Evaluation of the usefulness of non-weight-bearing tunnel view using X-ray in the short term after medial meniscus posterior root tear onset: a retrospective study.

BACKGROUND: This study aimed to examine whether the non-weight-bearing tunnel view X-ray is effective for short-term evaluation of medial meniscus posterior root tear (MMPRT) by assessing the X-ray characteristics at the initial and follow-up visits. METHODS: This was a retrospective longitudinal study of 26 enrolled knees diagnosed with MMPRT on magnetic resonance imaging. The distance between the medial tibial eminence and medial femoral condyle (MTE-MFC distance) and medial tibiofemoral joint (MTFJ) width were measured by obtaining non-weight-bearing tunnel view and frontal view X-ray radiographs. The initial and follow-up values at a median interval of 17 days were compared. Additionally, the correlations between the MTE-MFC distance increase rate and body mass index (BMI), age, femorotibial angle (FTA), and posterior tibial slope (PTS) were evaluated using linear regression analysis. RESULTS: The tunnel view images of the initial and follow-up X-rays showed a significant increase in the MTE-MFC distance and a significant decrease in the MTFJ width. Furthermore, a moderate correlation was observed between the change in the MTE-MFC distance and the time interval between X-rays. However, no substantial correlation was observed for the change in the MTFJ width over time. Moreover, no significant correlation was observed between the change in the MTE-MFC distance in the non-weight-bearing tunnel view and BMI, age, FTA, and PTS. CONCLUSIONS: The non-weight-bearing tunnel view is highly beneficial for evaluating MMPRT progression in the short term.

Meniscal Lesions in Multi-Ligament Knee Injuries.

Introduction: Multi-ligament knee injuries (MLKIs) are rare and complex knee lesions and are potentially associated with intra-articular injuries, especially meniscal tears. Understanding the meniscal tear patterns involved in MLKI can help the orthopedic surgeon treat these complex injuries. Objective: The purpose of this study was to describe the incidence, classification, and treatment of meniscal injuries in a cohort of patients with MLKIs and carry out an updated review of the evidence available. Materials and methods: Descriptive retrospective study. Patients with a history of reconstructive surgery for MLKI performed between 2013 and 2023 were included. Informed consent was obtained from all patients included in the study. Patient demographics, magnetic resonance imaging (MRI) study, and operative reports were reviewed. Groups were then formed based on ligament injury patterns. Meniscal tears were identified by MRI and through diagnostic arthroscopy for each patient. The association between meniscal lesions and injury patterns was calculated through Fisher's exact test. Agreement between the presence of meniscal tear on MRI and in diagnostic arthroscopy was measured using the kappa test. The sensitivity and specificity of MRI were calculated. We inferred the presence of a meniscal tear by injury pattern using the Agresti-Coull confidence interval. For the statistical analysis, a significance of 5% and a confidence interval of 95% were considered. Results: Seventy patients with MLKIs were included, with a mean age of 30.69 years (SD 10.65). Forty-seven patients had meniscal lesions (67.1%). Of them, 6 had only medial meniscus tears, 31 had only lateral meniscus tears, and 10 had lesions of both menisci, comprising 57 meniscal lesions in total. An anterior cruciate ligament (ACL) + medial collateral ligament/posteromedial corner (MCL/PMC) was the most common injury pattern (52.86% of all patients). Of these 37 patients, 78.38% had meniscal injuries, and most of them (68.97%) were only lateral meniscus injuries. The odds ratio (OR) of having a meniscal tear when having an ACL + medial-side injury was 4.83 (95% CI; 0.89-26.17). Patients with ACL + lateral-side injury pattern had meniscal tears in 42.86%. The lateral meniscus was involved in 100% of these patients. 62.5% of medial meniscus injuries were treated by meniscal repair, and 37.5% by partial meniscectomy. 58.54% of lateral meniscus injuries were treated by meniscal repair, and 39.02% by partial meniscectomy. Agreement calculated using the kappa test between MRI and diagnostic arthroscopy for medial meniscal lesions was 78.57%, and for lateral meniscal lesions was 84.29%. Conclusion: The ligament injury pattern and the side of the injured collateral ligament influenced the incidence and laterality of meniscal damage. ACL + medial-side injuries were shown to have significantly greater meniscal damage compared to other injury patterns. It is crucial to have a high index of suspicion, obtain a high-quality MRI, and arthroscopically evaluate any possible meniscal lesions in MLKIs.

Knee Arthroscopic Surgery in Middle-Aged Patients With Meniscal Symptoms: A 10-Year Follow-up of a Prospective, Randomized Controlled Trial.

BACKGROUND: Short- and midterm evaluations of arthroscopic meniscal surgery have shown little or no effect in favor of surgery, although long-term effects, including radiographic changes, are unknown. PURPOSE: To compare the 10-year outcomes in middle-aged patients with meniscal symptoms between a group that received an exercise program alone and a group that received knee arthroscopy in addition to the exercise program with respect to the prevalence of radiographic and symptomatic osteoarthritis (OA), patient-reported outcomes, and clinical status. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Of 179 eligible patients aged 45 to 64 years, 150 were randomized to undergo either 3 months of exercise therapy (nonsurgery group) or knee arthroscopy in addition to the exercise therapy (surgery group). Surgery usually consisted of partial meniscectomy (n = 56) or diagnostic arthroscopy (n = 8). Radiographs were assessed according to the Kellgren-Lawrence score at the baseline and 5- and 10-year follow-ups. Patient-reported outcome measures were reported at the baseline and 1-, 3-, 5-, and 10-year follow-ups. Clinical status was assessed at a 10-year follow-up. The primary outcomes were radiographic OA and changes in the Knee injury and Osteoarthritis Outcome Score Pain subscale (KOOSPAIN) from the baseline to the 10-year follow-up. The primary analysis was performed using the intention-to-treat approach. RESULTS: At the time of the 10-year follow-up, eight patients had died, leaving 142 eligible patients. Radiographic OA was assessed for 95 patients (67%), questionnaires were answered by 110 (77%), and the clinical status was evaluated for 95 (67%). Radiographic OA was present in 67% of the patients in each group (P≥ .999); symptomatic OA was present in 47% of the nonsurgery group and 57% of the surgery group (P = .301). There were no differences between groups regarding changes from baseline to 10 years in any of the KOOS subscales. CONCLUSION: Knee arthroscopic surgery, in most cases consisting of partial meniscectomy or diagnostic arthroscopy, in addition to exercise therapy in middle-aged patients with meniscal symptoms, did not increase the rates of radiographic or symptomatic OA and resulted in similar patient-reported outcomes at the 10-year follow-up compared with exercise therapy alone. Considering the short-term benefit and no long-term harm from knee arthroscopic surgery, the treatment may be recommended when first-line treatment-including exercise therapy for ≥3 months-does not relieve patient's symptoms. REGISTRATION: Clinical Trials NCT01288768 (ClinicalTrials.gov identifier).

Degenerative medial and lateral menisci root tears: demographics, clinical presentation, imaging features, and associated findings.

PURPOSE: (I) Characterize the demographics and clinical features of patients with meniscal root tears (MRT); (II) analyze the morphology, extent, and grade of MRT on MRI; (III) evaluate associated abnormalities on imaging; and (IV) evaluate the associations between imaging findings, demographics, clinical features, and joint structural abnormalities. MATERIAL AND METHODS: A search was performed to identify meniscal root tears. Age, sex, BMI, and pain were recorded. Knee radiographs and MRI were reviewed. Presence, grade and morphology of MRT, meniscal extrusion, insufficiency fractures, as well as joint structural abnormalities were scored. For goals (I), (II), and (III), tabulations for categorical variables and mean for continuous variables were computed. MRT findings variables were described using percentages. For goal (IV), adjusted linear and logistic regression were employed. RESULTS: Ninety-six patients with a mean age of 56.6 years (69 females) and mean BMI of 28.9 kg/m2 were included; 88 of the MRT were located at the posterior horn of the medial meniscus (PHMM), and 82% were radial tear. The mean tear diameter was 3.8 mm, and 78/96 tears presented with meniscal extrusion. Nineteen patients presented with subchondral insufficiency fracture (SIF), which was significantly associated with the gap of the tear (p = 0.001) and grade of the meniscal root lesion (p = 0.005). CONCLUSION: MRT typically found in middle-aged to older overweight and obese women. Lesions were mostly radial tears and located at PHMM and were frequently associated with meniscal extrusion and SIF. Moreover, the presence of SIF was significantly associated with the gap width and grade of root tear.

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.

The predictive value of point-of-care ultrasonography versus magnetic resonance imaging in assessing medial meniscal tears in patients with acute knee injury.

OBJECTIVE: Musculoskeletal ultrasound is increasingly used as the modality of choice in diagnosing many medical situations. The present study aimed to compare the accuracy of point-of-care ultrasonography (POCUS) and magnetic resonance imaging (MRI) to detect acute medial meniscus tears in knee. METHODS: The prospective study was conducted on patients with suspected medial meniscus tears in knee. in the emergency department. In the absence of a knee fracture on x-ray, POCUS on the knee was performed. All patients underwent POCUS and MRI of the knee followed by arthroscopy. POCUS findings were then compared to MRI findings to diagnose medial meniscus tears. RESULTS: A final total of 157 patients with a mean age of 25.04±7.41 years was included. Out of 157 patients, 94 (59.9%) were male. Medial meniscus tears were detected in 89 patients (56.7%) using arthroscopy as the gold standard. The sensitivity, specificity, positive and negative predictive values, and accuracy of POCUS to detect medial meniscus tears were 88.8% (95% confidence interval [CI], 80.3%-94.5%), 89.7% (95% CI, 79.9%-95.8%), 91.9% (95% CI, 84.8%-95.8%), 85.9% (95% CI, 77.2%-91.7%), and 89.2% (95% CI, 83.3%-93.6%), respectively. The diagnostic accuracy of MRI to detect medial meniscus injury was 93.0% (95% CI, 87.8%- 96.4%). CONCLUSION: The present study demonstrated that POCUS is an accurate and reliable diagnostic tool alternative to MRI in detecting medial meniscal tears. POCUS had acceptable sensitivity, specificity, and accuracy in detecting meniscal injuries and could be performed as an effective immediate investigation to guide further modalities in patients with acute knee trauma.

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.

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.

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.

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.

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.

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.

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.