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Journal of the Mechanical Behavior of... Mar 2022The knee menisci are prone to mechanical fatigue injury from the cyclic tensile stresses that are generated during daily joint loading. Here we characterize the tensile...
The knee menisci are prone to mechanical fatigue injury from the cyclic tensile stresses that are generated during daily joint loading. Here we characterize the tensile fatigue behavior of human medial meniscus and investigate the effect of aging on fatigue strength. Test specimens were excised from the medial meniscus of young (under 40 years) and older (over 65 years) fresh-frozen cadaver knees. Cyclic uniaxial tensile loads were applied parallel to the primary circumferential fibers at 70%, 50%, 40%, or 30% of the predicted ultimate tensile strength (UTS) until failure occurred or one million cycles was reached. Equations for fatigue strength (S-N curve) and the probability of fatigue failure (unreliability curves) were created from the measured number of cycles to failure. The mean number of cycles to failure at 70%, 50%, 40%, and 30% of UTS were estimated to be approximately 500, 40000, 340000, and 3 million cycles, respectively. The endurance limit, defined as the tensile stress that can be safely applied for the average lifetime of use (250 million cycles), was estimated to be 10% of UTS (∼1.0 MPa). When cyclic tensile stresses exceeded 30% of UTS (∼3.0 MPa), the probability of fatigue failure rapidly increased. While older menisci were generally weaker and more susceptible to fatigue failures at high-magnitude tensile stresses, both young and older age groups had similar fatigue resistance at low-magnitude tensile stresses. In addition, we found that fatigue failures occurred after the dynamic modulus decreased during cyclic loading by approximately 20%. This experimental study has quantified fundamental fatigue properties that are essential to properly predict and prevent injury in meniscus and other soft fibrous tissues.
Topics: Aged; Humans; Knee Joint; Menisci, Tibial; Meniscus; Stress, Mechanical; Tensile Strength
PubMed: 35091175
DOI: 10.1016/j.jmbbm.2021.105057 -
BMC Musculoskeletal Disorders Nov 2023Discoid meniscus (DM) and femoral trochlear dysplasia (FTD) are common knee disorders. Both as congenital malformation, whether there is a connection between them is...
BACKGROUND
Discoid meniscus (DM) and femoral trochlear dysplasia (FTD) are common knee disorders. Both as congenital malformation, whether there is a connection between them is unclear and the research on their prevalence in the general population is inadequate. This study aimed to investigate the prevalence of FTD and DM in the general population through a large sample size, and to explore the relationship between them.
STUDY DESIGN
Retrospective study.
METHODS
Patients undergoing knee magnetic resonance imaging (MRI) examinations at our outpatient clinic were screened and 1003 patients were enrolled in DM group with 989 patients in non-DM (NDM) group. The type of DM and FTD was classified with Watanabe classification and Dejour's classification, respectively. The prevalence of FTD and DM in the general population and the relationship between them were evaluated.
RESULTS
The prevalence of DM and FTD was 10.0% and 14.5%, respectively. The overall percentage of FTD was higher in DM group (P < 0.001). The DM group has a higher percentage of all types of FTD except type D (P < 0.05), and a higher percentage of both low- and high-grade FTD (P < 0.001). There were 633 cases of type I DM and 370 cases of type II DM. The overall percentage of FTD was not significantly different between the two types (P = 0.106). No significant difference was detected for all types of FTD except type B (P < 0.05). The Type I DM group has a significant higher percentage of high-grade FTD than Type II group (P < 0.05).
CONCLUSION
Patients with a DM are more likely to have FTD regardless of the type of DM, while those with a type I DM are more prone to have a high grade FTD.
Topics: Humans; Retrospective Studies; Femur; Prevalence; Frontotemporal Dementia; Joint Instability; Knee Joint; Magnetic Resonance Imaging; Bone Diseases; Lower Extremity Deformities, Congenital; Meniscus; Menisci, Tibial
PubMed: 38037030
DOI: 10.1186/s12891-023-06958-x -
PloS One 2018Meniscal pathologies are among the most common injuries of the femorotibial joint in both human and equine patients. Pathological forces and ensuing injuries of the...
Meniscal pathologies are among the most common injuries of the femorotibial joint in both human and equine patients. Pathological forces and ensuing injuries of the cranial horn of the equine medial meniscus are considered analogous to those observed in the human posterior medial horn. Biomechanical properties of human menisci are site- and depth- specific. However, the influence of equine meniscus topography and composition on its biomechanical properties is yet unknown. A better understanding of equine meniscus composition and biomechanics could advance not only veterinary therapies for meniscus degeneration or injuries, but also further substantiate the horse as suitable translational animal model for (human) meniscus tissue engineering. Therefore, the aim of this study was to investigate the composition and structure of the equine knee meniscus in a site- and age-specific manner and their relationship with potential site-specific biomechanical properties. The meniscus architecture was investigated histologically. Biomechanical testing included evaluation of the shore hardness (SH), stiffness and energy loss of the menisci. The SH was found to be subjected to both age and site-specific changes, with an overall higher SH of the tibial meniscus surface and increase in SH with age. Stiffness and energy loss showed neither site nor age related significant differences. The macroscopic and histologic similarities between equine and human menisci described in this study, support continued research in this field.
Topics: Aging; Animals; Biomechanical Phenomena; Collagen; Compressive Strength; Female; Gait; Glycosaminoglycans; Hardness; Hardness Tests; Horses; Male; Meniscus; Stifle; Structure-Activity Relationship; X-Ray Microtomography
PubMed: 29522550
DOI: 10.1371/journal.pone.0194052 -
European Cells & Materials Aug 2019Meniscus regeneration is an unmet clinical need as damage to the meniscus is common and causes early osteoarthritis. The aim of the present study was to investigate the...
Meniscus regeneration is an unmet clinical need as damage to the meniscus is common and causes early osteoarthritis. The aim of the present study was to investigate the feasibility of a one-stage cell-based treatment for meniscus regeneration by augmenting a resorbable collagen-based implant with a combination of recycled meniscus cells and mesenchymal stromal cells (MSCs). Cell communication and fate of the different cell types over time in co-culture were evaluated by connexin 43 staining for gap junctions and polymerase chain reaction (PCR) to discriminate between meniscus cells and MSCs, based on a Y-chromosome gene. To define optimal ratios, human meniscus cells and bone-marrow-derived MSCs were cultured in different ratios in cell pellets and type I collagen hydrogels. In addition, cells were seeded on the implant in fibrin glue by static seeding or injection. Cellular communication by gap junctions was shown in co-culture and a decrease in the amount of MSCs over time was demonstrated by PCR. 20 : 80 and 10 : 90 ratios showed significantly highest glycosaminoglycan and collagen content in collagen hydrogels. The same statistical trend was found in pellet cultures. Significantly more cells were present in the injected implant and cell distribution was more homogenous as compared to the statically seeded implant. The study demonstrated the feasibility of a new one-stage cell-based procedure for meniscus regeneration, using 20 % meniscus cells and 80 % MSCs seeded statically on the implant. In addition, the stimulatory effect of MSCs towards meniscus cells was demonstrated by communication through gap junctions.
Topics: Aged; Cell Communication; Cells, Cultured; Coculture Techniques; Collagen; Connexin 43; Female; Gap Junctions; Glycosaminoglycans; Humans; Hydrogels; Male; Meniscus; Mesenchymal Stem Cells; Middle Aged; Regeneration; Stem Cell Transplantation; Tissue Scaffolds
PubMed: 31402442
DOI: 10.22203/eCM.v038a05 -
Osteoarthritis and Cartilage May 2016Obesity is the major risk factor for the development of osteoarthritis (OA); however, the mechanisms involved are not clearly understood. Obesity is associated with...
INTRODUCTION
Obesity is the major risk factor for the development of osteoarthritis (OA); however, the mechanisms involved are not clearly understood. Obesity is associated with increased production of adipokine and elevated levels of circulating free fatty acids (FFA). A recent study has shown that saturated fatty acid palmitate induced pro-inflammatory and pro-apoptotic pathways in chondrocytes. Meniscus has been shown to be more susceptible than articular cartilage to catabolic stimuli. Thus, the aim of this study was to determine the effect of FFA (specifically, palmitate) on meniscus cells.
METHODS
Cultured primary porcine meniscus cells were stimulated with 500 μM FFA (palmitate and oleate) for 24 h to induce endoplasmic reticulum (ER) stress. After treatment, cell lysates were prepared and immunoblotted for C/EBP homologous protein (CHOP). To determine the activation of unfolded protein response (UPR) signaling, cell lysates were probed for cJun n-terminal kinase (JNK), cleaved caspase -3 and Xbp-1s, an alternative mRNA splicing product generated due to Ire1α activation.
RESULTS
Treatment of isolated primary meniscus cells with palmitate but not oleate induced expression of CHOP and Xbp-1s. Palmitate treatment of meniscus cells also activated JNK and increased expression of caspase-3, thus promoting apoptosis in meniscus cells.
CONCLUSIONS
Palmitate induces ER stress and promotes apoptotic pathways in meniscus cells. This is the first study to establish ER stress as a key metabolic mechanistic link between obesity and OA, in addition to (or operating with) biomechanical factors.
Topics: Animals; Apoptosis; Cells, Cultured; Endoplasmic Reticulum Stress; Meniscus; Palmitates; Signal Transduction; Sus scrofa; Unfolded Protein Response
PubMed: 26687823
DOI: 10.1016/j.joca.2015.11.020 -
Orthopaedic Surgery Nov 2011Discoid lateral meniscus is an intra-articular knee disorder that typically presents in children and adolescents. The natural history depends on the type of anomaly and... (Review)
Review
Discoid lateral meniscus is an intra-articular knee disorder that typically presents in children and adolescents. The natural history depends on the type of anomaly and the nature and presence of symptoms. Management of this disorder should be directed toward resolution of the symptoms while preserving meniscal tissue and function. Modern surgical techniques make suturing and preservation of meniscal tissue feasible. In the present article, the clinical manifestations, diagnostic criteria and practical management considerations are reviewed.
Topics: Adolescent; Arthroscopy; Cartilage Diseases; Child; Child, Preschool; Female; Follow-Up Studies; Humans; Knee Joint; Magnetic Resonance Imaging; Male; Menisci, Tibial; Orthopedic Procedures; Pain Measurement; Severity of Illness Index; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 22021136
DOI: 10.1111/j.1757-7861.2011.00148.x -
Clinical and Translational Medicine Jan 2022Since the meniscus is an important stabilizing structure of the knee joint and has a significant role in load-bearing and shock absorption, so the complete structural...
Since the meniscus is an important stabilizing structure of the knee joint and has a significant role in load-bearing and shock absorption, so the complete structural and functional reconstructions of the teared menisci should be done not only after partial meniscectomy but also post total meniscectomy. So far, animal experiments and good clinical practice have showed that TMAT after total meniscectomy has partially solved the problem of structural and functional reconstructions after total meniscectomy. However, partial meniscectomy will also lead to accelerated knee degeneration, and its proportion is much higher than that of patients with total meniscectomy. Herein, the feasibility of PMAT after partial meniscectomy was investigated for the first time by using the 40% posterior horn meniscectomy model of the medial meniscus in Beagle dogs, and also for the first time, TMAT group and the total meniscectomy group were used as control groups. Compared with the TMAT, the transcriptomics evaluation, scanning electron microscope observation, histological regeneration and structure, biomechanical property, inflammation environment, and the knee function post PMAT were more similar to that of normal meniscus was first reported. This study provides a PMAT scheme with clinical translational value for the complete structural and functional reconstruction of the patients with partial meniscectomy and fills the gap in the field of teared meniscus therapy on the basis of quite well clinical applications of the meniscus repair and the TMAT.
Topics: Animals; Arthroplasty, Replacement, Knee; Dogs; Feasibility Studies; Meniscus; Transplantation, Homologous
PubMed: 35088938
DOI: 10.1002/ctm2.701 -
Connective Tissue Research 2017Meniscus injury and treatment occurred with the majority of anterior cruciate ligament reconstructions (ACLR) in the multicenter orthopedic outcomes (MOON) cohort. We... (Review)
Review
Meniscus injury and treatment occurred with the majority of anterior cruciate ligament reconstructions (ACLR) in the multicenter orthopedic outcomes (MOON) cohort. We describe the patient-reported outcomes, radiographic outcomes, and predictors of pain from meniscus injuries and treatment in the setting of ACLR. Patient-reported outcomes improve significantly following meniscus repair with ACLR, but differences exist based on the meniscus injury laterally (medial or lateral). Patients undergoing medial meniscus repair have worse patient-reported outcomes and more pain compared to those with uninjured menisci. However, lateral meniscal tears can be repaired with similar outcomes as uninjured menisci. Medial meniscal treatment (meniscectomy or repair) results in a significant loss of joint space at 2 years compared to uninjured menisci. Menisci treated with excision had a greater degree of joint space loss compared to those treated with repair. Clinically significant knee pain is more common following injuries to the medial meniscus and increased in patients who undergo early re-operation after initial ACLR. Future research efforts aimed at improving outcomes after combined ACLR and meniscus treatment should focus on optimizing biologic and mechanical environments that promote healing of medial meniscal tears sustained during ACL injury.
Topics: Adolescent; Anterior Cruciate Ligament Reconstruction; Female; Follow-Up Studies; Humans; Male; Meniscus; Pain, Postoperative; Treatment Outcome
PubMed: 28282214
DOI: 10.1080/03008207.2017.1297808 -
Journal of ISAKOS : Joint Disorders &... Feb 2022The prevalence of isolated meniscal injuries in children and adolescents is low; however, we see an increase mainly due to intensified sports-related activities at an... (Review)
Review
The prevalence of isolated meniscal injuries in children and adolescents is low; however, we see an increase mainly due to intensified sports-related activities at an early age. A meniscal repair should be attempted whenever possible as children present with increased meniscal healing potential. The diagnosis and management of meniscal tears involve both patient factors and tear characteristics: size, anatomical location and associated injuries. Special attention should be given to the feature of discoid menisci and related tears as they require a specific management plan. This state-of-the-art review highlights the most recent studies on clinical evaluation, surgical techniques, tips and tricks, pitfalls, outcomes, return-to-sports, geographical differences and future perspectives related to meniscal injuries in children and adolescents.
Topics: Adolescent; Arthroscopy; Cartilage Diseases; Child; Humans; Menisci, Tibial; Meniscus; Retrospective Studies; Tibial Meniscus Injuries
PubMed: 35543655
DOI: 10.1136/jisakos-2020-000496 -
Ugeskrift For Laeger Sep 2017The menisci play a major role in knee function regarding joint movement, stability, load distribution and load transmission. Injuries to the menisci cause pain, and... (Review)
Review
The menisci play a major role in knee function regarding joint movement, stability, load distribution and load transmission. Injuries to the menisci cause pain, and meniscal tears are a common reason for patient referral. In Denmark, partial meniscectomy increased significantly until 2010, and several studies have questioned the long-term effect of meniscectomy as an overall procedure. A Danish national clinical guideline on knee meniscal pathology was published in May 2016, and this article is a short summary of updated knowledge on meniscal pathology and relevant conclusions from the guideline.
Topics: Algorithms; Arthroscopy; Denmark; Humans; Meniscectomy; Menisci, Tibial; Osteoarthritis, Knee; Practice Guidelines as Topic; Range of Motion, Articular; Tibial Meniscus Injuries
PubMed: 28918786
DOI: No ID Found