Clinical outcomes of mesenchymal stem cell injection with arthroscopic treatment in older patients with osteochondral lesions of the talus

Adipose-derived stem cells applied to ankle pathologies: a systematic review

The purpose of this systematic review was to analyze the current use of adipose-derived mesenchymal stem cells (ADMSCs) and present the available evidence on their therapeutic potential in the treatment of ankle orthopedic issues, evaluating the applications and results. A literature search of PubMed, Google Scholar, EMBASE and Cochrane Library database was performed. The review was conducted following PRISMA guidelines. Risk of bias assessment was conducted through the Methodological Index for Non-Randomized Studies (MINORS) criteria. Initial search results yielded 4348 articles. A total of 8 articles were included in the review process. No clinical evidence has demonstrated the effectiveness of one isolation method over the other, but nonenzymatic mechanical method has more advantages. In all studies included significant clinical outcomes improvement were recorded in patients affected by osteochondral lesion and osteoarthritis of ankle. All studies performed a concomitant procedure. No serious complications were reported. ADMSC injection, especially through the nonenzymatic mechanical methods, looks to be simple and promising treatment for osteochondral lesions and osteoarthritis of the ankle, with no severe complications. The current scarcity of studies and their low-quality level preclude definitive conclusions presently. LEVEL OF EVIDENCE: III.

Full-thickness osteochondral defect repair using a biodegradable bilayered scaffold of porous zinc and chondroitin sulfate hydrogel

The regeneration of osteochondral tissue necessitates the re-establishment of a gradient owing to the unique characteristics and healing potential of the chondral and osseous phases. As the self-healing capacity of hyaline cartilage is limited, timely mechanical support during neo-cartilage formation is crucial to achieving optimal repair efficacy. In this study, we devised a biodegradable bilayered scaffold, comprising chondroitin sulfate (CS) hydrogel to regenerate chondral tissue and a porous pure zinc (Zn) scaffold for regeneration of the underlying bone as mechanical support for the cartilage layer. The photocured CS hydrogel possessed a compressive strength of 82 kPa, while the porous pure Zn scaffold exhibited a yield strength of 11 MPa and a stiffness of 0.8 GPa. Such mechanical properties are similar to values reported for cancellous bone. In vitro biological experiments demonstrated that the bilayered scaffold displayed favorable cytocompatibility and promoted chondrogenic and osteogenic differentiation of bone marrow stem cells. Upon implantation, the scaffold facilitated the simultaneous regeneration of bone and cartilage tissue in a porcine model, resulting in (i) a smoother cartilage surface, (ii) more hyaline-like cartilage, and (iii) a superior integration into the adjacent host tissue. Our bilayered scaffold exhibits significant potential for clinical application in osteochondral regeneration.

Exosomal miR-4645-5p from hypoxic bone marrow mesenchymal stem cells facilitates diabetic wound healing by restoring keratinocyte autophagy

Background

Refractory diabetic wounds are a common occurrence in patients with diabetes and epidermis-specific macroautophagy/autophagy impairment has been implicated in their pathogenesis. Therefore, identifying and developing treatment strategies capable of normalizing epidermis-specific macroautophagy/autophagy could facilitate diabetic wound healing. The study aims to investigate the potential of bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) from hypoxic conditions as a treatment to normalize epidermis-specific autophagy for diabetic wound healing.

Methods

We compared the effects of bone marrow mesenchymal stem cell (BMSC)-sourced exosomes (BMSC-Exos) from hypoxic conditions to those of BMSC in normoxic conditions (noBMSC-Exos). Our studies involved morphometric assessment of the exosomes, identification of the microRNA (miRNA) responsible for the effects, evaluation of keratinocyte functions and examination of effects of the exosomes on several molecules involved in the autophagy pathway such as microtubule-associated protein 1 light chain 3 beta, beclin 1, sequestosome 1, autophagy-related 5 and autophagy-related 5. The experiments used human BMSCs from the American Type Culture Collection, an in vivo mouse model of diabetes (db/db) to assess wound healing, as well as the human keratinocyte HaCaT cell line. In the methodology, the authors utilized an array of approaches that included electron microscopy, small interfering RNA (siRNA) studies, RNA in situ hybridization, quantitative real-time reverse transcription PCR (qRT-PCR), the isolation, sequencing and differential expression of miRNAs, as well as the use of miR-4645-5p-specific knockdown with an inhibitor.

Results

Hypoxia affected the release of exosomes from hypoxic BMSCs (hy-BMSCs) and influenced the size and morphology of the exosomes. Moreover, hyBMSC-Exo treatment markedly improved keratinocyte function, including keratinocyte autophagy, proliferation and migration. miRNA microarray and bioinformatics analysis showed that the target genes of the differentially expressed miRNAs were mainly enriched in 'autophagy' and 'process utilizing autophagic mechanism' in the 'biological process' category and miR-4645-5p as a major contributor to the pro-autophagy effect of hyBMSC-Exos. Moreover, mitogen-activated protein kinase-activated protein kinase 2 (MAPKAPK2) was identified as a potential target of exosomal miR-4645-5p; this was confirmed using a dual luciferase assay. Exosomal miR-4645-5p mediates the inactivation of the MAPKAPK2-induced AKT kinase group (comprising AKT1, AKT2, and AKT3), which in turn suppresses AKT-mTORC1 signaling, thereby facilitating miR-4645-5p-mediated autophagy.

Conclusions

Overall, the results of this study showed that hyBMSC-Exo-mediated transfer of miR-4645-5p inactivated MAPKAPK2-induced AKT-mTORC1 signaling in keratinocytes, which activated keratinocyte autophagy, proliferation and migration, resulting in diabetic wound healing in mice. Collectively, the findings could aid in the development of a novel therapeutic strategy for diabetic wounds.

Limited evidence of adjuvant biologics with bone marrow stimulation for the treatment of osteochondral lesion of the talus: a systematic review

PURPOSE

To evaluate the complication rates, continuous functional outcome scores, and return to play data following bone marrow stimulation (BMS) versus biologics ± BMS for the treatment of osteochondral lesion of the talus (OLT).

METHODS

A systematic review was performed. The PubMed and Embase databases were searched using specific search terms and eligibility criteria according to the PRISMA guidelines. The level of evidence was assessed using published criteria by The Journal of Bone & Joint Surgery, and the quality of evidence using the Modified Coleman Methodology Score. Continuous variables were presented as mean ± standard deviation and categorical variables as frequencies (percentages).

RESULTS

BMS versus BMS + hyaluronic acid (HA): no complications in either treatment arm were reported. The mean American Orthopaedic Foot and Ankle Society score was 43.5 to 67.3 points and 44.0 to 72.4 points, respectively. The mean 10 mm Visual Analogue Scale pain score was 7.7 to 3.8 points and 7.5 to 2.5 points, respectively. BMS versus BMS + concentrated bone marrow aspirate (CBMA): the pooled overall complication rate was 17/64 (26.6%) versus 11/71 (15.5%), respectively (non-significant). The pool revision rate was 15/64 (23.4%) versus 6/71 (8.5%), respectively (p = 0.016). There has been a notable poor reporting of complication rates for the use of ADSC and PRP as adjuvant biological therapies to BMS for the treatment of OLT.

CONCLUSION

There was an overall limited comparative clinical evidence of adjuvant biologics with BMS versus BMS alone for the treatment of OLT. BMS + HA and BMS + CBMA can provide superior outcomes, albeit the currently limited evidence. Further studies are warranted to establish the true clinical superiority of the various biologics ± BMS versus BMS alone. These studies must also compare the various biologics against one another to determine, if any, the optimal biologic for OLT. Clinicians should counsel patients accordingly on these findings as required.

LEVEL OF EVIDENCE

Level III.

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

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

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

Background

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

Methods

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

Results

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

Conclusion

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

Research progress in the use of mesenchymal stem cells and their derived exosomes in the treatment of osteoarthritis

Osteoarthritis (OA), as a common orthopedic disease with cartilage injury as its main pathological feature, has a complex pathogenesis and existing medical technology remains unable to reverse the progress of cartilage degeneration caused thereby. In recent years, mesenchymal stem cells (MSCs) and their secreted exosomes have become a focus of research into cartilage regeneration. MSCs have the potential to differentiate into a variety of cells. Under specific conditions, they can be promoted to differentiate into chondrocytes and maintain the function and stability of chondrocytes. Exosomes secreted by MSCs, as an intercellular messenger, can treat OA in a variety of ways through bioactive factors carried therewith, such as protein, lipid, mRNA, and miRNA. This study reviewed the application of MSCs and their exosomes from different sources in the prevention of OA, which provides a new idea for the treatment of OA.

Nonoperative and Operative Soft-Tissue and Cartilage Regeneration and Orthopaedic Biologics of the Foot and Ankle: An Orthoregeneration Network Foundation Review

Orthoregeneration is defined as a solution for orthopaedic 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 electromagnetic 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 foot and ankle (including acute traumatic injuries and fractures, tumor, infection, osteochondral lesions, arthritis, and tendinopathy) and procedures, including osteotomy or fusion. Promising and established treatment modalities include 1) bone-based therapies (such as cancellous or cortical autograft from the iliac crest, proximal tibia, and/or calcaneus, fresh-frozen or freeze-dried cortical or cancellous allograft, including demineralized bone matrix putty or powder combined with growth factors, and synthetic bone graft substitutes, such as calcium sulfate, calcium phosphate, tricalcium phosphate, bioactive glasses (often in combination with bone marrow aspirate), and polymers; proteins such as bone morphogenic proteins; and platelet-derived growth factors; 2) cartilage-based therapies such as debridement, bone marrow stimulation (such as microfracture or drilling), scaffold-based techniques (such as autologous chondrocyte implantation [ACI] and matrix-induced ACI, autologous matrix-induced chondrogenesis, matrix-associated stem cell transplantation, particulated juvenile cartilage allograft transplantation, and minced local cartilage cells mixed with fibrin and platelet rich plasma [PRP]); and 3) blood, cell-based, and injectable therapies such as PRP, platelet-poor plasma biomatrix loaded with mesenchymal stromal cells, concentrated bone marrow aspirate, hyaluronic acid, and stem or stromal cell therapy, including mesenchymal stem cell allografts, and adipose tissue-derived stem cells, and micronized adipose tissue injections. LEVEL OF EVIDENCE: Level V, expert opinion.

An optimized method for obtaining clinical-grade specific cell subpopulations from human umbilical cord-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) are heterogeneous populations with broad application prospects in cell therapy, and using specific subpopulations of MSCs can enhance their particular capability under certain conditions and achieve better therapeutic effects. However, no studies have reported how to obtain high‐quality specific MSC subpopulations in vitro culture. Here, for the first time, we established a general operation process for obtaining high‐quality clinical‐grade cell subpopulations from human umbilical cord MSCs (hUC‐MSCs) based on particular markers. We used the MSC‐CD106⁺ subpopulations, whose biological function has been well documented, as an example to explore and optimize the crucial links of primary preparation, pre‐treatment, antibody incubation, flow sorting, quality and function test. After comprehensively evaluating the quality and function of the acquired MSC‐CD106⁺ subpopulations, including in vitro cell viability, apoptosis, proliferation, marker stability, adhesion ability, migration ability, tubule formation ability, immunomodulatory function and in vivo wound healing ability and proangiogenic activity, we defined an important pre‐treatment scheme which might effectively improve the therapeutic efficiency of MSC‐CD106⁺ subpopulations in two critical clinical application scenarios—direct injection after cell sorting and post‐culture injection into bodies. Based on the above, we tried to establish a general five‐step operation procedure for acquiring high‐quality clinical‐grade MSC subpopulations based on specific markers, which cannot only improve their enrichment efficiency and the reliability of preclinical studies, but also provide valuable methodological guidance for the rapid clinical transformation of specific MSC subpopulations.

Outcomes of Bone Marrow Stimulation for Secondary Osteochondral Lesions of the Talus Equal Outcomes for Primary Lesions

OBJECTIVE

To compare clinical, sports, work, and radiological outcomes between primary and secondary osteochondral lesions of the talus (OLTs; <15 mm) treated with arthroscopic bone marrow stimulation (BMS).

DESIGN

Secondary OLTs were matched to primary OLTs in a 1:2 ratio to assess the primary outcome measure-the Numeric Rating Scale (NRS) during activities. Secondary outcomes included the pre- and 1-year postoperative NRS at rest, American Orthopaedic Foot and Ankle Society score, Foot and Ankle Outcome Score subscales, and the EQ-5D general health questionnaire. The rates and time to return to work and sports were collected. Radiological examinations were performed preoperatively and at final follow-up using computed tomography (CT).

RESULTS

After matching, 22 and 12 patients with small (<15 mm) OLTs were included in the primary and secondary groups, respectively. The NRS during activities was not different between primary cases (median: 2, interquartile range [IQR]: 1-4.5) and secondary cases (median: 3, IQR: 1-4), P = 0.5. Both groups showed a significant difference between all pre- and postoperative clinical outcome scores, but no significant difference between BMS groups postoperatively. The return to sport rate was 90% for primary cases and 83% for secondary cases (P = 0.6). All patients returned to work. Lesion filling on CT was complete (67% to 100%) in 59% of primary cases and 67% of secondary cases (P = 0.6).

CONCLUSION

No differences in outcomes were observed between arthroscopic bone marrow stimulation in primary and secondary OLTs at 1-year follow-up. Repeat BMS may therefore be a viable treatment option for failed OLTs in the short term.

Augmented Microfracture Technique Versus Microfracture in Talar Cartilage Restoration: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to compare the efficacy and safety between the microfracture (MFx) and augmented microfracture (MFx+) techniques for articular cartilage defects of the talus (OLTs). PubMed and EMBASE were searched from January 1950 to October 2020. Only randomized controlled trials, quasi-randomized controlled trials, and observational studies (retrospective and prospective) applying MFx and MFx+ techniques to treat talar cartilage defects were selected. Ten trials with 492 patients were included. There was significant difference in final American Orthopaedic Foot & Ankle Society score (AOFAS) (mean difference [MD] = 7.07; 95% confidence interval [CI], 3.70-10.44; p < .01), AOFAS change (MD = 7.97; 95% CI, 4.27-11.66; p < .01), visual analog scale (VAS) change score (MD = 0.44; 95% CI, 0.29-0.59; p < .01), Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score (MD = 12.51; 95% CI, 7.16-17.86; p < .01), complication (RR = 0.33; 95% CI, 0.16-0.69; p < .01), and revision (Relative risk = 0.34; 95% CI, 0.15-0.77; p < .05), between the MFx and MFx+ groups. No significant difference was observed for final VAS pain score (MD = -0.53; 95% CI, -1.2 to 1.05; p = .13) and Tegner scale (MD = 0.31; 95% CI, -1.05 to 1.66; p = .66) in either group. Our results suggest that augmented microfracture is superior to microfracture alone in the treatment of talar OLTs based on the AOFAS, MOCART, VAS score, complication rate, and revision ratio. Therefore, microfracture with augmentation should be considered as a treatment for OLTs of talus. However, more randomized trials are still required to determine the long-term superiority of MFx+.

Cell Sources for Cartilage Repair-Biological and Clinical Perspective

Cell-based therapy represents a promising treatment strategy for cartilage defects. Alone or in combination with scaffolds/biological signals, these strategies open many new avenues for cartilage tissue engineering. However, the choice of the optimal cell source is not that straightforward. Currently, various types of differentiated cells (articular and nasal chondrocytes) and stem cells (mesenchymal stem cells, induced pluripotent stem cells) are being researched to objectively assess their merits and disadvantages with respect to the ability to repair damaged articular cartilage. In this paper, we focus on the different cell types used in cartilage treatment, first from a biological scientist’s perspective and then from a clinician’s standpoint. We compare and analyze the advantages and disadvantages of these cell types and offer a potential outlook for future research and clinical application.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

II, prospective cohort study.

Osteochondral Lesions of the Talus: An Individualized Treatment Paradigm from the Amsterdam Perspective

Osteochondral lesions of the talus (OLTs) are characterized by damage to the articular cartilage of the talus and its underlying subchondral bone. Up to 75% of OLTs are caused by trauma, such as an ankle sprain or fracture. Physical examination and imaging are crucial for diagnosis and characterization of an OLT. No superior treatment for OLTs exists. It is paramount that an evidence-based personalized treatment approach is applied to patients with OLTs because lesion and patient characteristics guide treatment. This current concepts review covers clinical and preclinical evidence on OLT etiology, presentation, diagnosis, and treatment, all based on the Amsterdam perspective.

Emerging Biological Treatment Methods for Ankle Joint and Soft Tissue Conditions: Clinical Applications as Alternative or Adjuvant

In the past 2 decades, there has been a rapid expansion of clinical studies investigating the safety and efficacy of biological treatment methods for a wide range of diseases. These biological treatment methods increasingly are used in clinical practice based on limited available evidence. This article provides an overview of evidence on biological treatment methods for foot and ankle pathologies, including ankle osteoarthritis, osteochondral lesions of the talus, and Achilles tendinopathy.

Demographic Predictors of Concomitant Osteochondral Lesion of the Talus in Patients With Chronic Lateral Ankle Instability

Background:

Osteochondral lesion of the talus (OLT) is commonly found as a concomitant pathologic lesion in a large proportion of patients with chronic lateral ankle instability (CLAI). This study investigated which characteristics in a patient with CLAI increase the risk for OLT.

Methods:

Three hundred sixty-four patients who underwent a modified Broström operation for their CLAI were reviewed retrospectively. The characteristics of each patient and variables associated with OLTs were investigated. Statistical analyses were performed to determine the effect of each potential predictor on the incidence of OLT, and to evaluate the associations between the patient characteristics and variables associated with OLTs.

Results:

Patients with OLTs were more frequently female (female vs male: 63.1% vs 43.9%, P = .003). In addition, the lesion sizes were larger in female patients (female vs male: 113.9 ± 24.9 mm² vs 100.7 ± 18.0 mm², P = .002), and medial lesions were more common in female patients (female vs male; 93.3% vs 81.8%, P = .036). The lesion sizes were larger in patients with a wider talar tilt angle (P < .001), and patients with a medial OLT showed a wider talar tilt angle (12.0 ± 2.0 degrees vs 10.3 ± 2.2 degrees, P = .002).

Conclusion:

In this CLAI patient cohort, we found female patients to be at greater risk for OLTs than male patients. Furthermore, CLAI female patients with concomitant OLT had on average a larger lesion size, more frequent OLT medial position, and were associated with wider talar tilt angles, suggesting that females had more intrinsic ankle instability than males.

Level of Evidence:

Level IV, retrospective case series.

Biologic therapies for foot and ankle injuries

Introduction: The use of orthobiologics as supplemental treatment for foot and ankle pathologies have increased in the past decades. They have been used to improve the healing of bone and soft tissue injuries. There have been several studies that examined the use of biologics for knee and hip pathologies but the foot and ankle construct has unique features that must be considered.Areas covered: The biologics for foot and ankle injuries that are covered in this review are platelet-rich plasma (PRP), stem cells, growth factors, hyaluronic acid, bone grafts, bone substitutes, and scaffolds. These modalities are used in the treatment of pathologies related to tendon and soft tissue as well as cartilage.Expert opinion: The utilization of biological adjuncts for improved repair and regeneration of ankle injuries represents a promising future in our efforts to address difficult clinical problems. The application of concentrated bone marrow and PRP each represents the most widely studied and commonly used injection therapies with early clinical studies demonstrating promising results, research is also being done using other potential therapies such as stem cells and growth factors; further investigation and outcome data are still needed.

Arthroscopic microfracture with atelocollagen augmentation for osteochondral lesion of the talus: a multicenter randomized controlled trial

BACKGROUND

We aimed to evaluate whether arthroscopic microfracture with atelocollagen augmentation could improve the clinical outcomes and quality of regenerated cartilage in patients with osteochondral lesion of the talus (OLT). We hypothesized that the clinical outcomes and quality of the regenerated cartilage would be superior in patients undergoing arthroscopic microfracture with atelocollagen augmentation compared to those undergoing arthroscopic microfracture alone.

METHODS

In this multicenter, randomized controlled trial, 60 patients were randomly allocated to two groups: arthroscopic microfracture with atelocollagen augmentation (group 1, n = 31) and arthroscopic microfracture alone (group 2, n = 29). Mean 100-mm visual analog scale (VAS), Hannover scoring system (HSS), and American Orthopedic Foot and Ankle Society (AOFAS) scores were assessed 2 years postoperatively and compared between the groups. The quality of the regenerated cartilage was assessed according to the Magnetic Resonance Observation of CArtilage Repair Tissue (MOCART) score based on magnetic resonance imaging.

RESULTS

Forty-six patients (22 in group 1, 23 in group 2) completed the 2-year follow-up. The quality of the regenerated cartilage assessed based on the MOCART score was significantly superior in group 1 compared to group 2 (64.49 ± 18.27 vs 53.01 ± 12.14, p = 0.018). Clinical outcomes in terms of 100-mm VAS (17.25 ± 20.31 vs 19.37 ± 18.58, p = 0.72), HSS (93.09 ± 13.64 vs 86.09 ± 13.36, p = 0.14), and AOFAS (91.23 ± 8.62 vs 86.91 ± 10.68, p = 0.09) scores were superior in group 1 compared to group 2, but the differences were not statistically significant. Both groups showed significant improvements in clinical outcomes compared with the preoperative values.

CONCLUSION

The quality of the regenerated cartilage was superior after arthroscopic microfracture with atelocollagen augmentation compared to that after microfracture alone in patients with OLT. Clinical outcomes assessed 2 years postoperatively were superior in patients who underwent arthroscopic microfracture with atelocollagen augmentation compared to those who underwent arthroscopic microfracture alone, although the differences were not statistically significant. A long-term study of the cohort is required to confirm these findings.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT02519881 ), August 11, 2015.

Micro-fragmented stromal-vascular fraction plus microfractures provides better clinical results than microfractures alone in symptomatic focal chondral lesions of the knee

PURPOSE

To evaluate clinical outcomes over a 1-year period in patients affected by symptomatic focal chondral lesions of the knee treated with micro-fragmented stromal-vascular fraction plus microfractures compared to microfractures alone.

METHODS

Two groups of 20 patients were arthroscopically treated with microfractures for a symptomatic focal chondral defect of the knee. At the end of surgery, in the experimental group, micro-fragmented stromal-vascular fraction was injected into the joint. Primary end point was WOMAC score at 12 months. Secondary end points were any adverse events, Oxford Knee Score, EQ-5D score, VAS for pain, analgesic and anti-inflammatory consumption.

RESULTS

All the patients were evaluated at 12-month follow-up. No adverse reactions were noted. Analgesic and anti-inflammatory consumption was similar in both groups. At 1-month follow-up, no differences were noted between groups when compared to pre-operative scores. At 3-month follow-up, patients in both groups improved from the baseline in all variables. Significantly lower VAS scores were found in the experimental group (4.2 ± 3.2 vs. 5.9 ± 1.7, p = 0.04). At 6- and 12-month follow-ups, patients in the experimental group scored better in all outcomes with a moderate effect size; in particular, better WOMAC scores were obtained at 12 months, achieving the primary end-point of the study (17.7 ± 11.1 vs. 25.5 ± 12.7; p = 0.03).

CONCLUSIONS

Injection of micro-fragmented stromal-vascular fraction is safe and, when associated with microfractures, is more effective in clinical terms than microfractures alone in patients affected by symptomatic focal chondral lesions of the knee. Results of the current study provide information that could help physicians to improve their counseling for patients concerning ADMSCs.

LEVEL OF EVIDENCE

Level 1-therapeutic study.

Minimally Invasive Treatment of Chronic Ankle Instability: a Comprehensive Review

PURPOSE OF REVIEW

Chronic ankle pain is a prevalent and significant cause of chronic pain. While the definition of chronic ankle pain is heterogeneous and poorly defined in the literature, systematic reviews and meta-analyses have estimated this condition to be a prevalent and debilitating source of chronic pain. The most identifiable and prominent cause of chronic ankle pain is chronic ankle instability (CAI), a condition defined by instability of the ankle-joint complex. It is a common consequence of lateral ankle sprains or ligamentous injuries and can be described as a failure of the lateral ankle joint complex after an acute, or recurring, ankle injury. The objective of this manuscript is to provide a comprehensive review of CAI diagnosis and our current understanding of minimally invasive treatment options.

RECENT FINDINGS

First-line treatment is conservative management, some of which includes neuromuscular rehabilitation, balance training, nonsteroidal anti-inflammatory drugs (NSAIDs), manual mobilization, ice therapy, and compression. While conservative management is effective, additional treatments for those who fail conservative management, or who seek alternative options also have been explored. Recent advances and modern techniques have expanded available treatment options, many of which are becoming less invasive, and have shown improving functionality, recovery, and patient satisfaction. Minimally invasive treatments highlighted in this review include: arthroscopic surgery, steroid injections, plasma-rich plasma injections, hyaluronic acid (HA) injections, medicinal signaling cell injections, radiofrequency therapies, and shockwave therapies. This review will discuss some of these current treatments for minimally invasive treatment of CAI, as well as suggest novel treatments for clinical trials and further investigation.

Online Direct-to-Consumer Advertising of Stem Cell Therapy for Musculoskeletal Injury and Disease: Misinformation and Violation of Ethical and Legal Advertising Parameters

BACKGROUND

There has been a recent surge in health-care providers offering stem cell therapy (SCT) to patients with musculoskeletal disease. The purpose of this study was to identify and quantify the misinformation present in online direct-to-consumer (DTC) advertising of SCT targeting patients with musculoskeletal disease in the U.S. It was hypothesized that DTC advertising of SCT contains substantial misinformation.

METHODS

A list of keywords was used to identify web sites of practices advertising SCT directly to patients with musculoskeletal disease. Web sites were evaluated to determine the specialties of providers offering SCT, types of SCT being advertised, and misinformation presented. Categories of misinformation included false general claims, inaccurate statements regarding mechanism of action, unfounded results, and scare tactics.

RESULTS

Of the 896 practice web sites included in the analysis, 95.9% contained at least 1 statement of misinformation, with a mean of 4.65 ± 3.66 statements of misinformation among the sites. Practices associated with an orthopaedic surgeon provided 22% fewer statements of misinformation than practices without an orthopaedic surgeon when we controlled for the effects of other specialties. Practices associated with a podiatrist also provided 22% fewer statements of misinformation.

CONCLUSIONS

Nearly all practices failed to accurately represent the clinical efficacy of SCT in DTC advertising. While practices associated with an orthopaedic surgeon were less likely to provide misinformation, the majority of all web sites contained some type of misinformation, ranging from errors in the basic science of stem cells to outright false and misleading claims of their clinical effectiveness.

Return to Sports After Surgical Treatment of Osteochondral Defects of the Talus: A Systematic Review of 2347 Cases

BACKGROUND

Osteochondral defects (OCDs) of the talus are found subsequent to ankle sprains and ankle fractures. With many surgical treatment strategies available, there is no clear evidence on return-to-sport (RTS) times and rates.

PURPOSE

To summarize RTS times and rates for talar OCDs treated by different surgical techniques.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The literature from January 1996 to November 2018 was screened, and identified studies were divided into 7 different surgical treatment groups. The RTS rate, with and without associated levels of activity, and the mean time to RTS were calculated per study. When methodologically possible, a simplified pooling method was used to combine studies within 1 treatment group. Study bias was assessed using the MINORS (Methodological Index for Non-Randomized Studies) scoring system.

RESULTS

A total of 61 studies including 2347 talar OCDs were included. The methodological quality of the studies was poor. There were 10 retrospective case series (RCSs) that investigated bone marrow stimulation in 339 patients, with a pooled mean rate of RTS at any level of 88% (95% CI, 84%-91%); 2 RCSs investigating internal fixation in 47 patients found a pooled RTS rate of 97% (95% CI, 85%-99%), 5 RCSs in which autograft transplantation was performed in 194 patients found a pooled RTS rate of 90% (95% CI, 86%-94%), and 3 prospective case series on autologous chondrocyte implantation in 39 patients found a pooled RTS rate of 87% (95% CI, 73%-94%). The rate of return to preinjury level of sports was 79% (95% CI, 70%-85%) for 120 patients after bone marrow stimulation, 72% (95% CI, 60%-83%) for 67 patients after autograft transplantation, and 69% (95% CI, 54%-81%) for 39 patients after autologous chondrocyte implantation. The mean time to RTS ranged from 13 to 26 weeks, although no pooling was possible for this outcome measure.

CONCLUSION

Different surgical treatment options for talar OCDs allow for adequate RTS times and rates. RTS rates decreased when considering patients' return to preinjury levels versus return at any level.

Stromal vascular fraction technologies and clinical applications

Introduction: The heterogeneous pool of cells found in the stromal vascular fraction of adipose tissue (SVF) and the purified mesenchymal stromal/stem cells (ASCs) isolated from this pool have increasingly been used as therapeutic tools in regenerative medicine.Areas covered: As SVF and ASCs are different, and should be used in different manners according to various clinical and biological indications, we reviewed the current literature, and focused on the clinical use of SVF to appraise the main medical fields for development. Both enzymatic digestion and mechanical disruption have been used to obtain SVF for non-homologous use. The safety and/or benefits of SVF have been examined in 71 clinical studies in various contexts, mainly musculoskeletal conditions, wound healing, urogenital, and cardiovascular and respiratory diseases. The use of SVF as a therapy remains experimental, with few clinical trials.Expert opinion: SVF provides a cellular and molecular microenvironment for regulation of ASC' activities under different clinical conditions. SVF may enhance angiogenesis and neovascularization in wound healing, urogenital and cardiovascular diseases. In joint conditions, therapeutic benefits may rely on paracrine immune-modulatory and anti-inflammatory mechanisms. Novel point of care methods are emerging to refine SVF in ways that meet the regulatory requirements for minimal manipulation.

High reported rate of return to play following bone marrow stimulation for osteochondral lesions of the talus

PURPOSE

The purpose of this study is to systematically review the literature and to evaluate the reported rehabilitation protocols, return to play guidelines and subsequent rates and timing of return to play following bone marrow stimulation (BMS) for osteochondral lesions of the talus (OLT).

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched according to the PRISMA guidelines in September 2017. The rate and timing of return to play was assessed. The rehabilitation protocols were recorded, including time to start range of motion, partial weight-bearing and complete weight-bearing.

RESULTS

Fifty-seven studies with 3072 ankles were included, with a mean age of 36.9 years (range 23-56.8 years), and a mean follow-up of 46.0 months (range 1.5-141 months). The mean rate of return to play was 86.8% (range 60-100%), and the mean time to return to play was 4.5 months (range 3.5-5.9 months). There was large variability in the reported rehabilitation protocols. Range of motion exercises were most often allowed to begin in the first week (46.2%), and second week postoperatively (23.1%). The most commonly reported time to start partial weight-bearing was the first week (38.8%), and the most frequently reported time of commencing full weight-bearing was 6 weeks (28.8%). Surgeons most often allowed return to play at 4 months (37.5%).

CONCLUSIONS

There is a high rate of return following BMS for OLT with 86.8% and the mean time to return to play was 4.5 months. There is also a significant deficiency in reported rehabilitation protocols, and poor quality reporting in return to play criteria. Early weightbearing and early postoperative range of motion exercises appear to be advantageous in accelerated return to sports.

LEVEL OF EVIDENCE

Level IV.

Reporting of Mesenchymal Stem Cell Preparation Protocols and Composition: A Systematic Review of the Clinical Orthopaedic Literature

BACKGROUND

Mesenchymal stem cells (MSCs) are increasingly being used in the treatment of a wide variety of sports-related conditions. Despite this enthusiasm, the biological properties of MSCs and their effects on musculoskeletal tissue healing remain poorly understood. MSC-based strategies encompass cell populations with heterogeneous phenotypes isolated from multiple tissues and using different methods. Therefore, comprehensive reporting of the source, preparation methods, and characteristics of MSC strategies is essential to enable interpretation of results.

PURPOSE

To perform a systematic review of levels of reporting of key variables in MSC preparation and composition for clinical studies evaluating MSC-based therapies in the treatment of musculoskeletal conditions.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of the clinical orthopaedic and sports medicine literature from 2002 to 2017 was performed. The following inclusion criteria were used: human clinical trials, published in the English language, involving the administration of MSC-based therapies for orthopaedic or sports medicine applications. In vitro or ex vivo studies, editorials, letters to the editor, and studies relating to cosmetic, neurological, or dental applications were excluded.

RESULTS

Of the 1259 studies identified on the initial search, 36 studies were found to satisfy the inclusion criteria for analysis on comprehensive review. Fifty-seven percent of studies evaluated bone marrow-derived MSCs, 41% evaluated adipose-derived MSCs, and 2% evaluated synovium-derived MSCs. Considerable deficiencies in the reporting of key variables, including the details of stem cell processing, culture conditions, and the characteristics of cell populations delivered, were noted. Overall, studies reported only 52% (range, 30%-80%) of variables that may critically influence outcome. No study provided adequate information relating to all of these variables.

CONCLUSION

All existing clinical studies evaluating MSCs for orthopaedic or sports medicine applications are limited by inadequate reporting of both preparation protocols and composition. Deficient reporting of the variables that may critically influence outcome precludes interpretation, prevents others from reproducing experimental conditions, and makes comparisons across studies difficult. We encourage the adoption of emerging minimum reporting standards for clinical studies evaluating the use of MSCs in orthopaedics.

Biologic Adjuvants for the Management of Osteochondral Lesions of the Talus

Surgical techniques for the management of recalcitrant osteochondral lesions of the talus have improved; however, the poor healing potential of cartilage may impede long-term outcomes. Repair (microfracture) or replacement (osteochondral transplants) is the standard of care. Reparative strategies lead to production of fibrocartilage, which, compared with the native type II articular cartilage, has decreased mechanical and wear properties. The success of osteochondral transplants may be hindered by poor integration between grafts and host that results in peripheral cell death and cyst formation. These challenges have led to the investigation of biologic adjuvants to augment treatment. In vitro and in vivo models have demonstrated promise for cartilage regeneration by decreasing inflammatory damage and increasing the amount of type II articular cartilage. Further research is needed to investigate optimal formulations and time points of administration. In addition, clinical trials are needed to investigate the long-term effects of augmentation.

Muscle stem cells: what's new in orthopedics?

Background and aim of the work: Adult stem cells were studied as a source of potentially useful development for tissue engineering and repair techniques. The aim of this review is to clarify the actual and possible uses of muscle stem cells in orthopedics. Methods: A selection of studies was made to obtain a homogeneous and up to date overview on the muscle stem cells applications. Results: In recent years muscle was studied as a good source of adult stem cells that can differentiate into different cell lineages. Muscle stem cells are a heterogeneous population of cells, which demonstrated in vitro a great potential for the regeneration and repair of muscle, bone and cartilage tissue. Among muscle stem cells, satellite stem cells are the most known progenitor cells: they can differentiate in osteoblasts, adipocytes, chondrocytes and myocytes. Conclusions: Although muscle stem cells are a promising field of research, more pre-clinical studies in animal models are still needed to determine the safety and efficiency of the transplant procedures in humans. (www.actabiomedica.it)

Intra-articular Mesenchymal Stem Cell Therapy for the Human Joint: A Systematic Review

BACKGROUND

Stem cell therapy is emerging as a potential treatment of osteoarthritis (OA) and chondral defects (CDs). However, there is a great deal of heterogeneity in the literature. The indications for stem cell use, the ideal tissue source, and the preferred outcome measures for stem cell-based treatments have yet to be determined.

PURPOSE

To provide clinicians with a comprehensive overview of the entire body of the current human literature investigating the safety and efficacy of intra-articular mesenchymal stem cell (MSC) therapy in all joints.

METHODS

To provide a comprehensive overview of the current literature, all clinical studies investigating the safety and efficacy of intra-articular MSC therapy were included. PubMed, MEDLINE, and Cochrane Library databases were searched for published human clinical trials involving the use of MSCs for the treatment of OA and CDs in all joints. A total of 3867 publications were screened.

RESULTS

Twenty-eight studies met the criteria to be included in this review. Fourteen studies treating osteoarthritis and 14 studies treating focal chondral defects were included. MSCs originating from bone marrow (13), adipose tissue (12), synovial tissue (2), or peripheral blood (2) were administered to 584 distinct individuals. MSCs were administered into the knee (523 knees), foot/ankle (61), and hip (5). The mean follow-up time was 24.4 months after MSC therapy. All studies reported improvement from baseline in at least 1 clinical outcome measure, and no study reported major adverse events attributable to MSC therapy.

DISCUSSION

The studies included in this review suggest that intra-articular MSC therapy is safe. While clinical and, in some cases, radiological improvements were reported for both OA and CD trials, the overall quality of the literature was poor, and heterogeneity and lack of reproducibility limit firm conclusions regarding the efficacy of these treatments.

CONCLUSION

This review provides strong evidence that autologous intra-articular MSC therapy is safe, with generally positive clinical outcomes.

Emerging Orthobiologic Techniques and the Future

The future of orthopedic surgery appears to be intimately associated with the development of orthobiologics to facilitate healing and the treatment of multiple disease processes. The orthopedic community should understand developmental processes to ensure that products are adequately studied and the effects are fully known before widespread implementation in the clinical setting. Technologies that embrace this paradigm will impact the field the most.

Injectable Systems for Intra-Articular Delivery of Mesenchymal Stromal Cells for Cartilage Treatment: A Systematic Review of Preclinical and Clinical Evidence

Stem cell-based therapy is a promising approach to treat cartilage lesions and clinical benefits have been reported in a number of studies. However, the efficacy of cell injection procedures may be impaired by cell manipulation and damage as well as by cell dissemination to non-target tissues. To overcome such issues, mesenchymal stromal cell (MSC) delivery may be performed using injectable vehicles as containment systems that further provide a favorable cell microenvironment. The aim of this systematic review was to analyze the preclinical and clinical literature on platelet-rich plasma (PRP), hyaluronic acid (HA), and hydrogels for the delivery of MSCs. The systematic literature search was performed using the PubMed and Web of science databases with the following string: "(stem cells injection) AND (platelet rich plasma OR PRP OR platelet concentrate OR biomaterials OR hyaluronic acid OR hydrogels)": 40 studies (19 preclinical and 21 clinical) met the inclusion criteria. This review revealed an increasing interest on the use of injectable agents for MSC delivery. However, while negligible adverse events and promising clinical outcomes were generally reported, the prevalence of low quality studies hinders the possibility to demonstrate the real benefits of using such injectable systems. Specific studies must be designed to clearly demonstrate the added benefits of these systems to deliver MSCs for the treatment of cartilage lesions and osteoarthritis.

Injectable Systems for Intra-Articular Delivery of Mesenchymal Stromal Cells for Cartilage Treatment: A Systematic Review of Preclinical and Clinical Evidence

Stem cell-based therapy is a promising approach to treat cartilage lesions and clinical benefits have been reported in a number of studies. However, the efficacy of cell injection procedures may be impaired by cell manipulation and damage as well as by cell dissemination to non-target tissues. To overcome such issues, mesenchymal stromal cell (MSC) delivery may be performed using injectable vehicles as containment systems that further provide a favorable cell microenvironment. The aim of this systematic review was to analyze the preclinical and clinical literature on platelet-rich plasma (PRP), hyaluronic acid (HA), and hydrogels for the delivery of MSCs. The systematic literature search was performed using the PubMed and Web of science databases with the following string: "(stem cells injection) AND (platelet rich plasma OR PRP OR platelet concentrate OR biomaterials OR hyaluronic acid OR hydrogels)": 40 studies (19 preclinical and 21 clinical) met the inclusion criteria. This review revealed an increasing interest on the use of injectable agents for MSC delivery. However, while negligible adverse events and promising clinical outcomes were generally reported, the prevalence of low quality studies hinders the possibility to demonstrate the real benefits of using such injectable systems. Specific studies must be designed to clearly demonstrate the added benefits of these systems to deliver MSCs for the treatment of cartilage lesions and osteoarthritis.

Stem Cell Therapy for Articular Cartilage Repair: Review of the Entity of Cell Populations Used and the Result of the Clinical Application of Each Entity

BACKGROUND

Following successful preclinical studies, stem cell therapy is emerging as a candidate for the treatment of articular cartilage lesions. Because stem cell therapy for cartilage repair in humans is at an early phase, confusion and errors are found in the literature regarding use of the term stem cell therapy in this field.

PURPOSE

To provide an overview of the outcomes of cartilage repair, elucidating the various cell populations used, and thus reduce confusion with regard to using the term stem cell therapy.

STUDY DESIGN

Systematic review.

METHODS

The authors systematically reviewed any studies on clinical application of mesenchymal stem cells (MSCs) in human subjects. A comprehensive search was performed in MEDLINE, EMBASE, the Cochrane Library, CINAHL, Web of Science, and Scopus for human studies that evaluated articular cartilage repair with cell populations containing MSCs. These studies were classified as using bone marrow-derived MSCs, adipose tissue-derived MSCs, peripheral blood-derived MSCs, synovium-derived MSCs, and umbilical cord blood-derived MSCs according to the entity of cell population used.

RESULTS

Forty-six clinical studies were identified to focus on cartilage repair with MSCs: 20 studies with bone marrow-derived MSCs, 21 studies with adipose tissue-derived MSCs, 3 studies with peripheral blood-derived MSCs, 1 study with synovium-derived MSCs, and 1 study with umbilical cord blood-derived MSCs. All clinical studies reported that cartilage treated with MSCs showed favorable clinical outcomes in terms of clinical scores or cartilage repair evaluated by MRI. However, most studies were limited to case reports and case series. Among these 46 clinical studies, 18 studies erroneously referred to adipose tissue-derived stromal vascular fractions as "adipose-derived MSCs," 2 studies referred to peripheral blood-derived progenitor cells as "peripheral blood-derived MSCs," and 1 study referred to bone marrow aspirate concentrate as "bone marrow-derived MSCs."

CONCLUSION

Limited evidence is available regarding clinical benefit of stem cell therapy for articular cartilage repair. Because the literature contains substantial errors in describing the therapeutic cells used, researchers need to be alert and observant of proper terms, especially regarding whether the cells used were stem cells or cell populations containing a small portion of stem cells, to prevent confusion in understanding the results of a given stem cell-based therapy.

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.

Debridement, Curettage, and Bone Marrow Stimulation: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle

BACKGROUND

The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on "Debridement, Curettage and Bone Marrow Stimulation" developed at the 2017 International Consensus Meeting on Cartilage Repair of the Ankle.

METHODS

Seventy-five international experts in cartilage repair of the ankle representing 25 countries and 1 territory were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 11 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed upon in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%.

RESULTS

A total of 14 statements on debridement, curettage, and bone marrow stimulation reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support, 12 reached strong consensus (greater than 75% agreement), and 1 achieved consensus. All statements reached at least 72% agreement.

CONCLUSIONS

This international consensus derived from leaders in the field will assist clinicians with debridement, curettage and bone marrow stimulation as a treatment strategy for osteochondral lesions of the talus.

Biological Therapies in Regenerative Sports Medicine

Regenerative medicine seeks to harness the potential of cell biology for tissue replacement therapies, which will restore lost tissue functionality. Controlling and enhancing tissue healing is not just a matter of cells, but also of molecules and mechanical forces. We first describe the main biological technologies to boost musculoskeletal healing, including bone marrow and subcutaneous fat-derived regenerative products, as well as platelet-rich plasma and conditioned media. We provide some information describing possible mechanisms of action. We performed a literature search up to January 2016 searching for clinical outcomes following the use of cell therapies for sports conditions, tendons, and joints. The safety and efficacy of cell therapies for tendon conditions was examined in nine studies involving undifferentiated and differentiated (skin fibroblasts, tenocytes) cells. A total of 54 studies investigated the effects of mesenchymal stem-cell (MSC) products for joint conditions including anterior cruciate ligament, meniscus, and chondral lesions as well as osteoarthritis. In 22 studies, cellular products were injected intra-articularly, whereas in 32 studies MSC products were implanted during surgical/arthroscopic procedures. The heterogeneity of clinical conditions, cellular products, and approaches for delivery/implantation make comparability difficult. MSC products appear safe in the short- and mid-term, but studies with a long follow-up are scarce. Although the current number of randomized clinical studies is low, stem-cell products may have therapeutic potential. However, these regenerative technologies still need to be optimized.

Primary Versus Secondary Osteochondral Autograft Transplantation for the Treatment of Large Osteochondral Lesions of the Talus

BACKGROUND

Recent studies have reported promising clinical results after osteochondral autograft transplantation (OAT) for the treatment of large osteochondral lesions of the talus (OLT). However, no study has yet compared clinical outcomes between primary and secondary OAT for large OLT.

PURPOSE

To compare clinical outcomes among patients with large OLT who receive primary OAT versus those who receive secondary OAT after failure of marrow stimulation and to identify factors associated with clinical failure.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

From 2005 to 2014, 46 patients with large OLT (≥150 mm²) underwent OAT: 18 underwent OAT as initial surgical management (primary OAT group), and 28 patients underwent secondary OAT after failure of previous arthroscopic marrow stimulation (secondary OAT group). In both groups, OAT procedures included arthroscopic inspection and debridement of concomitant soft tissue injuries. Clinical outcomes were assessed using pain visual analog scale (VAS), the Roles and Maudsley score, Foot and Ankle Outcome Scores (FAOS), and revisional surgery rates. Factors associated with clinical failures were evaluated using bivariate and logistic regression analyses. Survival outcomes were compared using Kaplan-Meier analysis.

RESULTS

Mean follow-up time was 6 years (range, 2-10.8 years). Mean lesion size was 194.9 mm² (range, 151.7-296.3 mm²). There were no significant differences between groups in patient demographics and preoperative findings. Postoperative pain VAS, Roles and Maudsley score, FAOS, and revisional surgery rates were not significantly different at last follow-up. Prior marrow stimulation was not significantly associated with clinical failure on bivariate analysis. Lesion size greater than 225 mm² on preoperative magnetic resonance imaging was significantly associated with clinical failure. Survival probabilities from Kaplan-Meier plots were not significantly different between the primary and secondary OAT groups ( P = .947).

CONCLUSION

Clinical outcomes of patients with large OLT treated with secondary OAT after failed marrow stimulation were found to be comparable with those who were treated with primary OAT. These results may be helpful to orthopaedic surgeons deciding appropriate surgical options for patients with large OLT.

Percutaneous Ultrasound-Guided Musculoskeletal Applications of Autologous Bone Marrow Aspirate Concentrate: Preliminary Experience From a Single Institution

Emerging musculoskeletal applications for local administration of autologous bone marrow aspirate concentrate (BMAC) include treatment of fractures, osteonecrosis, osteochondral injuries, osteoarthritis, ligament injury, tendon injury, and tendonopathies. Ultrasound-guided technique for various BMAC injection sites is detailed in this technical report and our preliminary clinical experience outlined.Five patients, 1 woman and 4 men, were treated with 6 peri/intratendinous (n = 4) or intraarticular (n = 2) BMAC injections between July 5, 2015 and December 31, 2016 for the clinical indications of common hamstrings origin tendinosis (n = 4), hip labral tear (n = 1), and osteochondral lesion of the talus (n = 1).All procedures were technically successful, with BMAC locally administered to the therapeutic target and no procedural complications observed. Clinical follow-up was available for 5 of 6 procedures. Four of 5 injections resulted in self-reported symptomatic improvement (clinical follow-up range, 2-12 months). One 72-year-old man with right common hamstrings origin tendinosis reported no improvement after BMAC injection.The technology is now available to support ultrasound-guided, autologous BMAC administration by the musculoskeletal interventionalist for common indications. Our initial clinical experience is consistent with early reports in the literature. This technique is well tolerated by symptomatic patients on an outpatient basis, and rates of self-reported symptomatic relief are high. Mechanism of action, long-term safety, and long-term clinical efficacy remain largely undefined.

Autologous Microfractured and Purified Adipose Tissue for Arthroscopic Management of Osteochondral Lesions of the Talus

In recent years, regenerative techniques have been increasingly studied and used to treat osteochondral lesions of the talus. In particular, several studies have focused their attention on mesenchymal stem cells derived from adipose tissue. Adipose-derived stem cells (ADSCs) exhibit morphological characteristics and properties similar to other mesenchymal cells, and are able to differentiate into several cellular lines. Moreover, these cells are also widely available in the subcutaneous tissue, representing 10 - 30% of the normal body weight, with a concentration of 5,000 cells per gram of tissue. In the presented technique, the first step involves harvesting ADSCs from the abdomen and a process of microfracture and purification; next, the surgical procedure is performed entirely arthroscopically, with less soft tissue dissection, better joint visualization, and a faster recovery compared with standard open procedures. Arthroscopy is characterized by a first phase in which the lesion is identified, isolated, and prepared with microperforations; the second step, performed dry, involves injection of adipose tissue at the level of the lesion. Between January 2016 and September 2016, four patients underwent arthroscopic treatment of osteochondral lesion of the talus with microfractured and purified adipose tissue. All patients reported clinical improvement six months after surgery with no reported complications. Functional scores at the latest follow-up are encouraging and confirm that the technique provides reliable pain relief and improvements in patients with osteochondral lesion of the talus.

Autophagy promotes MSC-mediated vascularization in cutaneous wound healing via regulation of VEGF secretion

Vascularization deficiency caused a lot of diseases, such as diabetes ulcer and myocardial infarction. Mesenchymal stem cells (MSCs), with the self-renewal and multipotent differentiation capacities, have been used for many diseases treatment through regulation microenvironment. Numerous studies reported that MSCs transplantation could largely improve cutaneous wound healing via paracrine secretion of growth factors. However, whether MSCs take part in the angiogenesis process directly remains elusive. Previous study proved that autophagy inhibited immunosuppressive function of MSCs and prevented the degradation of MSCs function in inflammatory and senescent microenvironment. Here, we proved that autophagy determines the therapeutic effect of MSCs in cutaneous wound healing through promoting endothelial cells angiogenesis and demonstrated that the paracrine of vascular endothelial growth factor (VEGF) in MSCs was required in wound site. We further revealed that autophagy enhanced the VEGF secretion from MSCs through ERK phosphorylation directly. Collectively, we put forward that autophagy mediated paracrine of VEGF plays a central role in MSCs cured cutaneous wound healing and may provide a new therapeutic method for angiogenesis-related diseases.

Mesenchymal Stem Cells: Potential Role in the Treatment of Osteochondral Lesions of the Ankle

Given articular cartilage has a limited repair potential, untreated osteochondral lesions of the ankle can lead to debilitating symptoms and joint deterioration necessitating joint replacement. While a wide range of reparative and restorative surgical techniques have been developed to treat osteochondral lesions of the ankle, there is no consensus in the literature regarding which is the ideal treatment. Tissue engineering strategies, encompassing stem cells, somatic cells, biomaterials, and stimulatory signals (biological and mechanical), have a potentially valuable role in the treatment of osteochondral lesions. Mesenchymal stem cells (MSCs) are an attractive resource for regenerative medicine approaches, given their ability to self-renew and differentiate into multiple stromal cell types, including chondrocytes. Although MSCs have demonstrated significant promise in in vitro and in vivo preclinical studies, their success in treating osteochondral lesions of the ankle is inconsistent, necessitating further clinical trials to validate their application. This review highlights the role of MSCs in cartilage regeneration and how the application of biomaterials and stimulatory signals can enhance chondrogenesis. The current treatments for osteochondral lesions of the ankle using regenerative medicine strategies are reviewed to provide a clinical context. The challenges for cartilage regeneration, along with potential solutions and safety concerns are also discussed.

Adipose-derived stem cells in orthopaedic pathologies

INTRODUCTION

To examine the current literature regarding the clinical application of adipose-derived stem cells (ADSCs) for the management of orthopaedic pathologies.

SOURCES OF DATA

MEDLINE,SCOPUS, CINAHL and EMBASE (1950 to April 14, 2017) were searched by two independent investigators for articles published in English. Reviews, meta-analyses, expert opinions, case reports, mini case series and editorials were excluded. Furthermore, we excluded animal studies, cadaveric studies and in vitro studies.

AREAS OF AGREEMENT

ADSCs seem to produce excellent clinical results. However, the length and modalities of follow-up in the different conditions are extremely variable. Nevertheless, it appears that the use of adipose-derived stem cells is associated with subjective and objective clinical improvements and minimal complication rates.

AREAS OF CONTROVERSY

None of the studies identified is a randomized double-blinded trial, and most of the selected studies present major limitations, and different methods, confounding the results of our review.

GROWING POINTS

It is necessary to conduct more and better studies to ascertain whether ADSCs really play a role in orthopaedic surgery with particular attention to ADSCs harvesting method, type of administration and the conditions treated.

AREAS TIMELY FOR DEVELOPING RESEARCH

The current literature regarding the use of ADSCs for orthopaedic pathologies is limited. At present, long-term safety is the biggest challenge of ADSCs based regenerative medicine.

LEVEL OF EVIDENCE

Level IV-Study of Level I, II, III, IV.

Advances and Prospects in Stem Cells for Cartilage Regeneration

The histological features of cartilage call attention to the fact that cartilage has a little capacity to repair itself owing to the lack of a blood supply, nerves, or lymphangion. Stem cells have emerged as a promising option in the field of cartilage tissue engineering and regenerative medicine and could lead to cartilage repair. Much research has examined cartilage regeneration utilizing stem cells. However, both the potential and the limitations of this procedure remain controversial. This review presents a summary of emerging trends with regard to using stem cells in cartilage tissue engineering and regenerative medicine. In particular, it focuses on the characterization of cartilage stem cells, the chondrogenic differentiation of stem cells, and the various strategies and approaches involving stem cells that have been used in cartilage repair and clinical studies. Based on the research into chondrocyte and stem cell technologies, this review discusses the damage and repair of cartilage and the clinical application of stem cells, with a view to increasing our systematic understanding of the application of stem cells in cartilage regeneration; additionally, several advanced strategies for cartilage repair are discussed.

Evaluation and Management of Osteochondral Lesions of the Talus

Osteochondral lesions of the talus are common injuries that affect a wide variety of active patients. The majority of these lesions are associated with ankle sprains and fractures though several nontraumatic etiologies have also been recognized. Patients normally present with a history of prior ankle injury and/or instability. In addition to standard ankle radiographs, magnetic resonance imaging and computed tomography are used to characterize the extent of the lesion and involvement of the subchondral bone. Symptomatic nondisplaced lesions can often be treated conservatively within the pediatric population though this treatment is less successful in adults. Bone marrow stimulation techniques such as microfracture have yielded favorable results for the treatment of small (<15 mm) lesions. Osteochondral autograft can be harvested most commonly from the ipsilateral knee and carries the benefit of repairing defects with native hyaline cartilage. Osteochondral allograft transplant is reserved for large cystic lesions that lack subchondral bone integrity. Cell-based repair techniques such as autologous chondrocyte implantation and matrix-associated chondrocyte implantation have been increasingly used in an attempt to repair the lesion with hyaline cartilage though these techniques require adequate subchondral bone. Biological agents such as platelet-rich plasma and bone marrow aspirate have been more recently studied as an adjunct to operative treatment but their use remains theoretical. The present article reviews the current concepts in the evaluation and management of osteochondral lesions of the talus, with a focus on the available surgical treatment options.

Cartilage repair in the degenerative ageing knee

Background and purpose - Cartilage damage can develop due to trauma, resulting in focal chondral or osteochondral defects, or as more diffuse loss of cartilage in a generalized organ disease such as osteoarthritis. A loss of cartilage function and quality is also seen with increasing age. There is a spectrum of diseases ranging from focal cartilage defects with healthy surrounding cartilage to focal lesions in degenerative cartilage, to multiple and diffuse lesions in osteoarthritic cartilage. At the recent Aarhus Regenerative Orthopaedics Symposium (AROS) 2015, regenerative challenges in an ageing population were discussed by clinicians and basic scientists. A group of clinicians was given the task of discussing the role of tissue engineering in the treatment of degenerative cartilage lesions in ageing patients. We present the outcomes of our discussions on current treatment options for such lesions, with particular emphasis on different biological repair techniques and their supporting level of evidence. Results and interpretation - Based on the studies on treatment of degenerative lesions and early OA, there is low-level evidence to suggest that cartilage repair is a possible treatment for such lesions, but there are conflicting results regarding the effect of advanced age on the outcome. We concluded that further improvements are needed for direct repair of focal, purely traumatic defects before we can routinely use such repair techniques for the more challenging degenerative lesions. Furthermore, we need to identify trigger mechanisms that start generalized loss of cartilage matrix, and induce subchondral bone changes and concomitant synovial pathology, to maximize our treatment methods for biological repair in degenerative ageing joints.

Mesenchymal stem cell subpopulations: phenotype, property and therapeutic potential

Mesenchymal stem cells (MSC) are capable of differentiating into cells of multiple cell lineages and have potent paracrine effects. Due to their easy preparation and low immunogenicity, MSC have emerged as an extremely promising therapeutic agent in regenerative medicine for diverse diseases. However, MSC are heterogeneous with respect to phenotype and function in current isolation and cultivation regimes, which often lead to incomparable experimental results. In addition, there may be specific stem cell subpopulations with definite differentiation capacity toward certain lineages in addition to stem cells with multi-differentiation potential. Recent studies have identified several subsets of MSC which exhibit distinct features and biological activities, and enhanced therapeutic potentials for certain diseases. In this review, we give an overview of these subsets for their phenotypic, biological and functional properties.

Diagnosis and treatment of osteochondral lesions of the ankle: current concepts

We conducted a wide-ranging review of the literature regarding osteochondral lesions of the ankle, with the aim of presenting the current concepts, treatment options, trends and future perspectives relating to this topic.

Mesenchymal stromal cells for cartilage repair in osteoarthritis

Treatment for articular cartilage damage is quite challenging as it shows limited repair and regeneration following injury. Non-operative and classical surgical techniques are inefficient in restoring normal anatomy and function of cartilage in osteoarthritis (OA). Thus, investigating new and effective strategies for OA are necessary to establish feasible therapeutic solutions. The emergence of the new discipline of regenerative medicine, having cell-based therapy as its primary focus, may enable us to achieve repair and restore the damaged articular cartilage. This review describes progress and development of employing mesenchymal stromal cell (MSC)-based therapy as a promising alternative for OA treatment. The objective of this review is to first, discuss how in vitro MSC chondrogenic differentiation mimics in vivo embryonic cartilage development, secondly, to describe various chondrogenic differentiation strategies followed by pre-clinical and clinical studies demonstrating their feasibility and efficacy. However, several challenges need to be tackled before this research can be translated to the clinics. In particular, better understanding of the post-transplanted cell behaviour and learning to enhance their potency in the disease microenvironment is essential. Final objective is to underscore the importance of isolation, storage, cell shipment, route of administration, optimum dosage and control batch to batch variations to realise the full potential of MSCs in OA clinical trials.