UNASSIGNED: To determine the feasibility of meniscal imaging using virtual monochromatic images obtained through dualenergy computed tomography (DECT) technique, and to determine which keV levels optimise contrast resolution.
UNASSIGNED: All DECT exams were performed on a Discovery CT750 HD system from GE Healthcare. Virtual monochromatic images were reconstructed at 40 keV, 73 keV, 106 keV, and 139 keV. Contrast resolution of the medial and lateral menisci using a 5-point Likert scale at each keV level was determined through a consensus agreement by 2 fellowship-trained musculoskeletal radiologists. Friedman\'s and Wilcoxon signed rank tests were used to compare visualisation scores across different keV levels.
UNASSIGNED: Seventeen knee exams from 10 patients met criteria for inclusion in the study. All patients included in the study cohort were male. The median age of patients was 46 years (interquartile range, 35-53 years). Virtual monochromatic images at 40 keV demonstrated highest contrast resolution of the menisci, with a statistically significant difference between contrast resolution scores at 40 keV and 76 keV, Friedman test: p < 0.0001.
UNASSIGNED: Meniscal imaging is feasible using DECT virtual monochromatic images at low keV levels. Improved contrast resolution at these specified KeV values could pave the way for further research in this field to determine its role in the future as an alternative option for assessment of the menisci in patients with contraindications to MRI or in the setting of a periarticular ferromagnetic foreign body obscuring the field of view.

UNASSIGNED: Meniscal repair has been associated with long-term benefit in patients compared with meniscectomy. As a generalization, meniscal repair in older patients is less likely to be successful, leading to reduced adoption of meniscal repair compared with younger patients.
UNASSIGNED: To establish the clinical performance of meniscal repair in \"older\" patients (age, ≥40 years) and compare it with performance in \"younger\" patients (age, <40 years).
UNASSIGNED: Systematic review; Level of evidence, 4.
UNASSIGNED: A systematic literature review was performed in September 2021 using Embase and PubMed to identify published English-language studies that reported on a meniscal repair in >5 patients aged ≥40 years. Outcomes of interest were success/failure rate (as defined by the study), revision meniscal procedure rate, and patient-reported outcomes. Meta-analyses were used to synthesize outcomes across all studies in older patients. Meta-analyses were also used to compare outcomes between older and younger patients across studies, providing data on both age groups.
UNASSIGNED: Fourteen studies were identified. Meniscal repair in older patients was determined to have a failure rate of 12% (95% CI, 7.3% to 19.4%) and a revision meniscal procedure rate of 9.8% (95% CI, 6.2% to 15.0%). The postoperative Lysholm score was 86.7 (95% CI, 81.7 to 91.7). No statistically significant differences were observed between older and younger patients in failure rate (relative risk [RR], 0.73 [95% CI, 0.44 to 1.21]; P = .2205), revision meniscal procedure rate (RR, 0.69 [95% CI, 0.41 to 1.16]; P = .1613), or Lysholm scores (mean difference, 2.3 [95% CI, -4.7 to 9.2]; P = .5278, 4 studies).
UNASSIGNED: Meniscal repair in selected patients aged ≥40 years resulted in good success rates and patient-reported outcome measures, which appear similar to those reported for patients aged <40 years. Therefore, meniscal repairs can be performed in at least a specific portion of \"older\" patients, and age per se should not be the sole determining factor in whether to perform a meniscal repair.

UNASSIGNED: To describe the anatomical and histological characteristics of the human MTL (meniscotibial ligament) that keeps the meniscus stable and are rarely discussed.
UNASSIGNED: Descriptive laboratory study.
UNASSIGNED: In total, six fresh-frozen adult cadaver knees were dissected, and the dissection protocol were designed by two experienced anatomy professors. The anatomical morphology of MTL was observed. The main anatomical specimens included meniscus, tibial plateau, MTL. The osteotome was used to excise the portion of the tibial plateau, which could obtain the complex including partial meniscus, MTL, and a tibial fragment. A histopathologic study was performed by two experienced pathologists.
UNASSIGNED: Macroscopically, the MTL could be divided into two parts: medial meniscotibial ligament (MMTL)and lateral meniscotibial ligament (LMTL). The MMTL is distributed continuously, whereas the LMTL is discontinuous on the tibial plateau. The average length from the tibial attachment of the LMTL to the articular surface was 19 ± 1.0mm (mean ± SD). The average length from the tibial attachment of the MMTL to the articular surface was 10 ± 1.2 mm (mean ± SD). Microscopy of the MTL showed that the MTL is a ligamentous tissue, composed of a network of oriented collagenous fibers.
UNASSIGNED: In all knees, the MTL was inserted on the outer edge of the meniscus, attaching to the tibia below the level of articular cartilage, which was key to maintaining the rotational stability of knee and the meniscus in the physiological position on the tibial plateau. Histological analysis of this ligament demonstrated that the MTL is a veritable ligamentous structure, which is made up of collagen type I-expressing fibroblasts.
UNASSIGNED: This article contributes to the understanding of the anatomical and histological characteristics of the MTL. It is beneficial to promote the development of relevant surgical techniques for the MTL lesion.

BACKGROUND: This study investigates the potential of novel meniscal parameters as predictive factors for incident radiographic knee osteoarthritis (ROA) over a span of four years, as part of the Osteoarthritis Initiative (OAI) study.
OBJECTIVE: Quantitative measurements of meniscal parameters alteration could serve as predictors of OA\'s occurrence and progression.
METHODS: A nested matched case-control study design was used to select participants from OAI study. Case knees (n = 178) were defined as those with incident ROA (Kellgren Lawrence Grade (KLG) 0 or 1 at baseline (BL), evolving into KLG 2 or above by year 4). Control knees were matched one-to-one by sex, age and radiographic status with case knees. The mean distance from medial-to-lateral meniscal lesions [Mean(MLD)], mean value of tibial plateau width [Mean(TPW)] and the mean of the relative percentage of the medial-to-lateral meniscal lesions distance [Mean(RMLD)] were evaluated through coronal T2-weighted turbo spin echo (TSE) MRI at P-0 (visit when incident ROA was found on radiograph), P-1(one year prior to P-0) and baseline, respectively. Using the imaging data of one patient, the mechanism was investigated by finite element analysis.
RESULTS: Participants were on average 60.22 years old, predominantly female (66.7%) and overweight (mean BMI: 28.15). Mean(MLD) and Mean(RMLD) were significantly greater for incident knees compared to no incident knees at baseline, P-1 and P-0. [Mean(MLD), Mean(RMLD); (42.56-49.73) mean ± (7.70-9.52) mm SD vs. (38.14-40.78) mean ± (5.51-7.05)mm SD; (58.61-68.95) mean ± (8.52-11.40) mm SD vs. (52.52-56.35) mean ± (6.53-7.85)mm SD, respectively]. Baseline Mean(MLD) and Mean(RMLD), [Adjusted OR, 95%CI: 1.11(1.07 to 1.16) and 1.13(1.09 to 1.17), respectively], were associated with incident ROA during 4 years, However, Mean(TPW) [Adjusted OR, 95%CI: 0.98(0.94 to 1.02)] was not associated with incident ROA during 4 years. While Mean(TPW) at P-1 and P-0 was not associated with the risk of incident ROA, Mean(MLD) and Mean(RMLD) at P-1 and P-0 were significantly positively associated with the risk of incident ROA.
CONCLUSIONS: The meniscal parameters alteration could be an important imaging biomarker to predict the occurrence of ROA.

Meniscus injuries pose significant challenges in clinical settings, primarily due to the intrinsic heterogeneity of the tissue and the limited efficacy of current treatments. Endogenous cell migration is crucial for the healing process, yet the regulatory mechanisms of meniscus cell migration and its zonal dependency within the meniscus are not fully understood. Thus, this study investigates the role of epigenetic mechanisms in governing meniscus cell migration under inflammatory conditions, with a focus on their implications for injury healing and regeneration. Here, we discovered that a proinflammatory cytokine, TNF-α treatment significantly impedes the migration speed of inner meniscus cells, while outer meniscus cells are unaffected, underscoring a zonal-dependent response within the meniscus. Our analysis identified distinct histone modification patterns and chromatin dynamics between inner and outer meniscus cells during migration, highlighting the necessity to consider these zonal-dependent properties in devising repair strategies. Specifically, we found that TNF-α differentially influences histone modifications, particularly H3K27me3, between the two cell types. Transcriptome analysis further revealed that TNF-α treatment induces substantial gene expression changes, with inner meniscus cells exhibiting more pronounced alterations than outer cells. Gene cluster analysis pointed to distinct responses in chromatin remodeling, extracellular matrix assembly, and wound healing processes between the zonal cell populations. Moreover, we identified potential therapeutic targets by employing existing epigenetic drugs, GSKJ4 (a histone demethylase inhibitor) and C646 (a histone acetyltransferase inhibitor), to successfully restore the migration speed of inner meniscus cells under inflammatory conditions. This highlights their potential utility in treating meniscus tear injuries. Overall, our findings elucidate the intricate interplay between epigenetic mechanisms and meniscus cell migration, along with its meniscus zonal dependency. This study provides insights into potential targets for enhancing meniscus repair and regeneration, which may lead to improved clinical outcomes for patients with meniscus injuries and osteoarthritis.

UNASSIGNED: Knee osteoarthritis is a common, degenerative joint disease that causes chronic pain that affects daily life. Our study aims to evaluate geriatric patients aged 65 and over with knee pain in terms of osteoarthritis with radiography and magnetic resonance imaging and to investigate its relationship with meniscal pathologies.
UNASSIGNED: Radiography and magnetic resonance imaging of patients aged 65-88 years with knee pain were evaluated in terms of knee osteoarthritis and staging was performed. Meniscal pathologies were evaluated in magnetic resonance imaging, and the prevalence of different meniscal lesion types was calculated. In addition, the relationship between knee osteoarthritis and meniscal pathologies was analyzed.
UNASSIGNED: Radiographic evidence of knee osteoarthritis was found in 182 (84.2%) of the 216 cases in our study group. A strong correlation was found between the degrees of knee osteoarthritis on magnetic resonance imaging and radiography. At least one meniscus pathology was observed in all 182 radiography cases with knee osteoarthritis findings. At least one meniscus pathology was observed in 29 (85.3%) of those without osteoarthritis signs. It was determined that meniscus degeneration, tear, and extrusion were observed more frequently in patients with knee osteoarthritis than in patients without osteoarthritis. Meniscal extrusion and complex and horizontaltype tears were the most common lesions.
UNASSIGNED: Osteoarthritis was found to be common in geriatric patients with knee pain. A correlation was found between radiography and magnetic resonance imaging regarding knee osteoarthritis. It was observed that meniscal pathologies were detected more frequently in patients with knee osteoarthritis.

UNASSIGNED: Meniscal root tears are defined as soft-tissue and/or osseous injuries that rip or avulse within one centimeter of the meniscal insertion to the tibial plateau. These injuries impact around 100,000 patients a year and make up 10 % to 21 % of all meniscal tears. Meniscal extrusion frequently happens when there are root rips, and the transmission of circumferential hoop loads is hampered.
METHODS: We present one case of a 28-year-old male who complained of pain and stiffness in his left knee since 2 years after undergoing ACL reconstruction using a hamstring autograft. His examination revealed joint line tenderness on both the medial and lateral sides of the left knee. Further investigations involving X-ray and MRI established the diagnosis of both medial and lateral meniscal root tears, which were surgically managed using the transtibial pullout technique.
CONCLUSIONS: The biomechanical implications of meniscal root tears, such as loss of hoop forces and increased tibiofemoral contact pressures, underscore the importance of timely diagnosis and management. The literature advocates surgical treatment for managing root tears, as leaving them without surgical intervention can lead to functional outcomes similar to those of total meniscectomy.
CONCLUSIONS: This case report presents both menisci posterior root tears with an intact ACL graft which is unique in that they commonly tear in conjuction with ACL. These kind of injuries necessitates prompt diagnosis and surgical intervention to protect the knee from early arthritic changes.

BACKGROUND: Meniscal sparing surgery is a widely utilised treatment option for unstable meniscal tears with the aim of minimising the risk of progression towards osteoarthritis. However, there is limited data in the literature on meniscal repair outcomes in skeletally immature patients.
OBJECTIVE: To evaluate the re-operation rate and functional outcomes of meniscal repairs in children and adolescents.
METHODS: We performed a retrospective review of all patients who underwent arthroscopic meniscal repair surgery between January 2007 and January 2018. All patients were under the age of 18 at the time of surgery. Procedures were all performed by a single surgeon. Information was gathered from our hospital Electronic Patient Records system. The primary outcome measure was re-operation rate (need for further surgery on the same meniscus). Secondary outcome measures were surgical complications and patient reported outcome measures that were International Knee Documentation Committee (IKDC), Tegner and Lysholm scores.
RESULTS: We identified 59 patients who underwent 66 All-inside meniscal repairs (32 medial meniscus and 34 Lateral meniscus). Meniscal repairs were performed utilizing FasT-Fix (Smith and Nephew) implants. There were 37 males and 22 females with an average age of 14 years (range 6-16). The average follow-up time was 53 months (range 26-140). Six patients had concomitant anterior cruciate ligament reconstruction surgery along with the meniscal repair. There were no intra-operative complications. The re-operation rate for meniscal repairs was 16.6% (11 cases) with 2 patients requiring further meniscal repairs and 9 patients underwent partial meniscectomies. The mean postoperative IKDC score was 88 (44-100), Tegner score was 7(2-10) and Lysholm score was 94 (57-100).
CONCLUSIONS: Our results showed that arthroscopic repair of meniscal tears in the paediatric population is an effective treatment option that has a low failure rate and good postoperative clinical with the advantage of preserving meniscal tissues.

Investigate meniscal extracellular matrix degradation. Equine menisci (n = 34 from 17 horses) were studied. Site-matched sections were cut and scored from three regions (ROIs; n = 102) and stained for histology, proteoglycan (safranin O and fast green), aggrecan, and collagen cleavage (NITEGE, DIPEN, and C1,2C antibodies, respectively). Picrosirius red and second harmonic generation microscopy were performed to investigate collagen ultrastructure. A total of 42 ROIs met the inclusion criteria and were included in the final analysis. The median (range) ROI histological score was 3 (0-9), providing a large spectrum of pathology. The median (range) proteoglycan score was 1 (0-3), representing superficial and central meniscal loss. The median (range) of DIPEN, NITEGE, and C1,2C scores was 1 (0-3), revealing immunostaining of the femoral and tibial surfaces. The proteoglycan scores exhibited significant positive associations with both histologic evaluation (p = 0.03) and DIPEN scores (p = 0.02). Additionally, a robust positive association (p = 0.007) was observed between the two aggrecanolysis indicators, NITEGE and DIPEN scores. A negative association (p = 0.008) was identified between NITEGE and histological scores. The C1,2C scores were not associated with any other scores. Picrosirius red and second harmonic generation microscopy (SHGM) illustrated the loss of the collagen matrix and structure centrally. Proteoglycan and collagen degradation commonly occur superficially in menisci and less frequently centrally. The identification of central meniscal proteoglycan and collagen degradation provides novel insight into central meniscal degeneration. However, further research is needed to elucidate the etiology and sequence of degradative events.

UNASSIGNED: To investigate the construction of a novel tissue engineered meniscus scaffold based on low temperature deposition three-dimenisonal (3D) printing technology and evaluate its biocompatibility.
UNASSIGNED: The fresh pig meniscus was decellularized by improved physicochemical method to obtain decellularized meniscus matrix homogenate. Gross observation, HE staining, and DAPI staining were used to observe the decellularization effect. Toluidine blue staining, safranin O staining, and sirius red staining were used to evaluate the retention of mucopolysaccharide and collagen. Then, the decellularized meniscus matrix bioink was prepared, and the new tissue engineered meniscus scaffold was prepared by low temperature deposition 3D printing technology. Scanning electron microscopy was used to observe the microstructure. After co-culture with adipose-derived stem cells, the cell compatibility of the scaffolds was observed by cell counting kit 8 (CCK-8), and the cell activity and morphology were observed by dead/live cell staining and cytoskeleton staining. The inflammatory cell infiltration and degradation of the scaffolds were evaluated by subcutaneous experiment in rats.
UNASSIGNED: The decellularized meniscus matrix homogenate appeared as a transparent gel. DAPI and histological staining showed that the immunogenic nucleic acids were effectively removed and the active components of mucopolysaccharide and collagen were remained. The new tissue engineered meniscus scaffolds was constructed by low temperature deposition 3D printing technology and it had macroporous-microporous microstructures under scanning electron microscopy. CCK-8 test showed that the scaffolds had good cell compatibility. Dead/live cell staining showed that the scaffold could effectively maintain cell viability (>90%). Cytoskeleton staining showed that the scaffolds were benefit for cell adhesion and spreading. After 1 week of subcutaneous implantation of the scaffolds in rats, there was a mild inflammatory response, but no significant inflammatory response was observed after 3 weeks, and the scaffolds gradually degraded.
UNASSIGNED: The novel tissue engineered meniscus scaffold constructed by low temperature deposition 3D printing technology has a graded macroporous-microporous microstructure and good cytocompatibility, which is conducive to cell adhesion and growth, laying the foundation for the in vivo research of tissue engineered meniscus scaffolds in the next step.
UNASSIGNED: 基于低温沉积3D打印技术构建新型组织工程半月板支架，评价该支架理化性质及生物相容性。.
UNASSIGNED: 取新鲜猪膝关节半月板，采用改良物理化学联合方法脱细胞处理，获得脱细胞半月板基质匀浆；经大体观察、HE及DAPI染色观察脱细胞效果，甲苯胺蓝、番红O及天狼猩红染色评估黏多糖和胶原保留情况。然后制备脱细胞半月板基质生物墨水，通过低温沉积3D打印技术制备新型组织工程半月板支架。扫描电镜观察微观结构；与脂肪来源干细胞共培养后，采用细胞计数试剂盒8（cell counting kit 8，CCK-8）检测支架细胞相容性，死/活细胞染色和细胞骨架染色观察细胞活性和形态；植入大鼠皮下后组织学染色评估支架炎症细胞浸润与降解情况。.
UNASSIGNED: 脱细胞处理后半月板基质匀浆呈透明凝胶状，DAPI和组织学染色示免疫原性的核酸去除，同时黏多糖及胶原成分保留。采用低温沉积3D打印技术成功构建新型组织工程半月板支架，扫描电镜示支架呈分级大孔-微孔的微观结构；CCK-8检测示支架具有良好细胞相容性；死/活细胞染色示支架可有效维持细胞活性（>90%）；细胞骨架染色示支架有利于细胞黏附和铺展；支架植入大鼠皮下1周后有轻度炎症反应，3周后未见明显炎症反应，并可见支架逐步降解。.
UNASSIGNED: 基于低温沉积3D打印技术构建的新型组织工程半月板支架具有分级大孔-微孔的微观结构和良好细胞相容性，有利于细胞黏附和生长，为下一步体内研究奠定基础。.