Bone Marrow Aspirate Concentrate for Cartilage Defects of the Knee: From Bench to Bedside Evidence

T cells and macrophages jointly modulate osteogenesis of mesenchymal stromal cells

Approximately 5%-10% of fractures go on to delayed healing and nonunion, posing significant clinical, economic, and social challenges. Current treatment methods involving open bone harvesting and grafting are associated with considerable pain and potential morbidity at the donor site. Hence, there is growing interest in minimally invasive approaches such as bone marrow aspirate concentrate (BMAC), which contains mesenchymal stromal cells (MSCs), macrophages (Mφ), and T cells. However, the use of cultured or activated cells for treatment is not yet FDA-approved in the United States, necessitating further exploration of optimal cell types and proportions for effective bone formation. As our understanding of osteoimmunology advances, it has become apparent that factors from anti-inflammatory Mφ (M2) promote bone formation by MSCs. Additionally, M2 Mφ promote T helper 2 (Th2) cells and Treg cells, both of which enhance bone formation. In this study, we investigated the interactions among MSCs, Mφ, and T cells in bone formation and explored the potential of subsets of BMAC. Coculture experiments were conducted using primary MSCs, Mφ, and CD4+ T cells at specific ratios. Our results indicate that nonactivated T cells had no direct influence on osteogenesis by MSCs, while coculturing MSCs with Mφ and T cells at a ratio of 1:5:10 positively impacted bone formation. Furthermore, higher numbers of T cells led to increased M2 polarization and a higher proportion of Th2 cells in the early stages of coculture. These findings suggest the potential for enhancing bone formation by adjusting immune and mesenchymal cell ratios in BMAC. By understanding the interactions and effects of immune cells on bone formation, we can develop more effective strategies and protocols for treating bone defects and nonunions. Further studies are needed to investigate these interactions in vivo and explore additional factors influencing MSC-based therapies.

Microfragmented Adipose Tissue Associated With Collagen Membrane in the Treatment of Focal Knee Cartilage Defect

Focal articular cartilage defects are an important factor that leads to dysfunction of the knee joint. Several different surgical approaches have been tried, most of them showing poor results in the long term. The use of orthobiologics in the context of focal chondral lesion has emerged as a potential tool in the treatment of this condition. In this article, we present a surgical technique for the treatment of focal chondral lesions using a collagen membrane associated with microfragmented adipose tissue graft.

Current Review of Regenerative Medicine Therapies for Spine-Related Pain

PURPOSE OF REVIEW

Persistent spinal pain syndromes are pervasive and lead to functional impairment, increased healthcare utilization, potential disability, and high societal costs. Spinal (cervical, thoracic, lumbar, and sacroiliac joint) pain includes mechanical, degenerative, inflammatory, oncologic, and infectious etiologies. Regenerative medicine is a novel biotechnology targeting mechanical, degenerative, and inflammatory conditions believed to cause pain. Preparations including platelet-rich plasma, mesenchymal stem cells (adipose tissue and bone marrow aspirate concentrates), and growth factors are derived from an autologous donor. The goal of intervention through guided injection of the regenerative media is to reduce inflammation and reverse the degenerative cascade in hopes of restoring normal cellular composition (physiologic homeostasis) and anatomical function to improve pain and function. The authors review limited research supporting the use of platelet-rich plasma injections for facet joint arthropathy and sacroiliac joint pain compared to traditional steroid treatments, as well as the use of platelet rich plasma or mesenchymal stem cells for lumbar discogenic and radicular pain.

RECENT FINDINGS

Current evidence to support regenerative medicine for spine-related pain is limited. Although several studies demonstrated a reduction in pain, many of these studies had a small number of participants and were case series or prospective trials. Regenerative medicine treatments lack evidence for the treatment of spine-related pain. Large randomized controlled trials are needed with consistent study protocols to make further recommendations.

Surgical Applications for Bone Marrow Aspirate Concentrate

Bone marrow aspirate concentrate (BMAC) is an autologous orthobiologic agent that may be of benefit in specific surgical scenarios. Composed of elements isolated from bone marrow, including mesenchymal stromal cells, bone marrow-derived platelets, red and white blood cells, and hematopoietic precursors, BMAC has gained appeal for its potential to slow the progression of chondral degeneration, improve function, and provide symptomatic relief. BMAC is typically prepared during the final stages of a surgical procedure, beginning with bone marrow aspirate harvested from the iliac crest, distal femur, body of the ilium, or proximal humerus and then centrifuged to yield concentrated marrow cells. In a published technique for BMAC use in arthroscopic acetabular labral repair, 120 mL of BMA is harvested from the body of the ilium and then centrifuged to yield approximately 4 to 6 mL of BMAC. The biologic activity of BMAC is 2-fold: (1) mesenchymal stromal cells are pluripotent stem cells that stimulate a robust tissue response for cartilage repair through their potential to differentiate into chondrocytes that induce chondrogenesis, and (2) bone marrow-derived platelets produce growth factors, cytokines, and chemokines that promote collagen synthesis, wound healing, and suppression of proinflammatory cytokines. To date, BMAC has shown promise as an efficacious adjuvant therapy. When comparing patient outcomes, studies have found that patients receiving BMAC achieved lower rates of revision rotator cuff repair, higher functional outcome scores following arthroscopic acetabular labral repair, and significant reductions in pain levels in the context of knee cartilage defects. These findings, however, must be interpreted with caution, as there remains a paucity of randomized controlled trials investigating the mid- and long-term efficacy of BMAC. Overall, as treatments for patients with both progressive chondral degeneration and acute orthopaedic injuries continue to evolve, BMAC serves as promising orthobiologic therapy to improve outcomes.

Bone marrow aspirate and bone marrow aspirate concentrate: Does the literature support use in long-bone nonunion and provide new insights into mechanism of action?

PURPOSE

To assess the use of bone marrow aspirate (BM) and bone marrow aspirate concentrate (BMAC) in the treatment of long-bone nonunion and to understand mechanism of action.

METHODS

A systematic review of PubMed and EBSCOHost was completed to identify studies that investigated the use of BM or BMAC for the diagnosis of delayed union and/or nonunion of long-bone fractures. Studies of isolated bone marrow-mesenchymal stem cells (BM-MSCs) and use in non-long-bone fractures were excluded. Statistical analysis was confounded by heterogeneous fracture fixation methods, treatment history, and scaffold use.

RESULTS

Our initial search yielded 430 publications, which was screened down to 25 studies. Successful treatment in aseptic nonunion was reported at 79-100% (BM) and 50-100% (BMAC). Septic nonunion rates were slightly better at 73-100% (BM) and 83.3-100% (BMAC). 18/24 studies report union rates > 80%. One study reports successful treatment of septic nonunion with BMAC and no antibiotics. A separate study reported a significant reduction in autograft reinfection rate when combined with BMAC (P = 0.009). Major adverse events include two deep infections at injection site and one case of heterotopic ossification. Most studies note transient mild donor site discomfort and potential injection site discomfort attributed to needle size.

CONCLUSION

The current literature pertaining to use of BM/BMAC for nonunion is extremely heterogeneous in terms of patient population and concomitant treatment modalities. While results are promising for use of BM/BMAC with other gold standard treatment methodologies, the literature requires additional Level I data to clarify the impact of role BM/BMAC in treating nonunion when used alone and in combination with other modalities.

LEVEL OF EVIDENCE

Level III.

Synovium-Derived and Bone-Derived Mesenchymal Stem/Stromal Cells from Early OA Patients Show Comparable In Vitro Properties to Those of Non-OA Patients

Degenerative disorders like osteoarthritis (OA) might impair the ability of tissue-resident mesenchymal stem/stromal cells (MSCs) for tissue regeneration. As primary cells with MSC-like properties are exploited for patient-derived stem cell therapies, a detailed evaluation of their in vitro properties is needed. Here, we aimed to compare synovium-derived and bone-derived MSCs in early hip OA with those of patients without OA (non-OA). Tissues from three synovial sites of the hip (paralabral synovium, cotyloid fossa, inner surface of peripheral capsule) were collected along with peripheral trabecular bone from 16 patients undergoing hip arthroscopy (8 early OA and 8 non-OA patients). Primary cells isolated from tissues were compared using detailed in vitro analyses. Gene expression profiling was performed for the skeletal stem cell markers podoplanin (PDPN), CD73, CD164 and CD146 as well as for immune-related molecules to assess their immunomodulatory potential. Synovium-derived and bone-derived MSCs from early OA patients showed comparable clonogenicity, cumulative population doublings, osteogenic, adipogenic and chondrogenic potential, and immunophenotype to those of non-OA patients. High PDPN/low CD146 profile (reminiscent of skeletal stem cells) was identified mainly for non-OA MSCs, while low PDPN/high CD146 mainly defined early OA MSCs. These data suggest that MSCs from early OA patients are not affected by degenerative changes in the hip. Moreover, the synovium represents an alternative source of MSCs for patient-derived stem cell therapies, which is comparable to bone. The expression profile reminiscent of skeletal stem cells suggests the combination of low PDPN and high CD146 as potential biomarkers in early OA.

Potential therapeutic strategies for osteoarthritis via CRISPR/Cas9 mediated gene editing

Osteoarthritis (OA) is an incapacitating and one of the most common physically degenerative conditions with an assorted etiology and a highly complicated molecular mechanism that to date lacks an efficient treatment. The capacity to design biological networks and accurately modify existing genomic sites holds an apt potential for applications across medical and biotechnological sciences. One of these highly specific genomes editing technologies is the CRISPR/Cas9 mechanism, referred to as the clustered regularly interspaced short palindromic repeats, which is a defense mechanism constituted by CRISPR associated protein 9 (Cas9) directed by small non-coding RNAs (sncRNA) that bind to target DNA through Watson-Crick base pairing rules where subsequent repair of the target DNA is initiated. Up-to-date research has established the effectiveness of the CRISPR/Cas9 mechanism in targeting the genetic and epigenetic alterations in OA by suppressing or deleting gene expressions and eventually distributing distinctive anti-arthritic properties in both in vitro and in vivo osteoarthritic models. This review aims to epitomize the role of this high-throughput and multiplexed gene editing method as an analogous therapeutic strategy that could greatly facilitate the clinical development of OA-related treatments since it's reportedly an easy, minimally invasive technique, and a comparatively less painful method for osteoarthritic patients.

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

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

Biomaterials augmented with filtered bone marrow aspirate for the treatment of talar osteochondral lesions. A comparison of clinical and cellular parameters

BACKGROUND

Biomaterials augmented with Bone Marrow Aspirate Concentrate (BMAC) are becoming increasingly utilized in the cartilage treatment. However, the potential role of cellular parameters in the intraoperatively applied BMAC have yet to be elucidated.

PURPOSE

(A) To evaluate clinical outcomes and safety of a combined single-step approach with scaffolds (fibrin glues, collagen gels, collagen-hydroxyapatite membrane) and filtered Bone Marrow Aspirate (fBMA) for the treatment of osteochondral lesions of the talus (OLTs). (B) To identify significant factors for postoperative improvements, considering cellular parameters as potential predictors.

METHODS

All the patients operated on due to OLTs by the combination above were selected from the hospital registry database (35 pts, years 16-55, and minimally 1 year follow-up). Treatment outcomes were followed clinically with Patient-reported outcome measures (PROMs), and by pursuing serious adverse events (SAE) and graft failures (GF). Cellular parameters of the injected fBMA were determined. Pre- and postoperative PROMs values were compared to evaluate postoperative improvements. Multivariable regression models were applied to identify potential factors (demographics, medical history, joint and lesion characteristics, scaffold type, surgical and cellular parameters) that predict the treatment outcomes.

RESULTS

At the mean follow-up of 32.2 (12.5) months, all Foot and Ankle Outcome Score (FAOS) and European Quality of Life in Five Dimensions Three-Level (EQ-5D-3 L) values improved significantly. 4 (11%) SAE (3 arthrofibrosis, one hardware removal), and 3 (9%) GF occurred. Female gender and concomitant procedures were the main negative predictors for postoperative outcomes. The number of fibroblast colony forming units (CFU-F) or their proportion among total nucleated cells (CFU-F/TNC) were positively correlated with the improvements of some PROMs.

CONCLUSIONS

Scaffolds augmented with fBMA proved as an adequate and safe approach for OLTs treatment. Cellular parameters seem to influence the treatment outcomes, thus further attention should be given to the intraoperatively applied products.

LEVEL OF EVIDENCE

Level IV.

The 50 Most Cited Publications on Concentrated Bone Marrow Aspirate with Application in Orthopaedic Surgery

Concentrated bone marrow aspirate (cBMA) has garnered widespread and increasing attention in recent years. We aimed to characterize the most influential articles in cBMA research while clarifying controversies surrounding its use and clinical efficacy and identifying important areas on which to focus future research efforts. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched to identify the top 50 most cited publications on orthopaedic cBMA research. Publication and study characteristics were extracted, and Spearman's correlations were calculated to assess the relationship between citation data and level of evidence. The top 50 articles were published between the years 1996 and 2018, with 58% published in the year 2010 or later. Of the 29 studies for which level of evidence was assessed, the majority were Level IV (24, 83%). Twenty-one articles (42%) were classified as basic science or translational (9 cell culture, 8 animal study, and 4 using human blood samples). Application to treat cartilage defects was the most common focus of studies (17 studies, 34%), followed by analysis of cBMA composition (14 studies, 28%). No correlation was found between rank, citation rate, or year of publication and level of evidence. The most influential articles on cBMA are recent and consist of a majority low level of evidence studies. Cohort studies were the most common study type among the top 50 most cited articles, while basic science articles were relatively less common. These results suggest a rapidly evolving field with the potential to better explain inconsistent clinical results with improved understanding and documentation of basic science concepts in addition to large-scale, prospective clinical trials. Orthobiologics especially cBMA holds great promise for the future, and higher level clinical trials will help better define the best clinical uses for this treatment.

Orthobiologics as an adjunct in treatment of femoroacetabular impingement syndrome: cell-based therapies facilitate improved postoperative outcomes in the setting of acetabular chondral lesions-a systematic review

PURPOSE

To evaluate studies utilizing orthobiologics in the management of femoroacetabular impingement syndrome (FAIS) to (1) assess the indications for usage, and (2) analyze patient-reported outcome measures (PROM) following treatment. It was hypothesized that orthobiologics would (1) be utilized for symptomatic FAIS in the setting of labral or chondral pathology, and (2) improve PROM at most recent follow-up.

METHODS

The Pubmed, Ovid Medline, Cochrane, and Web of Science databases were searched for clinical studies evaluating orthobiologics [hyaluronic acid (HA), platelet-rich plasma (PRP), or cell-based therapy (CBT) for treatment of FAIS. Exclusion criteria included orthobiologics used in conjunction with cartilage transfer or scaffolding procedures and a primary indication other than FAIS. Data collection included patient demographics, indications, and baseline and most recent PROM.

RESULTS

Eleven studies (one level I, four level II, four level III, and two level IV evidence) met inclusion criteria, consisting of 440 patients with mean ages ranging from 32.8 to 47 years. All 11 studies demonstrated an improvement in PROM from baseline to most-recent follow-up. Four studies administered PRP either intraoperatively or the day after surgery as an adjunct to labral repair. CBT was used intraoperatively in the setting of acetabular chondral lesions (three studies) and labral repair (one study). When comparing to a control group at most recent follow-up, three PRP cohorts demonstrated similar PROM (n.s.), while one PRP group exhibited worse visual analog pain scores (2.5 vs. 3.4, p = 0.005) and modified Harris Hip Scores (mHHS) (82.6 vs. 78.7, p = 0.049). The four CBT studies reported favorable results compared to a control group, with a significantly higher mHHS at most recent follow-up or mean improvement from baseline in Hip Outcome Score-Activities of Daily Living (p < 0.05). Three studies reported on HA, which was utilized exclusively in the nonoperative setting.

CONCLUSIONS

Intraoperative PRP and CBT have been commonly reported in the setting of hip arthroscopy for labral repairs and acetabular chondral lesions, respectively. The CBT cohorts demonstrated more favorable PROM at most recent follow-up when compared to a control group, though these results should be interpreted with caution due to heterogeneity of orthobiologic preparations.

LEVEL OF EVIDENCE

IV.

Clinical Applications of PRP: Musculoskeletal Applications, Current Practices and Update

Musculoskeletal tissues are often subjected to deleterious effects stemming from traumatic injuries or degenerative pathologies, which can impede the body's natural repair response. The advent of regenerative medicine has emerged as a promising therapeutic approach in modern patient care. Among the interventions in this cutting-edge field, platelet-rich plasma (PRP) and cell-based therapies, such as mesenchymal stem cells, have garnered significant attention. In this article, we endeavor to provide an overview of the current practices and recent developments in PRP therapy, with a particular emphasis on the clinical applications for musculoskeletal pathologies.

Particulated Costal Hyaline Cartilage Allograft With Subchondral Drilling Improves Joint Space Width and Second-Look Macroscopic Articular Cartilage Scores Compared With Subchondral Drilling Alone in Medial Open-Wedge High Tibial Osteotomy

PURPOSE

To compare the articular cartilage regeneration based on second-look arthroscopy in patients who underwent medial open-wedge high tibial osteotomy (MOWHTO) combined with particulated costal hyaline cartilage allograft (PCHCA) implantation with those who underwent MOWHTO and subchondral drilling (SD). Moreover, we compared the clinical and radiographic outcomes between the groups.

METHODS

From January 2014 to November 2020, patients with full-thickness cartilage defect on the medial femoral condyle who underwent MOWHTO combined with PCHCA (group A) or SD (group B) were reviewed. Fifty-one knees were matched after propensity score matching. The status of regenerated cartilage was classified according to the International Cartilage Repair Society-Cartilage Repair Assessment (ICRS-CRA) grading system and Koshino staging system, based on second-look arthroscopic findings. Clinically, the Knee Injury and Osteoarthritis Outcome Score, the Western Ontario and McMaster Universities Osteoarthritis Index, and range of motion were compared. Radiographically, we compared the differences in the minimum joint space width (JSW) and change in JSW.

RESULTS

The average age was 55.5 years (range, 42-64 years), and the average follow-up period was 27.1 months (range, 24-48 months). Group A showed a significantly better cartilage status than group B based on the ICRS-CRA grading system and Koshino staging system (P < .001 and <.001, respectively). There were no significant differences in clinical and radiographic outcomes between groups. In group A, the minimum JSW at the last follow-up was significantly increased than that before surgery (P = .013), and a significantly greater increase in JSW was observed in group A (P = .025).

CONCLUSIONS

When performed with MOWHTO, the combination of SD and PCHCA was associated with superior articular cartilage regeneration on the ICRS-CRA grading and Koshino staging on second-look arthroscopy performed at a minimum of 2 years follow-up than SD alone. However, there was no difference in clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Treatment of Chondral Lesions in the Knee

Articular cartilage injuries are common and lead to early joint deterioration and osteoarthritis. Articular cartilage repair techniques aim at forming a cartilaginous neo-tissue to support the articular load and prevent progressive degeneration. Several techniques are available for this purpose, such as microfracture and chondrocyte transplantation. However, the procedural outcome is often fibrocartilage, which does not have the same mechanical resistance as cartilaginous tissue. Procedures with autologous osteochondral graft have a morbidity risk, and tissue availability limits their use. As such, larger lesions undergo osteochondral transplantation using fresh or frozen grafts. New techniques using minced or particulate cartilage fragments or mesenchymal stem cells are promising. This paper aims to update the procedures for treating chondral lesions of the knee.

Revision Lateral Femoral Condyle Osteochondral Allograft Transplantation With the Snowman Technique After Failed Previous Oblong Osteochondral Allograft

Osteochondral allograft transplantation provides components of both cartilage and subchondral bone and can be used in large and multifocal defects where autologous procedures are limited by donor-site morbidity. Osteochondral allograft transplantation is particularly appealing in the management of failed cartilage repair, as larger defects and subchondral bone involvement are often present, and the use of multiple overlapping plugs might be considered. The described technique provides our preoperative workup and reproducible surgical approach for patients who have undergone previous osteochondral transplantation with graft failure and are young, active patients who would not be otherwise suited for a knee arthroplasty procedure.

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.

Bone Healing Gone Wrong: Pathological Fracture Healing and Non-Unions-Overview of Basic and Clinical Aspects and Systematic Review of Risk Factors

Bone healing is a multifarious process involving mesenchymal stem cells, osteoprogenitor cells, macrophages, osteoblasts and -clasts, and chondrocytes to restore the osseous tissue. Particularly in long bones including the tibia, clavicle, humerus and femur, this process fails in 2-10% of all fractures, with devastating effects for the patient and the healthcare system. Underlying reasons for this failure are manifold, from lack of biomechanical stability to impaired biological host conditions and wound-immanent intricacies. In this review, we describe the cellular components involved in impaired bone healing and how they interfere with the delicately orchestrated processes of bone repair and formation. We subsequently outline and weigh the risk factors for the development of non-unions that have been established in the literature. Therapeutic prospects are illustrated and put into clinical perspective, before the applicability of biomarkers is finally discussed.

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.

Use of bone marrow derived mesenchymal stem cells for the treatment of osteoarthritis: A retrospective long-term follow-up study

Background

Available studies suggest that bone marrow concentrate, highly enriched in mesenchymal stem cells, is a potentially encouraging treatment for knee osteoarthritis. The aim of this retrospective study was to evaluate the clinical outcome in patients affected by this condition after treatment with autologous bone marrow aspirate concentrate (BMAC).

Methods

55 patients who had undergone a single intra-articular injection of BMAC were administered two questionnaires to clinically evaluate their condition based on patient-reported outcome measures before treatment and at follow-up.

Results

Analysis of the data collected indicates that patients experienced improvements in Tegner, VAS and WOMAC scores and that all outcomes at the follow-up improved in a statistically significant manner compared to outcomes at baseline.

Conclusions

The changes observed in the different scores examined suggest that a single BMAC injection seems to be a beneficial and safe treatment for knee osteoarthritis.

Hip Arthroscopy With Bone Marrow Aspirate Injection for Patients With Symptomatic Labral Tears and Early Degenerative Changes Shows Similar Improvement Compared With Patients Undergoing Hip Arthroscopy With Symptomatic Labral Tears Without Arthritis

PURPOSE

To define the clinical effect of intra-articular injection of iliac crest-derived bone marrow aspirate concentrate (BMAC) at the time of hip arthroscopy in patients with symptomatic labral tears and early radiographic degenerative changes.

METHODS

A retrospective review of a prospectively collected hip registry database was performed. Patients with symptomatic labral tears and Tönnis grade 1 or 2 degenerative changes who underwent labrum-preserving hip arthroscopy with BMAC injection were included and were matched with patients who underwent hip arthroscopy without BMAC injection. Patient-reported outcomes (PROs) collected preoperatively and up to 2 years postoperatively included the modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sport, and International Hip Outcome Tool 33 score. Clinical relevance was measured with the minimal clinically important difference, patient acceptable symptom state, and substantial clinical benefit for each outcome score.

RESULTS

A total of 35 patients underwent labrum-preserving hip arthroscopy with BMAC injection and were matched with 35 control patients. There were no differences in demographic characteristics between the groups (P > .05). The BMAC group consisted of 22 patients (62.9%) with Tönnis grade 1 changes and 13 (37.1%) with Tönnis grade 2 changes, whereas all 35 control patients had Tönnis grade 0 hips. All PROs were significantly improved in both groups at 2 years, with no difference in improvement. The rate of failure requiring conversion to total hip arthroplasty was 14.3% (mean, 1.6 years postoperatively) in the BMAC group and 5.7% (mean, 7 years postoperatively) in the control group (P = .09). The difference in the frequency of patients achieving the minimal clinically important difference, patient acceptable symptom state, and substantial clinical benefit was not statistically significant between cohorts.

CONCLUSIONS

In a challenging group of patients with symptomatic labral tears and early radiographic degenerative changes, hip arthroscopy with BMAC injection results in statistically and clinically significant improvement in PROs comparable to a group of patients with nonarthritic hips undergoing hip arthroscopy at short-term follow-up.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Interventional Therapies for Osteoarthritis: An Update

Osteoarthritis (OA) is one of the most common diseases worldwide and is expected to increase in incidence as the age of the general population rises. Both oral medications, such as NSAIDs, and surgical treatments used for OA management have limitations. Demand is rising for minimally invasive techniques such as intraarticular injections and percutaneous interventions for use in place of or in conjunction with oral medications and surgical therapies, and the past 2 decades have seen a rapid expanse in both pharmacologic and nonpharmacologic minimally invasive OA treatments. Image guidance with fluoroscopy, CT, or ultrasound is often used in conjunction with these procedures to achieve precise treatment localization to achieve maximal therapeutic effect. The choice of modality used for image guidance is often influenced by clinician experience, patient characteristics, and equipment availability. This article reviews the mechanisms of action, contraindications, complications, and efficacy of conventional and developing minimally invasive OA treatments. The minimally invasive treatment options described in this Review include therapeutic injections such as antiinflammatory agents, viscosupplements, and biologics, as well as nonpharmacologic treatments of subchondroplasty, nerve ablation, genicular artery embolization, intraarticular pulsed radiofrequency therapy, and MRI-guided focused ultrasound therapy.

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.

Treatment Options for Patellofemoral Arthritis

PURPOSE OF REVIEW

To present a synthesis of recent literature regarding the treatment of patellofemoral arthritis RECENT FINDINGS: Risk factors of PFJ OA include patella malalignment or maltracking, injury to supportive structures including the MPFL, dysfunction of hamstring and quadriceps coordination, lower limb alignment, trochlear dysplasia, patellar trauma, or ACL surgery. Special physical exam maneuvers include patellar grind test, apprehension test, and lateral patellar tilt angle. Radiographs that should be obtained first-line include weight bearing bilateral AP, lateral, and Merchant views. CT and MRI are used to assess trochlear dysplasia, excessive patellar height, and TT-TG distance. Non-operative management options discussed include non-pharmacologic treatment (patient education, self-management, physical therapy, weight loss), ESWT, cold therapy, taping, bracing, and orthotics. Pharmacologic management options discussed include NSAIDs, acetaminophen, oral narcotics, and duloxetine. Injection therapies include glucocorticoids, hyaluronic acid, PRP, and other regenerative therapies (BMAC, adipose, or mesenchymal stem cells). Other treatment options include radiofrequency ablation and botulinum toxin. The algorithm for the surgical treatment of PFJ OA can begin with arthroscopic assessment of the PF articular cartilage to address mechanical symptoms and to evaluate/treat lateral soft tissue with or without overhanging lateral osteophytes. If patients fail to have symptomatic improvement, a TTO can be considered in those patients less than 50 years of age or active patients >50 years old. In patients with severe PFJ OA, refractory to the above treatments, PFA should be considered. While early PFA design and technique were less than encouraging, more recent implant design and surgical technique have demonstrated robust results in the literature. Patellofemoral osteoarthritis is a challenging orthopedic problem to treat, in that it can often affect younger patients, with otherwise well-functioning knees. It is a unique entity compared to TF OA with distinct epidemiology, biomechanics and risk factors and treatment options.

Does the Choice of Acellular Scaffold and Augmentation With Bone Marrow Aspirate Concentrate Affect Short-term Outcomes in Cartilage Repair? A Systematic Review and Meta-analysis

BACKGROUND

Matrix-induced chondrogenesis (MIC) is a promising treatment option for critical-size cartilage lesions of the knee; however, there exists substantial heterogeneity in the choice of acellular scaffold matrix for MIC cartilage repairs.

HYPOTHESIS

The choice of acellular matrix will not affect patient outcomes after MIC cartilage repair procedures, and the addition of concentrated bone marrow aspirate (cBMA) will improve short-term patient outcomes regardless of matrix choice.

STUDY DESIGN

Meta-analysis; Level of evidence, 4.

METHODS

Studies were stratified by matrix type: multilayered, single layered, and gel based. Continuous outcomes were analyzed with pairwise meta-analysis using the inverse variance model with random effects applied. Binary outcomes were analyzed as pooled proportions in a single-arm fashion; after which, reconstruction of relative risks (RRs) with confidence intervals was performed using the Katz logarithmic method.

RESULTS

A total of 876 patients were included: 469 received multilayered bioscaffolds; 238, gel-based scaffolds; and 169, single-layered scaffolds. The mean age of patients was 36.2 years (95% CI, 33.9 to 38.4), while the mean lesion size was 3.91 cm² (95% CI, 3.40 to 4.42). The weighted mean follow-up was 23.8 months (95% CI, 20.1 to 27.6). Multilayered bioscaffolds were most effective at improving visual analog scale scores (P = .03; weighted mean difference [WMD], -4.44 [95% CI, -4.83 to -4.06]; P < .001). There were significantly lower risks of incomplete defect filling for gel-based scaffolds when compared with multilayered scaffolds (RR, 0.78 [95% CI, 0.69 to 0.88]; P < .001) and single-layered scaffolds (RR, 0.58 [95% CI, 0.41 to 0.81]; P = .001). Augmentation with cBMA further improved clinical scores across all scaffolds, with significant improvements in Tegner score (P = .02), while decreasing incomplete defect filling rates as well. There was significantly greater improvement in visual analog scale scores (P = .01) for single-layered scaffolds with cBMA augmentation (WMD, -4.88 [95% CI, -5.38 to -4.37]; P < .001) as compared with single-layered scaffolds without cBMA augmentation (WMD, -4.08 [95% CI, -4.46 to -3.71]; P < .001). All significant improvements were below their respective minimum clinically important differences.

CONCLUSION

While cartilage repair with acellular scaffolds provides significant improvements in pain and function for patients, there is insufficient clinical evidence to suggest which scaffold material is the most superior in influencing such improvements. The enhancement of cartilage repair procedures with cBMA may provide further functional improvements and improve defect filling; however, more long-term evidence is required to evaluate the effects.

Endogenous Controls for the Evaluation of Osteoarthritis-Related miRNAs in Extracellular Vesicles from Bone-Marrow-Derived Mesenchymal Stromal Cells and the Impact of Osteoarthritis Synovial Fluid

Bone-marrow-derived stromal cells (BMSCs) have emerged as promising therapeutic option for the treatment of osteoarthritis (OA) due to their tissue regenerative and anti-inflammatory features. BMSCs’ clinical potential is mainly ascribed to their released factors and extracellular vesicles (EVs), whose therapeutic portfolio may be modulated by the environment in vivo or specific priming in vitro. Within the array of molecules shaping EVs’ power, miRNAs are considered privileged players. In this frame, a correct EV-miRNA detection and quantification is mandatory to understand and possibly boost BMSCs potential, either when envisioned as cell therapeutics or when proposed as producer of cell-free and clinical grade EVs. The aim of this study is to identify reliable reference genes (RGs) to study miRNAs in BMSC-EVs cultivated under standard or OA synovial fluid (OA-SF). miR-23a-3p and miR-221-3p emerged as the best candidates, respectively. Moreover, when both conditions were analyzed together, miR-24-3p resulted the most stable RGs, allowing for a sharper comparison of EVs content, further validated on the OA-related miRNA-193b-5p. The different RG stability ranking depending on the culturing conditions, as well as its divergence with respect to adipose (ASCs) and amniotic (hAMSCs) MSCs, confirm that miRNA RG selection in EVs is a mandatory step and that the identification of the most reliable candidate is greatly depending on the cell type and culturing/environmental conditions.

Functional Outcomes of Arthroscopic Acetabular Labral Repair with and without Bone Marrow Aspirate Concentrate

BACKGROUND

Osteoarthritis (OA) of the hip is a debilitating condition associated with inferior outcomes in patients undergoing hip arthroscopy. To provide symptom relief and improve outcomes in these patients, bone marrow aspirate concentrate (BMAC) has been applied as an adjuvant therapy with the hope of halting progression of cartilage damage. The current study examined the clinical efficacy of BMAC application in patients undergoing arthroscopic acetabular labral repair by comparing patient-reported outcome measures (PROMs) between groups with and without BMAC application.

METHODS

Patients who received BMAC during arthroscopic acetabular labral repair from December 2016 to June 2019 were compared with a control cohort that underwent the same procedure but did not receive BMAC from November 2013 to November 2016. Patients in both cohorts were asked to prospectively complete PROMs prior to surgery and at 3, 6, 12, and 24-month follow-up intervals; those who completed the PROMs at enrollment and the 12-month follow-up were included in the study. An a priori subgroup analysis was performed among patients with moderate cartilage damage (Outerbridge grade 2 or 3). The analyses were adjusted for any differences in baseline factors between groups.

RESULTS

Sixty-two patients with BMAC application were compared with 62 control patients without BMAC application. When compared with the no-BMAC cohort, the BMAC cohort did not report significantly different mean International Hip Outcome Tool-33 (iHOT-33) scores at any postoperative time point. However, when patients with moderate cartilage damage were compared across groups, the BMAC cohort reported significantly greater mean (95% confidence interval) scores than the no-BMAC cohort at the 12-month (78.6 [72.4 to 84.8] versus 69.2 [63.3 to 75.2]; p = 0.035) and 24-month (82.5 [73.4 to 91.6] versus 69.5 [62.1 to 76.8]; p = 0.030) follow-up. Similarly, these patients reported greater score improvements at 12 months (37.3 [30.3 to 44.3] versus 25.4 [18.7 to 32.0]; p = 0.017) and 24 months (39.6 [30.4 to 48.7] versus 26.4 [19.1 to 33.8]; p = 0.029).

CONCLUSIONS

Patients with moderate cartilage injury undergoing arthroscopic acetabular labral repair with BMAC application reported significantly greater functional improvements when compared with similar patients without BMAC application.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Allogenic umbilical cord blood-derived mesenchymal stromal cell implantation was superior to bone marrow aspirate concentrate augmentation for cartilage regeneration despite similar clinical outcomes

PURPOSE

The aim of this study was to compare clinical and second-look arthroscopic outcomes between bone marrow aspirate concentrate (BMAC) augmentation and human umbilical cord blood-derived mesenchymal stromal cell (hUCB-MSC) implantation in high tibial osteotomy (HTO) for medial compartmental knee osteoarthritis and identify the relationship between articular cartilage regeneration and HTO outcomes.

METHODS

A total of 176 patients who underwent HTO combined with a BMAC or hUCB-MSC procedure for medial compartment osteoarthritis (Kellgren-Lawrence grade 3) between June 2014 and September 2018 with a minimum follow-up of 2 years were reviewed. After HTO, multiple holes were drilled at cartilage defect sites of the medial femoral condyle (MFC), and then prepared BMAC or hUCB-MSCs in combination with scaffolds were implanted in the MFC lesions. After propensity score matching based on sex, age, body mass index, and lesion size, 55 patients in each of the BMAC and hUCB-MSC groups were successfully matched. Second-look arthroscopic findings were assessed according to the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment (CRA) grading system and Koshino staging system. Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Short-Form 36 (SF-36), and Tegner activity scores.

RESULTS

At a mean follow-up of 33 months, clinical outcomes including IKDC, KOOS, SF-36, and Tegner activity scores were significantly improved in both groups (p < 0.001); however, there were no differences between the two groups. Second-look arthroscopy showed better healing of regenerated cartilage in the hUCB-MSC group (Grade I [4 cases, 9.1%]; Grade II [30 cases, 68.2%]; Grade III [11 cases, 22.7%]) than in the BMAC group (Grade I [1 case, 2.7%]; Grade II [20 cases, 54.1%]; Grade III [11 cases, 29.7%]; Grade IV [5 cases, 13.5%]) according to the ICRS CRA grading system (p = 0.040). There was no significant intergroup difference in terms of defect coverage based on the Koshino staging system (p = 0.057). Moreover, ICRS CRA grades at second-look arthroscopy were significantly correlated with clinical outcomes (r = - 0.337; p = 0.002).

CONCLUSION

There were no significant differences in the clinical outcomes between the two groups. Both treatments provided similar, reliable outcomes in terms of pain relief, functional scores, and quality of life at a mean follow-up of 33 months. However, hUCB-MSC implantation was more effective than BMAC augmentation for articular cartilage regeneration.

High Variability of Mesenchymal Stem Cells Obtained via Bone Marrow Aspirate Concentrate Compared With Traditional Bone Marrow Aspiration Technique

Background:

Bone marrow aspirate (BMA) is a common source for harvesting mesenchymal stem cells (MSCs), other progenitor cells, and associated cytokines and growth factors to be used in the biologic treatment of various orthopaedic pathologies. The aspirate is commonly centrifuged into a concentrated volume that can be immediately administered to a patient using commercially available kits. However, the handling and efficacy of BMA concentrate (BMAC) are still controversial.

Purpose:

To characterize BMA versus BMAC for MSC quantity, potency, and cytokine profile.

Study Design:

Controlled laboratory study.

Methods:

From 8 participants (age, 17-68 years), 30 mL of bone marrow was aspirated by a single surgeon from either the proximal humerus or distal femur and was separated into 2 equal samples. One sample was kept as BMA, and the other half was centrifuged into BMAC. The 2 samples then underwent flow cytometry for detection of MSCs, cell analysis for colony-forming units (CFUs), and cytokine profiling. A 2-tailed t test was used to detect differences between MSCs, CFUs, and cytokine density concentrations between BMA and BMAC.

Results:

The average concentration of MSCs in both BMA and BMAC was 0.001%. Average MSC events detected by flow cytometry were significantly higher in BMA versus BMAC (15.1 and 8.1, respectively; P < .045). Expanded MSCs demonstrated similar phenotypes, but CFUs were significantly increased in BMA compared with BMAC (104 vs 68 CFUs, respectively; P < .001). Total protein concentration and cytokine profiling demonstrated great variability between BMA and BMAC and between patients. Most importantly, BMAC failed to concentrate MSCs in 6 of 8 samples.

Conclusion:

There is great variability in MSC concentration, total protein concentration, and cytokine profile between BMA and BMAC.

Clinical Relevance:

When studying the clinical efficacy of BMAC, one must also evaluate the sample itself to determine the presence, concentration, and potency of MSCs if this is to be considered a cell-based therapy. Further standard operating procedures need to be investigated to ensure reproducible results and appropriate treatments.

Treatment of Full-Thickness Acetabular Chondral Flaps During Hip Arthroscopy: Bone Marrow Aspirate Concentrate Versus Microfracture

Background:

The optimal treatment strategy for patients with full-thickness chondral flaps undergoing hip arthroscopy is controversial.

Purpose:

To compare functional outcomes of patients who underwent bone marrow aspirate concentrate (BMAC) application with those of patients who underwent microfracture.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This was a retrospective case series of prospectively collected data on patients who underwent arthroscopic acetabular labral repair by 1 surgeon between June 2014 and April 2020. The inclusion criteria for this study were age ≥18 years, preoperative radiographs of the pelvis, arthroscopic acetabular labral repair, exposed subchondral bone with overlying chondral flap seen at the time of hip arthroscopy, microfracture or BMAC to address this lesion, and completed patient-reported outcome measures (PROMs) (International Hip Outcome Tool–33 [iHOT-33], Hip Outcome Score–Activities of Daily Living [HOS-ADL], Hip Outcome Score–Sports Subscale [HOS-Sport], modified Harris Hip Score [mHHS], and visual analog scale [VAS] for pain) at enrollment and 12-month follow-up. Clinical outcomes were assessed using PROM scores.

Results:

A total of 81 hips with full-thickness chondral flaps were included in this study: 50 treated with BMAC and 31 treated with microfracture. There were no significant differences between groups in age, sex, body mass index, tear size, radiographic osteoarthritis, or radiographic femoroacetabular impingement. In the BMAC cohort, all PROM scores improved significantly from preoperatively to follow-up: 41.7 to 75.6 for iHOT-33, 67.6 to 91.0 for HOS-ADL, 41.5 to 72.3 for HOS-Sport, 59.4 to 87.2 for mHHS, and 6.2 to 2.2 for VAS pain (P < .001 for all). In the microfracture cohort, the score improvements were 48.0 to 65.1 for iHOT-33 (P = .001), 80.5 to 83.3 for HOS-ADL (P = .275), 59.2 to 62.4 for HOS-Sport (P = .568), 70.4 to 78.3 for mHHS (P = .028), and 4.9 to 3.6 for VAS pain (P = .036). Regarding clinically meaningful outcomes, 77.6% of the BMAC group and 50.0% of the microfracture group met the minimal clinically important difference for iHOT-33 at the 12-month follow-up (P = .013).

Conclusion:

Patients with full-thickness chondral flaps at the time of hip arthroscopy experienced greater improvements in functional outcome scores at the 12-month follow-up when treated with BMAC as opposed to microfracture.

Combined Bone Marrow Aspirate and Platelet-Rich Plasma for Cartilage Repair: Two-Year Clinical Results

PURPOSE

To evaluate the clinical and biological outcome of combined bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) on a collagen scaffold for treating cartilage lesions in the knee.

METHODS AND MATERIALS

Ten patients (mean age 29.4 years, range 18-36) suffering from large full-thickness cartilage in the knee were treated with BMAC and PRP from January 2015 to December 2016. In a 1-step procedure autologous BMAC and PRP was seeded onto a collagen scaffold and sutured into the debrided defect. Patients were evaluated by clinical outcome scores (IKDC [International Knee Documentation Committee Subjective Knee Form], KOOS [Knee Injury and Osteoarthritis Outcome Score], and pain score using the Numeric Rating Scale [NRS]) preoperatively, after 3 months, and after 1 and 2 years. Second-look arthroscopies were performed (n = 7) with biopsies of the repair tissue for histology. All patients had magnetic resonance imaging (MRI) preoperatively, after 1 year, and after 2 to 3.5 years with MOCART (magnetic resonance observation of cartilage repair tissue) scores evaluating cartilage repair.

RESULTS

After 1 year significant improvements were found in IKDC, KOOS symptoms, KOOS ADL (Activities of Daily Living), KOOS QOL (Quality of Life), and pain at activity. At the latest follow-up significant improvements were seen in IKDC, KOOS symptoms, KOOS QOL, pain at rest, and pain at activity. MRI MOCART score for cartilage repair improved significantly from baseline to 1-year follow-up. Histomorphometry of repair tissue demonstrated a mixture of fibrous tissue (58%) and fibrocartilage (40%).

CONCLUSION

Treatment of cartilage injuries using combined BMAC and PRP improved subjective clinical outcome scores and pain scores at 1 and 2 years postoperatively. MRI and histology indicated repair tissue inferior to the native hyaline cartilage.

Efficacy and Safety of Intra-Articular Cell-Based Therapy for Osteoarthritis: Systematic Review and Network Meta-Analysis

OBJECTIVE

Osteoarthritis (OA) is a chronic joint disease characterized by degeneration of articular cartilage and secondary osteogenesis. Cell-based agents, such as mesenchymal stem cells, have turned into the most extensively explored new therapeutic agents for OA. However, evidence-based research is still lacking.

METHODS

We searched public databases up to February 2020 and only included randomized controlled trials. The outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Knee Injury and Osteoarthritis Outcome Score (KOOS), the visual analogue scale (VAS) score, and serious adverse events (SAEs). A network meta-analysis was also performed in this work.

RESULTS

We included 13 studies in the meta-analysis. The effect size showed that cell-based therapy did not significantly reduce the WOMAC score at the 6-month follow-up (standard mean difference [SMD] -3.6; 95% confidence interval [CI] -0.90 to 0.18; P = 0.1928). However, cell-based therapy significantly improved the KOOS at the 12-month follow-up (SMD 0.68; 95% CI 0.07-1.30; P = 0.0288) and relieved pain (SMD -1.05; 95% CI -1.46 to -0.64; P < 0.0001). The findings also indicated that high-dosage adipose-derived mesenchymal stem cells (ADMSCs) may be more advantageous in terms of long-term effects.

CONCLUSIONS

Cell-based therapy had a better effect on KOOS improvement and pain relief without safety concerns. However, cell-based therapy did not show a benefit in terms of the WOMAC. Allogeneic cells might have advantages compared to controls in the WOMAC and KOOS scores. The long-term effect of high-dose ADMSC treatment for OA is worthy of further study.

Osteochondral Lesions of the Talus: A Review on Talus Osteochondral Injuries, Including Osteochondritis Dissecans

This is a review on talus osteochondritis dissecans and talus osteochondral lesions. A majority of the osteochondral lesions are associated with trauma while the cause of pure osteochondritis dissecans is still much discussed with a possible cause being repetitive microtraumas associated with vascular disturbances causing subchondral bone necrosis and disability. Symptomatic nondisplaced osteochondral lesions can often be treated conservatively in children and adolescents while such treatment is less successful in adults. Surgical treatment is indicated when there is an unstable cartilage fragment. There are a large number of different operative technique options with no number one technique to be recommended. Most techniques have been presented in level II to IV studies with a low number of patients with short follow ups and few randomized comparisons exist. The actual situation in treating osteochondral lesions in the ankle is presented and discussed.

A Systematic Review of Focal Cartilage Defect Treatments in Middle-Aged Versus Younger Patients

Background:

Focal cartilage defects are often debilitating, possess limited potential for regeneration, are associated with increased risk of osteoarthritis, and are predictive for total knee arthroplasty. Cartilage repair studies typically focus on the outcome in younger patients, but a high proportion of treated patients are 40 to 60 years of age (ie, middle-aged). The reality of current clinical practice is that the ideal patient for cartilage repair is not the typical patient. Specific attention to cartilage repair outcomes in middle-aged patients is warranted.

Purpose:

To systematically review available literature on knee cartilage repair in middle-aged patients and include studies comparing results across different age groups.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic search was performed in EMBASE, MEDLINE, and the Cochrane Library database. Articles were screened for relevance and appraised for quality.

Results:

A total of 21 articles (mean Coleman Methodology Score, 64 points) were included. Two out of 3 bone marrow stimulation (BMS) studies, including 1 using the microfracture technique, revealed inferior clinical outcomes in middle-aged patients in comparison with younger patients. Nine cell-based studies were included showing inconsistent comparisons of results across age groups for autologous chondrocyte implantation (ACI). Bone marrow aspirate concentrate showed age-independent results at up to 8 years of follow-up. A negative effect of middle age was reported in 1 study for both ACI and BMS. Four out of 5 studies on bone-based resurfacing therapies (allografting and focal knee resurfacing implants [FKRIs]) showed age-independent results up to 5 years. One study in only middle-aged patients reported better clinical outcomes for FKRIs when compared with biological repairs.

Conclusion:

Included studies were heterogeneous and had low methodological quality. BMS in middle-aged patients seems to only result in short-term improvements. More research is warranted to elucidate the ameliorating effects of cell-based therapies on the aging joint homeostasis. Bone-based therapies seem to be relatively insensitive to aging and may potentially result in effective joint preservation. Age subanalyses in cohort studies, randomized clinical trials, and international registries should generate more evidence for the large but underrepresented (in terms of cartilage repair) middle-aged population in the literature.

Sheep condyle model evaluation of bone marrow cell concentrate combined with a scaffold for repair of large osteochondral defects

Aims

Minimally manipulated cells, such as autologous bone marrow concentrates (BMC), have been investigated in orthopaedics as both a primary therapeutic and augmentation to existing restoration procedures. However, the efficacy of BMC in combination with tissue engineering is still unclear. In this study, we aimed to determine whether the addition of BMC to an osteochondral scaffold is safe and can improve the repair of large osteochondral defects when compared to the scaffold alone.

Methods

The ovine femoral condyle model was used. Bone marrow was aspirated, concentrated, and used intraoperatively with a collagen/hydroxyapatite scaffold to fill the osteochondral defects (n = 6). Tissue regeneration was then assessed versus the scaffold-only group (n = 6). Histological staining of cartilage with alcian blue and safranin-O, changes in chondrogenic gene expression, microCT, peripheral quantitative CT (pQCT), and force-plate gait analyses were performed. Lymph nodes and blood were analyzed for safety.

Results

The results six months postoperatively showed that there were no significant differences in bone regrowth and mineral density between BMC-treated animals and controls. A significant upregulation of messenger RNA (mRNA) for types I and II collagens in the BMC group was observed, but there were no differences in the formation of hyaline-like cartilage between the groups. A trend towards reduced sulphated glycosaminoglycans (sGAG) breakdown was detected in the BMC group but this was not statistically significant. Functional weightbearing was not affected by the inclusion of BMC.

Conclusion

Our results indicated that the addition of BMC to scaffold is safe and has some potentially beneficial effects on osteochondral-tissue regeneration, but not on the functional endpoint of orthopaedic interest.

Cite this article: Bone Joint Res 2021;10(10):677–689.

Arthroscopic Fixation of Knee Femoral Condyle Osteochondritis Dissecans Fragment With Bone Marrow Aspirate Concentrate

This article reviews a technique for arthroscopic fixation of an osteochondritis dissecans fragment with bone marrow aspirate concentrate augmentation. This technique involves safe harvest of bone marrow arthroscopically from the intercondylar notch, proper preparation and debridement of the parent bone, reduction of the progeny osteochondritis dissecans fragment, insertion of the bone marrow aspirate concentrate, and placement of multiple headless compression screws for fixation.

Allogenic Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Are More Effective Than Bone Marrow Aspiration Concentrate for Cartilage Regeneration After High Tibial Osteotomy in Medial Unicompartmental Osteoarthritis of Knee

PURPOSE

The purpose of this study was to compare the outcome of cartilage regeneration between bone marrow aspirate concentrate (BMAC) augmentation and allogeneic human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSCs) transplantation in high tibial osteotomy (HTO) with microfracture (MFX) for medial unicompartmental osteoarthritis (OA) of the knee in the young and active patient.

METHODS

Between January 2015 and December 2019, the patients who underwent HTO and arthroscopy with MFX combined with BMAC or allogeneic hUCB-MSCs procedure for medial unicompartmental OA with kissing lesion, which was shown full-thickness cartilage defect (≥ International Cartilage Repair Society [ICRS] grade 3B) in medial femoral cartilage and medial tibial cartilage, were include in this study. Retrospectively we compared clinical outcomes, including Hospital for Special Surgery score, Knee Society Score (KSS) pain and function, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between BMAC and hUCB-MSCs group at minimum of 1-year follow-up. Also, second-look arthroscopy was performed simultaneously with removal of the plate after complete bone union. Cartilage regeneration was graded by the ICRS grading system at second-look arthroscopy. Radiological measurement including hip-knee-ankle (HKA) angle, posterior tibial slope angle, and correction angle were assessed.

RESULTS

Of 150 cases that underwent HTO with MFX combined with BMAC or allogeneic hUCB-MSCs procedure for medial unicompartmental OA, 123 cases underwent plate removal and second-look arthroscopy after a minimum of 1 year after the HTO surgery. Seventy-four cases were kissing lesion in medial femoral cartilage and medial tibial cartilage during initial HTO surgery. Finally, the BMAC group composed of 42 cases and hUCB-MSCs group composed of 32 cases were retrospectively identified in patients who had kissing lesions and second-look arthroscopies with a minimum of 1 year of follow-up. At the final follow-up of mean 18.7 months (standard deviation = 4.6 months), clinical outcomes in both groups had improved. However, there were no significant differences between the IKDC, WOMAC, or KSS pain and function scores in the 2 groups (P > .05). At second-look arthroscopy, the ICRS grade was significantly better in the hUCB-MSC group than in the BMAC group in both medial femoral and medial tibial cartilage (P = .001 for both). The average ICRS grade of the BMAC group improved from 3.9 before surgery to 2.8 after surgery. The average ICRS grade of the hUBC-MSC group improved from 3.9 before surgery to 2.0 after surgery. Radiological findings comparing postoperative HKA angle, posterior tibial slope angle, and correction angle showed no significant differences between the groups (P > .05). Therefore it was found that the postoperative correction amount did not affect the postoperative cartilage regeneration results.

CONCLUSIONS

We found that the hUCB-MSC procedure was more effective than the BMAC procedure for cartilage regeneration in medial unicompartmental knee OA even though the clinical outcomes improved regardless of which treatment was administered.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Nonoperative and Operative Soft-Tissue and Cartilage Regeneration and Orthopaedic Biologics of the Knee: An Orthoregeneration Network (ON) Foundation Review

Orthoregeneration is defined as a solution for orthopedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and optimally, provide an environment for tissue regeneration. Options include: drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electro-magnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the knee, including symptomatic osteoarthritis and chondral injuries, as well as injuries to tendon, meniscus, and ligament, including the anterior cruciate ligament. Promising and established treatment modalities include hyaluronic acid (HA) in liquid or scaffold form; platelet-rich plasma (PRP); bone marrow aspirate (BMA) comprising mesenchymal stromal cells (MSCs), hematopoietic stem cells, endothelial progenitor cells, and growth factors; connective tissue progenitor cells (CTPs) including adipose-derived mesenchymal stem cells (AD-MSCs) and tendon-derived stem cells (TDSCs); matrix cell-based therapy including autologous chondrocytes or allograft; vitamin D; and fibrin clot. Future investigations should standardize solution preparations, because inconsistent results reported may be due to heterogeneity of HA, PRP, BMAC, or MSC preparations and regimens, which may inhibit meaningful comparison between studies to determine the true efficacy and safety for each treatment.

Comparison of Bone Marrow Aspirate Concentrate and Allogenic Human Umbilical Cord Blood Derived Mesenchymal Stem Cell Implantation on Chondral Defect of Knee: Assessment of Clinical and Magnetic Resonance Imaging Outcomes at 2-Year Follow-Up

Biological repair of cartilage lesions remains a significant clinical challenge. A wide variety of methods involving mesenchymal stem cells (MSCs) have been introduced. Because of the limitation of the results, most of the treatment methods have not yet been approved by the Food and Drug Administration (FDA). However, bone marrow aspirate concentrate (BMAC) and human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) implantation were approved by Korea FDA. The aim of this study was to evaluate clinical and magnetic resonance imaging (MRI) outcomes after two different types of MSCs implantation in knee osteoarthritis. Fifty-two patients (52 knees) who underwent cartilage repair surgery using the BMAC (25 knees) and hUCB-MSCs (27 knees) were retrospectively evaluated for 2 years after surgery. Clinical outcomes were evaluated according to the score of visual analogue scale (VAS), the International Knee Documentation Committee (IKDC) subjective, and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Cartilage repair was assessed according to the modified Magnetic Resonance Observation of Cartilage Repair Tissue (M-MOCART) score and the International Cartilage Repair Society (ICRS) cartilage repair scoring system. At 2-year follow-up, clinical outcomes including VAS, IKDC, and KOOS significantly improved (P < 0.05) in both groups; however, there were no differences between two groups. There was no significant difference in M-MOCART [1-year (P = 0.261), 2-year (P = 0.351)] and ICRS repair score (P = 0.655) between two groups. Both groups showed satisfactory clinical and MRI outcomes. Implantation of MSCs from BMAC or hUCB-MSCs is safe and effective for repairing cartilage lesion. However, large cases and a well-controlled prospective design with long-term follow-up studies are needed.

Ultrapurified Alginate Gel Containing Bone Marrow Aspirate Concentrate Enhances Cartilage and Bone Regeneration on Osteochondral Defects in a Rabbit Model

BACKGROUND

Ultrapurified alginate (UPAL) gel implantation has been demonstrated as effective in cartilage repair for osteochondral defects; however, cell transplantation within UPAL gels would be required to treat larger defects.

HYPOTHESIS

The combination of UPAL gel and bone marrow aspirate concentrate (BMAC) would enhance cartilage repair and subchondral bone repair for large osteochondral defects.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 104 osteochondral defects (1 defect per knee) of 52 rabbits were randomly divided into 4 groups (26 defects per group): defects without any treatment (Defect group), defects treated using UPAL gel alone (UPAL group), defects treated using UPAL gel containing allogenic bone marrow mesenchymal stromal cells (UPAL-MSC group), and defects treated using UPAL gel containing BMAC (UPAL-BMAC group). At 4 and 16 weeks postoperatively, macroscopic and histologic evaluations and measurements of repaired subchondral bone volumes of reparative tissues were performed. Collagen orientation and mechanical properties of the reparative tissue were assessed at 16 weeks.

RESULTS

The defects in the UPAL-BMAC group were repaired with hyaline-like cartilage with well-organized collagen structures. The histologic scores at 4 weeks were significantly higher in the UPAL-BMAC group (16.9 ± 2.0) than in the Defect group (4.7 ± 1.9; P < .05), the UPAL group (10.0 ± 3.3; P < .05), and the UPAL-MSC group (12.2 ± 2.9; P < .05). At 16 weeks, the score in the UPAL-BMAC group (24.4 ± 1.7) was significantly higher than those in the Defect group (9.0 ± 3.7; P < .05), the UPAL group (14.2 ± 3.9; P < .05), and the UPAL-MSC group (16.3 ± 3.6; P < .05). At 4 and 16 weeks, the macroscopic evaluations were significantly superior in the UPAL-BMAC group compared with the other groups, and the values of repaired subchondral bone volumes in the UPAL-BMAC group were significantly higher than those in the Defect and UPAL groups. The mechanical properties of the reparative tissues were significantly better in the UPAL-BMAC group than in the other groups.

CONCLUSION

The implantation of UPAL gel containing BMAC-enhanced hyaline-like cartilage repair and subchondral bone repair of osteochondral defects in a rabbit knee model.

CLINICAL RELEVANCE

These data support the potential clinical application of 1-step treatment for large osteochondral defects using biomaterial implantation with cell transplantation.

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.

Treatment of infected tibial non-unions using a BMAC and S53P4 BAG combination for reconstruction of segmental bone defects: A clinical case series

INTRODUCTION

Treatment of infected non-unions of the tibia is a challenging problem. The cornerstones of optimal infected non-union treatment consist of extensive debridement, fracture fixation, antimicrobial therapy and creation of an optimal local biological bone healing environment. The combination of S53P4 bioactive glass (BAG), as osteostimulative antibacterial bone graft substitute, and bone marrow aspirate concentrate (BMAC) for the implantation of mesenchymal stem cells and growth factors might be a promising combination. In this paper, preliminary results of a new treatment algorithm for infected non-unions of the tibia is presented.

METHODS

In this retrospective case series patients with infected non-unions of the tibia are treated according to a new treatment algorithm. Patients are treated with extensive debridement surgery, replacement of the osteosynthesis and implantation of S53P4 BAG and BMAC in a one-stage or two-stage procedure based on non-union severity. Subsequently patients are treated with culture based antibiotic therapy and followed until union and infection eradication.

RESULTS

Five patients with an infected non-union were treated, mean age was 55, average NUSS-score was 44 and the average segmental bone defect was 4.6cm. One patient was treated in a one-stage procedure and four patients in a two-stage induced membrane-, or "Masquelet"-procedure. On average, 23 ml S53P4 BAG and 6.2 ml BMAC was implanted. The mean follow-up period was 13.6 months and at the end of follow-up all patients had clinical consolidation with an average RUST-score of 7.8 and complete eradication of infection.

DISCUSSION

These early data on the combined implantation of S53P4 BAG and BMAC in treatment of infected non-unions shows promising results. These fracture healing results and eradication rates resulted in promising functional recovery of the patients. To substantiate these results, larger and higher quality studies should be performed.

Orthobiologics in the treatment of hip disorders

Orthobiologics are biological materials that are intended for the regeneration or healing of bone, cartilage and soft tissues. In this review we discuss the use of orthobiologics for hip disorders providing an update. The orthobiologics included in this article are hyaluronic acid, platelet rich plasma, bone marrow, adipose tissue and expanded mesenchymal stem cells. We explain the concepts and definitions of each orthobiological product, and the literature regarding its use in the hip joint. The paucity of guidelines for the production and characterization of the biological products leads to uneven results across the literature. Each biologic therapy has indications and benefits; however, noteworthy are the characterization of the orthobiologics, the application method and outcome analysis for further improvement of each technique.

Bone marrow aspirate concentration provided better results in cartilage regeneration to microfracture in knee of osteoarthritic patients

PURPOSE

To determine whether microfracture with bone marrow aspirate concentrate (BMAC) improves functional outcome and cartilage regeneration better than microfracture alone in patients undergoing high tibial osteotomy (HTO) for medial unicompartmental osteoarthritis (OA).

METHODS

Among 436 patients treated with HTO for medial unicompartmental OA with varus deformity between 2010 and 2016, clinical outcomes were retrospectively compared between the microfracture alone group (group I, 43 cases) and microfracture with BMAC augmentation group (group II, 48 cases). Of these, 64 patients underwent a second-look arthroscopic assessment. Clinical outcomes were compared based on the Knee Society Score (KSS), International Knee Documentation Committee (IKDC) subjective score, and Western Ontario and McMaster Universities Arthritis Index (WOMAC). Cartilage regeneration was assessed according to Koshino's staging system and the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment (CRA) grading system.

RESULTS

At the last follow-up, there were no significant intergroup differences in terms of KSS for pain and function (p > 0.05). Moreover, WOMAC scores were similar between the two groups (p > 0.05). Regarding second-look arthroscopy findings, according to Koshino's staging system, there was no significant intergroup difference in terms of defect coverage (p = 0.187). However, group II showed a significantly better mean CRA score than group I (p = 0.035).

CONCLUSION

There were no significant differences in clinical outcomes and cartilage regeneration between the groups. However, the CRA score was significantly higher with BMAC augmentation and microfracture than microfracture alone. Therefore, BMAC augmentation had a synergistic effect for a better cartilage regeneration, although studies with a longer follow-up might help to confirm whether microfracture with BMAC augmentation would ensure better clinical outcomes than microfracture alone for the treatment of knee OA.

Arthroscopic Autologous Chondrocyte Bone Grafting of a Lateral Tibial Plateau Chondral Defect

Tibial plateau chondral defects can be difficult to diagnose and treat. Although grafting of femoral and patella chondral defects has become relatively commonplace, the tibial plateau offers unique challenges for some of the grafting techniques used in these locations, mostly because of limitations with exposure even in an open approach. Arthroscopic surgery makes treatment of these lesions more feasible, as it affords better access and visualization of tibial defects. The purpose of this article is to describe the arthroscopic management of a lateral tibial plateau chondral defect via autologous chondrocyte bone grafting. The technique consists of harvest of autologous cartilage from the intercondylar notch and repair of the tibial plateau defect with a slurry of autologous chondrocytes and bone marrow aspirate concentrate. In addition, CO₂ is used as a medium to distend the joint in a tight compartment to keep the chondral defect dry. This technique is technically simple and does not require an extensive open technique or an expensive osteochondral allograft. It also avoids the staged management required in other types of autologous chondrocyte implantation, which require cartilage biopsy to produce a final product for implantation.

Managing Chondral Lesions: A Literature Review and Evidence-Based Clinical Guidelines

BACKGROUND

Articular cartilage lesions are becoming increasingly common. Optimum diagnosis and management of chondral defects cause a lot of dilemma. A number of surgical methods have been reported in the literature for treating focal cartilage defects. There is a lack of consensus on the most effective management strategy, with newer surgical and cell-based treatments being advocated regularly.

STUDY DESIGN AND METHODS

A clinical review is constructed by appraising the published literature about clinical evaluation and diagnostic modalities for articular cartilage defects and subsequent surgical procedures, management strategies employed for such lesions. Prominent available databases (PUBMED, EMBASE, Cochrane) were also searched for trials comparing functional outcomes following cartilage procedures. Synthesis of a practical management guideline is then attempted based on the evidence assessed.

RESULTS

Systematic examination and optimal use of diagnostic imaging are an important facet of cartilage defect management. Patient and lesion factors greatly influence the outcome of cartilage procedures and must be considered while planning management. Smaller lesions < 2 cm² respond well to all treatment modalities. Autologous osteochondral transplants (OATs) are effective in high activity individuals with intermediate lesions. For larger lesions > 4 cm², newer generation autologous chondrocyte implantation (ACI) has shown promising and durable results. Stem cells with scaffolds may provide an alternate option. Orthobiologics are a useful adjunct to the surgical procedures, but need further evaluation.

CONCLUSIONS

Most treatment modalities have their role in appropriate cases and management needs to be individualized for patients. The search for the perfect cartilage restoration procedure continues.

Small Cartilage Defect Management

Cartilage defects in the knee are common resulting in significant pain and morbidity over time. These defects can arise in isolation or concurrently with other associated injuries to the knee. The treatment of small (< 2-3 cm²) cartilage deficiencies has changed as our basic science knowledge of tissue healing has improved. Advancements have led to the development of new and more effective treatment modalities. It is important to address any associated knee injuries and limb malalignment. Surgical options are considered when nonoperative treatment fails. The specific procedure depends on individual patient characteristics, lesion size, and location. Debridement/chondroplasty, microfracture, marrow stimulation plus techniques, fixation of unstable osteochondral fragments, osteochondral autograft transfer, and osteochondral allograft transplantation, all have roles in the treatment of small cartilage defects.