Aragonite-Based Scaffold for the Treatment of Joint Surface Lesions in Mild to Moderate Osteoarthritic Knees: Results of a 2-Year Multicenter Prospective Study

A Biomimetic Osteochondral Scaffold Augmented With Filtered Bone Marrow Aspirate for the Treatment of Joint Surface Lesions in the Knee

BACKGROUND

Multilayered osteochondral scaffolds are becoming increasingly utilized for the repair of knee joint surface lesions (KJSLs). However, the literature on predictive factors is rather limited.

PURPOSE

To (1) evaluate the clinical outcomes and safety of a combined single-step approach using a biomimetic collagen-hydroxyapatite scaffold (CHAS) and filtered bone marrow aspirate (fBMA) for the treatment of KJSLs and (2) identify significant predictors of the treatment outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients who underwent surgery because of a KJSL (size ≥1.5 cm2; International Cartilage Regeneration & Joint Preservation Society grades 3-4) using the combination above were selected from a hospital registry database (100 patients; minimum 2-year follow-up). Patient characteristics, medical history, knee joint and lesion status, intraoperative details, and cellular parameters of the injected fBMA were collected. The arthroscopic evaluation of chondral and meniscal tissue quality in all knee compartments was performed using the Chondropenia Severity Score. Treatment outcomes were determined clinically using patient-reported outcome measures (Knee Injury and Osteoarthritis Outcome Score, EuroQol-5 Dimensions-3 Levels, EuroQol-Visual Analog Scale, and Tegner Activity Scale) and by assessing the occurrence of serious adverse events and graft failure. Multivariable regression analysis was performed to identify significant predictors of the treatment outcomes.

RESULTS

At a mean follow-up of 54.2 ± 19.4 months, 78 (87%) patients completed the questionnaires with significant improvements toward the baseline (P < .00625): KOOS Pain subscale from 62 ± 17 to 79 ± 18, KOOS Total score from 57 ± 16 to 70 ± 20, EuroQol-Visual Analog Scale from 61 ± 21 to 76 ± 16, EuroQol-5 Dimensions-3 Levels from 0.57 ± 0.20 to 0.80 ± 0.21, and Tegner Activity Scale from 2.8 ± 1.5 to 3.9 ± 1.9. The graft failure rate was 4%. A longer duration of preoperative symptoms, previous surgery, larger lesions, older age, and female sex were the main negative predictors for the treatment outcomes. The Chondropenia Severity Score and the number of fibroblast colony-forming units in fBMA positively influenced some of the clinical results and safety.

CONCLUSION

A CHAS augmented with fBMA proved to be an adequate and safe approach for the treatment of KJSLs up to midterm follow-up. Based on the subanalysis of predictive factors, the surgical intervention should be performed in a timely and precise manner to prevent lesion enlargement, deterioration of the general knee cartilage status, and recurrent surgical procedures, especially in older and female patients. When a CHAS is used, the quantity of MSCs seems to play a role in augmentation.

REGISTRATION

NCT06078072 (ClinicalTrials.gov identifier).

Unicompartmental osteoarthritis: High survival rate with a combined mechanical and biological salvage approach as alternative to metal resurfacing: Results at minimum 10 years of follow-up

PURPOSE

The aim of this study was to prospectively evaluate the long-term clinical results and failure rate of patients treated with complex salvage procedures using a combined mechanical and biological approach to address unicompartmental knee osteoarthritis (OA) and postpone the need for joint replacement.

METHODS

Thirty-nine patients (40.3 ± 10.9 years old) affected by unicompartmental OA (Kellgren-Lawrence 3) in stable joints underwent a personalized surgical treatment depending on the specific requirements of the affected compartment, including high tibial osteotomy, osteochondral scaffold, meniscal scaffold and meniscal allograft transplantation. Patients were evaluated with the International Knee Documentation Committee (IKDC), Visual Analogue Scale (VAS) and Tegner scores before surgery, at 3 years and a minimum of 10 years of follow-up.

RESULTS

A significant improvement was observed over time in all scores but worsened at the final follow-up. The IKDC subjective score improved from 46.9 ± 16.2 to 79.8 ± 16.4 at 3 years (p < 0.0005) and then decreased to 64.5 ± 21.4 (p = 0.001) at 12 years. A similar trend was confirmed for VAS and Tegner scores. Only two patients subsequently underwent knee arthroplasty, and nine more patients were considered clinical failure, for a cumulative surgical and clinical failure rate of 28.2% at the final follow-up.

CONCLUSION

A personalized, joint-preserving, combined mechanical and biological approach, addressing alignment as well as meniscal and cartilage lesions, is safe and effective, providing a clinical benefit and delaying the need for arthroplasty in young patients affected by unicompartmental knee OA. At the final evaluation, the clinical improvement decreased, but more than two-thirds of the patients still benefited from this treatment at a long-term follow-up.

LEVEL OF EVIDENCE

Level IV case series.

Acellular Aragonite-Based Scaffold for the Treatment of Joint Surface Lesions of the Knee: A Minimum 5-Year Follow-Up Study

OBJECTIVE

A novel aragonite-based scaffold has been developed. In this study, mid-term clinical and magnetic resonance imaging (MRI) results on 12 patients affected by isolated chondral or osteochondral lesions of the knee treated by the scaffold implantation have been evaluated at a mean follow-up of 6.5 (range: 5-8) years.

DESIGN

The study population consisted of 3 females and 9 males, mean age 34.4 (20-51) years. The lesion was located on the medial femoral condyle, the trochlea, and the lateral femoral condyle in 5, 5, and 2 patients, respectively. In all cases, a single lesion over grade 3 of the International Cartilage Restoration and Joint Preservation Society (ICRS) classification was treated: in 9 cases by implantation of one plug, and in 2 cases with 2 plugs; the mean size of the lesion was 2.5 cm2 (1-7).

RESULTS

One patient failed and was revised with a custom-made metal implant (Episealer). Overall, Knee Injury and Osteoarthritis Outcome Score (KOOS) significantly improved from 45 ± 13 preoperatively to 86 ± 13 at final follow-up. All KOOS subscales improved significantly: pain subscale increased from 48 ± 12 to 92 ± 11; symptoms from 66 ± 13 to 91 ± 13; activity of daily living (ADL) from 60 ± 19 to 90 ± 21; sport from 23 ± 20 to 75 ± 20; finally, quality of life (QoL) increased from 27 ± 14 to 77 ± 19. Long-term MRI MOCART score was 64.

CONCLUSIONS

This study shows continued significant clinical improvement and good magnetic resonance imaging (MRI) findings with a minimum 5 years follow-up after implantation of a novel aragonite derived scaffold for the treatment of cartilage lesions of the knee. One patient failed and was revised with a custom-made metal implant (Episealer).

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.

Multiphasic scaffolds for the repair of osteochondral defects: Outcomes of preclinical studies

Osteochondral defects are caused by injury to both the articular cartilage and subchondral bone within skeletal joints. They can lead to irreversible joint damage and increase the risk of progression to osteoarthritis. Current treatments for osteochondral injuries are not curative and only target symptoms, highlighting the need for a tissue engineering solution. Scaffold-based approaches can be used to assist osteochondral tissue regeneration, where biomaterials tailored to the properties of cartilage and bone are used to restore the defect and minimise the risk of further joint degeneration. This review captures original research studies published since 2015, on multiphasic scaffolds used to treat osteochondral defects in animal models. These studies used an extensive range of biomaterials for scaffold fabrication, consisting mainly of natural and synthetic polymers. Different methods were used to create multiphasic scaffold designs, including by integrating or fabricating multiple layers, creating gradients, or through the addition of factors such as minerals, growth factors, and cells. The studies used a variety of animals to model osteochondral defects, where rabbits were the most commonly chosen and the vast majority of studies reported small rather than large animal models. The few available clinical studies reporting cell-free scaffolds have shown promising early-stage results in osteochondral repair, but long-term follow-up is necessary to demonstrate consistency in defect restoration. Overall, preclinical studies of multiphasic scaffolds show favourable results in simultaneously regenerating cartilage and bone in animal models of osteochondral defects, suggesting that biomaterials-based tissue engineering strategies may be a promising solution.

Adaptive enhancement design of non-significant regions of a Wushu action 3D image based on the symmetric difference algorithm

The recognition of martial arts movements with the aid of computers has become crucial because of the vigorous promotion of martial arts education in schools in China to support the national essence and the inclusion of martial arts as a physical education test item in the secondary school examination in Shanghai. In this paper, the fundamentals of background difference algorithms are examined and a systematic analysis of the benefits and drawbacks of various background difference algorithms is presented. Background difference algorithm solutions are proposed for a number of common, challenging problems. The empty background is then automatically extracted using a symmetric disparity approach that is proposed for the initialization of background disparity in three-dimensional (3D) photos of martial arts action. It is possible to swiftly remove and manipulate the background, even in intricate martial arts action recognition scenarios. According to the experimental findings, the algorithm's optimized model significantly enhances the foreground segmentation effect of the backdrop disparity in 3D photos of martial arts action. The use of features such as texture probability is coupled to considerably enhance the shadow elimination effect for the shadow problem of background differences.

Aragonite-Based Scaffold Versus Microfracture and Debridement for the Treatment of Knee Chondral and Osteochondral Lesions: Results of a Multicenter Randomized Controlled Trial

BACKGROUND

Lesions of the articular cartilage, with or without involvement of the subchondral bone, are a common cause of pain and dysfunction in the knee. Although several treatment options have been developed, the majority of previous clinical trials examined patients with isolated or focal midsized defects, which rarely represent the condition found in the general population. Rather, cartilage lesions are often associated with the presence of mild to moderate osteoarthritic changes.

PURPOSE

The present multicenter randomized controlled trial compared the clinical and radiographic outcomes of an aragonite-based osteochondral implant with a control group (arthroscopic debridement/microfractures) in patients affected by joint surface lesions of the knee, including those with concurrent mild to moderate osteoarthritis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 251 patients were enrolled in 26 medical centers according to the following criteria: age 21 to 75 years, up to 3 cartilage defects of International Cartilage Regeneration & Joint Preservation Society grade 3a or above located on the femoral condyles and/or trochlea, total treatable area from 1 to 7 cm², bony defect depth ≤8 mm, and knee osteoarthritis grade 0 to 3 according to Kellgren-Lawrence score. Patients were randomized to the aragonite-based implant or debridement/microfracture control arm in a 2:1 ratio. Evaluation was performed at 6, 12, 18, and 24 months based on overall Knee injury and Osteoarthritis Outcome Score (KOOS) as the primary endpoint, and the KOOS subscales (Pain, Quality of Life, Activities of Daily Living), percentage of responders, and International Knee Documentation Committee (IKDC) subjective score as the secondary endpoints. Patients also underwent magnetic resonance imaging evaluation at 12 and 24 months to assess defect fill grade. Failures (ie, need for any secondary treatment) and adverse events were also recorded.

RESULTS

The implant group showed a statistically superior outcome in the primary endpoint and all secondary endpoints at each follow-up. The magnitude of improvement in the implant group was twice as large as that in the control group in terms of mean KOOS improvement at 2 years. Responder rate (defined as at least a 30-point improvement in overall KOOS) was 77.8% in the implant group as opposed to 33.6% in the control (P < .0001). Statistically superior results were seen in the IKDC score as well. At 24 months, 88.5% of the implanted group had at least 75% defect fill on magnetic resonance imaging as compared with 30.9% of controls (P < .0001). The failure rate was 7.2% for the implant group versus 21.4% for control.

CONCLUSION

This aragonite-based scaffold was safe and effective in the treatment of chondral and osteochondral lesions in the knee, including patients with mild to moderate osteoarthritis, and provided superior outcomes as compared with the control group.

REGISTRATION

NCT03299959 (ClinicalTrials.gov identifier).

Multilayered biomimetic scaffolds for cartilage repair of the talus. A systematic review of the literature

OBJECTIVE

The aim of the present review was to analyze the available evidence in the literature on the clinical and radiological outcomes of multilayered biomimetic scaffolds in the treatment of osteochondral lesions of the talus (OLTs).

DESIGN

A systematic search was performed in three databases to identify clinical trials, where the multilayered biomimetic scaffolds were used for the treatment of OLTs. The PRISMA guidelines were followed. Qualitative analysis of the relevant data of the included studies was executed. The methodological quality of the analyzed studies was assessed with a modified Coleman Methodology Score (CMS).

RESULTS

A total of 10 studies with 87 patients were included in the analysis. Only three multilayered biomimetic scaffolds have been investigated in clinical trials for the treatment of OLTs. The worst clinical and radiological outcomes, as well as safety profile were observed for the TruFit scaffold (Smith & Nephew, Andover, MA, USA), which had already been withdrawn from the market. The other two scaffolds (MaioRegen, Finceramica, Italy; Agili-C, Cartiheal, Israel) performed significantly better in the majority of the reviewed studies, especially in the clinical aspect. The radiological findings, the improvements of MOCART scores, the completeness of lesions' fill, and the structure of regenerated tissue were much more inconsistent.

CONCLUSIONS

Two of the multilayered biomimetic scaffolds demonstrated an adequate potential in the treatment of complex OLTs. However, limited studies availability and their low level of medical evidence request further high-level investigations before the clinical decision making for such scaffolds in the treatment of OLTs can be defined.

Cellular therapy and tissue engineering for cartilage repair

Articular cartilage (AC) has limited capacity for repair. The first attempt to repair cartilage using tissue engineering was reported in 1977. Since then, cell-based interventions have entered clinical practice in orthopaedics, and several tissue engineering approaches to repair cartilage are in the translational pipeline towards clinical application. Classically, these involve a scaffold, substrate or matrix to provide structure, and cells such as chondrocytes or mesenchymal stromal cells to generate the tissue. We discuss the advantages and drawbacks of the use of various cell types, natural and synthetic scaffolds, multiphasic or gradient-based scaffolds, and self-organizing or self-assembling scaffold-free systems, for the engineering of cartilage constructs. Several challenges persist including achieving zonal tissue organization and integration with the surrounding tissue upon implantation. Approaches to improve cartilage thickness, organization and mechanical properties include mechanical stimulation, culture under hypoxic conditions, and stimulation with growth factors or other macromolecules. In addition, advanced technologies such as bioreactors, biosensors and 3D bioprinting are actively being explored. Understanding the underlying mechanisms of action of cell therapy and tissue engineering approaches will help improve and refine therapy development. Finally, we discuss recent studies of the intrinsic cellular and molecular mechanisms of cartilage repair that have identified novel signals and targets and are inspiring the development of molecular therapies to enhance the recruitment and cartilage reparative activity of joint-resident stem and progenitor cells. A one-fits-all solution is unrealistic, and identifying patients who will respond to a specific targeted treatment will be critical.

Study on feasibility of the partial meniscal allograft transplantation

Since the meniscus is an important stabilizing structure of the knee joint and has a significant role in load-bearing and shock absorption, so the complete structural and functional reconstructions of the teared menisci should be done not only after partial meniscectomy but also post total meniscectomy. So far, animal experiments and good clinical practice have showed that TMAT after total meniscectomy has partially solved the problem of structural and functional reconstructions after total meniscectomy. However, partial meniscectomy will also lead to accelerated knee degeneration, and its proportion is much higher than that of patients with total meniscectomy. Herein, the feasibility of PMAT after partial meniscectomy was investigated for the first time by using the 40% posterior horn meniscectomy model of the medial meniscus in Beagle dogs, and also for the first time, TMAT group and the total meniscectomy group were used as control groups. Compared with the TMAT, the transcriptomics evaluation, scanning electron microscope observation, histological regeneration and structure, biomechanical property, inflammation environment, and the knee function post PMAT were more similar to that of normal meniscus was first reported. This study provides a PMAT scheme with clinical translational value for the complete structural and functional reconstruction of the patients with partial meniscectomy and fills the gap in the field of teared meniscus therapy on the basis of quite well clinical applications of the meniscus repair and the TMAT.

Potential New Treatments for Knee OA: A Prospective Review of Registered Trials

We aimed to evaluate potential new treatments for knee osteoarthritis (OA). The National Institute of Health ClinicalTrials.gov database was searched for “Osteoarthritis, Knee”. We found 565 ongoing interventional studies with a total planned enrollment of 111,276 subjects. Ongoing studies for knee OA represent a very small fraction of the registered clinical trials, but they are over a quarter of all knee trials and over two thirds of all OA studies. The most researched topic was arthroplasty, with aspects such as implant design changes, cementless fixation, robotic guidance, pain management, and fast track recovery. Intraarticular injections focused on cell therapies with mesenchymal stem cells sourced from adipose tissue, bone marrow, or umbilical cord. We could see the introduction of the first disease modifying drugs with an impact on knee OA, as well as new procedures such as geniculate artery embolization and geniculate nerve ablation.

Methods of Modification of Mesenchymal Stem Cells and Conditions of Their Culturing for Hyaline Cartilage Tissue Engineering

The use of mesenchymal stromal cells (MSCs) for tissue engineering of hyaline cartilage is a topical area of regenerative medicine that has already entered clinical practice. The key stage of this procedure is to create conditions for chondrogenic differentiation of MSCs, increase the synthesis of hyaline cartilage extracellular matrix proteins by these cells and activate their proliferation. The first such works consisted in the indirect modification of cells, namely, in changing the conditions in which they are located, including microfracturing of the subchondral bone and the use of 3D biodegradable scaffolds. The most effective methods for modifying the cell culture of MSCs are protein and physical, which have already been partially introduced into clinical practice. Genetic methods for modifying MSCs, despite their effectiveness, have significant limitations. Techniques have not yet been developed that allow studying the effectiveness of their application even in limited groups of patients. The use of MSC modification methods allows precise regulation of cell culture proliferation, and in combination with the use of a 3D biodegradable scaffold, it allows obtaining a hyaline-like regenerate in the damaged area. This review is devoted to the consideration and comparison of various methods used to modify the cell culture of MSCs for their use in regenerative medicine of cartilage tissue.

Multi-layer cell-free scaffolds for osteochondral defects of the knee: a systematic review and meta-analysis of clinical evidence

Purpose

The aim of this study was to analyze the clinical results provided by multi-layer cell-free scaffolds for the treatment of knee osteochondral defects.

Methods

A systematic review was performed on PubMed, Web of Science, and Cochrane to identify studies evaluating the clinical efficacy of cell-free osteochondral scaffolds for knee lesions. A meta-analysis was performed on articles reporting results of the International Knee Documentation Committee (IKDC) and Tegner scores. The scores were analyzed as improvement from baseline to 1, 2, and ≥ 3 years of follow-up. The modified Coleman Methodology Score was used to assess the study methodology.

Results

A total of 34 studies (1022 patients) with a mean follow-up of 35 months was included. Only three osteochondral scaffolds have been investigated in clinical trials: while TruFit® has been withdrawn from the market for the questionable results, the analysis of MaioRegen and Agili-C™ provided clinical improvements at 1, 2, and ≥ 3 years of follow-up (all significantly higher than the baseline, p < 0.05), although with a limited recovery of the sport-activity level. A low rate of adverse events and an overall failure rate of 7.0% were observed, but the overall evidence level of the available studies is limited.

Conclusions

Multi-layer scaffolds may provide clinical benefits for the treatment of knee osteochondral lesions at short- and mid-term follow-up and with a low number of failures, although the sport-activity level obtained seems to be limited. Further research with high-level studies is needed to confirm the role of multi-layer scaffold for the treatment of knee osteochondral lesions.

Editorial Commentary: Minimally Invasive Strategies for Osteoarthritis: From Platelets to Mesenchymal Stem Cells

The range of biological agents to treat osteoarthritis is in constant expansion, and recent trials suggest that amnion-derived products (such as umbilical cord stem cells or amniotic allograft suspension) may provide significant symptomatic relief and functional improvement compared with traditional injectables. Anyway, in many countries, stringent limitations exist on the manipulation and homologous use of placenta-derived products, and therefore, collecting more data is mandatory to endorse their use for musculoskeletal diseases in a safe and clearly regulated way. More in general, an increasing interest toward orthobiology has been observed in recent years, which led to the introduction in clinical practice of many minimally invasive strategies to treat osteoarthritis, from platelet-rich plasma to mesenchymal stem cells. On the basis of this trend, which involves physicians from different specialties, it would be fundamental to have clear guidelines establishing the correct use of these products in the setting of clinical routine not only to safely provide patients the most advanced therapeutic options but also to protect our practice from potential legal issues.