Comparison of Low-, Moderate-, and High-Molecular-Weight Hyaluronic Acid Injections in Delaying Time to Knee Surgery

Effects of Hyaluronic Acid (HA) and Platelet-Rich Plasma (PRP) on Mandibular Mobility in Temporomandibular Joint Disorders: A Controlled Clinical Trial

Hyaluronic acid (HA) is a glycosaminoglycan composed of D-glucuronic acid and N-acetylglucosamine with an up-to-several-million-Daltons chain-length responsible for the lubricating properties of the temporomandibular joint (TMJ) synovial fluid. Arthritis results in the predominance of HA degradation over synthesis leading to temporomandibular disorders (TMDs). TMD injection treatments are divided into HA supplementation and platelet-rich plasma (PRP) inflammation suppression. We questioned whether either approach lubricated the TMJ better and answered it in a two-arm equal-allocation trial with a non-concurrent active treatment control (two groups of 39 patients each). HA statistically significantly improved (p < 0.01) and PRP did not statistically significantly change (0.06 ≤ p ≤ 0.53) articular mobility compared to baselines in 128 TMJs. Statistically significant inter-group discrepancies were observed for abduction (MD = -4.05 mm; SE = 1.08; p = 0.00; d = -0.85) and protrusion (MD = -0.97 mm; SE = 0.43; p = 0.03; d = -0.51) but not for rightward (MD = -0.21; SE = 0.43; p = 0.63; d = -0.11) and leftward (MD = -0.30; SE = 0.42; p = 0.47; d = -0.16) movements. HA supplementation proved superior to PRP autografting in ad hoc TMJ lubrication and hence is more appropriate in hypomobile TMD cases of symptomatic treatment.

Hyaluronic Acid/Platelet-Rich Plasma Mixture Improves Temporomandibular Joint Biomechanics: A Systematic Review

Hyaluronic acid (HA) is the main component of the temporomandibular joint (TMJ) synovial fluid. Arthritis in temporomandibular disorders (TMDs) disrupts HA metabolism, resulting in shorter polymeric chain predominance and increased friction. Intra-articular injections of HA supplement the larger molecules of this glycosaminoglycan, and the platelet-rich plasma (PRP) delivered in this way releases growth factors, suppressing inflammation. This PRISMA-compliant PROSPERO-registered (CRD42024564382) systematic review aimed to assess the validity of mixing HA with PRP in the injectable treatment of TMJ disorders. We searched the medical literature for eligible randomized clinical trials using BASE, Google Scholar, PubMed and Scopus engines on 9 May 2024, with no time frame limit. Selected reports were assessed for risk of bias using the Cochrane RoB2 tool. Numerical data were collected on articular pain and mandibular mobility. We provided mean differences from baseline and between study and control groups at each observation point. The efficacy of TMD treatment with HA/PRP versus HA or PRP alone was assessed meta-analytically. Of 171 identified records, we selected 6 studies. In the 6-month follow-up, the mean advantage of PRP supplementation with HA was 2.52 (SE = 2.44; d = 0.83) mm and the benefit of adding PRP to HA was 1.47 (SE = 2.68; d = 0.34) mm in mandibular abduction. The pain-improvement scores were -1.33 (SE = 1.02; d = -1.05) and -1.18 (SE = 0.92; d = 0.80), respectively. Presumably, the HA/PRP range of therapeutic efficiency includes cases non-respondent to HA or PRP alone.

A randomized controlled trial for comparing efficacy and safety between intraarticular polynucleotide and hyaluronic acid for knee osteoarthritis treatment

Although the use of intra-articular polynucleotide (IA PN) injection as a viscosupplement for knee osteoarthritis (OA) treatment has been proposed, its efficacy and safety compared to high molecular weight hyaluronic acid (HMWHA) injection has not yet been established. The present double-blind, multicenter, randomized controlled trial aimed to investigate the efficacy and safety of IA PN injection compared to IA HMWHA injection. A total of 60 patients (15 men, 45 women, 64.5 ± 7.5 years) with knee OA (Kellgren-Lawrence grade 1-4) were randomly allocated to each group. All patients were given three IA injections of PN (n = 30) or HMWHA (n = 30) at intervals of 1 week. The primary endpoint was the change rate in weight-bearing pain (WBP) 16 weeks from the baseline. The secondary endpoint included multiple measurements: the change rate in WBP rate at 8 weeks; the change rate in pain level at rest and during walking at 8 and 16 weeks; the Korean-Western Ontario and McMaster University Osteoarthritis index; the Euro-Quality of Life-5 Dimension; Clinical Global Impression, Patient Global Impression at 8 and16 weeks, and total consumption of rescue medicine. The mean change rate in the WBP at 16 weeks from the baseline was - 54.0 ± 38.1% in the IA PN group and - 42.8 (± 35.8%) in the IA HMWHA group, and there was no significant difference between the two groups (p = 0.296). All secondary endpoints related with pain and functional outcome also showed no significant difference between the two groups. Pain at the injection site and swelling were reported as adverse events, and the incidence was similar between the two groups. IA PN showed comparable efficacy and safety to IA HMWHA at 3 times injection with an interval of 1 week. IA PN can be useful alternative to IA HMWHA for the treatment of knee OA.

Modification of hyaluronic acid to enable click chemistry photo-crosslinking of hydrogels with tailorable degradation profiles

Hyaluronic acid (HA) is a naturally occurring mucopolysaccharide that, due to its inherent bioactivity and extracellular matrix-like structure, has the potential to be utilised extensively in tissue engineering. However, this glycosaminoglycan lacks the properties required for cellular adhesion and photo-crosslinking by UV light, which significantly hinders this polymers applicability. This research presents a method for modifying hyaluronic acid via thiolation and methacrylation to generate a novel photo-crosslinkable polymer with improved physicochemical properties, biocompatibility and the potential to customize biodegradability according to the ratio of monomers used. A decrease in stiffness proportional to increasing thiol concentration was observed when testing the compressive strength of hydrogels. Conversely, it was noted that the storage moduli of hydrogels increased proportionally to thiol concentration indicating a greater degree of cross-linking with the addition of thiol. The addition of thiol to HA increased the biocompatibility of the material in both neuronal and glial cell lines and improved the degradability of methacrylated HA. Due to the enhanced physicochemical properties and biocompatibility imparted by the introduction of thiolated HA, this novel hydrogel system could have numerous bioengineering applications.

Propensity Scores: Confounder Adjustment When Comparing Nonrandomized Groups in Orthopaedic Surgery

Many studies in arthroplasty research are based on nonrandomized, retrospective, registry-based cohorts. In these types of studies, patients belonging to different treatment or exposure groups often differ with respect to patient characteristics, medical histories, surgical indications, or other factors. Consequently, comparisons of nonrandomized groups are often subject to treatment selection bias and confounding. Propensity scores can be used to balance cohort characteristics, thus helping to minimize potential bias and confounding. This article explains how propensity scores are created and describes multiple ways in which they can be applied in the analysis of nonrandomized studies. Please visit the following (https://www.youtube.com/watch?v=sqgxl_nZWS4&t=3s) for a video that explains the highlights of the paper in practical terms.

Patient Reported Outcomes Following Intraarticular Hyaluronic Acid for Knee Osteoarthritis

BACKGROUND

Intraarticular hyaluronic acid (IAHA) has been commonly used in the management of knee osteoarthritis (OA). This study sought to assess patient reported outcomes (PRO) following different formulations of HA injections for patients who have knee OA.

METHODS

A retrospective analysis was performed on patients who have knee OA and received IAHA knee injections from October 2018 to May 2022 in sports medicine (SM) and adult reconstructive (AR) clinics. Patients completed PRO measures including the Patient-Reported Outcome Measurement Information System (PROMIS ®) Mobility, Pain Interference, and Pain Intensity at baseline, 6-week, 6-month, and 12-month follow-up. Univariate and multivariate analyses were used to evaluate changes in PRO measures between baseline and follow-up periods and to evaluate differences between the SM and AR divisions. A total of 995 patients received IAHA for knee OA and completed PRO assessments.

RESULTS

There was no difference in the PROMIS® measures based on molecular weight at 6-weeks, 6-months, and 12-months. Except for 6-month Mobility scores between the SM and AR patients (-0.52 ± 5.46 vs 2.03 ± 6.95; P = 0.02), all other PROMIS® scores were similar. Mobility scores at 6-months were significantly different based on KL (Kellgren and Lawrence) grade (P = 0.005) but all other PROMIS® scores were similar.

CONCLUSION

Average change in PROMIS® scores were significantly different only for 6-month Mobility scores based on divisions and KL grade, but did not achieve minimally clinical important difference in most timepoints. Further studies are needed to investigate whether improvement is observed in specific patient populations.

Impact of Kefiran Exopolysaccharide Extraction on Its Applicability for Tissue Engineering and Regenerative Medicine

Kefiran is an exopolysaccharide produced by the microflora of kefir grains used to produce the fermented milk beverage kefir. The health-promoting and physicochemical properties of kefiran led to its exploration for a range of applications, mainly in the food industry and biomedical fields. Aiming to explore its potential for tissue engineering and regenerative medicine (TERM) applications, the kefiran biopolymer obtained through three different extraction methodologies was fully characterized and compared. High-quality kefiran polysaccharides were recovered with suitable yield through different extraction protocols. The methods consisted of heating the kefir grains prior to recovering kefiran by centrifugation and differed mainly in the precipitation steps included before lyophilization. Then, kefiran scaffolds were successfully produced from each extract by cryogelation and freeze-drying. In all extracts, it was possible to identify the molecular structure of the kefiran polysaccharide through ¹H-NMR and FTIR spectra. The kefiran from extraction 1 showed the highest molecular weight (~3000 kDa) and the best rheological properties, showing a pseudoplastic behavior; its scaffold presented the highest value of porosity (93.2% ± 2), and wall thickness (85.8 µm ± 16.3). All extracts showed thermal stability, good injectability and desirable viscoelastic properties; the developed scaffolds demonstrated mechanical stability, elastic behavior, and pore size comprised between 98–94 µm. Additionally, all kefiran products proved to be non-cytotoxic over L929 cells. The interesting structural, physicochemical, and biological properties showed by the kefiran extracts and cryogels revealed their biomedical potential and suitability for TERM applications.

Effects of Repeated Co-Injections of Corticosteroids and Hyaluronic Acid on Knee Osteoarthritis: A Prospective, Double-Blind Randomized Controlled Trial

BACKGROUND

We compared the effects of repeated co-injections of corticosteroids plus hyaluronic acid (HA) with the effects of HA injections alone in patients with knee osteoarthritis.

METHODS

A double-blind randomized controlled trial was conducted between October 2016 and July 2017 at a medical center. Patients (n = 57) who fulfilled the clinical and radiographic criteria for knee osteoarthritis established by the American College of Rheumatology with a Kellgren-Lawrence score of 2 or 3 were included. They were assigned to either the HA group (n = 29) or corticosteroids plus HA group (n = 28), and injections were administered under ultrasound guidance once a week for 3 consecutive weeks. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were the primary outcomes. Physical functional performance (10-m fast walking and chair-rising time) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were secondary outcomes. The assessment was performed prior to injections, 1 week, and 1, 3, and 6 months after injections. Data were analyzed through repeated-measures analysis of covariance.

RESULTS

Both groups experienced decreased pain and improved physical function and physical functional performance over time. We found significant group × time interaction effects favoring the corticosteroids plus HA group in WOMAC-pain (P = .005) and physical function (P = .005), chair-rising time (P = .032), and KOOS-pain (P = .001).

CONCLUSIONS

Repeated co-injections of corticosteroids plus HA more effectively decreased pain and improved physical function and physical functional performance than injections of HA alone from 1 week through 6 months posttreatment.

Role and Effectiveness of Intra-articular Injection of Hyaluronic Acid in the Treatment of Knee Osteoarthritis: A Systematic Review

Osteoarthritis (OA) is a degenerative joint disease that causes persistent joint pain and stiffness of mainly the large peripheral weight-bearing joints. It is a leading cause of functional disability and poor quality of life. Various modalities of therapy are recommended by different research organizations at different stages of OA including non-pharmacological, pharmacological, and surgical interventions. Intra-articular injections of hyaluronic acid (HA) is widely used for over three decades in the treatment of OA. However controversies exist regarding its safety and efficacy, the number of injections and courses, type of preparation, duration of its effects, and combining it with other drugs or molecules. This study aimed to review the most recent data available in the published literature to address these. Electronic databases like Medline, Embase, ProQuest, and Google Scholar were searched for articles using keywords, intraarticular injections, hyaluronic acid, and osteoarthritis knee. The review was carried out as per PRISMA guidelines. Thirty-eight randomized control trials (RCTs) investigating the efficacy and safety of intra-articular injection of HA were included in the systematic review. Out of the 38 studies, 22 (57.9%) were double-blind, eight (21%) single-blind, three (7.9%) non-blind, four (10%) with simple randomization, and one (2.7%) was open-labeled. Total 5,025 patients were included in these studies. The mean age of the patients was 60.28 years and the osteoarthritis grade of the knee joint was 1 to 3. HA was studied as a test preparation in 19 (50%) while in another 19 (50%) it was studied as a control. In 24 (63.2%) studies, HA was used as high molecular weight preparation in eight (21%) as low molecular weight preparation while in six studies the information was not available. HA was used as a standalone preparation in 31 studies, in two studies it was injected with platelet-rich plasma (PRP) and with either low-level laser therapy (LLLT), triamcinolone (TA), betamethasone (CS), poly deoxyribonucleotide (PDRN) or dexamethasone (DX) in one study each. In the majority of the studies, HA was given as a single injection (52.6% studies) or weekly three injections (28.9% studies). In 13.2 %, it was given as weekly 5 injections and in 5.3% as weekly two injections. IA-HA injections have a limited role in the treatment of knee osteoarthritis in those patients who do not have sufficient pain relief with topical or oral medication and physical therapy. It is safe and effective except for minor side effects such as local pain and swelling lasting for a few days. Severe allergic reactions are extremely rare. They provide adequate pain relief and functional improvement for up to six months irrespective of a number of injections and type of preparations used. The combination formulations with corticosteroids or PRP or MSCs show better results than HA alone. Combining HA with newer molecules such as peptides or diclofenac for sustained and disease-modifying effects requires more studies in the future.

Nanoforming Hyaluronan-Based Thermoresponsive Hydrogels: Optimized and Tunable Functionality in Osteoarthritis Management

Hyaluronic acid (HA) constitutes a versatile chemical framework for the development of osteoarthritis pain treatment by means of injection in the joints, so-called viscosupplementation. Without appropriate physico-chemical tuning, such preparations are inherently hindered by prompt in vivo degradation, mediated by hyaluronidases and oxidative stress. To prolong hydrogel residence time and confer optimized product functionality, novel thermoresponsive nanoforming HA derivatives were proposed and characterized. Combined use of sulfo-dibenzocyclooctyne-PEG4-amine linkers and poly(N-isopropylacrylamide) in green chemistry process enabled the synthesis of HA-based polymers, with in situ obtention of appropriate viscoelastic properties. Spontaneous and reversible thermoformation of nanoparticles above 30 °C was experimentally confirmed. Lead formulations were compared to a commercially available HA-based product and shown significantly better in vitro resistance to enzymatic and oxidative degradation, required half the injection force with optimal viscoelastic hydrogel properties in equine synovial fluids. Results highlighted the vast potential of appropriately engineered HA-based systems as next-generation long-acting viscosupplementation products for osteoarthritic patients.

Analysis of the Cost and Efficacy of Intra-Articular Knee Injections

INTRODUCTION

Intra-articular joint injections have been used with the goal of providing patients with symptomatic relief. Recently, however, the efficacy of corticosteroid (CS) and hyaluronic acid (HA) injections in the management of knee osteoarthritis (OA) is questionable. In this analysis, we investigated the costs associated with injections by assessing overall use, conversion and average time to total knee arthroplasty (TKA), and reimbursement.

METHODS

Patients aged 50 to 70 years with a knee-related diagnosis of pain, effusion, or OA were identified in the Humana insurance national data set. Patients who received intra-articular injections were stratified by the type and number of injection(s) received. The subsequent rates of TKA were compared with Kaplan-Meier curves for patients who underwent CS injections, HA injections, and a benchmarking cohort of patients with OA and no history of knee injections in the medical record. Average time to TKA was determined from index diagnosis, and total cost was compared using Wilcoxon rank sum analyses.

RESULTS

A total of 778,686 patients were identified. Of these, 637,112 had no knee injection history, while 124,129 received CS and 17,445 received HA injections. The 10-year conversion to TKA was highest in HA cohort (31.6%), followed by the CS cohort (24.0%) and the noninjection cohort (7.3%) (P < 0.001). Time to TKA increased with number of injections for both injection types. For patients who underwent TKA, median cost was greater in HA ($16,687) and CS ($15,563) cohorts relative to noninjection cohort ($14,733) (P < 0.001).

DISCUSSION

Compared with the noninjection cohort, both HA and CS cohorts experienced increased costs and increased time to TKA. However, while the cost incurred in HA cohort was greater than that in CS cohort, no appreciable benefit was demonstrated for conversion or time to TKA. Therefore, if intra-articular knee injections are indicated for the nonsurgical management of knee OA, the results of this study support CS over HA.

Delay to TKA and Costs Associated with Knee Osteoarthritis Care Using Intra-Articular Hyaluronic Acid: Analysis of an Administrative Database

Background

Total knee arthroplasty (TKA) is a surgical treatment for patients with knee osteoarthritis (KOA) that no longer experience symptom relief from non-operative or pharmacologic treatments. Non-operative KOA management aims to address patient symptoms and improve function, as well as forestall or mitigate the large costs associated with TKA. The primary objective of this study was to examine the relationship between intra-articular hyaluronic acid (IA-HA) treatment and delaying TKA in patients with KOA compared to patients not receiving IA-HA, as well as to identify differences in KOA-related costs incurred among patients who received or did not receive IA-HA.

Methods

This was a retrospective analysis of an administrative claims database from October 1st, 2010 through September 30th, 2015. Kaplan-Meier survival analysis was conducted to determine the TKA-free survival of patients who received IA-HA, stratified by the number of injection courses received versus those who did not receive any IA-HA. Median KOA-related costs per year were calculated for 2 comparisons: (1) patients who received IA-HA versus patients who did not receive IA-HA, among patients who eventually had TKA, and (2) patients who received IA-HA versus patients who did not receive IA-HA, among patients who did not have TKA.

Results

A total of 744 734 patients were included in the analysis. A delay to TKA was observed after IA-HA treatment for patients treated with IA-HA compared to those who did not receive IA-HA. At 1 year, the TKA-free survival was 85.8% (95% CI: 85.6%-86.0%) for patients who received IA-HA and 74.1% (95% CI: 74.0%-74.3%) for those who did not receive IA-HA. At 2 years, the TKA free survival was 70.8% (70.5%-71.1%) and 63.7% (63.5%-63.9%) in the 2 groups, respectively. Patients treated with multiple courses of IA-HA demonstrated an incremental increase in delay to TKA with more courses of IA-HA, suggesting that the risk of TKA over the study time period is reduced with additional IA-HA courses. The hazard ratio for the need of TKA was 0.85 (95% CI 0.84-0.86) for a single course and 0.27 (95% CI 0.25-0.28) for ⩾5 courses, both compared to the no IA-HA group. In patients that eventually had TKA, the median KOA-related costs were lower among those who received IA-HA before their TKA ($860.24, 95% CI: 446.65-1722.20), compared to those who did not receive IA-HA ($2659.49, 95% CI: 891.04-7480.38). For patients who did not have TKA, the median and interquartile range (IQR) KOA-related costs per year were similar for patients who received IA-HA compared with those who did not.

Conclusion

These results demonstrate that within a large cohort of KOA patients, individuals who received multiple courses of IA-HA had a progressively greater delay to TKA compared to patients who did not receive IA-HA treatment. Also, for patients who progressed to TKA, IA-HA treatment was associated with a large reduction in KOA-related healthcare costs. Based on these results, multiple, repeat courses of IA-HA may be beneficial in substantially delaying TKA in KOA patients, as well as minimizing KOA-related healthcare costs.

Comparing Intra-articular Injections of Leukocyte-Poor Platelet-Rich Plasma Versus Low-Molecular Weight Hyaluronic Acid for the Treatment of Symptomatic Osteoarthritis of the Hip: A Double-Blind, Randomized Pilot Study

Background:

Hyaluronic acid (HA) and leukocyte-poor platelet-rich plasma (LP-PRP) are 2 nonoperative treatment options that have been studied in patients with hip osteoarthritis (OA).

Purpose:

To compare the efficacy of intra-articular injections of low–molecular weight (LMW) HA and LP-PRP in patients with hip OA.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 34 patients (36 hips) presenting with signs of hip OA were randomized to receive 3 blinded, weekly intra-articular injections of either LP-PRP or LMW-HA. Patients were prospectively evaluated before injections and at 6 weeks and then at 3, 6, 12, and 24 months. The primary outcome, conversion to total hip arthroplasty (THA) or a hip resurfacing procedure, was analyzed along with secondary outcomes including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and hip range of motion.

Results:

The final analysis included 33 hips (mean Kellgren-Lawrence grade, 2.73) (LMW-HA: n = 14; LP-PRP: n = 19) in 31 patients (18 male; mean age, 53.8 years). Significantly more patients converted to THA or a hip resurfacing procedure in the LMW-HA group (7/14; 50.0%) (mean, 1.3 years after first injection) than the LP-PRP group (3/19; 15.8%) (mean, 0.73 years after first injection) (P = .035). There was no significant improvement or decline in any outcome scores within the LMW-HA group from before injections to 6 weeks or 3, 6, and 12 months. For the LP-PRP group, WOMAC overall (P = .032), joint (P = .030), and function scores (P = .025) significantly improved from before injections to 6 weeks, and WOMAC joint scores significantly improved from before injections to 6 months (P = .036). When comparing the difference between groups in internal rotation at 90° of hip flexion from before injections to 6 months, the LP-PRP group demonstrated a mean 5.0° improvement, while the LMW-HA group showed a mean 1.5° decrease (P = .028).

Conclusion:

Intra-articular hip injections of LP-PRP in patients with hip OA resulted in an improvement in WOMAC scores and hip internal rotation at 6 months and delayed the need for THA or a hip resurfacing procedure compared with treatment with LMW-HA. A longer follow-up is necessary to further compare the effects of LP-PRP and LMW-HA injections in patients with hip OA.

Registration:

NCT01920152 (ClinicalTrials.gov identifier).

High-concentration nonavian high-molecular weight hyaluronan injections and time-to-total knee replacement surgery

Aim: To examine the time-to-total knee replacement (TKR) surgery among patients with high-concentration nonavian high-molecular-weight hyaluronan injection (HMW-HA) compared with those without HA injections. Materials & methods: Using MarketScan^® Commercial claims all patients aged 18-64 who underwent TKR surgery between 2008 and 2017 were identified. Time-to-TKR surgery was compared between patients receiving Orthovisc^® (Anika Therapeutics Inc. Bedford MA, USA, referred to as nonavian HMW-HA) injections and patients who did not receive an HA injection. Results: The median time-to-TKR surgery was 893 days in the nonavian HMW-HA cohort and 399 days in the non-HA cohort (p < 0.001), a difference of 494 days (16.2 months). Conclusion: This study demonstrates that the time-to-TKR surgery is 16.2 months longer in patients who received treatment with nonavian HMW-HA injections.

Rethinking Viscosupplementation: Ultrasound- Versus Landmark-Guided Injection for Knee Osteoarthritis

OBJECTIVES

Viscosupplementation, intra-articular injection of hyaluronic acid (HA), for knee osteoarthritis has fallen somewhat out of favor, with studies failing to show consistent benefits in pain reduction. Hyaluronic acid must enter the joint space to be beneficial; however, landmark-guided injection can be substantially inaccurate, especially in obese patients. We aimed to determine whether ultrasound (US) guidance to ensure needle placement for HA knee injection resulted in improved outcomes as reflected by surgery-free survival compared to landmark-guided HA knee injection.

METHODS

All community-dwelling patients in 6 contiguous surrounding counties receiving HA knee injection either by landmark guidance (n = 647) or by US guidance (n = 500) were analyzed for the degree of arthritis, body mass index, follow-up injection, and subsequent need for knee arthroplasty. A subgroup analysis of obese patients was also performed.

RESULTS

The US- and landmark-guided HA injection cohorts were similar with respect to sex, body mass index, and the degree of arthritis. Of 1147 patients receiving knee HA injection, 462 subsequently underwent knee arthroplasty. Significantly fewer patients in the US-guided HA injection cohort went to surgery (33.2%) compared to the landmark-guided cohort (45.8%; P < .001). The subgroup analysis for obese patients showed even larger differences (34.8% versus 51.8%; P < .001).

CONCLUSIONS

Knee osteoarthritis treatment by viscosupplementation can be optimized by US guidance, ensuring intra-articular needle placement. Using an objective surgical outcome, our study shows that rethinking viscosupplementation to ensure intra-articular delivery improves effectiveness. Patients receiving US-guided knee HA injection were significantly less likely to undergo subsequent knee arthroplasty than patients receiving landmark-guided HA injection.

Viscosupplementation for Management of Knee Osteoarthritis from an Indian Perspective: An Expert Consensus Report

INTRODUCTION

Knee osteoarthritis (OA) is a progressive degenerative condition and is a significant contributor toward physical disability in the aging population. The current treatment modalities for this condition focus on joint preservation with alleviation of symptoms. Intra-articular hyaluronic acid (IAHA) injections have emerged as the promising mainstay of nonsurgical treatment of OA, especially in patients with mild-to-moderate OA and in certain subgroups of severe OA with comorbidities or with poor response to first-line therapy. The absence of standard guidelines or recommendations for the use of IAHA in India has led to vast variations in the usage of IAHA among practitioners. Hence, this consensus-based document aims to address the issue and establish simplified and easily implemented recommendations on the use of IAHA.

METHODS

A group of 78 expert orthopedic surgeons discussed in detail the evidence on appropriate criteria for diagnosis, patient selection, and follow-up evaluation for knee OA at two national meetings. In subsequently held regional meetings, key discussion points and clinical experience-based answers were translated into a questionnaire to develop the final expert consensus-based statements for the use of IAHA in patients with knee OA.

RESULTS

Various consensus statements were obtained on the basis of scientific evidence obtained from PubMed, Cochrane-indexed database, and guidelines related to viscosupplementation and knee OA as well as the experts' clinical experience. This document was drafted, reviewed, validated, and modified by the expert panel until a final agreement was reached.

CONCLUSION

In this pioneering attempt, the document lays down structured, expert consensus-based statements to guide and align practitioners on the appropriate use of IAHA in the Indian setting.

FUNDING

Dr. Reddy's Laboratories Ltd.

A Single Intra-Articular Injection of Gel-200 for Treatment of Symptomatic Osteoarthritis of the Knee Is More Effective than Phosphate Buffered Saline at 6 Months: A Subgroup Analysis of a Multicenter, Randomized Controlled Trial

OBJECTIVE

Many clinical trials of viscosupplementation have been conducted, although only the Gel-200 (primary) trial included a different patient population. A subgroup analysis of a multicenter, randomized controlled trial comparing the efficacy of single intra-articular injections of Gel-200 with phosphate buffered saline (PBS) was performed to demonstrate its benefit as treatment of osteoarthritis of the knee in a population similar to those of other reported trials of viscosupplementation.

DESIGN

The subgroup population was defined as patients in the intention-to-treat (ITT) population who met the specified criteria. Changes from baseline in Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores following treatment with Gel-200 or PBS were derived from a longitudinal model and treatment differences compared between groups at weeks 12 and 26, and over 26 weeks.

RESULTS

The subgroup included 311 subjects (152 Gel-200; 159 PBS). Mean improvements from baseline in WOMAC pain subscores in the Gel-200 over PBS groups were statistically significant at week 12 (P = 0.031) and week 26 (P = 0.019). Treatment group differences in WOMAC stiffness and total scores were statistically significant at week 26 (P = 0.023 and P = 0.036, respectively).

CONCLUSIONS

The efficacy of Gel-200 following a single injection for knee osteoarthritis was demonstrated in WOMAC pain, stiffness, and total scores as well as clinically important improvements in pain at 26 weeks in this subset of patients with comparable characteristics to populations evaluated in other viscosupplementation treatment trials.

Estimation of high-dimensional propensity scores with multiple exposure levels

PURPOSE

Little information is available on the performance of high-dimensional propensity scores (HDPS) in settings with more than two exposure levels. Our objective was to adapt the HDPS algorithm to allow for the inclusion of multilevel treatments and compare estimates obtained via this approach with those obtained via pairwise comparisons in a case study using real-world data.

METHODS

We conducted a retrospective cohort study of cardiovascular events associated with three smoking cessation drugs (varenicline, bupropion, nicotine replacement therapy [NRT]) using the Clinical Practice Research Datalink. We applied the binary HDPS algorithm adjusted for pre-specified and empirically-selected covariates to cohorts formed by each treatment pair. We then constructed multinomial HDPS models on a cohort of new users of any of the three drugs, adjusting for predefined covariates and different combinations of empirically-selected covariates. After trimming the area of non-overlap of the HDPS distributions, the effects of the study drugs on cardiovascular events were estimated with the Cox proportional hazards models adjusted for propensity score category.

RESULTS

Outcome models adjusted for multinomial HDPS estimated treatment effects that were slightly more protective than those estimated in pairwise comparisons (varenicline vs NRT: HR_Multinomial = 0.60-0.62, HR_Pairwise = 0.64; bupropion vs NRT: HR_Multinomial = 0.70-0.72, HR_Pairwise = 0.76). Trimming rates were similar between the two approaches.

CONCLUSIONS

The extension of HDPS to multilevel exposures is a valid and practical approach to confounder control that may be useful when comparing different classes of drugs prescribed for the same indication or different molecules within a given drug class.

Structural Modifications and Solution Behavior of Hyaluronic Acid Degraded with High pH and Temperature

Hyaluronic acid (HA) is a macromolecule with valuable benefits over its range of molar masses (MM). Degradation studies are relevant to maintain the same purity level in biomedical studies when using HA of different MM. We degraded HA via high pH and temperature and evaluated its MM, solution behavior, and structure over time. After 24 h, low MM HA was predominant, and the MM decreased from 753 to 36.2 kDa. Dynamic light scattering (DLS) showed a decrease in the number of HA populations, and the solution tended to be less polydispersed. The zeta potential varied from - 10 to - 30 mV, close to the stable range. FTIR showed that the primary structure of HA was affected after only 48 h of reaction. These results are relevant for the production of low MM HA to be used or mixed with high MM HA, generating structured biomaterials for biomedical applications.

Active viscosupplements for osteoarthritis treatment

OBJECTIVE

Osteoarthritis is a chronic, painful and disabling disease which prevalence is increasing in developing countries. Patients with osteoarthritis present a reduced synovial fluid viscoelasticity due to a reduction in concentration and molecular weight of hyaluronic acid. Currently, the main treatment used to restore the compromised rheological properties of synovial fluid is the viscosupplementation by hyaluronic acid injections that can be combined with oral anti-inflammatory drugs for pain relief. Combination of viscosupplements with chemical agents or drugs is emerging as a new strategy to provide a double action of synovial fluid viscoelasticity recovery and the therapeutic effect of the bioactive principle.

METHODS

In this review, we present the latest research on the combination of viscosupplements with active molecules. We conducted a literature review of articles published in different web search engines and categorized according to the active molecule introduced into the viscosupplement.

RESULTS

Generally, the introduction of anti-inflammatory molecules have shown to improve pain relief although some cytotoxicity has been demonstrated especially for non-steroidal anti-inflammatory drugs. Other molecules such as antioxidant or disease modifying osteoarthritis drugs have been reported to improve viscosupplementation action. Drug delivery systems combined with hyaluronic acid could enhance the activity of the encapsulated molecules and provide better control over the drug release. Finally, biological approaches such as the use of stem cells or platelet-rich plasma seem to be the most promising strategies for cartilage recovery.

CONCLUSIONS

Combination therapy of viscosupplements with therapeutic agents, drug delivery systems or regenerative therapies can improve viscosupplementation outcome in terms of pain relief and joint functionality. However, further research is needed in order to reach more conclusive results.

Recent advances in hyaluronic acid based therapy for osteoarthritis

Osteoarthritis is a debilitating disease that has increased in prevalence across the world due to the aging population. Currently, physicians use a plethora of treatment strategies to try and slow down the progression of the disease, but none have been shown to ubiquitously treat and cure the disease. One of the strategies uses the high molecular weight molecule hyaluronic acid as either an injectable or oral supplement for treatment. Hyaluronic acid (HA) is a relatively new treatment that has shown varied results through several clinical trials. It can be used as a scaffold for engineering new treatments and several new preparations have just been added to the market. A comprehensive search was conducted through several search databases according our inclusion and exclusion criteria. This review included 44 prospective clinical trial investigating the feasibility and efficacy of HA injection for knee, hip, and ankle osteoarthritis. This review will take a closer look at hyaluronic acid and its properties, as well clinical effectiveness and future options.