Clinical, biochemical, and histologic effects of intra-articular administration of autologous conditioned serum in horses with experimentally induced osteoarthritis

Is there a role for autologous conditioned serum injections in osteoarthritis? A systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To assess whether patient reported outcome measures (PROMs) improve after autologous conditioned serum (ACS) administration in patients with osteoarthritis.

METHODS

Databases and clinical trial registers were searched to March 2024 for randomised controlled trial (RCTs) comparing ACS vs comparators/controls. Primary outcomes were pain, function and stiffness measured with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and visual analogue scale (VAS). Secondary outcome was complications. Risk of bias (RoB) and certainty of evidence were assessed using RoB 2 and the Grades of Recommendation, Assessment, Development and Evaluation Working Group (GRADE) respectively. Meta-analysis was undertaken using RevMan v5.4. Results are presented as standardised mean differences (SMD) or mean differences (MD) with 95% confidence intervals (CI). Sensitivity analysis compared all comparators and saline control.

RESULTS

Five RCTs were identified (n = 741 participants); two (n = 529 participants) compared ACS against saline (placebo). Three studies were "some concern" and two studies "high risk" for bias. Analysis comparing ACS with all comparators significantly favoured ACS at 6 months for WOMAC: SMD -0.61 (95% CI -1.01 to -0.21; p = 0.003); and VAS: SMD -1.24 (95% CI -2.11 to -0.38; p = 0.005); with high heterogeneity. Comparing ACS with saline, there was no significant difference in WOMAC or VAS at 6 months: SMD -0.40 (95% CI -0.93 to 0.12; p = 0.13) and MD -9.87 (95% CI -27.73 to 7.98, p = 0.28). Complications were similar: ACS (24.8%) vs saline (24.4%), with serious complications rare.

CONCLUSION

There is currently insufficient data to support the use of ACS in osteoarthritis with conflicting results when compared to alternative therapies and saline control, with high heterogeneity. Before consideration as a potential treatment, a high-quality multicentre RCT is required to assess the efficacy of ACS.

Conservative management of spinal pathology with autologous conditioned serum: A systematic review of the literature

BACKGROUND

Chronic inflammatory pain is associated with increased expression of interleukin (IL)-1, an inflammatory cytokine, and activity on its receptor (IL-1R). In response, the body produces IL-1R antagonist (IL-1Ra) to reduce this signaling. Autologous conditioned serum (ACS) is the only biologic therapy for spinal pathologies that enhances the action of endogenous IL-1Ra reserves to improve symptoms. This systematic review investigates the effectiveness of ACS in treating pain and disability caused by spinal pathologies.

AIM

To evaluate the use of ACS as a conservative management option for spinal pathology.

METHODS

A systematic review of PubMed/Medline was performed to identify studies investigating administration of ACS for treatment of any spinal pathology.

RESULTS

Six articles were included, comprising 684 patients treated with epidural (n = 133) or transforaminal (n = 551) ACS injections. Patients had an average age of 54.0 years with slight female predominance (53.2%). The lumbar spine was most commonly treated, with 567 patients (82.9%) receiving injections for lumbar radiculopathy (n = 67), degenerative disc disease (DDD) (n = 372), or spinal stenosis (n = 128); cervical injections were performed in 109 patients (15.9%). Mean (SD) follow-up was 21.7 (4.8) weeks from first ACS injection. All studies investigating mechanical lumbar and lumbar or cervical radicular pain reported significant pain reduction at final follow-up compared to baseline. ACS achieved comparable or superior results to lumbar epidural steroid injections. Adverse events were reported in 21 patients (3.1%), with no serious adverse events.

CONCLUSION

ACS injection is a safe and effective intervention for pain reduction in many spinal pathologies, including cervical and lumbar radiculopathies.

Platelet-Rich Plasma and Related Orthobiologics for the Treatment of Equine Musculoskeletal Disorders-A Bibliometric Analysis from 2000 to 2024

(1) Background: There is increasing interest in the use of platelet-rich plasma and related orthobiologics for the treatment of chronic musculoskeletal disorders in horses; however, there is no information on the bibliometric impact of the literature published in this area. (2) Methods: A bibliometric analysis was performed using the bibliometrix R package by analyzing the documents registered in the WOS and Scopus databases from 2000 to 2024. The included registers were evaluated according to the menu of results from the biblioshiny web app (overview, sources, authors, documents, words, trending topics, clustering, conceptual structure, and social structure). (3) Conclusions: The documents produced were mainly published in Frontiers in Veterinary Science, Journal of Equine Veterinary Science, BMC Veterinary Research, and the American Journal of Veterinary Research). The most productive institutions were Universidad de Caldas, Colorado State University, University of California-Davis, and University of Leipzig, and the most productive countries were the USA, Brazil, and Colombia. Horse, platelet-rich plasma, equine, osteoarthritis, and autologous conditioned serum were the most frequently used keywords. The trending topics in this area are platelet lysates and orthobiologics. The collaboration network of authors, institutions, and countries shows an isolated development of individual author networks with modest collaboration between institutions and countries.

Current Non-Surgical Curative Regenerative Therapies for Knee Osteoarthritis

Osteoarthritis (OA) is a prevalent musculoskeletal disease affecting middle-aged and elderly individuals, with knee pain as a common complaint. Standard therapy approaches generally attempt to alleviate pain and inflammation, using various pharmacological and non-pharmacological options. However, the efficacy of these therapies in long-term tissue repair remains debated. As an alternative, regenerative medicine offers a promising strategy, with decreased adverse event rates and increasing evidence of safety and efficacy. This review will outline current advances in regenerative medicine for knee OA, emphasizing outpatient clinic-based therapies that use orthobiological and non-biological products. Different strategies based on orthobiologics are discussed as potential regenerative options for the management of knee OA. Cell-free therapies including platelet-rich plasma, autologous anti-inflammatories, exosomes, human placenta extract, and mitochondrial transplantation are discussed, focusing on their potential for cartilage regeneration. Additionally, cell-based therapies with regenerative properties including bone marrow aspirate concentrate, adipose stromal vascular fraction, microfat, nanofat, stem cell therapy, and genetically modified cells as part of orthobiologics, are being investigated. Also, this study is looking into non-biological approaches such as using gold-induced cytokines, extracorporeal shockwave therapy, and ozone therapy. The mechanisms of action, effectiveness, and clinical applications of each therapy are being explored, providing insights into their role in the management of knee OA.

Animal Models of Osteoarthritis: Updated Models and Outcome Measures 2016-2023

Purpose

Osteoarthritis (OA) is a global musculoskeletal disorder that affects primarily the knee and hip joints without any FDA-approved disease-modifying therapies. Animal models are essential research tools in developing therapies for OA; many animal studies have provided data for the initiation of human clinical trials. Despite this, there is still a need for strategies to recapitulate the human experience using animal models to better develop treatments and understand pathogenesis. Since our last review on animal models of osteoarthritis in 2016, there have been exciting updates in OA research and models. The main purpose of this review is to update the latest animal models and key features of studies in OA research.

Method

We used our existing classification method and screened articles in PubMed and bibliographic search for animal OA models between 2016 and 2023. Relevant and high-cited articles were chosen for inclusion in this narrative review.

Results

Recent studies were analyzed and classified. We also identified ex vivo models as an area of ongoing research. Each animal model offers its own benefit in the study of OA and there are a full range of outcome measures that can be assessed. Despite the vast number of models, each has its drawbacks that have limited translating approved therapies for human use.

Conclusion

Depending on the outcome measures and objective of the study, researchers should pick the best model for their work. There have been several exciting studies since 2016 that have taken advantage of regenerative engineering techniques to develop therapies and better understand OA.

Lay Summary

Osteoarthritis (OA) is a chronic debilitating disease without any cure that affects mostly the knee and hip joints and often results in surgical joint replacement. Cartilage protects the joint from mechanical forces and degrades with age or in response to injury. The many contributing causes of OA are still being investigated, and animals are used for preclinical research and to test potential new treatments. A single consensus OA animal model for preclinical studies is non-existent. In this article, we review the many animal models for OA and provide a much-needed update on studies and model development since 2016.

Evaluation of the efficacy of autologous conditioned serum versus dextrose prolotherapy in internal derangement of the TMJ - A pilot study

It was the aim of the study to compare the effectiveness of autologous conditioned serum (ACS) and dextrose prolotherapy (DP) solutions, in treating patients with TMJ internal derangement (ID). 24 participants with TMJ ID (Wilkes II-V) were recruited and randomized into study and control groups, with 12 patients each, treated with IA injection of ACS and DP, respectively. Pain, mouth opening, joint sounds, and jaw deviation were evaluated, with patients reviewed at 2 weeks, 1 month, and 2 months intervals. Based on the nature of the variables, appropriate descriptive statistics and statistical tests were applied. The pain score was zero in the study group after 2 months of treatment, which was statistically significant (p = 0.006). Deviation was also significantly reduced (p < 0.001) and mouth opening significantly improved (p = 0.004) in the ACS-treated patients. ACS demonstrated superiority over DP in the management of TMJ dysfunction. Therefore, ACS can be considered an ideal, minimally invasive treatment option for TMJ ID. Clinical trial registry number: (CTRI/2021/10/037043).

Intraarticular treatment with integrin α10β1-selected mesenchymal stem cells affects microRNA expression in experimental post-traumatic osteoarthritis in horses

Osteoarthritis (OA) remains a major cause of lameness in horses, which leads to lost days of training and early retirement. Still, the underlying pathological processes are poorly understood. MicroRNAs (miRNAs) are small non-coding RNAs that serve as regulators of many biological processes including OA. Analysis of miRNA expression in diseased joint tissues such as cartilage and synovial membrane may help to elucidate OA pathology. Since integrin α10β1-selected mesenchymal stem cell (integrin α10-MSC) have shown mitigating effect on equine OA we here investigated the effect of integrin α10-MSCs on miRNA expression. Cartilage and synovial membrane was harvested from the middle carpal joint of horses with experimentally induced, untreated OA, horses with experimentally induced OA treated with allogeneic adipose-derived MSCs selected for the marker integrin α10-MSCs, and from healthy control joints. miRNA expression in cartilage and synovial membrane was established by quantifying 70 pre-determined miRNAs by qPCR. Differential expression of the miRNAs was evaluated by comparing untreated OA and control, untreated OA and MSC-treated OA, and joints with high and low pathology score. A total of 60 miRNAs were successfully quantified in the cartilage samples and 55 miRNAs were quantified in the synovial membrane samples. In cartilage, miR-146a, miR-150 and miR-409 had significantly higher expression in untreated OA joints than in control joints. Expression of miR-125a-3p, miR-150, miR-200c, and miR-499-5p was significantly reduced in cartilage from MSC-treated OA joints compared to the untreated OA joints. Expression of miR-139-5p, miR-150, miR-182-5p, miR-200a, miR-378, miR-409-3p, and miR-7177b in articular cartilage reflected pathology score. Several of these miRNAs are known from research in human patients with OA and from murine OA models. Our study shows that these miRNAs are also differentially expressed in experimental equine OA, and that expression depends on OA severity. Moreover, MSC treatment, which resulted in less severe OA, also affected miRNA expression in cartilage.

Allogeneic chondrogenic-induced mesenchymal stem cells for the treatment of tarsometatarsal lameness in horses

OBJECTIVE

To assess the efficacy of commercial intra-articular blood-derived allogeneic-induced mesenchymal stem cells (CIMSCs) to treat tarsometatarsal lameness in horses.

STUDY DESIGN

This was a retrospective cohort study.

ANIMALS

Records from 167 adult light breed horses with bilateral tarsometatarsal lameness.

METHODS

Horses with tarsometatarsal lameness were retrospectively selected from medical records. Diagnosis followed subjective graded lameness assessment before and after intra-articular analgesia, with graded radiographic tarsal examination. Horses were excluded if they were diagnosed or treated for any other concurrent lameness conditions during the study. Time to last follow-up and time of recurrence of lameness was recorded at veterinary re-assessment.

RESULTS

A total of 67 horses were recruited to the CIMSC-treated group and 100 to the corticosteroid (CS)-treated group. Median age was 9 years, with no difference in signalment, use or radiographic grade between groups. First re-examination was 38 days (95% CI: 38-49), with no difference between groups, CIMSC 42 (35-45), control 34 (25-42). Median follow-up was 438 days for CIMSC, 546 for controls. Symptoms of lameness recurred in 86/100 controls compared to 17/67 (25%) CIMSC. Median time to lameness recurring in CIMSC was 336 days (95% CI: 239-400), control 90 days (95% CI: 80-108), p < .0001. Cox proportional hazard ratio for treatment was 8.35, 95% CI: 4.67 to 14.92, p < .0001.

CONCLUSIONS

Lameness was abolished in all treated horses. It recurred significantly less often, and later, in CIMSC-treated horses.

CLINICAL SIGNIFICANCE

Intra-articular CIMSC treatment results in prolonged soundness in horses with tarsometatarsal lameness.

Use of Autologous Conditioned Serum (ACS) for Osteoarthritis Treatment in Horses: A Systematic Review of Clinical Data

The utilization of Autologous Conditioned Serum (ACS) for treating osteoarthritis (OA) in horses has seen a notable increase in recent years. In vitro studies have consistently identified ACS as a promising therapy for OA joints, contributing to its growing popularity in OA treatment. Despite this, there is a noticeable absence of systematic reviews focused solely on the clinical data of OA patients treated with ACS, excluding the in vitro perspective. This study aims to address this gap by systematically reviewing the latest literature, concentrating solely on clinical data in in vivo studies to evaluate the efficacy of ACS in OA lesions. All clinical studies involving ACS treatments for horses with OA were included in the assessment. Surprisingly, only six trials met the inclusion criteria for this systematic review. The results indicate that the majority of the considered articles support the use of ACS as a treatment for horses, albeit with a control group provided in only one study. However, the absence of a control group and the exclusion of histological evaluation diminish the validity of the majority of clinical research. While several studies suggest a beneficial effect of ACS on OA horses without significant adverse effects, this systematic review affirms that there is no definitive evidence for its effectiveness. Therefore, further investigation of the efficacy of ACS products as a treatment for OA is warranted, emphasizing the need for more controlled trials. Poorly designed and biased studies, lacking blinding or control and adopting inadequate outcome measures, may favor positive results and, thus, necessitate a more rigorous approach to validate the efficacy of ACS in OA treatment.

Equine Autologous Conditioned Serum and Autologous Protein Solution

Orthobiologics are used with increasing frequency in equine musculoskeletal disease to improve the quality of the repair tissue and prevent reinjury. Autologous blood-based products, or hemoderivatives, are made by processing the patient's blood using different systems to produce a final therapeutic product. Autologous conditioned serum (ACS) and autologous protein solution (APS) are commonly used to treat joint disorders and can also be used treat tendon and ligament injuries. Hemoderivatives contain increased concentrations of anti-inflammatory and immunomodulatory cytokines, and growth factors that help direct tissue healing and repair. The specifics of ACS and APS for treatment of musculoskeletal injuries are discussed.

A pilot study to determine the optimal dose of scAAVIL-1ra in a large animal model of post-traumatic osteoarthritis

Gene therapy approaches using adeno-associated viral vectors have been successfully tested in the equine post-traumatic osteoarthritis (PTOA) model. Owing to differences in the levels of transgene expression and adverse tissue reactions observed in published studies, we sought to identify a safe therapeutic dose of scAAVIL-1ra in an inflamed and injured joint that would result in improved functional outcomes without any adverse events. scAAVIL-1ra was delivered intra-articularly over a 100-fold range, and horses were evaluated throughout and at the end of the 10-week study. A dose-related increase in IL-1ra levels with a decrease in PGE2 levels was observed, with the peak IL-1ra concentration being observed 7 days post-treatment in all groups. Perivascular infiltration with mononuclear cells was observed within the synovial membrane of the joint treated with the highest viral dose of 5 × 1012 vg, but this was absent in the lower-dosed joints. The second-highest dose of scAAVeqIL-1ra 5 × 1011 vg demonstrated elevated IL-1ra levels without any cellular response in the synovium. Taken together, the data suggest that the 10-fold lower dose of 5 × 1011vg scAAVIL-1ra would be a safe therapeutic dose in an equine model of PTOA.

Integrin α10β1-Selected Mesenchymal Stem Cells Reduce Pain and Cartilage Degradation and Increase Immunomodulation in an Equine Osteoarthritis Model

OBJECTIVE

Integrin α10β1-selected mesenchymal stem cells (integrin α10-MSCs) have previously shown potential in treating cartilage damage and osteoarthritis (OA) in vitro and in animal models in vivo. The aim of this study was to further investigate disease-modifying effects of integrin α10-MSCs.

DESIGN

OA was surgically induced in 17 horses. Eighteen days after surgery, horses received 2 × 107 integrin α10-MSCs intra-articularly or were left untreated. Lameness and response to carpal flexion was assessed weekly along with synovial fluid (SF) analysis. On day 52 after treatment, horses were euthanized, and carpi were evaluated by computed tomography (CT), MRI, histology, and for macroscopic pathology and integrin α10-MSCs were traced in the joint tissues.

RESULTS

Lameness and response to carpal flexion significantly improved over time following integrin α10-MSC treatment. Treated horses had milder macroscopic cartilage pathology and lower cartilage histology scores than the untreated group. Prostaglandin E2 and interleukin-10 increased in the SF after integrin α10-MSC injection. Integrin α10-MSCs were found in SF from treated horses up to day 17 after treatment, and in the articular cartilage and subchondral bone from 5 of 8 treated horses after euthanasia at 52 days after treatment. The integrin α10-MSC injection did not cause joint flare.

CONCLUSION

This study demonstrates that intra-articular (IA) injection of integrin α10-MSCs appears to be safe, alleviate pathological changes in the joint, and improve joint function in an equine post-traumatic osteoarthritis (PTOA) model. The results suggest that integrin α10-MSCs hold promise as a disease-modifying osteoarthritis drug (DMOAD).

Intra-articular bone marrow mononuclear cell therapy improves lameness from naturally occurring equine osteoarthritis

Osteoarthritis (OA) can be debilitating and is related to impaired resolution of synovial inflammation. Current treatments offer temporary relief of clinical signs, but have potentially deleterious side effects. Bone marrow mononuclear cells (BMNC) are a rich source of macrophage progenitors that have the ability to reduce OA symptoms in people and inflammation in experimentally-induced synovitis in horses. The objective of this study was to evaluate the ability of intra-articular BMNC therapy to improve clinical signs of naturally occurring equine OA. Horses presenting with clinical and radiographic evidence of moderate OA in a single joint were randomly assigned to 1 of 3 treatment groups: saline (negative control), triamcinolone (positive control), or BMNC (treatment group). Lameness was evaluated subjectively and objectively, joint circumference measured, and synovial fluid collected for cytology and growth factor/cytokine quantification at 0, 7, and 21 days post-injection. Data were analyzed using General Estimating Equations with significance set at p < 0.05. There were no adverse effects noted in any treatment group. There was a significant increase in synovial fluid total nucleated cell count in the BMNC-treated group on day 7 (median 440; range 20-1920 cells/uL) compared to day 0. Mononuclear cells were the predominant cell type across treatments at all time points. Joint circumference decreased significantly in the BMNC-treated group from days 7 to 21 and was significantly lower at day 21 in the BMNC-treated group compared to the saline-treated group. Median objective lameness improved significantly in the BMNC group between days 7 and 21. GM-CSF, IL-1ra, IGF-1, and TNF-α were below detectable limits and IL-6, IL-1β, FGF-2 were detectable in a limited number of synovial fluid samples. Inconsistent and limited differences were detected over time and between treatment groups for synovial fluid PGE2, SDF-1, MCP-1 and IL-10. Decreased lameness and joint circumference, coupled with a lack of adverse effects following BMNC treatment, support a larger clinical trial using BMNC therapy to treat OA in horses.

The effect of exercise on cytokine concentration in equine autologous conditioned serum

BACKGROUND

Autologous conditioned serum (ACS) is a commonly administered intra-articular treatment for the management of osteoarthritis in athletic horses.

OBJECTIVES

To investigate the influence of exercise on the concentration of cytokines in a non-commercial method of ACS production.

STUDY DESIGN

Non-randomised cross over design.

METHODS

Whole blood was obtained from eight healthy Standardbred horses immediately prior to, 1 h and 24 h following a single bout of exhaustive exercise. Blood was processed using a non-commercial method of ACS production. Fluorescent microsphere immunoassay (FMIA) analysis was performed to quantify Interleukin 1 receptor antagonist (IL-1Ra), Interleukin-10 (IL-10), Interleukin 1β (IL-1β) and tumour necrosis factor α (TNF-α) concentrations at each time point. Mixed effect repeated measures analysis of variance (ANOVA) was used to compare the pre-exercise and post-exercise cytokine concentrations. Significance was set at P < 0.05.

RESULTS

A reduced concentration of IL-1Ra (median 584.4, IQR 81.9-5098 pg/ml, p = 0.004) and an increased concentration of TNF-α (11.92, 9.28-39.75 pg/ml, P = .05) at 1 h post-exercise were observed when compared with baseline values (IL-Ra 7349, 1272-10 760 pg/ml; TNF TNF-α 11.16, 8.36-32.74 pg/ml). No difference in cytokine concentrations of IL-10 or IL-1β were found between any of the time points.

MAIN LIMITATIONS

The large biological variability and small sample size represents limitations of this study.

CONCLUSIONS

These results suggest that a single bout of intense exercise can reduce the concentration of the anti-inflammatory cytokine IL-1Ra and increase the concentration of the pro-inflammatory cytokine TNF-α, reducing the 'anti-inflammatory' cytokine composition of ACS. Our findings suggest that collection of blood for ACS production should be performed no sooner than 24 h following a single episode of intense exercise.

Conditioned serum in vitro treatment of chondrocyte pellets and osteoarthritic explants

BACKGROUND

Autologous conditioned serum (ACS) is used to treat osteoarthritis in horses, although its effects are not fully investigated.

OBJECTIVES

To investigate the effects of equine serum and conditioned serum on chondrocytes stimulated with interleukin (IL)-1β and cartilage explants with mild osteoarthritis.

STUDY DESIGN

In vitro experimental study.

METHODS

The effect of three different serum preparations (unincubated control [PS], serum incubated 24 h [PS24h] and serum incubated 24 h in ACS containers [PCS]) pooled from lame horses were tested in two in vitro models. IL-1β and IL-1 receptor antagonist (IL-1Ra) concentrations were measured in all sera. In model 1, chondrocyte pellet cultures were stimulated with IL-1β prior to treatment with the serum preparations for 2 and 48 h. Microarray, polymerase chain reaction, and matrix metallopeptidase-13 analyses were performed. In model 2, cartilage explants from horses with structural osteoarthritis were treated with PS or PCS on days 0, 6 and 12, or left untreated, and evaluated at day 24 using the OARSI grading scale for histological evaluation of articular cartilage.

RESULTS

The IL-1Ra concentration in PS24h and PCS was significantly higher than in PS. In model 1, inflammation- and cartilage matrix degradation-related genes were upregulated after 48 h in all treatment groups versus untreated controls. Cartilage matrix molecules, aggrecan and collagens, were downregulated in PS24h- and PCS-treated pellets versus untreated controls. Growth factor signalling genes were upregulated-FGF7 in all treatment groups, BMP2 in PS24h-, and INHBA in PCS-treated-compared with untreated controls. In model 2, the OARSI score at day 24 was not significantly different between treatment groups.

MAIN LIMITATIONS

Results from in vitro models cannot be directly translated to in vivo situations.

CONCLUSIONS

In vitro treatment with conditioned serum did not alleviate IL-1β-induced responses in chondrocyte pellets or lead to morphological improvement in osteoarthritic cartilage explants.

Icariin-conditioned serum combined with chitosan attenuates cartilage injury in rabbit knees with osteochondral defect

BACKGROUND

Knee osteoarthritis (KOA) is one of the most common degenerative diseases. Its development is closely related to cartilage injury and subchondral bone remodeling homeostasis. In the present study, we combined icariin-conditioned serum (ICS) with thiolated chitosan (CSSH), a material widely used in tissue engineering for cartilage repair, to demonstrate its effect on the repair of cartilage damage and abnormal subchondral remodeling.

METHODS

New Zealand rabbits were undergoing surgery for cartilage defect, and joint cavity injection was performed in each group with 0.5 mL normal saline (NS), ICS, CSSH and ICS-CSSH in the right joint every week for five times. Positioning performance was observed using VICON motion capture system. Glycosaminoglycans (GAG) secretion of articular fluid was assessed. Osteoarthritis Research Society International (OARSI) score and immunohistochemical (IHC) analysis including H&E, Safranin O and collagen II staining were employed to evaluate the morphologic repair of cartilage and subchondral bone. mRNA expression of COL2A1, MMP13 and ADAMTS5 was detected in chondrocytes from injury area.

RESULTS

ICS combined with CSSH attenuated cartilage injury and abnormal subchondral remodeling in rabbits with KOA. ICS and CSSH groups showed slight improvement in positioning performance, while ICS-CSSH group exhibited better positioning performance. ICS-CSSH group showed increased GAG secretion of articular fluid and expression of COL2A1 in articular chondrocytes. Furthermore, both macroscopic observation and IHC analysis showed femoral condyle in ICS-CSSH rabbits were repaired with more native cartilage and subchondral bone regeneration.

CONCLUSIONS

ICS combined with CSSH could promote the repair of osteochondral defect and stabilize subchondral bone remodeling in rabbit knees.

Distinct differences in immunological properties of equine orthobiologics revealed by functional and transcriptomic analysis using an activated macrophage readout system

Introduction

Multiple biological therapies for orthopedic injuries are marketed to veterinarians, despite a lack of rigorous comparative biological activity data to guide informed decisions in selecting a most effective compound. Therefore, the goal of this study was to use relevant bioassay systems to directly compare the anti-inflammatory and immunomodulatory activity of three commonly used orthobiological therapies (OTs): mesenchymal stromal cells (MSC), autologous conditioned serum (ACS), and platelet rich plasma (PRP).

Methods

Equine monocyte-derived macrophages were used as the readout system to compare therapies, including cytokine production and transcriptomic responses. Macrophages were stimulated with IL-1ß and treated 24 h with OTs, washed and cultured an additional 24 h to generate supernatants. Secreted cytokines were measured by multiplex immunoassay and ELISA. To assess global transcriptomic responses to treatments, RNA was extracted from macrophages and subjected to full RNA sequencing, using an Illumina-based platform. Data analysis included comparison of differentially expressed genes and pathway analysis in treated vs. untreated macrophages.

Results

All treatments reduced production of IL-1ß by macrophages. Secretion of IL-10 was highest in MSC-CM treated macrophages, while PRP lysate and ACS resulted in greater downregulation of IL-6 and IP-10. Transcriptomic analysis revealed that ACS triggered multiple inflammatory response pathways in macrophages based on GSEA, while MSC generated significant downregulation of inflammatory pathways, and PRP lysate induced a mixed immune response profile. Key downregulated genes in MSC-treated cultures included type 1 and type 2 interferon response, TNF-α and IL-6. PRP lysate cultures demonstrated downregulation of inflammation-related genes IL-1RA, SLAMF9, ENSECAG00000022247 but concurrent upregulation of TNF-α, IL-2 signaling, and Myc targets. ACS induced upregulation of inflammatory IL-2 signaling, TNFα and KRAS signaling and hypoxia, but downregulation of MTOR signaling and type 1 interferon signaling.

Discussion

These findings, representing the first comprehensive look at immune response pathways for popular equine OTs, reveal distinct differences between therapies. These studies address a critical gap in our understanding of the relative immunomodulatory properties of regenerative therapies commonly used in equine practice to treat musculoskeletal disease and will serve as a platform from which further in vivo comparisons may build.

Systematic review and meta-analysis of positive long-term effects after intra-articular administration of orthobiologic therapeutics in horses with naturally occurring osteoarthritis

Equine veterinarians face challenges in treating horses with osteoarthritic joint pain in routine veterinary practice. All common treatment options aim to reduce the clinical consequences of osteoarthritis (OA) characterized by persistent synovitis and progressive degradation of articular cartilage. A range of joint-associated cell types and extracellular matrices are involved in the not yet entirely understood chronic inflammatory process. Regeneration of articular tissues to re-establish joint hemostasis is the future perspective when fundamental healing of OA is the long-term goal. The use of intra-articular applied biologic therapeutics derived from blood or mesenchymal stroma cell (MSC) sources is nowadays a well-accepted treatment option. Although this group of therapeutics is not totally consistent due to the lack of clear definitions and compositions, they all share a potential regenerative effect on articular tissues as described in in vivo and in vitro studies. However, the current stage of science in regenerative medicine needs to be supported by clinical reports as in fact, in vitro studies as well as studies using induced OA models still represent a fragment of the complex pathomechanism of naturally occurring OA. This systemic review aims to determine the long-term effect of orthobiologic therapeutics in horses suffering naturally occurring OA. Thereby, a meta-analysis of randomized controlled trials (RCTs) is conducted to describe the efficiency and safety of intra-articular applied orthobiologics in terms of lameness reduction in the long-term. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, thirteen studies met the inclusion criteria for the systemic review. Four of those studies have further been evaluated by the meta-analysis comparing the long-term effect in lameness reduction. Each study was examined for risk of bias. For data evaluation, a random-effects model was used, describing the overall outcome in a forest plot. The I² statistic was used to assess heterogeneity. Results indicate, that orthobiologic therapies represent an effective long-term and safe OA treatment option. Due to the inhomogeneity of included studies, no statements are provided addressing specific orthobiologic therapies, affected joints, OA stage and horse's intended use. Future clinical trials should follow standardized study designs to provide comparable data.

In Vitro Anti-Inflammatory and Regenerative Effects of Autologous Conditioned Serum from Dogs with Osteoarthritis

Osteoarthritis (OA) is mostly incurable and non-regenerative with long-term complications. Autologous conditioned serum (ACS), which is enriched in Interleukin 1 receptor antagonists (IL-1RA) and growth factors, could be an alternative treatment to accelerate the positive therapeutic effects. ACS is proposed to alleviate inflammation by blocking IL-1 receptors. However, to date, there is no report focusing on the cell-mediated anti-inflammation and regenerative effect caused by ACS, especially the ACS from patients. Therefore, this study aims to investigate the therapeutic potential of ACS generated from dogs with spontaneous OA, focusing on its promising anti-inflammatory and regenerative properties in vitro compared to the matched plasma. We found that ACS prepared from ten OA dogs contained significant concentrations of IL-1RA, vascular endothelial growth factor, and transforming growth factor beta, which are key cytokines in anti-inflammation and angiogenesis. Furthermore, we found that ACS suppressed T cell activity by reducing proliferation of effector T cells and simultaneously expanding numbers of immune suppressive FOXP3+ T cells. Lastly, we showed that ACS enhanced the proliferation of osteocytes and fibroblasts and promoted extracellular matrix gene expression in primary chondrocyte culture. Therefore, these studies indicate that ACS prepared from dogs with OA is active as an immunomodulatory and regenerative strategy for use in OA management.

The therapeutic effects of autologous conditioned serum on knee osteoarthritis: an animal model

Objective

As a progressive chronic condition, osteoarthritis (OA) causes substantial pain and impairment. Secrete proinflammatory cytokines are essential mediators involved in the pathophysiology of OA. In this regard, the clinical effectiveness of autologous conditioned serum (ASC) has been shown through its injection into OA tissues. This study aimed to assess the effectiveness and concentration level of ACS components produced by Nano-carbon glass beads.

Intravenous whole blood was obtained from each New Zealand male rabbit by 10-ml syringes, comprising 33 medical-grade Nano carbon-coated glass beads. Serum retrieving was performed after 6–8 h incubation (37 C, 5% Co₂), and then centrifuged. The ACS was then injected into OA rabbits to assess its function.

Results

Glass beads-prepared ACS coated with Nano-carbon, induced a huge amount of cytokines and growth factors production. The concentration level of anti-inflammatory cytokines and proinflammatory cytokines was improved throughout Nano-carbon coated glass beads stimulation. ACS also shortened the recovery time and improved the function and mobility of OA rabbits.

We showed that ACS improved the function and mobility of OA rabbits, as well as shortened the recovery time. It is suggested that further studies evaluate this effectiveness.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06166-1.

Use of allogeneic freeze-dried conditioned serum for the prevention of degradation in cartilage exposed to IL-1ß

Background

Autologous conditioned serum (ACS) has been extensively used in the field of veterinary orthopaedics and sports medicine. Due to the autologous and blood-derived nature of this product, issues such as individual variability, need for storage at low temperatures and non-availability for immediate are frequently encountered for ACS use in the field. To address those issues, we proposed the evaluation of an off-the-shelf allogeneic freeze-dried version of conditioned serum in an in vitro model of osteoarthritis. In this study, we evaluated if origin (autologous and allogeneic) and preparation (frozen and freeze-dried) of conditioned serum could influence in its effect in an in vitro model.

Results

IL-1β stimulation in cartilage led to a significant increase in media GAG and decreased levels of GAG in cartilage explants at the termination of the experiment. No significant differences were noted in outcomes measured in the cartilage explants with respect to the main effects of treatment (frozen versus freeze-dried serum), autologous versus allogeneic preparations or based on serum concentration.

Conclusions

The study did not observe any substantial differences in the response of cartilage to allogeneic freeze-dried CS when compared to other independent parameters (autologous and frozen preparations). Further investigation using in vivo systems appears warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03227-2.

A detailed macroscopic scoring system for experimental post-traumatic Osteoarthritis in the equine middle carpal joint

OBJECTIVE

Osteoarthritis (OA) is a significant health issue in humans as well as horses. Experimental models of equine carpal OA have been used to investigate OA pathogenesis and potential therapeutic candidates. A 5-scale scoring system (OARSI) for macroscopic pathological cartilage changes already exists, but there is a need for a scoring system with better differentiation of severity. The aim of this study was therefore to develop and validate such a scoring system.

RESULTS

New scoring system were developed for cartilage erosions (Copenhagen Equine Total Cartilage Score, CEqTCS) along with synovial membrane pathology and osteochondral fragment healing (Copenhagen Equine Carpal Osteoarthritis Score, CEqCOAS). For the CEqTCS there was excellent intraclass agreement (ICC = 0.993; CI 0.985-0.996; p = 1.08e-31) and consistency (ICC = 0.992; CI 0.985-0.996; p = 4.61e-31), as well as excellent interclass agreement (ICC = 0.974; CI 0.948-0.987, p = 2e-22) and consistency (ICC = 0.973; CI 0.946-0.987; p = 2.77e-22), while the OARSI system had moderate (κ = 0.47) and weak (κ = 0.28) inter- and intra-class agreement, respectively. The OARSI score and the CEqTCS correlated excellently, but every OARSI grade encompassed a wide range of CEqTCS grades. The new score for assessment of equine OA provides means to a better differentiation of OA changes than the existing OARSI system.

Surface topography as a tool to detect early changes in a posttraumatic equine model of osteoarthritis

The equine model of posttraumatic osteoarthritis (OA) mimics certain aspects of the naturally occurring disease, both in horses and humans. The objective of this study was to assess articular cartilage degeneration in a posttraumatic OA model using the established macroscopic and microscopic scoring systems and compare them with a novel surface topography analysis. OA was induced in the carpal joint of 15 (n = 15) mixed breed horses. Surface changes on the articular cartilage were characterized using osteochondral blocks from the third carpal bone (C3) and radial carpal bone using surface topography, standard histological grading, and gross evaluation of the joints. Significant differences were observed between OA and non-OA joints for gross evaluation scores. Microscopic scores of hematoxylin and eosin and Safranin O and Fast Green-stained sections demonstrated no differences between OA and non-OA joints. However, articular cartilage from the induced OA joint had significantly greater surface topography measurements compared with the sham treatment group, consistent with the changes seen on gross evaluation of joints. No significant correlations were noted between surface roughness measurements, histological assessment, and gross evaluation scores. The results suggest that surface topography analysis may provide a reliable objective approach to assess early changes in the cartilage surface in OA.

Examining the Effects of the Oral Supplement Biota orientalis in the Osteochondral Fragment-Exercise Model of Osteoarthritis in the Horse

Osteoarthritis (OA) is a common problem in horses. Several oral supplements have been proposed as treatments for horses with OA. The object of this study was to evaluate the use of the oil extract from the seeds of Biota orientalis (BO) for the treatment of experimentally induced OA in horses. OA was induced in 16, 2–5 year old horses in one middle carpal joint on Day 0; the other limb underwent a sham operation. Once daily oral treatment with BO or placebo was initiated on Day 0 and continued to Day 70. All horses were exercised 5 days a week starting on Day 14 through Day 70. The horses were evaluated every other week for lameness and serum GAG concentration as well as weekly synovial fluid assessment. Magnetic resonance imaging was performed on Day 7 and 70. Radiographic changes were assessed on Day 0, 14, and 70. On Day 70 tissue from the middle carpal joint was assessed macroscopically and histologically. All outcome parameters were compared between treatment groups to identify effects of treatment. Compared to placebo a significant decrease was found in synovial fluid prostaglandin E2 concentration and white blood cell counts in horses treated with BO. There was a significant reduction in radiographic scores for subchondral lysis of the radial carpal bone, osteophyte formation, subchondral sclerosis of the radial carpal bone, and total radiographic score for the horses treated with BO. There was no significant difference between treatment groups in clinical lameness findings, MRI findings, macroscopic grading or histologic grading. This study suggests a significant anti-inflammatory effect from oral BO that should be further investigated in clinical OA.

A safety evaluation of allogeneic freeze-dried platelet-rich plasma or conditioned serum compared to autologous frozen products equivalents in equine healthy joints

Background

Hemoderivatives such as autologous conditioned serum (ACS) and platelet-rich plasma (PRP) have been used as potential disease-modifying therapies in musculoskeletal disorders such as osteoarthritis (OA). These therapies are based on the delivery of multiple growth factors and anti-inflammatory cytokines that are known to participate in inflammatory processes. The variability of cytokine content due to the autologous nature of the product, the non-availability for immediate use and need for storage at low temperatures are limitations for its use in the field. An allogeneic freeze-dried conditioned serum (CS) and PRP would provide field clinicians with a more practical approach to use such products in daily practice. Based on in vitro preliminary data, this experimental study aimed to test the in vivo safety of allogeneic freeze-dried CS and PRP in healthy joints, using the horse as a model.

Results

Eight horses were randomly assigned and treated with PRP or CS. Horses had three joints injected with ALLO-FD PRP or CS, and three contralateral joints injected with the AUTO version of the same product, by a blinded clinician. Horses were evaluated clinically, and had synovial fluid collected at different time points and evaluated for cell content, PGE₂ and protein. Both CS and PRP products triggered a self-limiting and mild inflammatory response in equine healthy joints. This was indicated by the transient increase in nucleated cell count, PGE₂ and total protein in synovial fluid. This mild inflammatory response did not result in significant lameness and was not different among the groups.

Conclusions

The allogeneic freeze-dried PRP and CS showed to be overall safe and not dissimilar compared to their autologous frozen version in equine healthy joints. Further studies are necessary to evaluate the modulatory effects of these therapies in a clinical setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03225-4.

Current use of biologic therapies for musculoskeletal disease: A survey of board-certified equine specialists

Objective

To evaluate the use of mesenchymal stem cells (MSCs), autologous conditioned serum (ACS), platelet‐rich plasma (PRP), and autologous protein solution (APS) for the treatment of equine musculoskeletal disease by diplomates of the American College of Veterinary Surgery (ACVS), and American College of Veterinary Sports Medicine and Rehabilitation (ACVSMR).

Study design

Cross‐sectional study.

Sample population

Diplomates (n = 423).

Methods

An email link was sent to ACVS and ACVMR diplomates. A survey contained 59 questions regarding demographics, as well as indications, frequency, adverse effects, and limitations of use. Responses were analyzed using Fisher's exact test.

Results

One hundred and fifty four surveys were analyzed. Years in practice and type of practice were not associated with biologic therapy use. PRP was the most used therapy (120/137; 87.5%). PRP and MSCs were most often administered intralesionally while ACS and APS were most often administered intra‐articularly. ACS (50/104; 48.1%) treatment was repeated commonly within 2 weeks of initial injection. MSCs (39/90; 43.3%) and PRP (38/100; 38%) were commonly repeated 1‐2 months after initial injection and APS was typically repeated >4 months after initial injection (21/53; 39.6%). Local inflammation and expense were the most common adverse effect and limitation of use.

Conclusion

Diplomates most commonly utilized PRP and MSC intralesionally for soft‐tissue injuries, and ACS and ACP intra‐articularly for joint injury. Protocols for repeated administration varied widely. Local inflammation was a clinical concern with the use of biologics.

Clinical significance

Biologic therapies are used commonly by ACVS and ACVSMR diplomates for soft tissue and joint disease.

Arthroscopic findings and long-term outcomes in 76 sport horses with meniscal injuries (2008-2018)

OBJECTIVE

To report the findings and long-term outcome of 76 sport horses with meniscal injury.

STUDY DESIGN

Retrospective case series.

ANIMALS

Seventy-six horses with 93 meniscal injuries in 85 stifles.

METHODS

Medical records of sport horses diagnosed with meniscal injury during arthroscopy were reviewed. Owner follow up was obtained via telephone interview ≥1.5 years postoperatively. Preoperative and intraoperative findings, and postoperative treatments, were analyzed for potential association with return to athletic performance.

RESULTS

The medial meniscus was involved in 82.8% of cases, with grade 1 injuries diagnosed in 76.3% of menisci. Overall, 85.5% of horses returned to athletic performance, with 40% returning to their previous level. The grade of meniscal injury was associated with long-term outcome (P = .023). The presence of preoperative radiographic abnormalities (P = .259) or additional joint pathology (P = 1.00) was not associated with long-term outcomes. Fifty-nine stifles were treated with an orthobiologic: autologous conditioned serum, platelet-rich plasma, or marrow-derived mesenchymal stem cells. There was no association between the use of any orthobiologic and long-term outcome (P = .394).

CONCLUSION

This is the first report on long-term outcome of sport horses with meniscal injuries following arthroscopic surgery. Overall, the long-term prognosis was fair, with 40% of horses returning to their previous level of use. Severity of the meniscal injury was a prognostic indicator for return to work. The presence of radiographic abnormalities or additional joint pathology, or the use of orthobiologics, was not associated with long-term outcome.

CLINICAL SIGNIFICANCE

These findings can help in prognostication for sport horses with meniscal injuries.

Use of autologous conditioned serum dressings in hard-to-heal wounds: a randomised prospective clinical trial

OBJECTIVE

In this study, we aimed to assess both the efficacy and tolerability of autologous conditioned serum (ACS) as an innovative wound dressing in the local management of hard-to-heal wounds.

METHOD

In this single-blinded randomised controlled trial, patients with hard-to-heal wounds were randomly assigned to receive either ACS treatment or normal saline (NS) dressings. The treatment was applied once a week for three weeks with a final assessment at three weeks from the first ACS application.

RESULTS

A total of 30 patients took part in the study. Analysis of wound assessment data demonstrated statistically significant differences for wound surface area and Pressure Ulcer Scale for Healing scores (area score, exudate and tissue) from baseline to the end of the study in patients who received the ACS dressing, but not in patients who received the normal saline dressing. There were statistically significant differences in changes in: the wound surface area at week three (-6.4±2.69cm² versus +0.4±2.52cm²); area score at week three (-2.2±1.08 versus +0.2±0.86); exudate at week two (-1.2±0.70 versus +0.0±0.45) and at week 3 (-1.3±0.72 versus -0.1±0.63); tissue at week two (-1.1±0.35 versus +0.0±0.53) and at week three (-1.8±0.65 versus -0.1±0.63); and the PUSH total score at week one (-1.6±0.98 versus +0.4±1.22), week two (-3.2±0.86 versus +0.4±0.98) and week three (-5.3±1.17 versus -0.0±1.33) between the ACS and NS groups, respectively.

CONCLUSION

This trial revealed a significant decrease in wound surface area as well as a considerable improvement in wound healing in the ACS dressing group.

Platelet-Rich Plasma for Rheumatoid Arthritis: A Case Series

Rheumatoid Arthritis (RA) is a chronic disease characterized by severe inflammation that leads to degradation of articular cartilage and the formation of bony erosions. Currently, certain anesthesiologist-led pain management clinics have begun to take on a collaborative role in the treatment of patients with RA, as this progressive disease impairs work capacity due to chronic pain. We present three clinical cases in which platelet-rich plasma (PRP) was used for the treatment of RA in patients seeking a new therapy for pain control and improved range of motion, specifically in certain joints of the hand. The Patient Activity Scale II was employed as a standardized method to assess RA disease severity, recorded on the day of injection, at one month, at three months, and at six months. All of the included patients, ages 49, 60, and 63, had an established diagnosis of RA affecting the proximal interphalangeal and metacarpophalangeal joints of the hand. Over the course of six months, two out of three patients reported a 20% reduction in pain from the initial visit and a 30% improvement in overall well-being. The third patient noted a 50% decrease in pain from the initial visit and a 50% improvement in overall well-being. PRP treatment consistently resulted in functional improvement for each of the three patients treated, while also reducing long term pain and inflammation. Initial clinical and laboratory studies have shown that autologous plasma rich in platelets serves as a source of an abundance of growth factors once activated. The multitude of these growth factors injected into and around the diseased joints improves functionality in patients with RA indicating PRP may be a safe and beneficial therapy in patients with RA primarily affecting the joints of the hand.

Effects of Production Method and Repeated Freeze Thaw Cycles on Cytokine Concentrations and Microbial Contamination in Equine Autologous Conditioned Serum

Autologous conditioned serum (ACS) is a common intra-articular treatment for osteoarthritis in horses. The objective of this study was to investigate the influence of ACS preparation method on product contamination and concentrations of relevant cytokines and the influence of multiple freeze/thaw cycles. Blood was obtained from 10 healthy Thoroughbred horses and processed in parallel using a commercial and a non-commercial method to obtain ACS. Fluorescent microsphere immunoassay (FMIA) analysis was performed to quantify Interleukin 1 receptor antagonist (IL-1Ra), Interleukin-10 (IL-10), Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations in ACS obtained by both production methods. Effect of 3, 4 and 5 freeze/thaw cycles on concentrations of IL-1Ra, IL-10, IL-1β and TNF-α were assessed against baseline samples (2 cycles) in commercial ACS products. Standard aerobic and anaerobic culture methods were applied to both ACS products. Mixed effect one-way analyses of variance (ANOVA) were used to compare the two ACS production method for each cytokine. Repeated measures, mixed effect ANOVA were used to assess the effect of freeze/thaw on cytokine concentrations. Significance was set at P < 0.05. There was no difference in cytokine concentration between production methods (IL-1Ra P = 0.067, IL-1β P = 0.752, IL-10 P = 0.211 and TNF-α P = 0.25). Microbial growth was only observed in two samples obtained using the commercial production method. When compared to baseline, IL-1Ra concentration was decreased following the 5th freeze/thaw cycle (P < 0.001). These results suggest that the concentration of important cytokines are not influenced by ACS production method. When storing ACS samples for future use, freeze/thaw cycles associated with standard clinical practice are unlikely to influence cytokine concentrations. However, the lack of outcome measures associated with 1 or 2 freeze/thaw cycles represents a limitation of this study.

Effect of intravenous tiludronate disodium administration on the radiographic progression of osteoarthritis of the fetlock joint in Standardbred racehorses

OBJECTIVE

To compare the effects of tiludronate disodium and 3 other medical treatments on clinical and radiographic findings and biomarkers of disease progression in horses with osteoarthritis of the fetlock joint.

ANIMALS

100 Standardbred racehorses with spontaneous traumatic injury of the fetlock joint.

PROCEDURES

Horses were retrospectively grouped by whether they received tiludronate IV or triamcinolone acetonide and hyaluronan, polysulfated glycosaminoglycan, or interleukin-1 receptor antagonist protein intra-articularly. Data were collected on clinical, radiographic, and ultrasonographic findings and results for serum and synovial samples obtained before and 6 months after treatment. Lameness score, joint flexion test response, radiographic score, serum concentrations of tumor necrosis factor-α and carboxy-terminal telopeptides of collagen types I and II (CTX-I and II, respectively), and synovial fluid concentrations of interleukin-1β, prostaglandin E₂, and CTX-II were compared among treatments.

RESULTS

All treatments resulted in a significant improvement in lameness score and joint flexion test response at 6 months. In horses that received triamcinolone acetonide and hyaluronan, synovial fluid interleukin-1β, prostaglandin E₂, and CTX-II concentrations decreased after treatment, suggesting this treatment inhibited progression of hyaline cartilage degeneration and inflammatory processes. Horses that received tiludronate were the only group that had a decrease in radiographic score and serum CTX-I concentration after treatment, supporting the effect of tiludronate on bone metabolism. Tiludronate treatment was also followed by increases in serum and synovial fluid concentrations of CTX-II, a marker of cartilage damage.

CONCLUSIONS AND CLINICAL RELEVANCE

Tiludronate appeared to inhibit the radiographic progression of osteoarthritis in high-motion joints of racehorses at 6 months after treatment by inhibiting subchondral bone remodeling. Whether this effect was associated with a worsening of progressive cartilage damage remains to be ascertained.

Bone marrow mononuclear cells for joint therapy: The role of macrophages in inflammation resolution and tissue repair

Osteoarthritis (OA) is the most prevalent joint disease causing major disability and medical expenditures. Synovitis is a central feature of OA and is primarily driven by macrophages. Synovial macrophages not only drive inflammation but also its resolution, through a coordinated, simultaneous expression of pro- and anti-inflammatory mechanisms that are essential to counteract damage and recover homeostasis. Current OA therapies are largely based on anti-inflammatory principles and therefore block pro-inflammatory mechanisms such as prostaglandin E₂ and Nuclear factor-kappa B signaling pathways. However, such mechanisms are also innately required for mounting a pro-resolving response, and their blockage often results in chronic low-grade inflammation. Following minor injury, macrophages shield the damaged area and drive tissue repair. If the damage is more extensive, macrophages incite inflammation recruiting more macrophages from the bone marrow to maximize tissue repair and ultimately resolve inflammation. However, sustained damage and inflammation often overwhelms pro-resolving mechanisms of synovial macrophages leading to the chronic inflammation and related tissue degeneration observed in OA. Recently, experimental and clinical studies have shown that joint injection with autologous bone marrow mononuclear cells replenishes inflamed joints with macrophage and hematopoietic progenitors, enhancing mechanisms of inflammation resolution, providing remarkable and long-lasting effects. Besides creating an ideal environment for resolution with high concentrations of interleukin-10 and anabolic growth factors, macrophage progenitors also have a direct role in tissue repair. Macrophages constitute a large part of the early granulation tissue, and further transdifferentiate from myeloid into a mesenchymal phenotype. These cells, characterized as fibrocytes, are essential for repairing osteochondral defects. Ongoing “omics” studies focused on identifying key drivers of macrophage-mediated resolution of joint inflammation and those required for efficient osteochondral repair, have the potential to uncover ways for developing engineered macrophages or off-the-shelf pro-resolving therapies that can benefit patients suffering from many types of arthropaties, not only OA.

[Cell-based therapeutic strategies for osteoarthritis in equine patients - Basic knowledge for clinical practitioners]

Cell-based therapies for the treatment of osteoarthritis in equine patients experienced a real boom within the last few years. In every day medical practice, attending veterinary surgeons extract patient's blood or other autologous tissue samples and process the material for the purpose of administering the resulting product to the same patient under their own responsibility. Although being consistently classified as treatment option within the framework of regenerative medicine, the manufacturing processes, ingredients, and mechanisms of action remain highly diverse among cell-based therapies. Thus, sound knowledge about the latter ones forms the basis for therapeutic decision-making and best possible treatment regimes.

USE OF INTRACARPAL INTERLEUKIN RECEPTOR ANTAGONIST PROTEIN (IRAP) AND HYALURONIC ACID IN A MULTIMODAL THERAPEUTIC REGIME FOR OSTEOARTHRITIS IN AN ASIAN ELEPHANT (ELEPHAS MAXIMUS)

An approximately 41-yr-old female Asian elephant (Elephas maximus) experiencing forelimb stiffness and decreased range of motion was diagnosed with bilateral carpal osteoarthritis (OA). Standing sedation combined with local anesthesia was used to deliver ultrasound-guided carpal articular injections of an autologous conditioned serum product, interleukin receptor antagonist protein, combined with hyaluronic acid. Within 2 mo of completing therapy, improved range and speed of motion were evident. Reduced inflammation was suggested by decreased carpal articular prostaglandin E2 levels. Subjectively improved clinical signs lasted approximately 5-6 mo, at which point carpal articular injections were repeated. Joint inflammatory markers were useful in gauging response to treatment and may provide guidance in the diagnostic and therapeutic approach to elephant OA. On the basis of the positive response noted, interarticular autologous therapy combined with hyaluronic acid should be considered for carpal OA in elephants.

Evaluation of Villus Synovium From Unaffected Metacarpophalangeal Joints of Adult and Juvenile Horses

Horses are a widely accepted model for osteoarthritis (OA) research. Synovial tissue sampling is commonly used in studies to evaluate and grade the progress of OA or to assess treatment effects. Synovial explants play an important role in ex-vivo studies, increasingly replacing the use of living animals. To understand histomorphological changes in the process of joint-related diseases such as OA, detailed information about histomorphometric parameters of unaffected synovial villi is necessary. The objective of the present study was to evaluate the mean width of the intimal synovial lining and its cellularity as well as the vascularization of the subintimal layer in juvenile and adult horses not affected by a joint-related disease. One hundred synovial samples from both metacarpophalangeal joints from 25 horses (one day to 24 years old) were collected to evaluate the following parameters on digitalized hematoxylin-eosin stained samples: Width of intimal synovial lining measured by the distance from the inner joint surface to the subintimal layer; density of the cells making up the intimal synovial lining by counting cell nuclei; vascularization of the subintimal layer measured by the number and size of vessels in relation to the subintimal area. The median width of the intimal lining did not differ among juvenile (22.34 µm) and adult (23.34 µm) horses. The cellularity of the intimal lining was significantly lower in juvenile (one cell/143.8 µm²) than in adult (one cell /188.7µm²), (P < .001) horses as well as the density of blood vessels per mm² within the subintimal layer (juveniles 1/mm² vs. adults 0.05/mm²), (P < .001). This study provides morphometric data regarding synovial intimal width, intimal cellularity, and vascularization of equine synovial villi of unaffected horses. For future studies, age-related characteristics should be taken into consideration when synovial tissue samples are used for in-vivo and in-vitro studies.

Intra-articular injections of platelet-rich plasma vs. hyaluronic acid in patients with knee osteoarthritis: Preliminary follow-up results at 6-months

The aim of the present study was to compare the clinical and economic benefits of intra-articular injections of platelet-rich plasma (PRP) and hyaluronic acid (HA) in Chinese patients with knee osteoarthritis (OA). A total of 86 patients (42 treated with PRP and 44 with HA) were treated with three weekly intra-articular injections. The inclusion criteria included patients between 18 and 75 years of age, with chronic knee pain or swelling lasting >3 months and X-ray findings of degenerative joint alterations according to the Kellgren-Lawrence score grade I-III. Clinical examinations were performed before treatment, at 1- and 6-month post-injection intervals. International Knee Documentation Committee subjective, Western Ontario and McMaster Universities and visual analogue scale scores were determined at each examination. Adverse reactions, average cost, treatment time and patient satisfaction were also recorded. Compared with patients injected with HA, PRP was found to be associated with increased and more severe post-injection pain and swelling, where the duration of adverse reactions was greater in the PRP group (P=0.02). During the follow-up evaluations, both groups showed statistically significant improvements in all clinical scores from pre-injection to 1- and 6-month assessments (P<0.05). However, no significant inter-group (PRP vs. HA) differences were observed in the clinical scores between the two follow-up time points. There were also no significant differences in clinical score between the groups with regards to the Kellgren-Lawrence grade I, II or III. The average cost of PRP injections was 22.8X that of HA administration and the average treatment time was 5X that of HA, but there was no significant difference in patient satisfaction. These preliminary results indicate that although PRP injections can significantly improve clinical outcome in patients with knee OA, PRP is not any more effective compared with HA. Furthermore, PRP injections are associated with higher costs and treatment times. Therefore, additional clinical studies are required before PRP injections can be considered as a first-line treatment option for knee OA.

The Use of Autologous Protein Solution (Pro-Stride®) and Leukocyte-Rich Platelet-Rich Plasma (Restigen®) in Canine Medicine

The use of autologous orthobiologics is an emerging area of interest in veterinary medicine. In this retrospective study, we reviewed the clinical results achieved using two orthobiologics devices to address orthopedic injuries and tissue repair. Leukocyte (White blood cell)-rich platelet-rich plasma (L-PRP) devices produce outputs containing high concentrations of growth factors from venous blood. The Autologous Protein Solution (APS) device produces an orthobiologic containing high concentrations of growth factors and anti-inflammatory cytokines. L-PRP has commonly been used to address soft tissue injuries. APS has been injected into the joint to address osteoarthritis. In the last five years, our practice has treated 35 dogs (38 treatments) with L-PRP and 98 dogs (108 treatments) with APS. Our group has used L-PRP and APS to address orthopedic conditions including osteoarthritis, bursitis, tendinitis, tendon/ligament rupture/repair procedures, post-surgical femoral head osteotomy/tibial-plateau-leveling osteotomy tissue repair, lumbosacral stenosis, patellar luxation, joint laxity, and osteochondral dissecans. The results achieved with L-PRP and APS have been favorable (observed pain improvement and minimal adverse reactions), but sometimes have not achieved complete pain relief or tissue repair. The most common application for L-PRP was patellar luxation and the most common application for APS was injection post-ACL surgery. Canine OA has been successfully managed in several patients with repeat injections of APS over the course of several years. Future studies on specific conditions are ongoing and including efforts to further characterize these products in canine medicine.

Evaluation of Treatment With Respiratory Gene Technology and Serum in a Group of Standard Bred Racehorses With Cytological Evidence of Mild Equine Asthma

Alternative treatment options to glucocorticoids for equine asthma is desirable due to withdrawal time. The objective was to evaluate if serum and Respiratory Gene Technology (RGT), a commercial kit to produce autologous conditioned serum, was effective in reducing bronchoalveolar lavage (BAL) neutrophils and mast cells in racehorses with cytological evidence of mild equine asthma . Thirty-six Standardbred trotters in active training were enrolled in this randomized clinical trial; a healthy control group (n=11), a RGT group (n=12) and a serum group (n=13). Endoscopy including tracheal wash (TW) and BAL was performed before (T0), after a 6-week treatment period including 12 intramuscular injections of RGT or serum (T6) and as a follow-up 10 weeks after treatment (T16). A significant decrease in BAL neutrophils for the RGT group was found between T0 and T6 (P = .002, d=-1.51, CI: -2.43;-0.59) and for the serum group between T0-T6 (P = .002, d=-1.36, CI: -2.26;-0.46). Further, a significant decrease in BAL mast cells between T0-T6 for the both the RGT group (P = .019, d=-1.23, CI: -1.22;-0.34) and the serum group (P= .004, d=-0.81, CI: -1.65;0.04), and further between T0-T16 (RGT P= .011, d=-1.55, CI: -2.62;-0.48; serum P= .044, d=-0.65, CI: -1.68;-0.37). No significant difference in TW cytology was found for any of the time-points. Pro- and anti-inflammatory cytokines were regulated according to treatment. The control group showed no cytological differences between any time-point. Study results showed that intramuscular treatment with both RGT and serum was effective associated with reduction of BAL neutrophils and mast cells in horses with cytological evidence of mild equine asthma. Further large-scale studies are necessary.

Evaluation of Allogeneic Bone-Marrow-Derived and Umbilical Cord Blood-Derived Mesenchymal Stem Cells to Prevent the Development of Osteoarthritis in An Equine Model

Osteoarthritis (OA) is a significant cause of pain in both humans and horses with a high socio-economic impact. The horse is recognized as a pertinent model for human OA. In both species, regenerative therapy with allogeneic mesenchymal stem cells (MSCs) appears to be a promising treatment but, to date, no in vivo studies have attempted to compare the effects of different cell sources on the same individuals. The objective of this study is to evaluate the ability of a single blinded intra-articular injection of allogeneic bone-marrow (BM) derived MSCs and umbilical cord blood (UCB) derived MSC to limit the development of OA-associated pathological changes compared to placebo in a post-traumatic OA model applied to all four fetlock joints of eight horses. The effect of the tissue source (BM vs. UCB) is also assessed on the same individuals. Observations were carried out using clinical, radiographic, ultrasonographic, and magnetic resonance imaging methods as well as biochemical analysis of synovial fluid and postmortem microscopic and macroscopic evaluations of the joints until Week 12. A significant reduction in the progression of OA-associated changes measured with imaging techniques, especially radiography, was observed after injection of bone-marrow derived mesenchymal stem cells (BM-MSCs) compared to contralateral placebo injections. These results indicate that allogeneic BM-MSCs are a promising treatment for OA in horses and reinforce the importance of continuing research to validate these results and find innovative strategies that will optimize the therapeutic potential of these cells. However, they should be considered with caution given the low number of units per group.

Shoulder injections with autologous conditioned serum reduce pain and disability in glenohumeral osteoarthritis: longitudinal observational study

BACKGROUND

Currently, non-surgical treatments for glenohumeral osteoarthritis (GH-OA) mainly aim to reduce pain. Autologous conditioned serum (ACS), Orthokine, an interleukin-1 inhibitor from the patient's own blood has an anti-inflammatory effect. The objective was to determine whether intra-articular injections of this ACS improved symptoms in patients with GH-OA and delayed the need for a shoulder replacement.

METHODS

A total of 36 consecutive patients, 40 shoulders, with OA received up to 6-weekly intra-articular injections of ACS were included. Imaging of GH-OA, range of motion, visual analogue scale (VAS) pain, Shoulder Pain And Disability Index (SPADI), American Shoulder and Elbow Surgeons and Constant scores were assessed pre-injection and post treatment at 3 months. At a minimum of 2 years, VAS and SPADI scores and whether anyone had progressed to a shoulder replacement were recorded.

RESULTS

Outcomes 3 months post-ACS injections demonstrated on average statistically significant improvement (P < 0.05) of all measurements: SPADI (54.3 ± 21.5 vs 43.7 ± 23.7), Constant score (50.5 ± 14.1 vs 57.1 ± 17.4), VAS pain (4.8 ± 2.2 vs 3.7 ± 2.4) and range of motion. Of these, 16 shoulders progressed to a shoulder replacement, nine cases quickly (0.6 ± 0.2 years) and seven cases were delayed by 3.1 ± 1.7 years. The other 18 cases had significant improvement in pain, SPADI (58.0 ± 19.6 to 31.8 ± 21.4; P < 0.01) scores and no progression to a shoulder replacement at 3.6 ± 1.0 years follow-up. There was no correlation of glenoid Walch score or joint space with clinical outcome parameters.

CONCLUSION

ACS injections in the shoulder joint for OA can reduce pain and disability, and postpone the need for a shoulder replacement.

A Comparative Review of Autologous Conditioned Serum and Autologous Protein Solution for Treatment of Osteoarthritis in Horses

Many alternative treatments aimed at modulating osteoarthritis (OA) progression have been developed in the past decades, including the use of cytokine inhibitors. IL-1β is considered one of the most impactful cytokines in OA disease and therefore, its blockage offers a promising approach for the modulation of OA. Interleukin-1 receptor antagonist (IL-1Ra) is a naturally occurring anti-inflammatory protein belonging to the IL-1 family that competes with IL-1β for occupancy of its receptors, without triggering the same downstream inflammatory response. Because of its natural anti-inflammatory properties, different methods have been proposed to use IL-1Ra therapeutically in OA. Autologous conditioned serum (ACS) and autologous protein solution (APS) are blood-derived products produced with the use of specialized commercial kits. These processes result in hemoderivatives with high concentrations of IL-1Ra and other cytokines and growth factors with potential modulatory effects on OA progression. Several studies have demonstrated potential anti-inflammatory effect of these therapies with promising clinical results. However, as with any hemoderivatives, clinical outcomes may vary. For optimal therapeutic use, further research is warranted for a more comprehensive understanding of the product's composition and interaction of its components in joint inflammation. Additionally, differences between ACS and APS treatments may not be clear for many clients and clinicians. Thus, the objective of this narrative review is to guide the reader in important aspects of ACS and APS therapies, in vitro and in vivo applications and to compare the use of both treatments in OA.

Equine Cervical Pain and Dysfunction: Pathology, Diagnosis and Treatment

Simple Summary

Neck pain and dysfunction in the horse is becoming an increasingly important topic among riders, trainers and veterinarians. Some horses may present for a subtle performance decline, while others may show dramatic, dangerous behavior. It is important to recognize how to carefully evaluate the horse in an effort to understand the different types of pain that may be contributing to the different behaviors. The musculoskeletal and nervous systems may both play a role in the development of clinical signs. Recognizing that there are many diagnostic options as well as several treatments choices is important. This synopsis covers the disease processes that may contribute to the development of neck pain and dysfunction in the horse, as well as several possible diagnostic and treatment options.

Abstract

Interest in the cervical spine as a cause of pain or dysfunction is increasingly becoming the focus of many equine practitioners. Many affected horses are presented for poor performance, while others will present with dramatic, sometimes dangerous behavior. Understanding and distinguishing the different types of neck pain is a starting point to comprehending how the clinical presentations can vary so greatly. There are many steps needed to systematically evaluate the various tissues of the cervical spine to determine which components are contributing to cervical pain and dysfunction. Osseous structures, soft tissues and the central and the peripheral nervous system may all play a role in these various clinical presentations. After completing the clinical evaluation, several imaging modalities may be implemented to help determine the underlying pathologic processes. There are multiple treatment options available and each must be carefully chosen for an individual horse. Provided is a synopsis of the current knowledge as to different disease processes that can result in cervical pain and dysfunction, diagnostic approaches and treatment strategies. Improving the knowledge in these areas will ideally help to return horses to a state of well-being that can be maintained over time and through the rigors of their job or athletic endeavors.

Regenerative Medicine for Equine Musculoskeletal Diseases

Simple Summary

Lameness due to musculoskeletal disease is the most common diagnosis in equine veterinary practice. Many of these orthopaedic disorders are chronic problems, for which no clinically satisfactory treatment exists. Thus, high hopes are pinned on regenerative medicine, which aims to replace or regenerate cells, tissues, or organs to restore or establish normal function. Some regenerative medicine therapies have already made their way into equine clinical practice mainly to treat tendon injures, tendinopathies, cartilage injuries and degenerative joint disorders with promising but diverse results. This review summarises the current knowledge of commonly used regenerative medicine treatments and critically discusses their use.

Abstract

Musculoskeletal injuries and chronic degenerative diseases commonly affect both athletic and sedentary horses and can entail the end of their athletic careers. The ensuing repair processes frequently do not yield fully functional regeneration of the injured tissues but biomechanically inferior scar or replacement tissue, causing high reinjury rates, degenerative disease progression and chronic morbidity. Regenerative medicine is an emerging, rapidly evolving branch of translational medicine that aims to replace or regenerate cells, tissues, or organs to restore or establish normal function. It includes tissue engineering but also cell-based and cell-free stimulation of endogenous self-repair mechanisms. Some regenerative medicine therapies have made their way into equine clinical practice mainly to treat tendon injures, tendinopathies, cartilage injuries and degenerative joint disorders with promising results. However, the qualitative and quantitative spatiotemporal requirements for specific bioactive factors to trigger tissue regeneration in the injury response are still unknown, and consequently, therapeutic approaches and treatment results are diverse. To exploit the full potential of this burgeoning field of medicine, further research will be required and is ongoing. This review summarises the current knowledge of commonly used regenerative medicine treatments in equine patients and critically discusses their use.

Osteochondral Injury, Management and Tissue Engineering Approaches

Osteochondral lesions (OL) are a common clinical problem for orthopedic surgeons worldwide and are associated with multiple clinical scenarios ranging from trauma to osteonecrosis. OL vary from chondral lesions in that they involve the subchondral bone and chondral surface, making their management more complex than an isolated chondral injury. Subchondral bone involvement allows for a natural healing response from the body as marrow elements are able to come into contact with the defect site. However, this repair is inadequate resulting in fibrous scar tissue. The second differentiating feature of OL is that damage to the subchondral bone has deleterious effects on the mechanical strength and nutritive capabilities to the chondral joint surface. The clinical solution must, therefore, address both the articular cartilage as well as the subchondral bone beneath it to restore and preserve joint health. Both cartilage and subchondral bone have distinctive functional requirements and therefore their physical and biological characteristics are very much dissimilar, yet they must work together as one unit for ideal joint functioning. In the past, the obvious solution was autologous graft transfer, where an osteochondral bone plug was harvested from a non-weight bearing portion of the joint and implanted into the defect site. Allografts have been utilized similarly to eliminate the donor site morbidity associated with autologous techniques and overall results have been good but both techniques have their drawbacks and limitations. Tissue engineering has thus been an attractive option to create multiphasic scaffolds and implants. Biphasic and triphasic implants have been under explored and have both a chondral and subchondral component with an interface between the two to deliver an implant which is biocompatible and emulates the osteochondral unit as a whole. It has been a challenge to develop such implants and many manufacturing techniques have been utilized to bring together two unalike materials and combine them with cellular therapies. We summarize the functions of the osteochondral unit and describe the currently available management techniques under study.

A Survey of Clinical Usage of Non-steroidal Intra-Articular Therapeutics by Equine Practitioners

There are several non-steroidal intra-articular therapeutics (NSIATs) available for use by equine practitioners for the treatment of performance-limiting joint-related pathology. Information is limited on perceived clinical efficacy, recommended treatment protocols, and associated complications. Our objective with this cross-sectional survey was to investigate the current clinical usage of NSIATs by equine practitioners. An electronic cross-sectional convenience survey inquiring about the use of steroidal and NSIATS (platelet-rich plasma, autologous conditioned serum, autologous protein solution, cellular therapies, and polyacrylamide hydrogel) was distributed internationally to equine practitioners. A total of 353 surveys were completed. NSIATs were used by 87.5% of the participants. Corticosteroids and hyaluronic acid remain the intra-articular therapeutic of choice among practitioners, followed by autologous conditioned serum, platelet-rich plasma and autologous conditioned protein. Polyacrylamide hydrogel was the least used. Practitioners were more likely to use NSIATs if their caseload was > 50% equine (P < 0.001), they treated more than 10 horses intra-articularly per month (P < 0.001), and horses treated were considered English sport horses (P = 0.02). Years in practice and practice location did not influence the use of NSIATs. One of the most common reasons why NSIATs were chosen was to treat acute articular pathologies. As survey limitations, answers to questions regarding clinical response and complication rates were based on subjective estimation and practitioners recall, not clinical records. In conclusion, corticosteroids remain the most widely used intra-articular therapeutic. Among the NSIATs, blood-based products are more commonly used by practitioners, followed by cellular and synthetic products. Equine practitioners frequently use NSIATs, choosing to treat acute joint pathology more than previously reported.

Effects of Autologous Conditioned Serum, Autologous Protein Solution, and Triamcinolone on Inflammatory and Catabolic Gene Expression in Equine Cartilage and Synovial Explants Treated With IL-1β in Co-culture

Autologous conditioned serum (ACS) and autologous protein solution (APS) are newer therapeutic options for osteoarthritis (OA). Co-culture of cartilage and synovium stimulated with IL-1β produces a similar physiologic response to tissues from naturally-ocurring OA. The study objective was to investigate the effects of ACS, APS, and triamcinolone (TA) on inflammatory and catabolic gene expression of inflamed joint tissues in co-culture. Blood was collected and processed for ACS and APS from six horses. Cartilage and synovial explants were harvested from the stifle, placed in co-culture, and treated as: (1) unstimulated control (2) stimulated control (3) ACS at 25% v/v (4) ACS at 50% v/v (5) APS at 25% v/v (6) APS at 50% v/v, (7) TA (10⁻⁶ M). Treatment groups 2–7 were stimulated with IL-1β (10 ng/ml). Cultures were maintained for 96 hours, and then both media and explants were harvested for measurement of gene expression and protein. IL-1β stimulation significantly increased IL-1β (p = 0.029), IL-8 (p = 0.011) and MMP-3 (p = 0.043) expression in synovium and IL-1β (p = 0.003) and TNF-α (p = 0.001) expression in cartilage. Treatment with 50% ACS and APS v/v downregulated IL-1β expression in cartilage more than TA treatment (p = 0.001 and p = 0.0004) and APS downregulated MMP-1 expression in synovial membrane (p = 0.025). Treatment with ACS and APS caused a trend in upregulation of IL-10 expression in synovium and type II collagen and aggrecan expression in cartilage. PGE₂ media concentrations were significantly reduced following treatment with APS (13.7-fold decrease, p = 0.0001) and ACS (4.13-fold decrease, p = 0.024); while TA did not reduce PGE₂ significantly (2.3-fold decreased p = 0.406). As disease-modifying therapies, ACS and APS modified the cellular response from synovial membrane and articular cartilage. ACS and APS may offer an improved strategy to improve clinical signs of horses with naturally occurring OA, compared to TA treatment.

Repair of osteochondral defect using icariin-conditioned serum combined with chitosan in rabbit knees

BACKGROUND

Osteochondral defects caused by an acute traumatic injury or articular degeneration remains difficult to be manipulated. Repair of articular defects is still a great challenge for both tissue engineers and orthopedic surgeons. Therefore, combination of biomaterials with cartilage promotive drugs is well worth being developed to support the regeneration of both cartilage and subchondral bone.

METHODS

Rabbits undergoing osteochondral defect surgery were intrarticularly injected with icariin-conditioned serum (ICS), chitosan (CSSH) and combination of ICS with CSSH, respectively. Gait analysis was performed using VICON motion capture system. ICRS score and immunohistochemical (IHC) analysis including H&E, Safranin O, toluidine blue and collagen II staining was employed to evaluate macroscopic cartilage regeneration and determine the morphologic repair of cartilage.

RESULTS

Rabbits with the treatment of ICS or CSSH alone showed mild improvement in hopping time and range of joint angles while ICS-CSSH group exhibited longer jumping time and larger range of joint angles. In addition, femoral condyle in ICS-CSSH rabbits could be seen with more native cartilage and subchondral bone regeneration in both macroscopic observation and IHC analysis.

CONCLUSION

ICS combined with CSSH could promote the repair of osteochondral defect in rabbit knees. Combination of biomaterials with cartilage promotive drugs may ultimately have profound implications in the management of cartilage defect.