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Connective Tissue Research 2020Knee meniscus is a wedge-shaped fibrocartilaginous tissue, playing important roles in maintaining joint stability and function. Injuries to the meniscus, particularly... (Review)
Review
Knee meniscus is a wedge-shaped fibrocartilaginous tissue, playing important roles in maintaining joint stability and function. Injuries to the meniscus, particularly with the avascular inner third zone, hardly heal and frequently progress into structural breakdown, followed by the initiation of osteoarthritis. As the importance of meniscus in joint function and diseases is being recognized, the field of meniscus research is growing. Not only development, biology, and metabolism but also injury, repair, and healing of meniscus are being actively investigated. As meniscus functions as an integrated unit of a knee joint, in vivo models with various species have been the predominant method for studying meniscus pathophysiology and for testing healing/regeneration strategies. However, in vivo models for meniscus studies suffer from low reproducibility and high cost. To complement the limitations of in vivo animal models, several types of meniscus explants have been applied as highly controlled, standardized in vitro models to investigate meniscus metabolism, pathophysiology, and repair or regeneration process. This review summarizes and compares the existing meniscus explant models. We also discuss the advantages and disadvantages of each explant model. Despite few outstanding challenges, meniscus explant models have potential to serve as an effective tool for investigations of meniscus metabolism, injury, repair and healing.
Topics: Animals; Humans; Knee Injuries; Menisci, Tibial; Models, Biological; Regeneration; Tissue Culture Techniques; Tissue Engineering
PubMed: 31842590
DOI: 10.1080/03008207.2019.1702031 -
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 -
Orthopaedics & Traumatology, Surgery &... Feb 2021The menisci play a key role in knee biomechanics and long-term cartilage protection. Preserving the meniscus is thus a major functional consideration in children and... (Review)
Review
The menisci play a key role in knee biomechanics and long-term cartilage protection. Preserving the meniscus is thus a major functional consideration in children and adolescents. In normal menisci, lesions are traumatic in origin. They are often vertical, in the posterior segment, associated with anterior cruciate ligament tear. In abnormal menisci, lesions are much more specific to children, occurring atraumatically, mainly in discoid menisci. Clinical signs of traumatic meniscal lesion are minimal, and associated ligament involvement should be systematically screened for. In contrast, clinical findings are rich and specific in discoid malformative pathology, sometimes showing the typical "clunk" sign highly suggestive of a detachment. The complementary examination of choice is MRI. In children more than in adults, lesions need screening for in apparently normal menisci. This particularly concerns ramp lesions of the medial meniscus. It is important also to be aware of false signs, and notably linear hypersignal of vascular origin in the posterior segment of the medial meniscus. MRI is essential in determining type of tear and guiding surgery in discoid meniscal pathology. Indications for meniscal repair in children are maximal, even in lesions extending into the white zone, and the risk of failure needs to be assumed. All meniscal suture techniques - all-inside, in-out and out-in - need to be acquired. Meniscectomy, even partial, should be exceptional. Treatment of symptomatic discoid meniscus usually involves minimal central meniscoplasty and suture of the discovered lesion. Results of meniscal repair in children are generally very satisfactory, whatever the type or site of lesion. Vertical suture is to be preferred; suture failure is often only partial. In all, optimal treatment of meniscal pathology in children and adolescents requires perfect knowledge of pediatric specificities and above all mastery of repair techniques to restore meniscal tissue as fully as possible so as to conserve future knee function.
Topics: Adolescent; Adult; Anterior Cruciate Ligament Injuries; Arthroscopy; Cartilage Diseases; Child; Humans; Meniscectomy; Menisci, Tibial
PubMed: 33321242
DOI: 10.1016/j.otsr.2020.102775 -
BioMed Research International 2018The incidence and extent of graft extrusion after meniscus allograft transplantation (MAT) may differ in patients undergoing medial and lateral meniscus transplantation... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The incidence and extent of graft extrusion after meniscus allograft transplantation (MAT) may differ in patients undergoing medial and lateral meniscus transplantation due to the use of different surgical techniques. This meta-analysis was therefore designed to quantify the extent and incidence of graft extrusion after meniscus allograft transplantation.
METHODS
Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, all studies reporting absolute extrusion, relative percentage of extrusion (RPE), or frequency of major extrusions (>3 mm) on magnetic resonance imaging in patients undergoing medial or lateral MAT were included.
RESULTS
The pooled mean absolute extrusion following all MATs was 3.15 mm but was significantly greater following medial than lateral MAT (3.26 versus 3.01 mm; = 0.001). The pooled mean RPE following all MATs was 32.79% and was significantly greater after medial than lateral MAT (32.69% versus 28.81%; < 0.001). The pooled mean proportion of knees with major (>3 mm) extrusion was 53% (95% CI: 49% to 58%) and was significantly greater after medial than lateral MAT (61% versus 39%; < 0.001).
CONCLUSION
Mean graft extrusion after arthroscopic assisted MAT using bony fixation was 3.2 mm, with major graft extrusion > 3 mm occurring in about 50% of transplanted menisci. Graft extrusion was significantly greater after medial than lateral MAT.
Topics: Humans; Incidence; Knee; Knee Joint; Menisci, Tibial; Meniscus; Orthopedic Procedures; Transplantation, Homologous
PubMed: 29770332
DOI: 10.1155/2018/5251910 -
Acta Bio-medica : Atenei Parmensis Jan 2018The popliteomeniscal fascicules (PMFs) provide the attachment of the lateral meniscus to the popliteus musculotendinous region, forming the floor and the roof the... (Review)
Review
The popliteomeniscal fascicules (PMFs) provide the attachment of the lateral meniscus to the popliteus musculotendinous region, forming the floor and the roof the popliteal hiatus. In the second half of 1900's, some anatomic studies claim the important function of the PMF as stabilizers of the lateral meniscus; these anatomical structures work in conjunction with the popliteus musculotendinous unit to prevent excessive lateral meniscal movement and possible meniscus subluxation. A correct diagnosis of the PMFs pathology is crucial to establish the suitable surgical treatment for each patient. MRI is a well-established imaging technique in the musculoskeletal system and the frequency of recognition of normal PMF in the normal knees is high in almost all MRI studies. At day, the gold standard for diagnosis is the arthroscopic evaluation that allows the direct visualization of the popliteo-meniscal ligaments at popliteal hiatus and evaluation of lateral meniscal movements. For this reason if unstable condition of meniscus was suspected, arthroscopic observation with probing into the popliteo-meniscal fascicle area is essential for the identification of the fascicle tears. Despite many treatments have being proposed in literature since now there is high recurrence of knee locking after repair and it is fundamental to develop new surgical techniques in order to achieve better outcome.
Topics: Arthroscopy; Humans; Knee Injuries; Knee Joint; Magnetic Resonance Imaging; Menisci, Tibial; Muscle, Skeletal; Tendon Injuries; Tendons; Tibial Meniscus Injuries
PubMed: 29350634
DOI: 10.23750/abm.v89i1-S.7007 -
Connective Tissue Research Sep 2016The discoid lateral meniscus (DLM) is an anatomically abnormal meniscus that covers a greater area of the tibial plateau than the normal meniscus. The DLM is classified... (Comparative Study)
Comparative Study
The discoid lateral meniscus (DLM) is an anatomically abnormal meniscus that covers a greater area of the tibial plateau than the normal meniscus. The DLM is classified into two types: complete (CDLM) and incomplete (ICDLM) types. In this study, we investigated the histological and cell biological characteristics of CDLM and ICDLM. The number of blood vessels, proteoglycan deposition, and collagen distribution were assessed using meniscal tissues. Collagen production was also investigated in CDLM and ICDLM cells. The intercondylar region of the CDLM had a higher number of blood vessels than the inner region of the ICDLM. Safranin O staining density and type II collagen deposition in ICDLM were higher than those in CDLM. Type II collagen-positive cells were higher in ICLDM than in CDLM. CDLM cells showed slender fibroblastic morphology, while ICDLM cells were triangular chondrocytic in shape. This study demonstrated that the intercondylar region of the CDLM showed similar properties to the outer region of the meniscus. The inner region of the ICDLM, on the other hand, differed from the intercondylar region of the CDLM. Our results suggest that the intercondylar region of the CDLM may have a high healing potential like the outer meniscus.
Topics: Adolescent; Adult; Cell Proliferation; Cell Shape; Child; Chondrocytes; Collagen Type II; Demography; Fibroblasts; Humans; Menisci, Tibial; Neovascularization, Physiologic; Proteoglycans; Staining and Labeling; Young Adult
PubMed: 27267748
DOI: 10.1080/03008207.2016.1195827 -
The Knee Aug 2022This study aimed to explore the changes in lower limb axial alignment and knee joint function after arthroscopic partial resection of the discoid lateral meniscus. (Review)
Review
AIM
This study aimed to explore the changes in lower limb axial alignment and knee joint function after arthroscopic partial resection of the discoid lateral meniscus.
METHODS
Preoperative and postoperative full-length weight-bearing radiographs of the lower limb were obtained from a total of 161 patients with lateral menisci tears from September 2018 to September 2020 who underwent partial meniscal resection. The patients were divided into discoid meniscus group (DMG) and ordinary meniscus group (OMG). The measured mechanical axis deviation (MAD), proximal tibia angle (PTA), and distal femoral angle (DFA) in the axial alignment of the lower limb were determined before and after surgery. Knee joint function on the affected side was determined using the International Knee Documentation Committee (IKDC) subjective scale and the Lysholm knee scoring scale before surgery and at one, six, 12, and 24 months after surgery.
RESULTS
For MAD and DFA, there were statistically significant differences between the preoperative and postoperative findings within each group (P < 0.01); the MAD and DFA were smaller after surgery. The difference in preoperative and postoperative PTA of the DMG was statistically significant (P < 0.01), meaning that the PTA becomes larger after surgery. The differences in preoperative and postoperative PTA of the OMG, preoperative PTA between the two groups, and postoperative PTA between the two groups were not statistically significant (P > 0.05). Intragroup comparisons of the IKDC subjective scale and the Lysholm knee scoring scale before and after surgery revealed significant differences (P < 0.05).
CONCLUSION
Arthroscopic partial resection of the discoid lateral meniscus is a safe and effective surgical method that can significantly improve knee joint function. Although the axial arrangement of the lower limbs will be slightly changed in the early stage, it will still be within the normal range after surgery in patients with normal lower limb axial alignment. For patients with varus or valgus before surgery, this procedure should be applied with caution.
Topics: Arthroscopy; Humans; Knee Joint; Lower Extremity; Menisci, Tibial; Meniscus; Retrospective Studies; Tibial Meniscus Injuries
PubMed: 35809449
DOI: 10.1016/j.knee.2022.06.010 -
Journal of Healthcare Engineering 2021The aim of the present study is to build a software implementation of a previous study and to diagnose discoid lateral menisci on knee joint radiograph images. A total...
The aim of the present study is to build a software implementation of a previous study and to diagnose discoid lateral menisci on knee joint radiograph images. A total of 160 images from normal individuals and patients who were diagnosed with discoid lateral menisci were included. Our software implementation includes two parts: preprocessing and measurement. In the first phase, the whole radiograph image was analyzed to obtain basic information about the patient. Machine learning was used to segment the knee joint from the original radiograph image. Image enhancement and denoising tools were used to strengthen the image and remove noise. In the second phase, edge detection was used to quantify important features in the image. A specific algorithm was designed to build a model of the knee joint and measure the parameters. Of the test images, 99.65% were segmented correctly. Furthermore, 97.5% of the tested images were segmented correctly and their parameters were measured successfully. There was no significant difference between manual and automatic measurements in the discoid (=0.28) and control groups (=0.15). The mean and standard deviations of the ratio of lateral joint space distance to the height of the lateral tibial spine were compared with the results of manual measurement. The software performed well on raw radiographs, showing a satisfying success rate and robustness. Thus, it is possible to diagnose discoid lateral menisci on radiographs with the help of radiograph-image-analyzing software (BM3D, etc.) and artificial intelligence-related tools (YOLOv3). The results of this study can help build a joint database that contains data from patients and thus can play a role in the diagnosis of discoid lateral menisci and other knee joint diseases in the future.
Topics: Artificial Intelligence; Humans; Knee Joint; Machine Learning; Menisci, Tibial; Osteoarthritis, Knee; Retrospective Studies
PubMed: 33968355
DOI: 10.1155/2021/6662664 -
Journal of Orthopaedic Surgery (Hong... 2023Complete meniscus root tear is associated with meniscus extrusion; this causes a loss of meniscus function and accelerated osteoarthritis of the knee. Existing... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Complete meniscus root tear is associated with meniscus extrusion; this causes a loss of meniscus function and accelerated osteoarthritis of the knee. Existing small-scale retrospective case-control studies suggested that the outcomes were different between medial and lateral meniscus root repair. This meta-analysis aims to study whether such discrepancies exist via a systematic review of the available evidence in the literature.
METHODS
Studies evaluating the outcomes of surgical repair of posterior meniscus root tears, with reassessment MRI or second-look arthroscopy, were identified through a systematic search of PubMed, Embase, and Cochrane Library. The degree of meniscus extrusion, healing status of the repaired meniscus root, and functional outcome scores after repair were the outcomes of interest.
RESULTS
Among the 732 studies identified, 20 studies were included in this systematic review. 624 knees and 122 knees underwent MMPRT and LMPRT repair, respectively. The amount of meniscus extrusion following MMPRT repair was 3.8 ± 1.7 mm, which was significantly larger than the 0.9 ± 1.2 mm observed after LMPRT repair ( < 0.001). Significantly better healing outcomes were observed on reassessment MRI after LMPRT repair ( < 0.001). The postoperative Lysholm score and IKDC score was also significantly better after LMPRT than MMPRT repair ( < 0.001).
CONCLUSIONS
LMPRT repairs resulted in significantly less meniscus extrusion, substantially better healing outcomes on MRI, and superior Lysholm/IKDC scores, when compared to MMPRT repair. This is the first meta-analysis we are aware of that systematically reviews the differences in the clinical, radiographic, and arthroscopic results of MMPRT and LMPRT repair.
Topics: Humans; Menisci, Tibial; Retrospective Studies; Knee Joint; Osteoarthritis; Magnetic Resonance Imaging; Arthroscopy; Rupture
PubMed: 37173149
DOI: 10.1177/10225536231175233 -
PloS One 2015The meniscus root plays an essential role in maintaining the circumferential hoop tension and preventing meniscal displacement. Studies on meniscus root tears have...
The meniscus root plays an essential role in maintaining the circumferential hoop tension and preventing meniscal displacement. Studies on meniscus root tears have investigated the relationship of osteoarthritis and an anterior cruciate ligament tear. However, few studies have directly compared the medial and lateral root tears. To assess the prevalence of meniscal extrusion and its relationship with clinical features in medial and lateral meniscus root tears, we performed a retrospective review of the magnetic resonance imaging (MRI) results of 42 knee patients who had meniscus posterior horn root tears and who had undergone arthroscopic operations. The presence of meniscal extrusion was evaluated and the exact extent was measured from the tibial margin. The results were correlated with arthroscopic findings. Clinical features including patients' ages, joint abnormalities, and previous trauma histories were evaluated. Twenty-two patients had medial meniscus root tears (MMRTs) and twenty patients had lateral meniscus root tears (LMRTs). Meniscal extrusion was present in 18 MMRT patients and one LMRT patient. The mean extent of extrusion was 4.2mm (range, 0.6 to 7.8) in the MMRT group and 0.9mm (range, -1.9 to 3.4) in the LMRT group. Five patients with MMRT had a history of trauma, while 19 patients with LMRT had a history of trauma. Three patients with MMRT had anterior cruciate ligament (ACL) tears, while 19 patients with LMRT had ACL tears. The mean age of the patients was 52 years (range: 29-71 years) and 30 years (range: 14-62 years) in the MMRT and LMRT group, respectively. There was a significant correlation between a MMRT and meniscal extrusion (p<0.0001), and between an ACL tear and LMRT (p<0.0001). A history of trauma was significantly common in LMRT (p<0.0001). LMRT patients were significantly younger than MMRT patients (p<0.0001). Kellgren-Lawrence (K-L) grade differed significantly between MMRT and LMRT group (p<0.0001). Meniscal extrusion is common in patients with MMRTs. However, it is rare in patients with LMRTs, which are more commonly associated with a history of trauma and ACL tears.
Topics: Adolescent; Adult; Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Arthroscopy; Female; Humans; Knee Injuries; Knee Joint; Magnetic Resonance Imaging; Male; Menisci, Tibial; Middle Aged; Retrospective Studies; Tibial Meniscus Injuries; Young Adult
PubMed: 26488288
DOI: 10.1371/journal.pone.0141021