Congenital absence of the lateral meniscus: A case report.

BACKGROUND: Congenital absence of the menisci is a rare anatomical variation characterized by the absence or underdevelopment of one or both menisci in the knee joint. The menisci are crucial in load distribution, joint stability, and shock absorption. Understanding the clinical presentation, diagnosis, and management of this condition is important for optimal patient care. CASE SUMMARY: A 27-year-old male with a long-standing history of knee pain underwent diagnostic arthroscopy, revealing a congenital absence of the meniscus. The patient's clinical findings, imaging results, surgical procedures, and pertinent images are detailed. This case presents a unique aspect with the congenital absence of the meniscus, contributing valuable insights to the literature on rare anatomical anomalies. CONCLUSION: This case of congenital absence of the menisci highlights the diagnostic challenges posed by rare anomalies. The diagnostic arthroscopy played a crucial role in identifying the absence of the meniscus and providing an explanation for the patient's persistent knee pain. The case underscores the importance of individualized treatment approaches, including physical therapy, for optimal management of rare meniscal anomalies. Further research is warranted to explore effective management strategies for the aforementioned cases and to expand our knowledge of these rare conditions.

Medial meniscus extrusion is associated with meniscus tears in US and MRI: A case control study.

OBJECTIVES: To study the medial meniscus extrusion (MME) in subjects with and without medial meniscal tears on magnetic resonance imaging (MRI), supine ultrasound (US), and weight-bearing US. METHODS: Forty-seven cases (mean age 43.7 years) with medial meniscus tears and 53 healthy controls (mean age 36.6 years) were assessed. Two experienced sonographers performed the US evaluations, and a fellowship-trained musculoskeletal radiologist assessed the menisci on MRI. Independent and paired T-tests and ICC were used for statistical analyses. RESULTS: On supine US, the mean MME was 3.9 mm for the cases and 2.3 mm for the controls (p < 0.001). On weight-bearing US, the values were 4.2 and 2.8 mm (p < 0.001), and on MRI 3.0 and 2.0 mm (p < 0.001), respectively. The mean difference between supine and weight-bearing US extrusion was 0.38 mm for the cases and 0.49 mm for the controls (p = 0.291). Correlation between supine US and MRI MME measurements was good (ICC = 0.660, CIs [0.533-0.758]). CONCLUSIONS: MME can be assessed using US with good correlation to MRI. US-observed extrusion was significantly increased in supine and standing positions for medial meniscus tears. The mean difference between examination positions was reduced with medial meniscus tears although this result was statistically insignificant.

ESR essentials: MRI of the knee-practice recommendations by ESSR.

Many studies and systematic reviews have been published about MRI of the knee and its structures, discussing detailed anatomy, imaging findings, and correlations between imaging and clinical findings. This paper includes evidence-based recommendations for a general radiologist regarding choice of imaging sequences and reporting basic MRI examinations of the knee. We recommend using clinicians' terminology when it is applicable to the imaging findings, for example, when reporting meniscal, ligament and tendon, or cartilage pathology. The intent is to standardise reporting language and to make reports less equivocal. The aim of the paper is to improve the usefulness of the MRI report by understanding the strengths and limitations of the MRI exam with regard to clinical correlation. We hope the implementation of these recommendations into radiological practice will increase diagnostic accuracy and consistency by avoiding pitfalls and reducing overcalling of pathology on MRI of the knee. CLINICAL RELEVANCE STATEMENT: The recommendations presented here are meant to aid general radiologists in planning and assessing studies to evaluate acute and chronic knee findings by advocating the use of unequivocal terminology and discussing the strengths and limitations of MRI examination of the knee. KEY POINTS: • On MRI, the knee should be examined and assessed in three orthogonal imaging planes. • The basic general protocol must yield T2-weighted fluid-sensitive and T1-weighted images. • The radiological assessment should include evaluation of ligamentous structures, cartilage, bony structures and bone marrow, soft tissues, bursae, alignment, and incidental findings.

Evaluation of Remodeling and Extrusion of Polyurethane Meniscal Implants after Meniscus Reconstruction using Ultrasonography.

INTRODUCTION: Meniscal tears are among the most common indications for knee arthroscopy. Artificial polyurethane scaffolds have demonstrated efficacy in reducing pain and promoting the growth of normal meniscal tissue, with high absorption rates facilitating full tissue regeneration. AIMS: This study aimed to evaluate the remodeling of polyurethane meniscal implants post-reconstruction using ultrasonography. This imaging technique not only assesses changes in implant properties, such as echogenicity, but also the shape changes during functional examination. METHODS: The assessment of meniscal extrusion, comparing size at rest and under weight-bearing, is an indirect parameter that provides insight into the physical properties of the remodeling implant, with greater extrusion indicating reduced stiffness and inferior physical properties of the meniscus. Ultrasonography has the valuable advantage of allowing for assessment of the blood supply to the meniscus through Power Doppler imaging. RESULTS: The presence of vessels within the meniscal implants serves as evidence of ongoing remodeling. The study included 35 patients (13 female, 22 male; mean age 41.6 years, range 18-66) who underwent arthroscopic meniscal reconstruction with polyurethane implants, with an average time from surgery of 2.8 years (range 0.3-4.5 years). Results showed complete (29.7%), significant (45.9%), or moderate (16.2%) remodeling into natural meniscal tissue in 91.8% of the implants. CONCLUSION: The mean values of extrusion in the supine position and during 90-degree flexion were significantly greater in the operated limb (2.603) compared to the contralateral limb (1.978; t(35) = 2.442; P < 0.05). No significant differences in extrusion were found between the limbs in a standing position, indicating favorable physical properties of the polyurethane meniscal implants. Further ultrasonography studies of meniscal scaffolds are deemed relevant.

Meniscal Repair Compared to Meniscectomy for Meniscal Injury: 3-year Outcomes from a Retrospective Cohort Study.

Background: Meniscal injury is a common problem that can lead to knee pain and dysfunction. Meniscal repair and meniscectomy are two treatment approaches for meniscal injury, but the latter may increase the risk of osteoarthritis. We aimed to compare the 3-year outcomes of a new method of meniscal suturing with meniscectomy among patients with meniscal injury. Methods: This retrospective cohort study compared meniscal repair (treatment group) and meniscectomy (control group) in patients with meniscal injury. We evaluated the outcomes of 134 patients. under treatment with these approaches based on the Lysholm scale, which measures knee function and symptoms. The study used the chi-square test and the Mann-Whitney U test to compare the proportion of patients with different outcomes and the Lysholm scale scores between the treatment and control groups. The study also conducted subgroup analyses based on gender and age using the Mann-Whitney U test. The level of significance was set at P < 0.05 for all statistical tests. Results: The treatment group had a higher proportion of patients with excellent results, although the difference was not statistically significant (17.2% in the treatment group vs. 10.0% in the control group, P = 0.223). However, a comparative analysis of the proportion of patients with good results revealed statistically significant differences, with 67.2% of patients in the treatment group achieving good outcomes compared to 45.7% in the control group (χ2 = 6,256, df = 1 P = 0.012, HR 1,470 95%CI 1,081-1,999). The average score on the Lysholm scale was significantly higher in the treatment group (87.48, 95% CI 85.1-89.7, SD = 9.2) compared to the control group (81.73, 95% CI 78.4-84.9, SD = 13.7) (U = 1609, Z = -2.813, P = 0.005). Subgroup analyses based on gender and age also showed significant differences in the Lysholm scale scores. Conclusion: The study demonstrates that meniscal repair is more effective than meniscectomy in improving patient outcomes, with a higher proportion of patients achieving excellent and good results and higher scores on the Lysholm scale. These findings support the use of meniscal repair as a preferred treatment approach for patients with meniscal injuries.

A New Approach to Arthroscopic Stitching of the Knee Joint Meniscus: A Mathematical Justification.

Background: This article presents a mathematical justification for a new approach to arthroscopic stitching of the knee joint meniscus, based on a 3D computer model of the meniscus developed using the COMPASS-3D (APMFEM) program and AutodeskInventorPRO. The research with the patent RK No. 35413 dated 10.12.2021, titled "Method of arthroscopic stitching of the meniscus of the knee joint" builds upon the work of Yu.V. Labunsky. Methods: Mathematical analysis was performed to compare two methods of stitching the meniscus: the new oblique-vertical stitch and the classical vertical stitch. The contact area of the meniscus tissues in the area of the rupture was measured for both stitching methods. Results: The findings demonstrate that the new oblique-vertical stitch offers a 1.5 times larger contact area of the meniscus tissues in the area of the rupture, compared to the classical vertical stitch. Additionally, the new method provides a more significant grip on the radial and circular fibers of the meniscus, surpassing the capabilities of the classic seam. Conclusion: The results of this study can be utilized to develop practical recommendations for traumatologists regarding arthroscopic stitching of the meniscus in the knee joint. The new approach, supported by mathematical analysis and a 3D computer model, offers improved outcomes in terms of contact area and grip on the meniscus fibers, potentially leading to enhanced surgical techniques and patient outcomes.

Medial Meniscotibial Ligament of the Knee: A Step by-Step Dissection.

Objective Considerable attention has been paid to meniscotibial ligaments (MTLs), also known as coronary ligaments, especially after the "Save the Meniscus" initiative gained importance among knee surgeons. Technically challenging, the diagnosis and treatment of ramp lesion show the importance of MTLs. These ligaments were discovered long ago, but their contribution to knee stability has only recently been studied and still lacks information. Thus, the aim of the present study was to describe step-by-step an dissection technique of the medial MTL, efficient, reproducible and that may lead to further research. Method Twenty fresh cadaver knees were used, with no preference for sex or age. The knees were dissected using the same technique standardized by our team. Each dissection step was recorded digitally. Results The medial MTL was found in all 20 knees studied using the aforementioned technique. In our sample, the medial MTL exhibited an average length of 70.0 ± 13.4 mm and width of 32.25 ± 3.09 mm, thickness of 35.3 ± 2.7 mm and weight of 0.672 ± 0.134 g. In all the cases, the medial MTL originated proximally and deeply to the deep MTL in the tibia. Conclusion We describe a simple effective and reproducible medial MTL dissection technique that makes it possible to identify the ligament over the entire medial extension of the knee.

Black discoloration of the knee articular cartilage in a patient with pigmented villonodular synovitis: A case report.

In this case report, total knee arthroplasty was performed in a patient with pigmented villonodular synovitis. During surgery, severe black discoloration of the articular cartilage and menisci was observed in the patient. According to literatures, this is the first case report of severe articular cartilage pigmentation in a patient with pigmented villonodular synovitis.

Wettability and morphology of proboscises interweave with hawkmoth evolutionary history.

Hovering hawkmoths expend significant energy while feeding, which should select for greater feeding efficiency. Although increased feeding efficiency has been implicitly assumed, it has never been assessed. We hypothesized that hawkmoths have proboscises specialized for gathering nectar passively. Using contact angle and capillary pressure to evaluate capillary action of the proboscis, we conducted a comparative analysis of wetting and absorption properties for 13 species of hawkmoths. We showed that all 13 species have a hydrophilic proboscis. In contradistinction, the proboscises of all other tested lepidopteran species have a wetting dichotomy with only the distal ∼10% hydrophilic. Longer proboscises are more wettable, suggesting that species of hawkmoths with long proboscises are more efficient at acquiring nectar by the proboscis surface than are species with shorter proboscises. All hawkmoth species also show strong capillary pressure, which, together with the feeding behaviors we observed, ensures that nectar will be delivered to the food canal efficiently. The patterns we found suggest that different subfamilies of hawkmoths use different feeding strategies. Our comparative approach reveals that hawkmoths are unique among Lepidoptera and highlights the importance of considering the physical characteristics of the proboscis to understand the evolution and diversification of hawkmoths.

Medial meniscal repair in stable knees: Survival rate and risk factors for failure at a minimum of 5 years.

INTRODUCTION: The menisci play a major role in the protection of the knee against osteoarthritis. A medial meniscus (MM) tear occurring in a stable knee is more at risk of repair failure than a suture concomitant with reconstruction of the anterior cruciate ligament. HYPOTHESIS: The survival of MM sutures in stable knees depends on the type of lesion. MATERIALS AND METHODS: This retrospective study was carried out as part of the 2022 Francophone Arthroscopy Society's symposium, across 10 centers (Bordeaux-Mérignac, Caen, Lille, Lille Louvière, Lyon, Marseille, Toulouse, Saint-Étienne, Strasbourg and Versailles) including medial meniscus sutures in stable knees performed before the end of 2017 (minimum 5 years of follow-up) with a collection of demographic, imaging, suture and postoperative protocol data, and a functional evaluation using the Knee injury and Osteoarthritis Outcome score (KOOS). The aim of this study was to analyze the medial meniscus sutures in stable knees and to evaluate their survival and their risk factors for failure according to the type of lesion; failure being defined by the use of a meniscectomy. RESULTS: Three-hundred and sixty-seven MM sutures, including 122 bucket-handle tears, were included. The KOOS score was improved by the meniscal suture by an average of 22.2 points for each sub-score (p<0.05), with an improvement, which was more marked for the bucket-handle tears. The failure rate, defined by revision surgery by meniscectomy, was 33% on average (42% for bucket-handles tears, 26% for others). The probability of survival was reduced for bucket-handle tears (62% at 5 years versus 77% for the other types). For all lesions, the main risk factor identified for failure was immediate weight-bearing [OR=3.6 (1.62; 7.98), p=0.0016]. Smoking was a failure risk factor for bucket-handle tears [OR=5.76 (1.81; 18.35), p=0.003]. CONCLUSION: MM sutures in stable knees improve knee function but present a different risk of failure depending on the type of lesion treated with a higher risk of failure for bucket-handle tears with the need for caution to be applied with regards to weight-bearing and smoking. LEVEL OF EVIDENCE: IV; retrospective series.

Medial Meniscotibial Ligament of the Knee: A Step by-Step Dissection / Ligamento meniscotibial medial do joelho: Uma dissecção passo a passo

Abstract Objective Considerable attention has been paid to meniscotibial ligaments (MTLs), also known as coronary ligaments, especially after the "Save the Meniscus" initiative gained importance among knee surgeons. Technically challenging, the diagnosis and treatment of ramp lesion show the importance of MTLs. These ligaments were discovered long ago, but their contribution to knee stability has only recently been studied and still lacks information. Thus, the aim of the present study was to describe step-by-step an dissection technique of the medial MTL, efficient, reproducible and that may lead to further research. Method Twenty fresh cadaver knees were used, with no preference for sex or age. The knees were dissected using the same technique standardized by our team. Each dissection step was recorded digitally. Results The medial MTL was found in all 20 knees studied using the aforementioned technique. In our sample, the medial MTL exhibited an average length of 70.0 ± 13.4 mm and width of 32.25 ± 3.09 mm, thickness of 35.3 ± 2.7 mm and weight of 0.672 ± 0.134 g. In all the cases, the medial MTL originated proximally and deeply to the deep MTL in the tibia. Conclusion We describe a simple effective and reproducible medial MTL dissection technique that makes it possible to identify the ligament over the entire medial extension of the knee.

Resumo Objetivo Considerável atenção tem sido dada aos ligamentos meniscotibiais (LMT), também conhecidos como ligamentos coronários, especialmente depois que a iniciativa "Salve o Menisco" ganhou importância entre os cirurgiões de joelho. Tecnicamente desafiadores, o diagnóstico e o tratamento da lesão em rampa são importantes nos LMTs. Esses ligamentos foram descobertos há muito tempo, mas sua contribuição para a estabilidade do joelho foi recentemente estudada e ainda carece de informações. Assim, o objetivo deste estudo foi descrever passo a passo uma técnica de dissecção medial do LMT que é eficiente, reprodutível e que possa levar a novas pesquisas. Métodos Foram utilizados 20 joelhos de cadáveres frescos, sem preferência por sexo ou idade. Os joelhos foram dissecados com a mesma técnica padronizada por nossa equipe. Cada etapa da dissecação foi gravada digitalmente. Resultados O LMT medial foi encontrado em todos os 20 joelhos estudados com a técnica supracitada. Em nossa amostra, o LMT medial apresentou comprimento médio de 70,0 ± 13,4 mm e largura de 32,25 ± 3,09 mm, além de espessura de 35,3 ± 2,7 mm e peso de 0,672 ± 0,134 g. Em todos os casos, a origem do LMT medial era proximal e profunda em relação ao LMT profundo na tíbia. Conclusão Descrevemos uma técnica de dissecção simples do LMT medial que é eficaz, reprodutível e permite a identificação do ligamento em toda a extensão medial do joelho.

Repair of meniscus root tear - Is there a difference between medial meniscus root repair and lateral meniscus root repair? A systematic review and meta-analysis.

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 (p < 0.001). Significantly better healing outcomes were observed on reassessment MRI after LMPRT repair (p < 0.001). The postoperative Lysholm score and IKDC score was also significantly better after LMPRT than MMPRT repair (p < 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.

Region- and layer-specific investigations of the human menisci using SHG imaging and biaxial testing.

In this paper, we examine the region- and layer-specific collagen fiber morphology via second harmonic generation (SHG) in combination with planar biaxial tension testing to suggest a structure-based constitutive model for the human meniscal tissue. Five lateral and four medial menisci were utilized, with samples excised across the thickness from the anterior, mid-body, and posterior regions of each meniscus. An optical clearing protocol enhanced the scan depth. SHG imaging revealed that the top samples consisted of randomly oriented fibers with a mean fiber orientation of 43.3 o . The bottom samples were dominated by circumferentially organized fibers, with a mean orientation of 9.5 o . Biaxial testing revealed a clear anisotropic response, with the circumferential direction being stiffer than the radial direction. The bottom samples from the anterior region of the medial menisci exhibited higher circumferential elastic modulus with a mean value of 21 MPa. The data from the two testing protocols were combined to characterize the tissue with an anisotropic hyperelastic material model based on the generalized structure tensor approach. The model showed good agreement in representing the material anisotropy with a mean r 2 = 0.92.

Bilateral Medial and Lateral Discoid Menisci: A Case Report.

Introduction: A discoid meniscus is a typical anatomical variation of the knee. There are several cases of either lateral or medial discoid menisci; however, their combination is rare. We describe a rare instance of bilateral discoid medial and lateral menisci. Case Report: A 14-year-old boy who developed left knee pain after twisting his knee at school was referred to our hospital. He had limited extension of -10°, lateral clicking, and pain on the McMurray test in the left knee and complained of slight clicks in the right knee. Magnetic resonance imaging results for both knees revealed discoid medial and lateral menisci. Surgery was performed on the symptomatic left knee. Arthroscopically, a Wrisberg-type discoid lateral meniscus and an incomplete-type medial discoid meniscus were confirmed. The symptomatic lateral meniscus was saucerized and sutured and only the asymptomatic medial meniscus was observed. The patient was doing well 24 months after surgery. Conclusion: We report a rare case of bilateral medial and lateral discoid menisci.

Histological Findings and T2 Relaxation Time in Canine Menisci of Elderly Dogs-An Ex Vivo Study in Stifle Joints.

Osteoarthritis is a chronic disease that often affects the canine stifle joint. Due to their biomechanical function, the menisci in the canine stifle play an important role in osteoarthritis. They compensate for the incongruence in the joint and distribute and minimize compressive loads, protecting the hyaline articular cartilage from damage. Meniscal degeneration favors the development and progression of stifle joint osteoarthritis. Qualitative magnetic resonance imaging (MRI) is the current golden standard for detecting meniscal changes, but it has limitations in detecting early signs of meniscal degeneration. A quantitative MRI offers new options for detecting early structural changes. T2 mapping can especially visualize structural changes such as altered collagen structures and water content, as well as deviations in proteoglycan content. This study evaluated T2 mapping and performed a histological scoring of menisci in elderly dogs that had no or only low radiographic osteoarthritis grades. A total of 16 stifles from 8 older dogs of different sex and breed underwent ex vivo magnet resonance imaging, including a T2 mapping pulse sequence with multiple echoes. A histological analysis of corresponding menisci was performed using a modified scoring system. The mean T2 relaxation time was 18.2 ms and the mean histological score was 4.25. Descriptive statistics did not reveal a correlation between T2 relaxation time and histological score. Ex vivo T2 mapping of canine menisci did not demonstrate histological changes, suggesting that early meniscal degeneration can be present in the absence of radiological signs of osteoarthritis, including no significant changes in T2 relaxation time.

Gait recovery is not associated with meniscus and/or knee ligament injuries following lateral tibial plateau fractures. A prospective 3-year cohort study of 56 patients.

INTRODUCTION: Though associated meniscus and/or knee ligament injuries following lateral tibial plateau fractures (TPF) are common, the importance of development in gait recovery is unknown. This study aim to report the 12- and 36-month gait recovery in patients with lateral TPF divided into two groups presenting with and without associated meniscus and/or knee ligament injuries. (Associated meniscus and/or knee ligament injuries were grouped as: 1) missing, 2) lateral or medial menisci, 2) posterior and anterior cruciate ligament (PCL/ACL), and 4) lateral or medial collateral ligament.) HYPOTHESIS: Comparable results at the 12- and 36-month follow-up between groups presenting with and without soft tissue injuries. PATIENTS AND METHODS: Study design: cohort study. Included were patients admitted following a lateral TPF (AO-type 41 B) between December 1, 2013 and November 30, 2016. The primary outcome score was gait sample. RESULTS: Fifty-six patients were included. The mean age of the patients at the time of fracture was 56 years (range from 22 to 86). Female gender represents 75%. MRI-verified associated meniscus and/or knee ligament injuries were observed in 28 patients (50%). The average gait speed at the 12- and 36-month follow-up were 125.7 (SD31.3) and 127.7 (SD16.6) cm/sec. for patients with associated meniscus and/or knee ligament injuries and 125.2 (SD31.1) and 130.1 (SD15.6) cm/sec. for patients without associated meniscus and/or knee ligament injuries (p=0.96, p=0.17). Regardless of soft tissue injuries, the development in percent of gait asymmetry for step-length and single-support decrease significantly between the 12- and the 36-month follow-up. (p>0.002) DISCUSSION: This study indicates that gait recovery following lateral TPFs were not associated with associated meniscus and/or knee ligament injuries at the 12- and 36-month follow-up. Between the 12- and 36-month follow-up asymmetry of the gait function decline significantly indicating a prolonged recovery period of gait function following TPFs. LEVEL OF EVIDENCE: II; prospective cohort study.

Ultrashort echo time magnetization transfer imaging of knee cartilage and meniscus after long-distance running.

OBJECTIVE: To assess the detection of changes in knee cartilage and meniscus of amateur marathon runners before and after long-distance running using a 3D ultrashort echo time MRI sequence with magnetization transfer preparation (UTE-MT). METHODS: We recruited 23 amateur marathon runners (46 knees) in this prospective cohort study. MRI scans using UTE-MT and UTE-T2* sequences were performed pre-race, 2 days post-race, and 4 weeks post-race. UTE-MT ratio (UTE-MTR) and UTE-T2* were measured for knee cartilage (eight subregions) and meniscus (four subregions). The sequence reproducibility and inter-rater reliability were also investigated. RESULTS: Both the UTE-MTR and UTE-T2* measurements showed good reproducibility and inter-rater reliability. For most subregions of cartilage and meniscus, the UTE-MTR values decreased 2 days post-race and increased after 4 weeks of rest. Conversely, the UTE-T2* values increased 2 days post-race and decreased after 4 weeks. The UTE-MTR values in lateral tibial plateau, central medial femoral condyle, and medial tibial plateau showed a significant decrease at 2 days post-race compared to the other two time points (p < 0.05). By comparison, no significant UTE-T2* changes were found for any cartilage subregions. For meniscus, the UTE-MTR values in medial posterior horn and lateral posterior horn regions at 2 days post-race were significantly lower than those at pre-race and 4 weeks post-race (p < 0.05). By comparison, only the UTE-T2* values in medial posterior horn showed a significant difference. CONCLUSIONS: UTE-MTR is a promising method for the detection of dynamic changes in knee cartilage and meniscus after long-distance running. KEY POINTS: • Long-distance running causes changes in the knee cartilage and meniscus. • UTE-MT monitors dynamic changes of knee cartilage and meniscal non-invasively. • UTE-MT is superior to UTE-T2* in monitoring dynamic changes in knee cartilage and meniscus.

Epidemiology of Pediatric Meniscectomy: A Nationwide Study in Italy from 2001 to 2016.

In the pediatric population, meniscectomy should be exceptional. This study aimed to estimate the incidence and trends of hospitalization of pediatric meniscectomy in Italy. Data were collected from the National Hospital Discharge Reports (SDO) reported at the Italian Ministry of Health. This study referred to the pediatric population (0-14 years of age) from 2001 to 2016. A total of 5188 pediatric meniscectomies were performed. The global incidence was 3.9 for every 100,000 Italian residents under 14 years of age. The most frequent age class was 10-14 years. The men/women ratio was 1.1. The average number of days of hospitalization was 1.8 ± 1.4. Men showed more days of hospitalization than women. The 5-9 age group presented the highest length of hospitalization (2.3 ± 1.5 days). The main primary codified diagnoses were as follows: derangement of the posterior horn of the medial meniscus, other derangement of the lateral meniscus, old bucket handle tear of the medial meniscus, and derangement of the lateral meniscus. Primary codified procedures were the excision of semilunar cartilage of the knee and knee arthroscopy. The burden of pediatric meniscectomy is relevant in Italy. The information required to develop global standards for managing pediatric meniscal lesions may be provided by conducting further epidemiological studies.

Discoid medial meniscus of both knees: A case report.

BACKGROUND: Discoid meniscus is a congenital anomaly that typically affects the lateral meniscus. The appearance of the discoid medial meniscus in both knees is extremely rare, with an incidence of only 0.012%. CASE SUMMARY: Our patient was a 30-year-old female. Under no obvious predisposing causes, she began to experience pain in both knees, which worsened while walking and squatting. The pain was aggravated after exercise, and joint flexion and extension activities were accompanied by knee snapping. Apley's test was positive on physical examination, and there was a pressing pain in the medial articular space. Plain radiographs of both knees revealed no obvious abnormalities in the bilateral knee joint space. Partial meniscectomy as well as menisci reformation were performed on both knees under arthroscopy. Under the guidance of rehabilitation, the patient's range of motion in both knees returned to normal without pain and knee snapping. CONCLUSION: This study showed that the clinical manifestations of the discoid medial meniscus injury are identical to those of the conventional medial meniscus injury, and arthroscopic surgery is effective.

Meniscal Root Tears: An Update Focused on Preoperative and Postoperative MRI Findings.

Meniscal root tears represent radial tears or avulsions of the meniscal cartilage at the tibial attachment site that profoundly affect meniscal biomechanics and kinematics. Meniscal root tears have the functional effect of a total meniscectomy and can lead to rapid degenerative change with development of early knee osteoarthritis (OA). A growing range of arthroscopic surgical techniques have been developed to repair meniscal root tears with the aim of restoring joint kinematics and contact pressures and delaying the development of OA. With increased understanding of the anatomy and biomechanics of the meniscal root, meniscal root injury repair has become the treatment of choice in knees with nonadvanced OA. This article reviews the anatomy and biomechanics of the meniscal roots, clinical and imaging diagnostic criteria of meniscal root tears, correlation between arthroscopy and MRI in the diagnosis and classification of meniscal root tears, and expected and abnormal MRI findings after meniscal root repair. Familiarity with MRI signs and classifications of meniscal root tears, as well as with root repair surgical techniques, can aid radiologists in correctly reporting preoperative and postoperative MRI findings.