Subchondral stem cell therapy versus contralateral total knee arthroplasty for osteoarthritis following secondary osteonecrosis of the knee

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.

The reimbursement system can influence the treatment choice and favor joint replacement versus other less invasive solutions in patients affected by osteoarthritis

PURPOSE

The aim of this study was to assess how physicians perceive the role of the reimbursement system and its potential influence in affecting their treatment choice in the management of patients affected by osteoarthritis (OA).

METHODS

A survey was administered to 283 members of SIAGASCOT (Italian Society of Arthroscopy, Knee, Upper Limb, Sport, Cartilage and Orthopaedic Technologies), a National scientific orthopaedic society. The survey presented multiple choice questions on the access allowed by the current Diagnosis-Related Groups (DRG) system to all necessary options to treat patients affected by OA and on the influence toward prosthetic solutions versus other less invasive options.

RESULTS

Almost 70% of the participants consider that the current DRG system does not allow access to all necessary options to best treat patients affected by OA. More than half of the participants thought that the current DRG system favors the choice of prosthetic solutions (55%) and that it can contribute to the increase in prosthetic implantation at the expense of less invasive solutions (54%). The sub-analyses based on different age groups, professional roles, and places of work allowed to evaluate the response in each specific category, confirming the findings for all investigated aspects.

CONCLUSIONS

This survey documented that the majority of physicians consider that the reimbursement system can influence the treatment choice when managing OA patients. The current DRG system was perceived as unbalanced in favor of the choice of the prosthetic solution, which could contribute to the increase in prosthetic implantation at the expense of other less invasive options for OA management.

Total Knee Arthroplasty (TKA): When Do the Risks of TKA Overcome the Benefits? Double Risk of Failure in Patients up to 65 Years Old

OBJECTIVE

The aim of this study was to document the survival rate in the middle-aged patient group up to 65 years old and to compare it with other age groups of patients undergoing total knee arthroplasty (TKA) for knee osteoarthritis (OA).

DESIGN

The Register of Orthopaedic Prosthetic Implants (RIPO) regional registry was used to analyze the results of patients <80 years old affected by primary OA and treated with TKA from 2000 to 2019. The database was investigated according to the age group: younger than 50 years, 50-65 years, or 66-79 years, with the aim to estimate revision surgeries and implant survivorship.

RESULTS

A total of 45,488 TKAs for primary OA were included in the analysis (M: 11,388; F: 27,846). The percentage of patients <65 years old increased from 13.5% to 24.8% between 2000 and 2019 (P < 0.0001). The survival analysis showed an overall influence of age on the implant revision rate (P < 0.0001), with an estimated survival rate of 78.7%, 89.4%, and 94.8% at 15 years in the 3 groups, respectively. Compared with the older-aged group, the relative risk of failure was 3.1 (95% confidence interval [CI] = 2.2-4.3; P < 0.001) higher in patients <50 years old and 1.8 (95% CI = 1.6-2.0; P < 0.001) higher in patients 50-65 years old.

CONCLUSIONS

TKA use in the middle-aged patient population up to 65 years old increased significantly over time. These patients present a double risk of failure with respect to older patients. This is particularly important considering the increasing life expectancy and the emergence of new joint preserving strategies, which could postpone the need for TKA to an older age.

Core Decompression Combined with Intraosseous Autologous Conditioned Plasma Injections Decreases Pain and Improves Function in Patients with Symptomatic Knee Bone Marrow Lesions

The purpose of this prospective case series was to determine the effectiveness of using a combination of the core decompression and injection of autologous conditioned plasma (ACP) for the treatment of symptomatic knee bone marrow lesions (BML), as well as to report on the preliminary clinical results based on magnetic resonance imaging (MRI) and patient-reported outcomes (PROMs). Patients with OA-related BML who failed to improve on conservative treatment for three months underwent an identical procedure consisting of arthroscopy, core decompression, and the intraosseous injection of ACP and were followed up for 12 months. A statistically significant reduction in pain and an improvement in function, as measured by the Numeric Pain Rating Scale (NPRS) and Knee Injury and Osteoarthritis Outcome Score (KOOS), was observed at one-week follow-up (8.3 ± 0.8 to 1.5 ± 1.0; p ≤ 0.001 and 33.4 ± 10.6 to 53.9 ± 13.6; p ≤ 0.001 respectively). After six weeks, weight-bearing was allowed, but the trend did not change-the NPRS continued to be low (average 1.4 on 12-month follow-up) and the total KOOS increased 44.6 points from the baseline (average 78.0 on 12-month follow-up). The Whole-Organ Magnetic Resonance Imaging Score improved from 66.1 ± 19.4 prior to surgery to 58.0 ± 15.9 (p < 0.001) after 3 months. In our study, there was no control group, randomisation was not performed, and the sample size was relatively small. A combination of core decompression and the intraosseous injection of ACP into the affected subchondral area proved to be a safe and effective procedure that provides rapid pain relief and a significant increase in joint function up to one year postoperatively.

AAOS Technology Overview Summary: Concentrated Bone Marrow Aspirate for Knee Osteoarthritis

The Concentrated Bone Marrow Aspirate (CBMA) for Knee Osteoarthritis Technology Overview is based on a systematic review of current scientific and clinical research. Through analysis of the current best evidence, this technology overview seeks to evaluate the efficacy of CBMA for patients with knee osteoarthritis. The systematic literature review resulted in 12 articles: three high-quality, four moderate-quality, and five low-quality. The findings of these studies were summarized to present findings on CBMA versus placebo and CBMA versus other treatment modalities. In addition, the work group highlighted areas for needed additional research when evidence proved lacking on the topic and carefully noted the potential harms associated with an intervention, required resource utilization, acceptability, and feasibility.

Carboplasty, a Simple Tibial Marrow Technique for Knee Osteoarthritis: A Placebo-Controlled Randomized Trial

Background

Carboplasty is a new minimally invasive technique for knee osteoarthritis (OA) that consists of injecting tibial marrow aspirate into the bone-cartilage interface as well as intra-articularly.

Purpose

To compare the clinical and imaging outcomes, as well as the safety, of carboplasty for symptomatic knee OA in a placebo-controlled trial.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

The authors conducted a randomized controlled trial to compare carboplasty with placebo for the treatment of symptomatic knee OA. Patients who had failed medical treatment and had bone edema on magnetic resonance imaging (MRI) were randomized in a 1:1 ratio to carboplasty or placebo. The primary outcome of the study was the Numeric Pain Rating Scale (NPRS) for the knee at 1 year (scores range from 0 to 10, with a higher score indicating worse pain). Secondary outcomes were the Knee injury and Osteoarthritis Outcome Score (KOOS), treatment responder rate (based on achieving the minimal clinically important difference of the NPRS), MRI bone edema reduction, and treatment safety.

Results

In total, 50 patients (25 carboplasty vs 25 placebo) were enrolled and followed up with for an average of 18 months (range, 14-24 months). The average NPRS at baseline decreased from 7.1 ± 0.9 to 2.9 ± 2.1 (P < .001) at 1 year in the carboplasty group and from 7.7 ± 0.9 to 4.9 ± 2.2 (P < .001) in the placebo group. On average, patients after carboplasty improved 60% from their initial NPRS, and patients after placebo improved 37% (P = .003). Patients had a statistically significantly greater improvement from baseline in all KOOS subscales in the carboplasty group compared with the placebo group (P < .001). The responder rates were 96% for carboplasty and 76% for placebo (P = .098). Bone edema was reduced in 72% of patients in the carboplasty group and 44% of patients in the placebo group (P = .045). Neither group had adverse events related to treatment.

Conclusion

Carboplasty resulted in greater pain reduction, a significantly greater improvement in all KOOS subscales, and a similar safety profile compared with placebo in patients with symptomatic knee OA and bone edema.

Registration

ISRCTN69838191 (ISRCT Registry).

Intra-osseous infiltration of adipose mesenchymal stromal cells and plasma rich in growth factors to treat acute full depth cartilage defects in a rabbit model: Serum osteoarthritis biomarkers and macroscopical assessment

Introduction

Intra-articular infiltration of plasma rich in growth factors (PRGF) and adipose mesenchymal stromal cells (AMSCs) are known to inhibit osteoarthritis progression. However, in severely affected patients, the treatment cannot reach the deeper layers of the articular cartilage; thus, its potential is limited. To overcome this limitation, intra-osseous infiltrations have been suggested. The purpose of this study is to assess the impact of intra-osseous infiltration therapies on serum biomarkers of osteoarthritis and to assess cartilage regeneration macroscopically.

Materials and methods

A total of 80 rabbits were divided into four groups based on the intra-osseous treatment administered on the day of surgery: control, PRGF, AMSCs and a combination of PRGF + AMSCs. In addition, all groups received a single intra-articular administration of PRGF on the same day. Serum biomarker levels were measured before infiltration and 28-, 56-, and 84-days post infiltration, and macroscopical assessment was conducted at 56- and 84-days follow-up post infiltration.

Results

In the PRGF + AMSCs group, significantly lower concentrations of hyaluronic acid and type II collagen cleavage neoepitope were recorded at all time points during the study, followed by PRGF, AMSCs and control groups. Regarding macroscopical assessment, lower scores were obtained in PRGF + AMSCs group at all study times.

Discussion

The results suggest that the combination of intra-articular PRGF with intra-osseous PRGF or AMSCs achieves better results in rabbits with acute chondral defects and that intra-osseous infiltration is a safe procedure.

Engineering exosomes for bone defect repair

Currently, bone defect repair is still an intractable clinical problem. Numerous treatments have been performed, but their clinical results are unsatisfactory. As a key element of cell-free therapy, exosome is becoming a promising tool of bone regeneration in recent decades, because of its promoting osteogenesis and osteogenic differentiation function in vivo and in vitro. However, low yield, weak activity, inefficient targeting ability, and unpredictable side effects of natural exosomes have limited the clinical application. To overcome the weakness, various approaches have been applied to produce engineering exosomes by regulating their production and function at present. In this review, we will focus on the engineering exosomes for bone defect repair. By summarizing the exosomal cargos affecting osteogenesis, the strategies of engineering exosomes and properties of exosome-integrated biomaterials, this work will provide novel insights into exploring advanced engineering exosome-based cell-free therapy for bone defect repair.

Combined subchondral and intra-articular injections of bone marrow aspirate concentrate provide stable results up to 24 months

PURPOSE

The aim of this study was to evaluate the clinical and imaging findings up to 24 months of follow-up in patients treated with combined subchondral and intra-articular bone marrow aspirate concentrate (BMAC) injections for the treatment of knee osteoarthritis (OA).

METHODS

Thirty consecutive patients (19 males, 11 females) aged between 40 and 75 years (mean age 56.4 ± 8.1 years) with unilateral symptomatic knee OA (Kellgren-Lawrence 2-3) were included in the study. Patients were treated with combined intra-articular and subchondral bone BMAC injections (total 9 ml) under fluoroscopic control. IKDC subjective score, VAS for pain, KOOS, and EQ-VAS were prospectively evaluated up to 24 months. Radiographs were performed at baseline and at 24 months after the procedure. MRI was evaluated with the WORMS score at baseline, 6-12 months, and 24 months of follow-up. The statistical analysis was performed using SPSS v.19.0 and for all tests p < 0.05 was considered significant.

RESULTS

No major complications and a 13% failure rate were reported. The IKDC subjective score remained stable from 62.6 ± 19.4 at 12 months to 63.4 ± 17.1 at 24 months (both p < 0.0005 compared to baseline, 40.5 ± 12.5). Similar improvements were reported for all KOOS subscales, while EQ-VAS did not report any significant improvement. VAS pain worsened from 3.0 ± 1.9 at 12 months to 4.4 ± 1.8 at the final follow-up (p = 0.0001), although remaining lower compared to the baseline value of 6.3 ± 1.8 (p = 0.002). The radiographic evaluation did not reveal signs of improvement or deterioration of the OA grade. The MRI findings showed a worsening in marginal osteophytes and synovitis, but a significant reduction of bone marrow edema at 24 months (p < 0.0005).

CONCLUSION

Combined intra-articular and subchondral BMAC injections provided clinical and imaging benefits up to 24 months for the treatment of symptomatic knee OA, with durable clinical results, a low failure rate, and a significant reduction of bone marrow edema.

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

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

•

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

•

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

•

MSCs used as subchondral injection or surgical augmentation in osteochondral defects

•

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

•

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

The Effectiveness and Safety of Mesenchymal Stem Cells in the Treatment of Osteoarthritis: A Systematic Review and Meta-analysis of 28 Randomized Controlled Trials

Objective

To evaluate the effectiveness and safety of mesenchymal stem cells (MSCs) in the treatment of osteoarthritis (OA).

Methods

Chinese databases (such as CNKI and SinoMed) and English databases (such as PubMed and Embase) were searched to collect randomized controlled trials (RCTs) of MSCs in the treatment of OA. The retrieval time is from inception to October 10, 2021. The literature was strictly selected according to the inclusion and exclusion criteria, data was extracted, and the quality was evaluated. RevMan 5.3 software was used for meta-analysis. STATA was used to evaluate publication bias. The registration number of this systematic review and meta-analysis is CRD42021277145.

Results

A total of 28 RCTs involving 1494 participants were included. The primary outcomes showed that MSCs may reduce WOMAC pain and VAS at the 3rd-month follow-up [WOMAC pain: -3.81 (-6.95, -0.68), P = 0.02. VAS: -1.11 (-1.53, -0.68), P < 0.00001], and the effect lasts for at least 12 months [WOMAC pain: -4.29 (-7.12, -1.47), P = 0.003. VAS: -1.77 (-2.43, -1.12), P < 0.00001]. MSCs may also reduce WOMAC stiffness and physical function at the 6th-month follow-up [WOMAC stiffness: -1.12 (-2.09, -0.14), P = 0.03. WOMAC physical function: -4.40 (-6.84, -1.96), P = 0.0004], and the effect lasts for at least 12 months [WOMAC stiffness: -0.99 (-1.95, -0.03), P = 0.04. WOMAC physical function: -3.26 (-5.91, -0.61), P = 0.02]. The improvement of WOMAC pain, VAS, WOMAC stiffness, and WOMAC physical function may be clinically significant. Meanwhile, after the MSC injection, Lequesne had been reduced compared with the control group [-4.49 (-8.21, -0.77), P = 0.002]. For adverse events, there is no significant difference in the safety of MSC injection and the control group [1.20 (0.97, 1.48), P = 0.09]. The quality of WOMAC physical function and adverse events were moderate.

Conclusion

Based on current evidence, MSCs may be a safety therapy that have a good curative effect in the treatment of OA, the onset time is no later than 3 months, and the time to maintain the curative effect is no less than 12 months. However, these results should be generalized with caution due to the generally low quality of evidence and RCTs.

BMSC exosome-enriched acellular fish scale scaffolds promote bone regeneration

Tissue engineering scaffolds are essential for repairing bone defects. The use of biomimetic scaffolds for bone tissue engineering has been investigated for decades. To date, the trend in this area has been moved toward the construction of biomimetic acellular scaffolds with effective modification to enhance the osteogenic differentiation efficiency of bone marrow mesenchymal stem cells (BMSCs). The exosomes derived from BMSCs have been shown as a potential therapeutic tool for repairing bone defects. In this study, we demonstrated the pro-osteogenic effects of exosomes derived form osteogenic differentiated BMSCs (OBMSC) and presented a novel exosmes-functionalized decellularized fish scale (DE-FS) scaffold for promoting bone regeneration in vivo. The DE-FS scaffolds were obtained through decellularization and decalcification processes, which exhibited high biocompatibility and low immunological rejection. The intrinsic anisotropic structures of DE-FS could enhance the adhesion and proliferation ability of BMSCs in vitro. In addition, we demonstrated that the porous structure of DE-FS endowed them with the capacity to load and release exosomes to BMSCs, resulting in the enhanced osteogenic differentiation of BMSCs. Concerning these pro-osteogenic effects, it was further proved that OBMSC exosome-modified DE-FS scaffolds could effectively promote bone regeneration in the mouse calvarial defect models. In conclusion, our work provided a new insight to design exosome-riched biomimetic scaffolds for bone tissue engineering and clinical applications.

Prospective double-blind randomised controlled trial protocol comparing bone marrow aspirate concentrate intra-articular injection combined with subchondral injection versus intra-articular injection alone for the treatment of symptomatic knee osteoarthritis

INTRODUCTION

Subchondral and intra-articular injections of bone marrow aspirate concentrate (BMAC) showed promising results for knee osteoarthritis (OA) patients. To date, there is no evidence to demonstrate whether the combination of these treatments provides higher benefits than the intra-articular injection alone.

METHODS AND ANALYSIS

Eighty-six patients with symptomatic knee OA (aged between 40 and 70 years) are randomised to BMAC intra-articular injection combined with subchondral BMAC injection or BMAC intra-articular injection alone in a ratio of 1:1. The primary outcome is the total Western Ontario and McMaster Universities Osteoarthritis Index, the secondary outcomes are the International Knee Documentation Committee Subjective and Objective Knee Evaluation Form, the Tegner activity scale, the EuroQol-Visual Analogue Scale, and the health questionnaire European Quality of Life Five Dimension score. Additional CT and MRI evaluations are performed at the baseline assessment and at the final 12-month follow-up. The hypothesis is that the combined injections provide higher knee pain and function improvement compared with BMAC intra-articular injection alone. The primary analysis follows an intention to treat principle.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Emilia Wide Area Ethical Committee of the Emilia-Romagna Region (CE-AVEC), Bologna, Italy. Written informed consent is obtained from all the participants. Findings of this study will be disseminated through peer-reviewed publications and conference presentations.

PROTOCOL VERSION

Version 1 (14 May 2018).

TRIAL REGISTRATION NUMBER

NCT03876795.

Subchondral versus intra-articular orthobiologic injections for the treatment of knee osteoarthritis: a review

Recent perspectives suggest that osteoarthritis (OA) is a disease involving not only the articular cartilage but also the osteochondral unit, including the synovium, supportive cartilage and subchondral bone. Current conservative treatments for OA are symptomatic and do not prevent progression or reverse the disease process. Compelling data show that intra-articular orthobiologic injections, such as platelet-rich plasma and mesenchymal stromal cells, are effective in providing relief of OA symptoms. However, recent data suggest that injections of orthobiologics into the subchondral bone may be superior to intra-articular injections for the management of OA. This review highlights the rationale and current evidence for intra-articular and subchondral bone injections of orthobiologics for the treatment of OA.

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

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

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.

Knee Intraosseous Injections: A Systematic Review of Clinical Evidence of Different Treatment Alternatives

OBJECTIVE

To systematically review the available clinical evidence regarding the safety and efficacy of knee intraosseous injections for the treatment of bone marrow lesions in patients affected by knee osteoarthritis.

DESIGN

A literature search was carried out on PubMed, Embase, and Google Scholar databases in January 2020. The following inclusion criteria were adopted: (1) studies of any level of evidence, dealing with subchondral injection of bone substitute materials and/or biologic agents; (2) studies with minimum 5 patients treated; and (3) studies with at least 6 months' follow-up evaluation. All relevant data concerning clinical outcomes, adverse events, and rate of conversion to arthroplasty were extracted.

RESULTS

A total of 12 studies were identified: 7 dealt with calcium phosphate administration, 3 with platelet-rich plasma, and 2 with bone marrow concentrate injection. Only 2 studies were randomized controlled trials, whereas 6 studies were prospective and the remaining 4 were retrospective. Studies included a total of 459 patients treated with intraosseous injections. Overall, only a few patients experienced adverse events and clinical improvement was documented in the majority of trial. The lack of any comparative evaluation versus subchondral drilling alone is the main limitation of the available evidence.

CONCLUSIONS

Knee intraosseous injections are a minimally invasive and safe procedure to address subchondral bone damage in osteoarthritic patients. They are able to provide beneficial effects at short-term evaluation. More high-quality evidence is needed to confirm their potential and to identify the best product to adopt in clinical practice.

Subchondral and intra-articular injections of bone marrow concentrate are a safe and effective treatment for knee osteoarthritis: a prospective, multi-center pilot study

PURPOSE

Subchondral bone is becoming a treatment target for knee OA patients, with promising early findings on the use of bone marrow aspirate concentrate (BMAC). The aim of this prospective, multi-centric pilot study was to evaluate safety as well as clinical and MRI outcomes of a combined approach of intra-articular and subchondral BMAC injections.

METHODS

Thirty patients (19 men, 11 women, 56.4 ± 8.1 years) with symptomatic knee OA were treated with a combination of an intra-articular and two subchondral BMAC injections (femoral condyle and tibial plateau). Patients were evaluated at baseline and at 1-3-6-12 months of follow-up with the IKDC subjective, VAS, KOOS, and EQ-VAS scores. The MRI evaluation was performed with the WORMS score.

RESULTS

No major complications were reported and only two patients were considered treatment failures, requiring a new injective or surgical treatment. The IKDC subjective score improved significantly from 40.5 ± 12.5 to 59.9 ± 16.1 at 3 months, 59.1 ± 12.2 at 6 months, and 62.6 ± 19.4 at 12 months (p < 0.0005). A similar improvement was reported for VAS pain and all KOOS subscales at all follow-ups, while EQ-VAS did not show any significant improvement. The MRI analysis showed a significant bone marrow edema reduction (p = 0.003), while the remaining WORMS parameters did not show any significant changes.

CONCLUSION

The pilot evaluation of this combined BMAC injective treatment showed safety and positive outcome up to 12 months of follow-up in patients with symptomatic knee OA associated with subchondral bone alterations. These findings suggest that targeting both subchondral bone and joint environment can provide promising results, and that BMAC can be a valid option for this combined approach to treat knee OA.

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

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

Mechanobiology-based physical therapy and rehabilitation after orthobiologic interventions: a narrative review

PURPOSE

This review aims to summarize the evidence for the role of mechanotherapies and rehabilitation in supporting the synergy between regeneration and repair after an orthobiologic intervention.

METHODS

A selective literature search was performed using Web of Science, OVID, and PubMed to review research articles that discuss the effects of combining mechanotherapy with various forms of regenerative medicine.

RESULTS

Various mechanotherapies can encourage the healing process for patients at different stages. Taping, bracing, cold water immersion, and extracorporeal shockwave therapy can be used throughout the duration of acute inflammatory response. The regulation of angiogenesis can be sustained with blood flow restriction and resistance training, whereas heat therapy and tissue loading during exercise are recommended in the remodeling phase.

CONCLUSION

Combining mechanotherapy with various forms of regenerative medicine has shown promise for improving treatment outcomes. However, further studies that reveal a greater volume of evidence are needed to support clinical decisions.

Acetabular Bone Marrow Aspiration During Total Hip Arthroplasty

Biologically augmented surgical treatments of orthopaedic conditions are increasingly popular. Bone marrow aspirate concentrate is a key orthobiologic tissue source, and the field is moving from the standard iliac crest marrow aspiration toward local aspirations of marrow depots that are accessible during the standard-of-care procedures in an attempt to reduce morbidity, surgery time, and cost. Here, we present the aspiration of the standard iliac marrow depot, but through a novel acetabular approach during total hip arthroplasty. This procedure markedly simplifies biologic augmentation with bone marrow aspirate concentrate in this large patient cohort.

Atraumatic Medullary Osteonecrosis of the Tibia and Femur Treated With Intraosseous Orthobiologics

Osteonecrosis (ON) is a painful condition involving bony cell death with resultant architectural collapse. This report discusses the case of a 50-year-old Caucasian female who presented to an outpatient musculoskeletal clinic with severe chronic left knee pain. She had a history of ulcerative colitis and resultant chronic corticosteroid exposure with subsequent development of knee ON. She was treated with an intraosseous autologous bone marrow concentrate (BMC), demineralized bone matrix (DBM), and platelet-rich plasma (PRP) injection. At 11 months post-injection, she demonstrated a significant improvement in pain scores, mobility, activity, and decreased narcotic use. Intraosseous orthobiologic injection for the treatment of knee ON is a promising procedure with a reasonable safety profile that warrants further study as an alternative to surgical intervention.

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.

Advantages and challenges of stem cell therapy for osteoarthritis (Review)

Osteoarthritis (OA) is a degenerative disorder of the cartilage and is one of the leading causes of disability, particularly amongst the elderly, wherein patients with advanced-stage OA experience chronic pain and functional impairment of the limbs, thus resulting in a significantly reduced quality of life. The currently available treatments primarily revolve around symptom management, and is thus palliative rather than curative. The aim of the present review is to briefly discuss the limitations of some of the currently available treatments for patients with OA, and highlight the value of the potential use of stem cells in cellular therapy, which is widely regarded as the breakthrough that can address the present unmet medical needs for treatment of degenerative diseases, such as OA. The advantages of stem cell therapy, particularly mesenchymal stem cells, and the challenges involved are also discussed in this review.

Role of Scaffolds, Subchondral, Intra-Articular Injections of Fresh Autologous Bone Marrow Concentrate Regenerative Cells in Treating Human Knee Cartilage Lesions: Different Approaches and Different Results

The value of bone marrow aspirate concentrates for treatment of human knee cartilage lesions is unclear. Most of the studies were performed with intra-articular injections. However, subchondral bone plays an important role in the progression of osteoarthritis. We investigated by a literature review whether joint, subchondral bone, or/and scaffolds implantation of fresh autologous bone marrow aspirate concentrated (BMAC) containing mesenchymal stem cells (MSCs) would improve osteoarthritis (OA). There is in vivo evidence that suggests that all these different approaches (intra-articular injections, subchondral implantation, scaffolds loaded with BMAC) can improve the patient. This review analyzes the evidence for each different approach to treat OA. We found that the use of intra-articular injections resulted in a significant relief of pain symptoms in the short term and was maintained in 12 months. However, the clinical trials indicate that the application of autologous bone marrow concentrates in combination with scaffolds or in injection in the subchondral bone was superior to intra-articular injection for long-term results. The tendency of MSCs to differentiate into fibrocartilage affecting the outcome was a common issue faced by all the studies when biopsies were performed, except for scaffolds implantation in which some hyaline cartilage was found. The review suggests also that both implantation of subchondral BMAC and scaffolds loaded with BMAC could reduce the need for further surgery.

Outcomes of Cemented Total Knee Arthroplasty for Secondary Osteonecrosis of the Knee

BACKGROUND

Secondary osteonecrosis of the knee (SOK) generally occurs in relatively young patients; at advanced stages of SOK, the only viable surgical option is total knee arthroplasty (TKA). We conducted a retrospective study to investigate implant survivorship, clinical and radiographic outcomes, and complications of contemporary cemented bicompartmental TKA with/without patellar resurfacing for SOK.

METHODS

Thirty-eight cemented TKAs in 27 patients with atraumatic SOK, mean age 43 years (17 to 65), were retrospectively reviewed. Seventy-four percent had a history of corticosteroid use, and 18% had a history of alcohol abuse. Patellar osteonecrosis was coincidentally found in six knees (16%), and all were asymptomatic without joint collapse. The mean followup was 7 years (2 to 12). Knee Society Score (KSS) and radiographic outcomes were evaluated at 6 weeks, 1 year, then every 2 to 3 years.

RESULTS

Ninety-two percent had implant survivorship free from revision with significant improvement in KSS. Causes of revision included aseptic tibial loosening (one), deep infection (one), and instability with patellofemoral issues (one). Four of six cases also with patellar osteonecrosis received resurfacing, including one with periprosthetic patellar fracture after minor trauma, with satisfactory clinical results after conservative treatment. None of the unrevised knees had progressive radiolucent lines or evidence of loosening. An unresurfaced patella, use of a stem extension or a varus-valgus constrained prosthesis constituted 18%, 8% and 3%, respectively.

CONCLUSION

Cemented TKAs with selective stem extension in patients with SOK had satisfactory implant survivorship and reliable outcomes. Secondary osteonecrosis of the patella should be carefully evaluated prior to operation.

Subchondral Bone Remodeling: A Therapeutic Target for Osteoarthritis

There is emerging awareness that subchondral bone remodeling plays an important role in the development of osteoarthritis (OA). This review presents recent investigations on the cellular and molecular mechanism of subchondral bone remodeling, and summarizes the current interventions and potential therapeutic targets related to OA subchondral bone remodeling. The first part of this review covers key cells and molecular mediators involved in subchondral bone remodeling (osteoclasts, osteoblasts, osteocytes, bone extracellular matrix, vascularization, nerve innervation, and related signaling pathways). The second part of this review describes candidate treatments for OA subchondral bone remodeling, including the use of bone-acting reagents and the application of regenerative therapies. Currently available clinical OA therapies and known responses in subchondral bone remodeling are summarized as a basis for the investigation of potential therapeutic mediators.

Clinical Applicability of Adult Human Mesenchymal Stem Cell Therapy in the Treatment of Knee Osteoarthritis

Introduction

Osteoarthritis causes a progressive deterioration to the protective cartilage between the joints leading to chronic pain and disability. This review focuses on the intrinsic potential of MSCs to stabilize and repair the cartilage tissue of the knee joint in knee osteoarthritis (KOA) patients.

Methods

An online search through the PubMed database was conducted, limiting the search to the English language and human clinical trials within the past 5 years. Twenty-one clinical trials passed the inclusion criteria. Combined, those trials involved the participation of 589 patients where the progress of the treatments was monitored between a 4-month to 7-years period. The cartilage volume and defects were observed through an MRI to provide an objective assessment. While the pain and knee function were monitored using KOOS, VAS, and WOMAC scoring scales providing a subjective assessment.

Results

MRI scans obtained from clinical trials demonstrate a slowed progression of cartilage degeneration and early signs of cartilage regeneration in KOA patients at the 12-month follow-up period. No major adverse effects were observed post-intervention. The overall KOOS, WOMAC, and VAS scores in patients receiving MSC treatment were reduced, suggesting subjective improvements in knee function and pain reduction when compared to patients in the placebo group.

Conclusion

The use of MSC therapy is a valid form of treatment for KOA as it targets the disease itself rather than the symptoms. We found MSC therapy in KOA patients to be safe, effective, and feasible in its execution.

Quantification and Comprehensive Analysis of Mesenchymal Stromal Cells in Bone Marrow Samples from Sickle Cell Disease Patients with Osteonecrosis

The potential use of bone marrow mesenchymal stromal cells (BM-MSCs) for the treatment of osteonecrosis in sickle cell disease (SCD) patients is increasing. However, convenient BM-MSC quantification and functional property assays are critical factors for cell-based therapies yet to be optimized. This study was designed to quantify the MSC population in bone marrow (BM) samples from SCD patients with osteonecrosis (SCD group) and patients with osteoarticular complications not related to SCD (NS group), using flow cytometry for CD271⁺CD45^-/low cell phenotype and CFU-F assay. We also compared expanded BM-MSC osteogenic differentiation, migration, and cytokine secretion potential between these groups. The mean total cell number, CFU-F count, and CD271⁺CD45^-/low cells in BM mononuclear concentrate were significantly higher in SCD than in NS patients. A significant correlation between CD271⁺CD45^-/low cell number and CFU-F counts was found in SCD (r = 0.7483; p = 0.0070) and NS (r = 0.7167; p = 0.0370) BM concentrates. An age-related quantitative reduction of CFU-F counts and CD271⁺CD45^-/low cell number was noted. Furthermore, no significant differences in the morphology, replicative capacity, expression of surface markers, multidifferentiation potential, and secretion of cytokines were found in expanded BM-MSCs from SCD and NS groups after in vitro culturing. Collectively, this work provides important data for the suitable measurement and expansion of BM-MSC in support to advanced cell-based therapies for SCD patients with osteonecrosis.

Initial Presentation and Progression of Secondary Osteonecrosis of the Knee

BACKGROUND

Early detection and intervention are critical to maintaining the native articular cartilage before collapse in secondary osteonecrosis of the knee (SOK). We conducted a retrospective study documenting the initial stage of presentation and the progression of SOK.

METHODS

Our database was reviewed for patients younger than 65 years of age diagnosed with atraumatic SOK between 2002 and 2018. Demographic data, plain radiographs as well as MRI at initial evaluation, and initial treatment were classified and analyzed.

RESULTS

One hundred four patients with 164 knees were identified. Mean age was 39 ± 16 years. Females (64%) with bilateral disease (58%) predominated. Seventy-five percent of patients had a history of corticosteroid use, of which 41% were diagnosed with hematologic malignancy and lupus. Fifteen percent of patients had a history of ethanol abuse. At initial presentation, 55% of patients were diagnosed with Ficat-Arlet stage I/II, while 45% were diagnosed with Ficat-Arlet stage III/IV. We found a significant difference in the mean age of patients at early stage of SOK with corticosteroid use (31 ± 12 years of age) when compared to ethanol use (43 ± 13 years of age, P = .02). Treatments included observation (57%), joint preservation surgery (20%), and total knee arthroplasty (23%).

CONCLUSION

Nearly half of patients presented at late stage compromising the potential for joint preservation. The difference in age of referral by over a decade, based on etiology of SOK, suggests a strong provider-based referral or screening bias may be present. Hence, a multidisciplinary approach to earlier detection and referral may be a more effective strategy for preventing the progression of SOK.

Evaluation of cartilage biomechanics and knee joint microenvironment after different cell-based treatments in a sheep model of early osteoarthritis

PURPOSE

Aiming to prevent cartilage damage during early osteoarthritis (OA), the therapeutic challenge is to restore and maintain the physiological and functional properties of such a tissue with minimally invasive therapeutic strategies.

METHODS

Accordingly, an in vivo model of early OA in sheep was here treated through three different cell therapies (culture expanded ADSCs, SVF, and culture expanded AECs) thus to preserve the joint surface from the progression of the pathology. Three months after the treatment injections, their performance was assessed through mechanical automated mapping (Young's modulus and cartilage thickness), gross evaluation of articular surfaces, and biochemical analysis of the synovial fluid.

RESULTS

No severe degeneration was observed after three months from OA induction. Cartilage mechanical properties were crucial to identify early degeneration. All the treatments improved the macroscopic cartilage surface aspect and reduced pro-inflammatory cytokines in the synovial fluid. Among the three treatments, SVF highlighted the best performance while ADSCs the worst.

CONCLUSION

Despite that the evaluated experimental time is an early follow-up and, thus, longer trial is mandatory to properly assess treatments effectiveness, the proposed multidisciplinary approach allowed to obtain preliminary, but also crucial, results concerning the reduction in OA signs on cartilage properties, in osteophyte development and in all the inflammatory markers.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Subchondral bone or intra-articular injection of bone marrow concentrate mesenchymal stem cells in bilateral knee osteoarthritis: what better postpone knee arthroplasty at fifteen years? A randomized study

PURPOSE

There is an increasing number of reports on the treatment of knee osteoarthritis (OA) using mesenchymal stem cells (MSCs). However, it is not known what would better drive osteoarthritis stabilization to postpone total knee arthroplasty (TKA): targeting the synovial fluid by injection or targeting on the subchondral bone with MSCs implantation.

METHODS

A prospective randomized controlled clinical trial was carried out between 2000 and 2005 in 120 knees of 60 patients with painful bilateral knee osteoarthritis with a similar osteoarthritis grade. During the same anaesthesia, a bone marrow concentrate of 40 mL containing an average 5727 MSCs/mL (range 2740 to 7540) was divided in two equal parts: after randomization, one part (20 mL) was delivered to the subchondral bone of femur and tibia of one knee (subchondral group) and the other part was injected in the joint for the contralateral knee (intra-articular group). MSCs were counted as CFU-F (colony fibroblastic unit forming). Clinical outcomes of the patient (Knee Society score) were obtained along with radiological imaging outcomes (including MRIs) at two year follow-up. Subsequent revision surgeries were identified until the most recent follow-up (average of 15 years, range 13 to 18 years).

RESULTS

At two year follow-up, clinical and imaging (MRI) improvement was higher on the side that received cells in the subchondral bone. At the most recent follow-up (15 years), among the 60 knees treated with subchondral cell therapy, the yearly arthroplasty incidence was 1.3% per knee-year; for the 60 knees with intra-articular cell therapy, the yearly arthroplasty incidence was higher (p = 0.01) with an incidence of 4.6% per knee-year. For the side with subchondral cell therapy, 12 (20%) of 60 knees underwent TKA, while 42 (70%) of 60 knees underwent TKA on the side with intra-articular cell therapy. Among the 18 patients who had no subsequent surgery on both sides, all preferred the knee with subchondral cell therapy.

CONCLUSIONS

Implantation of MSCs in the subchondral bone of an osteoarthritic knee is more effective to postpone TKA than injection of the same intra-articular dose in the contralateral knee with the same grade of osteoarthritis.

Mesenchymal stem cell exosomes in bone regenerative strategies-a systematic review of preclinical studies

The ability of bone for regeneration has long been recognized. However, once beyond a critical size, spontaneous regeneration of bone is limited. Several studies have focused on enhancing bone regeneration by applying mesenchymal stromal/stem cells (MSCs) in the treatment strategies. Despite the therapeutic efficacy of MSCs in bone regeneration, cell-based therapies are impeded by several challenges in maintaining the optimal cell potency and viability during expansion, storage, and final delivery to patients. Recently, there has been a paradigm shift in therapeutic mechanism of MSCs in tissue repair from one based on cellular differentiation and replacement to one based on secretion and paracrine signaling. Among the broad spectrum of trophic factors, extracellular vesicles ​particularly the exosomes have been reported to be therapeutically efficacious in several injury/disease indications, including bone defects and diseases. The current systematic review aims to summarize the results of the existing animal studies which were conducted to evaluate the therapeutic efficacy of MSC exosomes for bone regeneration. Following the Preferred Reporting Items for Systematic Reviews and Meta-analysis ​guidelines, the PubMed and The Cochrane Library database were searched for relevant controlled preclinical animal studies. A total of 23 studies were identified, with the total sample size being 690 rats or mice and 38 rabbits. Generally, MSC exosomes were found to be efficacious for bone regeneration in animal models of bone defects and diseases such as osteonecrosis and osteoporosis. In these studies, MSC exosomes promoted new bone formation with supporting vasculature ​and displayed improved morphological, biomechanical, and histological outcomes, coupled with positive effects on cell survival, proliferation, and migration, osteogenesis, and angiogenesis. Unclear-to-low risk in bias and incomplete reporting in the primary studies highlighted the need for standardization in outcome measurements and reporting. Further studies in large animal models to establish the safety and efficacy would provide useful information on guiding the design of clinical trials.

•

Therapeutic efficacy of MSC exosomes in bone regeneration was studied in 23 studies.

•

MSC exosomes are therapeutically efficacious in bone regeneration.

•

MSC exosomes improve morphological, biomechanical, and histological outcomes.

•

MSC exosomes promote a multifaceted mechanism in bone regeneration.

Human bone marrow mesenchymal stem cell injection in subchondral lesions of knee osteoarthritis: a prospective randomized study versus contralateral arthroplasty at a mean fifteen year follow-up

PURPOSE

Recently, mesenchymal stem cells (MSCs) have been proposed as potential treatment modalities for knee osteoarthritis. However, indications and long-term results have not been frequently reported. The purpose of this study was to determine whether bone marrow lesion on MRI are predictive of risk progression to total knee arthroplasty during the first ten years after subchondral cell therapy.

METHODS

This study included 140 adults aged 65 to 90 years. These 140 patients (mean age 75.4 ± 14.2 years) planned to undergo staged-bilateral total knee arthroplasty (TKA) for medial osteoarthritis, had "comparable" pain in both knees, and accepted randomization of the knees for surgery. They received TKA on one side and a subchondral injection of MSCs (from iliac bone marrow concentrate) on the contralateral knee during the same anaesthetic. The bone marrow graft of 20 cm³ volume (10 cc in the tibia and 10 cc in the femur) contained average 7800 MSCs/mL (range 3120 to 11,560). The baseline volume of bone marrow lesions (BMLs) on the tibia and on the femoral condyle determined on MRI was average 3.4 cm³ (range 0.4 to 6.4 cm³). The risk of subsequent knee arthroplasty due to absence of bone marrow lesions regression as well as osteoarthritis (OA) grade was evaluated with Cox proportional-hazards ratio after control of baseline variables (number of cells injected, age, knee alignment).

RESULTS

After treatment with MSCs injection in bone marrow lesions of the subchondral bone, medial femorotibial compartment BML volume experienced regression over 24 months (mean regression 1.5 cm³, range 0.8 to 3.2 cm³). At the most recent follow up (average of 15 years, range 10 to 20 years), a total of 25 (18%) of the 140 patients underwent total knee arthroplasty performed at a mean of ten years (range, 5 to 15 years) after the date of the cell therapy. The overall incidence of knee arthroplasty after cell therapy was 1.19% per person-year which was equivalent to the risk of a revision for a primary TKA in the contralateral knees of the same patient population (21 revisions, corresponding to 1.00% revision per person-year; p = 0.34). After adjusting for confounders, persistent BMLs larger than 3 cm³ after cell therapy was a strong independent risk factor for total knee arthroplasty (hazard ratio HR = 4.42 [95% CI = 2.34 to 7.21]; p < 0.001), regardless of OA grade, with higher risks demonstrated for larger BMLs. Incidence rates of arthroplasty were also higher for young patients and for knees presenting severe malalignment.

CONCLUSIONS

This study showed that subchondral bone marrow concentrate (as compared with TKA) had a sufficient effect on pain to postpone or avoid the TKA in the contra lateral joint of patients with bilateral osteoarthritis. Bone marrow lesions were predictive factors for future knee arthroplasty in the knee with subchondral cell therapy at ten years follow-up.

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

Background

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

Methods

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

Results

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

Conclusions

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

Prevention of post-traumatic osteoarthritis after intra-articular knee fractures using hyaluronic acid: a randomized prospective pilot study

PURPOSE

Based on the irreversible destruction of hyaline cartilage, post-traumatic osteoarthritis (PTOA) is a notorious sequelae after intra-articular knee fractures. This study evaluates the clinical efficacy and applicability of immediate post-operative intra-articular injection of hyaluronic acid (IA HA) into the knee joint with an intra-articular fracture.

METHODS

Prospective randomized case-control study involving 40 patients (20 in each group) with intra-articular knee fracture with an average follow-up of 23 months (range 18-24 months). Twenty patients with intra-articular distal femoral or intra-articular proximal tibial fractures who met our inclusion criteria received three intra-articular hyaluronic acid injections weekly starting immediately after ORIF. Another 20 patients serving as a control group received no injection after ORIF. Patients were assessed functionally with Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) score. Plain X-rays and when indicated CT scans were used to assess radiological union.

RESULTS

The results showed patients treated with intra-articular hyaluronic acid injection after fixation had significantly less pain (KOOS) (p = 0.01). No significant difference was found between both groups in other KOOS-related outcome measures, complications, functional outcome, or quality of life.

CONCLUSIONS

These preliminary results support a direct role for hyaluronic acid in the acute phase of the inflammatory process that follows articular injury and provides initial evidence for the efficacy of IA HA.

Vitamin D history part III: the "modern times"-new questions for orthopaedic practice: deficiency, cell therapy, osteomalacia, fractures, supplementation, infections

PURPOSE

The nutritional basis for rickets was described between 1880 and 1915, at the same period of discovery of other "vital substances" or vitamins. In contrast, rickets could also be prevented or cured by sunshine. But as the capacity to produce vitamin D depends on exposure to ultraviolet B rays (UVB) from sunlight or artificial sources, vitamin D became one of the most frequently used "drugs" in the twentieth century to compensate for insufficient exposure to UVB of humans. Furthermore, as the understanding of vitamin D metabolism grew during the twentieth century, other concerns than rickets occurred for the orthopaedic surgeon: In recent history, deficiency is explored as being an associated factor of different bone pathologies as fracture or prosthetic infection. The aim of this review is to analyze these new data on vitamin D.

MATERIALS AND METHODS

During the twentieth century, there were many concerns for the orthopaedic surgeon: sources and synthesis of vitamin D, regulation of the calcium deposition process for both children and adults, when vitamin D deficiency is observed, and what the best method of vitamin D supplementation is. As target genes regulated by vitamin D are not limited to those involved in mineral homeostasis, orthopedists recently discovered that vitamin D might prevent periprosthetic infection.

RESULTS

The primary source (80%) of vitamin D is dermal synthesis related to the sun. Dietary sources (20%) of vitamin D are fat fishe, beef, liver, and eggs. Vitamin D is produced industrially to be used in fortified foods and supplements. Maintenance of skeletal calcium balance is mediated through vitamin D receptors. Progenitor cells, chondrocytes, osteoblasts, and osteoclasts contain these receptors which explains the role of vitamin D in cell therapy, in the prevention of rickets and osteomalacia. Despite fortified foods, the prevalence of deficiency remains endemic in north latitudes. However, the definition of vitamin D insufficiency or deficiency remains controversial. Vitamin D has been evaluated in patients undergoing fractures and elective orthopaedic procedures Although supplementation may not be able to prevent or cure all the orthopaedic pathologies, oral supplementation is able to improve the vitamin D levels of deficient patients. These vitamin D level improvements might be associated with better functional and clinical outcomes after some surgical procedures and improvement of immunity to decrease the risk of infection in arthroplasties.

CONCLUSION

Vitamin D deficiency is frequent and concerns millions of people in the world. It is therefore normal to find hypovitaminosis in various orthopaedic populations including trauma and arthroplasties. However, we do not know exactly if this phenomenon only reflects the general prevalence of vitamin D deficiency or has an influence on the outcome of some pathologies on specific populations at risk. After the success of treatment of rickets, it is disappointing that we are still wondering in the twenty-first century whether supplementation of a substance synthetized millions of years ago by plankton and necessary for growth of all the animals may improve (or not) clinical and functional outcomes of a simple fracture in humans.

Concentrated adipose tissue infusion for the treatment of knee osteoarthritis: clinical and histological observations

PURPOSE

Osteoarthritis (OA) is characterized by articular cartilage degeneration and subchondral bone sclerosis. OA can benefit of non-surgical treatments with collagenase-isolated stromal vascular fraction (SVF) or cultured-expanded mesenchymal stem cells (ASCs). To avoid high manipulation of the lipoaspirate needed to obtain ASCs and SVF, we investigated whether articular infusions of autologous concentrated adipose tissue are an effective treatment for knee OA patients.

METHODS

The knee of 20 OA patients was intra-articularly injected with autologous concentrated adipose tissue, obtained after centrifugation of lipoaspirate. Patients' articular functionality and pain were evaluated by VAS and WOMAC scores at three, six and 18 months from infusion. The osteogenic and chondrogenic ability of ASCs contained in the injected adipose tissue was studied in in vitro primary osteoblast and chondrocyte cell cultures, also plated on 3D-bone scaffold. Knee articular biopsies of patients previously treated with adipose tissue were analyzed. Immunohistochemistry (IHC) and scanning electron microscopy (SEM) were performed to detect cell differentiation and tissue regeneration.

RESULTS

The treatment resulted safe, and all patients reported an improvement in terms of pain reduction and increase of function. According to the osteogenic or chondrogenic stimulation, ASCs expressed alkaline phosphatase or aggrecan, respectively. The presence of a layer of newly formed tissue was visualized by IHC staining and SEM. The biopsy of previously treated knee joints showed new tissue formation, starting from the bone side of the osteochondral lesion.

CONCLUSIONS

Overall our data indicate that adipose tissue infusion stimulates tissue regeneration and might be considered a safe treatment for knee OA.