Scaffolds for Knee Chondral and Osteochondral Defects: Indications for Different Clinical Scenarios. A Consensus Statement

Report on Evolving Indications, Techniques, and Outcome of Novel and Innovative Surgical procedure - Agili C®

BACKGROUND

Purpose of review Agili-C® (CartiHeal, Smith & Nephew) is an off-the-shelf aragonite-based (inorganic calcium carbonate) scaffold approved for clinical use in 2022 to treat chondral and osteochondral lesions eventually also in the context of mild to moderate knee osteoarthritis (Kellgren-Lawrence 0-3). The successful preclinical studies justified the subsequent clinical trials which reported both clinical and radiological significant improvements over time as well as superiority over standard surgical techniques for cartilage lesions treatment (i.e. microfractures/debridement). The aim of the present review is to summarize the available preclinical and clinical evidence and to report the current indications, surgical techniques and outcomes of this novel and innovative osteochondral scaffold.

RECENT FINDINGS

A total of six clinical reports, four single cohorts studies and a recent double arm randomized control trial followed by an analysis differentiating between femoral and trochlear lesions, have been published on Agili-C® safety and efficacy. Supported with an excellent safety profile, Agili-C® provided statistically significant clinical benefits at short and medium-term follow up in patients affected by knee joint surface lesions also when presenting in the context of mild to moderate knee osteoarthritis (Kellgren-Lawrence 0-3). Agili-C® (CartiHeal, Smith & Nephew) is an innovative aragonite-based osteochondral scaffold. It is an CE-marked and FDA approved off-the-shelf, cell-free, and cost-effective implant designed to treat knee joint surface lesions in the form of chondral and osteochondral defects. Its indications, supported by consistent clinical evidence, are single or multiple knee joint surface lesions (ICRS grade III or IV), with a total treatable area of 1-7cm2, without severe knee OA (Kellgren-Lawrence grade 0-3).

Female patients report comparable results to males after the implantation of an aragonite-based scaffold for the treatment of knee chondral and osteochondral defects: a gender-based analysis of a RCT at 4 years' follow-up

BACKGROUND

The aim of the study was to provide a gender-based analysis of the results of a large, multi-centre randomized controlled trial (RCT) comparing a novel cell-free aragonite-based scaffold with the standard of care (i.e. debridement/microfractures) for the treatment of chondral/osteochondral defects in knees with or without concurrent osteoarthritis.

MATERIALS AND METHODS

A total of 251 patients were included: 167 patients in the scaffold group and 84 in the control. In the scaffold group, there were 105 males and 59 females, whereas the control group consisted of 51 males and 32 females. Patients were evaluated up to 48 months after the treatment. The primary endpoint was the change from baseline to 48 months in the KOOS overall score. Treatment failures were defined as any secondary invasive intervention, including intra-articular injection or any surgery in the treated joint. All patients underwent magnetic resonance imaging (MRI) at 12 and 24 months to assess the percentage of defect fill after surgery.

RESULTS

Both males and females in the scaffold group achieved significantly better results than controls in any KOOS subscale, as well as in KOOS overall, up to the final 48 months follow-up. Outcomes reported by females were non-inferior to those of males in the implant group. At 24 months' MRI evaluation, 86.2% of male patients in the scaffold group presented at least 75% defect fill compared with 32.6% in the control group. In the scaffold group, 87.6% of female patients presented at least 75% defect fill, compared with 28% in the control group (p < 0.0001 in both cases). Responders' rate and failure rate were also significantly better in the scaffold group for both males and females.

CONCLUSION

The aragonite scaffold outperformed the control group at 48 months' evaluation. The gender-based analysis proved that males and females in the scaffold group presented comparable clinical and radiographical results, both significantly better than their counterparts treated by debridement/microfractures.

LEVEL OF EVIDENCE

I-Randomized controlled trial.

TRIAL REGISTRATION

Clinicaltrial.gov ID: NCT03299959 (registered on 14 September 2017).

Knee Cartilage Injuries in Football Players: Clinical Outcomes and Return to Sport After Surgical Treatment: A Systematic Review of the Literature

OBJECTIVE

To systematically review the literature and analyze clinical outcomes and return-to-sport after surgical management of cartilage injuries in football players.

DESIGN

A systematic literature review was performed in August 2023 on PubMed, WebOfScience, and Cochrane Library to collect studies on surgical strategies for cartilage lesions in football players. Methodological quality and risk of bias were assessed with the modified Coleman Methodology score and RoB2 and RoBANS2 tools.

RESULTS

Fifteen studies on 409 football players (86% men, 14% women) were included: nine prospective and two retrospective case series, one randomized controlled trial, one prospective comparative study, one case report, and one survey. Bone marrow stimulation (BMS) techniques were the most documented. The lesion size influenced the treatment choice: debridement was used for small lesions (1.1 cm2), BMS, osteochondral autograft transplantation (OAT), matrix-assisted autologous chondrocytes transplantation (MACT), and scaffold-augmented BMS for small/mid-size lesions (2.2-3.0 cm2), and autologous chondrocytes implantation (ACI) for larger lesions (5.8 cm2). The surgical options yielded different results in terms of clinical outcome and return-to-sport, with fastest recovery for debridement and scaffold-augmented BMS. The current evidence is limited with large methodological quality variation (modified Coleman Methodology score 43.5/100) and a high risk of bias.

CONCLUSIONS

Decision-making in cartilage injuries seems to privilege early return-to-sport, making debridement and microfractures the most used techniques. The lesion size influences the treatment choice. However, the current evidence is limited. Further studies are needed to confirm these findings and establish a case-based approach to treat cartilage injuries in football players based on the specific patient and lesion characteristics and the treatments' potential in terms of both return-to-sport and long-term results.

LEVEL OF EVIDENCE

Systematic review, level IV.

Arthroscopic Implantation of a Cell-Free Bilayer Scaffold for the Treatment of Knee Chondral Lesions: A 2-Year Prospective Study

OBJECTIVE

The main objective of this study is to assess the safety and clinical efficacy of a cell-free bilayer scaffold (MaioRegen Chondro+ by Fin-Ceramica) in patients affected by chondral knee lesions of different origin and localization.

DESIGN

Thirty-one patients with focal chondral lesions of the knee were arthroscopically treated with MaioRegen Chondro+. All patients were prospectively evaluated for a minimum of 2 years using the International Knee Documentation Committee (IKDC) Questionnaire and the Tegner Activity Scale. Cartilage repair was assessed based on the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score at 12 months. Follow-up at 36 months was available for 25 out of 31 patients.

RESULTS

From baseline to 6-, 12-, and 24-month follow-up, IKDC score significantly improved by 19.5 ± 7.27 (95% confidence interval [CI]: 16.9-22.2, P < 0.001), 30.8 ± 7.63 (95% CI: 28.0-33.6, P < 0.001), and 36.2 ± 8.00 points (95% CI: 33.3-39.2, P < 0.001), respectively. Tegner scores documented a substantial clinical improvement as early as 12 months after surgery (change of -0.6 ± 0.62; 95% CI: -0.8 to -0.4, P < 0.001), reaching the preinjury values. There was a statistically significant increase in the MOCART scores (P < 0.001). Comparable results were observed regardless of preintervention demographic characteristics, lesion site or etiology, or the number of treated sites. Notably, the significant clinical benefit was maintained in a subset of patients who reached 3-year follow-up. No adverse events were reported in the entire analyzed population.

CONCLUSION

MaioRegen Chondro+ is a safe and effective device for the treatment of knee chondral lesions, enabling a significant clinical improvement for at least 2 years.

Patellofemoral joint including patellar instability part 3 (Patellofemoral cartilage treatment): State of the art

Cartilage lesions around the knee are common injuries in the orthopedic practice. The spontaneous healing capacity of the articular cartilage is limited, and therefore surgical intervention may be necessary. The goal is to improve patients' symptoms, articular functionality, and potentially delay the progression of knee osteoarthritis. Extensive knowledge is available regarding the efficacy of cartilage restoration procedures for tibiofemoral chondral and osteochondral lesions; however, evidence on patellofemoral surgery remains more limited and controversial. The complex biomechanics and morphology of the patellofemoral joint represents a challenge in the setting of knee cartilage surgery and, as a result, inferior outcomes have been reported when compared to treatment of condylar lesions. Furthermore, patellofemoral cartilage restoration can be combined with procedures such as a tibial tuberosity osteotomy and/or other realigning osteotomies when pathological deformities are present. Finally, when the aforementioned strategies fail or when severe osteoarthritis develops, and preservation procedures are contraindicated, arthroplasty and other options can be considered. This State of the Art review aims to critically examine the current concepts of conservative and surgical treatment of patellofemoral cartilage lesions, reporting the latest clinical evidence and describing potential future perspectives in this field.

Cell-free biomimetic osteochondral scaffold for the treatment of knee articular surface lesions: Clinical outcomes differ based on patient and lesion characteristics

PURPOSE

A cell-free biomimetic osteochondral scaffold was developed to treat cartilage knee lesions, with positive clinical results documented in small case series. However, clear evidence on patient and lesion characteristics that might affect the outcome is still lacking. The aim of this study is to analyse a large cohort of patients treated with this scaffold to investigate factors that could influence the clinical outcome.

METHODS

Two hundred and three patients (mean age 30.7 ± 10.9 years) treated with this scaffold were prospectively evaluated at baseline, 6-, 12- and 24-month follow-up. The clinical outcome was analysed using the International Knee Documentation Committee (IKDC) score, and the activity level was assessed with the Tegner score. The influence of patient and lesion characteristics on clinical outcomes was analysed.

RESULTS

Mild and severe adverse reactions were found in 39.0% and 1.5% of patients, respectively. The failure rate was 2.0%, increasing to 12.3% when including also clinical failures. The IKDC subjective score increased from 43.3 ± 15.9 to 61.0 ± 16.2 at 6 months, 68.3 ± 18.5 at 12 months and 73.8 ± 18.3 at 24 months (p < 0.0005). The Tegner improved from 2.5 ± 1.7 to 4.2 ± 1.7 at 24 months (p < 0.0005), without reaching the pre-injury level (6.0 ± 2.2) (p < 0.0005). The IKDC objective score changed from 68.5% normal and nearly normal knees before the treatment to 90.1% at 24 months. At 24 months, age showed a correlation with the IKDC subjective score (ρ = -0.247; p < 0.0005), women had a lower score (p < 0.0005), as well as patients with patellar lesions (p = 0.002). Previous surgery correlated with lower results (p = 0.003), while better results were found in osteochondritis dissecans (OCD) compared to degenerative lesions (p = 0.001).

CONCLUSION

This cell-free biomimetic scaffold is a safe and effective treatment for cartilage knee lesions, offering positive clinical results at 2 years with a low failure rate. Better outcomes were observed in younger patients, in lesions of the femoral condyles and in OCD, while joints affected by patellar lesions, patients who underwent previous knee surgery, and women may expect lower results.

LEVEL OF EVIDENCE

Level III, cohort study.

Arthroscopic debridement followed by intra-articular injection of micro-fragmented adipose tissue in patients affected by knee osteoarthritis: Clinical results up to 48 months from a prospective clinical study

Purpose

Micro-fragmented adipose tissue is emerging as a promising option for the treatment of various diseases including knee osteoarthritis (OA), though clinical trials are often limited by short follow-up periods. Our aim was to evaluate the safety and clinical outcomes of an arthroscopic debridement followed by a single injection of micro-fragmented adipose tissue in patients affected by knee OA.

Methods

From 2016 to 2020, patients affected by knee OA were enroled. Micro-fragmented adipose tissue was obtained through the Lipogems® kit and intraarticularly injected after an arthroscopic debridement. Visual analogue scale for pain, Tegner score, Knee Injury and Osteoarthritis Outcome score subscales variations were assessed from baseline to 3, 6, 12, 24 and 48 months of follow-up.

Results

Forty-one patients were evaluated up to 6 months of follow-up, 39 patients up to 24 months of follow-up and 38 patients up to 48 months of follow-up. Three underwent knee replacement surgery during the time of the study. All the clinical scores analyzed achieved statistically significant changes up to the last follow-up.

Conclusions

A single intra-articular knee injection of micro-fragmented adipose tissue following arthroscopic debridement is able to provide significant clinical benefits in patients affected by knee OA up to 4 years of follow-up.The present clinical study was registered on clinicaltrials.gov (no. NCT06545266).

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).

Autologous matrix-induced chondrogenesis provides better outcomes in comparison to autologous minced cartilage implantation in the repair of knee chondral defects

PURPOSE

In symptomatic mid-sized focal chondral defects, autologous matrix-induced chondrogenesis (AMIC) and minced cartilage implantation (MCI) offer two versatile treatment options. This study aimed to conduct a matched-patient analysis of patient-reported outcome measures to compare these two surgical treatment methods for focal chondral defects.

METHODS

At the first centre, patients underwent a single-stage procedure in which autologous cartilage was hand-minced, implanted into the defect and fixed with fibrin glue. At the second centre, patients underwent AMIC, which was fixed in place with fibrin glue. All patients were seen 2-4 years postoperatively. Postoperative outcomes were assessed using the visual analogue scale for pain (VAS), the Lysholm score and the five domains of the knee osteoarthritis outcome score (KOOS). Patients from each surgical centre were matched by age, sex, defect size and defect localisation.

RESULTS

In total, 48 patients from two surgical centres (24 from each site) were matched for sex, age (MCI 30.3 ± 14.9 years vs. AMIC 30.8 ± 13.7 years) and defect size (MCI 2.49 ± 1.5 cm2 vs. AMIC 2.65 ± 1.1 cm2). Significantly better scores in the AMIC cohort were noted for VAS (p = 0.004), Lysholm (p = 0.043) and the KOOS subscales for pain (p = 0.016) and quality of life (p = 0.036). There was a significantly greater proportion of positive responders for Lysholm in the AMIC group (92%) compared with the MCI group (64%).

CONCLUSIONS

The AMIC procedure delivers superior patient outcomes compared with hand-minced autologous cartilage implantation. These are mid-term outcomes, with follow-up between 2 and 4 years.

LEVEL OF EVIDENCE

Level III.

Sex does not influence the long-term outcome of matrix-assisted autologous chondrocyte transplantation

PURPOSE

Regenerative techniques for articular cartilage lesions demonstrated heterogeneous clinical results. Several factors may influence the outcome, with sex being one of the most debated. This study aimed at quantifying the long-term influence of sex on the clinical outcome obtained with a regenerative procedure for knee chondral lesions.

METHODS

Matrix-assisted autologous chondrocyte transplantation (MACT) was used to treat 235 knees which were prospectively evaluated with the International Knee Documentation Committee (IKDC), EuroQol visual analogue scale, and Tegner scores at 14-year mean follow-up. A multilevel analysis was performed with the IKDC subjective scores standardised according to the age/sex category of each patient and/or the selection of a match-paired subgroup to compare homogeneous men and women patients.

RESULTS

At 14 years, men and women showed a failure rate of 10.7% and 28.8%, respectively (p < 0.0005). An overall improvement was observed in both sexes. Women had more patellar lesions and men more condylar lesions (p = 0.001), and the latter also presented a higher preinjury activity level (p < 0.0005). Men had significantly higher IKDC subjective scores at all follow-ups (at 14 years: 77.2 ± 18.9 vs. 62.8 ± 23.1; p < 0.0005). However, the analysis of homogeneous match-paired populations of men and women, with standardised IKDC subjective scores, showed no differences between men and women (at 14 years: -1.6 ± 1.7 vs. -1.9 ± 1.6).

CONCLUSION

Men and women treated with MACT for knee chondral lesions presented a significant improvement and stable long-term results. When both sexes are compared with homogeneous match-paired groups, they have similar results over time. However, women present more often unfavourable lesion patterns, which proved more challenging in terms of long-term outcome after MACT.

LEVEL OF EVIDENCE

Level II.

Theranostic Applications of Scaffolds in Current Biomedical Research

Theranostics, a remarkable combination of diagnostics and therapeutics, has given rise to tissue/organ-format theranostic scaffolds that integrate targeted therapy and real-time disease monitoring. The scaffold is a 3D structuring template for cell or tissue attachment and growth. These scaffolds offer unprecedented opportunities for personalized medicine and hold great potential for revolutionizing healthcare. Recent advancements in fabrication techniques have enabled the creation of highly intricate and precisely engineered scaffolds with controllable physical and chemical properties, enhancing their therapeutic potential for tissue engineering and regenerative medicine. This paper proposes a new categorization method for scaffolds in tissue engineering based on the relativity of scaffold design-independent parameters. Five types of scaffolds are defined at different levels, highlighting the importance of understanding and analyzing scaffold types. It possesses the ability to seamlessly integrate diagnostics and therapeutics within a single platform, enhancing the efficacy and precision of personalized medicine. Natural scaffolds derived from biomaterials and synthetic scaffolds fabricated by human intervention are discussed, with synthetic scaffolds offering advantages such as tunable mechanical properties and controlled drug delivery, while natural scaffolds provide inherent biocompatibility and bioactivity, making them ideal for promoting cellular responses. The use of synthetic scaffolds shows great promise in advancing regenerative medicine and improving patient outcomes. The transfer of new technologies and changes in society have accelerated the evolution of health monitoring into the era of personal health monitoring. Using emerging health data, cost-effective analytics, wireless sensor networks, mobile smartphones, and easy internet access, the combination of these technologies is expected to accelerate the transition to personal health monitoring outside of traditional healthcare settings. The main objective of this review article is to provide a comprehensive overview of the theranostic applications of scaffolds in current biomedical research, highlighting their dual role in therapy and diagnostics. The review aims to explore the latest advancements in scaffold design, fabrication, and functionalization, emphasizing how these innovations contribute to improved therapeutic efficacy, targeted drug delivery, and the real-time monitoring of disease progression across various medical fields.

Addressing meniscal deficiency part 2: An umbrella review of systematic reviews and meta-analyses on meniscal scaffold-based approaches

Purpose

Meniscal injuries are common in knee surgery and often require preservation techniques to prevent secondary osteoarthritis. Despite advancements in repair techniques, some patients undergo partial meniscectomy, which can lead to postmeniscectomy syndrome. To address these challenges, meniscal substitution techniques like scaffolds have been developed. However, a comprehensive synthesis of the existing evidence through an umbrella review is lacking.

Methods

A comprehensive search was conducted in the MEDLINE, Embase and Scopus databases to identify relevant systematic reviews and meta-analyses. Studies were screened based on predefined inclusion and exclusion criteria. The quality of included studies was assessed using the AMSTAR-2 tool.

Results

A total of 17 studies met the inclusion criteria and were included in the review. Most studies focused on the use of collagen-based scaffolds, with fewer studies evaluating synthetic scaffolds. The majority of studies (52.9%) were rated as having 'Critically Low' overall confidence, with only one study (5.9%) rated as 'High' confidence and most studies exhibiting methodological limitations, such as small sample sizes and lack of long-term follow-up. Despite these limitations, the majority of studies reported positive short-term outcomes, including pain relief and functional improvement, following scaffold implantation. However, some studies noted a relatively high failure rate. Radiographically, outcomes also varied, with some studies reporting morphological deterioration of the implant seen on MRI, while others noted possible chondroprotective effects.

Conclusions

Meniscal scaffold-based approaches show promise in the management of meniscal deficiency; however, the current evidence is limited by methodological shortcomings. One notable gap in the literature is the lack of clear guidelines for patient selection and surgical technique. Future research should focus on conducting well-designed randomized controlled trials with long-term follow-up to further elucidate the benefits and indications of these techniques in clinical practice. Additionally, efforts should be made to develop consensus guidelines to standardize the use of meniscal scaffolds and improve patient outcomes. Despite limited availability, synthesizing the literature on meniscal scaffold-based approaches is crucial for understanding research, guiding clinical decisions and informing future directions.

Level of Evidence

Level IV.

Autologous minced cartilage repair for chondral and osteochondral lesions of the knee joint demonstrates good postoperative outcomes and low reoperation rates at minimum five-year follow-up

PURPOSE

Minced cartilage is a one-step, autologous procedure with promising short-term results. The aim of the present study was to evaluate mid-term results in a patient cohort with chondral and osteochondral lesions in the knee joint treated with minced cartilage.

METHODS

From 2015 through 2016, a total of 34 consecutive patients were treated with a single-step, autologous minced cartilage for knee chondral and osteochondral lesions. Numeric analogue scale (NAS) for pain and knee function were obtained prior to surgery and at 12, 24 and 60 months postoperatively. Secondary outcomes, including Lysholm score, Tegner activity score, and the International Knee Documentation Committee (IKDC) score, were recorded at final follow-up. MRI examinations of patients with unplanned radiological follow-up were analysed using the MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score.

RESULTS

A total of 28 patients (44.1% females, age at surgery: 29.5 ± 11.5 years) were available at a mean follow-up of 65.5 ± 4.1 months. Mean defect size was 3.5 ± 1.8 cm2. NAS for pain decreased from a median of 7 (range: 2-10) preoperatively to 2 (0-8) postoperatively. NAS knee function improved from a median of 7 (range: 2-10) to 3 (0-7) after five years, respectively. Satisfactory Lysholm (76.5 ± 12.5), IKDC (71.6 ± 14.8) and Tegner activity (4, range 3-9) scores were reported at final follow-up. Of all patients, 21(75%) and 19 (67.9%) reached or exceeded the PASS for the IKDC- and Lysholm score at final follow-up, respectively. The average overall MOCART 2.0 scores for all postoperatively performed MRIs (n = 23) was 62.3 ± 17.4. Four (14.2%) postoperative complications were directly linked to minced cartilage, one (3.5%) of which required revision surgery.

CONCLUSION

One-step, autologous minced cartilage repair of chondral and osteochondral lesions of the knee without the necessity for subchondral bone treatment demonstrated good patient-reported outcomes, low complication rates, and graft longevity at mid-term follow-up. Minced cartilage represents a viable treatment option to more traditional cartilage repair techniques even in mid-term.

LEVEL OF EVIDENCE

Level III.

ESSKA consensus initiative: why, when and how?

The goal of a Consensus in clinical practice is to provide daily practitioners with evidence- based recommendations on data from the literature, clinical expertise and expectations of professionals and patients. In this context, a consensus aligns with the principles of evidence-based medicine in clinical practice and is consequently regarded as a scientific work of a certain level of evidence (LOE). It is expected that such a project may contribute to filling the gap observed between scientific evidence and reality of the daily practice.A Clinical Consensus is particularly needed for those topics that are of interest to daily practice but controversial due to lack of evidence, and for which expert agreement can provide valuable support in reaching conclusions.A Consensus requires a strict methodology, based on two principles: an iterative process with independence of the involved groups and pluralism (geographical and professional representation). These processes guarantee the scientific quality of the recommendations.Among the various consensus modalities, ESSKA has adopted the Formal Consensus derived from the Delphi method, and the RAND/UCLA appropriateness method. These two methods are complementary. The first one, based on questions-answers sets, is particularly suitable for questions of terminology, diagnosis, planning, strategy. The second one is based on the concept of scenarios, particularly adapted to treatment indications. These two methods can also be used within the same consensus.The aim of this article is to define what is a consensus initiative, to detail the methodology ESSKA has chosen, and to point out the key role of the dissemination.

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.

Cartilage Repair Capacity within a Single Full-Thickness Chondral Defect in a Porcine Autologous Matrix-Induced Chondrogenesis Model Is Affected by the Location within the Defect

OBJECTIVE

Large articular cartilage defects are a challenge to regenerative surgery. Biomaterial scaffolds might provide valuable support for restoration of articulating surface. The performance of a composite biomaterial scaffold was evaluated in a large porcine cartilage defect.

DESIGN

Cartilage repair capacity of a biomaterial combining recombinant human type III collagen (rhCo) and poly-(l/d)-lactide (PLA) was tested in a porcine model. A full-thickness chondral defect covering the majority of the weightbearing area was inflicted to the medial femoral condyle of the right knee. Spontaneous cartilage repair and nonoperated healthy animals served as controls. The animals were sacrificed after a 4-month follow-up. The repair tissue was evaluated with the International Cartilage Repair Society (ICRS) macroscopic score, ICRS II histological score, and with micro-computed tomography. Additionally, histopathological evaluation of lymph nodes and synovial samples were done for toxicological analyses.

RESULTS

The lateral half of the cartilage defect in the operated groups showed better filling than the medial half. The mean overall macroscopic score for the rhCo-PLA, spontaneous, and nonoperated groups were 5.96 ± 0.33, 4.63 ± 0.42, and 10.98 ± 0.35, respectively. The overall histological appearance of the specimens was predominantly hyaline cartilage in 3 of 9 samples of the rhCo-PLA group, 2 of 8 of the spontaneous group, and 9 of 9 of the nonoperated group.

CONCLUSIONS

The use of rhCo-PLA scaffold did not differ from spontaneous healing. The repair was affected by the spatial properties within the defect, as the lateral part of the defect showed better repair than the medial part, probably due to different weightbearing conditions.

Cell-Free Biomimetic Osteochondral Scaffold for the Treatment of Knee Lesions: Clinical and Imaging Results at 10-Year Follow-up

BACKGROUND

Cell-free devices have been introduced to restore osteochondral defects, avoiding the limitations of cell-based procedures. Among these, an osteochondral scaffold made of type I collagen and hydroxyapatite has been investigated with promising results up to medium-term follow-up. However, the clinical and imaging results over time still need to be documented.

PURPOSE

To evaluate the clinical outcome and tissue maturation at long-term follow-up after the implantation of the osteochondral scaffold.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 24 patients (7 women, 17 men; age, 36 ± 9.5 years) underwent surgical implantation of the osteochondral scaffold and were prospectively evaluated before surgery, at 2-, 5-, and 10-year follow-up. The mean defect size was 2.9 ± 1.4 cm². Patients were evaluated using the International Knee Documentation Committee (IKDC) subjective and objective scores, and the activity level was documented with the Tegner score. Magnetic resonance imaging (MRI) evaluation involved the use of the magnetic resonance observation of cartilage repair tissue score combined with 5 more variables focused on the bone layer.

RESULTS

A statistically significant improvement of all clinical scores was documented from the baseline to the final evaluation. The IKDC subjective score improved from the preoperative level to 2 years (41 ± 13.2 and 77.1 ± 14.6, respectively) (P < .0005), with stable results up to 10 years (77.4 ± 19.4). The IKDC objective score changed from 52% of normal and nearly normal knees before the treatment to 84% at 10 years (P < .0005). Tegner sports activity at the final evaluation (3.8 ± 1.7) was higher compared with the preoperative level (1.6 ± 1.1; P < .05), but it remained significantly lower compared with the preinjury level (5.5 ± 2.6; P < .05). Treatment failed in 1 patient. Persisting graft alterations were observed on MRI scans, although without correlating with the clinical outcome.

CONCLUSION

The regenerative potential of this scaffold is limited, as demonstrated by the signal alterations persisting over time on MRI scans. On the other hand, the clinical improvement was significant and stable over time both in terms of subjective and objective outcomes, including activity level, with overall good results.

Bone marrow aspirate concentrate and scaffold for osteochondral lesions of the talus in ankle osteoarthritis: satisfactory clinical outcome at 10 years

PURPOSE

To evaluate at long-term follow-up patients undergoing a one-step procedure of debridement and BMAC seeded in situ onto a scaffold for the treatment of osteochondral lesions of the talus (OLT) in ankles affected by osteoarthritis (OA), documenting the duration of the clinical benefit and its efficacy in postponing end-stage procedures.

METHODS

This series included 56 consecutive patients. Patients were evaluated preoperatively and up to a mean of 10 years of follow-up with the AOFAS score and the AOS scale, including pain and disability subscales. Furthermore, patients were asked to rate the satisfaction and failures were documented as well.

RESULTS

The AOFAS score improved from 52.3 ± 14.3 to 73.5 ± 23.1 at 10 years (p  < 0.0005); the AOS pain and disability subscales decreased from 70.9 ± 14.1 to 37.2 ± 32.7 and from 69.0 ± 14.8 to 34.2 ± 29.3, respectively (both p < 0.0005). The overall rate of satisfaction was 61.8 ± 41.2 and 68.6% of patients would undergo again the surgical procedure. A total of 17 failures was documented, for a failure rate of 33.3%. Older patients and those with more complex cases requiring previous or combined surgeries had lower outcomes, as well as those affected by grade 3 OA, who experienced a high failure rate of 71.4%.

CONCLUSIONS

This one-step technique for the treatment of OLT in OA ankles showed to be safe and to provide a satisfactory outcome, even if patients with end stage OA presented a high revision rate at 10 years. Moreover, this procedure was effective over time, with overall good results maintained up to a long-term follow-up. However, older age, more complex cases requiring previous or combined surgeries, and advanced OA led to an overall worst outcome and a significantly higher failure rate.

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.

Osteoconductive Properties of a Volume-Stable Collagen Matrix in Rat Calvaria Defects: A Pilot Study

Volume-stable collagen matrices (VSCM) are conductive for the connective tissue upon soft tissue augmentation. Considering that collagen has osteoconductive properties, we have investigated the possibility that the VSCM also consolidates with the newly formed bone. To this end, we covered nine rat calvaria circular defects with a VSCM. After four weeks, histology, histomorphometry, quantitative backscattered electron imaging, and microcomputed tomography were performed. We report that the overall pattern of mineralization inside the VSCM was heterogeneous. Histology revealed, apart from the characteristic woven bone formation, areas of round-shaped hypertrophic chondrocyte-like cells surrounded by a mineralized extracellular matrix. Quantitative backscattered electron imaging confirmed the heterogenous mineralization occurring within the VSCM. Histomorphometry found new bone to be 0.7 mm² (0.01 min; 2.4 max), similar to the chondrogenic mineralized extracellular matrix with 0.7 mm² (0.0 min; 4.2 max). Microcomputed tomography showed the overall mineralized tissue in the defect to be 1.6 mm³ (min 0.0; max 13.3). These findings suggest that in a rat cranial defect, VSCM has a limited and heterogeneous capacity to support intramembranous bone formation but may allow the formation of bone via the endochondral route.

Treatment of big osteochondral defects in the lateral femoral condyle in young patients with autologous graft and collagen mesh

The treatment of massive osteochondral defects in young patients constitutes a challenge for the orthopaedic surgeon. On the one hand, facing the biological filling and on the other, guaranteeing the function in the short and long term. Defects in the lateral femoral condyle are extremely rare. We studied 7 cases of massive bone defects in the lateral condyle, 2 of them bilateral, with a median surface area of 6.8cm² (IQR: 4.9-7.0cm²) and a median depth of 2.8cm (IQR; 2.2-3.2cm). The patients were between 17 and 21 years old, without any previous traumatic background and were treated with autologous iliac crest graft and collagen mesh (Cartmaix-Matricel). Pre and postoperative clinical (Lysholm, Tegner, KOOS) and radiological tests (3D Mocart) have been carried out. Best improvement have seen in clinical parameters have been normalized in all patients, with a return to sports activities. Likewise, the radiological defect has been recovered in all of them, subtotally but more than 50%. Massive osteochondral defects in the lateral condyle could be treated by filling with autologous crest bone and a collagen mesh, with good clinical and radiological results, constituting a rational option in the therapeutic approach.

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

BACKGROUND

Osteoarthritis (OA) is considered a contraindication to most cartilage repair techniques. Several regenerative approaches have been attempted with the aim of delaying or preventing joint replacement, with controversial results. Currently, there is a paucity of data on the use of single-step techniques, such as cell-free biomimetic scaffolds, for the treatment of joint surface lesions (JSLs) in OA knees.

PURPOSE

To present the 2-year follow-up clinical and radiological outcomes after implantation of a novel, cell-free aragonite-based scaffold for the treatment of JSLs in patients with mild to moderate knee OA in a multicenter prospective study.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 86 patients, 60 male and 26 female, with a mean age of 37.4 ± 10.0 years, mild to moderate knee OA, and a mean defect size of 3.0 ± 1.7 cm², were recruited at 8 medical centers according to the following criteria: radiographic mild to moderate knee OA (Kellgren-Lawrence grade 2 or 3); up to 3 treatable chondral/osteochondral defects (International Cartilage Repair Society grades 3 and 4) on the femoral condyles or trochlea; a total defect size ≤7 cm²; and no concurrent knee instability, severe axial malalignment, or systemic arthropathy. All patients were evaluated at baseline and at 6, 12, 18, and 24 months after implantation using the Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) subjective score. Additionally, magnetic resonance imaging (MRI) was performed to assess the amount of cartilage defect filling at the repaired site.

RESULTS

Significant improvement on all KOOS subscales was recorded from baseline (Pain: 49.6 ± 13.1; Activities of Daily Living [ADL]: 56.1 ± 18.4; Sport: 22.8 ± 18.8; Quality of Life [QoL]: 23.5 ± 16.5; Symptoms: 55.4 ± 19.9) to the 24 months' follow-up (Pain: 79.5 ± 21.1 [P < .001]; ADL: 84.1 ± 21.4 [P < .001]; Sport: 60.8 ± 31.9 [P < .001]; QoL: 54.9 ± 30.4 [P < .001]; Symptoms: 77.7 ± 21.2 [P < .001]). The IKDC subjective score showed a similar trend and improved from 37.8 ± 14.7 at baseline to 65.8 ± 23.5 at 24 months (P < .001). MRI showed a significant increase in defect filling over time: up to 78.7% ± 25.3% of surface coverage after 24 months. Treatment failure requiring revision surgery occurred in 8 patients (9.3%).

CONCLUSION

The use of an aragonite-based osteochondral scaffold in patients with JSLs and mild to moderate knee OA provided significant clinical improvement at the 24-month follow-up, as reported by the patients. These findings were associated with good cartilage defect filling, as observed on MRI.

Autologous chondrocytes versus filtered bone marrow mesenchymal stem/stromal cells for knee cartilage repair-a prospective study

PURPOSE

To document clinical, radiologic, and cellular data of a prospective patient series treated by a tri-layer collagen-hydroxyapatite biomimetic osteochondral scaffold (CHAS) intra-operatively seeded with cultivated autologous chondrocytes (AC) or with filtered bone marrow stem/stromal cells (fBMSC) to address chronic osteochondral knee lesions.

METHODS

Thirty-six consecutive patients (15 to 59 years) with chronic osteochondral lesions (1.8-10 cm²) in the condylar or patellofemoral knee surfaces were enrolled. Lesions were covered with CHAS fixed with a fibrin glue. The superficial layer of CHAS was intra-operatively injected with active cells: in initial five patients, ACs were put directly onto dry CHAS (dry-AC); next, eight AC patients had CHAS moistened with cell culture media (media-AC), while the tourniquet was released allowing blood soaking of CHAS in the rest (14 blood-AC, 9 blood-fBMSC). Seventeen (50%) patients required different concomitant procedures. All patients were followed for serious adverse events (SAE) or graft failures; clinical, radiographic, and MRI evaluation was conducted. Cellular data on the injected cells were assessed.

RESULTS

At a follow-up of 39 months (16-81), 17 patients required an additional surgical intervention: seven graft-related SAE (early post-operative synovitis and/or arthrofibrosis) were registered (3 dry-AC, 3 media-AC, 1 blood-fBMSC). There were two graft failures (1 dry-AC, 1 blood-fBMSC) for secondary reasons. All clinical scores significantly improved from pre- to post-operative values: IKCD subjective 44 to 65; IKDC examination (9/17/5/5) to (20/10/5/1); KOOS (P61/S59/ADL67/Sp32/QoL31) to (P79/S75/ADL84/Sp55/QoL51); Tegner activity scale 3.3 to 4.4. There was evidence of radiographic osteoarthritis progression-Kellgren-Lawrence 1.0 to 1.5. MOCART scores at the final follow-up averaged 71 (10 to 95). Graft-type analysis demonstrated an increased rate of graft-related SAE in dry-AC and media-AC, but their final outcomes were equivalent. Cellular data of AC at the implantation were as follows: cells in suspension 9.2 × 10⁶, viability 95%. In blood-fBMSC group, a cell suspension with 87% viability was injected, which contained 1156 CFU-Fs.

CONCLUSION

CHAS with intra-operative seeding of active cells, either AC or fBMSC, led to an overall successful outcome for the treatment of chronic osteochondral lesions in the knee. Blood soaking of CHAS in situ before cell seeding significantly decreased early post-operative adverse events, such as synovitis and arthrofibrosis.