The novel epiligament theory: differences in healing failure between the medial collateral and anterior cruciate ligaments

According to current literature, 90% of knee ligament injuries involve the medial collateral ligament or the anterior cruciate ligament. In contrast to the medial collateral ligament, which regenerates relatively well, the anterior cruciate ligament demonstrates compromised healing. In the past, there were numerous studies in animal models that examined the healing process of these ligaments, and different explanations were established. Although the healing of these ligaments has been largely investigated and different theories exist, unanswered questions persist.Therefore, the aim of this article is 1) to review the different historical aspects of healing of the medial collateral ligament and present the theories for healing failure of the anterior cruciate ligament; 2) to examine the novel epiligament theory explaining the medial collateral ligament healing process and failure of anterior cruciate ligament healing; and 3) to discuss why the enveloping tissue microstructure of the aforementioned ligaments needs to be examined in future studies.We believe that knowledge of the novel epiligament theory will lead to a better understanding of the normal healing process for implementing optimal treatments, as well as a more holistic explanation for anterior cruciate ligament healing failure.

The Top 50 Most Cited Publications in Meniscus Research

Injuries to the menisci of the knee are common in orthopedic sports medicine. Bibliometric studies can identify the core literature on a topic and help further our collective knowledge for both clinical and educational purposes. The purpose of the current study was to (1) identify and describe the 50 most cited articles in meniscus research over an 80-year time period to capture a wide range of influential articles and (2) identify the “citation classics” and milestone articles related to the meniscus of the knee. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched for the 50 most cited meniscus articles. Data pertaining to bibliometric and publication characteristics were extracted and reported using descriptive statistics. The top 50 articles were published between the years 1941 and 2014 and collectively cited 13,152 times. The median (interquartile [IQR]) number of total citations per article was 203.5 (167.0–261.8), while the median citation rate was 9.6 (7.4–13.9) citations per year. The most cited article was “Knee joint changes after meniscectomy,” published in 1948. The article with the highest citation rate of 78.4 citations per year was “The long-term consequence of anterior cruciate ligaments and meniscus injuries – osteoarthritis,” published in 2007. The majority of articles were clinical outcome studies (n = 28, 56%). The top 50 most cited meniscus articles represent a compilation of highly influential articles which may augment reading curriculums and provide a strong knowledge base for orthopaedic surgery residents and fellows. The decade with the most articles was the 2000s, representing a recent acceleration in meniscus-based research. This is a level IV, cross-sectional study.

Prevalence and Structural Abnormal Findings of Injured Knee Joint among Adult Patients detected by Magnetic Resonance Imaging Study of 70 Cases in a tertiary hospital of Bangladesh

Background: Magnetic resonance imaging is a very useful diagnostic tool for the detection of abnormalities of injured knee joint. Objective: This present study was performed to see the different abnormalities of injured knee joint detected by MRI among adult patients. Methodology: This cross-sectional study was conducted in the Department of Radiology and Imaging at Bangabandhu Sheikh Mujib Medical University (BSSMU), Dhaka, Bangladesh from January to June 2021 for a period of six months. The patients in the age group of equal or more than 18 years with both male and female who were visiting Department of Orthopaedics at BSMMU, Dhaka with history of knee injuries were subjected to MRI were selected as study population. MRI findings of the knee joint were analyzed for the presence of any signal changes or lesions of varying severity for the structures of menisci, cartilage, bone marrow, tendons and ligaments of injured knee joint. Results: A total number of 65 cases of knee joints were analyzed. The mean with the SD of age of the study population was 35.34±13.371. The left knee (60.0%) was more involved than right knee (40.0%). The lesion in femur and tibia were found in 10(15.4%) cases and 8(12.3%) cases respectively. Out of 65 knee joints there were 41 joints were found the tear of anterior cruciate ligament. The complete, interstial tear in the anterior cruciate ligaments were 26(40.0%) and 15(23.1%) knee joints respectively. However, anterior cruciate ligaments of 24(36.9%) knee joints were found normal. Medial meniscus (36.9%) was more involved than lateral meniscus (18.5%). Conclusion: In conclusion young adult male are more commonly affected their left knee joint with the tearing of complete tear of anterior cruciate ligaments and involvement of medial meniscus. Journal of Current and Advance Medical Research, July 2021;8(2):80-84

Diagnostic Accuracy of Anterior Draw Test and MRI for Assessing ACL Tears of the Knee

Cruciate ligaments are most commonly effected by any hard force applied on them. In cruciate ligaments anterior cruciate ligaments are mostly effected. As a result of which severe pain occurs in the joint.

Small RNA signatures of the anterior cruciate ligament from patients with knee joint osteoarthritis

The anterior cruciate ligaments are susceptible to degeneration, resulting in pain, reduced mobility and development of the degenerative joint disease osteoarthritis. There is currently a paucity of knowledge on how anterior cruciate ligament degeneration and disease can lead to osteoarthritis. Small non-coding RNAs (sncRNAs), such as microRNAs, and small nucleolar RNA, are important regulators of gene expression. We aimed to identify sncRNA profiles of human anterior cruciate ligaments to provide novel insights into their roles in osteoarthritis. RNA was extracted from the anterior cruciate ligaments of non-osteoarthritic knee joints (control) and end-stage osteoarthritis knee joints, used for small RNA sequencing and significantly differentially expressed sncRNAs defined. Bioinformatic analysis was undertaken on the differentially expressed miRNAs and their putative target mRNAs to investigate pathways and biological processes affected. Our analysis identified 184 sncRNA that were differentially expressed between control ACLs derived from osteoarthritic joints with a false discovery adjusted p value<0.05; 68 small nucleolar RNAs, 26 small nuclear RNAs and 90 microRNAs. We identified both novel and previously identified (miR-206, -101, -365 and -29b and -29c) osteoarthritis-related microRNAs and other sncRNAs (including SNORD74, SNORD114, SNORD72) differentially expressed in ligaments derived from osteoarthritic joints. Significant cellular functions deduced by the differentially expressed miRNAs included differentiation of muscle (P<0.001), inflammation (P<1.42E−10), proliferation of chondrocytes (P<0.03), fibrosis (P<0.001) and cell viability (P<0.03). Putative mRNAs were associated with the canonical pathways Hepatic Fibrosis Signalling (P<3.7E-32), and Osteoarthritis (P<2.2E−23). Biological processes included apoptosis (P<1.7E−85), fibrosis (P<1.2E−79), inflammation (P<3.4E−88), necrosis (P<7.2E−88) and angiogenesis (P<5.7E−101). SncRNAs are important regulators of anterior cruciate disease during osteoarthritis and may be used as therapeutic targets to prevent and manage anterior cruciate ligament disease and the resultant osteoarthritis.

The complexity of molecular processes in osteoarthritis of the knee joint

Osteoarthritis (OA) is a common medical problem leading to chronic pain and physical disability among the world’s population. Analyzing the molecular background of the degenerative arthritis creates the potential for developing novel targeted methods of treatment. Fifty samples of meniscus, anterior cruciate ligaments (ACLs) and articular surfaces were collected from patients who underwent total knee arthroplasty in 2016. Enzyme-linked immunosorbent assay was used to assess the levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF), transforming growth factor-β1 and LUMINEX for MMP-1, MMP-2, MMP-3, MMP-9 and MMP-13. The collected data were correlated with the severity of radiological OA, demographic data and clinical scales. Strong positive correlations in the concentration of metalloproteinases and proinflammatory cytokines, TNF-α (MMP-2 and MMP-13) and IL-6 (MMP-13), were identified. MMP-13 had a positive correlation with the concentration of MMP-1, MMP-2 and MMP-9. Negative correlation coefficient exists between clinical conditions measured with the Western Ontario and McMaster Universities Osteoarthritis Index scale and the level of TNF-α and MMP-1. The TNF-α concentration was lower in the cartilage of the articular surface among patients who took non-steroidal anti-inflammatory drugs periodically. The decrease in MMP-2 in the cartilage of the articular surface corresponded with the severity of radiological OA on the Kellgren–Lawrence scale. Current treatment methods for OA do not stop disease progression. Identifying signaling pathways and molecular particles engaged in OA and their correlations with the patient’s clinical condition brings new therapeutic possibilities.

Protocol for a systematic review of paediatric meniscal repair

Background Meniscal tears in the paediatric population represent a significant challenge. Improved sensitivity of diagnostic imaging and increased intensity of organised sport among children is in part responsible for an increased incidence of injuries identified. While rare, these injuries have a significant impact on a patient’s future and necessitate timely and meticulous repair. Methods Adhering to PRISMA guidelines, MEDLINE, Embase and Cochrane databases will be interrogated from inception to November 2019. All primary clinical studies in which paediatric meniscal injuries are treated will be identified and included. Treatment techniques will be grouped according to surgical technique and a further analysis of any papers concomitantly repair anterior cruciate ligaments will also be analysed to identify any superiority. A qualitative synthesis will at first be attempted with further quantitative analysis should heterogeneity of studies allow it. Discussion Paediatric meniscal injuries provide a dilemma for even the most experience surgeon, with no consensus on a preferred treatment option. Outcomes are often poor and can have long-term effects with early onset of osteoarthritis and limitation of future function. As such, this review will be pivotal in identifying the different treatment options being employed for meniscal repair in a paediatric population, if there is any superiority in a given treatment choice and moving towards identified a standard treatment protocol.

SV40 Transfected Human Anterior Cruciate Ligament Derived Ligamentocytes—Suitable as a Human in Vitro Model for Ligament Reconstruction?

Cultured human primary cells have a limited lifespan undergoing dedifferentiation or senescence. Anterior cruciate ligaments (ACL) are hypocellular but tissue engineering (TE) requires high cell numbers. Simian virus (SV) 40 tumor (T) antigen expression could extend the lifespan of cells. This study aimed to identify cellular changes induced by SV40 expression in human ACL ligamentocytes by comparing them with non-transfected ligamentocytes and tissue of the same donor to assess their applicability as TE model. Human ACL ligamentocytes (40-year-old female donor after ACL rupture) were either transfected with a SV40 plasmid or remained non-transfected (control) before monitored for SV40 expression, survival, and DNA content. Protein expression of cultured ligamentocytes was compared with the donor tissue. Ligamentocyte spheroids were seeded on scaffolds embroidered either from polylactic acid (PLA) threads solely or combined PLA and poly (L-lactide-co-ε-caprolactone) (P(LA-CL)) threads. These scaffolds were further functionalized with fluorination and fibrillated collagen foam. Cell distribution and survival were monitored for up to five weeks. The transfected cells expressed the SV40 antigen throughout the entire observation time, but often exhibited random and incomplete cell divisions with significantly more dying cells, significantly more DNA and more numerous nucleoli than controls. The expression profile of non-transfected and SV40-positive ligamentocytes was similar. In contrast to controls, SV40-positive cells formed larger spheroids, produced less vimentin and focal adhesions and died on the scaffolds after 21 d. Functionalized scaffolds supported human ligamentocyte growth. SV40 antigen expressing ligamentocytes share many properties with their non-transfected counterparts suggesting them as a model, however, applicability for TE is limited.