Partial Meniscus Allograft Transplantation Preserving the Recipient’s Anterior Root: A Comparative Study in a Rabbit Model

Partial Meniscus Allograft Transplantation Preserving the Recipient’s Anterior Root: A Comparative Study in a Rabbit Model | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Partial Meniscus Allograft Transplantation Preserving the Recipient’s Anterior Root: A Comparative Study in a Rabbit Model Hao Tan, Hao Qin, Yu Chen, Enrun Wang, Aiguo Zhou, Chengjie Lian, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6881658/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Dec, 2025 Read the published version in European Journal of Medical Research → Version 1 posted 9 You are reading this latest preprint version Abstract This study compared partial (PMAT) and total meniscus allograft transplantation (TMAT) in rabbits, assessing their impact on meniscus function preservation and degeneration delay. In 18 rabbits with induced meniscus defects, PMAT better preserved meniscus morphology, collagen fibers, and showed less inflammation and better cartilage protection than TMAT. Histological staining and RNA sequencing revealed PMAT maintained collagen distribution and certain gene expression patterns closer to normal tissues. These findings suggest PMAT may offer advantages in reducing inflammation, delaying degeneration, and protecting cartilage, providing a potential new clinical approach for meniscus injuries and a basis for further research on meniscus repair mechanisms. Meniscus allograft transplantation Anterior root Rabbit model RNA sequencing Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 1. Introduction The meniscus is an essential part of the knee joint, responsible for stress transmission, shock absorption, joint stability, proprioception, and lubrication of the knee [1-3] . The articular surfaces of the femoral condyle and tibial plateau can achieve optimal joint congruence through the characteristic concave-convex structure of the meniscus, increasing the joint contact area and enhancing knee stability [4] . However, the meniscus is highly susceptible to injury, with an incidence rate of up to 14% [5] . In cases of meniscus injury, arthroscopic suturing repair is preferred. However, for severely damaged menisci or those with poor blood supply, meniscectomy and reshaping are the only viable options [6,7] . Research indicates that excision of the medial and lateral menisci results in a 100%-300% increase in the contact stress in the respective knee compartments, thereby accelerating the progression of knee osteoarthritis [8] . Meniscus transplantation is a clinically well-accepted choice for young patients with active lifestyles after total meniscectomy, or for those who continue to experience knee symptoms after total meniscectomy [9] . Current meniscus transplantation techniques include allograft meniscus transplantation and artificial meniscus transplantation. Artificial meniscus materials include synthetic implants and tissue-engineered menisci. Synthetic implants, including collagen meniscus implants (CMI) and polyurethane polymer implants (Actifit), can only be used for the repair of partial meniscal defects [10] . Replacement meniscus implants, such as NUsurface, are used for meniscus reconstruction following total meniscectomy, but their clinical application is still limited, and the postoperative efficacy is not well established [11] . Tissue-engineered menisci are expected to more effectively reconstruct the meniscus's heterogeneous structure and yield better long-term prognoses, although they are currently in the preclinical trial stage [12,13] . Clinical application of allograft meniscus transplantation has become more widespread, yielding favorable cartilage protection outcomes post-surgery, and resulting in high patient satisfaction [14-19] . Notably, many studies have indicated that the incidence of meniscus injuries differs across regions, with the occurrence of posterior root injuries being higher than that of the anterior root in both acute and chronic knee injuries [20-22] . Additionally, we also observed that most patients have meniscus tears in the posterior root, with the remaining anterior root maintaining a relatively good quality. Thus, in meniscus transplantation, there appears to be an opportunity to retain the complete anterior root of the recipient's meniscus. Furthermore, research has shown that after meniscus transplantation, atrophy of the graft's anterior root is one of the most common signs of graft degeneration [23-25] . In the postoperative follow-up of patients undergoing allograft meniscus transplantation in our department, we observed that 23 out of 75 patients exhibited varying degrees of anterior root atrophy at different postoperative time points. Although the cause and mechanism of anterior root atrophy remain unclear, preserving the recipient’s original meniscus anterior root seems promising in slowing the rate of anterior root atrophy post-transplantation, potentially extending the graft’s lifespan and delaying the progression of osteoarthritis. At present, there are some pre-clinical studies on the repair of meniscus fragments and the transplantation of only the meniscus posterior root [26,27] . However, no studies have explored the postoperative efficacy and the morphological changes of the meniscus following partial meniscus allograft transplantation with preservation of the recipient’s anterior root. This study aims to preserve the recipient's anterior root during allograft meniscus transplantation and perform partial meniscus transplantation. A rabbit model was used in this study to evaluate whether the partial meniscus allograft transplantation group (PMAT), with preservation of the anterior root, will more effectively preserve the physiological function of the meniscus and slow the degeneration of the meniscus allograft and articular cartilage when compared to the total meniscus allograft transplantation group (TMAT). 2. Materials and methods 2.1 Research approval All animal experimentation procedures in this study were conducted in accordance with the 8th edition of the Guide for the Care and Use of Laboratory Animals published by the National Research Council and received approval from the Institutional Animal Care and Use Committee of Chongqing Medical University (Approval No. IACUC-CQMU-2023-0038). 2.2 Animal model 18 female New Zealand rabbits (3.0–3.5 kg) were procured from the animal laboratory at Chongqing Medical University and randomly assigned to different groups. In all rabbits, a 3-cm medial parapatellar incision was made to expose the medial knee compartment. The medial collateral ligament and joint capsule were incised, and the medial meniscus was isolated by transecting its roots at the tibial plateau. The excised menisci were cleaned with sterile saline. In the DMM group, menisci were stored at -80 °C in vacuum bags without cryoprotectant. In the TMAT group, menisci were trimmed, transplanted into another recipient within 2 hours, and sutured to the joint capsule. In the PMAT group, the meniscus was harvested in a manner similar to the previous method. At this point, the junction between the anterior horn and body of the right medial meniscus, as well as the posterior horn attachment to the tibial plateau, were transected to separate the medial meniscus. Following the above steps, the medial collateral ligament was sutured using 2-0 non-absorbable sutures, and the joint capsule and skin were subsequently closed. The wound was covered with sterile gauze and bandaged. Within 3 days post-surgery, antibiotics were administered intramuscularly, wound dressings were changed to prevent infection. No plaster cast was applied, and the recipient was allowed to move freely in a standard housing cage. Euthanasia was performed at 6 weeks and 12 weeks post-surgery. Gross images of the surgical side knee joint were taken, and the meniscus and articular osteochondral tissue post-transplantation were collected for subsequent analysis. 2.3 Hematoxylin and eosin (H&E) staining The obtained meniscus and osteochondral tissue specimens were fixed in 4% neutral formalin for 48 hours and decalcified using a 10% EDTA solution for 1 month. After washing overnight with distilled water, the decalcified specimens were dehydrated using ethanol of varying concentrations, cleared with xylene, and then embedded in paraffin. Using a paraffin microtome, 4 μm thick sections were made along the coronal plane of the femoral condyle and tibial plateau. The sections were stained with hematoxylin-eosin and observed under a microscope (Olympus). 2.4 Safranin O staining The sections were deparaffinized in xylene and rehydrated using a gradient of ethanol. The sections were stained with Safranin O solution for 5 minutes, then differentiated in acidic ethanol for 15 seconds, and washed with running water. The sections were stained with Picrosirius Red solution for 3 minutes, then quickly dehydrated with anhydrous ethanol three times. After mounting with neutral resin, the sections were examined under an optical microscope. 2.5 Picrosirius Red (PR) staining Paraffin sections are routinely deparaffinized with xylene and hydrated through a gradient of ethanol. Sections were stained following the instructions of the Picrosirius Red reagent (Solarbio, Beijing, China). After staining, the sections were dehydrated and mounted with neutral resin. They were then observed under a polarized light microscope, and the integrated optical density (IOD) was measured using ImageJ. 2.6 Immunohistochemistry (IHC) staining The sections were deparaffinized with xylene and hydrated using a gradient of ethanol. The slides were incubated with hydrogen peroxide to inhibit endogenous peroxidase activity, followed by blocking nonspecific binding sites with goat serum. Next, an appropriate volume of the primary antibody was added and incubated overnight at 4°C. On the second day, the samples were incubated with secondary and tertiary antibodies at room temperature for 30 minutes, then stained with diaminobenzidine and counterstained with hematoxylin. Immunohistochemical images were subsequently taken under a light microscope. 2.7 Scanning electron microscope (SEM) examination The meniscus allografts obtained at 12 weeks from the control group (The entire meniscus obtained from the M group), PMAT group, and TMAT group were cut into sizes of ≤ 1 cm² in area and ≤ 5 mm in thickness. The trimmed grafts were rinsed with physiological saline, placed in fixative, and stored at 4°C before undergoing scanning electron microscopy. The ultrastructure was observed using a Hitachi S-3000N scanning electron microscope (Hitachi High-Technologies Corporation, Japan). 2.8 RNA extraction and transcriptome sequencing Total RNA was extracted from the New Zealand rabbit meniscus tissue using Trizol reagent (Takara, Japan). After assessing RNA purity and integrity, sequencing libraries were prepared using the Illumina® RNA Library Preparation Kit (NEB, USA) and sequenced on the Illumina platform. Gene expression levels were estimated using StringTie (v2.1.6), and differential expression analysis was performed using the DESeq2 R package (v1.32.0), with a P -value threshold of < 0.05 for selecting differentially expressed genes. 2.9 Functional enrichment analysis Enrichment analysis (GSEA) for Gene Ontology (GO), and Disease Ontology (DO) was performed using the clusterProfiler (4.0.0) R package, with a P -value threshold of < 0.05 for statistically significant results. 2.10 Evaluation of implants and joint cartilages Following euthanasia of the recipient animals, the knee joint was opened, and photographs of the joint capsule cavity were taken. The graft healing (0 = healed, 1 = not healed), shrinkage (0 = none, 1 = anterior or posterior horn, 2 = both anterior and posterior horns, 3 = entire graft), extrusion (0 = none, 1 = anterior or posterior horn, 2 = entire graft), and osteophyte formation (0 = none, 1 = femoral condyle or tibial plateau, 2 = both femoral condyle and tibial plateau) were evaluated visually. Histological quantitative assessment of graft morphology and healing was performed using the Rodeo and Ishida scoring systems [28,29] . Articular cartilage damage was evaluated histologically using the Mankin scoring system [30] . All specimens were assessed in a double-blind manner by two researchers, with the final results being the average value. 2.11 Statistical analysis All statistics are presented as mean ± SD. Data analysis was performed using nonparametric tests. All data analyses were performed using SPSS statistical software (version 25.0, ibm-spss, Armonk, NY). A P value less than 0.05 was considered statistically significant. 3. Results 3.1 Gross evaluation of implants All the rabbits that underwent the surgical procedure experienced smooth recoveries, with no significant alterations in weight, infections, or other complications. At 6 and 12 weeks postoperatively, an overall evaluation was conducted on the implants of TMAT and PMAT groups. From the gross view, the TMAT group's implants received significantly lower scores compared to the PMAT group in terms of implant positioning, surface characteristics, tissue integration, and synovial response (Table 1). The majority of these implants had integrated well with the normal attachment sites, showing no evidence of fractures or gaps. Within the PMAT group, all the six implants examined displayed a healthy, normal appearance, whether at 6 weeks or 12 weeks postoperatively. And there was no noticeable synovial hyperplasia or tears in the implants (Figure 1A). In the TMAT group, two of the implants were observed to be slightly protruding, with evidence of synovial proliferation. Additionally, the implants in the TMAT group were notably softer, and their surfaces exhibited a rough texture. Besides, after 12 weeks of surgery, there was obvious dissolution in the anterior foot of the meniscus in the TMAT group. 3.2 Histological evaluation of implants The composition and spatial distribution of collagen in regenerated meniscus was analysed by HE and Safranin O-Fast green staining. As shown in Figure 1B, at both 6 weeks and 12 weeks post-surgery, the anterior root of meniscus in the PMAT group exhibited similar shapes and collagen fiber distribution to those of normal tissues. While in the TMAT group, the number of fibrochondrocytes in the local collagen fibres of the donor meniscus decreased. Especially in the 12-week group, the collagen fibers in the meniscus showed significant looseness and deformation. The transplanted meniscus has a similar distribution of collagen cells and chondrocytes as the normal meniscus, but low cell density areas were still observed in all implants within the TMAT group. The PMAT group outperformed the TMAT group on the Ishida scoring system (Figure 2A). but no significant difference was observed between the two groups when assessed using the Rodeo scoring system (Figure 2B). As shown in Figure 3A, quantitative analysis of collagen content was performed using polarized Sirius red light staining, and red fibres represent COL-1, while green fibres represent COL-3. Compared with PMAT group and Control group, both COL-1 and COL-3 showed a significant reduction in TMAT group, which was also validated on the IOD (integrated optical density) of each group (Table 2). Immunohistochemical staining showed that the PMAT group and the Control group exhibited similar levels of collagen fibers and matrix metalloproteinases (figure 3B). In contrast, the TMAT group showed significantly reduced expression of COL-1 and COL-2, while displaying elevated levels of MMP-9 and MMP-13. In SEM image (figure 4), the Control and PMAT groups showed intact meniscus tissues with tightly - arranged fibers and uniform pores under low magnification, and clear fiber structures with even diameters and smooth surfaces under high magnification. But the TMAT group presented damaged fiber structures, loosely-arranged fibers, enlarged and uneven pores under low magnification, and smaller fiber diameters, rough surfaces, and weakened fiber connections under high magnification, indicating its poor performance. 3.3 Evaluation of cartilage In the gross look of articular cartilage (Figure 5), the PMAT group exhibited no significant articular cartilage tears or degeneration. In contrast, the TMAT group showed loss of cartilage surface luster, appearing rough with varying degrees of damage. The DMM group showed the most severe impairment, with visible exposure of the subchondral bone and cracks on the cartilage surface. cracks appeared on the cartilage surface of the TMAT group, accompanied by an uneven distribution of chondrocytes. Safranin O staining showed a moderate reduction, with irregular changes on the surface of the femoral condyle and tibial plateau. In the PMAT group, the chondral layers were distinct, the tidemark was intact, and cellularity within each stratum was normal. Nuclei showed deep staining, and Safranin O staining was pronounced, closely resembling the Control group. Histological evaluation and Mankin scoring indicated the most severe cartilage damage in the DMM group, followed by the TMAT group (Figure 6). 3.4 Analysis of meniscus transcriptome by RNA sequencing RNA sequencing was conducted on meniscal samples at 6 and 12 weeks following total meniscus transplantation, as well as in a control group, to assess alterations in gene expression. A total of 130 genes showed significant expression changes in all three groups compared to each other, suggesting their potential utility as critical targets in mechanistic studies of meniscal regeneration (Figure S1). The analysis of the Pearson similarity heatmap demonstrates a significant correlation among the three groups of samples. This indicates that the variables within these groups are closely related, suggesting potential shared underlying patterns or mechanisms (Figure 7A, 7B). The heatmaps in Figures S2 and S3 show the upregulation and downregulation levels of the differentially expressed genes selected. Comparing with the Control Group, genes such as KRT78, COL1A1, MMP13 and FNDC1 were significantly upregulated after 6 weeks of transplantation. Conversely, genes like KLB, UVRAG, and CLEC3A exhibited marked downregulation (Figure 7C). While after 12 weeks of transplantation, ATP6V0DZ, GPNMB, and DKK3 were significantly upregulated, and significant downregulation of LEPR, CXCL5, and IGFBP5 was observed (Figure 7D). Cluster analysis of the differentially expressed genes (DEGs) demonstrated excellent intra-group sample consistency and significant inter-group differences. Gene Ontology (GO) analysis revealed dynamic functional changes over time. At 6 weeks post-transplantation, downregulated pathways included membrane and integral component of membrane, while upregulated pathways included immune response and microtubule-based movement (Figure 7E, 7F). At 12 weeks post-transplantation, downregulated pathways shifted to protein binding and plasma membrane, while extracellular space and cell surface remained upregulated (Figure 7G, 7H). These results highlight the temporal dynamics of gene expression following transplantation. For alternative splicing events with significant differences in expression, the project visualizes them using rmats2sashimiplot. Compared with the normal meniscus, the inclusion levels of SFXN4 and CPLANE1 were significantly reduced after 6 weeks of transplantation (Figure 8A, 8B), and those of EVI5 and PTGR1 decreased after 12 weeks of transplantation (Figure 8C, 8D). This is of significant importance for identifying targets related to meniscus healing, degeneration, and metabolism in subsequent research. 4. Discussion In this study, our research showed that the PMAT group had less wear and degeneration of the anterior root post-surgery compared to the TMAT group, with better preservation of collagen fiber content and structure. Additionally, the PMAT group showed less local inflammatory response, and the meniscus allograft demonstrated superior cartilage protection. It further highlighted the effect of the sequential expression of genes like SFXN4 and CPLANE1 on meniscus tissue repair and regeneration after transplantation. Our study provides reliable preclinical evidence for the improvement of future meniscus transplantation surgical techniques. Our study will offer additional theoretical support and alternative approaches for the advancement of clinical meniscus transplantation techniques. Our study demonstrated that the PMAT group exhibited superior outcomes in meniscus morphology and cartilage protection compared to the TMAT group. This aligns with prior findings, such as Strauss et al.'s study showing partial healing of meniscus fragment grafts in sheep after 90 days [31] , and Haber et al.'s work restoring knee joint biomechanics in cadaver specimens [32] . Additionally, Fan et al. observed reduced inflammation, improved graft healing, and superior biomechanical performance in Beagle dogs following partial meniscus transplantation, with specific genes like KNTC1 and RAD51AP1 implicated in tissue repair [33] . These results may stem from three key factors: (1) PMAT preserved native meniscus tissue in the anterior root, reducing inflammation and immune rejection, as evidenced by lower post-surgical MMP-9 and MMP-13 levels; (2) retention of the native anterior root and roots ensured proper graft positioning, restoring biomechanical effects and enhancing cartilage protection; and (3) preserved soft tissue connections maintained blood supply to the anterior root, delaying degeneration and optimizing meniscus morphology. These findings underscore the clinical potential of PMAT in improving long-term outcomes and reducing complications. Current understanding of molecular mechanisms governing meniscus regeneration remains limited, necessitating comprehensive exploration of regulatory biomarkers to enhance transplantation outcomes [34,35] . Integrated transcriptomic and proteomic analyses reveal distinct expression patterns of key molecules in post-surgical repair processes [36,37] . Notably, MMP13 exhibits significant upregulation across immunohistochemical and genomic assessments, suggesting its pathological role in extracellular matrix (ECM) degradation through excessive cleavage of collagen fibers, thereby impairing cellular adhesion, proliferation, and differentiation in the anterior root region. Concurrently, SFXN4 and CPLANE1 demonstrate marked downregulation at 6-week post-operation, potentially reflecting suppressed collagenocyte metabolic activity and proliferative capacity under persistent inflammatory conditions characterized by elevated MMP9/MMP13 expression. Longitudinal analysis identifies temporal regulatory patterns, with EVI5 downregulation at 12 weeks indicating cell cycle dysregulation through impaired APC/C-Emi1 complex stabilization, while diminished PTGR1 expression suggests potential dual impacts on eicosanoid-mediated inflammation modulation and compromised matrix remodeling [38,39] . These findings collectively highlight dynamic molecular interplay between matrix metalloproteinase activity, cellular metabolic regulation, and inflammatory signaling during meniscus repair, though precise transcriptional networks and temporal regulatory mechanisms warrant further mechanistic investigation. The technique of meniscus transplantation has become well-established. Nevertheless, there is a paucity of literature examining how the tissue morphology of the transplanted anterior root alters after allogeneic meniscus transplantation [40,41] . Additionally, there is an absence of research assessing its influence on clinical outcomes or investigating potential risk factors. In our study, we utilized rabbit models and applied a variety of MAT techniques to repair meniscus defects. Our study confirmed that the repair efficacy of PMAT technology surpasses that of TMAT technology, which empowers us to proactively delve into the viability of PMAT, thereby delivering enhanced therapeutic outcomes to a broader spectrum of patients, particularly those grappling with meniscus injuries in the anterior root region. Further clinical trials are needed to explore the efficacy of PMAT. Furthermore, we identified the potential gene targets, activated signaling pathways, and cellular functions underlying this advantage, which can serve as a solid foundation for future research endeavors. Additionally, the data mining of the transcriptome in the regeneration zone of the meniscus has provided us with a wealth of valuable information. This includes unique changes in the degree of immune infiltration following meniscus transplantation, infiltration of inflammatory factors, and activation of MMP13. These factors are deemed to be crucial potential tissue repair mechanisms [42-44] . Exploring these mechanisms represents a highly significant direction for our further investigation into how to promote the late-stage repair of meniscus injuries. There are some limitations of this research. This study only investigated the morphological alterations at the 6-week and 12-week marks following meniscus transplantation. Additional research is imperative to ascertain the long-term healing outcomes and to gain a more comprehensive understanding of the sustained efficacy of the transplantation procedure. 5. Conclusion This study confirmed the advantages of PMAT in reducing inflammation, delaying degeneration and protecting cartilage, and revealed the related molecular mechanisms. These findings provide a new choice for the clinical treatment of meniscus injury, and lay a foundation for the study of the molecular mechanism and long-term efficacy of meniscus repair. Declarations Funding The Natural Science Foundation of China (No. 82102610, 52273119); Research project of Fujian Medical University Union Hospital (No. 2024XH032, 2024XH034); Chongqing Natural Science Foundation Key Project (No. CSTB2023NSCQ-LZX0018); Chongqing medical scientific research project-Joint project of Chongqing Health Commission and Science and Technology Bureau (No. 2024GDRC006); The Science and Technology Research Project of Chongqing Education Commission (No. KJQN202200404). Ethics declaration All experimental protocols involving animal subjects in this study adhered to the guidelines outlined in the 8th Edition of the Guide for the Care and Use of Laboratory Animals (National Research Council, 2011) and received formal approval from the Institutional Animal Care and Use Committee (IACUC) of Chongqing Medical University (Approval No. IACUC-CQMU-2023-0038). The authors hereby affirm the absence of any competing interests related to this publication. In accordance with ethical research standards, all raw data, analytical methods, and experimental materials have been fully documented. This study was conducted in strict compliance with all applicable national regulations and institutional policies governing animal experimentation, with particular emphasis on minimizing animal distress and optimizing welfare outcomes throughout the research process. References Gee SM, Posner M. Meniscus Anatomy and Basic Science. 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Am J Sports Med . 2021;49(12):3279-3286. doi:10.1177/03635465211036441. Fan BS, Ye J, Xu BB, et al. Study on feasibility of the partial meniscal allograft transplantation. Clin Transl Med . 2022;12(1):e701. doi:10.1002/ctm2.701. Bąkowski P, Mieloch AA, Porzucek F, et al. Meniscus repair via collagen matrix wrapping and bone marrow injection: clinical and biomolecular study. Int Orthop . 2023;47(10):2409-2417. doi:10.1007/s00264-023-05711-2. Aimono Y, Endo K, Sekiya I. Cellular senescence contributes to spontaneous repair of the rat meniscus. Aging Cell . 2025;24(2):e14385. doi:10.1111/acel.14385. Nakamura K, Kitahashi T, Kogawa R, Yoshino Y, Ogura I. Definition of Synovial Mesenchymal Stem Cells for Meniscus Regeneration by the Mechanism of Action and General Amp1200 Gene Expression. Int J Mol Sci . 2024;25(19):10510. Published 2024 Sep 29. doi:10.3390/ijms251910510. Monibi FA, Pannellini T, Croen B, Otero M, Warren R, Rodeo SA. Targeted transcriptomic analyses of RNA isolated from formalin-fixed and paraffin-embedded human menisci. J Orthop Res . 2022;40(5):1104-1112. doi:10.1002/jor.25153. Lim YS, Tang BL. The Evi5 family in cellular physiology and pathology. FEBS Lett . 2013;587(12):1703-1710. doi:10.1016/j.febslet.2013.04.036. Cai T, Zhou J, Zeng Y, et al. EVI5 is an oncogene that regulates the proliferation and metastasis of NSCLC cells. J Exp Clin Cancer Res . 2020;39(1):84. Published 2020 May 11. doi:10.1186/s13046-020-01585-z. Kim SH, Lipinski L, Pujol N. Meniscal Allograft Transplantation With Soft-Tissue Fixation Including the Anterior Intermeniscal Ligament. Arthrosc Tech . 2019;9(1):e137-e142. Published 2019 Dec 24. doi:10.1016/j.eats.2019.09.015. McCulloch PC, Dolce D, Jones HL, et al. Comparison of Kinematics and Tibiofemoral Contact Pressures for Native and Transplanted Lateral Menisci. Orthop J Sports Med . 2016;4(12):2325967116674441. Published 2016 Dec 17. doi:10.1177/2325967116674441. Stone AV, Loeser RF, Vanderman KS, Long DL, Clark SC, Ferguson CM. Pro-inflammatory stimulation of meniscus cells increases production of matrix metalloproteinases and additional catabolic factors involved in osteoarthritis pathogenesis. Osteoarthritis Cartilage . 2014;22(2):264-274. doi:10.1016/j.joca.2013.11.002. Qiong J, Xia Z, Jing L, Haibin W. Synovial mesenchymal stem cells effectively alleviate osteoarthritis through promoting the proliferation and differentiation of meniscus chondrocytes. Eur Rev Med Pharmacol Sci . 2020;24(4):1645-1655. doi:10.26355/eurrev_202002_20338. Yoon S, Min Y, Park C, et al. Innate Immune Response Analysis in Meniscus Xenotransplantation Using Normal and Triple Knockout Jeju Native Pigs. Int J Mol Sci . 2022;23(18):10416. Published 2022 Sep 8. doi:10.3390/ijms231810416. Tables Table.1 Gross view PMAT group TMAT group 6W 12W 6W 12W Healing 0 0 0 0.67 Osteophyte 0 0.33 0.33 0.33 Shrinking 0 0.33 0.67 1.33 Protrusion 0 0 0.33 0.67 Total 0 0.67 1.33 3 PMAT: partial meniscus allograft transplantation. TMAT: total meniscus allograft transplantation. Table 2. Average IOD results Group IOD Control 0.12060163 PMAT 6W 0.11821790 PMAT 12W 0.11666689 TMAT 6W 0.09507581 TMAT 12W 0.09274914 IOD: Integral Optical Density. PMAT: partial meniscus allograft transplantation. TMAT: total meniscus allograft transplantation. Additional Declarations No competing interests reported. Supplementary Files SupplementaryFigureLegends.docx FigureS1.tif FigureS2.tif FigureS3.tif Cite Share Download PDF Status: Published Journal Publication published 26 Dec, 2025 Read the published version in European Journal of Medical Research → Version 1 posted Editorial decision: Revision requested 16 Oct, 2025 Reviews received at journal 23 Aug, 2025 Reviews received at journal 15 Aug, 2025 Reviewers agreed at journal 10 Aug, 2025 Reviewers agreed at journal 26 Jul, 2025 Reviewers invited by journal 17 Jul, 2025 Editor assigned by journal 16 Jun, 2025 Submission checks completed at journal 16 Jun, 2025 First submitted to journal 12 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6881658","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":487331465,"identity":"d67c2713-f1f5-4faa-9c4d-28378f09f32e","order_by":0,"name":"Hao Tan","email":"","orcid":"","institution":"The Affiliated Dazu Hospital of Chongqing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hao","middleName":"","lastName":"Tan","suffix":""},{"id":487331466,"identity":"2f6481b0-0e6a-419f-9863-2f49a4262951","order_by":1,"name":"Hao Qin","email":"","orcid":"","institution":"the First Affiliated Hospital of Chongqing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hao","middleName":"","lastName":"Qin","suffix":""},{"id":487331467,"identity":"2b137e68-0906-4169-9344-63508a625fbf","order_by":2,"name":"Yu Chen","email":"","orcid":"","institution":"the First Affiliated Hospital of Chongqing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yu","middleName":"","lastName":"Chen","suffix":""},{"id":487331474,"identity":"2369aa79-461a-412b-b8a8-2c0b629a2e8c","order_by":3,"name":"Enrun Wang","email":"","orcid":"","institution":"the First Affiliated Hospital of Chongqing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Enrun","middleName":"","lastName":"Wang","suffix":""},{"id":487331475,"identity":"383eefb7-bb02-4eb6-b028-eaaf2a1a4d63","order_by":4,"name":"Aiguo Zhou","email":"","orcid":"","institution":"the First Affiliated Hospital of Chongqing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Aiguo","middleName":"","lastName":"Zhou","suffix":""},{"id":487331476,"identity":"9ffcd4c8-3d9e-4cc0-b4ee-b815567c3877","order_by":5,"name":"Chengjie Lian","email":"","orcid":"","institution":"Fujian Medical University Union Hospital","correspondingAuthor":false,"prefix":"","firstName":"Chengjie","middleName":"","lastName":"Lian","suffix":""},{"id":487331481,"identity":"091c752f-a944-444e-aefa-25705b9ee857","order_by":6,"name":"Hua Zhang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIiWNgGAWjYDACCSBmbGBg4Gc+kMAAZROpRbItgVQtBsfAOojQIj+7+dnDrzsOyxsfY3i6mYfBRnbDAeZnD/BpYZxzzNxY9sxhw23HGNJu8zCkGW84wGZugE8Ls0SCmbRk22HGbfcbQFoOJ244wMMmgU8Lm0T6N5AW+81tYFv+E9bCI5FjJvmxDWg4G1jLAcJaJCRyyqQZ29KTZwD9cnOOQbLxzMNsZni1yM9I3yb5s83atr+NJ+3Gmwo72b7jzc/wagEBZh6IGxOAsQPiElIPBIw/wBT7ASLUjoJRMApGwUgEAJouSpJFPsGmAAAAAElFTkSuQmCC","orcid":"","institution":"Fujian Medical University Union Hospital","correspondingAuthor":true,"prefix":"","firstName":"Hua","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2025-06-12 15:08:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6881658/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6881658/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s40001-025-03574-4","type":"published","date":"2025-12-26T15:57:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":87254988,"identity":"e3e9195f-e64e-458d-8f9b-0de1cafdf904","added_by":"auto","created_at":"2025-07-22 05:42:19","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":749374,"visible":true,"origin":"","legend":"\u003cp\u003eGross and microscopic observations of meniscus after implantation. (A) Gross View of the meniscus in normal, PMAT, and TMAT groups at 6w and 12w post-operation. (B) H\u0026amp;E and Safranin staining of meniscus. Scale bars: 5 mm (Gross View), 50 μm (HE and Safranin).\u003c/p\u003e","description":"","filename":"Figure1.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/f48f71055dcea91d9c0c21d9.jpg"},{"id":87254986,"identity":"0f3bd90d-7e1c-4821-9902-6dcb9ab1a386","added_by":"auto","created_at":"2025-07-22 05:42:19","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":248669,"visible":true,"origin":"","legend":"\u003cp\u003e(A) Rodeo and (B) Ishida scores assessing graft morphology and healing. *P \u0026lt; 0.05.\u003c/p\u003e","description":"","filename":"Figure2.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/668041b898f7bf0d72e2e330.jpg"},{"id":87254991,"identity":"186a5f2f-f1fe-47d7-b56e-7bb8f8b40a5d","added_by":"auto","created_at":"2025-07-22 05:42:19","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":993382,"visible":true,"origin":"","legend":"\u003cp\u003ePolarized Sirius red and Immunohistochemical (IHC) staining of meniscus in normal, PMAT, and TMAT groups at 6w and 12w post-operation. (A) PR staining of meniscus under a polarized light microscope. (B) IHC staining of meniscus using COL-1, COL-2, MMP-9, MMP-13. Scale bars: 50 μm.\u003c/p\u003e","description":"","filename":"Figure3.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/48affa7a9787e4b3783975c5.jpg"},{"id":87255380,"identity":"a1469a9c-4792-4775-b187-a81cd364ea6c","added_by":"auto","created_at":"2025-07-22 05:50:19","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":548750,"visible":true,"origin":"","legend":"\u003cp\u003eScanning electron microscope images of regional variations in the ultrastructure of the implants in the PMAT group, TMAT group and control group. (A) SEM images under low magnification. (B) SEM images under high magnification. Scale bars: 5 μm (low magnification), 1 μm (high magnification).\u003c/p\u003e","description":"","filename":"Figure4.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/0661d24afd64fe2f864c02d1.jpg"},{"id":87255381,"identity":"6757f622-ef09-4a50-b76d-760e7aff0190","added_by":"auto","created_at":"2025-07-22 05:50:19","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":833203,"visible":true,"origin":"","legend":"\u003cp\u003eGross and microscopic observations of Tibial plateau (TP) and Femoral condyle (FC) after meniscus implantation. P6W: PMAT after 6 weeks; P12W: PMAT after 12 weeks; T6W: TMAT after 6 weeks; T12W: TMAT after 12 weeks; M6W: meniscectomy after 6 weeks; M12W: meniscectomy after 12 weeks.\u003c/p\u003e","description":"","filename":"Figure5.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/b57c4870c5965c56597f0e71.jpg"},{"id":87254992,"identity":"2a09ffcb-8e98-472f-ac26-818360355b9f","added_by":"auto","created_at":"2025-07-22 05:42:19","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":151370,"visible":true,"origin":"","legend":"\u003cp\u003eMankin scores assessing cartilage degeneration. **\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.01, ***\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001.\u003c/p\u003e","description":"","filename":"Figure6.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/1e2ff60cfb13416059cddaef.jpg"},{"id":87254989,"identity":"76b57eba-4e4a-4293-b37b-6528a4df1f31","added_by":"auto","created_at":"2025-07-22 05:42:19","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":1195014,"visible":true,"origin":"","legend":"\u003cp\u003eGene expression analysis results of meniscal samples from TMAT groups compared to the control group at 6 weeks and 12 weeks post-operation. (A) and (B) show heatmaps of Pearson correlation coefficients. (C) and (D) shows volcano plots displaying differentially expressed genes, with the x-axis as log2 (Fold Change) and the y-axis as -log10 (\u003cem\u003eP\u003c/em\u003e-value). (E - H) illustrate functional enrichment analyses, presenting the top GO terms related to the differentially expressed genes.\u003c/p\u003e","description":"","filename":"Figure7.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/5f81317512298b65df78e442.jpg"},{"id":87254994,"identity":"642e9a73-69e4-4471-8b9a-2aa1efef9486","added_by":"auto","created_at":"2025-07-22 05:42:19","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":771365,"visible":true,"origin":"","legend":"\u003cp\u003eDifferential variable shear result plot of (A) SFXN4, (B) CPLANE1, (C) EVI5 and (D) PTGR1. Reads aligned across exons are represented using arcs connecting exon junction boundaries. The thickness of the arc is directly proportional to the number of reads aligned to the junction. At the same time, the number on the arc indicates the number of junction reads, and the gene and inclevel value of the alternative splicing event of each sample are marked in the upper right; Red and orange represent different samples, and the inclusion level value represents the ratio of the total expression of exon inclusion isoform in the two isoforms, which can directly show the expression differences of alternative splicing events in different samples.\u003c/p\u003e","description":"","filename":"Figure8.tif.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/eb4ce02450f0fe0c6153166e.jpg"},{"id":99172209,"identity":"0edd25ec-25d1-4541-8d1e-9dfb38c5f612","added_by":"auto","created_at":"2025-12-29 16:00:08","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6200487,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/3df33ac1-bddb-4c76-a352-b643d2498a48.pdf"},{"id":87254985,"identity":"69ca20aa-d67e-49df-adf5-1f599fc8f7ec","added_by":"auto","created_at":"2025-07-22 05:42:19","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":19454,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryFigureLegends.docx","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/a9eeca6331969b0794bbf317.docx"},{"id":87254995,"identity":"4f62f2e9-ca09-4d4a-a46a-53c3c00e8ed6","added_by":"auto","created_at":"2025-07-22 05:42:22","extension":"tif","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":54394740,"visible":true,"origin":"","legend":"","description":"","filename":"FigureS1.tif","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/d5bacdaf9dd4d3fb8e2137ac.tif"},{"id":87254996,"identity":"16de5a03-d05a-49f1-bdfe-328643d9aab7","added_by":"auto","created_at":"2025-07-22 05:42:28","extension":"tif","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":196993470,"visible":true,"origin":"","legend":"","description":"","filename":"FigureS2.tif","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/95e6b389e7dd8cac6ab8e6b2.tif"},{"id":87254997,"identity":"030f3348-fc93-438e-878f-5f11a843822c","added_by":"auto","created_at":"2025-07-22 05:42:29","extension":"tif","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":197407351,"visible":true,"origin":"","legend":"","description":"","filename":"FigureS3.tif","url":"https://assets-eu.researchsquare.com/files/rs-6881658/v1/5ef3f99618635224724238af.tif"}],"financialInterests":"No competing interests reported.","formattedTitle":"Partial Meniscus Allograft Transplantation Preserving the Recipient’s Anterior Root: A Comparative Study in a Rabbit Model","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe meniscus is an essential part of the knee joint, responsible for stress transmission, shock absorption, joint stability, proprioception, and lubrication of the knee \u003csup\u003e[1-3]\u003c/sup\u003e. The articular surfaces of the femoral condyle and tibial plateau can achieve optimal joint congruence through the characteristic concave-convex structure of the meniscus, increasing the joint contact area and enhancing knee stability \u003csup\u003e[4]\u003c/sup\u003e. However, the meniscus is highly susceptible to injury, with an incidence rate of up to 14% \u003csup\u003e[5]\u003c/sup\u003e. In cases of meniscus injury, arthroscopic suturing repair is preferred. However, for severely damaged menisci or those with poor blood supply, meniscectomy and reshaping are the only viable options \u003csup\u003e[6,7]\u003c/sup\u003e. Research indicates that excision of the medial and lateral menisci results in a 100%-300% increase in the contact stress in the respective knee compartments, thereby accelerating the progression of knee osteoarthritis \u003csup\u003e[8]\u003c/sup\u003e. Meniscus transplantation is a clinically well-accepted choice for young patients with active lifestyles after total meniscectomy, or for those who continue to experience knee symptoms after total meniscectomy \u003csup\u003e[9]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eCurrent meniscus transplantation techniques include allograft meniscus transplantation and artificial meniscus transplantation. Artificial meniscus materials include synthetic implants and tissue-engineered menisci. Synthetic implants, including collagen meniscus implants (CMI) and polyurethane polymer implants (Actifit), can only be used for the repair of partial meniscal defects \u003csup\u003e[10]\u003c/sup\u003e.\u0026nbsp;Replacement meniscus implants, such as NUsurface, are used for meniscus reconstruction following total meniscectomy, but their clinical application is still limited, and the postoperative efficacy is not well established \u003csup\u003e[11]\u003c/sup\u003e.\u0026nbsp;Tissue-engineered menisci are expected to more effectively reconstruct the meniscus\u0026apos;s heterogeneous structure and yield better long-term prognoses, although they are currently in the preclinical trial stage \u003csup\u003e[12,13]\u003c/sup\u003e.\u0026nbsp;Clinical application of allograft meniscus transplantation has become more widespread, yielding favorable cartilage protection outcomes post-surgery, and resulting in high patient satisfaction \u003csup\u003e[14-19]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eNotably, many studies have indicated that the incidence of meniscus injuries differs across regions, with the occurrence of posterior root injuries being higher than that of the anterior root in both acute and chronic knee injuries \u003csup\u003e[20-22]\u003c/sup\u003e. Additionally, we also observed that most patients have meniscus tears in the posterior root, with the remaining anterior root maintaining a relatively good quality. Thus, in meniscus transplantation, there appears to be an opportunity to retain the complete anterior root of the recipient\u0026apos;s meniscus. Furthermore, research has shown that after meniscus transplantation, atrophy of the graft\u0026apos;s anterior root is one of the most common signs of graft degeneration \u003csup\u003e[23-25]\u003c/sup\u003e. In the postoperative follow-up of patients undergoing allograft meniscus transplantation in our department, we observed that 23 out of 75 patients exhibited varying degrees of anterior root atrophy at different postoperative time points. Although the cause and mechanism of anterior root atrophy remain unclear, preserving the recipient\u0026rsquo;s original meniscus anterior root seems promising in slowing the rate of anterior root atrophy post-transplantation, potentially extending the graft\u0026rsquo;s lifespan and delaying the progression of osteoarthritis.\u003c/p\u003e\n\u003cp\u003eAt present, there are some pre-clinical studies on the repair of meniscus fragments and the transplantation of only the meniscus posterior root \u003csup\u003e[26,27]\u003c/sup\u003e. However, no studies have explored the postoperative efficacy and the morphological changes of the meniscus following partial meniscus allograft transplantation with preservation of the recipient\u0026rsquo;s anterior root. This study aims to preserve the recipient\u0026apos;s anterior root during allograft meniscus transplantation and perform partial meniscus transplantation. A rabbit model was used in this study to evaluate whether the partial meniscus allograft transplantation group (PMAT), with preservation of the anterior root, will more effectively preserve the physiological function of the meniscus and slow the degeneration of the meniscus allograft and articular cartilage when compared to the total meniscus allograft transplantation group (TMAT).\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cp\u003e\u003cstrong\u003e2.1\u0026nbsp;Research approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll animal experimentation procedures in this study were conducted in accordance with the 8th edition of the Guide for the Care and Use of Laboratory Animals published by the National Research Council and received approval from the Institutional Animal Care and Use Committee of Chongqing Medical University (Approval No. IACUC-CQMU-2023-0038).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Animal model\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e18 female New Zealand rabbits (3.0–3.5 kg) were procured from the animal laboratory at Chongqing Medical University and randomly assigned to different groups. In all rabbits, a 3-cm medial parapatellar incision was made to expose the medial knee compartment. The medial collateral ligament and joint capsule were incised, and the medial meniscus was isolated by transecting its roots at the tibial plateau. The excised menisci were cleaned with sterile saline. In the DMM group, menisci were stored at -80\u0026nbsp;°C in vacuum bags without cryoprotectant. In the TMAT group, menisci were trimmed, transplanted into another recipient within 2 hours, and sutured to the joint capsule. In the PMAT group, the meniscus was harvested in a manner similar to the previous method. At this point, the junction between the anterior horn and body of the right medial meniscus, as well as the posterior horn attachment to the tibial plateau, were transected to separate the medial meniscus. Following the above steps, the medial collateral ligament was sutured using 2-0 non-absorbable sutures, and the joint capsule and skin were subsequently closed. The wound was covered with sterile gauze and bandaged. Within 3 days post-surgery, antibiotics were administered intramuscularly, wound dressings were changed to prevent infection. No plaster cast was applied, and the recipient was allowed to move freely in a standard housing cage. Euthanasia was performed at 6 weeks and 12 weeks post-surgery. Gross images of the surgical side knee joint were taken, and the meniscus and articular osteochondral tissue post-transplantation were collected for subsequent analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Hematoxylin and eosin (H\u0026amp;E) staining\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe obtained meniscus and osteochondral tissue specimens were fixed in 4% neutral formalin for 48 hours and decalcified using a 10% EDTA solution for 1 month. After washing overnight with distilled water, the decalcified specimens were dehydrated using ethanol of varying concentrations, cleared with xylene, and then embedded in paraffin. Using a paraffin microtome, 4 μm thick sections were made along the coronal plane of the femoral condyle and tibial plateau. The sections were stained with hematoxylin-eosin and observed under a microscope (Olympus).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Safranin O staining\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sections were deparaffinized in xylene and rehydrated using a gradient of ethanol. The sections were stained with Safranin O solution for 5 minutes, then differentiated in acidic ethanol for 15 seconds, and washed with running water. The sections were stained with Picrosirius Red solution for 3 minutes, then quickly dehydrated with anhydrous ethanol three times. After mounting with neutral resin, the sections were examined under an optical microscope.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.5 Picrosirius Red (PR) staining\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParaffin sections are routinely deparaffinized with xylene and hydrated through a gradient of ethanol. Sections were stained following the instructions of the Picrosirius Red reagent (Solarbio, Beijing, China). After staining, the sections were dehydrated and mounted with neutral resin. They were then observed under a polarized light microscope, and the integrated optical density (IOD) was measured using ImageJ.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.6 Immunohistochemistry (IHC) staining\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sections were deparaffinized with xylene and hydrated using a gradient of ethanol. The slides were incubated with hydrogen peroxide to inhibit endogenous peroxidase activity, followed by blocking nonspecific binding sites with goat serum. Next, an appropriate volume of the primary antibody was added and incubated overnight at 4°C. On the second day, the samples were incubated with secondary and tertiary antibodies at room temperature for 30 minutes, then stained with diaminobenzidine and counterstained with hematoxylin. Immunohistochemical images were subsequently taken under a light microscope.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.7 Scanning electron microscope (SEM) examination\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe meniscus allografts obtained at 12 weeks from the control group (The entire meniscus obtained from the M group), PMAT group, and TMAT group were cut into sizes of ≤ 1 cm² in area and ≤ 5 mm in thickness. The trimmed grafts were rinsed with physiological saline, placed in fixative, and stored at 4°C before undergoing scanning electron microscopy. The ultrastructure was observed using a Hitachi S-3000N scanning electron microscope (Hitachi High-Technologies Corporation, Japan).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.8 RNA extraction and transcriptome sequencing\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTotal RNA was extracted from the New Zealand rabbit meniscus tissue using Trizol reagent (Takara, Japan). After assessing RNA purity and integrity, sequencing libraries were prepared using the Illumina® RNA Library Preparation Kit (NEB, USA) and sequenced on the Illumina platform. Gene expression levels were estimated using StringTie (v2.1.6), and differential expression analysis was performed using the DESeq2 R package (v1.32.0), with a \u003cem\u003eP\u003c/em\u003e-value threshold of \u0026lt; 0.05 for selecting differentially expressed genes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.9 Functional enrichment analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEnrichment analysis (GSEA) for Gene Ontology (GO), and Disease Ontology (DO) was performed using the clusterProfiler (4.0.0) R package, with a \u003cem\u003eP\u003c/em\u003e-value threshold of \u0026lt; 0.05 for statistically significant results.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.10 Evaluation of implants and joint cartilages\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFollowing euthanasia of the recipient animals, the knee joint was opened, and photographs of the joint capsule cavity were taken. The graft healing (0 = healed, 1 = not healed), shrinkage (0 = none, 1 = anterior or posterior horn, 2 = both anterior and posterior horns, 3 = entire graft), extrusion (0 = none, 1 = anterior or posterior horn, 2 = entire graft), and osteophyte formation (0 = none, 1 = femoral condyle or tibial plateau, 2 = both femoral condyle and tibial plateau) were evaluated visually. Histological quantitative assessment of graft morphology and healing was performed using the Rodeo and Ishida scoring systems \u003csup\u003e[28,29]\u003c/sup\u003e. Articular cartilage damage was evaluated histologically using the Mankin scoring system\u003csup\u003e\u0026nbsp;[30]\u003c/sup\u003e. All specimens were assessed in a double-blind manner by two researchers, with the final results being the average value.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.11 Statistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll statistics are presented as mean ± SD. Data analysis was performed using nonparametric tests. All data analyses were performed using SPSS statistical software (version 25.0, ibm-spss, Armonk, NY). A \u003cem\u003eP\u003c/em\u003e value less than 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"3. Results","content":"\u003cp\u003e\u003cstrong\u003e3.1 Gross evaluation of implants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the rabbits that underwent the surgical procedure experienced smooth recoveries, with no significant alterations in weight, infections, or other complications. At 6 and 12 weeks postoperatively, an overall evaluation was conducted on the implants of TMAT and PMAT groups. From the gross view, the TMAT group's implants received significantly lower scores compared to the PMAT group in terms of implant positioning, surface characteristics, tissue integration, and synovial response (Table 1). The majority of these implants had integrated well with the normal attachment sites, showing no evidence of fractures or gaps. Within the PMAT group, all the six implants examined displayed a healthy, normal appearance, whether at 6 weeks or 12 weeks postoperatively. And there was no noticeable synovial hyperplasia or tears in the implants (Figure 1A).\u0026nbsp;In the TMAT group, two of the implants were observed to be slightly protruding, with evidence of synovial proliferation. Additionally, the implants in the TMAT group were notably softer, and their surfaces exhibited a rough texture. Besides, after 12 weeks of surgery, there was obvious dissolution in the anterior foot of the meniscus in the TMAT group.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Histological evaluation of implants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe composition and spatial distribution of collagen in regenerated meniscus was analysed by HE and\u0026nbsp;Safranin O-Fast green staining. As shown in Figure 1B, at both 6 weeks and 12 weeks post-surgery, the anterior root of meniscus in the PMAT group exhibited similar shapes and collagen fiber distribution to those of normal tissues. While in the TMAT group, the number of fibrochondrocytes in the local collagen fibres of the donor meniscus decreased. Especially in the 12-week group, the collagen fibers in the meniscus showed significant looseness and deformation. The transplanted meniscus has a similar distribution of collagen cells and chondrocytes as the normal meniscus, but low cell density areas were still observed in all implants within the TMAT group. The PMAT group outperformed the TMAT group on the Ishida scoring system (Figure 2A). but no significant difference was observed between the two groups when assessed using the Rodeo scoring system (Figure 2B).\u003c/p\u003e\n\u003cp\u003eAs shown in Figure 3A, quantitative analysis of collagen content was performed using polarized Sirius red light staining, and red fibres represent COL-1, while green fibres represent COL-3. Compared with PMAT group and Control group, both COL-1 and COL-3 showed a significant reduction in TMAT group, which was also validated on the IOD (integrated optical density) of each group (Table 2). Immunohistochemical staining showed that the PMAT group and the Control group exhibited similar levels of collagen fibers and matrix metalloproteinases (figure 3B). In contrast, the TMAT group showed significantly reduced expression of COL-1 and COL-2, while displaying elevated levels of MMP-9 and MMP-13.\u003c/p\u003e\n\u003cp\u003eIn SEM image (figure 4), the Control and PMAT groups showed intact meniscus tissues with tightly - arranged fibers and uniform pores under low magnification, and clear fiber structures with even diameters and smooth surfaces under high magnification. But the TMAT group presented damaged fiber structures, loosely-arranged fibers, enlarged and uneven pores under low magnification, and smaller fiber diameters, rough surfaces, and weakened fiber connections under high magnification, indicating its poor performance.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Evaluation of cartilage\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the gross look of articular cartilage (Figure 5), the PMAT group exhibited no significant articular cartilage tears or degeneration. In contrast, the TMAT group showed loss of cartilage surface luster, appearing rough with varying degrees of damage. The DMM group showed the most severe impairment, with visible exposure of the subchondral bone and cracks on the cartilage surface. cracks appeared on the cartilage surface of the TMAT group, accompanied by an uneven distribution of chondrocytes. Safranin O staining showed a moderate reduction, with irregular changes on the surface of the femoral condyle and tibial plateau. In the PMAT group, the chondral layers were distinct, the tidemark was intact, and cellularity within each stratum was normal. Nuclei showed deep staining, and Safranin O staining was pronounced, closely resembling the Control group. Histological evaluation and Mankin scoring indicated the most severe cartilage damage in the DMM group, followed by the TMAT group (Figure 6).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Analysis of meniscus transcriptome by RNA sequencing\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRNA sequencing was conducted on meniscal samples at 6 and 12 weeks following total meniscus transplantation, as well as in a control group, to assess alterations in gene expression. A total of 130 genes showed significant expression changes in all three groups compared to each other, suggesting their potential utility as critical targets in mechanistic studies of meniscal regeneration (Figure S1).\u0026nbsp;The analysis of the Pearson similarity heatmap demonstrates a significant correlation among the three groups of samples. This indicates that the variables within these groups are closely related, suggesting potential shared underlying patterns or mechanisms (Figure 7A, 7B). The heatmaps in Figures S2 and S3 show the upregulation and downregulation levels of the differentially expressed genes selected. Comparing with the Control Group, genes such as KRT78, COL1A1, MMP13 and FNDC1 were significantly upregulated after 6 weeks of transplantation. Conversely, genes like KLB, UVRAG, and CLEC3A exhibited marked downregulation (Figure 7C). While after 12 weeks of transplantation, ATP6V0DZ, GPNMB, and DKK3 were significantly upregulated, and significant downregulation of LEPR, CXCL5, and IGFBP5 was observed (Figure 7D). Cluster analysis of the differentially expressed genes (DEGs) demonstrated excellent intra-group sample consistency and significant inter-group differences. Gene Ontology (GO) analysis revealed dynamic functional changes over time. At 6 weeks post-transplantation, downregulated pathways included membrane and integral component of membrane, while upregulated pathways included immune response and microtubule-based movement (Figure 7E, 7F). At 12 weeks post-transplantation, downregulated pathways shifted to protein binding and plasma membrane, while extracellular space and cell surface remained upregulated (Figure 7G, 7H). These results highlight the temporal dynamics of gene expression following transplantation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFor alternative splicing events with significant differences in expression, the project visualizes them using rmats2sashimiplot. Compared with the normal meniscus, the inclusion levels of SFXN4 and CPLANE1 were significantly reduced after 6 weeks of transplantation (Figure 8A, 8B), and those of EVI5 and PTGR1 decreased after 12 weeks of transplantation (Figure 8C, 8D). This is of significant importance for identifying targets related to meniscus healing, degeneration, and metabolism in subsequent research.\u0026nbsp;\u003c/p\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eIn this study, our research showed that the PMAT group had less wear and degeneration of the anterior root post-surgery compared to the TMAT group, with better preservation of collagen fiber content and structure.\u0026nbsp;Additionally, the PMAT group showed less local inflammatory response, and the meniscus allograft demonstrated superior cartilage protection. It further highlighted the effect of the sequential expression of genes like SFXN4 and CPLANE1 on meniscus tissue repair and regeneration after transplantation. Our study provides reliable preclinical evidence for the improvement of future meniscus transplantation surgical techniques. Our study will offer additional theoretical support and alternative approaches for the advancement of clinical meniscus transplantation techniques.\u003c/p\u003e\n\u003cp\u003eOur study demonstrated that the PMAT group exhibited superior outcomes in meniscus morphology and cartilage protection compared to the TMAT group. This aligns with prior findings, such as Strauss et al.\u0026apos;s study showing partial healing of meniscus fragment grafts in sheep after 90 days\u003csup\u003e\u0026nbsp;[31]\u003c/sup\u003e, and Haber et al.\u0026apos;s work restoring knee joint biomechanics in cadaver specimens \u003csup\u003e[32]\u003c/sup\u003e. Additionally, Fan et al. observed reduced inflammation, improved graft healing, and superior biomechanical performance in Beagle dogs following partial meniscus transplantation, with specific genes like KNTC1 and RAD51AP1 implicated in tissue repair \u003csup\u003e[33]\u003c/sup\u003e. These results may stem from three key factors: (1) PMAT preserved native meniscus tissue in the anterior root, reducing inflammation and immune rejection, as evidenced by lower post-surgical MMP-9 and MMP-13 levels; (2) retention of the native anterior root and roots ensured proper graft positioning, restoring biomechanical effects and enhancing cartilage protection; and (3) preserved soft tissue connections maintained blood supply to the anterior root, delaying degeneration and optimizing meniscus morphology. These findings underscore the clinical potential of PMAT in improving long-term outcomes and reducing complications.\u003c/p\u003e\n\u003cp\u003eCurrent understanding of molecular mechanisms governing meniscus regeneration remains limited, necessitating comprehensive exploration of regulatory biomarkers to enhance transplantation outcomes \u003csup\u003e[34,35]\u003c/sup\u003e. Integrated transcriptomic and proteomic analyses reveal distinct expression patterns of key molecules in post-surgical repair processes \u003csup\u003e[36,37]\u003c/sup\u003e. Notably, MMP13 exhibits significant upregulation across immunohistochemical and genomic assessments, suggesting its pathological role in extracellular matrix (ECM) degradation through excessive cleavage of collagen fibers, thereby impairing cellular adhesion, proliferation, and differentiation in the anterior root region. Concurrently, SFXN4 and CPLANE1 demonstrate marked downregulation at 6-week post-operation, potentially reflecting suppressed collagenocyte metabolic activity and proliferative capacity under persistent inflammatory conditions characterized by elevated MMP9/MMP13 expression. Longitudinal analysis identifies temporal regulatory patterns, with EVI5 downregulation at 12 weeks indicating cell cycle dysregulation through impaired APC/C-Emi1 complex stabilization, while diminished PTGR1 expression suggests potential dual impacts on eicosanoid-mediated inflammation modulation and compromised matrix remodeling \u003csup\u003e[38,39]\u003c/sup\u003e. These findings collectively highlight dynamic molecular interplay between matrix metalloproteinase activity, cellular metabolic regulation, and inflammatory signaling during meniscus repair, though precise transcriptional networks and temporal regulatory mechanisms warrant further mechanistic investigation.\u003c/p\u003e\n\u003cp\u003eThe technique of meniscus transplantation has become well-established. Nevertheless, there is a paucity of literature examining how the tissue morphology of the transplanted anterior root alters after allogeneic meniscus transplantation \u003csup\u003e[40,41]\u003c/sup\u003e. Additionally, there is an absence of research assessing its influence on clinical outcomes or investigating potential risk factors. In our study, we utilized rabbit models and applied a variety of MAT techniques to repair meniscus defects. Our study confirmed that the repair efficacy of PMAT technology surpasses that of TMAT technology, which empowers us to proactively delve into the viability of PMAT, thereby delivering enhanced therapeutic outcomes to a broader spectrum of patients, particularly those grappling with meniscus injuries in the anterior root region. Further clinical trials are needed to explore the efficacy of PMAT. Furthermore, we identified the potential gene targets, activated signaling pathways, and cellular functions underlying this advantage, which can serve as a solid foundation for future research endeavors. Additionally, the data mining of the transcriptome in the regeneration zone of the meniscus has provided us with a wealth of valuable information. This includes unique changes in the degree of immune infiltration following meniscus transplantation, infiltration of inflammatory factors, and activation of MMP13. These factors are deemed to be crucial potential tissue repair mechanisms \u003csup\u003e[42-44]\u003c/sup\u003e. Exploring these mechanisms represents a highly significant direction for our further investigation into how to promote the late-stage repair of meniscus injuries.\u003c/p\u003e\n\u003cp\u003eThere are some limitations of this research. This study only investigated the morphological alterations at the 6-week and 12-week marks following meniscus transplantation. Additional research is imperative to ascertain the long-term healing outcomes and to gain a more comprehensive understanding of the sustained efficacy of the transplantation procedure.\u0026nbsp;\u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eThis study confirmed the advantages of PMAT in reducing inflammation, delaying degeneration and protecting cartilage, and revealed the related molecular mechanisms. These findings provide a new choice for the clinical treatment of meniscus injury, and lay a foundation for the study of the molecular mechanism and long-term efficacy of meniscus repair.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Natural Science Foundation of China (No. 82102610, 52273119); Research project of Fujian Medical University Union Hospital (No. 2024XH032, 2024XH034); Chongqing Natural Science Foundation Key Project (No. CSTB2023NSCQ-LZX0018); Chongqing medical scientific research project-Joint project of Chongqing Health Commission and Science and Technology Bureau (No. 2024GDRC006); The Science and Technology Research Project of Chongqing Education Commission (No. KJQN202200404).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics declaration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll experimental protocols involving animal subjects in this study adhered to the guidelines outlined in the 8th Edition of the Guide for the Care and Use of Laboratory Animals (National Research Council, 2011) and received formal approval from the Institutional Animal Care and Use Committee (IACUC) of Chongqing Medical University (Approval No. IACUC-CQMU-2023-0038). The authors hereby affirm the absence of any competing interests related to this publication. In accordance with ethical research standards, all raw data, analytical methods, and experimental materials have been fully documented. This study was conducted in strict compliance with all applicable national regulations and institutional policies governing animal experimentation, with particular emphasis on minimizing animal distress and optimizing welfare outcomes throughout the research process.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGee SM, Posner M. Meniscus Anatomy and Basic Science. Sports Med Arthrosc Rev. 2021;29(3): e18-e23. doi:10.1097/JSA.0000000000000327.\u003c/li\u003e\n\u003cli\u003eRath E, Richmond JC. The menisci: basic science and advances in treatment. \u003cem\u003eBr J Sports Med\u003c/em\u003e. 2000;34(4):252-257. doi:10.1136/bjsm.34.4.252.\u003c/li\u003e\n\u003cli\u003eMakris EA, Hadidi P, Athanasiou KA. 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Meniscal Transplantation in Symptomatic Patients Under Fifty Years of Age: Survivorship Analysis. \u003cem\u003eJ Bone Joint Surg Am\u003c/em\u003e. 2015;97(15):1209-1219. doi:10.2106/JBJS.N.01340.\u003c/li\u003e\n\u003cli\u003eCvetanovich GL, Christian DR, Garcia GH, et al. Return to Sport and Patient Satisfaction After Meniscal Allograft Transplantation. \u003cem\u003eArthroscopy\u003c/em\u003e. 2020;36(9):2456-2463. doi:10.1016/j.arthro.2020.04.034.\u003c/li\u003e\n\u003cli\u003eNaranje S, Mittal R, Nag H, Sharma R. Arthroscopic and magnetic resonance imaging evaluation of meniscus lesions in the chronic anterior cruciate ligament-deficient knee. \u003cem\u003eArthroscopy\u003c/em\u003e. 2008;24(9):1045-1051. doi:10.1016/j.arthro.2008.03.008.\u003c/li\u003e\n\u003cli\u003eClark SC, Pareek A, Hevesi M, et al. High incidence of medial meniscus root/radial tears and extrusion in 253 patients with subchondral insufficiency fractures of the knee. \u003cem\u003eKnee Surg Sports Traumatol Arthrosc\u003c/em\u003e. 2024;32(11):2755-2761. doi:10.1002/ksa.12271.\u003c/li\u003e\n\u003cli\u003eSmith JP 3rd, Barrett GR. Medial and lateral meniscal tear patterns in anterior cruciate ligament-deficient knees. A prospective analysis of 575 tears. \u003cem\u003eAm J Sports Med\u003c/em\u003e. 2001;29(4):415-419. doi:10.1177/03635465010290040501\u003c/li\u003e\n\u003cli\u003eZhang H, Liu X, Wei Y, et al. Meniscal allograft transplantation in isolated and combined surgery. \u003cem\u003eKnee Surg Sports Traumatol Arthrosc\u003c/em\u003e. 2012;20(2):281-289. doi:10.1007/s00167-011-1572-3.\u003c/li\u003e\n\u003cli\u003eKim JM, Bin SI. Meniscal allograft transplantation after total meniscectomy of torn discoid lateral meniscus. \u003cem\u003eArthroscopy\u003c/em\u003e. 2006;22(12):1344-1350.e1. doi:10.1016/j.arthro.2006.07.048.\u003c/li\u003e\n\u003cli\u003eWinkler PW, Wagala NN, Hughes JD, Irrgang JJ, Fu FH, Musahl V. Association Between Meniscal Allograft Tears and Early Surgical Meniscal Allograft Failure. \u003cem\u003eAm J Sports Med\u003c/em\u003e. 2021;49(12):3302-3311. doi:10.1177/03635465211032970.\u003c/li\u003e\n\u003cli\u003eHaber DB, Douglass BW, Arner JW, et al. Biomechanical Analysis of Segmental Medial Meniscal Transplantation in a Human Cadaveric Model. \u003cem\u003eAm J Sports Med\u003c/em\u003e. 2021;49(12):3279-3286. doi:10.1177/03635465211036441.\u003c/li\u003e\n\u003cli\u003eFan BS, Ye J, Xu BB, et al. Study on feasibility of the partial meniscal allograft transplantation. \u003cem\u003eClin Transl Med\u003c/em\u003e. 2022;12(1):e701. doi:10.1002/ctm2.701.\u003c/li\u003e\n\u003cli\u003eRodeo SA, Seneviratne A, Suzuki K, Felker K, Wickiewicz TL, Warren RF. Histological analysis of human meniscal allografts. A preliminary report. \u003cem\u003eJ Bone Joint Surg Am\u003c/em\u003e. 2000;82(8):1071-1082. doi:10.2106/00004623-200008000-00002.\u003c/li\u003e\n\u003cli\u003eStrauss E, Caborn DNM, Nyland J, Horng S, Chagnon M, Wilke D. Tissue healing following segmental meniscal allograft transplantation: a pilot study. \u003cem\u003eKnee Surg Sports Traumatol Arthrosc\u003c/em\u003e. 2019;27(6):1931-1938. doi:10.1007/s00167-019-05355-z.\u003c/li\u003e\n\u003cli\u003ePauli C, Whiteside R, Heras FL, et al. Comparison of cartilage histopathology assessment systems on human knee joints at all stages of osteoarthritis development. \u003cem\u003eOsteoarthritis Cartilage\u003c/em\u003e. 2012;20(6):476-485. doi:10.1016/j.joca.2011.12.018.\u003c/li\u003e\n\u003cli\u003eStrauss E, Caborn DNM, Nyland J, Horng S, Chagnon M, Wilke D. Tissue healing following segmental meniscal allograft transplantation: a pilot study. \u003cem\u003eKnee Surg Sports Traumatol Arthrosc\u003c/em\u003e. 2019;27(6):1931-1938. doi:10.1007/s00167-019-05355-z.\u003c/li\u003e\n\u003cli\u003eHaber DB, Douglass BW, Arner JW, et al. Biomechanical Analysis of Segmental Medial Meniscal Transplantation in a Human Cadaveric Model. \u003cem\u003eAm J Sports Med\u003c/em\u003e. 2021;49(12):3279-3286. doi:10.1177/03635465211036441.\u003c/li\u003e\n\u003cli\u003eFan BS, Ye J, Xu BB, et al. Study on feasibility of the partial meniscal allograft transplantation. \u003cem\u003eClin Transl Med\u003c/em\u003e. 2022;12(1):e701. doi:10.1002/ctm2.701.\u003c/li\u003e\n\u003cli\u003eBąkowski P, Mieloch AA, Porzucek F, et al. Meniscus repair via collagen matrix wrapping and bone marrow injection: clinical and biomolecular study. \u003cem\u003eInt Orthop\u003c/em\u003e. 2023;47(10):2409-2417. doi:10.1007/s00264-023-05711-2.\u003c/li\u003e\n\u003cli\u003eAimono Y, Endo K, Sekiya I. Cellular senescence contributes to spontaneous repair of the rat meniscus. \u003cem\u003eAging Cell\u003c/em\u003e. 2025;24(2):e14385. doi:10.1111/acel.14385.\u003c/li\u003e\n\u003cli\u003eNakamura K, Kitahashi T, Kogawa R, Yoshino Y, Ogura I. Definition of Synovial Mesenchymal Stem Cells for Meniscus Regeneration by the Mechanism of Action and General Amp1200 Gene Expression. \u003cem\u003eInt J Mol Sci\u003c/em\u003e. 2024;25(19):10510. Published 2024 Sep 29. doi:10.3390/ijms251910510.\u003c/li\u003e\n\u003cli\u003eMonibi FA, Pannellini T, Croen B, Otero M, Warren R, Rodeo SA. Targeted transcriptomic analyses of RNA isolated from formalin-fixed and paraffin-embedded human menisci. \u003cem\u003eJ Orthop Res\u003c/em\u003e. 2022;40(5):1104-1112. doi:10.1002/jor.25153.\u003c/li\u003e\n\u003cli\u003eLim YS, Tang BL. The Evi5 family in cellular physiology and pathology. \u003cem\u003eFEBS Lett\u003c/em\u003e. 2013;587(12):1703-1710. doi:10.1016/j.febslet.2013.04.036.\u003c/li\u003e\n\u003cli\u003eCai T, Zhou J, Zeng Y, et al. EVI5 is an oncogene that regulates the proliferation and metastasis of NSCLC cells. \u003cem\u003eJ Exp Clin Cancer Res\u003c/em\u003e. 2020;39(1):84. Published 2020 May 11. doi:10.1186/s13046-020-01585-z.\u003c/li\u003e\n\u003cli\u003eKim SH, Lipinski L, Pujol N. Meniscal Allograft Transplantation With Soft-Tissue Fixation Including the Anterior Intermeniscal Ligament. \u003cem\u003eArthrosc Tech\u003c/em\u003e. 2019;9(1):e137-e142. Published 2019 Dec 24. doi:10.1016/j.eats.2019.09.015.\u003c/li\u003e\n\u003cli\u003eMcCulloch PC, Dolce D, Jones HL, et al. Comparison of Kinematics and Tibiofemoral Contact Pressures for Native and Transplanted Lateral Menisci. \u003cem\u003eOrthop J Sports Med\u003c/em\u003e. 2016;4(12):2325967116674441. Published 2016 Dec 17. doi:10.1177/2325967116674441.\u003c/li\u003e\n\u003cli\u003eStone AV, Loeser RF, Vanderman KS, Long DL, Clark SC, Ferguson CM. Pro-inflammatory stimulation of meniscus cells increases production of matrix metalloproteinases and additional catabolic factors involved in osteoarthritis pathogenesis. \u003cem\u003eOsteoarthritis Cartilage\u003c/em\u003e. 2014;22(2):264-274. doi:10.1016/j.joca.2013.11.002.\u003c/li\u003e\n\u003cli\u003eQiong J, Xia Z, Jing L, Haibin W. Synovial mesenchymal stem cells effectively alleviate osteoarthritis through promoting the proliferation and differentiation of meniscus chondrocytes. \u003cem\u003eEur Rev Med Pharmacol Sci\u003c/em\u003e. 2020;24(4):1645-1655. doi:10.26355/eurrev_202002_20338.\u003c/li\u003e\n\u003cli\u003eYoon S, Min Y, Park C, et al. Innate Immune Response Analysis in Meniscus Xenotransplantation Using Normal and Triple Knockout Jeju Native Pigs. \u003cem\u003eInt J Mol Sci\u003c/em\u003e. 2022;23(18):10416. Published 2022 Sep 8. doi:10.3390/ijms231810416.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003ch3\u003eTable.1 Gross view\u003c/h3\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 31px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 33px;\"\u003e\n \u003cp\u003ePMAT group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 35px;\"\u003e\n \u003cp\u003eTMAT group\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 31px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e6W\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e12W\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e6W\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e12W\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 31px;\"\u003e\n \u003cp\u003eHealing\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 31px;\"\u003e\n \u003cp\u003eOsteophyte\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 31px;\"\u003e\n \u003cp\u003eShrinking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e1.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 31px;\"\u003e\n \u003cp\u003eProtrusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 31px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 16px;\"\u003e\n \u003cp\u003e0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e1.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ePMAT: partial meniscus allograft transplantation. TMAT: total meniscus allograft transplantation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u003c/strong\u003e \u003cstrong\u003eAverage IOD results\u003c/strong\u003e\u003c/p\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 258px;\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003eIOD\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 258px;\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e0.12060163\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 258px;\"\u003e\n \u003cp\u003ePMAT 6W\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e0.11821790\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 258px;\"\u003e\n \u003cp\u003ePMAT 12W\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e0.11666689\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 258px;\"\u003e\n \u003cp\u003eTMAT 6W\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e0.09507581\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 258px;\"\u003e\n \u003cp\u003eTMAT 12W\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 241px;\"\u003e\n \u003cp\u003e0.09274914\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eIOD: Integral Optical Density. PMAT: partial meniscus allograft transplantation. TMAT: total meniscus allograft transplantation.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-medical-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejmr","sideBox":"Learn more about [European Journal of Medical Research](http://eurjmedres.biomedcentral.com)","snPcode":"40001","submissionUrl":"https://submission.nature.com/new-submission/40001/3","title":"European Journal of Medical Research","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Meniscus allograft transplantation, Anterior root, Rabbit model, RNA sequencing","lastPublishedDoi":"10.21203/rs.3.rs-6881658/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6881658/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"This study compared partial (PMAT) and total meniscus allograft transplantation (TMAT) in rabbits, assessing their impact on meniscus function preservation and degeneration delay. In 18 rabbits with induced meniscus defects, PMAT better preserved meniscus morphology, collagen fibers, and showed less inflammation and better cartilage protection than TMAT. Histological staining and RNA sequencing revealed PMAT maintained collagen distribution and certain gene expression patterns closer to normal tissues. These findings suggest PMAT may offer advantages in reducing inflammation, delaying degeneration, and protecting cartilage, providing a potential new clinical approach for meniscus injuries and a basis for further research on meniscus repair mechanisms.","manuscriptTitle":"Partial Meniscus Allograft Transplantation Preserving the Recipient’s Anterior Root: A Comparative Study in a Rabbit Model","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-22 05:42:14","doi":"10.21203/rs.3.rs-6881658/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-16T13:44:07+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-23T12:18:32+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-15T08:50:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"113896174468971918751325363561697841990","date":"2025-08-10T11:45:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250723307679633260921336218677480224170","date":"2025-07-26T11:14:27+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-17T11:29:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-16T07:11:32+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-16T06:52:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Journal of Medical Research","date":"2025-06-12T15:03:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-medical-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejmr","sideBox":"Learn more about [European Journal of Medical Research](http://eurjmedres.biomedcentral.com)","snPcode":"40001","submissionUrl":"https://submission.nature.com/new-submission/40001/3","title":"European Journal of Medical Research","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8d0e32da-a830-4024-ab17-99a60eae670b","owner":[],"postedDate":"July 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-29T15:58:47+00:00","versionOfRecord":{"articleIdentity":"rs-6881658","link":"https://doi.org/10.1186/s40001-025-03574-4","journal":{"identity":"european-journal-of-medical-research","isVorOnly":false,"title":"European Journal of Medical Research"},"publishedOn":"2025-12-26 15:57:00","publishedOnDateReadable":"December 26th, 2025"},"versionCreatedAt":"2025-07-22 05:42:14","video":"","vorDoi":"10.1186/s40001-025-03574-4","vorDoiUrl":"https://doi.org/10.1186/s40001-025-03574-4","workflowStages":[]},"version":"v1","identity":"rs-6881658","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6881658","identity":"rs-6881658","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}