Mesenchymal stem cell injections improve symptoms of knee osteoarthritis

Efficacy of stromal vascular fraction for knee osteoarthritis: A prospective, single-centre, non-randomized study with 2 years follow-up

BACKGROUND

Current osteoarthritis (OA) treatments focus on symptom relief without addressing the underlying disease process. In regenerative medicine, current treatments have limitations. In regenerative medicine, more research is needed for intra-articular stromal vascular fraction (SVF) injections in OA, including dosage optimization, long-term efficacy, safety, comparisons with other treatments, and mechanism exploration.

AIM

To compare the efficacy of intra-articular SVF with corticosteroid (ICS) injections in patients with primary knee OA.

METHODS

The study included 50 patients with Kellgren-Lawrence grades II and III OA. Patients were randomly assigned (1:1) to receive either a single intra-articular SVF injection (group A) or a single intra-articular ICS (triamcinolone) (group B) injection. Patients were followed up at 1, 3, 6, 12, and 24 months. Visual analog score (VAS) and International Knee Documentation Committee (IKDC) scores were administered before the procedure and at all follow-ups. The safety of SVF in terms of adverse and severe adverse events was recorded. Statistical analysis was performed with SPSS Version 26.0, IBM Corp, Chicago, IL, United States.

RESULTS

Both groups had similar demographics and baseline clinical characteristics. Follow-up showed minor patient loss, resulting in 23 and 24 in groups A and B respectively. Group A experienced a notable reduction in pain, with VAS scores decreasing from 7.7 to 2.4 over 24 months, compared to a minor reduction from 7.8 to 6.2 in Group B. This difference in pain reduction in group A was statistically significant from the third month onwards. Additionally, Group A showed significant improvements in knee functionality, with IKDC scores rising from 33.4 to 83.10, whereas Group B saw a modest increase from 36.7 to 45.16. The improvement in Group A was statistically significant from 6 months and maintained through 24 months.

CONCLUSION

Our study demonstrated that intra-articular administration of SVF can lead to reduced pain and improved knee function in patients with primary knee OA. More adequately powered, multi-center, double-blinded, randomised clinical trials with longer follow-ups are needed to further establish safety and justify its clinical use.

Intra-Articular Application of Autologous, Fat-Derived Orthobiologics in the Treatment of Knee Osteoarthritis: A Systematic Review

The aim of this study was to review the current literature regarding the effects of intra-articularly applied, fat-derived orthobiologics (FDO) in the treatment of primary knee osteoarthritis over a mid-term follow-up period. A systematic literature search was conducted on the online databases of Scopus, PubMed, Ovid MEDLINE, and Cochrane Library. Studies investigating intra-articularly applied FDO with a minimum number of 10 knee osteoarthritis patients, a follow-up period of at least 2 years, and at least 1 reported functional parameter (pain level or Patient-Reported Outcome Measures) were included. Exclusion criteria encompassed focal chondral defects and techniques including additional arthroscopic bone marrow stimulation. In 28 of 29 studies, FDO showed a subjective improvement in symptoms (pain and Patient-Reported Outcome Measures) up to a maximum follow-up of 7.2 years. Radiographic cartilage regeneration up to 3 years postoperatively, as well as macroscopic cartilage regeneration investigated via second-look arthroscopy, may corroborate the favorable clinical findings in patients with knee osteoarthritis. The methodological heterogeneity in FDO treatments leads to variations in cell composition and represents a limitation in the current state of knowledge. However, this systematic review suggests that FDO injection leads to beneficial mid-term results including symptom reduction and preservation of the affected joint in knee osteoarthritis patients.

Intra-articular injection of bone marrow aspirate concentrate (mesenchymal stem cells) in KL grade III and IV knee osteoarthritis: 4 year results of 37 knees

Cell based therapies are increasingly used and results of bone marrow aspirate concentrate (BMAC) show encouraging short- to middle term results, superior to hyaluronic acid and platelet rich plasma (PRP). Most studies describe patients with mild to moderate arthritis and results of patients with KL III and IV osteoarthritis of the knee are limited to short term evaluations. Hence, the aim of this prospective study was to investigate the mid-term outcome of BMAC injections in patients with severe osteoarthritis of the knee. The BMAC was retrieved from the iliac crest as previously published with the "reorientation technique" from the iliac crest in supine position in analgosedation and injected into the patients' osteoarthritic knees. Patients were followed-up for 4 years. WOMAC, IKDC, SF 36 and walking distance were measured in a total of 37 participants. There was an improvement of IKDC and WOMAC from the first year onwards and a significant improvement beginning from year 2 up to the mid-term follow-up: IKDC increased significantly from 56 ± 12 (range 34-81) to 73 ± 13 (range 45-100), p < 0.001. WOMAC decreased significantly from 40 ± 23 (range 6-96) to 18 ± 18 (range 0-67), p < 0.001. 35 of 37 knees improved regarding IKDC and WOMAC score from the first to the last follow-up. Not a single protheses had to be implanted. Elaborate statistical analysis was done to exclude covariates and confounders (age, time, BMI,…). In summary, this is the first study on BMAC injections into 37 osteoarthritic knees with a 4-year follow up showing significant improvements in IKDC and WOMAC scores, and with a 95% success rate and significant improvement in walking distance.Clinical relevance Describes the 4-year outcome of BMAC injections for knees with severe osteoarthritis.

Stem Cells Expansion Vector via Bioadhesive Porous Microspheres for Accelerating Articular Cartilage Regeneration

Stem cell tissue engineering is a potential treatment for osteoarthritis. However, the number of stem cells that can be delivered, loss of stem cells during injection, and migration ability of stem cells limit applications of traditional stem cell tissue engineering. Herein, kartogenin (KGN)-loaded poly(lactic-co-glycolic acid) (PLGA) porous microspheres is first engineered via emulsification, and then anchored with chitosan through the amidation reaction to develop a new porous microsphere (PLGA-CS@KGN) as a stem cell expansion vector. Following 3D co-culture of the PLGA-CS@KGN carrier with mesenchymal stem cells (MSCs), the delivery system is injected into the capsule cavity in situ. In vivo and in vitro experiments show that PLGA-CS microspheres have a high cell-carrying capacity up to 1 × 104 mm-3 and provide effective protection of MSCs to promote their controlled release in the osteoarthritis microenvironment. Simultaneously, KGN loaded inside the microspheres effectively cooperated with PLGA-CS to induce MSCs to differentiate into chondrocytes. Overall, these findings indicate that PLGA-CS@KGN microspheres held high cell-loading ability, adapt to the migration and expansion of cells, and promote MSCs to express markers associated with cartilage repair. Thus, PLGA-CS@KGN can be used as a potential stem cell carrier for enhancing stem cell therapy in osteoarthritis treatment.

The 50 Most Cited Publications in Adipose-Derived "Stem Cell Therapies" with Application in Orthopaedic Surgery

Stem cell therapies have become widely popular in orthopaedic surgery, with a recent interest in adipose-derived therapeutics. Adipose-derived mesenchymal signaling cells (ADSCs) and micronized adipose tissue (MAT) are unique therapies derived from different processing methods. Characterizing the most influential studies in lipoaspirate research can help clarify controversies in definitions, identify core literature, and further collective knowledge for educational purposes. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched to identify the top 50 most cited publications (based on citation/year) on orthopaedic ADSCs or MAT research. Publication and study characteristics were extracted and reported using descriptive statistics. Level of evidence was assessed for applicable studies, and Spearman correlations were calculated to assess the relationship between citation data and level of evidence. The top 50 articles were published between the years 2003 and 2020, with 78% published in the year 2010 or later. The mean number of citations was 103.1 ± 81.1. The mean citation rate was 12.4 ± 6.0 citations per year. Of the 21 studies for which level of evidence was assessed, the majority were level III (10, 47.6%). The single study design most common among the top 50 cited articles was in vitro basic science studies (17 studies, 34%). Twenty-nine articles (58%) were classified as basic science or translational. Application to treat knee osteoarthritis was the most common focus of studies (14 studies, 28%), followed by in vitro analysis of growth factor and cell signaling markers (11 studies, 22%). No correlation was found between rank, citation rate, or year of publication and level of evidence. This study provides a current landscape on the most cited articles in lipoaspirates in orthopaedic surgery. With the expansion of ADSCs and MAT in the past two decades, this study provides the first historical landmark of the literature and a launching point for future research. Studies should explicitly state their processing methodology and whether their study investigates ADSCs or MAT to avoid misinformation.

StemOneTM/Stempeucel®: CDSCO Approved, Adult Human Bone Marrow-Derived, Cultured, Pooled, Allogenic Mesenchymal Stem Cells for Knee Osteoarthritis

The knee, the most likely joint to present osteoarthritis (OA), is accountable for approximately 80% of the global burden of the OA [...].

Knee Cartilage Lesion Management-Current Trends in Clinical Practice

Many patients, particularly those aged above 40, experience knee joint pain, which hampers both sports activities and daily living. Treating isolated chondral and osteochondral defects in the knee poses a significant clinical challenge, particularly in younger patients who are not typically recommended partial or total knee arthroplasty as alternatives. Several surgical approaches have been developed to address focal cartilage defects. The treatment strategies are characterized as palliation (e.g., chondroplasty and debridement), repair (e.g., drilling and microfracture), or restoration (e.g., autologous chondrocyte implantation, osteochondral autograft, and osteochondral allograft). This review offers an overview of the commonly employed clinical methods for treating articular cartilage defects, with a specific focus on the clinical trials conducted in the last decade. Our study reveals that, currently, no single technology fully meets the essential requirements for effective cartilage healing while remaining easily applicable during surgical procedures. Nevertheless, numerous methods are available, and the choice of treatment should consider factors such as the location and size of the cartilage lesion, patient preferences, and whether it is chondral or osteochondral in nature. Promising directions for the future include tissue engineering, stem cell therapies, and the development of pre-formed scaffolds from hyaline cartilage, offering hope for improved outcomes.

Clinical Outcome of Minimally Manipulated, Mechanically Isolated Autologous Adipose Tissue-Derived Stromal Vascular Fraction (Sahaj Therapy®) in Knee Osteoarthritis-Randomized Controlled Trial

Introduction

Regenerative therapy has shown promising results in the treatment of osteoarthritis (OA) knee with Kellgren-Lawrence (KL) Grades I-III. We compared the safety, efficacy, functional, and clinical outcomes of intra-articular implantation of autologous adipose tissue-derived stromal vascular fraction (SVF) isolated using direct ultrasonic cavitation (Sahaj therapy-Cell Innovation Patented Technology) and saline injection in knee osteoarthritis.

Materials and Methods

The present prospective observational study was conducted over 3 years. We enrolled 120 patients in our study, where four patients got excluded as they did not meet the inclusion criteria. The remaining 116 patients were randomized into two groups, one with autologous adipose tissue-derived SVF and the other group with saline injection. A comparison of mean KOOS and VAS scores at different follow-ups was done using Paired 't' test. A p value of < 0.05 was considered significant.

Results

The results show that the SVF group had significantly higher KOOS scores (78.49 ± 6.54 in the SVF group vs 59.19 ± 5.14 in the saline group), respectively (p < 0.001). Similarly, the SVF group had significantly lesser VAS scores (3.17 ± 0.94 in the SVF group vs 3.89 ± 1.04 in the saline group), respectively (p < 0.001).

Conclusions

Autologous adipose tissue-derived SVF is a better choice for treating knee osteoarthritis. For individuals with degenerative osteoarthritis, autologous SVF grafting in the same surgical procedure is an innovative and promising treatment modality. Even after 3 years of follow-up, the study participants with OA knee have shown a good clinical and functional outcome.

An Update on Clinical Utility of Musculoskeletal Ultrasonography in Knee Osteoarthritis

In knee osteoarthritis (KOA), timely and accurate assessment of the severity is essential to help orthopedic surgeons determine the most appropriate therapeutic strategies and evaluate disease outcomes and responses for corresponding treatments. In KOA, musculoskeletal ultrasonography (MSUS) could effectively help detect various abnormalities, including synovitis, osteophytes, and cartilage damage. Further, MSUS could be used to monitor the response to different therapies in KOA, to guide local diagnostic and therapeutic procedures. In the future, applications based on continuously evolving US tools could enhance the clinical utility of MSUS in KOA.

Amelioration of DSS-induced colitis in mice by TNF-α-stimulated mesenchymal stem cells derived from feline adipose tissue via COX-2/PGE2 activation

BACKGROUND

Mesenchymal stem cells (MSCs) have been investigated as therapeutic agents for inflammatory bowel disease (IBD). Stimulation of MSCs with pro-inflammatory cytokines is an approach to enhance their immunomodulatory effects. However, further investigation is required to support their application in immune-mediated disorders and companion animals.

OBJECTIVES

This study aimed to assess the therapeutic effect of tumor necrosis factor (TNF)-α-stimulated feline adipose tissue-derived MSCs (fAT-MSCs) in a dextran sulfate sodium (DSS)-induced colitis mouse model.

METHODS

Colitis mice was made by drinking water with 3% DSS and fAT-MSCs were injected intraperitoneally. Colons were collected on day 10. The severity of the disease was evaluated and compared. Raw 264.7 cells were cultured with the conditioned medium to determine the mechanism, using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS

TNF-α-stimulated fAT-MSCs more improved severity of DSS-induced colitis in disease activity, colon length, histologic score, and inflammatory cytokine. In sectionized colon tissues, the group comprising TNF-α-stimulated fAT-MSCs had higher proportion of CD11b+CD206+ macrophages than in the other groups. In vitro, TNF-α-stimulation increased cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) secretion from fAT-MSCs. The conditioned medium from TNF-α-stimulated fAT-MSCs enhanced the expression of interleukin-10 and arginase-1 in LPS-activated Raw 264.7 cells.

CONCLUSIONS

These results represent that TNF-α-stimulated fat-mscs ameliorate the inflamed colon more effectively. Furthermore, we demonstrated that the effectiveness was interlinked with the COX-2/PGE2 pathway.

A systematic review, umbrella review, and quality assessment on clinical translation of stem cell therapy for knee osteoarthritis: Are we there yet?

BACKGROUND

The success of stem cell therapy for knee osteoarthritis (KOA) in preclinical animal models has accelerated the pace of clinical translation. However, it remains uncertain whether the current scientific evidence supports the clinical application of stem cells in treating KOA. A comprehensive evaluation of the safety and efficacy of stem cell therapies and scientific evidence quality is necessary.

METHODS

Using "stem cells" and "knee osteoarthritis" as the search terms, several databases, including PubMed, Web of Science, Cochrane, Embase, and Clinicaltrials.gov, were searched on August 25, 2022, and updated on February 27, 2023. Clinical studies that reported adverse reactions (ARs) of stem cell therapy in KOA patients were included without limiting the type of studies. Quantitative systematic reviews of stem cell therapy for KOA that conducted meta-analysis were included. Two researchers conducted literature screening and data extraction independently, and the evidence quality was evaluated according to the Institute of Health Economics and AMSTAR 2 criteria.

RESULTS

Fifty clinical studies and 13 systematic reviews/meta-analyses (SRs/MAs) were included. Nineteen ARs were reported in 50 studies, including five knee-related ARs, seven common ARs, and seven other ARs. Some studies reported over 10% prevalence of knee pain (24.5%; 95% CI [14.7%, 35.7%]), knee effusion (12.5%; 95% CI [4.8%, 22.5%]), and knee swelling (11.9%; 95% CI [3.5%, 23.5%]). Additionally, two studies have reported cases of prostate cancer and breast tumors, respectively. However, these two studies suggest that stem cell therapy does not bring significant ARs to patients. SRs/MAs results revealed that stem cell therapy relieved pain in patients over time but did not improve knee function. However, current clinical studies have limited evidence regarding study objectives, test designs, and patient populations. Similarly, SRs/MAs have inadequate evidence regarding study design, risk of bias assessment, outcome description, comprehensive discussion, and potential conflicts of interest.

CONCLUSIONS

The inefficacy of stem cells, the risk of potential complications, and the limited quality of evidence from current studies precluded any recommendation for using stem cell products in patients with KOA. Clinical translation of stem cell therapies remains baseless and should be cautiously approached until more robust evidence is available. PROSPERO registration number: CRD42022355875.

Knee Osteoarthritis: Epidemiology, Pathogenesis, and Mesenchymal Stem Cells: What Else Is New? An Update

Osteoarthritis (OA) is a chronic disease and the most common orthopedic disorder. A vast majority of the social OA burden is related to hips and knees. The prevalence of knee OA varied across studies and such differences are reflected by the heterogeneity of data reported by studies conducted worldwide. A complete understanding of the pathogenetic mechanisms underlying this pathology is essential. The OA inflammatory process starts in the synovial membrane with the activation of the immune system, involving both humoral and cellular mediators. A crucial role in this process is played by the so-called “damage-associated molecular patterns” (DAMPs). Mesenchymal stem cells (MSCs) may be a promising option among all possible therapeutic options. However, many issues are still debated, such as the best cell source, their nature, and the right amount. Further studies are needed to clarify the remaining doubts. This review provides an overview of the most recent and relevant data on the molecular mechanism of cartilage damage in knee OA, including current therapeutic approaches in regenerative medicine.

Intra-articular delivery of antioxidative polymer-based nanospheres reduces intracellular reactive oxygen species in macrophages and alleviates cartilage damage in a rat model

Cartilage damage is frequent in various joint diseases, mainly manifested by the loss of type II collagen and the degradation of proteoglycans. Diclofenac sodium is a commonly used drug for the treatment of joint diseases, but simple administration is often affected by drug clearance and rapid metabolism. Intra-articular drug delivery is an effective method for local enrichment of high concentration of drugs. However, due to the short half-life of diclofenac sodium, prolonging the stability and duration of the drug can alleviate the disadvantages of direct intra-articular application. Nanospheres for delivering drugs to treat joint diseases could be a remedy for cartilage damage. In addition, excessive production of reactive oxygen species (ROS) by macrophages activated in damaged cartilage would aggravate cartilage damage. Therefore, this study intends to use poly lactic-co-glycolic acid nanospheres to load and deliver diclofenac sodium to inhibit chondrocyte death while regulating the generation of ROS, thereby promoting the treatment of cartilage damage.

Magnetically Actuated Microscaffold with Controllable Magnetization and Morphology for Regeneration of Osteochondral Tissue

Magnetic microscaffolds capable of targeted cell delivery have been developed for tissue regeneration. However, the microscaffolds developed so far with similar morphologies have limitations for applications to osteochondral disease, which requires simultaneous treatment of the cartilage and subchondral bone. This study proposes magnetically actuated microscaffolds tailored to the cartilage and subchondral bone for osteochondral tissue regeneration, named magnetically actuated microscaffolds for cartilage regeneration (MAM-CR) and for subchondral bone regeneration (MAM-SBR). The morphologies of the microscaffolds were controlled using a double emulsion and microfluidic flow. In addition, due to their different sizes, MAM-CR and MAM-SBR have different magnetizations because of the different amounts of magnetic nanoparticles attached to their surfaces. In terms of biocompatibility, both microscaffolds were shown to grow cells without toxicity as potential cell carriers. In magnetic actuation tests of the microscaffolds, the relatively larger MAM-SBR moved faster than the MAM-CR under the same magnetic field strength. In a feasibility test, the magnetic targeting of the microscaffolds in 3D knee cartilage phantoms showed that the MAM-SBR and MAM-CR were sequentially moved to the target sites. Thus, the proposed magnetically actuated microscaffolds provide noninvasive treatment for osteochondral tissue disease.

Outcome of Intra-articular Injection of Total Stromal Cells and Platelet-Rich Plasma in Primary Knee Osteoarthritis: A Randomized Clinical Trial

INTRODUCTION

 Mesenchymal stem cell (MSC) therapy appeared promising in knee osteoarthritis (OA). We examined if a single intra-articular (IA) autologous total stromal cells (TSC) and platelet-rich plasma (PRP) injection improved knee pain, physical function, and articular cartilage thickness in knee OA.

METHODS

 The study was performed in the physical medicine and rehabilitation department of Bangabandhu Shaikh Mujib Medical University, Dhaka, Bangladesh. Knee OA was diagnosed according to the American College of Rheumatology criteria and randomly assigned to treatment (received TSC and PRP) and control groups. Kallgreen-Lawrance (KL) scoring system was used to grade primary knee OA. The Visual Analogue Scale (VAS, 0-10 cm) for pain, WOMAC (Western Ontario and McMaster Universities Arthritis Index) for physical function, and medial femoral condylar cartilage (MFC) thickness (millimeters) under ultrasonogram (US) were documented and compared between groups before and after treatment. Statistical Package analyzed data for Social Scientists (SPSS 22.0; IBM Corp, Armonk, NY) was used for data analysis. Pre- and post-intervention outcomes were measured using the Wilcoxon-sign test, whereas Mann-Whitney U-test calculated the difference between groups; a p-value <0.05 was considered statistically significant.  Result: In the treatment group, 15 received IA-TSC and PRP preparation, and in the control group, 15 patients received no injection, but quadricep muscle-strengthening exercise. There was no significant difference between groups regarding VAS for pain, WOMAC physical function, and cartilage thickness before starting the treatment and two weeks after intervention. VAS for pain and WOMAC physical function scores improved profoundly in the treatment group after 12 and 24 weeks of intervention; the pain and physical function scores difference between groups was also significant. However, significant mean femoral cartilage thickness was not changed until the end of 24 weeks (U=175.00, p=0.009 two-tailed and U= 130.00, p=0.016 two-tailed, respectively, for right and left knee).

CONCLUSION

 Single TSC and PRP injection reduces knee pain and improves physical function and cartilage thickness in knee OA. While pain and physical function improvement happen earlier, cartilage thickness change takes more time.

Autologous Adipose-Derived Tissue Stromal Vascular Fraction (AD-tSVF) for Knee Osteoarthritis

Adipose tissue contains adult mesenchymal stem cells that may modulate the metabolism when applied to other tissues. Stromal vascular fraction (SVF) can be isolated from adipose tissue mechanically and/or enzymatically. SVF was recently used to decrease the pain and improve the function of knee osteoarthritis (OA) patients. Primary and/or secondary OA causes inflammation and degeneration in joints, and regenerative approaches that may modify the natural course of the disease are limited. SVF may modulate inflammation and initiate regeneration in joint tissues by initiating a paracrine effect. Chemokines released from SVF may slow down degeneration and stimulate regeneration in joints. In this review, we overviewed articular joint cartilage structures and functions, OA, and macro-, micro-, and nano-fat isolation techniques. Mechanic and enzymatic SVF processing techniques were summarized. Clinical outcomes of adipose tissue derived tissue SVF (AD-tSVF) were evaluated. Medical devices that can mechanically isolate AD-tSVF were listed, and publications referring to such devices were summarized. Recent review manuscripts were also systematically evaluated and included. Transferring adipose tissues and cells has its roots in plastic, reconstructive, and aesthetic surgery. Micro- and nano-fat is also transferred to other organs and tissues to stimulate regeneration as it contains regenerative cells. Minimal manipulation of the adipose tissue is recently preferred to isolate the regenerative cells without disrupting them from their natural environment. The number of patients in the follow-up studies are recently increasing. The duration of follow up is also increasing with favorable outcomes from the short- to mid-term. There are however variations for mean age and the severity of knee OA patients between studies. Positive outcomes are related to the higher number of cells in the AD-tSVF. Repetition of injections and concomitant treatments such as combining the AD-tSVF with platelet rich plasma or hyaluronan are not solidified. Good results were obtained when combined with arthroscopic debridement and micro- or nano-fracture techniques for small-sized cartilage defects. The optimum pressure applied to the tissues and cells during filtration and purification of the AD-tSVF is not specified yet. Quantitative monitoring of articular joint cartilage regeneration by ultrasound, MR, and synovial fluid analysis as well as with second-look arthroscopy could improve our current knowledge on AD-tSVF treatment in knee OA. AD-tSVF isolation techniques and technologies have the potential to improve knee OA treatment. The duration of centrifugation, filtration, washing, and purification should however be standardized. Using gravity-only for isolation and filtration could be a reasonable approach to avoid possible complications of other methodologies.

Is intra-articular injection of autologous micro-fragmented adipose tissue effective in hip osteoarthritis? A three year follow-up

Background

Recently, increased attention on regenerative medicine and biological injective treatments have been proposed to restore native cartilage. Micro-fragmented adipose tissue (MFAT) has been studied for its anti-inflammatory, paracrine, and immunomodulatory effects. The long-term effects of MFAT are still poorly understood: the aim of the present study is to demonstrate how hip articular injections with autologous MFAT can have an impact on clinical outcomes.

Methods

Seventy-one consecutive patients affected by early hip osteoarthritis underwent an ultrasound-guided hip injection of autologous MFAT between June 2017 and December 2018. Patients were divided into four groups according to the Oxford Hip Score. All patients received 4 mL of autologous micro-fragmented adipose tissue under an ultrasound guide. A clinical evaluation was done between 29 and 41 months after the initial treatment. During this follow-up period, we recorded any new treatment the patients had done, whether that be injection or arthroplasty surgery.

Results

The study included 55 patients. Out of 55 patients, 28 saw benefits and were in no need of further treatment. Moreover, the score between the beginning and control increased by 6.9 points. Ten patients underwent a new articular injection: the mean time between the two injections was 635.7 ± 180 days. Seventeen patients underwent total hip replacement: the mean period between the autologous MFAT injection and the surgery was 495 days.

Conclusion

This study found that intra-articular injections with autologous MFAT achieve beneficial clinical results in patients affected by early to moderate hip osteoarthritis, with an OHS between 48 and 30. Furthermore, these subjects are the ideal patients for whom this treatment obtains good clinical results.

Mesenchymal stem cells for subchondral bone marrow lesions: From bench to bedside

Subchondral bone marrow lesions (BMLs) are areas of disease within subchondral bone that appear as T1 hypointense and T2 hyperintense ill-defined areas of bone marrow on magnetic resonance imaging. The most common bone marrow lesions include subchondral lesions related to osteoarthritis, osteochondral defects, and avascular necrosis. Emerging therapies include autologous biologic therapeutics, in particular mesenchymal stem cells (MSCs), to maintain and improve cartilage health; MSCs have become a potential treatment option for BMLs given the unmet need for disease modification. Active areas in the preclinical research of bone marrow lesions include the paracrine function of MSCs in pathways of angiogenesis and inflammation, and the use of bioactive scaffolds to optimize the environment for implanted MSCs by facilitating chondrogenesis and higher bone volumes. A review of the clinical data demonstrates improvements in pain and functional outcomes when patients with knee osteoarthritis were treated with MSCs, suggesting that BM-MSCs can be a safe and effective treatment for patients with painful knee osteoarthritis with or without bone marrow lesions. Preliminary data examining MSCs in osteochondral defects suggest they can be beneficial as a subchondral injection alone, or as a surgical augmentation. In patients with hip avascular necrosis, those with earlier stage disease have improved outcomes when core decompression is augmented with MSCs, whereas patients in later stages post-collapse have equivalent outcomes with or without MSC treatment. While the evidence for the use of MSCs in conditions with associated bone marrow lesions seems promising, there remains a need for continued investigation into this treatment as a viable treatment option.

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Common BMLs include osteoarthritis, osteochondral defects, and avascular necrosis.

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Patients with knee osteoarthritis treated with MSCs show improved pain and function.

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MSCs used as subchondral injection or surgical augmentation in osteochondral defects

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Improved outcomes of early hip avascular necrosis after core decompression with MSCs

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Additional preclinical and clinical evidence of MSCs as treatment for BMLs is needed.

Bibliometric analysis of research trends in stem cell therapy for knee osteoarthritis over the period 2001–2021

Stem cell therapy is a promising treatment for knee osteoarthritis, but few bibliometric studies have been performed on the subject. Bibliometric analysis is helpful for identifying the most influential studies in a specific field and can evaluate the global research trends in stem cell therapy for knee osteoarthritis. The Web of Science Core Collection was searched for publications from 2001 to 2021. Publication performance was analyzed using several bibliometric parameters, including VOSviewer, to identify the research landscape of trends in topics, and CiteSpace was investigated to identify the keywords that have the strongest citation bursts. From 2001 to 2021, in total, 1,345 publications explored the research on stem cells in knee osteoarthritis. The United States contributed the largest number of publications and at the top list of international collaborations. Tokyo Medical and Dental University ranked first among institutions in the overall number of articles and citations. The journal of Osteoarthritis and Cartilage had the largest number of publications. Sekiya Ichiro was the most cited author, with 32 articles. The keywords with the most frequent occurrence were “osteoarthritis,” “mesenchymal stem cells,” and “cartilage,” in descending order of frequency. “fibroblast growth factor” and “extracellular vesicle” were the first and last searched theme terms, respectively. The number of publications on stem cells for knee osteoarthritis stays growing. Cartilage repair and paracrine function are current research hotspots for the stem cell therapy mechanism. Stem cell therapy has gradually advanced from basic research to the clinical application stage.

Mesenchymal stem cells augmentation for surgical procedures in patients with symptomatic chondral defects of the knee: a systematic review

Background

The efficacy and safety profile of mesenchymal stem cells (MSCs) augmentation in chondral procedures are controversial. This systematic review updated the current evidence on MSCs augmentation for chondral procedures in patients with symptomatic chondral defects of the knee.

Methods

This study followed the PRISMA guidelines. The literature search was updated in August 2022. Two independent authors accessed PubMed, Google scholar, Embase, and Scopus. No additional filters or time constrains were used for the search. A cross reference of the bibliographies was also performed. All the clinical studies investigating surgical procedures for chondral defects of the knee augmented with MSCs were accessed. Defects of both tibiofemoral and patellofemoral joints were included. The following patient reported outcomes measures (PROMs) were retrieved at baseline and last follow-up: Visual Analogic Scale (VAS), Tegner Activity Scale, Lysholm Knee Scoring System, International Knee Documentation Committee (IKDC). Return to daily activities and data on hypertrophy, failure, revision surgery were also collected. Failures were defined as the recurrence of symptoms attributable to the index procedure. Revisions were defined as any reoperation at the site of the index procedure.

Results

A total of 15 clinical studies (411 procedures) were included. Patients returned to their prior sport activity at 2.8 ± 0.4 months. All the PROMs improved at last follow-up: Tegner (P = 0.0002), Lysholm (P < 0.0001), the IKDC (P < 0.0001), VAS (P < 0.0001). At a mean of 30.1 ± 13.9 months, 3.1% (2 of 65 patients) reported graft hypertrophy, 3.2% (2 of 63) were considered failures. No surgical revision procedures were reported. Given the lack of available quantitative data for inclusion, a formal comparison of surgical procedures was not conducted.

Conclusion

MSCs augmentation in selected chondral procedures could be effective, with a low rate of complications. Further investigations are required to overcome the current limitations to allow the clinical translation of MSCs in regenerative medicine.

Stem cell-based therapies for temporomandibular joint osteoarthritis and regeneration of cartilage/osteochondral defects: a systematic review of preclinical experiments

OBJECTIVES

The aim of this systematic review was to assess the effects of stem cell-based therapies on the treatment of Temporomandibular Joint Osteoarthritis (TMJ-OA) and the regeneration of cartilage/osteochondral defects.

METHODS

Data on preclinical studies evaluating the effectiveness of stem cell-based therapies for treating Temporomandibular Disorders (TMDs) were extracted from PubMed, Web of Science, and Cochrane Library and the grey literature by three independent reviewers. A manual search was performed in the databases, the reference list of review studies, and relevant journals in the field. Compliance with the ARRIVE guidelines was evaluated for quality assessment. SYRCLE's risk of bias tool for animal experimental studies was assessed to define internal validity.

RESULTS

After applying the inclusion and exclusion criteria, 10 studies were included in the qualitative synthesis. Regardless of cell origin, stem cell-based therapeutic approaches induced protective, anti-inflammatory, and chondroregenerative potential in the treatment of TMJ-OA. Regeneration of the cartilage layer on the surface of the condyle was achieved when stem cells were directly flushed into the defect or when delivered within a carrier.

CONCLUSION

Stem cell-based therapies may be considered a promising approach for the treatment of TMJ-OA and for the regeneration of full-thickness cartilage and osteochondral defects in the TMJ. Human studies shall be performed to validate these results found in animals.

Clinical Safety and Effectiveness of Adipose-Derived Stromal Cell vs Stromal Vascular Fraction Injection for Treatment of Knee Osteoarthritis: 2-Year Results of Parallel Single-Arm Trials

BACKGROUND

There are currently no disease-modifying treatments available for knee osteoarthritis (OA), although cultured adipose-derived stromal cells (ASCs) have shown promise in experimental models. However, given the regulatory limits on the use of cultured cells in humans, previous trials have focused primarily on the stromal vascular fraction (SVF) intra-articular injection. Therefore, the therapeutic value of ASCs for knee OA remains unknown.

PURPOSE

To study ASC versus SVF intra-articular injection in patients with Kellgren-Lawrence (KL) knee OA grades 2 to 4 in parallel single-arm trials.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 80 patients were enrolled, with 42 (72 knees) receiving ASC intra-articular injection and 38 (69 knees) receiving SVF. Patient-reported outcome measures were assessed at 1, 3, 6, 12, and 24 months using the Knee injury and Osteoarthritis Outcome Score 5 (KOOS5) and pain visual analog scale (VAS). The percentages of patients achieving the minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) were also calculated. Per protocol, a subset of the ASC group received an ASC booster injection after 6 months. A repeated-measures analysis of variance compared results between treatment arms and by KL grade over time.

RESULTS

Patient-reported outcome measures improved substantially after both treatments (P < .05 at all time points), with the ASC group more likely to achieve the MCID (50% vs 24%; P = .01) and PASS (45% vs 24%; P = .04) for the pain VAS and the MCID (43% vs 16%; P = .02) for the KOOS5 at 12 months, although not at 24 months. Knees treated with ASC for KL grade 2/3 OA had significantly superior outcomes compared with those with KL grade 4 OA for the KOOS5 (P = .01) and pain VAS (P = .03), but no such difference was observed in knees treated with SVF. Three patients receiving ASCs (7%; all KL grade 3) sought additional nonoperative treatment by 24 months versus 9 patients receiving SVF (24%; all KL grade 3) (P = .06). ASC booster injections conferred no additional benefit. Notably, patients in the ASC cohort reported more injection-site pain and swelling after the booster injection than after the initial injection (P < .01).

CONCLUSION

This represents the first head-to-head comparison of ASCs and SVF for the treatment of knee OA in humans. ASC and SVF injections both substantially improved knee pain and function at all follow-up time points, although ASC injections demonstrated significantly better improvements with regard to the MCID and PASS for the pain VAS and the MCID for the KOOS5 at 12 months. There appears to be no benefit to a booster ASC injection after initial treatment. Given less donor-site morbidity and equivalent superior outcomes at 2 years, the use of ASCs over SVF in the treatment of knee OA may be warranted.

Clinical Efficacy of Bone Marrow Aspirate Concentrate Versus Stromal Vascular Fraction Injection in Patients With Knee Osteoarthritis: A Systematic Review and Meta-analysis

BACKGROUND

Knee injection using either bone marrow aspirate concentrate (BMAC) or stromal vascular fraction (SVF) from adipose tissue has been shown to result in symptomatic improvement in patients with knee osteoarthritis (OA). It is still unclear whether one of these therapies is superior over the other.

PURPOSE

To systematically report the clinical studies evaluating BMAC and SVF in the treatment of knee OA and to compare the clinical efficacy of these 2 injection therapies.

STUDY DESIGN

Meta-analysis; Level of evidence, 4.

METHODS

This meta-analysis was performed per the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Studies were included if they reported the clinical outcomes after a single BMAC or SVF injection in the knee joint of patients with OA. Studies evaluating preparations of culture-expanded stem cells were excluded. A random effects model was used; the clinical efficacy of BMAC or SVF injection was assessed using the standardized mean difference (SMD) and compared. Visual analog scale (VAS) scores for pain and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) knee index were the primary outcomes. The level of statistical significance was set at P < .05.

RESULTS

Ten studies and 472 patients with knee OA who received either BMAC (233 patients) or SVF (239 patients) were included. Patients who received an injection had improved VAS outcomes (mean ± SD): from 5.8 ± 1.3 to 2.6 ± 17 for BMAC and from 6.4 ± 1.4 to 3.4 ± 0.5 for SVF. They also experienced significantly reduced pain (SMD [VAS], 2.6 for BMAC and 3.4 for SVF) and improved function (SMD [WOMAC], 1.4 for BMAC and 1.2 for SVF). However, the SVF injection had a significantly greater effect on pain reduction than did the BMAC injection (P < .0001). Based on WOMAC, the clinical effect of BMAC versus SVF knee injection in patients with knee OA was equivalent (P = .626). Results were limited by the presence of publication bias as well as variability in the preparation methods utilized in the BMAC and SVF injection protocols. Complications were reported in 50% of the BMAC studies (knee stiffness, persistent knee swelling) and 67% of the SVF studies (knee swelling, knee pain, positive SVF cultures without symptoms of infection, and bleeding at the abdominal harvest site).

CONCLUSION

A single BMAC or SVF injection into the knee joint of patients with OA resulted in symptomatic improvement at short-term follow-up. However, SVF seemed to be more effective than did BMAC in the reduction of knee pain. There was significant variation in the BMAC and SVF injection preparation techniques used across the studies and a lack of stratification of outcomes based on the radiologic classification of OA. Therefore, these results should be taken with caution.

Methodological Flaws in Meta-Analyses of Clinical Studies on the Management of Knee Osteoarthritis with Stem Cells: A Systematic Review

(1) Background: Conclusions of meta-analyses of clinical studies may substantially influence opinions of prospective patients and stakeholders in healthcare. Nineteen meta-analyses of clinical studies on the management of primary knee osteoarthritis (pkOA) with stem cells, published between January 2020 and July 2021, came to inconsistent conclusions regarding the efficacy of this treatment modality. It is possible that a separate meta-analysis based on an independent, systematic assessment of clinical studies on the management of pkOA with stem cells may reach a different conclusion. (2) Methods: PubMed, Web of Science, and the Cochrane Library were systematically searched for clinical studies and meta-analyses of clinical studies on the management of pkOA with stem cells. All clinical studies and meta-analyses identified were evaluated in detail, as were all sub-analyses included in the meta-analyses. (3) Results: The inconsistent conclusions regarding the efficacy of treating pkOA with stem cells in the 19 assessed meta-analyses were most probably based on substantial differences in literature search strategies among different authors, misconceptions about meta-analyses themselves, and misconceptions about the comparability of different types of stem cells with regard to their safety and regenerative potential. An independent, systematic review of the literature yielded a total of 183 studies, of which 33 were randomized clinical trials, including a total of 6860 patients with pkOA. However, it was not possible to perform a scientifically sound meta-analysis. (4) Conclusions: Clinicians should interpret the results of the 19 assessed meta-analyses of clinical studies on the management of pkOA with stem cells with caution and should be cautious of the conclusions drawn therein. Clinicians and researchers should strive to participate in FDA and/or EMA reviewed and approved clinical trials to provide clinically and statistically valid efficacy.

Preclinical studies and clinical trials on mesenchymal stem cell therapy for knee osteoarthritis: A systematic review on models and cell doses

AIM

To provide a systematic analysis of the study design in knee osteoarthritis (OA) preclinical studies, focusing on the characteristics of animal models and cell doses, and to compare these to the characteristics of clinical trials using mesenchymal stem cells (MSCs) for the treatment of knee OA.

METHOD

A systematic and comprehensive search was conducted using the PubMed, Web of Science, Ovid, and Embase electronic databases for research papers published in 2009-2020 on testing MSC treatment in OA animal models. The PubMed database and ClinicalTrials.gov website were used to search for published studies reporting clinical trials of MSC therapy for knee OA.

RESULTS

In total, 9234 articles and two additional records were retrieved, of which 120 studies comprising preclinical and clinical studies were included for analysis. Among the preclinical studies, rats were the most commonly used species for modeling knee OA, and anterior cruciate ligament transection was the most commonly used method for inducing OA. There was a correlation between the cell dose and body weight of the animal. In clinical trials, there was large variation in the dose of MSCs used to treat knee OA, ranging from 1 × 10⁶ to 200 × 10⁶ cells with an average of 37.91 × 10⁶ cells.

CONCLUSION

Mesenchymal stem cells have shown great potential in improving pain relief and tissue protection in both preclinical and clinical studies of knee OA. Further high-quality preclinical and clinical studies are needed to explore the dose effectiveness relationship of MSC therapy and to translate the findings from preclinical studies to humans.

Potential of Using Infrapatellar–Fat–Pad–Derived Mesenchymal Stem Cells for Therapy in Degenerative Arthritis: Chondrogenesis, Exosomes, and Transcription Regulation

Infrapatellar fat pad–derived mesenchymal stem cells (IPFP-MSCs) are a type of adipose-derived stem cell (ADSC). They potentially contribute to cartilage regeneration and modulation of the immune microenvironment in patients with osteoarthritis (OA). The ability of IPFP-MSCs to increase chondrogenic capacity has been reported to be greater, less age dependent, and less affected by inflammatory changes than that of other MSCs. Transcription-regulatory factors strictly regulate the cartilage differentiation of MSCs. However, few studies have explored the effect of transcriptional factors on IPFP-MSC-based neocartilage formation, cartilage engineering, and tissue functionality during and after chondrogenesis. Instead of intact MSCs, MSC-derived extracellular vesicles could be used for the treatment of OA. Furthermore, exosomes are increasingly being considered the principal therapeutic agent in MSC secretions that is responsible for the regenerative and immunomodulatory functions of MSCs in cartilage repair. The present study provides an overview of advancements in enhancement strategies for IPFP-MSC chondrogenic differentiation, including the effects of transcriptional factors, the modulation of released exosomes, delivery mechanisms for MSCs, and ethical and regulatory points concerning the development of MSC products. This review will contribute to the understanding of the IPFP-MSC chondrogenic differentiation process and enable the improvement of IPFP-MSC-based cartilage tissue engineering.

What is the clinically significant ideal mesenchymal stromal cell count in the management of osteoarthritis of the knee? - Meta-analysis of randomized controlled trials

STUDY DESIGN

Meta-analysis.

OBJECTIVES

We aim to identify the clinically significant ideal Mesenchymal Stem Cell (MSC) count in the management of osteoarthritis of knee from Randomized Controlled Trials (RCTs) available in the literature.

MATERIALS AND METHODS

We conducted independent and duplicate electronic database searches including PubMed, Embase, Web of Science, and Cochrane Library till August 2021 for RCTs conducted in the management of knee osteoarthritis using MSC therapy specifying the quantity of MSCs delivered. We categorized the studies based on the MSC count utilized in them into four groups namely <1 × 10⁷ MSCs (Group I), 1-5x10⁷ MSCs (Group II), 5-10 × 10⁷ MSCs (Group III), and >10 × 10⁷ MSCs (Group IV). Visual Analog Score (VAS) for Pain, Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, Knee Osteoarthritis Outcome Score (KOOS), and adverse events were the outcomes analyzed. Analysis was performed in R-platform using OpenMeta [Analyst] software.

RESULTS

14 studies involving 564 patients were included for analysis. We noted incremental decrease in the VAS with increasing dosage of MSCs at 12 months [Group I,WMD = 2.641(p = 0.854); Group II, WMD = -4.853(p = 0.379); Group III, WMD = -12.154 (p = 0.316); Group IV, WMD = -15.935(p = 0.116)], and 24 months [Group I,WMD = -6(p = 0.001); Group II, WMD = -15(p = 0.001); Group IV, WMD = -20(p = 0.001)]. We also noted incremental improvement in the WOMAC, KOOS with increasing dosage of MSCs at 12 months [Group I, WMD = 7(p = 0.001); Group II, WMD = 28(p = 0.001); Group IV, WMD = 30(p = 0.001)] and [Group II, WMD = -2.562(p = 0.676); Group III, WMD = 7.670(p = 0.099); Group IV, WMD = 13.475(p = 0.261)] respectively. However, we noted significant reduction in the Lysholm score in Group IV, compared to the others at 12 months (WMD = -12.5, 95%CI[-25.883,0.883]) and 24 months (WMD = -6.6, 95%CI[-23.596,10.396]). We did not find any significant increase in the adverse events with incremental dosage of MSCs in any of the groups compared.

CONCLUSION

Compared to the four dosage groups of MSCs analyzed, Group III showed consistent significant improvement in pain and functional outcomes analyzed compared to the other groups. Hence, we recommend a cell volume of 5-10 × 10⁷ cells to be delivered to the target site to obtain superior benefits out of the procedure. However, we urge future trials of sufficient quality to validate our findings to arrive at a consensus on the ideal count of MSCs to be delivered in the cellular therapy for knee osteoarthritis.

The Effect of Autologous Adipose-Derived Stromal Vascular Fractions on Cartilage Regeneration Was Quantitatively Evaluated Based on the 3D-FS-SPGR Sequence: A Clinical Trial Study

Background

Numerous reports confirmed the safety and clinical efficacy of autologous adipose-derived stromal vascular fractions (SVF), which have recently been used to treat osteoarthritis (OA). However, there is still no consensus as to whether SVF can promote cartilage regeneration. Herein, the purpose of our study was to evaluate the effectiveness of SVF versus hyaluronic acid (HA) in cartilage regeneration by establishing a cartilage model based on the three-dimensional fat-suppressed spoiled gradient recalled echo (3D-FS-SPGR) sequence.

Methods

Patients with symptomatic OA were recruited in our research, who were randomized into two groups. Meanwhile, patients in Kellgren-Lawrence (K-L) grades 2 and 3 were distinguished in each group. In the test group, patients received SVF injections of the knee, while patients in the control group received the same dose of HA. Each patient underwent the 3D-FS-SPGR sequence to establish a cartilage model at baseline, 6 months, and 12 months, respectively. The cartilage was characterized into six regions, and relevant parameters of the cartilage model were counted. Clinical and radiographic scores were recorded in one-year follow-up.

Results

In all regions, the thickness and volume of cartilage defect and the volume of healthy cartilage were improved to some extent in the test group, especially the medial femoral condyle (MF) and medial tibial condyle (MT). In grades 2 and 3, the thickness and volume of cartilage defect decreased by 0.92 ± 0.18 mm and 1.03 ± 0.23 mm and 84.00 ± 32.30 mm³ and 130.30 ± 49.56 mm³ in MF and by 0.96 ± 0.22 mm and 0.99 ± 0.14 mm and 64.18 ± 21.40 mm³ and 95.11 ± 19.93 mm³ in MT, respectively. No such phenomenon was observed in the control group. Meanwhile, the SVF-treated knees showed significant improvement in clinical and radiographic scores at 12 months. Nevertheless, these scores of the control group became worse at 12-month follow-up visit.

Conclusion

Taken together, this study shows that intra-articular injection of SVF markedly improved the clinical symptoms without adverse events, thereby repairing the damaged articular cartilage through cartilage regeneration.

Evaluation of the Usefulness of Human Adipose-Derived Stem Cell Spheroids Formed Using SphereRing® and the Lethal Damage Sensitivity to Synovial Fluid In Vitro

Osteoarthritis (OA) is an irreversible degenerative condition causing bone deformation in the joints and articular cartilage degeneration with chronic pain and impaired movement. Adipose-derived stem cell (ADSC) or crushed adipose tissue injection into the joint cavity reportedly improve knee function and symptoms, including pain. Stem cell spheroids may be promising treatment options due to their anti-inflammatory and enhanced tissue regeneration/repair effects. Herein, to form human ADSC spheroids, we used first SphereRing® (Fukoku Co., Ltd., Ageo, Japan), a newly developed rotating donut-shaped tube and determined their characteristics by DNA microarray of mRNA analysis. The variable gene expression cluster was then identified and validated by RT-PCR. Gene expression fluctuations were observed, such as COL15A1 and ANGPTL2, related to vascular endothelial cells and angiogenesis, and TNC, involved in tissue formation. In addition, multiplex cytokine analysis in the medium revealed significant cytokines and growth factors production increase of IL-6, IL-10, etc. However, ADSC administration into the joint cavity involves their contact with the synovial fluid (SF). Therefore, we examined how SF collected from OA patient joint cavities affect 2D-culture ADSCs and ADSC spheroids and observed SF induced cell death. ADSC spheroids could become promising OA treatment options, although studying the administration methods and consider their interaction with SF is essential.

Bone marrow aspirate concentrate versus platelet-rich plasma for treating knee osteoarthritis: a one-year non-randomized retrospective comparative study

Background

Knee osteoarthritis (OA) is a debilitating condition affecting human body biomechanics and quality of life. Current standard care for knee OA leads to trivial improvement and entails multiple adverse effects or complications. Recently, investigational cell therapies injected intra-articularly, such as bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP), have shown safety and therapeutic potency providing patients with pain relief. In the current retrospective comparative study, we investigated the differences in pain and functional improvements in patients with symptomatic knee OA receiving intra-articular injections of BMAC vs PRP.

Methods

Pain and functionality scores were measured at baseline and at different time points post-injection over 12 months, using 3 self-administered, clinically validated questionnaires: the visual analogue scale (VAS) for assessing pain intensity, the knee injury and osteoarthritis outcome score (KOOS) for evaluating functionality and knee-related quality of life, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) for evaluating physical function. The repeated-measures general linear model with Sidak test for pairwise comparisons was used to investigate the influence of the treatment on the score evolution within groups (between baseline and each time point) and between groups (overall).

Results

The BMAC group (n = 26 knees) significantly improved in VAS, KOOS, and WOMAC scores between baseline and 12 months (57.4, 75.88, and 73.95% mean score improvement, respectively). In contrast, the PRP group (n = 13 knees) witnessed nonsignificant improvement in all scores. BMAC, in comparison to PRP, induced significant improvement in outcomes by 29.38% on the VAS scale, 53.89% on the KOOS scale, and 51.71% on the WOMAC scale (P < .002, P < .01, P < .011, respectively).

Conclusions

Intra-articular autologous BMAC injections are safe, effective in treating pain, and ameliorate functionality in patients with symptomatic knee OA to a greater extent than PRP injections.

Graphical abstract

Intra-articular autologous BMAC therapy is safe and provides more relief to patients with symptomatic knee osteoarthritis compared to PRP therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04910-5.

Adipose Tissue-Derived Mesenchymal Stem Cells as a Potential Restorative Treatment for Cartilage Defects: A PRISMA Review and Meta-Analysis

Cartilage defects are a predisposing factor for osteoarthritis. Conventional therapies are mostly palliative and there is an interest in developing newer therapies that target the disease’s progression. Mesenchymal stem cells (MSCs) have been suggested as a promising therapy to restore hyaline cartilage to cartilage defects, though the optimal cell source has remained under investigation. A PRISMA systematic review was conducted utilising five databases (MEDLINE, EMBASE, Cochrane Library, Scopus, Web of Science) which identified nineteen human studies that used adipose tissue-derived MSC (AMSC)-based therapies, including culture-expanded AMSCs and stromal vascular fraction, to treat cartilage defects. Clinical, imaging and histological outcomes, as well as other relevant details pertaining to cartilage regeneration, were extracted from each study. Pooled analysis revealed a significant improvement in WOMAC scores (mean difference: −25.52; 95%CI (−30.93, −20.10); p < 0.001), VAS scores (mean difference: −3.30; 95%CI (−3.72, −2.89); p < 0.001), KOOS scores and end point MOCART score (mean: 68.12; 95%CI (62.18, 74.05)), thus showing improvement. The studies in this review demonstrate the safety and efficacy of AMSC-based therapies for cartilage defects. Establishing standardised methods for MSC extraction and delivery, and performing studies with long follow-up should enable future high-quality research to provide the evidence needed to bring AMSC-based therapies into the market.

Infrapatellar fat pad-derived mesenchymal stromal cell product for treatment of knee osteoarthritis: a first-in-human study with evaluation of the potency marker

BACKGROUND AIMS

Infrapatellar fat pad-derived mesenchymal stromal cells (IFP-MSCs) have not yet been used in a human clinical trial. In this open-label phase 1 study, patients with knee osteoarthritis (OA) received a single intra-articular injection of autologous IFP-MSCs. Safety was assessed through physical examination of the knee joint, vital signs, laboratory tests and adverse events. Efficacy was evaluated with regard to pain and function using questionnaires, x-ray and magnetic resonance imaging (MRI). Indoleamine-2,3-dioxygenase (IDO) expression in IFP-MSCs primed with interferon gamma was used as an in vitro potency measurement in investigating the correlations of clinical outcomes.

METHODS

Twelve patients with symptomatic knee OA were recruited. IFP adipose tissue was harvested from each patient's knee through surgical excision for IFP-MSC manufacturing. Cryopreserved IFP-MSCs (5 × 10⁷ cells) were injected into the knee joint immediately after thawing.

RESULTS

No significant adverse events were observed. Patients who received IFP-MSCs exhibited clinically significant pain and functional improvement at 48-week follow-up. The MRI Osteoarthritis Knee Score average was also significantly reduced from 100.2 before injection to 85.0 at 48 weeks after injection. The IDO expression of the primed IFP-MSCs of the 12 patients was correlated with clinical outcomes after injection.

CONCLUSIONS

A single intra-articular injection of IFP-MSCs appears to be a safe therapy for treating knee OA and may improve disease symptoms. IDO measurement of primed IFP-MSCs has potential as a potency marker of MSC products for immunomodulatory therapy.

Platelets and Adipose Stroma Combined for the Treatment of the Arthritic Knee

Knee osteoarthritis (OA) leads to significant pain and disability, prompting new cell-based injections to lessen the symptoms. Biological therapies such as autologous microfragmented adipose tissue (AMAT) and a stromal vascular fraction (SVF) are a common source for harvesting mesenchymal and progenitor cells. Platelet-rich plasma (PRP) is associated with cytokines and growth factors. Recent studies have reported good clinical outcomes with AMAT, SVF, and PRP in knee osteoarthritis treatment. However, the preparation, processing, and application technique are vital to achieving satisfactory results. Many studies have examined outcomes after AMAT, SVF, or PRP injection, with encouraging results. Still, there is a lack of studies describing a technique that combines both methods, the timing, and the amount of SVF or PRP injected. This technical note's objective was to describe a standardized new technique composed of platelet and adipose stroma to treat knee osteoarthritis (OA) and the processing method.

Editorial Commentary: Point-of-Care Harvest and Application of Resident Stem Are Practical and Cost-Effective

Point-of-care harvest and application of residence stem cells are practical and cost-effective. Tissue formerly considered waste contains these biologically potent cells, and use of such tissue may represent a big part of biologics going forward. The practical application of orthobiologics has slowed because of 3 hurdles: the regulatory requirements of stem cell technologies; the energy, time, and money required to develop a clinical evidence base; and the expense that they present to patients and institutions. Orthobiologic technologies that are simple and cheap and that leverage tissues that are already readily available at the point of care (i.e., the surgical procedure) solve many of these challenges. Cell sources could include knee synovium, shoulder subacromial bursa, bone marrow aspirate, and anterior cruciate ligament injury effusion fluid and stump tissue. A current concern is that collagenase processing and culture expansion are steps resulting in regulatory hurdles in the United States.

Motorized Shaver Harvest Results in Similar Cell Yield and Characteristics Compared With Rongeur Biopsy During Arthroscopic Synovium-Derived Mesenchymal Stem Cell Harvest

PURPOSE

To compare cell yield and character of synovium-derived mesenchymal stem cell (SDMSC) harvested by 2 different techniques using rongeur and motorized shaver during knee arthroscopy.

METHODS

This study was performed in 15 patients undergoing partial meniscectomy. Two different techniques were used to harvest SDMSCs in each patient from the synovial membrane at 2 different locations overlying the anterior fat pad, each within 1 minute of harvest time. Cell yield and proliferation rates were evaluated. Cell surface marker analysis was done after passage 2 (P2). Trilineage differentiation potential was evaluated by real-time quantitative polymerase chain reaction and histology. Statistical analysis between the 2 methods was done using the Mann-Whitney U test.

RESULTS

Wet weight of total harvested tissue was 69.93 (± 20.02) mg versus 378.91 (± 168.87) mg for the rongeur and shaver group, respectively (P < .0001). Mononucleated cell yield was 3.32 (± 0.89) versus 3.18 (± 0.97) × 10³ cells/mg, respectively (P = .67). Fluorescence-activated cell sorting analysis revealed similar SDMSC-related cell surface marker expression levels in both groups, with positive expression for CD44, CD73, CD90, and CD105 and decreased expression for CD34 and CD45. Both groups showed similar trilineage differentiation potential in histology. Chondrogenic (SOX9, ACAN, COL2), adipogenic (LPL, PLIN1, PPAR-γ), and osteogenic (OCN, OSX, RUNX2) gene marker expression levels also were similar between both groups.

CONCLUSIONS

No difference was observed between rongeur biopsy and motorized shaver harvest methods regarding SDMSC yield and cell characteristics.

CLINICAL RELEVANCE

The current study shows that both rongeur and motorized shaver harvest are safe and effective methods for obtaining SDMSCs. Motorized shaver harvest results in higher volume of tissue acquisition per time, thereby leading to higher number of SDMSCs which may be useful during clinical application.

AMIC for traumatic focal osteochondral defect of the talar shoulder: a 5 years follow-up prospective cohort study

BACKGROUND

Autologous Matrix-Induced Chondrogenesis (AMIC) is addressed to osteochondral defects of the talus. However, evidence concerning the midterm efficacy and safety of AMIC are limited. This study assessed reliability and feasibility of AMIC at 60 months follow-up. We hypothesize that AMIC leads to good clinical outcome at midterm follow-up.

METHODS

Surgeries were approached with an arthrotomy via malleolar osteotomy. A resorbable porcine I/III collagen membrane (Chondro-Gide®, Geistlich Pharma AG, Wolhusen, Switzerland) was used. Patients were followed at 24 and 60 months. The primary outcome of interest was to analyse the Foot Function Index (FFI), and the subscale hindfoot of the American Orthopaedic Foot and Ankle Score (AOFAS). Complications such as failure, revision surgeries, graft delamination, and hypertrophy were also recorded. The secondary outcome of interest was to investigate the association between the clinical outcome and patient characteristics at admission.

RESULTS

Data from 19 patients were included. The mean age at admission was 47.3 ± 13.2 years, and the mean BMI 24.1 ± 4.9 kg/m². 53% (10 of 19 patients) were female. At a mean of 66.2 ± 11.6 months, the FFI decreased at 24-months follow-up of 22.5% (P = 0.003) and of further 1.3% (P = 0.8) at 60-months follow-up. AOFAS increased at 24-months follow-up of 17.2% (P = 0.003) and of further 3.4 (P = 0.2) at 60-months follow-up. There were two symptomatic recurrences within the follow-up in two patients. There was evidence of a strong positive association between FFI and AOFAS at baseline and the same scores last follow-up (P = 0.001 and P = 0.0002, respectively).

CONCLUSION

AMIC enhanced with cancellous bone graft demonstrated efficacy and feasibility for osteochondral defects of the talus at five years follow-up. The greatest improvement was evidenced within the first two years. These results suggest that clinical outcome is influenced by the preoperative status of the ankle. High quality studies involving a larger sample size are required to detect seldom complications and identify prognostic factors leading to better clinical outcome.

LEVEL OF EVIDENCE

II, prospective cohort study.

Increased expression of cyclooxygenase-2 in synovium tissues and synovial fluid from patients with knee osteoarthritis is associated with downregulated microRNA-758-3p expression

Cyclooxygenase-2 (COX-2) is a common factor in inflammation, and its specific regulatory mechanism has not been fully elucidated. The present study aimed to investigate COX-2 mRNA and protein expression levels in synovium tissues and synovial fluid from patients with knee osteoarthritis (KOA), and determine the molecular mechanism by which microRNA (miRNA/miR)-758 regulates KOA via COX-2. A total of 37 patients with KOA and 29 patients with acute knee trauma (control group) were enrolled in the present study. Reverse transcription-quantitative PCR analysis was performed to detect miR-758-3p and COX-2 mRNA expression, while western blotting and ELISA were performed to detect COX-2 protein expression in synovium and synovial fluid, respectively. The dual-luciferase reporter assay was performed to verify the interaction between miR-758-3p and the 3'-untraslated region (UTR) of COX-2 mRNA. Synovial cells were transfected with agomiR-758-3p, and the MTT assay was performed to assess cell proliferation. The results demonstrated that COX-2 expression was higher in patients with KOA than those with acute knee trauma. Conversely, miR-758-3p expression was lower in patients with KOA than those with acute knee trauma. Notably, miR-758-3p interacted with the 3'-UTR of COX-2 mRNA to regulate its expression. Overexpression of miR-758-3p inhibited the expression and release of COX-2, as well as the proliferation of human KOA synovial cells. Taken together, these results suggest that COX-2 expression is upregulated in synovium tissues and synovial fluid from patients with KOA, which is associated with downregulated miR-758-3p expression. In addition, miR-758-3p affects the proliferation of synovial cells and the expression of relevant proteins in these cells, thus promoting the occurrence and development of KOA.

Mesenchymal Stem Cells: Current Concepts in the Management of Inflammation in Osteoarthritis

Osteoarthritis (OA) has traditionally been known as a “wear and tear” disease, which is mainly characterized by the degradation of articular cartilage and changes in the subchondral bone. Despite the fact that OA is often thought of as a degenerative disease, the catabolic products of the cartilage matrix often promote inflammation by activating immune cells. Current OA treatment focuses on symptomatic treatment, with a primary focus on pain management, which does not promote cartilage regeneration or attenuate joint inflammation. Since articular cartilage have no ability to regenerate, thus regeneration of the tissue is one of the key targets of modern treatments for OA. Cell-based therapies are among the new therapeutic strategies for OA. Mesenchymal stem cells (MSCs) have been extensively researched as potential therapeutic agents in cell-based therapy of OA due to their ability to differentiate into chondrocytes and their immunomodulatory properties that can facilitate cartilage repair and regeneration. In this review, we emphasized current knowledge and future perspectives on the use of MSCs by targeting their regeneration potential and immunomodulatory effects in the treatment of OA.

Alterations in cartilage quantification before and after injections of mesenchymal stem cells into osteoarthritic knees

Several studies have reported improvement in knee pain following mesenchymal stem cell (MSC) injections for knee osteoarthritis (OA). We developed a novel 3D magnetic resonance imaging (MRI) analysis software program that provides “projected cartilage area ratios” for automatic detection of changes in cartilage amounts. The primary objective of this prospective interventional study was to compare alterations in the projected cartilage area ratio (thickness ≥ 1.5 mm) at the femoral posteromedial region between 30 weeks before and 30 weeks after synovial MSC injections. Secondary objectives were to assess the clinical scores and safety of MSC injections. Patients with OA who complained of knee pain underwent autologous synovial MSC injections into the knee at time 0 and again 15 weeks later. MRI examinations were performed at − 30, − 15, − 1, and 30 weeks. Patients showing < 3% decreases in the projected cartilage area ratio (thickness ≥ 1.5 mm) at the femoral the posteromedial region from − 30 weeks to − 15 weeks were excluded from the study. The Lysholm Knee Score, Knee Injury and Osteoarthritis Outcome Scale (KOOS), and Numerical Rating Scale (NRS) scores were evaluated at − 30, − 15, − 5, − 2, 0, 5, 10, 15, 20, 25, and 30 weeks. Five patients were excluded because 3D MRI analysis showed no cartilage loss at − 15 weeks. Ultimately, eight OA patients underwent MSC injections. The projected cartilage area ratio significantly decreased by 0.07 in the 30 weeks before MSC injections (p = 0.01), but no further decreases occurred in the 30 weeks after MSC injections. The projected cartilage area ratio at the femoral posteromedial region showed a significant difference between 30 weeks before and 30 weeks after MSC injections. The Lysholm Knee Score, KOOS, and NRS values improved significantly after the injections. MSC injection could not be ruled out as the cause of two adverse events: transient knee pain and itching in both hands. Fully automatic 3D MRI analysis showed that synovial MSC injections suppressed cartilage loss in patients with progressive OA.

Trial registration: Intraarticular injections of synovial stem cells for osteoarthritis of the knee (Number UMIN 000026732). Date of registration; June 1, 2017. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000029967.

Intra-articular Injection of Cell-laden 3D Microcryogels Empower Low-dose Cell Therapy for Osteoarthritis in a Rat Model

Intra-articular injection of mesenchymal stem cells (MSCs) in an osteoarthritic joint can help slow down cartilage destruction. However, cell survival and the efficiency of repair are generally low due to mechanical damage during injection and a high rate of cell loss. We, thus, investigated an improved strategy for cell delivery to an osteoarthritic joint through the use of three-dimensional (3D) microcryogels. MSCs were seeded into 3D microcryogels. The viability and proliferation of MSCs in microcryogels were determined over 5 d, and the phenotype of MSCs was confirmed through trilineage differentiation tests and flow cytometry. In Sprague Dawley rats with induced osteoarthritis (OA) of the knee joint, a single injection was made with the following groups: saline control, low-dose free MSCs (1 × 10⁵ cells), high-dose free MSCs (1 × 10⁶ cells), and microcryogels + MSCs (1 × 10⁵ cells). Cartilage degeneration was evaluated by macroscopic examination, micro-computed tomographic analysis, and histology. MSCs grown in microcryogels exhibited optimal viability and proliferation at 3 d with stable maintenance of phenotype in vitro. Microcryogels seeded with MSCs were, therefore, primed for 3 d before being used for in vivo experiments. At 4 and 8 wk, the microcryogels + MSCs and high-dose free MSC groups had significantly higher International Cartilage Repair Society macroscopic scores, histological evidence of more proteoglycan deposition and less cartilage loss accompanied by a lower Mankin score, and minimal radiographic evidence of osteoarthritic changes in the joint compared to the other two groups. In conclusion, intra-articular injection of cell-laden 3D microcryogels containing a low dose of MSCs can achieve similar effects as a high dose of free MSCs for OA in a rat model. Primed MSCs in 3D microcryogels can be considered as an improved delivery strategy for cell therapy in treating OA that minimizes cell dose while retaining therapeutic efficacy.

Autologous Chondrocyte Implantation and Mesenchymal Stem Cells for the Treatments of Chondral Defects of the Knee- A Systematic Review

BACKGROUND

There is still a lack of consensus about the best treatment of chondral defects of the knee. We conducted a systematic PRISMA review to evaluate clinical outcomes of Autologous Chondrocyte Implantation (ACI) and Mesenchymal Stem Cell (MSC) injections for the treatment of focal chondral defects of the knee.

METHODS

A systematic review of literature was performed according to the PRISMA guidelines. All the articles reporting data on ACI and MSC treatments for chondral defects of the knee were considered for inclusion. The main databases were accessed: PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar. The statistical analysis was performed using the Review Manager Software.

RESULTS

In the p-ACI group (987 knees), the Cincinnati Score improved by 18.94% (p=0.1), VAS by 38% (p=0.01), Tegner score by 19.11% (p=0.03), Lysholm score by 22.40% (p=0.01), IKCD by 27.36% (p=0.003). In the c-ACI group (444 knees), the Cincinnati Score improved by 23.80% (p=0.08), KOOS by 23.48% (p=0.03), VAS by 33.2% (p=0.005), IKDC by 33.30% (p=0.005). In the m-ACI group (599 knees), the Cincinnati Score improved by 26.80% (p=0.08), KOOS by 31.59% (p=0.1), VAS by 30.43% (p=0.4), Tegner score by 23.1% (p=0.002), Lysholm score by 31.14% (p=0.004), IKCD by 30.57% (p<0.001). In the MSCs group (291 knees), the KOOS improved by 29.7% (p=0.003), VAS by 41.89% (p<0.001), Tegner score by 25.81% (p=0.003), Lysholm score by 36.96% (p<0.001), IKCD by 30.57% (p=0.001).

CONCLUSION

Both ACI and MSC therapies can be considered as a concrete solution to treat focal chondral defects of the knee.

Meta-Analysis of Adipose Tissue Derived Cell-Based Therapy for the Treatment of Knee Osteoarthritis

Osteoarthritis (OA) is a degenerative disorder associated with cartilage loss and is a leading cause of disability around the world. In old age, the capacity of cartilage to regenerate is diminished. With an aging population, the burden of OA is set to rise. Currently, there is no definitive treatment for OA. However, cell-based therapies derived from adipose tissue are promising. A PRISMA systematic review was conducted employing four databases (MEDLINE, EMBASE, Cochrane, Web of Science) to identify all clinical studies that utilized adipose tissue derived mesenchymal stem cells (AMSCs) or stromal vascular fraction (SVF) for the treatment of knee OA. Eighteen studies were included, which met the inclusion criteria. Meta-analyses were conducted on fourteen of these studies, which all documented WOMAC scores after the administration of AMSCs. Pooled analysis revealed that cell-based treatments definitively improve WOMAC scores, post treatment. These improvements increased with time. The studies in this meta-analysis have established the safety and efficacy of both AMSC therapy and SVF therapy for knee OA in old adults and show that they reduce pain and improve knee function in symptomatic knee OA suggesting that they may be effective therapies to improve mobility in an aging population.

Harnessing adipose stem cell diversity in regenerative medicine

Since the first isolation of mesenchymal stem cells from lipoaspirate in the early 2000s, adipose tissue has been a darling of regenerative medicine. It is abundant, easy to access, and contains high concentrations of stem cells (ADSCs) exhibiting multipotency, proregenerative paracrine signaling, and immunomodulation-a winning combination for stem cell-based therapeutics. While basic science, preclinical and clinical findings back up the translational potential of ADSCs, the vast majority of these used cells from a single location-subcutaneous abdominal fat. New data highlight incredible diversity in the adipose morphology and function in different anatomical locations or depots. Even in isolation, ADSCs retain a memory of this diversity, suggesting that the optimal adipose source material for ADSC isolation may be application specific. This review discusses our current understanding of the heterogeneity in the adipose organ, how that heterogeneity translates into depot-specific ADSC characteristics, and how atypical ADSC populations might be harnessed for regenerative medicine applications. While our understanding of the breadth of ADSC heterogeneity is still in its infancy, clear trends are emerging for application-specific sourcing to improve regenerative outcomes.

Autologous stem cell therapy in knee osteoarthritis: a systematic review of randomised controlled trials

OBJECTIVE

Stem cell therapy is increasingly used for knee osteoarthritis (KOA). We aimed to review the evidence of autologous mesenchymal stem cell therapy on pain, function and severity on imaging in KOA.

DESIGN

Systematic review of randomised controlled trials (RCTs).

ELIGIBILITY CRITERIA

RCTs evaluating autologous mesenchymal stem cell (MSC) therapy on patient-reported outcome measures and disease severity.

DATA SOURCES

Seven databases were searched until 31 December 2020.

RISK OF BIAS AND DATA SYNTHESIS

Risk of bias was assessed using the ROB V.2. We used Grading of Recommendations Assessment, Development and Evaluation to appraise the certainty of the evidence. Data were synthesised descriptively.

RESULTS

Fourteen RCTs were included. A total of 408 patients with KOA received MSC therapy derived from bone marrow, adipose tissue or activated peripheral blood. After 1 year, 19 of 26 (73%) clinical outcome measures improved with MSCs compared with control. In the MSC group, patients improved by 1.8-4.4 points on the Visual Analogue Scale (0-10) and 18-32 points of the Knee Osteoarthritis Outcome Score (0-100). Four studies showed better disease severity on imaging after MSC compared with control at 1 year. Ten of 14 (71%) RCTs were at high risk of bias on all outcomes. No serious adverse events were reported after MSC therapy during a maximum of 4 years follow-up.

CONCLUSION

We found a positive effect of autologous MSC therapy compared with control treatments on patient-reported outcome measures, and disease severity. The certainty of this evidence was low to very low.

PROSPERO REGISTRATION NUMBER

CRD42019120506.

A Prospective Study Comparing Leukocyte-Poor Platelet-Rich Plasma Combined with Hyaluronic Acid and Autologous Microfragmented Adipose Tissue in Patients with Early Knee Osteoarthritis

The objective of this study was to compare the clinical efficacy of repeated doses of leucocyte-poor platelet-rich plasma (LP-PRP) plus hyaluronic acid (HA) to a single dose of autologous microfragmented adipose tissue (AMAT) injections in patients with early osteoarthritis (OA) symptoms. Eighty knees in 50 patients (mean age: 61.3 years) were randomly allocated into two equal groups in a nonblinded design and prospectively followed for 12 months. Group 1 received three intra-articular injections (1 month apart) using autologous LP-PRP+HA. Group 2 received a single dose of AMAT injection. Outcomes were measured by PROMs Tegner, Marx, visual analog scale, and Knee Injury and Osteoarthritis Outcome Score (KOOS) at 6 and 12 months. Both groups had significant clinical and functional improvement at 6 and 12 months. The differences between groups were statistically significant in Tegner score and KOOS symptoms (both P < 0.05) at 6 months in group 2. The test with statistically significant differences (P < 0.05) at 12 months was Tegner (P < 0.001), with group 2 having a higher median than group 1. LP-PRP+HA and AMAT lead to clinical and functional improvement at 6 and 12 months. AMAT showed better clinical results in Tegner and KOOS symptoms at 6 months and Tegner at 12 months. Understanding which therapy offers the most benefits with the least risk can significantly improve the quality of life for millions of people affected by OA. Long-term randomized controlled studies are needed to verify differences in efficacy.

Post-Adipose-Derived Stem Cells (ADSC) Stimulated by Collagen Type V (Col V) Mitigate the Progression of Osteoarthritic Rabbit Articular Cartilage

Collagen is essential for cartilage adhesion and formation. In the present study, histology, immunofluorescence, morphometry, and qRT-PCR suggested that adipose-derived stem cells (ADSCs) stimulated by type V collagen (Col V) induce a significant increase of type II collagen (Col II) in the degenerative area of surgical-induced osteoarthritic rabbit articular cartilage (OA). In vitro, the effects of Col V on the proliferation and differentiation of ADSC were investigated. The expression of the cartilage-related genes Col2a1 and Acan was significantly upregulated and Pou5fl was downregulated post-ADSC/Col V treatment. Post-ADSC/Col V treatment, in vivo analyses revealed that rabbits showed typical signs of osteoarthritic articular cartilage regeneration by hematoxylin and eosin (H&E) and Safranin O/Fast Green staining. Immunohistochemical staining demonstrated that the volume of Col II fibers and the expression of Col II protein were significantly increased, and apoptosis Fas ligand positive significantly decreased post-ADSC/Col V treatment. In conclusion, the expression of Col II was higher in rabbits with surgical-induced osteoarthritic articular cartilage; hence, ADSC/Col V may be a promising therapeutic target for OA treatment.