A dose response analysis of a specific bone marrow concentrate treatment protocol for knee osteoarthritis

The influence of cell and platelet number on clinical outcomes provided by a one-step scaffold transplantation with bone marrow concentrate for the treatment of osteochondral lesions of the talus

PURPOSE

The aim of this study was to investigate if the numbers of cells and platelets in the bone marrow aspirate concentrate (BMAC) added to a hyaluronic acid membrane influence the clinical outcome up to long-term follow-up in the treatment of osteochondral lesions of the talus (OLTs).

METHODS

A total of 102 patients with symptomatic OLTs underwent this one-step treatment. Eighty-five patients (53 men, 32 women, age 32.3 ± 10.6 years, lesion size 2.7 ± 1.6 cm2) were prospectively evaluated at baseline and at 2-5-10 years using the AOFAS ankle-hindfoot score, the NRS for pain, and the Tegner score. Satisfaction and failures were documented as well. Laboratory analysis of BMAC was performed for the count of mononucleated cells (MNCs) and platelets.

RESULTS

The AOFAS improved from baseline (59.1 ± 13.7) to the final follow-up (82.3 ± 14.9, p < 0.0005). NRS improved from 7.1 ± 1.1 at baseline to 3.9 ± 2.8 at the final follow-up (p < 0.0005). Tegner improved from a pre-op 2.0 median to 3.0 at the final follow-up (p < 0.0005), not reaching the pre-injury level. MNCs and platelets in BMAC were 148.2 ± 54.2 × 109/L and 454.3 ± 277.5 × 109/L, respectively. MNCs correlated with NRS at 2 years (p = 0.018; rho=-0.260). However, MNCs number, as well as platelet number, did not influence the improvement from baseline of the clinical scores at all follow-up evaluations.

CONCLUSION

This study demonstrated, in a large series of patients evaluated up to a long-term follow-up, that the number of MNCs and platelets present in BMAC does not influence the overall clinical outcomes in patients affected by OLTs treated with a one-step hyaluronic acid scaffold implantation augmented with BMAC.

LEVEL OF EVIDENCE

IV.

Safety and Efficacy of Bone-Marrow Aspirate Concentrate in Hip Osteoarthritis: A Systematic Review of Current Clinical Evidence

Introduction

Hip osteoarthritis (OA) is one of the leading causes of disability and morbidity worldwide. It is estimated to affect 9.2% individuals globally with age over 45 years. Conventional treatment modalities have limitations and side-effects. To overcome these limitations, over the last decade, there has been an increased interest in the use of orthobiologics derived from autologous sources including platelet-rich plasma (PRP), bone-marrow aspirate concentrate (BMAC) and adipose tissue derived formulations. This review qualitatively presents the in-vitro, pre-clinical, clinical and on-going clinical studies exploring the safety and efficacy of BMAC for management of hip OA.

Materials and methods

The electronic database search was done through PubMed, Embase, Web of Science, Scopus, ProQuest and Google Scholar till February 2024. The search terms used were "osteoarthritis" OR "hip osteoarthritis" OR "orthobiologics" OR "efficacy or use of orthobiologic treatment" OR "bone-marrow concentrate" OR "bone-marrow aspirate concentrate", AND "BMAC". The inclusion criteria were clinical studies of any level of evidence written in the English language, published till February 2024, evaluating the safety and efficacy of intra-articular administration of BMAC for the management of hip OA.

Results

A total of 5 studies were included in this review for qualitative data synthesis. The total number of patients who participated in the study was 182, ranging from 4 to 112 in a single study. No adverse events were reported throughout the duration of the study. In addition, intra-articular administration of BMAC led to reduced pain, and improved function and overall quality of life (QoL).

Conclusion

The results from this review demonstrated that administration of BMAC is safe and potentially efficacious in terms of reducing pain, improving function and overall QoL of patients with hip OA in short- and mid-term average follow-up based on the included studies. Nonetheless, more adequately powered, multi-center, prospective, double-blind, non-randomized and randomized controlled trials with long-term follow-up are warranted to establish long-term safety and efficacy of BMAC for management of hip OA and justify its routine clinical use.

The Efficacy of Bone Marrow Stem Cell Therapy in Hip Osteoarthritis: A Scoping Review

Background

Hip osteoarthritis (HOA) is a prevalent degenerative joint disease with various treatment approaches. Biological agents, such as bone-marrow derived stem cells (BM-MSC) therapy, have recently been proposed as a treatment option in the management of HOA.

Purpose

We sought to further analyze the use of BM-MSC therapy by investigating the following questions. What is the standard preparation and practice? Does a dose response exist between stem cell therapy and clinical outcome? Does BM-MSC therapy alone produce effective clinical outcomes?

Methods

We conducted a scoping review using the Methodological Expectations of Cochrane Intervention Reviews Manual and the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines for scoping reviews. A comprehensive search of PubMed, Embase, Cochrane CENTRAL, Scopus, SPORTDiscus, Cumulative Index to Nursing and Allied Health Literature, and Web of Science Core Collection was performed in June 2023 of studies using exclusively BM-MSC injections for the treatment of HOA. Study characteristic, injection preparation and dosage, clinical outcome measures, and adverse effect data were extracted and interpreted by 3 reviewers.

Results

Seven studies with a total of 72 patients met the inclusion criteria. Clinical outcome following intra-articular injection of BM-MSCs was measured using the numerical pain scale, the Western Ontario and McMaster Universities Osteoarthritis Index, the visual analogue scale, and other scores, all of which showed reduction in pain and increase in functional ability across studies.

Conclusions

This scoping review found that the efficacy of BM-MSC therapy alone in the treatment of HOA appeared beneficial, improving clinical outcomes in each study. All 7 studies used "low-dose" injections with variable follow-up times; thus, a clear dose-response relationship cannot be drawn. Future studies using high doses and analyzing long-term effects of BM-MSC injections in HOA are needed.

Percutaneous bone marrow concentrate and platelet products versus exercise therapy for the treatment of rotator cuff tears: a randomized controlled, crossover trial with 2-year follow-up

BACKGROUND

Surgical repair is recommended for the treatment of high-grade partial and full thickness rotator cuff tears, although evidence shows surgery is not necessarily superior to non-surgical therapy. The purpose of this study was to compare percutaneous orthobiologic treatment to a home exercise therapy program for supraspinatus tears.

METHODS

In this randomized-controlled, crossover design, participants with a torn supraspinatus tendon received either 'BMC treatment', consisting of a combination of autologous bone marrow concentrate (BMC) and platelet products, or underwent a home exercise therapy program. After three months, patients randomized to exercise therapy could crossover to receive BMC treatment if not satisfied with shoulder progression. Patient-reported outcomes of Numeric Pain Scale (NPS), Disabilities of the Arm, Shoulder, and Hand, (DASH), and a modified Single Assessment Numeric Evaluation (SANE) were collected at 1, 3, 6, 12, and 24 months. Pre- and post-treatment MRI were assessed using the Snyder Classification system.

RESULTS

Fifty-one patients were enrolled and randomized to the BMC treatment group (n = 34) or the exercise therapy group (n = 17). Significantly greater improvement in median ΔDASH, ΔNPS, and SANE scores were reported by the BMC treatment group compared to the exercise therapy group (-11.7 vs -3.8, P = 0.01; -2.0 vs 0.5, P = 0.004; and 50.0 vs 0.0, P < 0.001; respectively) after three months. Patient-reported outcomes continued to progress through the study's two-year follow-up period without a serious adverse event. Of patients with both pre- and post-treatment MRIs, a majority (73%) showed evidence of healing post-BMC treatment.

CONCLUSIONS

Patients reported significantly greater changes in function, pain, and overall improvement following BMC treatment compared to exercise therapy for high grade partial and full thickness supraspinatus tears.

TRIAL REGISTRATION

This protocol was registered with www.

CLINICALTRIALS

gov (NCT01788683; 11/02/2013).

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.

Management of chondral and osteochondral lesions of the hip : A comprehensive review

Chondral and osteochondral lesions encompass several acute or chronic defects of the articular cartilage and/or subchondral bone. These lesions can result from several different diseases and injuries, including osteochondritis dissecans, osteochondral defects, osteochondral fractures, subchondral bone osteonecrosis, and insufficiency fractures. As the cartilage has a low capacity for regeneration and self-repair, these lesions can progress to osteoarthritis. This study provides a comprehensive overview of the subject matter that it covers. PubMed, Scopus and Google Scholar were accessed using the following keywords: "chondral lesions/defects of the femoral head", "chondral/cartilage lesions/defects of the acetabulum", "chondral/cartilage lesions/defects of the hip", "osteochondral lesions of the femoral head", "osteochondral lesions of the acetabulum", "osteochondral lesions of the hip", "osteochondritis dissecans," "early osteoarthritis of the hip," and "early stage avascular necrosis". Hip osteochondral injuries can cause significant damage to the articular surface and diminish the quality of life. It can be difficult to treat such injuries, especially in patients who are young and active. Several methods are used to treat chondral and osteochondral injuries of the hip, such as mesenchymal stem cells and cell-based treatment, surgical repair, and microfractures. Realignment of bony anatomy may also be necessary for optimal outcomes. Despite several treatments being successful, there is a lack of head-to-head comparisons and large sample size studies in the current literature. Additional research will be required to provide appropriate clinical recommendations for treating chondral/osteochondral injuries of the hip joint.

Near-infrared light-controlled kartogenin delivery of multifunctional Prussian blue nanocomposites for cartilage defect repair

Articular cartilage injury repair remains a challenge for clinicians and researchers. Mesenchymal stem cells (MSCs) have multiple differentiation potentials and can be induced to differentiate into the chondrogenic lineage for cartilage defect repair; however, the insufficient capacity of chondrogenic differentiation and excess reactive oxygen species (ROS)-mediated oxidative stress, which always lead to differentiation into hypertrophic chondrocytes, still need to be resolved. Accordingly, kartogenin (KGN), which can promote chondrogenic differentiation of MSCs, has shown promise in promoting infected cartilage repair. However, realizing controllable release to prolong its action time and avoid hypertrophic differentiation is critical. We herein developed a mesoporous Prussian blue nanoparticle (mPB)-based near-infrared (NIR) light-responsive controlled nanosystem. KGN was encapsulated in temperature-stimulated responsive phase change materials (PCMs), which were used as excellent gating materials (KGN-PCM@mPBs). In addition, the mPBs could efficiently scavenge ROS by their enzyme-like antioxidative activities. Our study demonstrates that the nanocomposites could efficiently promote chondrogenic differentiation and successfully inhibit the hypertrophic differentiation of MSCs. By intra-articular injection of KGN-PCM@mPBs and NIR-triggered precisely controlled release, satisfactory cartilage repair effects can be achieved in a rat chondral defect model. Thus, this constructed NIR-mediated KGN-PCM@mPB nanoplatform may represent an effective cartilage repair strategy with satisfactory biosafety in clinical applications.

Intra-articular Injection of Bone Marrow Concentrate for Treatment of Patellofemoral Osteoarthritis: Preliminary Results Utilizing an Ultrasound-Guided Marrow Harvesting Technique

OBJECTIVE

To assess the effectiveness of intra-articular injection of bone marrow concentrate (BMC) under ultrasound (US) guidance in the treatment of patellofemoral osteoarthritis (OA), with clinical and volumetric magnetic resonance (MR) imaging follow-up.

METHODS

This retrospective study included 96 consecutive patients referred for US-guided intra-articular injection of BMC for symptomatic patellofemoral OA for which conservative treatment had failed. A control group of 21 patients with symptomatic patellofemoral OA was included for comparison. Data on International Knee Documentation Committee (IKDC), Visual Analog Scale (VAS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores as well as volumetric MR imaging (using T2 mapping sequence) were collected before and 12 months after injection, and the results were compared.

RESULTS

No technical adverse events were noted during bone marrow aspiration, BMC preparation, or intra-articular injection of BMC. No clinical adverse events were reported during long-term follow-up. All mean scores improved between baseline and 12 months after intra-articular injection of BMC (VAS 5.5 to 3.6, P < .0001; WOMAC 36.8 to 22.2, P < .0001; and IKDC 41.8 to 58.2, P < .0001). MR imaging at 1 year of follow-up after BMC treatment showed no statistically significant difference in hyaline cartilage volume compared with that at the baseline (P = .690), suggesting stabilization of the cartilage degradation process. In contrast, the group of untreated patients showed a significant decrease in the cartilage volume (P = .001), corresponding to a cartilage loss of 6.9%.

CONCLUSIONS

The results suggest that intra-articular injection of BMC under US guidance could be a promising option for the treatment of symptomatic patellofemoral OA and could promote the preservation of healthy residual cartilage volume.

Intra-Articular Mesenchymal Stem Cell Injection for Knee Osteoarthritis: Mechanisms and Clinical Evidence

Knee osteoarthritis presents higher incidences than other joints, with increased prevalence during aging. It is a progressive process and may eventually lead to disability. Mesenchymal stem cells (MSCs) are expected to repair damaged issues due to trilineage potential, trophic effects, and immunomodulatory properties of MSCs. Intra-articular MSC injection was reported to treat knee osteoarthritis in many studies. This review focuses on several issues of intra-articular MSC injection for knee osteoarthritis, including doses of MSCs applied for injection and the possibility of cartilage regeneration following MSC injection. Intra-articular MSC injection induced hyaline-like cartilage regeneration, which could be seen by arthroscopy in several studies. Additionally, anatomical, biomechanical, and biochemical changes during aging and other causes participate in the development of knee osteoarthritis. Conversely, appropriate intervention based on these anatomical, biomechanical, biochemical, and functional properties and their interactions may postpone the progress of knee OA and facilitate cartilage repair induced by MSC injection. Hence, post-injection rehabilitation programs and related mechanisms are discussed.

Short-Term Efficacy of Using a Novel Low-Volume Bone Marrow Aspiration Technique to Treat Knee Osteoarthritis: A Retrospective Cohort Study

BACKGROUND

Intra-articular bone marrow concentrate (BMC) and aspirate (BMA) injections have been used with mixed results to treat osteoarthritis (OA). Given the various aspiration and concentration methods available for preparing bone marrow, more data are needed to identify the optimal bone marrow harvesting techniques to treat OA.

METHODS

This retrospective cohort study examined the effect of using low-volume BMAs harvested using the Marrow Cellution™ (MC) device on 160 patients (262 knees) suffering from pain due to knee OA, KL grades 2-4, that did not respond to conservative treatment. Changes in visual analog scores (VAS) for overall daily activity were examined over a six-month time frame in these patients (63.5 ± 0.97 years of age; 48.1% male). In addition, changes in the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Patient Global Impression of Change (PGIC scores) were examined over the same time frame in a smaller subset of patients (95 patients including 172 knees).

RESULTS

There was a statistically significant improvement in VAS scores for overall daily activity 6 months postprocedure in the study population, 7.29 ± 0.27 vs. 3.76 ± 0.34 (p < 0.0001), as well as statistically significant improvements in WOMAC scores, 49.3 ± 4.27 vs. 66.3 ± 4.08 (p < 0.0001). On the individual level, 71% of the cases displayed VAS improvements and 61% of the cases displayed WOMAC improvements that exceeded levels previous studies determined to be the minimal clinically important difference (MCID) for knee OA treatments. The improvements in WOMAC scores were also seen in both the WOMAC pain subscore, 52.2 ± 4.39 vs. 72.2 ± 4.36 (p < 0.0001) and the WOMAC function subscore, 51.6 ± 4.67 vs. 69.0 ± 4.36 (p < 0.0001). In addition, the PGIC scores measuring patient satisfaction improved from 4.03 ± 0.26 at 6 weeks postprocedure to 4.65 ± 0.28 at 6 months postprocedure (p < 0.0001).

CONCLUSIONS

Knee OA patients treated with MC BMA intra-articular injections exhibited significant reductions in VAS pain scores and significant improvements in WOMAC scores that exceeded the minimal clinically important difference thresholds. In addition, reductions in VAS pain scores and improvements in WOMAC scores correlated with higher PGIC scores.

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.

•

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.

Mendelian Randomization Studies of Lifestyle-Related Risk Factors for Osteoarthritis: A PRISMA Review and Meta-Analysis

Risk factors for osteoarthritis (OA) often exert effects over protracted time-courses. Mendelian randomization (MR) studies therefore have an advantage over conventional observational studies when studying the causal effect of long-term lifestyle-related risk factors on OA. However, given the heterogeneous design of existing MR studies on OA, the reported causal estimates of these effects remain inconsistent, thus obscuring the true extent of the biological effects of OA lifestyle-risk factors. We conducted a PRISMA systematic review and specifically included MR studies that investigated the causal effect between lifestyle-related risk factors and OA, where causal estimates for various lifestyle factors were pooled for meta-analysis. Quality of studies was assessed according to STROBE-MR guidelines. A total of 1576 studies were evaluated and 23 were included. Overall, the studies included were of high quality and had a low risk of bias. Our meta-analysis demonstrates the positive causal effect of BMI (ORIVW-random effects 1.49 [1.23-1.80]) and negative causal effects of serum calcium (ORIVW-random effects 0.69 [0.57-0.83]) and LDL levels (ORIVW-random effects 0.93 [0.90-0.96]) on OA. Despite the heterogeneous designs and estimates of causal effects provided by various MR studies, our meta-analysis suggests that lifestyle-related risk factors in the form of BMI, serum calcium, and LDL have true biological effects on the development of OA.

Percutaneous autologous bone marrow concentrate for knee osteoarthritis: patient-reported outcomes and progenitor cell content

PURPOSE

Knee osteoarthritis (OA) is a common, progressively debilitating joint disease, and the intra-articular injection of autologous bone marrow concentrate (BMC) may offer a minimally invasive method of harnessing the body's own connective tissue progenitor cells to counteract accompanying degenerative effects of the disease. However, the extent to which the progenitor cell content of BMC influences treatment outcomes is unclear. We sought to determine whether patient-reported outcome measures associated with BMC treatment for knee OA are related to the concentration of progenitor cells provided.

METHODS

In the present study, 65 patients (72 knees) underwent treatment for knee OA with autologous BMC and self-reported their outcomes for up to one year using follow-up questionnaires tracking function, pain, and percent improvement. A small fraction of each patient's BMC sample was reserved for quantification with a haematological analyzer and cryopreserved for subsequent analysis of potential connective tissue progenitor cells using a colony-forming unit fibroblast (CFU-F) assay.

RESULTS

Patients reported significant increases in function and overall percent improvement in addition to decreases in pain relative to baseline levels following treatment with autologous BMC that persisted through 12 months. Patients reporting improved outcomes (46 of 72 knees) received BMC injections having higher CFU-F concentrations than non-responding patients (21.1×10³ ± 12.4×10³ vs 14.3×10³ ± 7.0 x10³ CFU-F per mL). A progenitor cell concentration of 18×10³ CFU-F per mL of BMC was found to best differentiate responders from non-responders.

CONCLUSION

This study provides supportive evidence for using autologous BMC in the minimally invasive treatment of knee OA and suggests that increased progenitor cell content leads to improved treatment outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03011398, 1/7/17.

Bone marrow aspirate concentrate quality is affected by age and harvest site

PURPOSE

To compare the number and properties of bone marrow stromal cells (BMSCs) collected from bone marrow aspirate concentrate (BMAC) obtained from different harvest sites and from patients of different ages.

METHODS

BMAC was obtained from two groups of patients based on age (n = 10 per group): 19.0 ± 2.7 years for the younger and 56.8 ± 12.5 for the older group. In the latter, BMAC was obtained from both iliac crest and proximal tibia for a donor-matched analysis. Mononucleated cell count and CFU-F assay were performed, together with phenotype characterization of BMSCs from iliac crest and proximal tibia, the study of chondrogenic and osteogenic differentiation capacity, histological staining and spectrophotometric quantification, and the analysis of mRNAs expression.

RESULTS

Cells derived from iliac crest and proximal tibia showed the same phenotypic pattern at flow cytometry, as well as similar chondrogenic and osteogenic potential. However, a significantly higher number of mononuclear cells per ml was observed in younger patients (3.8 ± 1.8 × 10⁷) compared to older patients (1.2 ± 0.8 × 10⁷) (p < 0.0005). The latter yield, obtained from the iliac crest, was significantly higher than resulting from the BMAC harvested from the proximal tibia in the same group of patients (0.3 ± 0.2 × 10⁷, p < 0.0005). This result was confirmed by the CFU-F analysis at day 10 (15.9 ± 19.4 vs 0.6 ± 1.0, p = 0.001) and day-20 (21.7 ± 23.0 vs 2.9 ± 4.2, p = 0.006).

CONCLUSION

Harvest site and age can affect the quality of BMAC. BMSCs obtained from iliac crest and proximal tibia present comparable mesenchymal markers expression as well as osteogenic and chondrogenic differentiation potential, but iliac crest BMAC presents a four times higher number of mononucleated cells with significantly higher clonogenic capacity compared to the tibia. BMAC of younger patients also had a three-time higher number of mononucleated cells. The identification of BMAC characteristics could help to optimize its preparation and to identify the most suitable indications for this orthobiologic treatment in the clinical practice.

Autologous Immune Cell-Based Regenerative Therapies to Treat Vasculogenic Erectile Dysfunction: Is the Immuno-Centric Revolution Ready for the Prime Time?

About 35% of patients affected by erectile dysfunction (ED) do not respond to oral phosphodiesterase-5 inhibitors (PDE5i) and more severe vasculogenic refractory ED affects diabetic patients. Innovative approaches, such as regenerative therapies, including stem cell therapy (SCT) and platelet-rich plasma (PRP), are currently under investigation. Recent data point out that the regenerative capacity of stem cells is strongly influenced by local immune responses, with macrophages playing a pivotal role in the injury response and as a coordinator of tissue regeneration, suggesting that control of the immune response could be an appealing approach in regenerative medicine. A new generation of autologous cell therapy based on immune cells instead of stem cells, which could change regenerative medicine for good, is discussed. Increasing safety and efficacy data are coming from clinical trials using peripheral blood mononuclear cells to treat no-option critical limb ischemia and diabetic foot. In this review, ongoing phase 1/phase 2 stem cell clinical trials are discussed. In addition, we examine the mechanism of action and rationale, as well as propose a new generation of regenerative therapies, evolving from typical stem cell or growth factor to immune cell-based medicine, based on autologous peripheral blood mononuclear cells (PBMNC) concentrates for the treatment of ED.

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.

Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 2 Years: A Prospective Randomized Trial

BACKGROUND

Autologous platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMC) are being used clinically as therapeutic agents for the treatment of knee osteoarthritis.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare the efficacy of BMC and PRP on pain and function in patients with knee osteoarthritis up to 24 months after injection. It was hypothesized that patients receiving BMC would have better sustained outcomes than those receiving PRP.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A total of 90 participants aged between 18 and 80 years with symptomatic knee osteoarthritis (Kellgren-Lawrence grades 1-3) were randomized into 2 study groups: PRP and BMC. Both groups completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and subjective International Knee Documentation Committee (IKDC) questionnaire before and 1, 3, 6, 9, 12, 18, and 24 months after a single intra-articular injection of leukocyte-rich PRP or BMC. A linear mixed-effects model was performed to quantify the effects over time and the difference between the groups. This model has the random effect for time to assess the extent in which the change over time differs from one person to another.

RESULTS

An overall 84 patients completed questionnaires from baseline to 12 months; however, 17 patients (n = 9; PRP group) were lost to follow-up at 18 months and 25 (n = 13; PRP group) at 24 months. There were no statistically significant differences in IKDC (P = .909; 95% CI, -6.26 to 7.03) or WOMAC (P = .789; 95% CI, -6.26 to 4.77) scores over time between the groups. Both groups had significantly improved IKDC (P < .001; 95% CI, 0.275-0.596) and WOMAC (P = .001; 95% CI, -0.41 to -0.13) scores from baseline to 24 months after the injection. These improvements plateaued at 3 months and were sustained for 24 months after the injection, with no difference between PRP and BMC at any time point.

CONCLUSIONS

For the treatment of osteoarthritis, PRP and BMC performed similarly out to 24 months. BMC was not superior to PRP.

REGISTRATION

NCT03289416 (ClincalTrials.gov identifier).

Impact of the Process Variables on the Yield of Mesenchymal Stromal Cells from Bone Marrow Aspirate Concentrate

Human bone marrow (BM) has been highlighted as a promising source of mesenchymal stromal cells (MSCs) containing various growth factors and cytokines that can be potentially utilized in regenerative procedures involving cartilage and bone. However, the proportion of MSCs in the nucleated cell population of BM is only around 0.001% to 0.01% thereby making the harvesting and processing technique crucial for obtaining optimal results upon its use in various regenerative processes. Although several studies in the literature have given encouraging results on the utility of BM aspiration concentrate (BMAC) in various regenerative procedures, there is a lack of consensus concerning the harvesting variables such as choice of anesthetic agent to be used, site of harvest, size of the syringe to be used, anticoagulant of choice, and processing variables such as centrifugation time, and speed. In this review article, we aim to discuss the variables in the harvesting and processing technique of BMAC and their impact on the yield of MSCs in the final concentrate obtained from them.

Assessment of Clinical, Tissue, and Cell-Level Metrics Identify Four Biologically Distinct Knee Osteoarthritis Patient Phenotypes

OBJECTIVE

Clinical heterogeneity of primary osteoarthritis (OA) is a major challenge in understanding pathogenesis and development of targeted therapeutic strategies. This study aims to (1) identify OA patient subgroups phenotypes and (2) determine predictors of OA severity and cartilage-derived stem/progenitor concentration using clinical-, tissue-, and cell- level metrics.

DESIGN

Cartilage, synovium (SYN) and infrapatellar fatpad (IPFP) were collected from 90 total knee arthroplasty patients. Clinical metrics (patient demographics, radiograph-based joint space width (JSW), Kellgren and Lawrence score (KL)), tissue metrics (cartilage histopathology grade, glycosaminoglycans (GAGs)) and cell-based metrics (cartilage-, SYN-, and IPFP-derived cell concentration ([Cell], cells/mg), connective tissue progenitor (CTP) prevalence (PCTP, CTPs/million cells plated), CTP concentration, [CTP], CTPs/mg)) were assessed using k-mean clustering and linear regression model.

RESULTS

Four patient subgroups were identified. Clusters 1 and 2 comprised of younger, high body mass index (BMI) patients with healthier cartilage, where Cluster 1 had high CTP in cartilage, SYN, and IPFP, and Cluster 2 had low [CTP] in cartilage, SYN, and IPFP. Clusters 3 and 4 comprised of older, low BMI patients with diseased cartilage where Cluster 3 had low [CTP] in SYN, IPFP but high [CTP] in cartilage, and Cluster 4 had high [CTP] in SYN, IPFP but low [CTP] in cartilage. Age (r = 0.23, P = 0.026), JSW (r = 0.28, P = 0.007), KL (r = 0.26, P = 0.012), GAG/mg cartilage tissue (r = -0.31, P = 0.007), and SYN-derived [Cell] (r = 0.25, P = 0.049) were weak but significant predictors of OA severity. Cartilage-derived [Cell] (r = 0.38, P < 0.001) and PCTP (r = 0.9, P < 0.001) were moderate/strong predictors of cartilage-derived [CTP].

CONCLUSION

Initial findings suggests the presence of OA patient subgroups that could define opportunities for more targeted patient-specific approaches to prevention and treatment.

Intra-articular injection of autologous bone marrow aspirate concentrate in the treatment of osteoarthritis of the thumb first carpometacarpal joint: A pilot study

This study aimed to evaluate the effect of bone marrow aspirate concentrate (BMAC) in the treatment of osteoarthritis of the thumb first carpometacarpal joint. Injections were carried out in 27 thumbs. According to the Dell classification, there were 2 stage I, 11 stage II, 13 stage III and 1 stage IV cases. The bone marrow was aspirated from the iliac crest, concentrated by centrifugation, and injected under fluoroscopic control into the pathological thumb. Results were assessed at a mean 16 months' follow-up (range, 8-26). Clinical evaluation comprised QuickDASH and PRWE scores, pain at rest on a numerical analog scale (NAS), and thumb column abduction on goniometry. QuickDASH and PRWE scores were 59 (range, 27-82) and 88 range, 37-125) preoperatively and 29 (range, 0-64) and 50 (range, 1-99) postoperatively, respectively. Mean pain at rest on NAS improved from 7 (range, 1-10) to 4 (range, 0-9). Thumb abduction improved by a mean 18° over preoperative data. No postoperative complications were found. Two patients had to be operated on for inefficacy of injection. This is the first article presenting the effect of an intra-articular injection of BMAC in the thumb first carpometacarpal joint and the results were encouraging. Many patients showed improved quality of life and pain relief. These injections appear to be an effective means of postponing surgery.

Patient Age and Cell Concentration Influence Prevalence and Concentration of Progenitors in Bone Marrow Aspirates: An Analysis of 436 Patients

BACKGROUND

Connective tissue progenitors (CTPs) resident in native tissues serve as biological building blocks in tissue repair and remodeling processes. Methods for analysis and reporting on CTP quantity and quality are essential for defining optimal cell sources and donor characteristics and the impact of cell processing methods for cell therapy applications. The present study examines the influence of donor characteristics and cell concentration (nucleated cells/mL) on CTP prevalence (CTPs/million nucleated cells) and CTP concentration (CTPs/mL) in bone marrow aspirates (BMAs).

METHODS

Iliac crest bone marrow was aspirated from 436 patients during elective total knee or hip arthroplasty. Bone marrow-derived nucleated cells were plated at a density of 1.19 × 105 cells/cm2. Colony-forming unit analysis was performed on day 6.

RESULTS

Large variation was seen between donors. Age (p < 0.05) and cell concentration (p < 0.001) significantly influenced CTP prevalence and CTP concentration. For every 1-year increase in age, the odds of having at least an average CTP prevalence and CTP concentration decreased by 1.5% and 1.6%, respectively. For every 1 million cells/mL increase in cell concentration, the odds of having at least an average CTP prevalence and CTP concentration increased by 2.2% and 7.9%, respectively. Sex, race, body mass index (BMI), and the presence of osteoporosis did not influence CTP prevalence or CTP concentration.

CONCLUSIONS

BMA-derived CTPs were obtained from all patient groups. CTP prevalence and CTP concentration decreased with age. Cell concentration decreased with age and positively correlated with total CTP prevalence and CTP concentration. The mean CTP concentration in patients >60 years of age was a third of the CTP concentration in patients <30 years of age.

CLINICAL RELEVANCE

Proper BMA techniques are necessary to obtain a high-quality yield and composition of cells and CTPs. The reduced CTP concentration and CTP prevalence in the elderly may be mitigated by the use of cell processing methods that increase CTP concentration and CTP prevalence (e.g., by removing red blood cells, serum, and non-CTPs or by increasing aspirate volumes). Cell concentration in the BMA can be measured at the point of care and is an appropriate initial assessment of the quality of BMA.

The safety and effectiveness of bone marrow concentrate injection for knee and hip osteoarthritis: a Canadian cohort

Aim: Describe the safety and effectiveness of intra-articular bone marrow concentrate (BMC) injection to treat knee and/or hip osteoarthritis (OA) in a Canadian cohort. Materials & methods: A total of 112 patients with refractory OA received a single intra-articular injection of BMC into their knee(s) and/or hip(s). Pain, disability and quality of life were prospectively assessed prior to and 3, 6 and 12 months post-injection. Results: Outcome scores were significantly improved at all time points post-BMC injection with maximal improvement observed at 3-6 months. Improvements were unrelated to patient age, sex or radiographic OA severity. The complication rate was <2%. Interpretation: In this Canadian cohort, knee/hip OA treated with a single BMC injection resulted in significant improvements in pain, disability and quality of life and a low complication rate.

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.

Bone marrow concentrate injections for the treatment of osteoarthritis: evidence from preclinical findings to the clinical application

PURPOSE

To investigate the available literature on the use of bone marrow aspirate concentrate (BMAC) and summarize the current evidence supporting its potential for the injective treatment of joints affected by osteoarthritis (OA).

METHODS

A systematic literature search was conducted on three electronic databases (PubMed, Embase, and Cochrane Library) in April 2020, using the following string: "((bone marrow concentrate) OR (BMC) OR (bone marrow aspirate concentrate) OR (BMAC)) AND (osteoarthritis)", and inclusion criteria: clinical and preclinical (animal) studies of any level of evidence, written in English language, and evaluating the intra-articular or subchondral use of BMAC for the injective treatment of OA joints.

RESULTS

The publication trend remarkably increased over time. A total of 22 studies were included in the qualitative data synthesis: four preclinical studies and 18 clinical studies, for a total number of 4626 patients. Safety was documented by all studies, with a low number of adverse events. An overall improvement in pain and function was documented in most of the studies, but the clinical studies present significant heterogeneity, few patients, short-term follow-up, and overall poor methodology.

CONCLUSION

There is a growing interest in the field of BMAC injections for the treatment of OA, with promising results in preclinical and clinical studies in terms of safety and effectiveness. Nevertheless, the current knowledge is still preliminary. Preclinical research is still needed to optimize BMAC use, as well as high-level large controlled trials to better understand the real potential of BMAC injections for the treatment of patients affected by OA.

Bone marrow in orthopaedics (part II): a three hundred and seventy million-year saga from the Devonian to the coronavirus disease 2019 pandemic-osteonecrosis; transplantation; "human chimera"; stem cells, bioreactors, and coronavirus disease

PURPOSE

Three hundred seventy million years ago, bone marrow appeared in skeleton of a fish. More than one hundred years ago, the concept of bone marrow transplantation was proposed to treat human diseases. During the last five decades, this concept became a reality first in hematology and later for orthopaedic diseases.

MATERIAL AND METHODS

These advances were possible due to the comprehension of the three major components of bone marrow: the fat part, the haematologic part, and the stroma part. Each part has a different history, but the three parts are linked in physiology as in history.

RESULTS

During many centuries, bone marrow was considered just as food; however, one hundred years ago, the concept of bone marrow transplantation to treat humans was proposed by the French physician Brown-Séquard. During the last five decades, this concept became a reality first in haematology and later for orthopaedic diseases. Transferring what was known from experimental animal models to humans was met with many challenges, the atomic bomb research, and many deaths. Yet through the recognition and subsequent understanding of fundamental processes, medical resiliency, and the determination of a few pioneers, local bone marrow transplantation in orthopaedic surgery became a therapeutic option first for a limited number of diseases and patients. Over the last two decades, mesenchymal stromal cells (MSCs) have been the focus of intense research by acadaemia and industry due to their unique features. MSCs can be easily isolated and expanded through in vitro culture by taking full advantage of their self-renewing capacity. In addition, MSCs exert immunomodulatory effects and can be differentiated into various lineages, which makes them highly attractive for clinical applications in cell-based therapies.

CONCLUSION

In this review, we attempted to provide a historical overview of bone marrow history, MSC discovery, characterization, and the first clinical studies conducted.

Bone Marrow Concentrate Injection Treatment Improves Short-term Outcomes in Symptomatic Hip Osteoarthritis Patients: A Pilot Study

BACKGROUND

Osteoarthritis (OA) is one of the leading causes of disability in the United States, the hip being the second most affected weightbearing joint. Autologous bone marrow concentrate (BMC) is a promising alternative therapy to conventional treatments, with the potential to mitigate inflammation and improve joint function.

PURPOSE

To investigate the effectiveness of a single intra-articular BMC injection for patients with symptomatic hip OA.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 24 patients diagnosed with symptomatic hip OA who elected to undergo a single BMC injection were prospectively enrolled in the study. Patients were excluded if they reported a preinjection Numeric Rating Scale (NRS) score for pain with activity of <6 points out of 10. The Western Ontario and McMaster Universities Arthritis Index (WOMAC), modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), 12-Item Short Form Health Survey (SF-12), and NRS pain scores were collected before and after the procedure (6 weeks, 3 months, and 6 months). Joint space and Tönnis OA grade scores were recorded on preinjection anteroposterior pelvis radiographs.

RESULTS

A total of 18 hips from 16 patients (7 male and 9 female) (mean age, 57.6 ± 11; mean body mass index, 25.9 ± 3.6 kg/m2) were used in the final analysis. Significant improvements were observed in NRS pain with activity (from 8 to 4.5; P < .001) and without activity (from 5 to 1; P < .001), WOMAC (from 31 to 16; P = .006), mHHS (from 63 to 80; P = .004), and HOS-ADL (from 71 to 85; P = .014) over 6 months. At 6 months, all patients maintained their improvements and did not return to preprocedure status. BMI significantly correlated with baseline WOMAC scores (P = .012) and inversely correlated with 6-month SF-12 Physical Component Summary (P = .038). Tönnis grades 2 and 3 were inversely correlated with 6-week SF-12 Mental Component Summary (P = .008) and 3-month pain with activity (P = .032). No serious adverse events were reported from the BMC harvest or injection procedure.

CONCLUSION

A single BMC injection can significantly improve subjective pain and function scores up to 6 months in patients with symptomatic hip OA. Further studies are warranted to evaluate BMC treatment against other therapeutics in a larger sample size and compare the biological signature profiles that may be responsible for the therapeutic effect.

Biological strategies for osteoarthritis: from early diagnosis to treatment

PURPOSE

To provide an updated review of the literature on the use of orthobiologics as a potential treatment option to alleviate symptoms associated with osteoarthritis (OA), slow the progression of the disease, and aid in cartilage regeneration.

METHODS

A comprehensive review of the literature was performed to identify basic science and clinical studies examining the role of orthobiologics in the diagnosis and management of osteoarthritis.

RESULTS

Certain molecules (such as interleukin-6 (IL-6), interleukin-8 (IL-8), matrix metalloproteinase (MMPs), cartilage oligomeric matrix protein (COMP), and tumor necrosis factor (TNF), microRNAs, growth differentiation factor 11 (GDF-11)) have been recognized as biomarkers that are implicated in the pathogenesis and progression of degenerative joint disease (DJD). These biomarkers have been used to develop newer diagnostic applications and targeted biologic therapies for DJD. Local injection therapy with biologic agents such as platelet-rich plasma or stem cell-based preparations has been associated with significant improvement in joint pain and function in patients with OA and has increased in popularity during the last decade. The combination of PRP with kartogenin or TGF-b3 may also enhance its biologic effect. The mesenchymal stem cell secretome has been recognized as a potential target for the development of OA therapies due to its role in mediating the chondroprotective effects of these cells. Recent experiments have also suggested the modification of gut microbiome as a newer method to prevent OA or alter the progression of the disease.

CONCLUSIONS

The application of orthobiologics for the diagnosis and treatment of DJD is a rapidly evolving field that will continue to expand. The identification of OA-specific and joint-specific biomarker molecules for early diagnosis of OA would be extremely useful for the development of preventive and therapeutic protocols. Local injection therapies with HA, PRP, BMAC, and other stem cell-based preparations are currently being used to improve pain and function in patients with early OA or those with progressed disease who are not surgical candidates. Although the clinical outcomes of these therapies seem to be promising in clinical studies, future research will determine the true role of orthobiologic applications in the field of DJS.

Biologics

Biologics are a growing field that has shown immense promise for the treatment of musculoskeletal conditions both in orthopedic sports medicine and interventional pain management. These procedures utilize injection of supraphysiologic levels of platelets and growth factors to invoke the body's own inflammatory cascade to augment the healing of many bony and soft tissue conditions. While many patients improve with conservative care, there is a need to address the gap between those that improve with rehabilitation alone and those who ultimately require operative management. Orthobiologic procedures have the potential to fill this void. The purpose of this review is to summarize the basic science, evidence for use, and post-injection rehabilitation concepts of platelet-rich plasma (PRP) and mesenchymal stromal cells (MSCs) as they pertain to joints, tendons, ligaments, and the spine.

Positive early clinical outcomes of bone marrow aspirate concentrate for osteoarthritis using a novel fenestrated trocar

BACKGROUND

This study sought to assess early clinical outcomes for knee osteoarthritis (OA) patients undergoing bone marrow aspirate concentrate (BMAC) treatment using a novel closed-end, fenestrated trocar (FT) that does not require centrifugation.

METHODS

A prospective cohort of 17 knee OA patients undergoing BMAC treatment with the FT system from March 2018 to March 2019 was retrospectively evaluated. Approximately 10 mL of BMAC was harvested, no centrifugation was performed, and the BMAC was injected into the affected knee. Clinical outcomes were assessed at baseline, six weeks, and 12 weeks. This study has no affiliation with/vested-interest in the FT system.

RESULTS

There were significant improvements in nearly all outcomes from baseline to 12 weeks. Specific improvements included Knee Injury and OA Outcome Score (KOOS) activities-of-daily-living (61.1 ± 9.2 [mean ± 95% confidence interval] to 89.3 ± 6, p = 0.001), quality-of-life (32.7 ± 9.3 to 66.1 ± 17.9, p = 0.003), sports/recreation (36.9 ± 10.6 to 72.6 ± 26.3, p = 0.006), and pain (53.8 ± 9.3 to 83 ± 10.2, p = 0.001); Lysholm scores (55.5 ± 8.4 to 77.3 ± 10.5, p = 0.009); and visual analog pain scores (5.68 ± 1.14 to 2.07 ± 1.86, p = 0.003). Individually, at least 75% of patients exhibited improvement in all KOOS categories at six weeks and at least 85% at 12 weeks.

CONCLUSIONS

BMAC treatment with an FT system that does not require centrifugation resulted in significant improvements in early pain and function scores for knee OA. The symptomatic improvements in this study were similar to or greater than what has been reported using traditional needles. These data may provide clinicians with comfort in using an FT system and provide motivation for future randomized-controlled trials comparing aspiration techniques.

Autologous Mesenchymal Stem Cell Treatment is Consistently Effective for the Treatment of Knee Osteoarthritis: The Results of a Systematic Review of Treatment and Comparison to a Placebo Group

Background: Numerous studies have used autologous mesenchymal stem cell injections (AMSCI) to treat osteoarthritis. We hypothesized that AMSCI is an effective osteoarthritis treatment with increasing efficacy at higher doses. Methods: We conducted a PubMed search for human clinical studies using AMSCI for the treatment of osteoarthritis (OA) and a second search for placebo arms of injectate OA treatment. Inclusion criteria included treatment outcomes ratings both pre-treatment and at least 6 months post-treatment. Results: 45 AMSCI cohorts from 34 studies met criteria. All AMSCI cohorts showed improvement at mean 15.3 months post-treatment. Mean WOMAC and VAS scores improved at 6-months and at final follow-up (p < 0.0001 for all). Scores > 2 years were also significant (WOMAC p = 0.001/VAS p = 0.004). Results greatly exceeded the minimal clinically important difference (MCID) at each time point. AMSCI improvement also substantially exceeded previously published 6-month placebo-treatment improvement. No dose-response relationship was seen. AMSCI cohorts showed continuing improvement ≥ 6 months, and continued upward at one year. Placebo scores were already trending downward by 6 months. Conclusions: AMSCI is a consistently significantly effective treatment for osteoarthritis. It should no longer be stated that data is insufficient to establish AMSCI efficacy for OA. Given its excellent safety profile, AMSCI should be widely used for the treatment of osteoarthritis.

Cellular and Clinical Analyses of Autologous Bone Marrow Aspirate Injectate for Knee Osteoarthritis: A Pilot Study

INTRODUCTION

Knee osteoarthritis (OA) is characterized by pain and functional deficits. Common conservative strategies include medications, physical therapy, and intra-articular injections. Recently, treatment using autologous cell injections has increased.

OBJECTIVE

To characterize the cellular content of bone marrow aspirate (BMA) and to evaluate the effect of intra-articular autologous BMA injections in patients with mild knee OA.

DESIGN

Prospective pilot observational study.

SETTING

Academic institution.

PATIENTS

Eleven patients with unilateral or bilateral mild knee OA (15 knees) were included in the cellular analysis. Ten patients (13 knees) were included in the overall (cellular and clinical) analysis.

INTERVENTIONS

BMA was aspirated from patients' iliac crests and then injected intra-articularly under fluoroscopic and/or ultrasound guidance. BMA samples were analyzed using flow cytometry, colony forming unit (CFU) assays, and enzyme-linked immunosorbent assays. Questionnaires assessing pain and function were administered preinjection and at 1, 3, 6, and 12 months postinjection. Side effects and satisfaction were assessed.

MAIN OUTCOME MEASURES

Total nucleated cell (TNC) concentration, mesenchymal stem cell (MSC) concentration, CFU count, and interleukin-1 receptor antagonist (IL-1Ra) concentration.

RESULTS

BMA sample analyses revealed wide ranges in TNC concentration (173300-4 491 050 cells/mL), MSC concentration (0-500 cells/mL), CFUs (0-19), and IL-1Ra concentration (2806-29 394 pg/mL). Improvements in Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement were observed throughout the 12-month follow-up period (F[4,12] = 12.29, P < .001). Additionally, current, usual, best, and worst numerical rating scale pain scores significantly decreased over time (P < .001). Patient satisfaction was high (range: 8.1 ± 2.1-8.8 ± 1.9), and side effects were uncommon.

CONCLUSIONS

The cellular content of BMA samples varied widely between patients and was lower than the anticipated yield reported by the device's manufacturer. However, intra-articular BMA injections for knee OA in a small pilot cohort appeared to be safe with potential therapeutic value. Larger, prospective, double-blinded studies are warranted.

Mesenchymal Stromal Cell-Based Therapy-An Alternative to Arthroplasty for the Treatment of Osteoarthritis? A State of the Art Review of Clinical Trials

Osteoarthritis (OA) is the most common degenerative joint disorder worldwide and to date no regenerative treatment has been established in clinical practice. This review evaluates the current literature on the clinical translation of mesenchymal stromal cell (MSC)-based therapy in OA management with a focus on safety, outcomes and procedural specifics. PubMed, Cochrane Library and clinicaltrials.gov were searched for clinical studies using MSCs for OA treatment. 290 articles were initially identified and 42 articles of interest, including a total of 1325 patients, remained for further examination. Most of the included studies used adipose tissue-derived MSCs or bone-marrow-derived MSCs to treat patients suffering from knee OA. MSC-based therapy for knee OA appears to be safe and presumably effective in selected parameters. Yet, a direct comparison between studies was difficult due to a pronounced variance regarding methodology, assessed outcomes and evidence levels. Intensive scientific engagement is needed to identify the most effective source and dosage of MSCs for OA treatment in the future. Consent on outcome measures has to be reached and eventually patient sub-populations need to be identified that will profit most from MSC-based treatment for OA.

PAST, CURRENT AND FUTURE INTERVENTIONAL ORTHOBIOLOGICS TECHNIQUES AND HOW THEY RELATE TO REGENERATIVE REHABILITATION: A CLINICAL COMMENTARY

Interventional orthobiologics is changing the landscape of orthopedic medicine. Various methods exist for treatment of many different musculoskeletal pathologies. Candidacy for such injections remains a debated topic, and current research is underway for stratifying the patients that would be most successful for certain techniques. Described in this commentary are the various methods of interventional orthobiologic techniques available such as: prolotherapy, platelet rich plasma (PRP), mesenchymal stromal cells (MSCs), culture-expanded MSCs and amniotic-based products. Here we review the healing cascade and how this relates to the application of the various injectates and rehabilitation protocols. In conclusion, there exists orthobiologic techniques for the healing of a multitude of musculoskeletal ailments, from ligamentous instabilities/tears, tendon derangements and osteoarthritis, however candidacy grades continue to be an area for discussion as to which type of treatment is the most beneficial, and which rehabilitation protocols are required. More randomized controlled trials and comparative analyses are needed for direct correlative conclusions for which interventional orthobiologic treatment and rehabilitation protocol is best after each respective treatment.

LEVEL OF EVIDENCE

5.

Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 1 Year: A Prospective, Randomized Trial

Background:

Approximately 47 million people in the United States have been diagnosed with arthritis. Autologous platelet-rich plasma (PRP) injections have been documented to alleviate symptoms related to knee osteoarthritis (OA) in randomized controlled trials, systematic reviews, and meta-analyses. Autologous bone marrow aspirate concentrate (BMC) injections have also emerged as a treatment option for knee OA, with a limited clinical evidence base.

Purpose:

To compare the efficacy of BMC to PRP for the treatment of knee OA regarding pain and function at multiple time points up to 12 months after an injection. We hypothesized that BMC will be more effective in improving outcomes in patients with knee OA.

Study Design:

Randomized controlled trial; Level of evidence, 2

Methods:

A total of 90 participants aged between 18 and 80 years with symptomatic knee OA (Kellgren-Lawrence grades 1-3) were randomized into 2 study groups: PRP and BMC. Both groups completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and subjective International Knee Documentation Committee (IKDC) questionnaires before and 1, 3, 6, 9, and 12 months after a single intra-articular injection of leukocyte-rich PRP or BMC.

Results:

There were no statistically significant differences in baseline IKDC or WOMAC scores between the 2 groups. All IKDC and WOMAC scores for both the PRP and BMC groups significantly improved from baseline to 1 month after the injection (P < .001). These improvements were sustained for 12 months after the injection, with no difference between PRP and BMC at any time point.

Conclusion:

Both PRP and BMC were effective in improving patient-reported outcomes in patients with mild to moderate knee OA for at least 12 months; neither treatment provided a superior clinical benefit. Autologous PRP and BMC showed promising clinical potential as therapeutic agents for the treatment of OA, and while PRP has strong clinical evidence to support its efficacy, BMC has limited support. This study did not prove BMC to be superior to PRP, providing guidance to clinicians treating OA. It is possible that the results were affected by patients knowing that there was no control group.

Registration:

NCT03289416 (ClinicalTrials.gov identifier).

A Randomized Controlled Trial of the Treatment of Rotator Cuff Tears with Bone Marrow Concentrate and Platelet Products Compared to Exercise Therapy: A Midterm Analysis

Injectable regenerative therapies such as bone marrow concentrate (BMC) and platelet-rich plasma (PRP) may represent a safe alternative in the treatment of rotator cuff tears. This is a midterm review of a randomized, crossover trial comparing autologous BMC and platelet product injections versus exercise therapy in the treatment of partial and full-thickness supraspinatus tears. Patients enrolled into the study were between 18 and 65 years of age presenting to an outpatient orthopedic clinic with partial to full thickness, nonretracted supraspinatus tendon tears. Enrolled patients were randomized to either ultrasound-guided autologous BMC with PRP and platelet lysate (PL) percutaneous injection treatment or exercise therapy. Patients could cross over to BMC treatment after at least 3 months of exercise therapy. Patients completed the Disability of the Arm, Shoulder and Hand (DASH) scores as the primary outcome measure. Secondary outcomes included the numeric pain scale (NPS), a modified Single Assessment Numeric Evaluation (SANE), and a blinded MRI review. At this midterm review, results from 25 enrolled patients who have reached at least 12-month follow-up are presented. No serious adverse events were reported. Significant differences were seen in patient reported outcomes for the BMC treatment compared to exercise therapy at 3 and 6 months for pain, and for function and reported improvement (SANE) at 3 months (p < .05). Patients reported a mean 89% improvement at 24 months, with sustained functional gains and pain reduction. MRI review showed a size decrease of most tears post-BMC treatment. These findings suggest that ultrasound-guided BMC and platelet product injections are a safe and useful alternative to conservative exercise therapy of torn, nonretracted supraspinatus tendons. This trial is registered with NCT01788683.

The effect of a single consecutive volume aspiration on concentrated bone marrow from the proximal humerus for clinical application

BACKGROUND

Low aspiration volumes have been recommended to allow for higher concentrations of progenitor cells during bone marrow harvesting. However, these guidelines then require multiple aspiration attempts in order to maximize cellular yield. The purpose of this study was to investigate the effect of a single, high-volume aspiration with four consecutive aliquots on the number of nucleated cells (NCs) and colony-forming units (CFUs) in concentrated bone marrow aspirate (cBMA) taken from the proximal humerus.

METHODS

cBMA was taken from the proximal humerus of patients undergoing arthroscopic rotator cuff surgery. Four 12-mL double syringes were used consecutively from a single trocar to obtain four 10 cc aliquots. Each then underwent centrifugation to create a fractionated layer rich in nucleated cells. Following cellular separation, NCs were counted and CFUs were evaluated after incubation of 7-10 days. Cellular comparisons between each aliquot were performed along with their interaction with patient age and sex.

RESULTS

Twenty-nine patients (55.9 ± 4.6 years) were included in this study. The number of NCs and CFUs showed significant differences between the four aliquots of aspirate, with the first 10 cc aliquot providing the highest amount (p < 0.001, respectively). No significant differences were found between the sum of the three sequential aliquots compared to the initial 10 cc sample. There were no significant differences between male and female patients (p > 0.05). Increasing age resulted in no significant decrease in the number of NCs and CFUs across the four consecutive aliquots (p > 0.05).

CONCLUSION

In conclusion, while the initial aliquot provided the greatest number of nucleated cells and cultured CFUs, the addition of each sequential volume aspirate yielded similar amounts in total. This demonstrates the potential effectiveness of obtaining of higher volume aspirates from the proximal humerus during rotator cuff repair.

A Review of Commercially Available Point-of-Care Devices to Concentrate Bone Marrow for the Treatment of Osteoarthritis and Focal Cartilage Lesions

OBJECTIVE

Mesenchymal stem cells (MSCs) are a promising cell-based therapy treatment option for several orthopedic indications. Because culture expansion of MSC is time and cost intensive, a bedside concentration of bone marrow (BM) aspirate is used as an alternative. Many commercial systems are available but the available literature and knowledge regarding these systems is limited. We compared different point-of-care devices that concentrate BM (BMC) by focusing on technical features and quality parameters to help surgeons make informed decisions while selecting the appropriate device.

METHODS

We compared published data on the BMC devices of Arteriocyte, Arthrex, Celling Biosciences, EmCyte, Exactech, ISTO Tech, Harvest Tech/Terumo BCT, and Zimmer/BIOMET regarding technical features (centrifugation speed/time, input/output volume, kit components, type of aspiration syringes, filter usage) and quality parameters of their final BMC product (hematocrit, concentration of platelets and total nucleated cells, concentration of MSC and connective tissue progenitor cells).

RESULTS

The systems differ significantly in their technical features and centrifugation parameters. Only the fully automated systems use universal kits, which allow processing different volumes of BM. Only the Arthrex system allows selection of final hematocrit. There was no standardized reporting method to describe biologic potency.

CONCLUSIONS

Based on the data obtained in this review, recommending a single device is not possible because the reported data could not be compared between devices. A standardized reporting method is needed for valid comparisons. Furthermore, clinical outcomes are required to establish the true efficacy of these systems. We are conducting additional studies for more careful comparison among the devices.

Minimally Manipulated Mesenchymal Stem Cells for the Treatment of Knee Osteoarthritis: A Systematic Review of Clinical Evidence

Background

The use of laboratory-expanded mesenchymal stem cells (MSCs) is subject to several restrictions, resulting in “minimal manipulation” methods becoming the current most popular strategy to increase the use of MSCs in an orthopaedic practice. The aim of the present systematic review is to assess the clinical applications of “minimally” manipulated MSCs, either as bone marrow aspirate concentrate (BMAC) or as stromal vascular fraction (SVF), in the treatment of knee osteoarthritis (OA).

Methods

A systematic review of three databases (PubMed, ScienceDirect, and Google Scholar) was performed using the following keywords: “Knee Osteoarthritis” with “(Bone marrow aspirate) OR (bone marrow concentrate)” or with “(adipose-derived mesenchymal stem cells) OR (adipose derived stromal cells) OR (stromal vascular fraction) OR (SVF)” as either keywords or MeSH terms. The reference lists of all retrieved articles were further reviewed for identification of potentially relevant studies.

Results

Twenty-three papers were included in the final analysis (10 on BMAC and 13 on SVF). Of these, only 4 were randomized controlled trials (RCTs). Bias risk evaluation, performed using a modified Coleman score, revealed an overall poor quality of the studies. In terms of clinical application, despite the apparent safety of minimally manipulated MSCs and the short-term positive clinical outcomes associated with their use, clinicians reported different preparation and administration methods, ranging from single intra-articular injections to intraosseous applications to administration in combination with other surgical procedures.

Conclusions

The available literature is undermined by both the lack of high-quality studies and the varied clinical settings and different protocols reported in the few RCTs presently published. This prevents any recommendation on the use of either product in a clinical practice. Nevertheless, the use of minimally manipulated MSCs (in the form of BMAC or SVF) has been shown to be safe and have some short-term beneficial effects.

Intra-articularly injected mesenchymal stem cells promote cartilage regeneration, but do not permanently engraft in distant organs

Intra-articular (IA) injection of mesenchymal stem cells (MSCs) promotes articular cartilage repair. However, cell fate and action after transplantation remain unclear. This study aimed at evaluating the biodistribution and efficacy of MSCs after IA injection. We used an immunocompetent, dual transgenic rat model, which is based on donor rats ubiquitously expressing heat stable human placental alkaline phosphatase (ALPP), and recipient rats expressing a heat sensitive ALPP form. A focal cartilage defect was created in the patellofemoral groove of recipient rats. Bone marrow-derived MSCs isolated from donor rats were injected into the synovial cavity of recipients, and cell tracking was performed in distant organs and knees over 6 months post-injection. A few donor MSCs were observed in the lung of one of the recipients, 1 day post-injection. We failed to detect donor MSCs in any of the studied tissues at all later time points. IA-injected MSCs remained in the synovial cavity, engrafted within the cartilage lesion, and were detectable up to 1 month post-injection. Although the number of MSCs decreased over time, MSCs injection promoted cartilage regeneration as evidenced by histology and immunofluorescent collagen staining. Our study supports the safety and efficacy of using MSCs for cartilage repair via IA delivery.

Injective mesenchymal stem cell-based treatments for knee osteoarthritis: from mechanisms of action to current clinical evidences

PURPOSE

Osteoarthritis (OA) represents a relevant social and economic burden worldwide. "Mesenchymal stem cells" or, as recently proposed, "medicinal signaling cells" (MSCs) have been recently introduced as injective treatments for OA with the aim of restoring joint homeostasis. The aim of this review is to provide the reader with the tools necessary to interpret the currently available clinical data, focusing on the MSC mechanisms of action which might help to clarify what we should expect from this treatment.

METHODS

Clinical studies reporting MSC injections for the treatment of knee OA, either freshly isolated or culture-expanded cells, have been included and commented in relation to the supposed therapeutic effect that MSCs might exert giving their supposed mode of actions.

RESULTS

The majority of the studies reports significant improvements in terms of pain and knee function compared to baseline values, up to 24 months of follow-up. Although these data support the expected therapeutic effect of this therapy giving the features of these cells, only 14% of the studies present a control group and more than one-third of them report the results on less than ten patients.

CONCLUSIONS

Despite the constant presence of positive and satisfactory results in the studies analyzed, the complexity of MSC metabolism and related therapeutic effects as well as the weakness of most of the studies do not allow withdrawing definitive conclusions about the superiority of one tissue source over another, as well as about the best cell dose and the long-term durability of the effects of these procedures. Given the high potential value of these therapies in the treatment of OA, further studies accurately designed, carefully defining the type of patients to be included and pursuing minimal standard requirements in terms of follow-up, number of patients, and types of measurements should be conducted to finally assess the efficacy of MSC-based injective treatments.

Quality assurance and adverse event management in regenerative medicine for knee osteoarthritis: Current concepts

The economic and human cost of knee osteoarthritis is forecast to increase. This will impact not only aging individuals, but also the working age members of emerging economies. The current treatment pathways are often costly, time-consuming, and insufficient to manage the degeneration of the knee over the ever-increasing lifespan of patients around the world. In response to the shortcomings of a focus on symptom management, international and high-impact regulators, researchers, clinicians, and most importantly patients, are increasingly interested in the possible management of knee osteoarthritis with novel therapies in the field of regenerative medicine treatments. Regenerative medicine is an emerging discipline whose adherents aim to use the tools of the human body to address underlying dysfunction, leading to lasting repair of damaged tissues and structures. The evidence base lacks consensus on issues related to safety, efficacy, cost-efficiency, and treatment specifications. In this current concepts review, we describe the potential impact of regenerative medicine for knee osteoarthritis and evaluate literature of the past decade for elements related to the quality of clinical research. Finally, we discuss strategies for improving the evidence base for the future. The results of the review reveal that the typical follow-up period for most clinical research into the area is between 6 and 12 months; local ethics board approval is commonly reported, and that Platelet-Rich Plasma is the most common option explored. However, several quality elements were lacking in this cohort of recent literature: cost efficacy data, long-term follow-up, and detailed adverse event reporting. In order to address these weaknesses in the literature, patient outcomes registries are needed, in order to satisfy the need for longer follow-up for individuals receiving regenerative treatments, in addition to further clinical trials which address larger and more diverse patient populations. Transparency will be of utmost importance in further research and clinical translation of regenerative medicine for knee osteoarthritis.

A specific protocol of autologous bone marrow concentrate and platelet products versus exercise therapy for symptomatic knee osteoarthritis: a randomized controlled trial with 2 year follow-up

Background

Cell-based therapies have shown promise for the treatment of knee osteoarthritis (OA). The current study compared exercise therapy to autologous bone marrow concentrate (BMC) and platelet products for knee OA treatment.

Methods

Patients with symptomatic knee OA (N = 48) were randomized into either an exercise therapy control group or treatment group with injection of autologous BMC and platelet products. Patients in the control group could crossover to BMC treatment after 3 months. Clinical outcomes were documented at baseline and at 6-weeks, 3, 6, 12 and 24 months, including the Knee Society Score (KSS), Pain Visual Analogue Scale, Short Form-12 Scales (SF-12), and Lower Extremity Activity Scale (LEAS).

Results

All patients in the exercise group crossed over to receive BMC treatment after 3 months (N = 22 crossover). At 3 months, KSS-knee, SF-12 Physical, and LEAS improved significantly in the crossover group compared to exercise, similar to significant improvements on KSS-knee and LEAS for the treatment group (N = 26) compared to exercise group at 3 months. After BMC treatment, patients’ clinical outcome scores (except SF-12 Mental Health), were significantly improved through the 2-year follow-up compared to baseline. No serious adverse events were reported.

Conclusion

The use of image-guided percutaneous BMC with platelet products yielded better results than exercise therapy as an effective alternative therapy for patients with symptomatic moderate to moderate-severe osteoarthritis of the knee.

Trial registration NCT02034032. https://clinicaltrials.gov/ct2/show/NCT02034032. Registered 13 January 2014