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Purpose: To characterize and compare the quality of regenerative cartilage tissue (ReCT) after conventional minced cartilage (CMC) and arthroscopic minced cartilage (AMC), in terms of cell viability, gene expression, and matrix synthesis and to investigate the influence of different shaver types., Methods: Chondral tissue was harvested from the knees of 8 porcine donors. Porcine specimens were euthanized one day before harvest. AMC was created with 2 shaver blades in 2 operating modes (oscillating vs forward) and compared with a scalpel-fragmented CMC control. Before histologic analysis, 50% of the tissue was digested to prevent dedifferentiation of chondrocytes to fibroblasts. Cells were cultured and analyzed for cell viability, gene expression of cartilage-specific markers (aggrecan [ACAN], collagen type II, alpha1 [COL2A1], collagen type I, alpha1 [COL1A1], fibronectin-1 [FN1]), and matrix synthesis (Alcian-blue)., Results: AMC tissue contained fewer viable chondrocytes (41%-54% vs 91%; P = .001-.048) compared with CMC. After culture, CMC showed greater expressions of ACAN (27 virtual copy numbers [VCN]/housekeeping gene) and COL2A1 (30 VCN) compared with AMC (ACAN 2-9 VCN, COL2A1 2-7 VCN, P = .001-.039). AMC presented greater expressions of COL1A1 (9-21 VCN) and FN1 (12-17 VCN) than CMC (1 and 6 VCN, P = .001-.050). The signal intensity of the cartilage matrix formed by CMC (86/mm 2 ) was greater than by AMC (7-10 mm 2 , P = .001-.032)., Conclusions: CMC contained high numbers of viable chondrocytes, resulting in high-quality, hyaline-like ReCT. In contrast, AMC showed impaired chondrocyte quantity and viability, showing greater expressions of fibroblast markers and a decreased formation of mature cartilage matrix in porcine samples. The high chondrogenic potential of CMC to form hyaline-like ReCT was not confirmed for AMC., Clinical Relevance: On the basis of our findings, arthroscopic harvest of minced cartilage leads to reduced chondrocyte viability and ReCT quality. Accordingly, CMC and AMC cannot be regarded as synonymous techniques, as arthroscopic techniques seem to be less efficacious., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: Cartilage defects in the knee can be caused by injury, various types of arthritis, or degeneration. As a long-term consequence of cartilage defects, osteoarthritis can develop over time, often leading to the need for a total knee replacement (TKR). The treatment alternatives of chondral defects include, among others, microfracture, and matrix-associated autologous chondrocyte implantation (M-ACI). The purpose of this study was to determine cost-effectiveness of M-ACI in Germany with available mid- and long-term outcome data, with special focus on the avoidance of TKR., Materials and Methods: We developed a discrete-event simulation (DES) that follows up individuals with cartilage defects of the knee over their lifetimes. The DES was conducted with a status-quo scenario in which M-ACI is available and a comparison scenario with no M-ACI available. The model included 10,000 patients with articular cartilage defects. We assumed Weibull distributions for short- and long-term effects for implant failures. Model outcomes were costs, number of TKRs, and quality-adjusted life years (QALYs). All analyses were performed from the perspective of the German statutory health insurance., Results: The majority of patients was under 45 years old, with defect sizes between 2 and 7 cm 2 (mean: 4.5 cm 2 ); average modeled lifetime was 48 years. In the scenario without M-ACI, 26.4% of patients required a TKR over their lifetime. In the M-ACI scenario, this was the case in only 5.5% of cases. Thus, in the modeled cohort of 10,000 patients, 2700 TKRs, including revisions, could be avoided. Patients treated with M-ACI experienced improved quality of life (22.53 vs. 21.21 QALYs) at higher treatment-related costs (18,589 vs. 14,134 € /patient) compared to those treated without M-ACI, yielding an incremental cost-effectiveness ratio (ICER) of 3376 € /QALY., Conclusion: M-ACI is projected to be a highly cost-effective treatment for chondral defects of the knee in the German healthcare setting., (© 2021. The Author(s).)

Subjective patient satisfaction is the most relevant parameter for assessing the success of treatment after orthopaedic surgery. The aim of the present study was to correlate patient-reported outcome parameters (i.e., absolute KOOS, KOOS increase) and revision-free survival with patient's satisfaction. Furthermore, the study aimed on the identification of pre-operative factors that are associated with patient's satisfaction after the surgery.For the present study, 6305 consecutive patients from the German Cartilage Registry (KnorpelRegister DGOU) were analyzed. Patient characteristics and outcome were correlated with patients' satisfaction after a follow-up of three years by Spearman correlation. P values < 0.05 were considered statistically significant.Mean age was 37 ± 12.5 years, 59.7% patients were male, and 40.3% female. Most patients (46.7%) were treated with an autologous chondrocyte implantation (ACI). The strongest correlation of subjective satisfaction and the subscore quality of life (r = 0.682; p < 0.001) was found, whereas the post-operative increase in KOOS from the pre-operative value showed only a moderate correlation (r = 0.520; p < 0.001). There was also a significant correlation with the absolute KOOS value (r = 0.678; p < 0.001), the subscores pain (r = 0.652; p < 0.001), quality of life (r = 0.682; p < 0.001), and sports (r = 0.633; p < 0.001), whereas symptoms (r = 0.504, p < 0.001) and activities of daily life (r = 0.601; p < 0.001) showed a weaker correlation. Pain also correlated highly significant with the patient satisfaction 24 months after surgery (r =  - 0.651, p < 0.001). The correlation between satisfaction after the 2nd and 3rd year (r = 0.727; p < 0.001) is stronger than correlation after six months and three years (r = 0.422, p < 0.001). All pre-operative parameters show a very weak correlation (r < 0.1).The use of standardized measuring instruments (KOOS and Pain) is a relevant outcome parameter in science and clinical practice, whereas absolute values represent satisfaction better than the individual increase. The subscores "pain," "quality of life," and "sports" represent satisfaction better than the subscores "symptoms" and "activity of daily life." Early satisfaction has only a moderate predictive value for satisfaction after 3 years, which is of great practical relevance in particular for the assessment of potential treatment failures. It is remarkable to note that a revision surgery is only very mildly associated with increased dissatisfaction. Pre-operative factors are not reliable prediction factors for post-operative patient satisfaction., (© 2021. The Author(s).)

Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Surgical principles for treatment of full-thickness cartilage defects of the knee include bone marrow stimulation techniques (i.e. arthroscopic microfracturing) and transplantation techniques (i.e. autologous chondrocyte implantation and osteochondral transplantation). On the basis of increasing scientific evidence, indications for these established therapeutical concepts have been specified and clear recommendations for practical use have been given. Within recent years, matrix-augmented bone marrow stimulation has been established as a new treatment concept for chondral lesions. To date, scientific evidence is limited and specific indications are still unclear. The present paper gives an overview of available products as well as preclinical and clinical scientific evidence. On the basis of the present evidence and an expert consensus from the "Working Group on Tissue Regeneration" of the German Orthopaedic and Trauma Society (DGOU), indications are specified and recommendations for the use of matrix-augmented bone marrow stimulation are given. In principle, it can be stated that the various products offered in this field differ considerably in terms of the number and quality of related studies (evidence level). Against the background of the current data situation, their application is currently seen in the border area between cell transplantation and bone marrow stimulation techniques, but also as an improvement on traditional bone marrow stimulation within the indication range of microfracturing. The recommendations of the Working Group have preliminary character and require re-evaluation after improvement of the study situation., Competing Interests: Die Autoren geben an, dass kein Interessenkonflikt besteht., (Georg Thieme Verlag KG Stuttgart · New York.)