Safety and Efficacy of Hybrid Cooperative Complexes of Sodium Hyaluronate and Sodium Chondroitin for the Treatment of Patients with Symptomatic Knee Osteoarthritis

INTRODUCTION

Knee osteoarthritis (KOA) represents a widespread degenerative disease that causes pain and motor disability. Conservative treatments mainly focus on relieving symptoms, improving joint function, and trying to delay surgery. Safety and efficacy of hybrid cooperative complexes (2.4% sodium hyaluronate and 1.6% sodium chondroitin; HA-SC) for symptomatic KOA were investigated in a single-arm, prospective, pilot study.

METHODS

Patients with a visual analogue scale (VAS) pain score ≥ 4 and Kellgren-Lawrence Grade < 4 received a single intraarticular HA-SC injection. Patients with a VAS score change from baseline ≤ 1 received a second injection at day 30. Device-related adverse events (DR-AEs)/adverse events (AEs) were primary endpoints. Secondary endpoints included Western Ontario and McMaster Universities Osteoarthritis Index LK 3.1 (WOMAC LK 3.1), VAS, patient global assessment of disease status (PtGA), and patient proportion needing a second injection.

RESULTS

Of 83 patients with KOA (Kellgren-Lawrence Grade, 2-3), 34.9% had DR-AEs at day 7. No serious DR-AEs/AEs were reported. A significant (P < 0.0001) reduction over time in VAS pain score plus WOMAC pain, stiffness, physical function limitation, and total scores was reported. Median PtGA scores indicated a 'slight improvement' at most follow-up visits. Only 18.1% of patients required a second injection.

CONCLUSIONS

A single intraarticular HA-SC injection was safe, well-tolerated, and did not lead to major deterioration in terms of reducing knee pain, stiffness, and physical function limitation in patients with symptomatic KOA.

Gait kinematics of osteoarthritic knees after intra-articular viscosupplementation: A double-blinded randomized controlled trial

BACKGROUND

The utilization of subjective questionnaires for assessing conservative treatment in knee osteoarthritis may present challenges in identifying differences due to inadequate statistical power. Objective tools, such as three-dimensional (3D) kinematic analysis, are accurate and reproducible methods. However, no high-quality studies assessing the effects of intra-articular viscosupplementation (VS) have been published. Therefore, the objective of the study was to evaluate gait kinematics of patients with advanced knee osteoarthritis after VS.

METHODS

Forty-two patients were randomized to receive either VS or saline injection (placebo). They underwent 3D kinematic gait analysis before and at 1, 6, and 12 weeks after treatment and knee angles during stance phase were determined. Patients and the healthcare team responsible for data collection, processing, and analysis were blinded to group allocation. Between-group comparisons were conducted using linear mixed models.

RESULTS

Compared with placebo, the VS increased the maximum knee extension (3.2° (0.7-5.7)) and decreased the maximum knee flexion (-3.6° (-6.1 to -1.2)) on the sagittal plane at 1 week. At 6 weeks, the VS group sustained a reduced maximum knee flexion (-2.6° (-5.2 to 0.0)). On the axial plane, the VS group demonstrated an increase in maximum internal rotation at 12 weeks (3.9° (0.3 to 7.7)). The VS group exhibited reduced single-leg stance time at 1 week and increased total stance time at 12 weeks.

CONCLUSIONS

VS led to short- and long-term kinematic improvements in the sagittal and axial planes, leading to a gait pattern closer to that observed in individuals with less severe osteoarthritic knees.

EFFECTIVENESS OF VISCOSUPPLEMENTATION IN THE TREATMENT OF HEMOPHILIC ARTHROPATHY: A SYSTEMATIC REVIEW

Objective

To describe the efficacy of using viscosupplementation in patients with hemophilic arthropathy (HA), on pain, limb functionality, and quality of life.

Methods

A systematic review of the literature was performed following the PRISMA guidelines without limitations of language or year of publication. The search was performed on the following medical databases: PubMed, Cochrane Library, EMBASE, BVS/BIREME, Scopus, Web of Science, EBSCOhost, and PROQUEST in April 2020. The search used the following word: (hemophilia AND joint diseases) OR (haemophilic arthropathy OR hemophilic arthropathy) AND viscosupplementation.

Results

The systematic review identified 127 articles, 10 of which were selected for data extraction and qualitative analysis. The 10 selected articles included 297 joints with HA in 177 hemophilic subjects. Our review showed positive results in alleviating pain and improving functional capacity, and quality of life. No major adverse effects were observed.

Conclusion

There is a lack of scientific evidence regarding viscosupplementation with hyaluronic acid, but the results presented in this research suggest that it is an effective and safe therapeutic option to alleviate pain and improve functional capacity in patients with HA. Level of Evidence II, Systematic Review.

Effectiveness of double-puncture temporomandibular joint arthrocentesis with viscosupplementation in different categories of severity - a prospective study

This 3-year prospective study evaluated the efficacy of temporomandibular joint (TMJ) arthrocentesis with viscosupplementation in different severity stages based on the Dimitroulis classification (categories 2-4 were included). TMJ arthrocentesis was performed under local anaesthesia, and the protocol consisted of a double-puncture technique with lavage of ≥150 cc Ringer Lactate plus viscosupplementation. Incobotulinum toxin A was administered 10-15 days preoperatively in patients with concomitant masticatory myalgia. The primary outcome was TMJ pain, assessed by visual analogue scale (VAS, 0-10), and the secondary outcomes were the maximum mouth opening (MMO, mm) and myalgia degree (0-3). All outcomes were assessed on the intervention day (T0) and after the procedure (T1) (minimum 1 month and then 3 months, 6 months, 1 year and every year since). A total of 108 patients were enrolled (mean age of 43.1 ± 18.9 years); 86 (80%) were women and 22 (20%) were men. Preoperative pain was 4.02 ± 3.12 (mean ± SD), MMO was 38.10 ± 9.56 (mean ± SD) and myalgia degree was 1.80 ± 1.18 (mean ± SD). After an average of 215.4 days (31-1253 days), a statistically significant improvement of pain (P < 0.0001), MMO (P = 0.005) and myalgia degree (P < 0.0001) was observed. The overall successful outcome of TMJ arthrocentesis with viscosupplementation was 76%. The authors observed increased arthrocentesis effectiveness and success rate with viscosupplementation in Dimitroulis category 2 (88.6%) compared to 3-4 (71.4%). An association was found between arthrocentesis with viscosupplementation failure and painful myalgia (ρ = 0.477; P < 0.0001). Thirteen patients (12%) underwent a second TMJ intervention after finalising the present trial. With a low complication rate, TMJ arthrocentesis with viscosupplementation led to an overall benefit for all the included patients. This study reinforces the important role of minimally invasive TMJ arthrocentesis as a first treatment option, with better results in the early stages compared to more severe stages.

Funding has no effect on studies evaluating viscosupplementation for knee osteoarthritis: A systematic review of bibliometrics and conflicts of interest

Background

Viscosupplementation for knee osteoarthritis (OA) may raise concerns regarding conflicts of interest (COI). Evidence of inconclusive study results and publication bias in previous studies has led to concern that financial COI have influenced viscosupplementation outcomes. It is critical to ensure that clinical practice is guided by informed decision making and evidence-based medicine.

Methods

A systematic review was conducted following PRISMA guidelines. PubMed, MEDLINE, and Web of Science databases were searched for articles pertaining to hyaluronic acid (or similarly derived) injections to native knees with primary OA only. Bibliometric data, financial COI, and study outcomes were assessed.

Results

67 studies met inclusion criteria for analysis, 53 of which (79.1%) presented Level I evidence, and 21 of which (31.3%) reported at least one author with COI. All studies reporting COI also disclosed industry funding. There were no relationships between reported COI and study outcomes (Χ ²  = 0.31, P = 0.577), levels of evidence (Χ ²  = 3.48, P = 0.176), or relative citation ratio (RCR) (S = 743, P = 0.591). Studies reporting COIs/industry funding tended to be published in journals with significantly higher impact factors (IF) (reporting COI: IF = 3.5 ± 2.0; no COI: IF = 1.8 ± 1.1; S = 950, P < 0.001). Study outcomes were not related to the probability of being published in an open access journal (Χ ²  = 0.01, P = 0.960), nor to level of evidence (Χ ²  = 2.67, P = 0.263), RCR (S = 618, P = 0.835), or IF (S = 563, P = 0.655).

Conclusions

Investigator COIs (and commercial funding of studies) have not significantly influenced the frequency of favorable outcomes or study level of evidence regarding contemporary viscosupplementation for the treatment of knee OA. Studies reporting COIs/industry funding tended to be published in journals with significantly higher impact factors. Results overwhelmingly supported using viscosupplementation to treat knee OA.

Level of evidence

Level V Systematic Review.

The value of injectable viscoelastic supplements for joints

Intra-articular viscoelastic supplements are commonly administered by musculoskeletal radiologists for the treatment of symptomatic osteoarthritis (OA). This article provides an overview of the putative mechanism of action of the agents, a brief review of the evidence base underlying the practice, a commentary on some of the major society guidelines regarding the treatment, and a description of the adverse events that are associated with intra-articular hyaluronic acid administration.

Efficacy and Safety of Hyaluronic Acid Intra-articular Injection after Arthroscopic Knee Surgery: A Systematic Review and Meta-analysis

OBJECTIVE

Hyaluronic acid (HA) intra-articular injection after arthroscopic knee surgery has been widely applied but its efficacy and safety remain controversial. The aim of this systematic review is to analyze the efficacy and safety of HA intra-articular injection after arthroscopic knee surgery, and to compare the efficacy of HA with different molecular weights.

METHODS

We conducted a systematic literature search in PubMed, Embase, Google scholar and the Cochrane library from inception to 16 September 2022 for English-written articles, in order to identify randomized controlled trials that evaluated the clinical efficacy and/or safety of HA intra-articular injection after arthroscopic knee surgery. Then we meta-analyzed the outcomes of patients given intra-articular HA injections postoperatively and control patients. We also evaluated the influence of HA with different molecular weights. In every calculation, sensitive analysis was performed. The visual analogue scale (VAS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and adverse events were selected as the primary outcome measurements, while Lysholm, International Knee Documentation Committee (IKDC) and Tegner score were selected as the secondary outcome measurements. Publication bias of every outcome was evaluated using egger test.

RESULTS

Fifteen studies involving 951 knees were included and 12 of them were used to performed the meta-analysis. The results showed no significant difference between the HA group and control group according to VAS, whether assessed at less (P = 0.90) or more than 6 months (P = 0.55). Besides, there were no statistical differences between the HA group and control group according to subgroup analysis (Ps = 0.77, 0.91 and 0.81 in anterior cruciate ligament reconstruction, meniscectomy and overall groups, respectively). Compared to control group, the overall effect of WOMAC score showed no significant differences (P = 0.25), nor did in two subgroups (P = 0.37 and P = 0.22). Outcomes measured by Lysholm (P = 0.13), IKDC (P = 0.86) and Tegner (P = 0.42) scores showed no significant differences, either. The analysis of the risk of adverse events indicated no increase in HA groups (P = 0.06). We found no significant differences between high- and low-molecular-weight HA at 6 (P = 0.96) or 12 months (P = 0.93) postoperatively. Two studies failed to pass the sensitive analysis and the reasons were discussed detailly and acceptable publication bias was observed.

CONCLUSIONS

Although HA injection after arthroscopic knee surgery is safe, the available evidence does not support its efficacy in pain relief and functional recovery. Therefore, the application of HA injection after arthroscopic knee surgery is not recommended.

Efficacy of computer-guided versus conventional sodium hyaluronate injection in superior joint space in treatment of temporomandibular joint (TMJ) internal derangement: Comparative randomized controlled trial

OBJECTIVES

evaluate the feasibility and clinical outcomes of computer-guided sodium hyaluronate injection in superior joint space compared to conventional injection for the treatment of TMJ Internal Derangement (TMJ-ID).

PATIENTS AND METHODS

Randomized controlled trial conducted on 40 patients diagnosed with bilateral TMJ-ID divided into two groups. Group A treated with four computer-guided sodium hyaluronate injections in superior TMJ space with one-week intervals. Group B received similar injections but with the conventional method. The intraoperative assessment included total procedural time and patient convenience during the injection. The postoperative evaluation included maximum unassisted mouth opening (MUMO), modified Helkimo's clinical dysfunction index, and pain intensity on a visual analog scale (VAS).

RESULTS

Group A showed better improvement in maximum mouth opening and pain intensity than group B after a week of the second, third and fourth injection. At the six months, group A continued to show better improvement regarding maximum mouth opening, while improvement in pain and TMJ dysfunction was similar in both groups. There were differences between both groups regarding procedural time and patient convenience across the study except the time of the first injection, which was similar in both groups CONCLUSION: Using the virtual planning and injection guide for intra-articular TMJ injection is considered promising to increase the accuracy and efficacy of injectable material securing faster results besides rendering the procedure easily reproducible and simpler to both clinicians and patients. However, the authors could not ensure the long-term superiority of the computer-guided injection technique over the conventional one in light of the results of this study.

A Review of the Clinical Effectiveness and Safety of Hybrid Cooperative Complexes in Intra-articular Viscosupplementation

Viscosupplementation by intra-articular (i.a.) injection of the non-sulfated glycosaminoglycan (GAG) hyaluronic acid (HA) is a conservative therapy widely accepted in clinical practice for the management of osteoarthritis (OA) and joint diseases. The aim of viscosupplementation is to restore the rheological properties of the synovial fluid to relieve joint inflammation and pain and improve joint function through a chondroprotective effect. However, there is a range of hyaluronic acid products for OA that differ in preparation, molecular weight, rheological characteristics and concentration, and different i.a. formulations are more suited to particular patient populations and clinical situations, in part because of anatomical differences between joints. This paper focuses on innovative hybrid cooperative complexes of high and low molecular weight hyaluronic acid (HA-HL) and hyaluronic acid plus sodium chondroitin (HA-SC) that have been developed. Both products are formulated with pharmaceutical-grade, highly purified hyaluronic acid obtained with a multi-step biofermentation process, with properties that make them suitable across a range of degenerative joint diseases. They represent progress in building on the symptomatic and functional benefits of viscosupplementation in joint disease, with the additional beneficial effect of treating the patient with a high concentration of GAGs by a low number of injections. Here, we review the clinical evidence for the efficacy of a hybrid cooperative compound of HA-HL in various degenerative joint diseases, which suggests a synergistic effect of the different molecular weight hyaluronans that together more closely mimic the physiological composition of synovial fluid. Similarly, the evidence shows that HA-SC is safe, effective, and well tolerated in hip OA, with rapid and clinically significant improvements in pain symptoms and functionality. Such innovations in viscosupplementation expand the usefulness of the modality in the management of OA and other joint diseases, complemented by a lack of systemic or local side effects that allow the concurrent use of other drugs if needed.

Intraarticular viscosupplementation following arthroscopic anterior cruciate ligament reconstruction: A systematic review

BACKGROUND

Pain, swelling and joint stiffness are the major problems following arthroscopic ACL reconstruction (ACLR) surgery that restrict early return to sports and athletic activities. The patients often receive prolonged analgesic medications to control the inflammatory response and resume the pre-injury activities. This systematic review aims to evaluate the safety and efficacy of intraarticular (IA) hyaluronic acid (HA) injection following ACLR.

MATERIAL AND METHODS

A literature search of electronic databases and a manual search of studies reporting clinical effectiveness of IA HA following ACLR was performed on 1^st November 2020. The quality of the methodology and risk of bias was assessed using the Cochrane Collaboration Risk of Bias Tool and Newcastle-Ottawa scale for randomized-controlled trial and prospective cohort studies, respectively.

RESULTS

Of 324 studies retrieved, four studies (3 RCTs and one prospective cohort study) were found to be suitable for inclusion in this review. These studies had a low to moderate risk of bias. There were 182 patients in the HA group and 121 patients in the control group. The demographic characteristics of the patients were similar in all studies. The pooled analysis of studies evaluating pain at different follow up periods (2-week, 4-6 weeks, 8-12 weeks) after ACLR revealed no significant difference between the HA and control groups (p > 0.05). The knee swelling was significantly less in the HA group at two weeks (MD -7.85, 95% CI: [-15.03, -0.68], p = 0.03, I2 = 0%), but no such difference was noted after 4-6 weeks and 8-12 weeks. The functional outcome score was not significantly different between the groups (SMD 0.00, 95% CI: 0.38 to 0.38, p = 0.99, I² = 0%).

CONCLUSIONS

Although the individual study demonstrated a short-term positive response regarding pain control and swelling reduction, the pooled analysis did not find any clinical benefit of IA HA injection following ACLR surgery.

LEVEL OF EVIDENCE

II.

Ultrasound-guided injection with hyaluronic acid in hip osteoarthritis: efficacy and safety in a real-life setting

BACKGROUND

For knee OA, EULAR has included hyaluronic acid (HA) intra-articular injection in the 2003 recommendations, making the intra-articular injection a sound therapeutic option. The ultrasound-guided intra-articular injections (USGIAI) have been demonstrated to be more efficient and safe in comparison to the blind procedure. Our objectives were to evaluate the short- and medium-term efficacy and safety of USGIAI of HA in moderate hip OA and patients' additional NSAIDs/pain killer intake.

PATIENTS AND METHODS

Patients with hip OA (KLG II/III), that failed standard of care therapy, received 3 consecutive HA-USGIAI (case group) while other patients (KLG II/III) treated according to current guidelines were chosen as a control group. Demographic data, comorbidities and medication intake were recorded. VAS pain scale and WOMAC score were performed at baseline and at 3 months. In the case group, they were additionally scored at 6 months. At baseline and at 6 months, hip X-ray assessment was also made. Ultrasound evaluation was made at each visit.

RESULTS

In the case group, 15 patients were enrolled and 28 hip joints were injected. The control group consisted of 17 hip OA patients. In the case group, pain evaluated by VAS score and WOMAC score were significantly and progressively decreased (p < 0.0001) from baseline up to 3 and 6 months, respectively. Indeed, the case group showed a significantly lower NSAIDs/pain killer median intake at 3 months from baseline (p < 0.05).

CONCLUSION

Our data suggest that HA-USGIAI may be an effective and safe treatment for moderate hip OA with short- and medium-term benefits. Key Points • US hip evaluation before interventional maneuvers may identify capsular distension suggestive for concomitant septic involvement, microcrystal arthropathy or incipient hip osteonecrosis. • USGIAI may be fundamental to achieve an efficacious and safe injection. • HA-USGIAI may be an effective and safe treatment for moderate hip OA with short- and medium-term benefits.

Improvement in condition specific and generic quality of life outcomes in patients with knee osteoarthritis following single intraarticular viscosupplementation injection

Background

Non-operative management of Osteoarthritis (OA) can be challenging. The intra-articular injection with hyaluronic acid (IAHA), corticosteroids and Platelet rich plasma are some of the popular modalities which are increasingly being employed as a stop-gap strategy before considering any surgical intervention for OA management. Among these, the intra-articular HA (IAHA) has been widely studied with variable and conflicting results.

Method

This was a prospective observational study conducted in adults with knee OA. Suitable patients were given IAHA (Synvisc-One®) on an out-patient basis. They were assessed in terms of VAS score, WOMAC score and SF36 scores at successive follow-up visits at 8, 24 and 52 weeks.

Results

50 patients were recruited in this study and followed for 52 weeks post injection of HA. Mean and SD values of VAS, WOMAC and SF36 scores were on a decreasing trend in each follow up visit. Percentage change between the visits was also statistically significant. The improvement in pain scores at successive visits was significant in KL grade 1 OA than grade 2 or 3 indicating strong association between them.

Conclusion

Short-term (up to one year) beneficial effects of intra-articular viscosupplementation with HA in early primary knee OA can be seen with a decreasing trend in the intensity of pain and an increasing trend in improving the physical functioning and health-related quality of life.

Hyaluronic Acid Therapy in Hip OA Does Not Perform Equally in Osteoarthritis Secondary to Juvenile Idiopathic Arthritis When Compared to Primary Osteoarthritis: A 2-Year Preliminary Evaluation

OBJECTIVE

Hip involvement in juvenile idiopathic arthritis (JIA) is one of most important causes of pain and disability. Total hip arthroplasty (THA) is considered the standard when medical approaches fail to relieve pain. However, THA is problematic for many reasons. As current literature lacks studies valuating medical management of osteoarthritis (OA) secondary to JIA, we assessed the long-term pain relief effect of US-guided intra-articular viscosupplementation in hip osteoarthritis secondary to JIA versus primary OA under different etiological conditions.

METHODS

Patients in both groups received intra-articular Hylan G-F 20 2 ml once a month for 3 consecutive months and every 6 months for 2 years as maintenance. Effectiveness (VAS and WOMAC), NSAID/analgesic consumption, tolerability, withdrawals and reason for discontinuation were collected at each time point. An inverse probability weighting was used to balance the two groups.

RESULTS

We retrospectively retrieved data of 14 JIA patients and 26 primary OA. Weighting successfully accounted for differences between the disease groups supporting the results. Viscosupplementation led to an early and significant improvement of pain and function and concomitant decrease in NSAIDs consumption, while the response diverged over 1 year with loss of benefits in JIA. The worst outcome was observed in active JIA.

CONCLUSIONS

Duration of symptom relief after intra-articular injection of hyaluronic acid depends on the nature of arthritis. Multiple courses of viscosupplementation are required to maintain low-dose NSAIDs consumption in patients responsive to treatment while shortening the time between consecutive injections might provide persistent positive results in patients suffering from JIA.

[Conservative treatment options for arthritis of the ankle : What is possible, what is effective?]

In this article the causes of arthritis in the region of the ankle are introduced and the conservative treatment options are described and discussed more extensively. The risks of treatment with nonopioid analgesics (NOPA) are presented in detail. The topical use of nonsteroidal anti-inflammatory drugs (NSAID) should always be considered in the clinical routine. If contraindications for oral NSAIDs are present, intra-articular treatment is a meaningful option. The best evidence is currently available for viscosupplementation but the study situation for the use of platelet-rich plasma (PRP) is still not sufficiently comprehensive and there are only a few case reports on the use of mesenchymal stem cells..

The efficacy of intraarticular viscosupplementation after arthroscopic partial meniscectomy: a randomized controlled trial

BACKGROUND

This study aimed to evaluate the efficacy of viscosupplementation after arthroscopic partial meniscectomy.

METHOD

A randomized controlled trial of 47 patients who underwent arthroscopic partial meniscectomy was conducted between March 2020 and March 2021. Patients were randomized into two groups: a viscosupplementation group (n = 23) and a control group (n = 24). A single-dose intraarticular hyaluronic acid injection was used as viscosupplementation. The 100 mm visual analogue scale (VAS) for pain assessment was measured at baseline and at 1 day, 2 weeks, 6 weeks, and 3 months post-surgery. The International Knee Documentation Committee (IKDC), Tegner, Lysholm, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores and range of motion (ROM) of the knee were measured at baseline, 2 weeks, 6 weeks, and 3 months.

RESULTS

The 100 mm VAS score for pain was significantly lower in the viscosupplementation group at 2 weeks post-surgery (27.5 mm vs. 40.7 mm, P = 0.047). ROM was significantly greater in the viscosupplementation group than in the control group at 2 weeks (131.5° vs. 121.0°, P = 0.044) post-surgery. No significant differences were observed in the IKDC or in the Tegner, Lysholm, and WOMAC scores between the two groups.

CONCLUSIONS

Viscosupplementation after arthroscopic partial meniscectomy significantly reduced pain at 2 weeks post-surgery and improved ROM of the knee at 2 weeks post-surgery. There might be some benefits in terms of pain and functional recovery of viscosupplementation after arthroscopic surgery.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

TRIAL REGISTRATION

This randomized controlled trial was registered at cris.nih.go.kr # KCT0004921 .

HYLAN G-F 20 VERSUS TRIAMCINOLONE IN THE TREATMENT OF PRIMARY SHOULDER OSTEOARTHRITIS. RANDOMIZED TRIAL

Introduction

The aim of this study was to evaluate the effect of using an intra-articular injection of hylan G-F 20 (HA group) on primary shoulder osteoarthritis compared with an intra-articular triamcinolone injection (T group).

Materials and Methods

The patients were randomized into 2 groups: in the HA group a single dose of intra-articular hylan G-F 20 was administered and in the T control group a dose of triamcinolone 20 mg was administered. The participants were evaluated at 1 week, 1, 3, and 6 months after the procedure. The patients were evaluated for pain, range of motion, Constant score, modified UCLA score, and SPADI.

Results

Seventy patients met the inclusion criteria and were randomized to the HA (38) and T (32) groups. Improvements in range of motion were significant (p > 0.05). We observed decreases in the general visual analog scale (VAS) for pain in both groups, especially in the cases of mild and moderate arthritis that received hyaluronic acid (mean values from 8.1 initially to 4.9 after 6 months) (p = 0).

Conclusions

Both injections led to a decrease in pain and an increase in patient satisfaction. The results tend to be better and longer lasting in patients receiving hyaluronic acid. Level of evidence II b; Cohort study.

Sodium hyaluronate-g-2-((N-(6-aminohexyl)-4-methoxyphenyl)sulfonamido)-N-hydroxyacetamide with enhanced affinity towards MMP12 catalytic domain to be used as visco-supplement with increased degradation resistance

The present paper describes the functionalization of sodium hyaluronate (NaHA) with a small molecule (2-((N-(6-aminohexyl)-4-methoxyphenyl)sulfonamido)-N-hydroxyacetamide) (MMPI) having proven inhibitory activity against membrane metalloproteins involved in inflammatory processes (i.e. MMP12). The obtained derivative (HA-MMPI) demonstrated an increased resistance to the in-vitro degradation by hyaluronidase, viscoelastic properties close to those of healthy human synovial fluid, cytocompatibility towards human chondrocytes and nanomolar affinity towards MMP 12. Thus, HA-MMPI can be considered a good candidate as viscosupplement in the treatment of knee osteoarticular disease.

Intra-articular Hymovis injection for managing hip OA in active sportsmen. A 24-month observational retrospective clinical investigation

BACKGROUND

Hip Osteoarthitis (OA) risk is sport-specific and depends on frequency, intensity, and type of mechanic stress the hip is subjected to. This retrospective observational study aims to investigate the safety and performance of Hymovis (HYADD-4) injection, a hexadecyl (C-16) HA-derivative, when used to manage symptomatic hip OA in active middle-aged sportsmen over a 24-month observation period.

METHODS

The retrospective analysis included clinical records of active sportsmen, aged between 40 and 65 years, and suffering from symptomatic Kellgren-Lawrence grade II to III hip OA, treated with two (24 mg/3 ml) Hymovis injections, two weeks apart, every 3-4 months, for two years. When available, data on MRI examination were included in the analysis as well as Heidelberg Sports Activity Score (HAS) and Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaires.

RESULTS

Thirty patients (56.4 ± 7.3 years) were included in the study, sixteen cyclists and 14 tennis players. For all patients, HAS and most HAGOS scores improved significantly (p < 0.05) at the first control visit (4 months) and further improved over time. For all other scores an important clinical benefit was experienced by more than 50% of participants. No adverse events were recorded.

CONCLUSION

Treatment of hip OA in active sportsmen with Hymovis seems a safe and effective approach for the management of OA symptoms, by potentially protecting cartilage and subchondral bone from further damage.

HPLC-UV Method Validation for Amobarbital and Pharmaceutical Stability Evaluation When Dispersed in a Hyaluronic Acid Hydrogel: A New Concept for Post-Traumatic Osteoarthritis Prevention

A mitochondrial electron transport chain member complex I inhibitor, amobarbital, can reduce oxidative damage and chondrocyte death, eventually preventing post-traumatic osteoarthritis (PTOA). Viscosupplementation using a crosslinked hyaluronic acid (HA) hydrogel is currently applied clinically for knee OA pain relief. In this work, we utilized the HA hydrogel as a drug delivery vehicle to improve the long-term efficacy of amobarbital. Here we evaluated the pharmaceutic stability of amobarbital when dispersed in a crosslinked HA hydrogel formulated in proportions intended for clinical use. We validated a high-performance liquid chromatography with an ultraviolet detector (HPLC-UV) method following International Conference for Harmonization Q2(R1) guidelines to ensure its suitability for amobarbital detection. The feasibility of this formulation's drug delivery capability was proven by measuring the release, solubility, and drug uniformity. The amobarbital/HA hydrogel showed comparable amobarbital stability in different biological fluids compared to amobarbital solution. In addition, the amobarbital/HA hydrogel imparted significantly greater drug stability when stored at 70°C for 24 hours. In conclusion, we confirmed the pharmaceutical stability of the amobarbital/HA hydrogel in various conditions and biological fluids using a validated HPLC-UV method. This data provides essential evidence in support of the use of this amobarbital/HA formulation in future clinical trials for PTOA treatment.

Safety and efficacy of single CHAP Hyaluronan injection versus three injections of linear Hyaluronan in pain relief for knee osteoarthritis: a prospective, 52-week follow-up, randomized, evaluator-blinded study

Background

The hyaluronic acid (HA) injections are widely used in knee osteoarthritis (OA) patients. We conducted the study comparing the efficacy and safety of single injection of Crosslinked Hyaluronic Acid Platform Hyaluronan (CHAP-HA) with 3-injection of linear hyaluronan in knee OA patients.

Methods

This was a randomized two-arms, evaluator-blinded, controlled, single-center study. Participants with knee OA received single CHAP-HA or three-injection of linear-HA. The 140 patients aged 35–85 years with radiographically confirmed knee OA were enrolled. At week 4, 12, 26, 39, and 52, visual analog scale (VAS) pain score, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, timed up and go (TUG) and subject’s adverse events (AE) of these 2 groups were recorded. Primary outcome of the differences of VAS pain score at week 26 between groups was analyzed with analysis of covariance (ANCOVA). At week 52, those who met the inclusion criteria could receive a CHAP-HA injection and being followed-up for the adverse events for 4 weeks.

Results

The trial was conducted from September 2015 to April 2017. A total 140 subjects were available for analysis (71 in the CHAP-HA group and 69 in the linear-HA group). At 26th week, there were significant more improvements in VAS pain scores in CHAP-HA compared with linear-HA. Both CHAP-HA and linear-HA showed significant improvements in the VAS pain score at week 26 compared with the baseline, and the occurrence of adverse events during the study period showed no between-group difference. In subjects with KL = 2, both groups showed significant improvements in VAS pain scores within 26 weeks. In patients with KL = 3, only CHAP-HA group showed significant improvement in VAS pain from 4 to 39 weeks. No unexpected or severe AEs were reported.

Conclusions

A single injection of CHAP-HA may be safe and more effective for 26 weeks in patients with knee OA by comparing to linear-HA; moreover, the pain relief effect of CHAP-HA may remain until 52 weeks. For patients with more severe OA, CHAP-HA was demonstrated to be more preferable to relieve OA pain. Furthermore, repeat treatment of CHAP-HA or using CHAP-HA after a three-injection HA was proved to be safe.

Trial registration

ClinicalTrials.gov: NCT03643588. Date: August 23, 2018 (retrospectively registered).

Level of Evidence: Therapeutic Level I.

Clinical effectiveness and safety of intra-articular injection of HYALGO in the management of knee osteoarthritis symptoms: A multicenter prospective study

BACKGROUND

The reduced concentration of hyaluronic acid in the synovial fluid, leading to impairment of joint function and painful symptomatology during knee osteoarthritis (OA), can be restored by using injectable formulations of hyaluronic acid (HA) and chondroitin sulfate (CS), variable for relative composition, HA/CS molecular modifications, and injection protocols. The present study aims to assess the safety and performance of the intra-articular (IA) viscosupplementing agent HYALGO, a formulation combining 40 mg/mL HA (>1700 kDa) and 40 mg/mL CS, in the treatment of patients suffering from knee OA.

METHODS

74 patients affected by knee lesions classified as grade II and III according to Kellgren and Lawrence classification were prospectively recruited and treated with three HYALGO injections (2 mL) given one week apart. Visual analogue scale (VAS) pain changes were monitored at each injection and over-time at 6, 14, and 26 weeks of follow-up. Secondary endpoints were: Western Ontario McMaster University Osteoarthritis index (WOMAC), Patient's Global Assessment (PGA) score, Clinical Observer Global Assessment (COGA) score, Outcome Measures in Rheumatology Committee (OMERACT) and Osteoarthritis Research Society International (OARSI) responders rates. Patients were also assessed for changes in their ultrasound joint scores according to the criteria of the OMERACT US Task Force Group.

RESULTS

Pain reduction was statistically significant starting from the first IA injection. Mean pain reduction from baseline to week 26 was -90.6%. At 26 weeks, WOMAC Pain was reduced by -62.7%, WOMAC Stiffness by -47.2%, WOMAC Physical Function by -54.1%; Total WOMAC by -53.8%. The VAS PGA change from baseline was -48.0 [mm] and VAS COGA -41.0 [mm]. Responders at week 26 were 78.4%. Ultrasound parameters (joint effusion, synovial thickness, and popliteal cysts) improved or remained stable from baseline to week 6.

CONCLUSIONS

Three injections of HYALGO were safe and effective to manage symptomatic knee OA, with a beneficial effect that increased progressively over time, peaking 6 months after injection.

The effect of viscosupplementation on early-stage knee osteoarthritis: Clinical evaluation and assessment of cartilage in vivo with 7 T MRI

INTRODUCTION

Viscosupplementation is a well-known strategy for managing early stages knee Osteoarthritis. However, despite its effectiveness in reducing symptoms, it has not yet been found to have an effect on joint cartilage. The aim of this study is to evaluate the clinical efficacy of a new product with gel-like behaviour and its in vivo effects on joint cartilage.

METHODS

20 patients were treated by 2 consecutive injections of hyaluronan derivative Hymovis® at one-week interval. Clinical evaluation was performed before the treatment and at each time point during the follow-up using WOMAC and VAS. A 7 T magnet was used for cartilage evaluation at each MRI time point: T2 Relaxation Time (RT), T2∗ RT and cartilage parameters were evaluated before the first injection, after 45 days and at 6 months follow-up. Statistical analysis was obtained for each reported data.

RESULTS

We report significantly reduction in symptoms with an increase in knee and global activity functions. The T2 RT for lateral tibial compartment and T2∗ RT for Patello-Femoral compartment significantly decreased. A T2 RT reduction was observed in all knee compartments except for the medial tibial one, while a T2∗ RT reduction was observed in all knee compartments. We report an increase in cartilage volume and thickness in most of patients with a reduction of cartilage defects in 9 patients, but we didn't find MRI signals clearly referable to cartilage regeneration.

CONCLUSIONS

MRI results have confirmed the possibility to employ 7T magnets to evaluate early changes in cartilage structure in vivo. HA VS has provided good clinical outcomes and an improvement in the global assessment of the knee joint, but it doesn't seem to significantly modify the cartilage over the time.

Osteoarthritis of the shoulder in under-50 year-olds: A multicenter retrospective study of 273 shoulders by the French Society for Shoulder and Elbow (SOFEC)

INTRODUCTION

Osteoarthritis (OA) of the shoulder in under-50 year-olds is rare, and treatment is delicate. Shoulder replacement incurs frequent long-term risk of progression and a high revision rate, making it unsuited to young active patients. The aim of the present study was to determine the epidemiology of shoulder OA in under-50 year-olds and to assess the clinical results of the various treatment options.

HYPOTHESIS

The main study hypothesis was that well-conducted non-operative treatment can allow shoulder replacement to be postponed. The secondary hypothesis was that anatomic total shoulder arthroplasty (TSA) is the treatment of choice when other options fail.

MATERIALS AND METHODS

A multicenter retrospective study included primary (POA) and post-instability osteoarthritis (PIOA) in patients aged≤50years at symptom onset. Exclusion criteria comprised post-traumatic OA, rheumatoid arthritis and necrosis. Two hundred and sixty-six patients for 273 shoulders were included from 13 shoulder surgery centers: 2 types of non-operative treatment (28 by platelet-rich plasma [PRP] and 88 by viscosupplementation), 73 arthroscopies, and 150 implantations (62 humeral hemiarthroplasties [HA], comprising 10 hemi-metal, 24 hemi-pyrocarbon and 28 hemi-resurfacing; 77 anatomic total prostheses, and 11 reverse prostheses). Minimum follow-up was 12 months for non-operative treatment and 24 months for arthroplasty (some patients having both). Endpoints comprised Constant score, Subjective Shoulder Value (SSV) and number of complications/revision procedures.

RESULTS

Mean age at treatment was 43 years (range, 23-65 years), with 75% male predominance. Symptom onset was earlier in PIOA than in POA: 36 vs. 39 years (range, 20-50 years). PRP and viscosupplementation postponed implantation by a mean 3.5 years in 86% of cases, as did arthroscopy in 56%. ER1 restriction was the most negative factor. At 74 months' follow-up for HA and 95 months for TSA, mean Constant score was significantly lower for HA (56 vs. 67; p=0.004), with higher rates of complications (31% vs. 11%) and implant exchange (13% vs. 9%).

DISCUSSION/CONCLUSION

PRP, viscosupplementation and arthroscopy allow implantation to be postponed until the shoulder becomes stiff and painful. In case of failure, TSA is the most effective solution in the medium-term.

LEVEL OF EVIDENCE

IV a; therapeutic study - investigating the results of treatment.

Effects of low and high molecular weight hyaluronic acid on the osteoarthritic temporomandibular joint in rabbit

OBJECTIVE

To compare the effect between intra-articular infiltration of low molecular weight (LMW-HA) and high molecular weight hyaluronic acid (HMW-HA) on the histopathological characteristics of the cartilage and disc of the temporomandibular joint (TMJ) osteoarthritis (OA) induced in rabbits.

MATERIAL AND METHODS

An experimental study was conducted on 38 rabbit TMJs. The effect of different hyaluronic acids was compared at 30 and 135 days. Histopathological analysis was performed. Cartilage damage was assessed with the OARSI scale.

RESULTS

The severity of the induced OA according to OARSI was 3.4 degrees in the mandibular condyle (MC) and 3.2 in the mandibular fossa (MF); the articular disc (AD) presented disorganization of the collagen fibers, with randomly arranged hypertrophic chondrocytes. At 30 days, untreated TMJs worsened. TMJ treated with LMW-HA reduced its severity to 1.5 degrees in MC and 1.6 in MF, the AD presented histological aspects within normal limits. TMJ treated with HMW-HA presented 2.4 degrees in MC and 2.2 in MF, the AD maintained characteristics similar to the group with OA. At 135 days, all groups worsened.

CONCLUSION

Exogenous HA is effective in the management of TMJ-OA induced in rabbits, showing cartilage and articular disc repair at 30 days. The LMW-HA group had better effects on joint tissue than HMW-HA 30 days after treatment. However, at 135 days, both groups presented regression of joint tissue repair.

CLINICAL RELEVANCE

HA is effective in the anti-arthritic treatment of TMJ-OA induced in rabbits; LMW-HA shows better results in cartilage and articular disc repair than HMW-HA.

IMPROVEMENTS IN HIP OSTEOARTHRITIS WITH LAVAGE, TRIAMCINOLONE AND HYLAN G-F20

Objective:

To verify whether the use of Hylan G-F20 improves saline lavage and triamcinolone injection results in the treatment of hip osteoarthritis (HOA).

Methods:

82 patients with HOA categorized as grades II and III severity, according to Kellgren and Lawrence criteria, were randomized into the groups: lavage and triamcinolone (G0); lavage, triamcinolone, and 2 mL of hylan G-F20 (G1); lavage, triamcinolone, and 4mL of hylan G-F20 (G2); lavage, triamcinolone, and 6mL of hylan G-F20 (G3). The VAS, range of motion (ROM), WOMAC, and Lequesne questionnaires were administered at baseline, one, three, six, and twelve months post-injection.

Results:

All groups showed clinically relevant improvements (> 20%) between baseline and first month post-injection, maintaining subjective results throughout the study period (p < 0.001). We found no differences between groups in any subjective evaluations (p > 0.05, for all). G2 and G3 obtained improved flexion results up to a year (p = 0.028). Hylan groups presented an improved external rotation since the first postoperative month and maintained the results up to a year (G1, p = 0.041; G2, p = 0.007), whereas G0 showed no improvement (p = 0.336).

Conclusion:

Hip lavage and triamcinolone injection, with or without the use of hylan, improves pain, function, and quality of life up to a year in HOA. Hylan may improve ROM up to one year. Level of Evidence IB, Randomized clinical trial.

Viscosupplementation for hip osteoarthritis: Does systematic review of patient-reported outcome measures support use?

INTRODUCTION

Osteoarthritis of the hip is one of the leading causes of disability worldwide. There is lack of agreement among providers and governing agencies regarding the efficacy of hyaluronic acid (HA) for the management of hip osteoarthritis (OA). Therefore, the purpose of this systematic review was to determine how HA administration impacts 1) patient reported outcome measures (PROMs) and 2) rates of conversion to THA.

METHODS

The PubMed, EBSCO host, and Google Scholar electronic databases were queried for all studies published between January 1st, 2000 and January 1st, 2020 that reported on outcomes following HA administration for treatment of hip OA. The following keywords were implemented with AND and OR Boolean operators: "hip"; "osteoarthritis"; "arthritis"; "viscosupplementation"; "hyaluronic acid." Our final analysis included 39 studies and reported on a total of 5,864 patients receiving injections of HA.

RESULTS

All studies reporting on visual analog scale (VAS), patient global assessment, and total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores demonstrated improvements following HA administration. For the Lequesne Index (LI), WOMAC pain, WOMAC function, and Harris Hip Score (HHS) values, a majority of studies reported that HA would prove beneficial, with one analysis suggesting a lack of improvement. There was inconsistent evidence across studies regarding the effectiveness of HA compared to other intra-articular injections. The formulation of the administered viscosupplementation did not appear to influence outcomes. Furthermore, rates of conversion to THA were relatively low when evaluating 1- to 4-year follow-up intervals.

DISCUSSION

Non-comparative studies consistently demonstrated that HA can achieve satisfactory pain reduction and functional improvement. However, there was not enough evidence in the current literature regarding whether HA is superior to placebo or other types of intra-articular injections. Future studies should continue to compare HA to other treatment modalities in randomized controlled trials with larger sample sizes.

Minimally Invasive Therapies for Osteoarthritic Hip Pain: a Comprehensive Review

PURPOSE OF REVIEW

Osteoarthritis (OA) is a highly prevalent cause of chronic hip pain, affecting 27% of adults aged over 45 years and 42% of adults aged over 75 years. Though OA has traditionally been described as a disorder of "wear-and-tear," recent studies have expanded on this understanding to include a possible inflammatory etiology as well, damage to articular cartilage produces debris in the joint that is phagocytosed by synovial cells which leads to inflammation.

RECENT FINDINGS

Patients with OA of the hip frequently have decreased quality of life due to pain and limited mobility though additional comorbidities of diabetes, cardiovascular disease, poor sleep quality, and obesity have been correlated. Initial treatment with conservative medical management can provide effective symptomatic relief. Physical therapy and exercise are important components of a multimodal approach to osteoarthritic hip pain. Patients with persistent pain may benefit from minimally invasive therapeutic approaches prior to consideration of undergoing total hip arthroplasty. The objective of this review is to provide an update of current minimally invasive therapies for the treatment of pain stemming from hip osteoarthritis; these include intra-articular injection of medication, regenerative therapies, and radiofrequency ablation.

Viscosupplementation may preserve tibial cartilage and collagen in osteoarthritis: findings from a preclinical model of osteoarthritis

PURPOSE

Intraarticular (IA) hyaluronic acid (HA) injection is used to reduce pain and improve mobility in knee osteoarthritis (OA). Little is known about histopathological changes underlying HA efficacy. This study investigated dose-related effects of 1% sodium hyaluronate (BioHA) on knee joint histopathology and pain responses in a medial meniscal tear (MMT) rat model of OA.

METHODS

Following MMT surgery, rats were randomized into treatment groups: single IA injection of vehicle, BioHA, or an avian-derived hyaluronic acid (hylan G-F 20) on Day 7; or 3 weekly injections of vehicle or BioHA on Days 7, 14, and 21. On Day 35, joints were evaluated by microscopic histopathology for cartilage degeneration, collagen degeneration, synovitis, and cytokine expression (tumor necrosis factor α, transforming growth factor β).

RESULTS

Joint pathology for control animals was consistent with that expected for the MMT model. Rats treated with 3 injections of IA-BioHA had significantly reduced collagen degeneration (21%) relative to control animals. No significant change in collagen degeneration was observed for rats given a single injection of hylan G-F 20 or IA-BioHA compared to control animals. HA treatment did not affect cytokine expression.

CONCLUSIONS

IA-BioHA viscosupplementation in a rat MMT model of OA showed preservation of joint cartilage and collagen. This effect was most pronounced on tibial surfaces having less severe injury, suggesting that treatment should be initiated early in the disease process. A comparison of responses to IA-BioHA or hylan G-F 20 in the MMT rat OA model suggest IA-BioHA may be more effective in preserving joint connective tissue.

Hylan G-F20 and galactomannan joint flares are associated to acute synovitis and release of inflammatory cytokines

BACKGROUND

Injection of Hylan G-F20 (HY) into joints may provoke local flares, which mechanisms may involve reaction to protein contaminants. We have previously developed a protein-free saline-soluble galactomannan derived from guar gum (GM) that displays both analgesia and chondroprotection in experimental osteoarthritis (OA). We now demonstrate that both GM and Hylan G-F20 (HY) promote mild synovitis with cytokine release after intra-articular injection.

METHODS

Mice received 100 μg/25 μL GM or HY or saline into the knees. Joint pain was evaluated using von Frey test; cell influx, interleukin (IL)-1, IL-6, and CXCL-1 (pg/mL) levels were assessed in joint lavage at 6 h. Synovia were excised for histopathology.

RESULTS

Neither GM nor HY after being given into mice knee joints induced pain albeit promoting mild cell influx into joint washings as well as mild synovitis at histology, with no damage to the underlying cartilage. HY but not GM promoted IL-1 release into mice joints. Both compounds induced IL-6 and CXCL-1 release.

CONCLUSION

Intra-articular injection of HY or GM promote acute transient synovitis whilst not provoking detectable significant joint damage. Local administration of these polysaccharides induces acute intra-articular release of inflammatory cytokines, which may account for joint flares following viscosupplementation.

Hyaluronic Acid Injections in the Treatment of Osteoarthritis Secondary to Primary Inflammatory Rheumatic Diseases: A Systematic Review and Qualitative Synthesis

The purpose of this study is to review the current literature on the use of hyaluronic acid (HA) specifically applied to the treatment of osteoarthritis (OA) secondary to primary inflammatory rheumatic diseases. Osteoarthritis should be carefully considered because it has potentially devastating effects on health-related quality of life. Locally injected HA seems to be an effective treatment for OA but it is not clear how to place this treatment in the context of inflammatory rheumatic disorders. To retrieve relevant articles, we conducted the search through MEDLINE, EMBASE and Cochrane Databases performing the PICO strategy. We finally selected four randomized clinical trials and six observational studies and grouped them in accordance with its main objective within three focuses: the clinical effect of HA therapy in joints without any signs of inflammation, the clinical effects of HA therapy in joints with active synovitis, and the involvement and changes of synovial fluid in the treatment of secondary OA. Our qualitative analysis clearly showed that the current literature is marked by high levels of heterogeneity and therefore difficult to interpret. Therefore, our hypothesis that viscosupplementation should be considered as a treatment for chronic moderate symptomatic OA secondary to inflammatory rheumatic diseases, and not for flares with joint swelling, cannot be definitely supported. Well-designed studies are necessary to definitively clarify the range of application of intra-articular HA injections in the treatment of inflammatory rheumatic disorders.

What is the Evidence of Hyaluronic Acid and Polyacrylamide Hydrogel in Intra-articular Therapy in Equines? Systematic Literature Review

A systematic review was conducted to investigate evidence to support or refute the use of hyaluronic acid and polyacrylamide hydrogel as intra-articular therapy in equines, which are frequent treatment options in the routine of veterinarians of equines in cases of osteoarthritis. In total, 19 studies were included, among clinical and in vitro studies, as well as a retrospective series of cases. The outcomes of the included studies provided fragile evidence supporting the recommendation for intra-articular use of hyaluronic acid. No study was included showing any clinical outcome in diseased synovial tissues of the polyacrylamide hydrogel. There is no concrete evidence of benefits, treatment protocols, and mechanisms of action of hyaluronic acid in the joint therapy in equines.

Impact of obesity, structural severity and their combination on the efficacy of viscosupplementation in patients with knee osteoarthritis

Background

Obesity and radiological severity have been identified to be independent predictors of a low rate of response to viscosupplementation (VS), in patients with knee osteoarthritis (OA). Is that enough to formally refute VS in such patients in whom surgery is sometimes contraindicated?

Objectives

To compare pain and function scores before and 6 months after knee VS, according to the weight status (obese versus non obese), the radiological severity (mild/moderate versus severe) and both combined.

Methods

Post-hoc analysis of a prospective, double blind, randomized, multicentre trial, comparing 2 viscosupplements, in patients with symptomatic knee OA. Patients were classified according to body mass index (BMI < or ≥ 30 kg.^− 2), OARSI radiological grade (1–2 versus 3) and OMERACT-OARSI response criteria (Yes/No). WOMAC between-group comparisons (obese versus non-obese, OARSI 1–2 versus 3, and both combined) in all patients and in OMERACT-OARSI Responders, were achieved using Mannn-Whitney U test.

Results

One-hundred and sixty-six patients were analyzed: 28.3% were obese, 44% were OARSI grade 3, 42,2% were neither obese nor OARSI 3, whereas 14.5% were obese and OARSI 3. At baseline WOMAC pain score did not differ according to the patients sub-groups (p > 0.05). Six months after VS, WOMAC pain decreased significantly in all patient sub-groups (all p < 0.01). At month 6, WOMAC pain sub-score was significantly lower in non-obese than in obese patients (4.9 ± 4.1 versus 7.1 ± 4.9; p = 0.008) and in patients OARSI 1–2 versus 3 (4.8 ± 4.3 versus 6.4 ± 4.5; p = 0.009). However, in responder patients there was no difference in pain score and pain decrease related to the weight status and the radiological score.

Conclusion

These results do not confirm our previous conclusions that recommended not performing VS in obese patients with severe knee OA. Although the chances of being a responder were much reduced in these patients, the benefit of patients who respond to treatment was similar to that of subjects with normal weight and mild/moderate OA. Different pain phenotypes, more than overweight and advanced disease, might be the main reason for the success or failure of VS.

BRAZILIAN CONSENSUS STATEMENT ON VISCOSUPPLEMENTATION OF THE KNEE (COBRAVI)

Objective:

The aim of this consensus statement on viscosupplementation is to serve as a reference document based on relevant literature and clinical experience in the treatment of knee osteoarthritis using an intra-articular injection of hyaluronic acid, covering key aspects such as clinical indications, effectiveness, and tolerability.

Methods:

A multidisciplinary panel including two sports medicine physicians, six orthopedists, four physiatrists, and two rheumatologists were selected based on their clinical and academic experience of viscosupplementation. Sixteen statements were prepared and discussed, after which a vote was held. Each member of the panel gave a score between 0 and 10 on a Likert scale, specifying their level of agreement with the statement.

Results:

The panel reached a consensus on several issues. Specifically, the panel agreed that the best indication is for mild to moderate knee arthrosis; prior or concomitant use of intraarticular triamcinolone hexacetonide may optimize the effect of hyaluronic acid; viscosupplementation should not be performed as an isolated procedure but in conjunction with other rehabilitative and pharmacological measures; viscosupplementation has analgesic, anti-inflammatory, and chondroprotective effects; and viscosupplementation is cost-effective.

Conclusion:

This consensus statement provides clear information and guidance for both individuals and payers. Level of evidence V, Consensus statement.

Halting hyaluronidase activity with hyaluronan-based nanohydrogels: development of versatile injectable formulations

Hyaluronan (HA) is among the most used biopolymers for viscosupplementation and dermocosmetics. However, the current injectable HA-based formulations present relevant limitations: I) unmodified HA is quickly degraded by endogenous hyaluronidases (HAase), resulting in short lasting properties; II) cross-linked HA, although shows enhanced stability against HAase, often contains toxic chemical cross-linkers. As such, herein, we present biocompatible self-assembled hyaluronan-cholesterol nanohydrogels (HA-CH NHs) able to bind to HAase and inhibit the enzyme activity in vitro, more efficiently than currently marketed HA-based cross-linked formulations (e.g. Jonexa™). HA-CH NHs inhibit HAase through a mixed mechanism, by which NHs bind to HAase with an affinity constant 7-fold higher than that of native HA. Similar NHs, based on gellan-CH, evidenced no binding to HAase, neither inhibition of the enzyme activity, suggesting this effect might be due to the specific binding of HA-CH to the active site of the enzyme. Therefore, HA-CH NHs were engineered into injectable hybrid HA mixtures or physical hydrogels, able to halt the enzymatic degradation of HA.

Towards reaching consensus on hyaluronic acid efficacy in knee osteoarthritis

Intra-articular injection of hyaluronic acid (HA) is a controversial treatment for knee osteoarthritis (OA). While clinical efficacy of HA relative to saline injections has been demonstrated in many studies, these results are of limited value in real-world clinical practice since saline injection is not a knee OA treatment. Instead, rigorous postmarket comparative studies of HA versus approved knee OA treatments are encouraged. The conduct of such studies is particularly important given the paucity and heterogeneous nature of current evidence regarding nonsurgical knee OA treatment. KEY POINTS: • Societal guidelines recommend nonsteroidal anti-inflammatory drugs and corticosteroid injections, but not hyaluronic acid injections, for knee osteoarthritis (OA) despite inconsistent supportive data. • This article encourages rigorous comparative post-approval studies to clarify the role of nonsurgical treatments used in clinical practice for knee OA.

[Efficacy of viscosupplementation with high and medium molecular weight hyaluronic acid in patients with symptomatic gonarthrosis grades II-III]

INTRODUCTION

OA is currently the fifth leading cause of adult disability, its prevalence increases from age 40. Viscosupplementation is a treatment for the early stages of knee OA.

OBJECTIVE

To compare efficacy and quality of life in patients with symptomatic gonartrosis, treated with high and low molecular weight hyaluronic acid.

MATERIAL AND METHODS

Analytical, retrospective, cross-sectional, observational study of clinical records of patients diagnosed with grade II and grade III gonarthrosis, October 2017 to June 2018, treated with viscosupplementation with high molecular weight hyaluronic acid or low molecular weight; WOMAC quality of life and scale were analyzed prior to the first application and tracked at two, four and six months.

RESULTS

194 patients, aged between 30 to 87 years (promedio 61.85; SD = 11.3); 134 women (69.1%), 60 men (30.9%). In both groups the evolution was towards improvement, with a decrease in the WOMAC score, with no significant difference between groups. The WOMAC score had a minimum increase after 6 months of application in both groups, which is interpreted as decreasing the therapeutic effect. Two patients had localized minimal adverse reactions which were resolved with general measures.

CONCLUSION

Hyaluronic acid in both presentations, high and low molecular weight, are effective in the treatment of symptomatic goonarthrosis without difference to molecular weight.

Gait analysis following single-shot hyaluronic acid supplementation: a pilot randomized double-blinded controlled trial

Objectives

Viscosupplementation with new-generation, polyol-containing, cross-linked hyaluronic acid (HA) gels reduces joint inflammation in patients with knee osteoarthritis. Gait analysis is a complementary outcome measure to standard patient-reported scores and physical measures for testing the effect of HA injection. This three-arm, prospective, randomized, controlled, double-blind, feasibility pilot study investigated which gait parameters are more sensitive following a single bolus injection of polyol-containing HA for knee osteoarthritis.

Methods

Twenty-two patients with Ahlbäck grade II-III knee osteoarthritis were randomly allocated into three groups: (1) HA + mannitol (n = 9), (2) HA + sorbitol (n = 5), and (3) saline placebo (n = 8). Patients were assessed by blinded observers prior to injection and at 4 weeks post-injection (4W). Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society score (KSS), EuroQol in five-dimensions (EQ-5D), VAS pain, and VAS stiffness. Gait was assessed over 30 m using a portable inertial-based data logger (Physilog®).

Results

Differences between 4W and baseline were statistically significant for the mannitol-containing viscosupplement, with a median increase of 0.076 m/s on gait speed (p = 0.039), 0.055 m on stride length (p = 0.027), and 15 points on the KSS (p = 0.047). In contrast, the HA + sorbitol and saline groups demonstrated no significant changes from baseline to 4W in any gait parameters or self-reported outcome measures (all p > 0.3). The observed increase in gait speed is approximately 13% greater than the mean difference between healthy subjects and those with knee osteoarthritis, is clinically important, and thus is a sensitive gait parameter.

Conclusions

This study demonstrated gait speed and stride length are the most relevant gait parameters to investigate when assessing the effect of polyol-containing HA viscosupplementation. This study supports the need for a larger, randomized, controlled, clinical trial to assess the effect of a single-bolus HA injection versus multiple injections in people with knee osteoarthritis using both gait performance and self-reported parameters of knee function.

Trial registration

This study was retrospectively registered at clinicaltrials.gov on August 20, 2018, and assigned #NCT03636971.

Level of evidence

I.

Corticosteroids and Hyaluronic Acid Injections

Osteoarthritis is a common condition that affects many individuals resulting in pain, reduced mobility, and decreased function. Corticosteroids have been a mainstay of osteoarthritis treatment. Studies have shown that they provide short-term pain improvement and can be used for osteoarthritis flares. Hyaluronic acid injections have extensively been studied in knee osteoarthritis but to a lesser degree in other joints. Despite some debate between societies, a large number of recent studies have shown hyaluronic acid to be a viable treatment option showing longer-term improvement in both pain and function.

Efficacy of viscosupplementation with hyaluronic acid in temporomandibular disorders: A systematic review

OBJECTIVE

To perform a systematic review of the viscosupplementation effectiveness with hyaluronic acid (HA) in the articular Temporomandibular Dysfunctions (TMDs) clinical management.

METHOD

Electronic searches were performed in the following databases: MEDLINE (via PubMed), Scopus, Web of Science, Cochrane Library, EMBASE, LILACS, BBO, SIGLE (System for Information on Grey Literature in Europe), ClinicalTrials.gov, and the Brazilian Clinical Trials Registry (ReBec). Only randomized clinical trials that evaluated the intra-articular administration of HA or its derivatives in osteoarthritis and/or anterior displacement of the temporomandibular joint (TMJ) disc were included. The primary outcomes evaluated were patients' self-report of pain and/or discomfort in the TMJ. Each study was assessed for the risk of bias, using the Cochrane collaboration's risk of bias tool.

RESULTS

A total of 640 studies were obtained in the electronic search. After the application of the eligibility criteria, manual search, and duplicate removal, 21 articles were included. Five articles classified their volunteers with internal derangements of the TMJ, in 4 articles the treatment was directed to participants with disc displacement with reduction and the other articles evaluated HA therapy in osteoarthritis. The protocols presented heterogeneity, varying in the form of application, associated or not with arthrocentesis, number of applications, molecular weight, dose and concentration. Nine studies presented high risk of bias.

CONCLUSION

Due to the heterogeneity and methodological inconsistencies of the studies evaluated, it was not possible to establish the efficacy of HA in articular TMDs.

Current Concepts and Future Directions of Minimally Invasive Treatment for Knee Pain

PURPOSE OF REVIEW

The purpose of this paper is to review the percutaneous interventions available for the treatment of osteoarthrosis of the knee that address pain and prolong the time to arthroplasty.

RECENT FINDINGS

Corticosteroid injection and viscosupplementation have been the most studied, but there is still no consensus about their value. Thermal nerve ablation, including both radiofrequency ablation and cryoneurolysis, is a promising new modality of therapy that may increase in clinical use given current data showing favorable outcomes. Of the future therapies that are currently under investigation, synovial embolization via the geniculate arteries represents an exciting new approach that may soon be available clinically. There are various percutaneous interventions available for the treatment of osteoarthrosis of the knee that address pain and prolong the time to arthroplasty.

A Comparison Between Rheological Properties of Intra-articular Hyaluronic Acid Preparations and Reported Human Synovial Fluid

Introduction

This study aims to compare the properties of currently available intra-articular hyaluronate (IA-HA) products widely available in the USA to those of healthy knee synovial fluid with respect to their bulk rheological properties. We hypothesize that products would have differing rheological properties, with some more closely resembling the properties and physiological aspects of healthy joint fluid HA.

Methods

We obtained reported HA product molecular weights, as well as measurements of the presence of cross-linking, zero shear rate viscosity, shear thinning ratio, and crossover frequency for the following IA-HA products available in the USA: Euflexxa^®, Orthovisc^®, Supartz^®, Monovisc^®, Synvisc^®, Synvisc-One^®, Gel-One^®, and Hyalgan^®.

Results

Differences were seen between the study products across all of the investigated parameters. Hyalgan, Supartz, Orthovisc, and Euflexxa had a linear chain structure, while Synvisc, Synvisc-One, and Monovisc were cross-linked in structure. Molecular weight, shear rates, and crossover frequencies ranged widely across tested products, with values ranging from below to above those reported for healthy knee synovial fluid HA. When compared to healthy knee parameter values reported within the current literature, observed parameters for Euflexxa and Orthovisc were typically seen to be the most similar to healthy knee synovial fluid. When comparing Euflexxa and Orthovisc directly, Euflexxa was more often similar to the properties of healthy knee synovial fluid with respect to the observed parameters of molecular structure, shear rates, and crossover frequency.

Conclusion

Available IA-HA products vary with respect to molecular weight, presence of cross-linking, shear rate dependency of viscosity, and crossover frequency. Since IA-HA treatment for osteoarthritis aims to restore synovial fluid back to original HA property characteristics, using HA supplements resembling healthy synovial fluid is a logical approach. Our findings demonstrate that Euflexxa is the most similar to healthy synovial fluid with respect to molecular structure, shear rates, and crossover frequency.

Funding

Ferring Pharmaceuticals, Inc.

Hyaluronic acid injections for osteoarthritis of the knee: predictors of successful treatment

PURPOSE

This study aimed to identify patient and treatment factors that predict a favourable response to intra-articular hyaluronic acid (HA) treatment to better guide patient and treatment selection.

METHODS

This prospective, observational study evaluated patients with mild-to-moderate (Kellgren-Lawrence grades 1-3) primary knee osteoarthritis treated between March 2013 and May 2016. Patient function and pain scores were assessed by the Western Ontario and McMaster Universities Arthritis Index/Knee Injury and Osteoarthritis Outcome Score (WOMAC/KOOS) and visual analogue scale (VAS) surveys, with response to treatment defined according to the Osteoarthritis Research Society International (OARSI) 2004 criteria. Surveys were completed at each injection and three months post-treatment. Patients were followed an average of 27 months.

RESULTS

Of 102 patients, 57% had a positive response. Those at least twice as likely to respond were patients with grades 1-2 osteoarthritis or a positive response to the first injection and those who were ≥60 years. Gender, race, body mass index (BMI), smoking status, HA brand, and initial VAS and WOMAC/KOOS scores were not significant predictors of success. Mean time to arthroplasty following injection series was 11 months (30% of nonresponders, 12% of responders). The VAS strongly correlated with KOOS pain scores and successful outcomes.

CONCLUSION

Patients with mild-to-moderate osteoarthritis (grades 1-2) and those responding positively to the first injection were twice as likely to respond positively to the injection series, as were patients ≥60 years. Patients who did not respond positively were more likely to proceed to arthroplasty. The VAS appears to be a reliable method of defining and monitoring treatment success. Judicious patient selection and counseling may improve outcomes associated with intra-articular HA injections.

Effects of a viscosupplementation therapy on rabbit menisci in an anterior cruciate ligament transection model of osteoarthritis

The aim of this study was to evaluate the morphological, microstructural, and mechanical effects of a viscosupplementation therapy on rabbit menisci at an early stage of osteoarthritis (OA). Anterior cruciate ligament transection (ACLT) was performed in twelve male New-Zealand White rabbits on the right knee joint. Six of these twelve rabbits received a mono intra-articular injection of high molecular weight hyaluronic acid (HA) two weeks after ACLT. Six additional healthy rabbits served as controls. Medial menisci were removed from all right knees (n=18) six weeks after ACLT and were graded macroscopically. Indentation-relaxation tests were performed in the anterior and posterior regions of the menisci. Collagen fiber organization and glycosaminoglycan (GAG) content were assessed by biphotonic confocal microscopy and histology, respectively. Viscosupplementation significantly (p=0.002) improved the surface integrity of the medial menisci compared to the operated non-treated group. Moreover, the injection seems to have an effect on the GAG distribution in the anterior region of the menisci. However, the viscoelastic properties of both operated groups were similar and significantly lower than those of the healthy group, which was explained by their modified collagen fiber organization. They displayed disruption of the tie fibers due to structural alterations of the superficial layers from which they emanate, leading to modifications in the deep zone. To conclude, the viscosupplementation therapy prevents macroscopic lesions of the menisci, but it fails to restore their collagen fiber organization and their viscoelastic properties. This finding supports the role of this treatment in improving the lubrication over the knee.

Hylan GF-20 Viscosupplementation in the Treatment of Symptomatic Osteoarthritis of the Knee: Clinical Effect Survivorship at 5 Years

Purpose

Controversies remain surrounding the choice of hyaluronic acid products and patient selection. A study was conducted to report the long-term survivorship of intra-articular injection effect of high molecular weight hyaluronic preparation hylan GF-20 (Synvisc-One) for patients with symptomatic knee osteoarthritis.

Materials and Methods

A retrospective observational analysis of a single therapeutic series was carried out. The analysis was conducted to determine therapeutic effect survivorship taking arthroplasty and any other surgical interventions as endpoint results.

Results

Seventy-seven consecutive patients (82 knees) were followed up for five years. At one-year follow-up, 71 knees (87%) responded to treatment and only 8 knees (10%) were offered arthroplasty due to persistence of symptoms. At five-year follow-up, 41 (50%) were still considered responders. During the study period, repeat injection was given in 9 knees (11%). Arthroplasty (either total or unicompartmental) was required in 26 (31%). Kaplan-Meier survivorship analysis of therapeutic effect demonstrated 67% survival at 5 years with arthroplasty as endpoint and 58% survival at 5 years with all secondary interventions as endpoint.

Conclusions

This study demonstrates a significantly longer duration of clinical benefit of hylan GF-20 injection. Present results may suggest a notion of an ideal delay therapeutic strategy for patients not ready to receive an arthroplasty. Further studies will be required to help characterise these subsets of patients.

Reduction of the Serum Levels of a Specific Biomarker of Cartilage Degradation (Coll2-1) by Hyaluronic Acid (KARTILAGE® CROSS) Compared to Placebo in Painful Knee Osteoarthritis Patients: the EPIKART Study, a Pilot Prospective Comparative Randomized Double Blind Trial

Background

Viscosupplementation is a symptomatic treatment of the knee osteoarthritis based on the intra-articular injection of hyaluronic acid (IAHA). Although many studies have investigated its effect on symptoms, few clinical studies have focused on its effects on biologicals markers of cartilage metabolism. In this study, we assessed the effect of an intra-articular injection of a reticulated hyaluronic acid compound on the level of a specific biomarker of type II collagen degradation.

Methods

Eighty one patients with symptomatic knee osteoarthritis were included in this randomized placebo controlled trial testing a reticulated hyaluronic acid (HA) with mannitol (KARTILAGE® CROSS, 16 mg/ml, one single injection of 2.2 mL; IAHA) versus saline solution. Primary outcome was the percentage of patients with a reduction of at least 10 nmol/l of serum Coll2-1 between baseline and day 90 (D90, 3 months after injection). Secondary outcomes concerned clinical evaluation and tolerance to the study product.

Results

A significant effect of IAHA was revealed by the sensitivity analysis of the decrease in cartilage marker. In the intention-to-treat population, the percentage of patients showing a decrease in the levels of serum Coll2-1 between inclusion and D90 showed was higher in HA (56.8%) than in placebo group (28.6%; P = 0.01). The same significant difference was observed between groups in the per protocol population (57.1% vs 29.0%; P = 0.02) corresponding to all patients having received the intra-articular injection (IA), being evaluated for the primary outcome on D-10 and D90, and with no major defined deviation. No significant differences between groups were observed on the changes in function (Lequesne index) or pain and on the number of adverse events.

Conclusions

This is the first randomized double-blind placebo controlled trial showing that IA injection of reticulated HA with mannitol in knee osteoarthritis patients can reduce the serum levels of Coll2-1, a marker specific of type II collagen degradation. This finding suggests that IAHA may have a beneficial effect on cartilage degradation and that Coll2-1 could be used for the assessment of a single intra-articular treatment in clinical trials.

Trial registration

NCT02951585; clinicaltrial.gov. Retrospectively registered on October 28, 2016.

A Critical Review: Management and Surgical Options for Articular Defects in the Hip

Patients with articular cartilage lesions of the hip may present with pain and symptoms that may be vague in nature and onset. Therefore, a thorough history and physical examination should be performed for every patient presenting with hip pain and/or disability. The management may be operative or nonoperative. Nonoperative management includes a trial of rest and/or activity modification, along with anti-inflammatory medications, physical therapy, and biologic injections. Operative treatment in the form of arthroscopic techniques continues to decrease morbidity and offer innovative solutions and new applications for microfracture, ACT, and AMIC.

Nonoperative Options for Management of Articular Cartilage Disease

Nonoperative options for articular cartilage injury are pervasive but have not shown to be curative. Recommendations for low-impact exercise and weight loss provide benefit and are a foundation for the treatment of osteoarthritis. Judicious use of NSAIDs and acetaminophen can be appropriate for pain management. Topical NSAIDs may be a treatment option with fewer side effects than its oral counterpart. Additionally, viscosupplementation injections are useful for mild to moderate knee osteoarthritis, whereas short-term pain relief is provided by intra-articular corticosteroid injections. Future studies to individualize treatment options based on patient phenotype and genotype may hold promise.

Clinical comparison of oral administration and viscosupplementation of hyaluronic acid (HA) in early knee osteoarthritis

PURPOSE

Osteoarthritis (OA) is a progressive, chronic and degenerative joint disease characterized by a loss of articular cartilage. Treatment of OA is largely palliative based on nonsteroidal anti-inflammatory drugs, opioids and injections of steroids. Regarding conservative treatment, intra-articular injections of hyaluronic acid (HA) can play a role in early symptomatic knee OA.

MATERIALS AND METHODS

Between August 2015 and September 2015, sixty patients (32 males and 28 females) between 40 and 70 years old were randomly allocated into two groups: Half were treated with three weekly intra-articular injections of hyaluronic acid 1.6 % (group A), while the others were treated with Syalox 300 Plus^® (hyaluronic acid 300 mg + Boswellia serrata extract 100 mg) 1 tab/die for 20 days and afterward Syalox 150^® (hyaluronic acid 150 mg) 1 tab/die for other 20 days (group B). All patients were evaluated clinically with American Knee Society Score (AKSS) and visual analogue scale (VAS) for the pain before the treatment and after 3 months.

RESULTS

AKSS of the patients in both groups was significantly increased by the treatment, and VAS score was significantly reduced. In both groups, two subgroups were created with patients older than 60 years and patients younger than 60 years. Better results are reported in younger patients of group A and older subjects in group B.

CONCLUSIONS

Despite several limitations, the results of the study have shown that HA injection and oral administration may have beneficial therapeutic effects on patients with early osteoarthritis. Different outcomes in younger and older subject suggested a combined therapy first with local infiltrations and then with oral composition.

Predictors of response to viscosupplementation in patients with hip osteoarthritis: results of a prospective, observational, multicentre, open-label, pilot study

Background

To identify predictive factors of response to viscosupplementation (VS) in patients with hip osteoarthritis (HOA).

Methods

Prospective, multicentre, open-label trial, achieved in daily practice conditions. Patients with HOA were treated with a single intra-articular injection of a cross-linked hyaluronic acid combined with mannitol (HAnox-M-XL), using imaging guidance. WOMAC pain and function scores and patient global assessment (PGA) were assessed at baseline and day 90. Improvement, satisfaction and efficacy were self-assessed at day 90.

Hip radiographs at baseline were scored using Kellgren-Lawrence grade and Osteoarthritis Research Society International (OARSI) score. Associations between clinical and radiological features and response to VS (pain improvement > 50% at day 90) were assessed in univariate analysis, and then using logistic regression, adjusted for confounding factors.

Results

The intent-to-treat (ITT) population included 97 patients (57 females, mean age 63). Ninety completed the follow-up and 80 had full clinical and radiological data. Response to VS was achieved in 47.8% of patients. In univariate analysis, the only clinical outcome statistically and negatively related to response was PGA at baseline (p = 0.047). Radiologically, response to VS was negatively correlated with joint space narrowing (JSN) score (JSN < 2 vs. JSN ≥ 2, p = 0.01) and was related to the patterns of femoral head migration (p = 0.008). In multivariate analysis, only JSN grade (p = 0.03) remained significantly related to a poor response.

Conclusion

This pilot study, which needs further confirmation by larger scale trials, suggests that radiological features might be of importance for the decision of VS in patients with HOA.

Trial registration number

ID RCB N°2013-A00165-40. Registered 31 January 2013.

[Osteoarthrosis: implementation of current diagnostic and therapeutic algorithms]

In the modern world, among the different clinical presentations of osteoarthritis, gonarthrosis and coxarthrosis exhibit the highest prevalence. In this paper, the characteristics of osteoarthritis and the different scales of assessment and classification of this pathology are exposed, to provide an exhibition of current evidence generated around diagnostic algorithms and treatment of osteoarthritis, with emphasis set out in the knee and hip, as these are the most frequent; a rational procedure for monitoring patients with osteoarthritis based on characteristic symptoms and the severity of the condition is also set. Finally, reference is made to the therapeutic benefits of the recent introduction of viscosupplementation with Hylan GF-20.