the treatment of knee OA.

Arthroscopic debridement of the osteoarthritic knee combined with hyaluronic acid (Orthovisc) treatment: a case series and review of the literature

Objective

An evaluation of safety and efficacy of high molecular weight hyaluronan (HA) delivered at the time of arthroscopic debridement of the osteoarthritic knee.

Methods

Thirty consecutive patients who met inclusion and exclusion criteria underwent arthroscopic debridement by a single surgeon and concomitant delivery of 6 ml/90 mg HA (Orthovisc^®). These patients were evaluated preoperatively, at 6 weeks, 3 and 6 months post-operatively. Evaluations consisted of WOMAC pain score, SF-36 Physical Component Summary (PCS) score and complications.

Results

No complications occurred during this study. Pre-op average WOMAC pain score was 6.8 +/- 3.5 (n = 30) with a reduction to 3.4 +/- 3.1 at 6 weeks (n = 27). Final average WOMAC pain score improved to 3.2 +/- 3.8 at six months (n = 23). No patients had deterioration of the WOMAC pain score. Mean pre-operative SF-36 PCS score was 39.0 +/- 10.4 with SF-36 PCS score of the bottom 25th percentile at 29.9 (n = 30). Post procedure and HA delivery, mean PCS score at 6 weeks improved to 43.7 +/- 8.0 with the bottom 25th percentile at 37.5 (n = 27). At 6 months, mean PCS score was 48.0 +/- 9.8 with the bottom 25th percentile improved to 45.8 (n = 23).

Conclusion

The results show that concomitant delivery of high molecular weight hyaluronan (Orthovisc^® – 6 ml/90 mg) is safe when given at the time of arthroscopic debridement of the osteoarthritic knee. By delivering HA (Orthovisc^®) at the time of the arthroscopic debridement, there may be a decreased risk of joint infection and/or injection site pain. Furthermore, the combination of both procedures show efficacy in reducing WOMAC pain scores and improving SF-36 PCS scores over a six month period.

The role of viscosupplementation in the ankle using hylan G-F 20

The use of intra-articular injections of high molecular weight elastoviscous solutions of hyaluronan or hylans (cross-linked derivatives of hyaluronan) to treat arthritis is termed viscosupplementation. The function of viscosupplementation is to restore the rheologic properties of synovial fluid. Although anecdotal data exist, no long-term studies regarding the use of viscosupplementation in the ankle have been published to date. The goal of this clinical trial was to compare pain reduction following ankle arthroscopy versus that following ankle arthroscopy combined with weekly intra-articular instillation of hylan G-F 20 during the first 3 postoperative weeks. In the series of patients described in this report, we found that both treatment groups experienced statistically significantly decreased pain following the intervention (P = .002 and P = .0009 for the arthroscopy alone and arthroscopy plus hylan groups, respectively), and that those who received 3 intra-articular injections of hylan G-F 20 following ankle arthroscopy improved statistically significantly (P = .0014) more than did those who underwent arthroscopy as a sole therapy. These preliminary results suggest that viscosupplementation combined with arthroscopy may be more beneficial than arthroscopy alone, and provide further insight into the role of viscosupplementation in the treatment of ankle osteoarthritis.

LEVEL OF CLINICAL EVIDENCE

4.

Effect of intra-articular injection of hyaluronic acid in rheumatoid arthritis patients with knee osteoarthritis

BACKGROUND

Intra-articular injection of hyaluronic acid (HA) is a well-documented treatment for knee osteoarthritis (OA). One of the multifactorial mechanisms is that exogenous HA can stimulate endogenous HA production. HA can regulate the growth and function of chondrocytes by binding to CD44 receptors on the chondrocytes. Synovitis is often found in patients with rheumatoid arthritis (RA) and is supposed to result from CD44 activity. The aim of this study was to investigate the effect of intra-articular injection of HA in patients with RA combined with knee OA.

METHODS

Twenty RA patients with OA knees were enrolled; 11 patients were placed into a stage II group and 9 into a stage III group, in accordance with the Kellgren-Lawrence classification of knee OA. All patients received intra-articular injection of HA (ARTZ) once a week for 5 weeks, and were evaluated with the WOMAC index (including the pain, stiffness and physical function subscales) at baseline, week 5 and week 9. The Friedman test and Wilcoxon signed rank test with Bonferroni correction method were used for statistical analysis.

RESULTS

The effect of intra-articular injection of HA was significant at week 5 (p < 0.0167) and persisted to week 9 (p < 0.0167). This therapy was equally efficacious with stage II and stage III patients, with no difference between the 2 groups.

CONCLUSION

Intra-articular injection of HA was beneficial in patients with RA combined with knee OA.

Efficacy of Hylan G-F 20 and Sodium Hyaluronate in the treatment of osteoarthritis of the knee -- a prospective randomized clinical trial

In this independent prospective randomized trial, we compared the clinical effectiveness, functional outcome and patient satisfaction following intra articular injection with two viscosupplementation agents - Hylan G-F-20 (n=199) and Sodium Hyaluronate (n=193) in patients with osteoarthritis (OA) of the knee. All patients were prospectively reviewed by blinded independent assessors at pre injection, 6 weeks, 3, 6, 12 months. Knee pain and patient satisfaction were measured on a visual analogue scale. Functional outcome was assessed using WOMAC, Oxford knee score and EuroQol EQ-5D scores. Knee pain on VAS improved from 6.7 to 3.2 by 6 weeks (p=0.02) and was sustained until 12 months (3.7, p=0.04) with Hylan G-F 20. In the Sodium Hyaluronate group, pain improved from 6.6 to 5.7 at 6 weeks (p>0.05) and to 4.1 at 3 months (p=0.04) but was sustained only until 6 months (5.9, p>0.05). Improvement in the WOMAC pain subscale was significantly superior in the Hylan G-F 20 group at 3 months (p=0.02), 6 months (p=0.01) and 12 months (p=0.007). There was no significant difference in the EQ-5D scores at 6 weeks and 3 months between the two groups. The numbers of treatment related adverse events were higher (39 vs. 30) in the Hylan G-F 20 group. One patient in the Hylan G-F 20 group who had a serious adverse event was also included in the final analysis. Although both treatments offered significant pain reduction, it was achieved earlier and sustained for a longer period with Hylan G-F 20. From this study, it appeared that the clinical effectiveness and general patient satisfaction are better amongst patients who received Hylan G-F 20.

An amidated carboxymethylcellulose hydrogel for cartilage regeneration

An amidic derivative of carboxymethylcellulose was synthesized (CMCA). The new polysaccharide was obtained by converting a large percentage of carboxylic groups ( approximately 50%) of carboxymethylcellulose into amidic groups rendering the macromolecule quite similar to hyaluronan. Then, the polysaccharide (CMCA) was crosslinked. The behavior of CMCA hydrogel towards normal human articular chondrocytes (NHAC) was in vitro studied monitoring the cell proliferation and synthesis of extra cellular matrix (ECM) components and compared with a hyaluronan based hydrogel (Hyal). An extracellular matrix rich in cartilage-specific collagen and proteoglycans was secreted in the presence of hydrogels. The injectability of the new hydrogels was also analysed. An experimental in vivo model was realized to study the effect of CMCA and Hyal hydrogels in the treatment of surgically created partial thickness chondral defects in the rabbit knee. The preliminary results pointed out that CMCA hydrogel could be considered as a potential compound for cartilage regeneration.

Hyaluronic acid inhibits mRNA expression of proinflammatory cytokines and cyclooxygenase-2/prostaglandin E(2) production via CD44 in interleukin-1-stimulated subacromial synovial fibroblasts from patients with rotator cuff disease

A growing body of evidence supports use of intraarticular hyaluronic acid (HA) injection in patients with rotator cuff disease. However, the mechanism of its anti-inflammatory action has not been clarified. We examined the effects of HA on the expression of mRNAs for proinflammatory cytokines (IL-1beta, IL-6, and TNF-alpha and COX-2/PGE(2) production in IL-1-stimulated subacromial-synovium fibroblasts (SSF) derived from patients with rotator cuff disease. Various concentrations of HA were added to monolayer SSF cultures in the presence of IL-1beta. Gene expression levels were analyzed by quantitative real-time reverse transcription-polymerase chain reaction. Intracellular production of COX-2 was identified by Western blotting. PGE(2) concentrations in the culture media were measured by ELISA. CD44 blocking with OS/37 was performed to investigate the mechanism of action of HA. Immunofluorescence cytochemistry confirmed binding of HA and the presence of CD44 on SSF. Exogenous HA significantly and dose-dependently decreased expression of proinflammatory cytokine mRNAs and COX-2/PGE(2) production in IL-1-stimulated SSF. Pretreatment with OS/37 reversed the inhibitory effects of HA. These results provide a basis for explaining why HA is effective for the treatment of rotator cuff disease.

Intra-articular hyaluronic acid for treatment of osteoarthritis: a nationwide study among the older population of Taiwan

Background

Although intra-articular treatment with hyaluronic acid (HA) for symptomatic osteoarthritis has become widely accepted in recent decades, the pattern of its use has seldom been reported. We have explored the epidemiology of intra-articular HA treatment in Taiwan by using the rich data source from nationwide insurance claims.

Methods

Taiwan's National Health Insurance (NHI), which covers 97% of inhabitants, offers extensive hospitalisation and ambulatory care. We identified the beneficiaries aged 60 years and older who received intra-articular HA within the NHI during 2004. The number of visits in which HA was administered were analysed by patient's age and gender and by the physician's specialty and practice site.

Results

Among the 73,410,777 ambulatory visits by 2,909,219 beneficiaries aged 60 years and older in 2004, 35,782 (1.2%) patients received intra-articular HA treatment in 205,012 (0.3%) visits. The highest prevalence of HA use was in the 70–79 year age group in both sexes. Women received intra-articular HA treatment more frequently than men in all age groups, especially in the 60–69 and 70–79 year groups (1.6% vs. 0.5%, 2.2% vs. 1.0%, respectively). Most intra-articular HA procedures were performed by orthopaedic surgeons (75.1%) and physical medicine and rehabilitation physicians (15.2%), and at metropolitan hospitals (34.5%) and local community hospitals (38.2%).

Conclusion

One out of 100 older patients in Taiwan received intra-articular HA treatment for osteoarthritis of the knee during the course of the year. There were age-gender differences in use of HA treatment. The completion rate of this treatment in our study was high, and thus intra-articular HA might be a good alternative for patients for whom conventional treatment fails. Further research is needed to examine the age-gender differences in use of intra-articular HA in Taiwan.

Effect of a natural extract of chicken combs with a high content of hyaluronic acid (Hyal-Joint) on pain relief and quality of life in subjects with knee osteoarthritis: a pilot randomized double-blind placebo-controlled trial

Background

Intra-articular hyaluronic acid represents a substantive addition to the therapeutic armamentarium in knee osteoarthritis. We examined the effect of dietary supplementation with a natural extract of chicken combs with a high content of hyaluronic acid (60%) (Hyal-Joint^®) (active test product, AP) on pain and quality of life in subjects with osteoarthritis of the knee.

Methods

Twenty subjects aged ≥40 years with knee osteoarthritis (pain for at least 15 days in the previous month, symptoms present for ≥6 months, Kellgren/Lawrence score ≥2) participated in a randomized double-blind controlled trial. Ten subjects received AP (80 mg/day) and 10 placebo for 8 weeks. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and quality of life by the Short Form-36 (SF-36v2) were administered at baseline and after 4 and 8 weeks of treatment.

Results

WOMAC pain (primary efficacy variable) was similar in both study groups (mean [SD]) with 6.6 (4.0) points in the AP group and 6.4 (2.7) in the placebo group (P = 0.943). As compared with baseline, subjects in both groups showed statistically significant improvements in WOMAC pain, stiffness, physical function subscales, and in the aggregate score, but the magnitude of changes was higher in the AP group for WOMAC physical function (-13.1 [12.0] vs. -10.1 [8.6], P = 0.575) and total symptoms (-18.6 [16.8] vs. -15.8 [11.4], P = 0.694). At 4 weeks, statistically significant mean changes compared with baseline were observed in the SF-36v2 scales of role-physical, bodily pain, social functioning and role-emotional among subjects in the AP group, and in physical functioning, bodily pain, and social functioning in the placebo group. At 8 weeks, changes were significant for role-physical, bodily pain, and physical component summary in the AP group, and for physical functioning and role-emotional in the placebo arm. Changes in bodily pain and social functioning were of greater magnitude in subjects given AP.

Conclusion

This pilot clinical trial showed that daily supplementation with oral hyaluronic acid from a natural extract of chicken combs (Hyal-Joint^®) was useful to enhance several markers of quality of life in adults with osteoarthritis of the knee. The results warrant further study in larger sample sizes.

Hylan versus corticosteroid versus placebo for treatment of basal joint arthritis: a prospective, randomized, double-blinded clinical trial

PURPOSE

Conservative, nonsurgical therapies for basal joint osteoarthritis, such as thumb spica splinting and intra-articular corticosteroid injections, remain the mainstays for symptomatic treatment. This study compares intra-articular hylan, corticosteroid, and placebo injections with regard to pain relief, strength, symptom improvement, and metrics of manual function in a randomized, controlled, double-blinded study.

METHODS

Sixty patients with basal joint arthritis were randomized to receive 2 intra-articular hylan injections 1 week apart, 1 placebo injection followed by 1 corticosteroid injection 1 week later, or 2 placebo injections 1 week apart. Patients were evaluated at 2, 4, 12, and 26 weeks and assessed with Visual Analog Scale pain scores, strength measures, difference scores, Disabilities of the Arm, Shoulder, and Hand (DASH) scores, and range of motion measurements.

RESULTS

All groups reported pain relief at 2 weeks. The steroid and placebo groups had significantly less pain at week 4 compared with baseline, but this effect disappeared by week 12. Only hylan injections continued to provide pain relief at 12 and 26 weeks compared with baseline. There were no significant differences in pain between groups at any time. At 12 and 26 weeks, the hylan group had improved grip strength compared with baseline, whereas the steroid and placebo groups were weaker. At 4 weeks, the steroid group reported in the difference score a greater improvement in symptoms (68%) compared with the hylan (44%) and placebo (50%) groups. Whereas at 26 weeks the hylan group reported the largest improvement in symptoms (68%), this was not statistically different from the placebo (47%) and steroid (58%) groups. There were no significant differences in Disabilities of the Arm, Shoulder, and Hand scores or range of motion among the groups. There were no complications from any injection.

CONCLUSIONS

There were no statistically significant differences among hylan, steroid, and placebo injections for most of the outcome measures at any of the follow-up time points. However, based on the durable relief of pain, improved grip strength, and the long-term improvement in symptoms compared with preinjection values, hylan injections should be considered in the management of basal joint arthritis of the thumb.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic I.

The effects of anti-adhesion materials in preventing postoperative adhesion in abdominal cavity (anti-adhesion materials for postoperative adhesions)

PURPOSE

The purpose of this study was to compare the effects of anti-adhesion materials in postoperative adhesions.

MATERIALS AND METHODS

Rats were assigned to five groups: Group 1: Control. Group 2: chitin layers were used. Group 3: Na-hyaluronate / carboxymethylcellulose layers were used. Group 4: Na-hyaluronate gel was poured into the abdomen. Group 5: methylprednisolone was injected. The adhesion frequency and grade were scored according to Granat. Blood was taken for Hb, AST, BUN and albumin levels determination.

FINDINGS

The adhesion frequencies (right and left) and grades were as follow in Groups; I: 82%, 91%, 2.63 +/- 1.22; II: 8.3%, 25%, 0.58 +/- 0.66; III: 17%, 33%, 1.08 +/- 1.08; IV: 50%, 58%, 1.41 +/- 1.44; V: 50%, 42%, 1.41 +/- 1.50. The adhesion phase in all study groups was found significantly low compared to control group, p < 0.05. No difference was observed among serologic and hematological parameters in all groups.

CONCLUSION

All the materials used significantly lowered the adhesion frequency and grade.

Inflammatory and immunological responses to hyaluronan preparations. Study of a murine biocompatibility model

BACKGROUND

Intra-articular injection of hyaluronan preparations is a popular treatment for osteoarthritis of the knee. Recently, clinical reports have described acute inflammatory reactions in joints following these injections. The purpose of this study was to use a murine pouch model to study the local inflammatory and possibly immunological effects of three commercially available hyaluronan-derived products.

METHODS

Each of three different hyaluronan products (Synvisc, Hyalgan, and Supartz) was injected into air pouches established in groups of BALB/c mice. A positive control group (with particle-induced inflammation) and a negative control group (injected with saline solution) were also included. After fourteen days, the mice were killed and the air pouches were explanted and prepared for histological evaluation of the local inflammatory reaction. The antibody response was measured with use of ELISA (enzyme-linked immunosorbent assay) of serum samples obtained after the mice were killed.

RESULTS

Histological analysis revealed a significant increase in total membrane cellularity (p < 0.001 to p < 0.03) after the use of all hyaluronan preparations. The increased cellularity was attributed to an inflammatory cell influx, rather than accumulation of fibroblasts, and elevated lymphocyte counts were observed in membranes stimulated by Synvisc (hylan G-F 20). The ELISA data revealed an antibody response to the Synvisc preparation. This immunological response was directed against a non-hyaluronan portion of the product, as indicated by the lack of cross-reactivity with the other hyaluronan products.

CONCLUSIONS

These findings demonstrate that all three hyaluronan preparations, as currently manufactured, can cause an inflammatory soft-tissue reaction, but only the non-hyaluronan portion of the Synvisc product created an immunological response. It appears likely that this component may be the target of adverse responses in patients.

Hyaluronan: pharmaceutical characterization and drug delivery

Hyaluronic acid (HA), is a polyanionic polysaccharide that consists of N-acetyl-D-glucosamine and beta-glucoronic acid. It is most frequently referred to as hyaluronan because it exists in vivo as a polyanion and not in the protonated acid form. HA is distributed widely in vertebrates and presents as a component of the cell coat of many strains of bacteria. Initially the main functions of HA were believed to be mechanical as it has a protective, structure stabilizing and shock-absorbing role in the body. However, more recently the role of HA in the mediation of physiological functions via interaction with binding proteins and cell surface receptors including morphogenesis, regeneration, wound healing, and tumor invasion, as well as in the dynamic regulation of such interactions on cell signaling and behavior has been documented. The unique viscoelastic nature of hyaluronan along with its biocompatibility and nonimmunogenicity has led to its use in a number of cosmetic, medical, and pharmaceutical applications. More recently, HA has been investigated as a drug delivery agent for ophthalmic, nasal, pulmonary, parenteral, and dermal routes. The purpose of our review is to describe the physical, chemical, and biological properties of native HA together with how it can be produced and assayed along with a detailed analysis of its medical and pharmaceutical applications.

Viscosupplementation for the treatment of osteoarthritis of the knee

BACKGROUND

Osteoarthritis (OA) is the most prevalent chronic joint disorder worldwide and is associated with significant pain and disability.

OBJECTIVES

To assess the effects of viscosupplementation in the treatment of OA of the knee. The products were hyaluronan and hylan derivatives (Adant, Arthrum H, Artz (Artzal, Supartz), BioHy (Arthrease, Euflexxa, Nuflexxa), Durolane, Fermathron, Go-On, Hyalgan, Hylan G-F 20 (Synvisc Hylan G-F 20), Hyruan, NRD-101 (Suvenyl), Orthovisc, Ostenil, Replasyn, SLM-10, Suplasyn, Synject and Zeel compositum).

SEARCH STRATEGY

MEDLINE (up to January (week 1) 2006 for update), EMBASE, PREMEDLINE, Current Contents up to July 2003, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Specialised journals and reference lists of identified randomised controlled trials (RCTs) and pertinent review articles up to December 2005 were handsearched.

SELECTION CRITERIA

RCTs of viscosupplementation for the treatment of people with a diagnosis of OA of the knee were eligible. Single and double-blinded studies, placebo-based and comparative studies were eligible. At least one of the four OMERACT III core set outcome measures had to be reported (Bellamy 1997).

DATA COLLECTION AND ANALYSIS

Each trial was assessed independently by two reviewers for its methodological quality using a validated tool. All data were extracted by one reviewer and verified by a second reviewer . Continuous outcome measures were analysed as weighted mean differences (WMD) with 95% confidence intervals (CI). However, where different scales were used to measure the same outcome, standardized mean differences (SMD) were used. Dichotomous outcomes were analyzed by relative risk (RR).

MAIN RESULTS

Seventy-six trials with a median quality score of 3 (range 1 to 5) were identified. Follow-up periods varied between day of last injection and eighteen months. Forty trials included comparisons of hyaluronan/hylan and placebo (saline or arthrocentesis), ten trials included comparisons of intra-articular (IA) corticosteroids, six trials included comparisons of nonsteroidal anti-inflammatory drugs (NSAIDs), three trials included comparisons of physical therapy, two trials included comparisons of exercise, two trials included comparisons of arthroscopy, two trials included comparisons of conventional treatment, and fifteen trials included comparisons of other hyaluronans/hylan. The pooled analyses of the effects of viscosupplements against 'placebo' controls generally supported the efficacy of this class of intervention. In these same analyses, differential efficacy effects were observed for different products on different variables and at different timepoints. Of note is the 5 to 13 week post injection period which showed a percent improvement from baseline of 28 to 54% for pain and 9 to 32% for function. In general, comparable efficacy was noted against NSAIDs and longer-term benefits were noted in comparisons against IA corticosteroids. In general, few adverse events were reported in the hyaluronan/hylan trials included in these analyses.

AUTHORS' CONCLUSIONS

Based on the aforementioned analyses, viscosupplementation is an effective treatment for OA of the knee with beneficial effects: on pain, function and patient global assessment; and at different post injection periods but especially at the 5 to 13 week post injection period. It is of note that the magnitude of the clinical effect, as expressed by the WMD and standardised mean difference (SMD) from the RevMan 4.2 output, is different for different products, comparisons, timepoints, variables and trial designs. However, there are few randomised head-to-head comparisons of different viscosupplements and readers should be cautious, therefore, in drawing conclusions regarding the relative value of different products. The clinical effect for some products, against placebo, on some variables at some timepoints is in the moderate to large effect-size range. Readers should refer to relevant tables to review specific detail given the heterogeneity in effects across the product class and some discrepancies observed between the RevMan 4.2 analyses and the original publications. Overall, the analyses performed are positive for the HA class and particularly positive for some products with respect to certain variables and timepoints, such as pain on weight bearing at 5 to 13 weeks postinjection. In general, sample-size restrictions preclude any definitive comment on the safety of the HA class of products; however, within the constraints of the trial designs employed no major safety issues were detected. In some analyses viscosupplements were comparable in efficacy to systemic forms of active intervention, with more local reactions but fewer systemic adverse events. In other analyses HA products had more prolonged effects than IA corticosteroids. Overall, the aforementioned analyses support the use of the HA class of products in the treatment of knee OA.

Septic knee arthritis after intra-articular hyaluronate injection

Intraarticular sodium hyaluronate injection to treat osteoarthritis is associated with minor side effects. Infections seem uncommon. We report two cases of septic knee arthritis. One patient was an 80-year-old woman who was admitted for Staphylococcus aureus knee arthritis after several intraarticular injections of sodium hyaluronate and corticosteroids. In the other patient, a 78-year-old woman, Neisseria mucosa knee arthritis occurred after a single sodium hyaluronate injection. Faultless aseptic technique is essential when administering hyaluronate viscosupplementation. Patients should be informed of the risk of septic arthritis.

Intra-articular hyaluranic acid compared with progressive knee exercises in osteoarthritis of the knee: a prospective randomized trial with long-term follow-up

The goal of this study was to determine whether hyaluronic acid (HA) or progressive knee exercises (PE) can improve functional parameters in patients with osteoarthritis (OA) of the knee. In a prospective clinical trial 200 knees (105 patients) with radiographic Kellgren Lawrence grade III OA were randomized and received either three intra-articular injections of hyaluronic acid (Hylan G-F 20) at one-week intervals or PE for 6 weeks. Patients were evaluated by use of the Hospital for Special Surgery (HSS) Knee Score and followed-up for 18 months. Total HSS score for HA and PE patients improved from 62.6 +/- 13.8 to 88.8 +/- 11.1 and from 65.4 +/- 12.3 to 88.3 +/- 9.1, respectively, at the end of the trial (P < 0.01). There were no statistically significant differences between the groups. Twenty-one patients of the HA group were excluded from the study because they had received another form of therapy. All patients in the PE group completed the trial. The patients who dropped out had also significant improvement from 57.0 +/- 12.9 to 76.7 +/- 11.9 (P < 0.01). This prospective randomized trial confirmed that both HA injections and PE result in functional improvement. HA injections also increase the levels of satisfaction of the OA patients.

Hyaluronic acid: a unique topical vehicle for the localized delivery of drugs to the skin

Hyaluronic acid (HA) is a naturally occurring polyanionic, polysaccharide that consists of N-acetyl-D-glucosamine and beta-glucoronic acid. It is present in the intercellular matrix of most vertebrate connective tissues especially skin where it has a protective, structure stabilizing and shock-absorbing role. The unique viscoelastic nature of HA along with its biocompatibility and non-immunogenicity has led to its use in a number of clinical applications, which include: the supplementation of joint fluid in arthritis; as a surgical aid in eye surgery; and to facilitate the healing and regeneration of surgical wounds. More recently, HA has been investigated as a drug delivery agent for various routes of administration, including ophthalmic, nasal, pulmonary, parenteral and topical. In fact, regulatory approval in the USA, Canada and Europe was granted recently for 3% diclofenac in 2.5% HA gel, Solaraze, for the topical treatment of actinic keratoses, which is the third most common skin complaint in the USA. The gel is well tolerated, safe and efficacious and provides an attractive, cost-effective alternative to cryoablation, curettage or dermabrasion, or treatment with 5-fluorouracil. The purpose of this review is to describe briefly the physical, chemical and biological properties of HA together with some details of its medical and pharmaceutical uses with emphasis on this more recent topical application.

Successful nonoperative management of chronic osteoarthritis pain of the knee: safety and efficacy of retreatment with intra-articular hyaluronans

CONTEXT

Although there are many nonsurgical therapies available for the treatment of pain associated with osteoarthritis (OA), their long-term use and safety have not been systematically followed. Intra-articular hyaluronan therapy has been used in the treatment of symptoms associated with OA of the knee with a very favorable safety profile. Five intra-articular hyaluronan products are approved in the US. No systematic review of the safety and efficacy of their chronic use has been reported.

OBJECTIVE

To evaluate the literature on the efficacy and safety of repeat courses of hyaluronan therapy in patients with OA of the knee.

DATA SOURCES

MEDLINE, EMBASE, searched through October 2004.

STUDY SELECTION

Databases were searched using the terms hyaluronan, sodium hyaluronate, hyaluronic acid, hylan, hylan G-F 20, osteoarthritis, adverse events, repeat treatment, and multiple courses.

DATA SYNTHESIS

There are some data that support the benefit and safety of repeat treatment for all products. Data also indicate that one formulation of sodium hyaluronate (molecular weight [MW] 500-730 kDa) is well tolerated and as effective after multiple courses of treatment as it is after a single course. There is also clinical evidence that prolonged use of sodium hyaluronate (MW 500-730 kDa) may significantly decrease the rate of deterioration of joint structure. Localized severe acute inflammatory reactions reported with repeated treatment in some patients are not a class effect but may be linked to physicochemical characteristics of hylan-based treatment.

CONCLUSIONS

Repeat courses of the hyaluronans are safe and effective in the treatment of pain associated with OA of the knee.

A prospective randomised controlled clinical trial comparing the efficacy of different molecular weight hyaluronan solutions in the treatment of knee osteoarthritis

Viscosupplementation consists of injecting exagenous hyaluronan (HA) into the synovial joints to restore the normal rheological environment which deteriorates severely in osteoarthritic (OA) joints. Efficacy might be related to the rheological properties and molecular weight (MW) of the hyaluronan preparations. This prospective, controlled, double-blind, randomised clinical trial was aimed at comparing the elastoviscous properties of a high molecular weight viscosupplement, hylan G-F 20, with that of a lower molecular weight hyaluronan product in order to determine the relationship of elastoviscosity to efficacy, alongside placebo, in the treatment of patients with knee OA. The results were analysed as a "completers" analysis with 59 patients. Primary outcome measures included the Western Ontario and Mc Master Universities' Osteoarthritis Index (WOMAC) for pain, stiffness and function scores, and patient and physician global assessments (0-100 scale). For patient (PGA) and physician global assessments (PhGA), the 0-100 scale was used, with 100 being the worst. Follow-up assessments were made at intervals of 1, 3 and 6 months after the first injection. Local adverse events, such as transient pain at the injection site or warm knee lasting for one night, were recorded in two patients (3%). In all groups, the WOMAC pain score exhibited a significant difference from the baseline value; neither treatment group was significantly different from the placebo group, but total pain score was significantly better than baseline for both of the HA groups at the end of 6 months (p < 0.05). Improvement in WOMAC physical function score favoured both sodium hyaluronate and hylan G-F 20 after the first month, and remained significant until the end of 6 months (p < 0.01). In the placebo group, the physical function scores became worse after the end of the 1st month; the scores at the end of 6 months were no different from those at the beginning. The WOMAC stiffness scores of both of the hyaluronic acid groups improved with the first injection, and remained significantly better than the placebo group until the end of the survey (p < 0.001). All groups expressed improvement with PGA scores after the first injection. At the end of 6 months all three groups were similar, but the treatment groups were significantly better than the placebo group (p < 0.05), and all were significantly better than at the beginning (p < 0.05). The PhGA scores were similar in all groups until after the third injection. The second group was slightly better in the controls at 1 and 3 months, but all the groups were similar at the end of 6 months. Although the placebo group seemed worse, it was not statistically significant. Compared with lower molecular weight HA, the higher molecular weight HA might be more efficacious in treating knee OA, but heterogeneity of previous studies limited definitive conclusions. Patients treated by injection of either of two hyaluronan preparations showed clinical improvement for pain, though no different from the placebo group; WOMAC stiffness scores were better than placebo in the HA groups, whereas PGA scores showed improvement in all groups but HA groups were better than placebo. PhGA scores were worse in the placebo group, but not to a statistically-significant extent. The HA groups did not differ in terms of clinical efficacy.

Viscosupplementation for the treatment of osteoarthritis of the knee

BACKGROUND

Osteoarthritis (OA) is the most prevalent chronic joint disorder worldwide and is associated with significant pain and disability.

OBJECTIVES

To assess the effects of viscosupplementation in the treatment of OA of the knee. The products were hyaluronan and hylan derivatives (Adant, Arthrum H, Artz (Artzal, Supartz), BioHy (Arthrease), Durolane, Fermathron, Go-On, Hyalgan, Hylan G-F 20 (Synvisc Hylan G-F 20), NRD-101, Orthovisc, Ostenil, Replasyn, SLM-10, Suplasyn, Synject and Zeel compositum).

SEARCH STRATEGY

MEDLINE, EMBASE, PREMEDLINE, Current Contents up to July 2003, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched. Specialised journals and reference lists of identified randomised controlled trials (RCTs) and pertinent review articles up to April 2004 were handsearched.

SELECTION CRITERIA

RCTs of viscosupplementation for the treatment of people with a diagnosis of OA of the knee were eligible. Single and double-blinded studies, placebo-based and comparative studies were eligible. At least one of the four OMERACT III core set outcome measures had to be reported (Bellamy 1997).

DATA COLLECTION AND ANALYSIS

Each trial was assessed independently by two reviewers (NB, JC) for its methodological quality using a validated tool. All data were extracted by one reviewer (JC) and verified by a second reviewer (VR). Continuous outcome measures were analysed as weighted mean differences (WMD) with 95% confidence intervals (CI). Dichotomous outcomes were analyzed by relative risk (RR).

MAIN RESULTS

Sixty-three trials with a median quality score of 3 (range 1 to 5) were identified. Follow-up periods varied between day of last injection and one year. Thirty-seven trials included comparisons of hyaluronan/hylan and placebo, nine trials included comparisons of intra-articular (IA) corticosteroids, and five trials included comparisons of nonsteroidal anti-inflammatory drugs (NSAIDs). The pooled analyses of the effects of viscosupplements against 'placebo' controls generally supported the efficacy of this class of intervention. In these same analyses, differential efficacy effects were observed for different products on different variables and at different timepoints. Of note is the 5 to 13 week post injection period which showed a percent improvement from baseline of 11 to 54% for pain and 9 to 15% for function. In general, comparable efficacy was noted against NSAIDs and longer-term benefits were noted in comparisons against IA corticosteroids. In general, few adverse events were reported in the hyaluronan/hylan trials included in these analyses.

AUTHORS' CONCLUSIONS

Based on the aforementioned analyses, viscosupplementation is an effective treatment for OA of the knee with beneficial effects: on pain, function and patient global assessment; and at different post injection periods but especially at the 5 to 13 week post injection period. It is of note that based on non-randomised groups, the magnitude of the clinical effect, as expressed by the WMD and standardised mean difference (SMD) from the RevMan 4.1 output, is different for different products, comparisons, timepoints, variables and trial designs. However, there are few randomised head-to-head comparisons of different viscosupplements and readers should be cautious, therefore, in drawing conclusions regarding the relative value of different products. The clinical effect for some products, against placebo, on some variables at some timepoints is in the moderate to large effect-size range. Readers should refer to relevant tables to review specific detail given the heterogeneity in effects across the product class and some discrepancies observed between the RevMan 4.1 analyses and the original publications. Overall, the analyses performed are positive for the HA class and particularly positive for some products with respect to certain variables and timepoints, such as pain on weight bearing at 5 to 13 weeks postinjection. In general, sample-size restrictions preclude any definitive comment on the safety of the HA class of products; however, within the constraints of the trial designs employed no major safety issues were detected. In some analyses viscosupplements were comparable in efficacy to systemic forms of active intervention, with more local reactions but fewer systemic adverse events. In other analyses HA products had more prolonged effects than IA corticosteroids. Overall, the aforementioned analyses support the use of the HA class of products in the treatment of knee OA.

Granulomatous synovitis after intraarticular Hylan GF-20. A report of two cases

Intraarticular hyaluronan injections are used to treat osteoarthritis of the knee. Acute painful swelling with a joint effusion develops locally after the injection in about 10% of cases but resolves spontaneously. Crystals are identifiable in some patients, but the mechanism in crystal-negative cases remains unknown. We report knee arthritis with inflammatory joint fluid free of organisms and crystals in two patients after Hylan GF-20 treatment for femorotibial osteoarthritis. Synovial membrane histology disclosed granulomatous synovitis with epithelioid histiocytic and multinucleate giant cells but no visible foreign bodies. These two cases suggest that crystal-negative arthritis after Hylan GF-20 injection may be ascribable to granulomatous synovitis of the foreign-body giant-cell type.

Comparative study of hyaluronic derivatives: rheological behaviour, mechanical and chemical degradation

Depolymerisation by oxytetracycline (OTC) as well as the progressive cleavage of hyaluronic acid induced by ultrasound was investigated in nine commercially available hyaluronic polymers. Sample solutions differed in molecular weight, from 500 to 7000 kDa, and in their source. The hyaluronic acid concentration in each sample was analysed by HPLC. The concentration range was over 8.39-10.18 mg ml(-1) in samples with a nominal concentration of 1%, and 14.05 mg ml(-1) in one sample with a nominal concentration of 1.5%. It was found that stability was dependent on both molecular weight and the concentration of the samples. The rheological parameters n (power law index) and K (consistency coefficient) were good predictors regarding the degradation behaviour. Although many factors are involved in obtaining a therapeutic response, the results obtained in this work support the notion that both mechanical and chemical degradation are reduced in hyaluronate solutions with low molecular weight, the final concentration of the product being a critical factor.

The effect of hyaluronic acid with different molecular weights on collagen crosslink synthesis in cultured chondrocytes embedded in collagen gels

Hyaluronic acid (HA) is a component of the extracellular matrix of cartilage and has various effects on three-dimensional cultured chondrocytes. We measured Pyridinoline (Pyr), which is a crosslink of collagen in cultured chondrocyte-collagen composites treated with HA of different molecular weights to investigate the effects of the various molecular weights on collagen crosslink synthesis. The control group was collagen gel without cells; group N was treated without HA; and the others were treated with HA with an average molecular weight of 2.3 x10(6) Da (group H), 8.0 x10(5) Da (group M), and 2.3 x10(4) Da (group L). In the control group, the Pyr content decreased, at week 4, being one-tenth that of preculture levels. In groups H and M, it was significantly greater than that in groups L and N at week 4. Pyr/hydroxyproline, which indicates the concentration of Pyr per collagen, decreased greatly in the control group at week 3. In groups H and M, it was significantly higher than that in groups L and N at week 4 and increased to 80 and 76% of normal rabbit articular cartilage, respectively. The concentration of Pyr per collagen in cultured chondrocyte-collagen composites was similar to that of normal articular cartilage in vivo, and higher molecular weight HA may have a greater effect on the maturation of collagen in the composite.

Non-Animal Stabilized Hyaluronic Acid

Hyaluronic acid (HA) is a major component of human synovial fluid, providing the rheologic properties (elasticity and viscosity) that enable the synovial fluid to perform lubricating and shock-absorbing functions within the healthy joint. Over the last 2 decades, HA preparations have become established in intra-articular therapy of osteoarthritis (OA), particularly OA of the knee. Existing HA preparations, both cross-linked and non-cross-linked, are all administered by courses of multiple injections, and all have been associated with variable success rates. The clinical profile of an HA preparation is inextricably linked to the product's physicochemical properties. For example, the molecular structure of the HA affects the intra-articular residence time, which should in turn influence the duration of action post-injection. Non-animal stabilized hyaluronic acid (NASHA) is a new-generation HA preparation, produced wholly from non-animal sources. NASHA is stabilized using a carefully controlled cross-linking process, which increases the intra-articular residence time from hours to weeks. This facilitates single-injection treatment for OA without affecting the biocompatibility of HA. This review evaluates the properties of NASHA, including the available clinical data, in the context of previously developed HA preparations.

Preliminary results of integrated therapy for patients with knee osteoarthritis

OBJECTIVE

To investigate the effects of integrated therapy on the functional status of patients with knee osteoarthritis (OA).

METHODS

A total of 140 subjects with bilateral knee OA (Altman grade II) were randomized sequentially into 4 groups (groups I-IV). Group I received isokinetic exercises; group II received isokinetic exercise and pulse ultrasound for periarticular soft tissue pain; group III received isokinetic exercise, pulse ultrasound, and intraarticular hyaluronan therapy; and group IV acted as the control group. The therapeutic effects of the interventions were evaluated by changes in Lequesne's index, knee range of motion, peak muscle torques of knee flexion and extension, and ambulation speed after 8 weeks of treatment and at followup 1 year later. In addition, changes in visual analog scale pain and rates of attrition in each group were also recorded.

RESULTS

Patients in groups I-III exhibited increased muscle peak torques and significantly reduced pain and disability after treatment and at followup. Groups II and III showed significant improvements in range of motion and ambulation speed after treatment. Group III also showed the greatest increase in walking speed and decrease in disability after treatment and at followup. Both group II and group III had significant gains in muscular strength after treatment and at followup; group III showed the greatest gains.

CONCLUSION

An integrated therapy deals with the extra- and intraarticular progressive pathologic changes, and kinesiologic management of OA is suggested for the management of knee OA.

Pseudoseptic reactions to hylan viscosupplementation: diagnosis and treatment

Hyaluronans are used widely in the treatment of osteoarthritis of the knee. Three commercial hyaluronan preparations currently are available in the United States: sodium hyaluronate (Hyalgan), sodium hyaluronate (Supartz), and hylan G-F 20 (Synvisc). Although the sodium hyaluronates are derived naturally, hylan is chemically modified to increase its molecular weight. All three products have been shown to be well tolerated in clinical trials, however, there have been reports in the literature of pseudoseptic reactions, or severe acute inflammatory reactions, after injections with hylan. Our study reviewed the reported incidence of pseudosepsis. The pathogenic mechanisms and clinical treatment of this reaction are presented.

Long-term effect of sodium hyaluronate (Hyalgan) on osteoarthritis progression in a rabbit model

BACKGROUND

Intra-articular (IA) hyaluronan (HA) injections are approved for the treatment of knee osteoarthritis (OA) pain. One of the currently available products is approved for repeat treatment courses. While HA is classed as a symptom-modifying agent, there is substantial evidence that this therapeutic modality also possesses disease-modifying activity.

OBJECTIVE

A rabbit model of OA, anterior cruciate ligament transection (ACLT), was used to investigate the long-term effects of single and sequential courses of HA therapy on OA progression.

DESIGN

One or two courses of five weekly IA injections of sodium hyaluronate (Hyalgan) average molecular weight, MW, of 500-730 kDa, or vehicle were administered to rabbits (N=10 per group), initiated 4 and 13 weeks (for groups that received a second course) after ACLT. Gross morphological and histomorphometric evaluations were performed on harvested knee joints following sacrifice at 26 weeks after surgery.

RESULTS

All the rabbits exhibited the characteristic pathologic changes of OA. Rabbits that received one or two courses of HA injections showed less disease progression than rabbits treated with ACLT alone or with 10 vehicle injections. However, rabbits that received five vehicle injections also showed improved morphology compared with those given no injections. Rabbits that received 10 HA injections showed significantly less surface roughness of the femoral cartilage compared with rabbits treated with ACLT, 5 HA injections, or 10 vehicle injections, and showed significantly less surface roughness of the tibial plateau compared with all other treatment groups (P<0.05).

CONCLUSIONS

Repeat courses of HA injections reduced the degree of articular degeneration in a rabbit ACLT model of OA. Sequential courses of HA therapy may be advantageous in the long-term management of OA.

Hyalgan has a dose-dependent differential effect on macrophage proliferation and cell death

The intra-articular injection of high molecular weight hyaluronic acid (HA) has been reported to be an effective treatment for pain of osteoarthritis of the knee. However, the mechanism by which HA exerts its effect is unknown. To explore HA's influence on the growth of U937 human macrophages, cells were incubated for 168 h with three concentrations, 1, 0.1 and 0.01 mg/mL, of Hyalgan, a high molecular weight HA preparation. At 24-h increments, the cells were examined for proliferation, cell cycle distribution as well as the number of apoptotic and dead cells. Exposing macrophages to 1 mg/mL Hyalgan significantly reduced the rate of cellular proliferation and altered the cell cycle distribution to yield decreased proportions of G0/G1 cells but increased S and G2/M cells. Concomitantly, a 10-fold increase in apoptotic cells and a 12-fold increase in dead cells were observed. The population doubling time (PDT) for cells treated with 1.0 mg/mL Hyalgan increased from 23.6 to 52.9 h. By contrast, the two lower Hyalgan concentrations significantly promoted macrophage proliferation in a dose-dependent manner. They also increased the proportion of G2/M cells, but had no effect on the number of apoptotic or dead cells. The PDTs of 21.5 and 22.2 h were less than the control time of 23.6 h. These results demonstrate that Hyalgan concentrations have a differential effect on macrophage growth dynamics and suggest an anti-inflammatory effect at high HA concentrations.