Intra-articular placebo effect in the treatment of knee osteoarthritis: a survey of the current clinical evidence

Knee osteoarthritis (KOA) is a debilitating disease characterized by chronic pain, stiffness, and decreased mobility. Intra-articular injectable therapies show good clinical efficacy in improving symptoms; however, these therapies and their comparators (intra-articular saline) have been associated with a large underlying placebo effect. We aimed to describe the existing evidence on the challenges, hypotheses, and potential solutions to mitigate the intra-articular placebo effect in clinical trials in KOA. A targeted literature review was conducted by searching Embase, MEDLINE®, and CENTRAL using predefined study selection criteria. All eligible studies identified were extracted for relevant data, and results were narratively summarized. Forty-three studies were included following screening. Challenges associated with the intra-articular placebo effect included its ability to mask the comparative efficacy of active treatments in trials (n = 7 studies), long-lasting effects (up to 6 months; n = 3), and substantial variation of placebo effect sizes across populations (n = 3). Hypotheses for the mechanism of the placebo effect included aspiration of synovial fluid during administration (n = 6) and dilution of inflammatory mediators (n = 2). Factors affecting the placebo effect size were more invasive routes of administration (e.g., injection versus oral; n = 4) and patient expectations (n = 2). Proposed solutions included the suggestion for readers to weigh the relevance of clinical trial evidence against the presence of large underlying placebo effects (n = 9), discontinuation of intra-articular saline as an appropriate placebo (n = 5), and inclusion of 'no treatment' or sham injection as a control (n = 4). The intra-articular placebo effect is a well-documented occurrence in KOA clinical trials, and it is suggested that it be accounted for when designing randomized controlled trials. Awareness and understanding of the intra-articular placebo effect in KOA are required for fair interpretation of clinical trial evidence.

A Comprehensive Review of Viscosupplementation in Osteoarthritis of the Knee

PURPOSE OF REVIEW

The purpose of this systematic review is to discuss emerging evidence in the field of viscosupplementation for chronic knee pain secondary to Osteoarthritis (OA). This review focuses on types of viscosupplementation that are clinically available currently, evidence to support their use, contraindications, and adverse events.

RECENT FINDINGS

OA, also known as degenerative joint disease, is the most common form of arthritis in the United States, affecting 54.4 million, or 22.7% of the adult population. The knee is the most common joint affected in OA, with up to 41% involvement, 30% in the hands, and 19% in the hips. The pathophysiology of OA is complex, with contributing factors including mechanical stress to the joint, as well as many person-specific factors such as genetic susceptibility, ethnicity, nutrition, and sex. Treatment modalities include weight control, exercise, non-steroidal and steroidal anti-inflammatory drugs, opioids, intra-articular platelet-rich plasma, placebo, corticosteroid injection, intra-articular viscosupplementation, and surgery. Viscosupplementation consists of injection of hyaluronic acid (HA) into affected joints, intending to restore the physiologic viscoelasticity in the synovial fluid (SF) in the absence of inflammation. HA has also been shown to downregulate pro-inflammatory factors, such as PGE2 and NFkB, and proteases and proteinases known to break down the joint matrix.The contraindications for HA injection are similar to any other injection therapy, and adverse events are usually mild, local, and transient. Viscosupplementation (VS) is effective over placebo and more effective than NSAIDs and corticosteroids in pain reduction and improved functionality; however, guidelines recommend neither for nor against its use, demonstrating variability in the existing evidence base.Current VS options divide primarily into native vs. cross-linked and low-molecular-weight vs. high-molecular-weight. Current treatment options include Hylan g-f-20, Sodium Hyaluronate preparations (Suparts Fx, Euflexxa, Gelsyn-3, Durolane, Hyalgen), single-use agents (Gel-One, Synvisc-One, Monovisc), and Hyaluronan (Orthovisc, Monovisc, Hymovic). They share a common safety profile, and all have evidence supporting their efficacy. Their specific details are reviewed here.

SUMMARY

OA is the most common form of arthritis. It is a chronic, debilitating illness with a high impact on the functionality and quality of life of a significant part of the population in the western world. Treatments include medical management, physical therapy, activity modification, injection, and surgery. VS effectively reduces pain, increases functionality, and delays surgery in the knee to treat osteoarthritis. While previous studies have demonstrated variable results, more evidence is becoming available generally supportive of the benefit of VS in the treatment of knee OA.

Pilot Study to Evaluate the Efficacy of Polynucleotide Sodium Compared to Sodium Hyaluronate and Crosslinked Sodium Hyaluronate in Patients with Knee Osteoarthritis

Degenerative arthritis of the knee joint has become a major social problem worldwide due to population aging. There are several treatment options for knee osteoarthritis, and the intraarticular injection of sodium hyaluronate is commonly selected by many clinicians as a nonsurgical treatment. However, the efficacy of the treatment is controversial. In this pilot study, we aimed to compare polynucleotide sodium (Conjuran^®) with sodium hyaluronate (Hyruan Plus^®) and 1,4-butanediol diglycidyl ether-crosslinked sodium hyaluronate (Synovian^®) in terms of analgesic efficacy after intraarticular injection in patients with knee osteoarthritis. One of the three intraarticular agents was selected according to what agents were available for outpatients when each patient was enrolled in the study. The 15 enrolled patients were subdivided into 3 groups of 5 patients each. Three injections were performed under ultrasound guidance at a 1-week intervals over a total of 3 weeks. The visual analog scale (VAS) score, the Korean version of the Western Ontario and McMaster Universities Arthritis Index (K-WOMAC), the EuroQol five-dimension scale (EQ-5D) score, and the Korean version of the painDETECT Questionnaire (K-PDQ) score were evaluated before injection and at 1, 2, and 6 weeks after the start of the treatment protocol. The primary endpoint was the change in weight-bearing pain at 4 weeks after the last injection. Secondary endpoints included pain at rest and during walking and the K-WOMAC, EQ-5D, and K-PDQ scores. Weight-bearing pain decreased significantly more from pretreatment to 6 weeks after the start of the treatment protocol in the polynucleotide sodium-treated patients than in the patients who were treated with other agents (p = 0.006, one-way ANOVA). There were no significant between-group differences in the other secondary endpoints. No adverse events occurred. In conclusion, polynucleotide sodium could effectively reduce weight-bearing pain in the patients with knee osteoarthritis compared to standard hyaluronic acid viscosupplementation.

Extracellular Matrix Mimics Using Hyaluronan-Based Biomaterials

Hyaluronan (HA) is a critical element of the extracellular matrix (ECM). The regulated synthesis and degradation of HA modulates the ECM chemical and physical properties that, in turn, influence cellular behavior. HA triggers signaling pathways associated with the adhesion, proliferation, migration, and differentiation of cells, mediated by its interaction with specific cellular receptors or by tuning the mechanical properties of the ECM. This review summarizes the recent advances on strategies used to mimic the HA present in the ECM to study healthy or pathological cellular behavior. This includes the development of HA-based 2D and 3D in vitro tissue models for the seeding and encapsulation of cells, respectively, and HA particles as carriers for the targeted delivery of therapeutic agents.

Impact of refractive index increment on the determination of molecular weight of hyaluronic acid by muti-angle laser light-scattering technique

Hyaluronic acid (HA) is applied in a number of medical applications and HA of different molecular weight (Mw) are used in different pharmaceutical preparations. In determination of Mw by muti-angle laser light-scattering (MALS), refractive index increment (dn/dc) is an important parameter for accuracy. Herein, the influence of dn/dc on the Mw of HA in stroke-physiological saline solution is investigated by MALS in this work. Additionally, the Mw variation of HA in the manufacturing process of preparations is measured. It is shown that each HA sample corresponds to a specific value of dn/dc, which is varied from 1.38 to 1.74 L/g with the Mw increasing from 13.5 to 2840 kDa in solution. It is indicated by the results from both MALS approach and viscometry that appropriate dn/dc should be selected for Mw determination. In steam sterilization process of preparations at 121 °C, the Mw and conformation of HA can be accurately and rapidly determined by MALS. This work provides a precise method to determine the Mw of HA in the medical applications and preparation industries.

Supartz (Sodium Hyaluronate) for the Treatment of Knee Osteoarthritis: A Review of Efficacy and Safety

As concerns about the safety of systemic oral pharmacologic treatments for knee osteoarthritis (OA) mount, clinicians have increased the use of intra-articular hyaluronic acid (IA-HA) in managing mild-to-moderate knee OA. Supartz (sodium hyaluronate; Seikagaku Corporation, Tokyo, Japan) is the first IA-HA product to be approved in the world and has the longest history of global use. In this review, we summarize evidence supporting Supartz efficacy and safety, including data from pivotal clinical trials that resulted in approval of Supartz in the United States and Japan, the safety of single and repeated courses of Supartz, and Supartz efficacy using objective outcomes and in special populations. There is strong evidence that single 5-week courses of Supartz provide clinically meaningful reductions in pain and improved function for up to 6 months without risk of serious side effects or complications. Repeated courses of Supartz are as safe as single courses and have an extremely low risk of infection. Findings from promising initial studies, which suggest that Supartz may improve muscle strength, gait pattern, and balance, should be confirmed in randomized controlled trials.

Comparison of Undifferentiated Versus Chondrogenic Predifferentiated Mesenchymal Stem Cells Derived From Human Umbilical Cord Blood for Cartilage Repair in a Rat Model

BACKGROUND

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have gained much interest as a promising cell source for regenerative medicine owing to the noninvasive collection, availability, high expansion capacity, and low immunogenicity. However, few in vivo studies have reported the use of hUCB-MSCs on cartilage repair. Moreover, little study has been conducted on the effects of chondrogenic predifferentiation of hUCB-MSCs on cartilage repair.

PURPOSE

To compare the effectiveness of transplanting undifferentiated versus chondrogenic predifferentiated mesenchymal stem cells (MSCs) for treating osteochondral defects.

STUDY DESIGN

Controlled laboratory study.

METHODS

Critical-sized osteochondral defects were created in the trochlear grooves of rat femurs. In 20 rats, a composite of chondrogenic predifferentiated hUCB-MSCs (chondro-MSCs) and 4% hyaluronic acid (HA) hydrogel was transplanted into defects in the right knees, whereas undifferentiated hUCB-MSCs (undiff-MSCs) and 4% HA hydrogel were transplanted into the left knees. In the control groups, 4% HA hydrogel without MSCs was transplanted into defects in the right knees, and the defects in the left knees were left untreated in 20 rats. The cartilage repair was evaluated at 8 and 16 weeks after surgery.

RESULTS

Transplanting undiff-MSCs resulted in overall superior cartilage repair as compared with chondro-MSCs, HA alone, or no treatment. The articular surfaces of the defect sites in the undiff-MSC group were relatively smoother than those of the other treatments. The undiff-MSC group showed cellular morphology and arrangement similar to surrounding normal articular cartilage tissue at 16 weeks, both of which were also better than those of the other groups. In addition, the undiff-MSC group showed coloration similar to surrounding normal articular cartilage tissue at 16 weeks in safranin O and type II collagen immunohistochemical staining. The histological scores also revealed that cartilage repair with undiff-MSCs was better than that with chondro-MSCs, HA alone, or no treatment ( P < .05 in all).

CONCLUSION

This study demonstrated that treatment with undiff-MSCs resulted in more favorable cartilage repair than that with chondro-MSCs in a rat model. These findings indicate that chondrogenic predifferentiation of MSCs before transplantation does not enhance cartilage repair.

CLINICAL RELEVANCE

The results of this study support the use of undifferentiated MSCs, rather than chondrogenic predifferentiated MSCs, as a stem cell therapy strategy for cartilage repair.

An investigation into the efficacy of intra-articular ozone (O2-O3) injection in patients with knee osteoarthritis: a systematic review and meta-analysis

PURPOSE

This study aimed to review and pool the current literature on intra-articular ozone injection in knee osteoarthritis (OA) patients.

METHODS

A systematic review of three big databases was performed to identify all English-language randomized clinical trials (RCTs) that evaluated the efficacy of intra-articular ozone injection vs a control injection for knee OA sufferers, using the following two measuring tools: pain VAS and Western Ontario and McMaster Universities Arthritis Index (WOMAC).

RESULTS

A total of 428 patients in five RCTs were included, from which 53% (n=225) were in the ozone group and 47% in the control (hyaluronic acid [HA], dextrose, and air injection) group (n=203). The mean age of the patients in both groups was 64 years. Females were the majority. All studies had at least 2 months of follow-up (F/U). Mean difference (MD) between the groups for VAS in the first month was -0.23 with a P-value of 0.71 (negative value was in favor of ozone), whereas this difference in the third and sixth months reached 1.04 and 1.31, respectively, favoring the control group. These data demonstrated that control injection had a more prolonged pain relief period. A similar trend was seen regarding WOMAC scores; pooled results showed that ozone was slightly better than the control injections during the first month (MD =-7.84 [P=0.15]), but it declined to MD=2.55 and 8.23 at 2- to 3- and 4- to 6-month F/U, respectively, again in favor of control injections. Also, adverse events occurred homogeneously in both ozone (6/150 cases, 4%) and control groups (7/129 cases, 5.4%; P-value=0.31).

CONCLUSION

Based on the current meta-analysis, intra-articular ozone injection efficacy was significantly superior to placebo and slightly lower to other control injections with non-significant difference. Therefore, ozone could be recommended as an efficient non-surgical treatment, durable for at least 3-6 months, in mild or moderate knee OA management.

Intra-articular ozone or hyaluronic acid injection: Which one is superior in patients with knee osteoarthritis? A 6-month randomized clinical trial

Purpose

Knee osteoarthritis (OA) is a common disease, imposing a great burden through pain and decreased function. There are many therapeutic modalities including non-pharmacologic choices and oral, topical, and intra-articular medications. New studies have shown promising results for ozone application in knee OA. Our aim was to compare the effects of ozone therapy versus hyaluronic acid (HA) intra-articular injection in knee OA patients.

Methods

In this randomized clinical trial, a total of 174 patients with more than 3 months of chronic pain or swelling in the knee joints along with consistent imaging findings were enrolled and randomly allocated into two groups of HA and ozone, which were planned to undergo 3 weekly injections of HA (Hyalgan®) and 10 mL of a 30 μg/mL ozone solution, respectively. Patients were evaluated at baseline and 6 months after the last injection for pain, stiffness, and function using the visual analog scale (VAS) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire.

Results

No major adverse events were detected in this study. Total WOMAC score decreased from 40.8±9.8 to 20.4±4.9 (p<0.01) in the ozone group and from 38.5±7.9 to 17.1±4.2 (p<0.01) in the HA group. A similar trend was observed in pain improvement according to VAS. Pain, stiffness, and function significantly improved in both the groups, but no between-group difference was found.

Conclusion

Although both ozone and HA can be effectively used for improving function and reducing pain in selected knee OA patients, neither of the two showed any superiority at 6-month follow-up.

Single-stage cell-based cartilage repair in a rabbit model: cell tracking and in vivo chondrogenesis of human umbilical cord blood-derived mesenchymal stem cells and hyaluronic acid hydrogel composite

OBJECTIVE

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have gained popularity as a promising cell source for regenerative medicine, but limited in vivo studies have reported cartilage repair. In addition, the roles of MSCs in cartilage repair are not well-understood. The purpose of this study was to investigate the feasibility of transplanting hUCB-MSCs and hyaluronic acid (HA) hydrogel composite to repair articular cartilage defects in a rabbit model and determine whether the transplanted cells persisted or disappeared from the defect site.

DESIGN

Osteochondral defects were created in the trochlear grooves of the knees. The hUCB-MSCs and HA composite was transplanted into the defect of experimental knees. Control knees were transplanted by HA or left untreated. Animals were sacrificed at 8 and 16 weeks post-transplantation and additionally at 2 and 4 weeks to evaluate the fate of transplanted cells. The repair tissues were evaluated by gross, histological and immunohistochemical analysis.

RESULTS

Transplanting hUCB-MSCs and HA composite resulted in overall superior cartilage repair tissue with better quality than HA alone or no treatment. Cellular architecture and collagen arrangement at 16 weeks were similar to those of surrounding normal articular cartilage tissue. Histological scores also revealed that cartilage repair in experimental knees was better than that in control knees. Immunohistochemical analysis with anti-human nuclear antibody confirmed that the transplanted MSCs disappeared gradually over time.

CONCLUSION

Transplanting hUCB-MSCs and HA composite promote cartilage repair and interactions between hUCB-MSCs and host cells initiated by paracrine action may play an important role in cartilage repair.

Good short- to medium-term results after osteochondral autograft transplantation (OAT) in middle-aged patients with focal, non-traumatic osteochondral lesions of the knee

BACKGROUND

Osteochondral autograft transplantation (OAT) offers the opportunity to repair cartilaginous defects by restoring hyaline cartilage anatomy. Encouraging results have been reported in patients suffering from acute knee trauma or osteochondritis dissecans. Patients with focal chronic, non-traumatic osteochondral (FCNO) lesions of the knee, however, have rarely been the subject of investigation. Some authors even consider higher age as contraindications to OAT.

OBJECTIVES

To assess the short- to medium-term outcomes of OAT in middle-aged patients with FCNO lesions of the knee and to identify predictors of clinical outcome.

HYPOTHESIS

Filling FCNO defects with autologous osteochondral grafts should restore the congruency of the middle-aged knee joint and thereby reduce pain and loss of function on the one hand, and increase quality of life on the other hand.

METHODS

One hundred and twelve patients (48.01±1.12yrs) with FCNO of the knee were assessed before OAT and 26.2±0.24 months after surgery. Clinical outcome was measured by WOMAC Index and the Visual Analogue Scale (VAS) for pain.

RESULTS

Pain (pre-OAT VAS vs. post-OAT VAS: 7.14±0.19 vs. 3.74±0.26, P<0.001) was reduced and quality of life (pre-OAT WOMAC vs. post-OAT WOMAC: 134.88±5.84 vs. 65.92±5.34, P<0.001) improved. Retropatellar defects were associated with poor outcome, while overall surface and number of cylinders were not.

DISCUSSION

Middle-aged patients with FCNO of the knee also profit from OAT at a short follow-up.

LEVEL OF EVIDENCE

IV. Mono-centric, prospective clinical series.

Safety of Repeated Injections of Sodium Hyaluronate (SUPARTZ) for Knee Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

Though there is no consensus on its efficacy, knee osteoarthritis is symptomatically managed with intra-articular hyaluronic acid (IAHA). Recent reports suggest that IAHA may delay the need for total knee replacement, with the magnitude of delay proportional to the number of injection series. However, the safety of repeated injection series is reported to vary between commercial products. This report describes a systematic review of safety data on repeated treatment courses of SUPARTZ.

DESIGN

We performed a systematic search of MEDLINE, Cochrane database, EMBASE, Web of Science, Google Scholar, and unpublished data. We included all human randomized controlled trials or observational studies with adverse event (AE) data for SUPARTZ in knee osteoarthritis. Two independent reviewers extracted data and evaluated study quality. Data were analyzed separately for the first and subsequent series of injections.

RESULTS

The primary sources for repeated-injection data on SUPARTZ were a postmarket registry (N = 7404), 4 prospective studies (N = 127 total), and a retrospective study (N = 220). None of the sources reported increased frequency or severity of AEs with repeated injections. In the registry, 95% of multiple-injection-series patients who reported an AE did so during the first series. None of the AEs was serious, and most resolved spontaneously without medical intervention. The overall adverse event rate after repeat courses of SUPARTZ was 0.008 (95% confidence interval: 0.001-0.055).

CONCLUSIONS

Multiple courses of SUPARTZ injections appear to be at least as safe, and probably safer, than the first course. This study supports the safety of repeat courses of SUPARTZ injections for knee osteoarthritis.

Heterogeneity of Scaffold Biomaterials in Tissue Engineering

Tissue engineering (TE) offers a potential solution for the shortage of transplantable organs and the need for novel methods of tissue repair. Methods of TE have advanced significantly in recent years, but there are challenges to using engineered tissues and organs including but not limited to: biocompatibility, immunogenicity, biodegradation, and toxicity. Analysis of biomaterials used as scaffolds may, however, elucidate how TE can be enhanced. Ideally, biomaterials should closely mimic the characteristics of desired organ, their function and their in vivo environments. A review of biomaterials used in TE highlighted natural polymers, synthetic polymers, and decellularized organs as sources of scaffolding. Studies of discarded organs supported that decellularization offers a remedy to reducing waste of donor organs, but does not yet provide an effective solution to organ demand because it has shown varied success in vivo depending on organ complexity and physiological requirements. Review of polymer-based scaffolds revealed that a composite scaffold formed by copolymerization is more effective than single polymer scaffolds because it allows copolymers to offset disadvantages a single polymer may possess. Selection of biomaterials for use in TE is essential for transplant success. There is not, however, a singular biomaterial that is universally optimal.

A double blind randomized active-controlled clinical trial on the intra-articular use of Md-Knee versus sodium hyaluronate in patients with knee osteoarthritis ("Joint")

Background

To evaluate the clinical outcomes of a group of patients affected by knee osteoarthritis (OA) treated with MD-Knee (Guna S.p.a., Milan, Italy) versus a group of patients treated with sodium hyaluronate.

Method

This non-inferiority prospective randomized controlled trial involved 60 patients affected by knee OA, grade 2–3 of Kellgren-Lawrence scale. The MD-Knee Group, Group A (n = 29) was administered five intra-articular injections at 1 week interval; the sodium hyaluronate Group, Group B (n = 31), was administered five doses of intra-articular injection of sodium hyaluronate at 1 week interval. All patients were prospectively evaluated before and at 3 and 6 months after the treatment by the Lequesne Knee Index (LKI) as primary endpoint and the Visual Analogue Scale (VAS), Pain Killer consumption and SF-36 questionnaires as secondary endpoints.

Results

At the 3- and 6 month follow-up, LKI and VAS improved significantly in both groups compared to baseline and no statistically significant differences were observed between Group A and Group B. There was no statistically significant difference in the SF36 questionnaire score and pain killer consumption between two groups at any time point.

Conclusions

This study shows that both preparations exert similar clinical effects as assessed through multiple outcome measures. MD-Knee is effective on knee OA symptoms over 6 months after a 5-weekly injection course, and it is equally effective as the reference sodium hyaluronate.

Trial registration

Trial registration number: ISRCTN93862496. Registration date: January 18th, 2016

Cartilage Repair Using Composites of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells and Hyaluronic Acid Hydrogel in a Minipig Model

The cartilage regeneration potential of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) with a hyaluronic acid (HA) hydrogel composite has shown remarkable results in rat and rabbit models. The purpose of the present study was to confirm the consistent regenerative potential in a pig model using three different cell lines. A full-thickness chondral injury was intentionally created in the trochlear groove of each knee in 6 minipigs. Three weeks later, an osteochondral defect, 5 mm wide by 10 mm deep, was created, followed by an 8-mm-wide and 5-mm-deep reaming. A mixture (1.5 ml) of hUCB-MSCs (0.5×10(7) cells per milliliter) and 4% HA hydrogel composite was then transplanted into the defect on the right knee. Each cell line was used in two minipigs. The osteochondral defect created in the same manner on the left knee was untreated to act as the control. At 12 weeks postoperatively, the pigs were sacrificed, and the degree of subsequent cartilage regeneration was evaluated by gross and histological analysis. The transplanted knee resulted in superior and more complete hyaline cartilage regeneration compared with the control knee. The cellular characteristics (e.g., cellular proliferation and chondrogenic differentiation capacity) of the hUCB-MSCs influenced the degree of cartilage regeneration potential. This evidence of consistent cartilage regeneration using composites of hUCB-MSCs and HA hydrogel in a large animal model could be a stepping stone to a human clinical trial in the future.

SIGNIFICANCE

To date, several studies have investigated the chondrogenic potential of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs); however, the preclinical studies are still limited in numbers with various results. In parallel, in the past several years, the cartilage regeneration potential of hUCB-MSCs with a hyaluronic acid (HA) hydrogel composite have been investigated and remarkable results in rat and rabbit models have been attained. (These experimental results are currently in preparation for publication.) Before applying the cartilage regeneration technique in a human clinical trial, it seemed necessary to confirm the consistent result in a larger animal model. At 12 weeks postoperatively, the minipigs were sacrificed, and the degree of subsequent cartilage regeneration was evaluated by gross and histological analysis. The transplanted knee resulted in superior and more complete hyaline cartilage regeneration compared with the control knee. This evidence of consistent cartilage regeneration with composites of hUCB-MSCs and HA hydrogel in a large animal model could be a stepping stone to a human clinical trial in the future.

Programmed Application of Transforming Growth Factor β3 and Rac1 Inhibitor NSC23766 Committed Hyaline Cartilage Differentiation of Adipose-Derived Stem Cells for Osteochondral Defect Repair

Hyaline cartilage differentiation is always the challenge with application of stem cells for joint repair. Transforming growth factors (TGFs) and bone morphogenetic proteins can initiate cartilage differentiation but often lead to hypertrophy and calcification, related to abnormal Rac1 activity. In this study, we developed a strategy of programmed application of TGFβ3 and Rac1 inhibitor NSC23766 to commit the hyaline cartilage differentiation of adipose-derived stem cells (ADSCs) for joint cartilage repair. ADSCs were isolated and cultured in a micromass and pellet culture model to evaluate chondrogenic and hypertrophic differentiation. The function of Rac1 was investigated with constitutively active Rac1 mutant and dominant negative Rac1 mutant. The efficacy of ADSCs with programmed application of TGFβ3 and Rac1 inhibitor for cartilage repair was studied in a rat model of osteochondral defects. The results showed that TGFβ3 promoted ADSCs chondro-lineage differentiation and that NSC23766 prevented ADSC-derived chondrocytes from hypertrophy in vitro. The combination of ADSCs, TGFβ3, and NSC23766 promoted quality osteochondral defect repair in rats with much less chondrocytes hypertrophy and significantly higher International Cartilage Repair Society macroscopic and microscopic scores. The findings have illustrated that programmed application of TGFβ3 and Rac1 inhibitor NSC23766 can commit ADSCs to chondro-lineage differentiation and improve the efficacy of ADSCs for cartilage defect repair. These findings suggest a promising stem cell-based strategy for articular cartilage repair.

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Results evaluation of the use of intra-articular sodium hyaluronate in the post-operative knee arthroscopy

OBJECTIVE

to evaluate the efficacy of hyaluronic acid in the post-operative of knee arthroscopy.

METHODS

we have evaluated 49 patients undergoing arthroscopic procedure with the use of intra-articular hyaluronic acid (Group 1) and 49 patients undergoing arthroscopic procedure without the use of hyaluronic acid (Group 2). Patients were evaluated based on the Visual Analogue Scale, household analgesia, assessment of the Range of Motion with a goniometer, and the Lysholm questionnaire.

RESULTS

there were no substantial adverse effects on either group.

CONCLUSION

the use of hyaluronic acid in the post-operative of knee arthroscopy is justified due/because it leads to a decrease in pain in the early stage, enabling faster recovery of the patient.

Intra-articular injection of hyaluronic acid for the reduction in joint adhesion formation in a rabbit model of knee injury

PURPOSE

Our purpose was to evaluate the effectiveness of intra-articular injections of hyaluronic acid (HA) into immobilized joints for reducing rigidity and formation of joint adhesions following surgery and prolonged joint immobilization.

METHODS

Twenty-four New Zealand white rabbits were randomly divided into experimental (n = 12) and control groups (n = 12). A model of knee injury was created in the right hind leg, and external plaster fixation was performed for 8 weeks. The experimental and control groups received weekly intra-articular injections of 0.3 mL HA solution or normal saline, respectively, in the knee joint. The degree of adhesions, range of motion (ROM), and collagen content of the synovium of the knee joint were observed after 8 weeks.

RESULTS

At the end of 8 weeks, the experimental compared with control group had significantly higher mean ROM (70.3° ± 11.1° vs. 54.6° ± 11.2°, respectively; P = 0.002) and mean adhesion score. The experimental group compared with the control group had significantly lower mean adhesion score (2.2 ± 0.9 vs. 3.1 ± 0.7, respectively; P = 0.012) and collagen content (32.4 ± 4.7 vs. 39.0 ± 4.2 μg/mg, P = 0.001).

CONCLUSIONS

In a rabbit model of knee injury, intra-articular injection of HA decreased adhesion formation and collagen content and increased ROM after prolonged immobilization. These results indicate that HA may be clinically useful to prevent adhesions and improve joint mobility in patients who require joint immobilization for up to 8 weeks.

Co-administration of hyaluronic acid with local anaesthetics shows lower cytotoxicity than local anaesthetic treatment alone in bovine articular chondrocytes

OBJECTIVE

To study the effect of hyaluronic acid (HA) on local anaesthetic chondrotoxicity in vitro.

METHODS

Chondrocytes were harvested from bovine femoral condyle cartilage and isolated using collagenase-containing media. At 24 hours after seeding 15 000 cells per well onto a 96-well plate, chondrocytes were treated with media (DMEM/F12 + ITS), PBS, 1:1 lidocaine (2%):PBS, 1:1 bupivacaine (0.5%):PBS, 1:1 lidocaine (2%):HA, 1:1 bupivacaine (0. 5%):HA, or 1:1 HA:PBS for one hour. Following treatment, groups had conditions removed and 24-hour incubation. Cell viability was assessed using PrestoBlue and confirmed visually using fluorescence microscopy.

RESULTS

Media-treated groups had a mean of 1.55×10(4) cells/well (sem 783). All treated cells showed statistically significant reduced viability when compared with media alone (all p < 0.003). Cells treated with bupivacaine + HA (6.70×10(3) cells/well (sem 1.10×10(3))) survived significantly more than bupivacaine (2.44×10(3) cells/well (sem 830)) (p < 0.001). Lidocaine + HA (1.45×10(3) cells/well (sem 596)) was not significantly more cytotoxic than lidocaine (2.24×10(3) cells/well (sem 341)) (p = 0.999). There was no statistical difference between the chondrotoxicities of PBS (8.49×10(3) cells/well (sem 730) cells/well) and HA (4.75×10(3) cells/well (sem 886)) (p = 0.294).

CONCLUSIONS

HA co-administration reduced anaesthetic cytotoxicity with bupivacaine but not lidocaine, suggesting different mechanisms of injury between the two. Co-administered intra-articular injections of HA with bupivacaine, but not lidocaine, may protect articular chondrocytes from local anaesthetic-associated death. Cite this article: Bone Joint Res 2013;2:270-5.

The efficacy of platelet-rich plasma in the treatment of symptomatic knee osteoarthritis: a systematic review with quantitative synthesis

PURPOSE

The purpose of this systematic review was to synthesize the available Level I and Level II literature on platelet-rich plasma (PRP) as a therapeutic intervention in the management of symptomatic knee osteoarthritis (OA).

METHODS

A systematic review of Medline, Embase, Cochrane Central Register of Controlled Trials, PubMed, and www.clinicaltrials.gov was performed to identify all randomized controlled trials and prospective cohort studies that evaluated the clinical efficacy of PRP versus a control injection for knee OA. A random-effects model was used to evaluate the therapeutic effect of PRP at 24 weeks by use of validated outcome measures (Western Ontario and McMaster Universities Arthritis Index, visual analog scale for pain, International Knee Documentation Committee Subjective Knee Evaluation Form, and overall patient satisfaction).

RESULTS

Six Level I and II studies satisfied our inclusion criteria (4 randomized controlled trials and 2 prospective nonrandomized studies). A total of 577 patients were included, with 264 patients (45.8%) in the treatment group (PRP) and 313 patients (54.2%) in the control group (hyaluronic acid [HA] or normal saline solution [NS]). The mean age of patients receiving PRP was 56.1 years (51.5% male patients) compared with 57.1 years (49.5% male patients) for the group receiving HA or NS. Pooled results using the Western Ontario and McMaster Universities Arthritis Index scale (4 studies) showed that PRP was significantly better than HA or NS injections (mean difference, -18.0 [95% confidence interval, -28.8 to -8.3]; P < .001). Similarly, the International Knee Documentation Committee scores (3 studies) favored PRP as a treatment modality (mean difference, 7.9 [95% confidence interval, 3.7 to 12.1]; P < .001). There was no difference in the pooled results for visual analog scale score or overall patient satisfaction. Adverse events occurred more frequently in patients treated with PRP than in those treated with HA/placebo (8.4% v 3.8%, P = .002).

CONCLUSIONS

As compared with HA or NS injection, multiple sequential intra-articular PRP injections may have beneficial effects in the treatment of adult patients with mild to moderate knee OA at approximately 6 months. There appears to be an increased incidence of nonspecific adverse events among patients treated with PRP.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Hyaluronic acid gel injection to prevent thermal injury of adjacent gastrointestinal tract during percutaneous liver radiofrequency ablation

This study evaluated the safety, feasibility, and clinical utility of hyaluronic acid gel injection to separate the gastrointestinal tract from the tumor during liver radiofrequency ablation (RFA). Eleven patients with liver tumors measuring 0.9-3.5 cm (mean ± standard deviation, 2.1 ± 0.8 cm) that were adjacent to the gastrointestinal tracts received RFA after the mixture of hyaluronic acid gel and contrast material (volume, 26.4 ± 14.5 mL; range, 10-60 mL) was injected between the tumor and the gastrointestinal tract under computed tomographic-fluoroscopic guidance. Each tumor was separated from the gastrointestinal tract by 1.0-1.5 cm (distance, 1.2 ± 0.2 cm) after injection of hyaluronic acid gel, and subsequent RFA was performed without any complications in all patients. Although tumor enhancement disappeared in all patients, local tumor progression was found in a patient (9.1%, 1 of 11) during the follow-up of 5.5 ± 3.2 months (range, 0.4-9.9 months). In conclusion, hyaluronic acid gel injection is a safe and useful technique to avoid thermal injury of the adjacent gastrointestinal tract during liver RFA.

Prospects for treating osteoarthritis: enzyme-protein interactions regulating matrix metalloproteinase activity

Primary osteoarthritis (OA) is a musculoskeletal disorder of unknown etiology. OA is characterized by an imbalance between anabolism and catabolism in, and altered homeostasis of articular cartilage. Matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motif are upregulated in OA joints. Extracellular matrix (ECM) proteins are critical for resistance to compressive forces and for maintaining the tensile properties of the tissue. Tissue inhibitor of metalloproteinases (TIMPs) is the endogenous inhibitor of MMPs, but in OA, TIMPs do not effectively neutralize MMP activity. Upregulation of MMP gene expression occurs in OA in a milieu of proinflammatory cytokines such as interleukin (IL)-1, IL-6 and tumor necrosis factor α. Presently, the medical therapy of OA includes mainly nonsteroidal anti-inflammatory drugs and corticosteroids which dampen pain and inflammation but appear to have little effect on restoring joint function. Experimental interventions to restore the imbalance between anabolism and catabolism include small molecule inhibitors of MMP subtypes or inhibitors of the interaction between IL-1 and its receptor. Although these agents have some positive effects on reducing MMP subtype activity they have little efficacy at the clinical level. MMP-9 is one MMP subtype implicated in the degradation of articular cartilage ECM proteins. MMP-9 was found in OA synovial fluid as a complex with neutrophil gelatinase-associated lipocalin (NGAL) which protected MMP-9 from autodegradation. Suppressing NGAL synthesis or promoting NGAL degradation may result in reducing the activity of MMP-9. We also propose initiating a search for enzyme-protein interactions to dampen other MMP subtype activity which could suppress ECM protein breakdown.

Inflammation and Joint Tissue Interactions in OA: Implications for Potential Therapeutic Approaches

It is increasingly recognized that the pathogenesis of cartilage degradation in osteoarthritis (OA) is multifactorial and involves the interactions between cartilage and its surrounding tissues. These interactions regulate proinflammatory cytokine-mediated cartilage destruction, contributing to OA progression as well as cartilage repair. This review explores the pathogenesis of OA in the context of the multiple tissue types in the joint and discusses the implications of such complex tissue interaction in the development of anti-inflammatory therapeutics for the treatment of OA.

Genome integrity, stem cells and hyaluronan

Faithful preservation of genome integrity is the critical mission of stem cells as well as of germ cells. Reviewed are the following mechanisms involved in protecting DNA in these cells: (a) The efflux machinery that can pump out variety of genotoxins in ATP-dependent manner; (b) the mechanisms maintaining minimal metabolic activity which reduces generation of reactive oxidants, by-products of aerobic respiration; (c) the role of hypoxic niche of stem cells providing a gradient of variable oxygen tension; (d)(e) the presence of hyaluronan (HA) and HA receptors on stem cells and in the niche; (f) the role of role of HA in protecting DNA from oxidative damage; (g) the specific role of HA that may play a role protecting DNA in stem cells; (h) the interactions of HA with sperm cells and oocytes that also may shield their DNA from oxidative damage, and (e) mechanisms by which HA exerts the anti-oxidant activity. While HA has multitude of functions its anti-oxidant capabilities are often overlooked but may be of significance in preservation of integrity of stem and germ cells genome.