Reporting Standards in Clinical Studies Evaluating Bone Marrow Aspirate Concentrate: A Systematic Review

Arthroscopy With Adipose-Derived Stromal Vascular Fraction Using a Selective Tissue Engineering Photo-Stimulation Technique for the Treatment of Mild to Moderate Knee Osteoarthritis

Osteoarthritis (OA) is characterized by articular cartilage degeneration, synovial inflammation, and subchondral bone thickening, affecting the synovial joint as an organ and leading to pain and disability. Subcutaneous stromal vascular fraction is safe and relieves pain, improves function, and repairs cartilage defects in patients with knee OA. Our goal is to describe step-by-step the arthroscopic treatment of mild to moderate knee OA with photo-stimulated stromal vascular fraction harvested from the thigh using a selective tissue engineering photo-stimulation ("One S.T.E.P.") technique.

Profound Properties of Protein-Rich, Platelet-Rich Plasma Matrices as Novel, Multi-Purpose Biological Platforms in Tissue Repair, Regeneration, and Wound Healing

Autologous platelet-rich plasma (PRP) preparations are prepared at the point of care. Centrifugation cellular density separation sequesters a fresh unit of blood into three main fractions: a platelet-poor plasma (PPP) fraction, a stratum rich in platelets (platelet concentrate), and variable leukocyte bioformulation and erythrocyte fractions. The employment of autologous platelet concentrates facilitates the biological potential to accelerate and support numerous cellular activities that can lead to tissue repair, tissue regeneration, wound healing, and, ultimately, functional and structural repair. Normally, after PRP preparation, the PPP fraction is discarded. One of the less well-known but equally important features of PPP is that particular growth factors (GFs) are not abundantly present in PRP, as they reside outside of the platelet alpha granules. Precisely, insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) are mainly present in the PPP fraction. In addition to their roles as angiogenesis activators, these plasma-based GFs are also known to inhibit inflammation and fibrosis, and they promote keratinocyte migration and support tissue repair and wound healing. Additionally, PPP is known for the presence of exosomes and other macrovesicles, exerting cell-cell communication and cell signaling. Newly developed ultrafiltration technologies incorporate PPP processing methods by eliminating, in a fast and efficient manner, plasma water, cytokines, molecules, and plasma proteins with a molecular mass (weight) less than the pore size of the fibers. Consequently, a viable and viscous protein concentrate of functional total proteins, like fibrinogen, albumin, and alpha-2-macroglobulin is created. Consolidating a small volume of high platelet concentrate with a small volume of highly concentrated protein-rich PPP creates a protein-rich, platelet-rich plasma (PR-PRP) biological preparation. After the activation of proteins, mainly fibrinogen, the PR-PRP matrix retains and facilitates interactions between invading resident cells, like macrophages, fibroblast, and mesenchymal stem cells (MSCs), as well as the embedded concentrated PRP cells and molecules. The administered PR-PRP biologic will ultimately undergo fibrinolysis, leading to a sustained release of concentrated cells and molecules that have been retained in the PR-PRP matrix until the matrix is dissolved. We will discuss the unique biological and tissue reparative and regenerative properties of the PR-PRP matrix.

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.

Bone Marrow Aspirate Concentrate Improves Outcomes in Adults With Osteochondral Dissecans of the Talus and Achilles Rupture

PURPOSE

The objective of this systematic literature review was to investigate the effects of the clinical application of bone marrow aspirate (BMA) and/or bone marrow aspirate concentrate (BMAC) in tendon and cartilage injuries in the foot and ankle.

METHODS

A search of the Embase, MEDLINE/PubMed, CINAHL, and Cochrane databases was performed in January 2021. The risk of bias of the studies was assessed using the tool "A Cochrane Risk of Bias Assessment Tool for Non-Randomized Studies." The outcomes analyzed included pain reduction and functional improvement with the use of BMA/BMAC in patients with tendon and cartilage injuries in the foot and ankle.

RESULTS

Eleven studies met the inclusion criteria for analysis, involving a total of 527 subjects with osteochondral lesions (OCLs) of the talus, cartilage lesions of the talus, and acute Achilles tendon rupture. BMAC was applied alone in 4 studies, and in 7 studies, it was compared with other techniques such as matrix-induced autologous chondrocyte implantation, particulate juvenile articular cartilage, or microfracture. Interventions demonstrated improved function and reduced foot and ankle pain and showed no serious adverse effects.

CONCLUSIONS

Evidence indicates that BMAC provides good clinical results, with improved function and reduced pain in adults with OCL and cartilage lesions of the talus and acute Achilles tendon rupture.

LEVEL OF EVIDENCE

Level IV, systematic review of level II to IV studies.

Regulatory and Ethical Aspects of Orthobiologic Therapies

Orthobiologic therapies show significant promise to improve outcomes for patients with musculoskeletal pathology. There are considerable research efforts to develop strategies that seek to modulate the biological environment to promote tissue regeneration and healing and/or provide symptomatic relief. However, the regulatory pathways overseeing the clinical translation of these therapies are complex, with considerable worldwide variation. The introduction of novel biologic treatments into clinical practice raises several ethical dilemmas. In this review, we describe the process for seeking approval for biologic therapies in the United States, Europe, and Japan. We highlight a number of ethical issues raised by the clinical translation of these treatments, including the design of clinical trials, monitoring outcomes, biobanking, "off-label" use, engagement with the public, marketing of unproven therapies, and scientific integrity.

Current Trends in Orthobiologics: An 11-Year Review of the Orthopaedic Literature

BACKGROUND

The use of "orthobiologics" or regenerative therapies in orthopaedic surgery has grown in recent years. Particular interest has been raised with regard to platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells. Although studies have analyzed outcomes after orthobiologic treatment, no study has analyzed how the literature as a whole has evolved.

PURPOSE

To evaluate trends in platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cell publications and to assess how these might inform efforts to establish minimum reporting standards and forecast future use.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A database was compiled systematically using PubMed to identify articles published between 2009 and 2019 within 9 prominent orthopaedic journals and pertaining to the use of platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells in the treatment of musculoskeletal conditions. Included articles were classified as clinical, nonclinical (translational or basic science), or review, and a variety of study parameters were recorded for each. Additional queries were performed to identify articles that utilized minimum reporting standards.

RESULTS

A total of 474 articles (132 clinical, 271 nonclinical, 71 review) were included, consisting of 244 (51.5%) platelet-rich plasma, 146 (30.8%) bone marrow aspirate, 72 (15.2%) adipose-derived cells, and 12 (2.5%) amniotic cells. The greatest annual increase in publications for each orthobiologic topic was from 2018 to 2019. The American Journal of Sports Medicine demonstrated the highest number of overall (34.2%) and clinical (50.0%) publications, and accounted for 44.3% of all platelet-rich plasma publications. The Journal of Orthopaedic Research accounted for the second highest overall number of publications (24.9%) and highest nonclinical publications (41.0%). Platelet-rich plasma accounted for 91.5% of all level 1 clinical studies, while much greater than half of bone marrow aspirate, adipose-derived cells, and amniotic cell publications were level 3 or lower. Out of the 207 articles that used some form of reporting protocol, 59 (28.5%) used an established algorithm and 125 (60.4%) used their own.

CONCLUSION

Interest in orthobiologics continues to grow, as evidenced by an increasing trend in publications over an 11-year period. However, current reporting on orthobiologic formulations is largely heterogeneous, emphasizing the need for minimum reporting standards and higher-quality studies.

Clinical Outcomes After Arthroscopic Rotator Cuff Repair With a Fibrin Scaffold Containing Growth Factors and Autologous Progenitor Cells Derived from cBMA

Purpose

To report the clinical outcomes after biologically augmented rotator cuff repair (RCR) with a fibrin scaffold derived from autologous whole blood and supplemented with concentrated bone marrow aspirate (cBMA) harvested at the proximal humerus.

Methods

Patients who underwent arthroscopic RCR with biologic augmentation using a fibrin clot scaffold (“Mega- Clot”) containing progenitor cells and growth factors from proximal humerus BMA and autologous whole blood between April 2015 and January 2018 were prospectively followed. Only high-risk patients in primary and revision cases that possessed relevant comorbidities or physically demanding occupation were included. Minimum follow-up for inclusion was 1 year. The visual analog score for pain (VAS), American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test (SST), Single Assessment Numerical Evaluation (SANE), and Constant-Murley scores were collected preoperatively and at final follow-up. In vitro analyses of the cBMA and fibrin clot using nucleated cell count, colony forming units, and live/dead assays were used to quantify the substrates.

Results

Thirteen patients (56.9 ± 7.7 years) were included. The mean follow-up was 26.9 ± 17.7 months (n = 13). There were significant improvements in all outcome scores from the preoperative to the postoperative state: VAS (5.6 ± 2.5 to 3.1 ± 3.2; P < .001), ASES (42.0 ± 17.1 to 65.5 ± 30.6; P < .001), SST (3.2 ± 2.8 to 6.5 ± 4.7; P = .002), SANE (11.5 ± 15.6 to 50.3 ± 36.5; P < .001), and Constant-Murley (38.9 ± 17.5 to 58.1 ± 26.3; P < .001). Six patients (46%) had retears on postoperative MRI, despite all having improvements in pain and function except one. All failures were chronic rotator cuff tears, and all were revision cases except one (1.6 ± 0.5 previous RCRs). The representative sample of harvested cBMA showed an average of 28.5 ± 9.1 × 10⁶ nucleated cells per mL.

Conclusions

Arthroscopic rotator cuff repairs that are biologically augmented with a fibrin scaffold containing growth factors and autologous progenitor cells derived from autologous whole blood and humeral cBMA can improve clinical outcomes in primary, as well as revision cases in high-risk patients. However, the incidence of retears remains a concern in this population, demanding further improvements in biologic augmentation.

Level of Evidence

IV, therapeutic case series.

Reorientation technique has benefits in bone marrow aspiration of stem cells

We treated patients with osteoarthritis of the knee using injections of bone marrow aspirate concentrate (stem cell therapy). Since multiple controversial harvesting methods using different sites, needles, volumes and techniques have been described, we aimed to compare those methods. Four different harvesting sites at the iliac crest, three different types of needles, three different types of volumes and two different harvesting techniques were compared in 48 bone marrow aspirations. The conventional technique (Group 1) was compared with a reorientation technique (Group 2). The number of leucocytes and CD34 + cells and the viability in bone marrow aspirate (BMA) were analysed with a CytoFLEX Flow Cytometer. The reorientation technique showed significantly higher cell counts than the conventional technique in all parameters. Leucocytes per nl increased from 5 ± 2 to 12 ± 4 (p < .001), and CD 34 + cells per μl increased from 40 ± 40 to 140 ± 98 (p = .003). There was no difference between anterior and posterior harvesting at the iliac crest or between use of a thick and use of a thin needle. Use of the reorientation technique, compared to employing the conventional technique, has a significant advantage since the number of leucocytes and CD34 + cells can be tripled. For the use of bone marrow aspirate in the case of arthritis, it might therefore be a future option to harvest a maximum cell yield through the new reorientation technique and to omit centrifugation. However, the clinical relevance of these findings remains the subject of future studies.

Level of Evidence: Level I.

Clinical relevance: Enhanced technique of BMA for knee surgeons to ensure the maximum cell yield for stem cell therapy in regenerative medicine.

Orthobiologics for the Management of Early Arthritis in the Middle-Aged Athlete

This article is dedicated to the use of orthobiologic therapies in the management of early osteoarthritis in middle-aged athletes. Understanding a patient's presenting symptoms, physical examination, imaging results, and goals is of critical importance in applying orthobiologic therapies. The field of orthobiologics is expanding at a rapid pace, and the clinical studies examining the utility of each treatment lag behind the direct-to-consumer marketing that leads to these products being used. Here we provide a review of the available treatments, emerging treatments, and the current literature supporting or refuting their use. Currently studied orthobiologics include autologous and allogenic cell therapies, autologous blood products, hyaluronic acid, gene therapies, Wnt inhibitors, and a variety of systemic treatments.

Core decompression combined with intralesional autologous bone marrow derived cell therapies for osteonecrosis of the femoral head in adults: A systematic review and meta-analysis

BACKGROUND

Core decompression (CD) is beneficial in the early stage of osteonecrosis of the femoral head (ONFH). Adjunctive bone marrow derived cell therapies (BMDCT) have been advocated which potentially aid the regenerative process.

QUESTION/PURPOSE

This study was conducted to determine potential benefit of CD + BMDCT in ONFH, in terms of disease progression, conversion to arthroplasty (primary outcomes), and functional outcomes and complication rates (secondary outcomes).

METHODS

A systematic review of literature was performed on 3 databases. Studies reporting CD + BMDCT (intralesional instillation) in ONFH, with a minimum follow up of 1 year and reporting the pre-defined outcome measures were included in the review. Meta-analysis consisted of two different arms: a comparative arm, to compare CD + BMDCT to CD alone, and a non-comparative meta-analysis arm, to determine pooled rates of disease progression, conversion to arthroplasty and complication rates.

RESULTS

A total of 18 studies were included in the systematic review. CD + BMDCT had lower rates of disease progression (OR 0.19 [95% CI, 0.09, 0.40]) and conversion to arthroplasty (OR 0.20 [95% CI, 0.11, 0.40]) as compared to CD alone. Functional score (MD = -7.07 [95% CI, -12.28, -1.86]) and visual analog scale also showed better improvement with the use of CD + BMAC (MD = -10.39 [95% CI, -12.87, -7.90]). Increasing age and post-collapse stage at presentation were noted to have an adverse effect on the outcomes.

CONCLUSION

CD + BMDCT was found to decrease disease progression and conversion to arthroplasty, and was noted to have better functional outcome scores as compared to CD alone.

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.

Systematic Review of Platelet-Rich Plasma for Rotator Cuff Repair: Are We Adhering to the Minimum Information for Studies Evaluating Biologics in Orthopaedics?

Background

The therapeutic efficacy of orthobiologic therapies for rotator cuff repair is difficult to evaluate owing to reporting inconsistences. In response, the Minimum Information for Studies Evaluating Biologics in Orthopaedics (MIBO) guidelines were developed to ensure standard reporting on orthobiologic therapies.

Purpose

To systematically review clinical studies evaluating platelet-rich plasma (PRP) for full-thickness rotator cuff repair and adherence to MIBO guidelines.

Study Design

Scoping review; Level of evidence, 4.

Methods

A search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using PubMed, EMBASE, and the Cochrane Library databases. Inclusion criteria were clinical studies reporting on rotator cuff tears (≥1 cm) surgically repaired with PRP. Patient demographics, biologic intervention, and adherence to the MIBO guidelines were systematically reviewed.

Results

A total of 19 studies (1005 patients) were included in this review. Across all studies, 58.5% of the MIBO checklist items for PRP were reported. Out of 47 checklist items, 19 were reported in over 85% of studies, whereas 22 were reported in less than half of studies. Details of whole-blood processing and characteristics, as well as PRP processing and characteristics, were reported inconsistently, and no study provided adequate information to enable the precise replication of preparation protocols for PRP.

Conclusion

This systematic review highlights the current reporting deficiencies within the scientific literature of important variables for evaluating PRP for full-thickness rotator cuff repair. There was widespread variability among published studies that evaluate PRP for this application and, more specifically, studies were limited by inconsistent universal reporting of whole-blood and PRP processing and postprocessing characteristics. To improve our understanding of biologic efficacy and to promote repeatability, stricter adherence to the MIBO guidelines is necessary. We propose that the checklist limitations be addressed and that modification of the MIBO guidelines be considered to improve the reporting of individual components within certain categories.

Injection of Bone Marrow Aspirate for Glenohumeral Joint Osteoarthritis: A Pilot Randomized Control Trial

Purpose

To compare the efficacy of a single, intra-articular, nonconcentrated bone marrow aspirate (BMA) injection in comparison to cortisone for the treatment of glenohumeral joint osteoarthritis (GHJ OA).

Methods

Inclusion criteria were patients between the ages of 18 and 75 with a diagnosis of GHJ OA on radiograph. Patients were randomized to receive an ultrasound-guided, intra-articular cortisone injection or BMA injection (without concentration). The primary outcome measure was the Western Ontario Osteoarthritis of the Shoulder (WOOS) index at 12 months. Secondary outcome measures were the QuickDASH, EuroQOL 5-dimensions 5-level questionnaire (EQ-5D-5L) and visual analogue scale.

Results

The study included 25 shoulders of 22 patients who completed baseline and 12 months’ patient-reported outcome measures (12 shoulders received cortisone, 13 shoulders received BMA) after the study was terminated early by changes in Health Canada regulations. Baseline characteristics demonstrated a significant difference in the ages of the 2 groups, with the BMA group being older (61.6 vs 53.8 mean years, P = 0.021). For the BMA group, a significant improvement was seen in the WOOS index (P = 0.002), the QuickDASH (P < 0.001), and the EQ-5D-5L pain dimension (P = 0.004) between baseline and 12 months. No significant difference was seen for any outcome in the cortisone group between baseline and 12 months. No significant difference was demonstrated between changes in the WOOS scores from baseline to 12 months when compared between groups (P = 0.07). However, a significant difference in changes in scores was seen in the QuickDASH (P = 0.006) and the EQ-5D-5L pain scores (P = 0.003) and the EQ-5D-5L health scores (P = 0.032) in favor of BMA.

Conclusions

The results of this study demonstrate that patients with GHJ OA treated with BMA have superior changes in the QuickDASH and EQ-5D-5L pain and health scores but not in the WOOS outcomes measures at 12 months post injection when compared to patients treated with cortisone. However, because of the limited number of patients as a result of the early termination of the study, larger randomized studies are required to confirm these findings.

Level of Evidence

Level II, randomized controlled trial.

Characterization of wild-type and STAT3 signaling-suppressed mesenchymal stem cells obtained from hemovac blood concentrates

Background

Venous blood drained from the knee joint after total knee arthroplasty (TKA) using a hemovac line is a potential source of bone marrow components, including stem cells, from the cutting surface of cancellous bones of the knee joint. However, the function of mesenchymal stem cells (MSCs) in patients with osteoarthritis (OA-MSCs) can be disrupted by inflammation of the joint. Further, to override the invasive nature of the currently used methods to obtain stem cells, their functional modification is necessary for therapeutic applications.

Methods

The effects of signal transducer and activator of transcription 3 (STAT3) signaling suppression on MSCs (iSTAT3-MSCs) were evaluated by comparative analyses of the characteristics of OA-MSCs and iSTAT3-MSCs from 20 patients who underwent TKA.

Results

OA-MSCs and iSTAT3-MSCs were adherent, with fibroblast-like appearance and high rates of expression of MSC-specific markers, including CD73, CD90, and CD105 (>90%). Both OA-MSCs and iSTAT3-MSCs were able to differentiate into osteogenic, adipogenic, and chondrogenic cells; however, iSTAT3-MSCs showed higher levels of osteogenic and chondrogenic differentiation markers than OA-MSCs. Additionally, the anti-inflammatory and chondroprotective cytokine levels were higher in iSTAT3-MSCs than in OA-MSCs.

Conclusions

These findings indicate that iSTAT3-MSCs after TKA are potentially effective for stem cell therapy in the context of bone and cartilage disorders.

Strategies to Identify Mesenchymal Stromal Cells in Minimally Manipulated Human Bone Marrow Aspirate Concentrate Lack Consensus

BACKGROUND

There is a need to identify and quantify mesenchymal stromal cells (MSCs) in human bone marrow aspirate concentrate (BMAC) source tissues, but current methods to do so were established in cultured cell populations. Given that surface marker and gene expression change in cultured cells, it is doubtful that these strategies are valid to quantify MSCs in fresh BMAC.

PURPOSE

To establish the presence, quantity, and heterogeneity of BMAC-derived MSCs in minimally manipulated BMAC using currently available strategies.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Five published strategies to identify MSCs were compared for suitability and efficiency to quantify clinical-grade BMAC-MSCs and cultured MSCs at the single cell transcriptome level on BMAC samples being used clinically from 15 orthopaedic patients and on 1 cultured MSC sample. Strategies included (1) the guidelines by the International Society for Cellular Therapy (ISCT), (2) CD271 expression, (3) the Ghazanfari et al transcriptional profile, (4) the Jia et al transcriptional profile, and (5) the Silva et al transcriptional profile.

RESULTS

ISCT guidelines did not identify any MSCs in BMAC at the transcriptional level and only 1 in 9 million cells at the protein level. Of 12,850 BMAC cells, 9 expressed the CD271 gene. Only 116 of 396 Ghazanfari genes were detected in BMAC, whereas no cells expressed all of them. No cells expressed all Jia genes, but 25 cells expressed at least 13 of 22. No cells expressed all Silva genes, but 19 cells expressed at least 8 of 23. Most importantly, the liberalized strategies tended to identify different cells and most of them clustered with immune cells.

CONCLUSION

Currently available methods need to be liberalized to identify any MSCs in fresh human BMAC and lack consensus at the single cell transcriptome and protein expression levels. These different cells should be isolated and challenged to establish phenotypic differences.

CLINICAL RELEVANCE

This study demonstrated that improved strategies to quantify MSC concentrations in BMAC for clinical applications are urgently needed. Until then, injected minimally manipulated MSC doses should be reported as rough estimates or as unknown.

The Radiographic Effect of Bone Marrow Aspirate Concentrate on Bone Maturation During Mandibular Distraction Osteogenesis (A Randomized Clinical Trial)

BACKGROUND

This study aims to evaluate the effect of bone marrow aspirate concentrate (BMAC) during distraction on the consolidation period.

METHODS

The study had 2 groups each had 6 patients. In the control, the distraction had no enhancement; while, the study group was enhanced by BMAC. The bone quality and quantity were assessed using cone beam computed tomography (CBCT).

RESULTS

The assessment of bone density showed non-significant (NS) (P = 0.06) increase in bone density in the study group (M = 293 ± 100 HU) compared to the control group (M = 176 ± 94 HU). The Assessment of bone volume showed a NS (P = 0.15) increase in bone volume in Study group with average bone volume/total volume (M = 49.47% ± 4.5%) compared to Control group (M = 43.9% ± 7.5%).

CONCLUSION

Further examination is recommended to evaluate the effect of BMAC on the distracted bone. The addition of BMAC made a non-significant improvement in bone quantity and quality.

Analysis of Time to Form Colony Units for Connective Tissue Progenitor Cells (Stem Cells) Harvested From Concentrated Bone Marrow Aspirate and Subacromial Bursa Tissue in Patients Undergoing Rotator Cuff Repair

Purpose

To evaluate the time required for colonies to develop from concentrated bone marrow aspirate (cBMA) and subacromial bursal tissue samples.

Methods

Samples of cBMA and subacromial bursa tissue were harvested from patients undergoing rotator cuff repair surgery between November 2014 and December 2019. Samples were analyzed for time to form colonies and number of colonies formed. The impact of age, sex, and cellularity (cBMA only) was analyzed. Samples were cultured and evaluated daily for colony formation in accordance with the guidelines of the International Society for Cellular Therapy. Demographic factors were analyzed for impact on time to form colonies and number of colonies formed.

Results

Samples of cBMA were obtained from 92 patients. Subacromial bursa tissue was obtained from 54 patients. For cBMA, older age was associated with more days to form colonies (P = .003), but sex (P = .955) and cellularity (P = .623) were not. For bursa, increased age was associated with longer time to form colonies (P = .002) but not sex (P = .804). Conclusions: Increased age (in cBMA and subacromial bursa tissue) and lower initial cellularity (in cBMA) are associated with longer time to form colonies in culture.

Clinical Relevance

Although connective tissue progenitor cells are widely used in orthopaedic practice, there are few metrics to determine their efficacy. Time to form colonies may serve as an important measurement for determining connective tissue progenitor cell viability for augmentation of rotator cuff repair. Subacromial bursa tissue may represent a viable alternative to cBMA for augmentation of rotator cuff repair, capable of forming colonies expediently in vivo.

Proximal Humerus and Ilium Are Reliable Sources of Bone Marrow Aspirates for Biologic Augmentation During Arthroscopic Surgery

PURPOSE

The purpose of this study was to evaluate the number of colony-forming units (CFUs) derived from concentrated bone marrow aspirates (BMAs) that were processed following arthroscopic harvest from either the proximal humerus or the body of the ilium during biologic augmentation of the rotator cuff and acetabular labral repairs.

METHODS

Between November 2014 and January 2019, BMA was harvested from the proximal humerus (n = 89) and the body of the ilium (n = 30) during arthroscopic surgery. Following concentration of the aspirate, a 0.5-mL aliquot was further processed and the number of nucleated cells (NC) was counted. Each aliquot was cultured until CFUs were quantifiable. Fluorescence-activated cell sorting analysis and quantitative polymerase chain reaction was performed to confirm presence of mesenchymal stem cells. BMA harvest sites were prospectively assessed and evaluated for differences in age, sex, volume of aspirated BM, and CFUs per milliliter of BMA.

RESULTS

The prevalence (38.57 ± 27.92_ilium vs. 56.00 ± 25.60_humerus CFUs per 10⁶ nucleated cells) and concentration (979.17 ± 740.31_ilium vs. 1,516.62 ± 763.63_humerus CFUs per 1.0 mL BMA) of CFUs was significantly higher (P < .001, respectively) for BMA harvested from the proximal humerus. Additionally, the estimated total number of cells was significantly higher (P = .013) in BMA from the proximal humerus (97,529.00 ± 91,064.01_ilium vs. 130,552.4 ± 85,294.2_humerus). There was no significant difference between groups regarding BMA volume (91.67 ± 18.77_ilium vs. 85.63 ± 35.61_humerus mL; P = .286) and NC count (24.01 ± 5.13_ilium vs. 27.07 ± 6.28_humerus × 10⁶ per mL BMA; P = .061). The mean age was significantly lower (P < .001) in patients with BMA being harvested from the ilium (30.18 ± 7.63_ilium vs. 56.82 ± 7.08_humerus years). Patient sex and age had no significant influence on cellular measures within groups (P > .05, respectively).

CONCLUSION

Both proximal humerus and the body of the ilium can be considered reliable sources of bone marrow aspirate for the use in biologic augmentation during their respective arthroscopic surgery. Samples of bone marrow aspirate from the proximal humerus yielded a significantly higher amount of CFUs when compared with samples of BMA obtained from the ilium.

LEVEL OF EVIDENCE

Level II- prospective laboratorial study.

Orthobiologics in Elbow Injuries

Orthobiologics are exciting tools providing promising results for difficult orthopedic conditions. In the elbow there is high-level evidence for their use in lateral epicondylopathy and encouraging evidence for other elbow pathologies. This article provides an in-depth review of the current literature for the use of orthobiologics in elbow injuries.

A Practical Guide for the Current Use of Biologic Therapies in Sports Medicine

Over the past decade, there has been an increased interest in the use of biologic therapies in sports medicine. Although these technologies are in relatively early stages of development, there have been substantial increases in marketing, patient demand, and clinical utilization of biologics, including platelet-rich plasma, bone marrow aspirate concentrate, and other cell-derived therapies. Direct-to-consumer marketing of biologics has also proliferated but is largely unregulated, and clinicians must accurately convey the safety and efficacy profiles of these therapies to patients. Because most insurance companies consider biologic treatments to be experimental or investigational for orthopaedic applications given the lack of high-quality evidence to support their efficacy, patients receiving these treatments often make substantial out-of-pocket payments. With a range of treatment costs among centers offering biologics, there is a need for appropriate and sustainable pricing and reimbursement models. Clinicians utilizing biologics must also have a thorough understanding of the recently clarified Food and Drug Administration guidelines that regulate the clinical use of cell and tissue products. There is a lack of consensus on the optimal preparation, source, delivery method, and dosing of biologic therapies, which has been exacerbated by a lack of sufficient experimental detail in most published studies. Future research must better identify the biologic target of treatment, adhere to better standards of reporting, and better integrate researchers, industry, and regulatory bodies to optimize applications.

Use of Biologics as an Adjunct Therapy to Arthroscopic Surgery for the Treatment of Femoroacetabular Impingement: A Systematic Review

BACKGROUND

There has been a recent increase in the use of biologics in hip arthroscopy to assist in the management of femoroacetabular impingement (FAI).

PURPOSE

To analyze the current use of biologics for the treatment of FAI and its associated lesions.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A search of the PubMed, Medline, and EMBASE databases was performed in March 2019 with use of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The criterion for inclusion was observational, published research articles studying the therapeutic use of biologics as an adjuvant therapy during arthroscopic surgery for FAI; treatments included bone marrow aspirate concentrate, mesenchymal stem cells (MSCs), platelet-rich plasma (PRP), hyaluronic acid, growth factors, and autologous chondrocyte implantation (ACI) or autologous matrix-induced chondrogenesis (AMIC).

RESULTS

There were 9 studies that met the inclusion criteria, and a total of 674 patients were included across all studies. FAI was studied in all articles. Further, 7 studies (78%) also analyzed chondral injuries, and 3 studies also analyzed labral tears (33%). ACI or AMIC was used in 56% of studies and showed superior functional outcomes at short- and midterm follow-up versus debridement or microfracture. PRP did not improve the outcome of labral repairs at short-term follow-up.

CONCLUSION

The current literature regarding biologic adjuncts in hip arthroscopy is varied in quality, with only one level 1 study. The use of ACI/AMIC for medium-sized chondral lesions showed promising results in individual studies; however, these were of lower quality. To enable comparisons among future studies, investigators must ensure accuracy in the reporting of biologic preparations and formulations used and homogeneity in the type and severity of lesion treated.

Characterization of Growth Factors, Cytokines, and Chemokines in Bone Marrow Concentrate and Platelet-Rich Plasma: A Prospective Analysis

BACKGROUND

Platelet-rich plasma (PRP) and bone marrow concentrate (BMC) are orthobiologic therapies with numerous growth factors and other bioactive molecules. Before the clinical utility of PRP and BMC is optimized as a combined therapy or monotherapy, an improved understanding of the components and respective concentrations is necessary.

PURPOSE

To prospectively measure and compare anabolic, anti-inflammatory, and proinflammatory growth factors, cytokines, and chemokines in bone marrow aspirate (BMA), BMC, whole blood, leukocyte-poor PRP (LP-PRP), and leukocyte-rich PRP (LR-PRP) from samples collected and processed concurrently on the same day from patients presenting for elective knee surgery.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Patients presenting for elective knee surgery were prospectively enrolled over a 3-week period. Whole blood from peripheral venous draw and BMA from the posterior iliac crest were immediately processed via centrifugation and manual extraction methods to prepare LR-PRP, LP-PRP, and BMC samples, respectively. BMA, BMC, whole blood, LR-PRP, and LP-PRP samples were immediately assayed and analyzed to measure protein concentrations.

RESULTS

BMC had a significantly higher interleukin 1 receptor antagonist (IL-1Ra) concentration than all other preparations (all P < .0009). LR-PRP also had a significantly higher IL-1Ra concentration than LP-PRP (P = .0006). There were no significant differences in IL-1Ra concentration based on age, sex, body mass index, or chronicity of injury in all preparations. LR-PRP had significantly higher concentrations of platelet-derived growth factor AA (PDGF-AA) and PDGF-AB/BB than all other preparations (all P < .0006). LR-PRP also had significantly higher concentrations of matrix metalloproteinase 1 (MMP-1) and soluble CD40 ligand than all other preparations (all P < .004). LP-PRP had significantly higher concentrations of MMPs, namely MMP-2, MMP-3, and MMP-12, than all other preparations (all P < .007).

CONCLUSION

BMC is a clinically relevant source of anti-inflammatory biologic therapy that may be more effective in treating osteoarthritis and for use as an intra-articular biologic source for augmented healing in the postsurgical inflammatory and healing phases, owing to its significantly higher concentration of IL-1Ra as compared with LR-PRP and LP-PRP. Additionally, LR-PRP had a significantly higher concentration of IL-1Ra than LP-PRP. In cases where increased vascularity and healing are desired for pathological or injured tissues, including muscle and tendon, LR-PRP may be optimal given its higher overall concentrations of PDGF, TGF-β, EGF, VEGF, and soluble CD40 ligand.

The Role of Bone Marrow Aspirate Concentrate for the Treatment of Focal Chondral Lesions of the Knee: A Systematic Review and Critical Analysis of Animal and Clinical Studies

PURPOSE

To summarize currently available data regarding the use of bone marrow aspirate concentrate (BMAC) for the treatment of focal chondral lesions of the knee in experimental animal models and human clinical studies.

METHODS

A systematic review searching for the terms "(bone marrow)" AND "(aspirate OR concentrate)" AND "(cartilage OR chondral OR osteochondral)" was performed in the databases PubMed, Cochrane Central Register of Controlled Trials, and Google Scholar regarding the use of BMAC for the treatment of focal chondral lesions of the knee. The inclusion criteria were animal and clinical studies published in English that used autologous BMAC to treat focal chondral defects of the knee. We excluded studies that evaluated nonconcentrated preparations of bone marrow aspirate or preparations that were culture expanded.

RESULTS

A total of 23 studies were included: 10 studies performed in animal models and 13 human clinical studies. Animal studies showed inconsistent outcomes regarding the efficacy of BMAC for the treatment of chondral or osteochondral lesions, assessed by gross morphology, second-look arthroscopy, magnetic resonance imaging, histology, immunohistochemistry, mechanical testing, and micro-tomography. Chondral defect filling was achieved with fibrocartilage or "hyaline-like" cartilage. Cells present in BMAC did not meet the criteria to be characterized as mesenchymal stem cells according to the International Society for Cell Therapy because freshly isolated cells failed to show tri-lineage differentiation. Overall, all clinical studies, independent of the study group or level of evidence, reported improved clinical outcomes and higher macroscopic, magnetic resonance imaging, and histology scores. Comparative trials favored BMAC over microfracture and reported equivalent outcomes between BMAC and matrix-induced autologous chondrocyte implantation. However, clinical studies were scant and showed low scientific rigor, poor methodologic quality, and low levels of evidence on average.

CONCLUSIONS

Although clinical success in short-term and midterm applications has been suggested for the application of BMAC for the restoration of cartilage defects in lesions of the knee, current study designs are generally of low scientific rigor. In addition, clinical applications of this technology in animal model investigations have shown inconsistent outcomes. Thus, clinicians should apply this technology cautiously.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III, and IV evidence studies.

Assessing clinical implications and perspectives of the pathophysiological effects of erythrocytes and plasma free hemoglobin in autologous biologics for use in musculoskeletal regenerative medicine therapies. A review

Autologous biologics, defined as platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMC), are cell-based therapy treatment options in regenerative medicine practices, and have been increasingly used in orthopedics, sports medicine, and spinal disorders. These biological products are produced at point-of-care; thereby, avoiding expensive and cumbersome culturing and expansion techniques.

Numerous commercial PRP and BMC systems are available but reports and knowledge of bio-cellular formulations produced by these systems are limited. This limited information hinders evaluating clinical and research outcomes and thus making conclusions about their biological effectiveness. Some of their important cellular and protein properties have not been characterized, which is critical for understanding the mechanisms of actions involved in tissue regenerative processes. The presence and role of red blood cells (RBCs) in any biologic has not been addressed extensively. Furthermore, some of the pathophysiological effects and phenomena related to RBCs have not been studied. A lack of a complete understanding of all of the biological components and their functional consequences hampers the development of clinical standards for any biological preparation.

This paper aims to review the clinical implications and pathophysiological effects of RBCs in PRP and BMC; emphasizes hemolysis, eryptosis, and the release of macrophage inhibitory factor; and explains several effects on the microenvironment, such as inflammation, oxidative stress, vasoconstriction, and impaired cell metabolism.

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Different biological formulations optimize disease specific regenerative treatment protocols.

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Disintegrated RBC's release harmful components to regenerative therapy treatment vials.

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The effectiveness of MSC injection depends on the quality of the bone marrow aspiration procedure.

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PRP and BMC should contain minimal to no erythrocytes.

Editorial Commentary: Now Is the Time to Discover How and Why Platelet-Rich Plasma Works in Cartilage

From the initial overenthusiasm for platelet-rich plasma (PRP) that considered it a panacea for all orthopaedic conditions to the other extreme that heavily criticized it as having a placebo effect, we are now entering a period in which significant evidence suggests that application of PRP provides clinical benefit for various indications. And although high-quality studies exist to show clinical improvement for cartilage pathologic conditions, there is not sufficient support from basic science research to explain PRP's mechanism of action or adequate characterization of its properties and behavior.

Regenerative Sports Medicine: Past, Present, and Future (Adapted From the PASSOR Legacy Award Presentation; AAPMR; October 2016)

Regenerative medicine has shown dramatic expanse and evolution in the past decade. Within that milieu, physiatrists are taking an active role in research, clinical care delivery, and education. The purpose of this review is to provide a balance among evidence, theory, experience, clinical trends, and the foreseeable future. We focus on the literature that reports the research with the best methodology in each practice area, recognizing that the level of evidence varies substantially among different treatment modalities and conditions. The following elements are included: an overview of the evolution of currently available regenerative techniques, evidence base for each available modality (prolotherapy, platelet rich plasma, bone marrow aspirate concentrate and stem cells, adipose-derived stem cells, and amniotic tissue products), general principles in the application of these treatments, and discussion and a vision of what lies ahead. We expect that practitioners will use this review to facilitate clinical decision making and to provide a core knowledge base to assist when counseling patients. LEVEL OF EVIDENCE: IV.

Editorial Commentary: Not All Bone Marrow Aspirate Concentrates Are the Same: The Necessity of Detailed Reporting and Other Lessons Learned From Cell-based Treatments in Orthopaedics

Bone marrow aspirate concentrates have become a popular therapeutic approach for several musculoskeletal conditions. A plethora of different preparations exist that make difficult to evaluate their clinical outcome and, thus, to make safe conclusions for their effectiveness. The first step for this assessment is comprehensive and reliable reporting of all the important variables that would allow characterization of their content and properties. This is critical for the understanding of their mechanism of action and the identification of the proper indications based on patient and disorder characteristics that could potentially lead to their effective application in clinical scenarios.

Concentrated Bone Marrow Aspirate-Coated Hydroxyapatite for Reconstruction of Small-to-Moderate-Sized Mandibular Defects Caused by the Removal of Benign Pathologies

Purpose:

The aim of this study was to evaluate the bone regeneration potential of concentrated bone marrow aspirate (BMA)-coated hydroxyapatite (HA) for reconstruction of mandibular defects caused by the removal of benign pathologies.

Patients and Methods:

This prospective clinical study included ten patients with histopathologically proven benign pathologies of the mandible measuring <5 cm anteroposteriorly, who were treated with enucleation or marginal resection, followed by autologous concentrated BMA-coated synthetic biphasic HA (HA and beta-tricalcium phosphate) graft placement. Clinical and radiological evaluations of grafted sites of the mandible were done at 1 week, 1, 3, and 6 months postoperatively using Irwin's radiologic staging and grayscale histogram.

Results:

All patients (10/10, 100%) had proper incorporation of the graft with the normal adjacent bone. Grayscale histogram revealed the initial stages of graft resorption, followed by formation of new bone-grafted sites. No complications such as infection and total graft loss were encountered except for one patient who had partial wound dehiscence that responded well to local wound care and resuturing.

Conclusion:

Concentrated BMA-coated synthetic HA effectively promotes bone regeneration in small-to-moderate-sized defects of the mandible.