Traumatic Meniscal Tears Are Associated With Meniscal Degeneration

Predictors of Postoperative Outcomes after Arthroscopic Partial Meniscectomy: A Retrospective Analysis

OBJECTIVE

Arthroscopic partial meniscectomy is a widely used surgical technique for treating meniscus injuries, while individual differences in postoperative outcomes remain a significant concern. This retrospective study aimed to identify the factors influencing clinical outcomes following arthroscopic partial meniscectomy.

METHODS

We retrospectively examined the clinical data of 52 patients who underwent arthroscopic partial meniscectomy at our institution from January to May 2022. Observation indicators, including gender, age, type of medical insurance, various surgeons, the self-pay portion of hospital costs, and total hospital costs, were systematically recorded. Subjective symptoms were evaluated with ΔTenger, ΔLysholm, and International Knee Documentation Committee (IKDC) scores during follow-up. The trends of the above questionnaires and potential predictors were statistically evaluated through regression analysis.

RESULTS

Binary logistic analysis revealed that female patients (OR: 32.42; 95% confidence interval [CI]: 2.22, 473.86) and higher preoperative visual analog scale (VAS) (odds ratio [OR]: 3.58; 95% CI: 1.55, 8.28) were significantly associated with FP Lysholm score. Similarly, patients with elevated preoperative VAS (OR: 1.47; 95% CI: 1.01, 2.15) were significantly more likely to have FP IKDC scores. Multiple linear regression analysis revealed that traumatic meniscus tear (β = -0.324; 95% CI: -0.948, -0.036; p = 0.035) emerged as a negative independent predictor of ΔTegner, while higher preoperative VAS scores (β = 0.330; 95% CI: 0.013, 0.217; p = 0.028) were identified as positive independent predictors of ΔTegner. The duration of symptoms (β = -0.327; 95% CI: -0.010, -0.001; p = 0.023) had a negative impact on the ΔLysholm scores. Factors such as body mass index (BMI) (β = -0.250; 95% CI: -1.000, -0.020; p = 0.042), duration of symptoms (β = -0.302; 95% CI: -0.009, -0.001; p = 0.014), and preoperative VAS (β = -0.332; 95% CI: -1.813, -0.250; p = 0.011) were negatively associated with ΔIKDC scores.

CONCLUSION

The study offers insights into multiple factors for patient outcomes after arthroscopic partial meniscectomy. Orthopedic surgeons need to consider variables such as gender, BMI, duration of symptoms, preoperative VAS, and the traumatic/degenerative types of meniscal tears to optimize postoperative outcomes.

Impact of lower limb alignment abnormality (physiologic knee valgus) on the functional recovery outcome of athletes with meniscal injuries

OBJECTIVE

This study aimed to investigate the impact of lower limb alignment abnormalities, specifically physiological knee valgus, on the functional recovery outcomes of athletes with meniscal injuries. It also examined the factors influencing these abnormalities to provide scientific evidence for treatment and rehabilitation of related sports injuries.

METHODS

We conducted a retrospective study of 118 athletes from Guizhou Normal University, who were divided into two groups based on the presence or absence of lower limb alignment abnormalities. The Simple group comprised athletes with isolated meniscal injuries, while the Combined group included athletes with meniscal injuries and concurrent lower limb alignment abnormalities. We assessed the functional status of both groups and analyzed factors influencing lower limb alignment abnormalities.

RESULTS

Of the 118 athletes, 46 (38.98%) exhibited lower limb alignment abnormalities, and 72 (61.02%) did not. No significant differences in general characteristics were found between the groups (all P > 0.05). The Combined group displayed higher Visual Analog Scale (VAS) scores and Functional Performance Test (FPT) results (coordinated contraction, shuttle run, CarioCa) compared to the Simple group (P < 0.05). Conversely, joint range of motion (ROM), knee muscle strength (flexors), and International Knee Documentation Committee (IKDC) scores were lower in the Combined group (all P < 0.05). Multivariate logistic regression analysis identified active ROM < 105.32°, passive ROM < 101.66°, and knee muscle strength (flexors) < 84.41 N as risk factors for lower limb alignment abnormalities (P < 0.05), while FPT acted as a protective factor (P < 0.05). The combined testing model demonstrated higher predictive efficacy (AUC = 0.903, 95% CI: 0.852-0.955, P < 0.001).

CONCLUSION

Lower limb alignment abnormalities significantly affect the functional recovery outcomes of athletes with meniscal injuries. Factors such as ROM, knee muscle strength, and IKDC score may pose risks for these abnormalities, whereas FPT can provide protective benefits. Timely detection and correction of lower limb alignment abnormalities during the rehabilitation process from meniscal injuries are crucial to enhance recovery and improve prognosis.

Costs and Timing of Surgery in the Management of Meniscal Tears

Background

Treatment strategies for meniscal tears range from nonoperative management to surgical intervention. However, national trends in cost-related outcomes and patient factors related to the failure of nonoperative management remain poorly understood.

Purpose

To describe the costs associated with nonoperative versus operative management of meniscal tears in the 2 years after diagnosis and examine the relationship between patient characteristics and timing of surgery.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

This study was conducted using the MarketScan databases. Patients diagnosed with a meniscal tear without concomitant knee osteoarthritis between January 1 and December 31, 2017, were included. The primary outcome was the total cost of meniscal tear-related procedures-including insurance deductibles, coinsurance, and net insurance payments-in the 2 years after diagnosis. Procedures included were as follows: (1) surgery-including meniscectomy or meniscal repair; (2) physical therapy; (3) medication-including nonsteroidal anti-inflammatories, opioids, and acetaminophen; (4) intra-articular injections-including professional fee, hyaluronic acid, and corticosteroids; (5) imaging; and (6) clinic visits to orthopaedic specialists. Patients were grouped as having undergone early surgery (ES) (≤3 months of diagnosis), late surgery (LS) (>3 months after diagnosis), or no surgery (NS). Multivariate logistic regression was performed to determine the likelihood of undergoing surgery early and failing nonoperative treatment.

Results

The study population included 29,924 patients with a mean age of 43.9 ± 12.9 years (ES: n = 9507 (31.8%); LS: n = 2021 (6.8%); NS: n = 18,396 (61.5%)). Complex (36.6%) and medial (58.8%) meniscal tears were the most common type and location of injuries, respectively. The mean cost of management per patient was $3835 ± $4795. Costs were lower in the NS group ($1905 ± $3175) compared with the ES group ($6759 ± $5155), while the highest costs were observed in the LS group ($7649 ± $5913) (P < .001). Patients who were men, >40 years, and with a bucket-handle or lateral meniscal tear were more likely to undergo surgery early. Patients who were men, <30 years, and with a complex tear or tear to the lateral meniscus were more likely to fail nonoperative management.

Conclusion

Nonoperative management had the lowest cost burden and should be recommended for patients with appropriate indications. However, if surgery is necessary, it should be performed earlier.

Identifying autophagy-related mRNAs and potential ceRNA networks in meniscus degeneration based on RNA sequencing and experimental validation

Purpose

The intimate connection between long noncoding RNA (lncRNA) and autophagy has been established in cartilage degeneration. However, their roles in meniscal degeneration remain ambiguous. This study aimed to identify the key autophagy-related lncRNA and its associated regulatory network in meniscal degeneration in the context of osteoarthritis (OA).

Methods

RNA sequencing was performed to identify differentially expressed lncRNAs (DELs) and mRNAs (DEMs), which were then conducted to enrichment analyses using the DAVID database and Metascape. Autophagy-related DEMs were identified by combining DEMs with data from the Human Autophagy Database. Three databases were used to predict miRNA, and the DIANA LncBase Predicted database was utilized to predict miRNA-lncRNA interactions. Based on these predictions, comprehensive competitive endogenous RNA (ceRNA) network were constructed. The expression levels of the classical autophagy markers and autophagy-related ceRNA network were validated. Additionally, Gene Set Enrichment Analysis (GSEA) was performed using autophagy-related DEMs.

Results

310 DELs and 320 DEMs were identified, with five upregulated and one downregulated autophagy-related DEMs. Through reverse prediction of miRNA, paired miRNA-lncRNA interactions, and verification using RT-qPCR, two lncRNAs (PCAT19, CLIP1-AS1), two miRNA (has-miR-3680-3p and has-miR-4795-3p) and two mRNAs (BAG3 and HSP90AB1) were included in the constructed ceRNA regulatory networks. GSEA indicated that the increased expression of autophagy-related mRNAs inhibited glycosaminoglycan biosynthesis in the degenerative meniscus.

Conclusion

This study presented the first construction of regulatory ceRNA network involving autophagy-related lncRNA-miRNA-mRNA interactions in OA meniscus. These findings offered valuable insights into the mechanisms underlying meniscal degeneration and provided potential targets for therapeutic intervention.

Improved Outcome With Knee Arthroscopy Relative to Physiotherapy for Symptomatic Unstable Meniscal Tears: 2-Year Prospective Cohort Study

BACKGROUND

Although preservation of meniscal tissue is paramount, there are occasions when repair of a torn meniscus is not possible. The surgical option may be a partial meniscectomy, the objective being to alleviate the patient's symptoms with resection of only that portion of the meniscus that is no longer functioning but is the cause of symptoms. Previous studies have questioned the need to perform such surgery and have recommended nonoperative treatment instead. Our goal was to compare the outcome of partial meniscectomy with that of physiotherapy alone for irreparable meniscal tears.

HYPOTHESIS

Clinical outcome following arthroscopic partial meniscectomy may differ from that following physiotherapy alone, for patients with symptomatic irreparable meniscal tears.

STUDY DESIGN

Nonrandomized prospective cohort study.

LEVEL OF EVIDENCE

Level 2.

METHODS

Patients satisfying the inclusion criteria chose to undergo knee arthroscopy (group A) or physiotherapy (group B). The diagnosis of a meniscal tear was made on physical assessment and magnetic resonance imaging examination. The meniscal tear was preventing them from continuing with their regular weightbearing exercise. Outcomes of interest were the following patient-reported outcomes (PROs): the Knee Osteoarthritis Outcome Score (KOOS) and Tegner Activity Score (TAS), with minimal clinically important differences being 10 and 1, respectively. PROs were completed at baseline, and at 1-year and 2-year follow-up. Changes in scores within and between groups were compared using analysis of variance and Wilcoxon tests (P <0.05). A power analysis demanded 65 patients in each group to produce a power of 80% and a P value of 5%.

RESULTS

Of 528 patients enrolled in the study, 10 were lost to follow-up and 8 were excluded. Data were complete for 269 in group A, and 228 in Group B. Group A and B were similar in terms of age (41.1 years, SD 7.8 vs 40 years, SD 13.3), body mass index (22.5 kg/m2, SD 3.1 vs 23.1 kg/m2, SD 2.3), radiographic grade of osteoarthritis (median grade 2, range 0-3 in both groups), gender (male:female = 134:135 vs 112:116), and duration of symptoms (44.4 days, SD 5.6 vs 46.6 days, SD 8.8), with P >0.05. At both 1-year and 2-year follow-up, Group A had higher scores in the mean total KOOS (88.8, SD 8.0 vs 72.4, SD 3.8), as well as in all subscales within the KOOS, and the TAS (median 7, range 5-9 vs median 5, range 3-6), with P <0.001 for each variable.

CONCLUSION

Performing a knee arthroscopy with partial meniscectomy is associated with improved KOOS and TAS, relative to treatment with physiotherapy alone, at 2-year follow-up.

CLINICAL RELEVANCE

Physically active patients with symptomatic irreparable meniscal tears may experience a better clinical outcome following knee arthroscopy, relative to to physiotherapy alone.

Post-traumatic and OA-related lesions in the knee at baseline and 2 years after traumatic meniscal injury: Secondary analysis of a randomized controlled trial

OBJECTIVE

To assess the presence of early degenerative changes on Magnetic Resonance Imaging (MRI) 24 months after a traumatic meniscal tear and to compare these changes in patients treated with arthroscopic partial meniscectomy or physical therapy plus optional delayed arthroscopic partial meniscectomy.

DESIGN

We included patients aged 18-45 years with a recent onset, traumatic, MRI verified, isolated meniscal tear without radiographic osteoarthritis. Patients were randomized to arthroscopic partial meniscectomy or standardized physical therapy with optional delayed arthroscopic partial meniscectomy. MRIs at baseline and 24 months were scored using the MRI Osteoarthritis Knee Score (MOAKS). We compared baseline MRIs to healthy controls aged 18-40 years. The outcome was the progression of bone marrow lesions (BMLs), cartilage defects and osteophytes after 24 months in patients.

RESULTS

We included 99 patients and 50 controls. At baseline, grade 2 and 3 BMLs were present in 26% of the patients (n = 26), compared to 2% of the controls (n = 1) (between group difference 24% (95% CI 15% to 34%)). In patients, 35% (n = 35) had one or more cartilage defects grade 1 or higher, compared to 2% of controls (n = 1) (between group difference 33% (95% CI 23% to 44%)). At 24 months MRI was available for 40 patients randomized to arthroscopic partial meniscectomy and 41 patients randomized to physical therapy. At 24 months 30% (n = 12) of the patients randomized to arthroscopic partial meniscectomy showed BML worsening, compared to 22% (n = 9) of the patients randomized to physical therapy (between group difference 8% (95% CI -11% to 27%)). Worsening of cartilage defects was present in 40% (n = 16) of the arthroscopic partial meniscectomy group, compared to 22% (n = 9) of the physical therapy group (between group difference 18% (95% CI -2% to 38%)). Of the patients who had no cartilage defect at baseline, 33% of the arthroscopic partial meniscectomy group had a new cartilage defect at follow-up compared to 14% of the physical therapy group. Osteophyte worsening was present in 18% (n = 7) of the arthroscopic partial meniscectomy group and 15% (n = 6) of the physical therapy group (between group difference 3% (95% CI -13% to 19%)).

CONCLUSIONS

Our results might suggest more worsening of BMLs and cartilage defects with arthroscopic partial meniscectomy compared to physical therapy with optional delayed arthroscopic partial meniscectomy at 24-month follow-up in young patients with isolated traumatic meniscal tears without radiographic OA.

Advancements in health informatics: finite element insights into medial open-wedge high tibial osteotomy and lateral meniscal tears

Knee medial compartment osteoarthritis is effectively treated by a medial open-wedge high tibial osteotomy (MOWHTO). The feasibility and safety of MOWHTO for mild lateral meniscal tears are unknown. This study examined the feasibility and safety of knee joint weight-bearing line ratio (WBLr) adjustment during MOWHTO with lateral meniscal injuries. We used a healthy adult male's lower extremities computed tomography scans and knee joint magnetic resonance imaging images to create a normal fine element (FE) model. Based on this model, we generated nine FE models for the MOWHTO operation (WBLr: 40-80%) and 15 models for various lateral meniscal injuries. A compressive load of 650N was applied to all cases to calculate the von Mises stress (VMS), and the intact lateral meniscus' maximal VMS at 77.5% WBLr was accepted as the corrective upper limit stress. Our experimental results show that mild lateral meniscal tears can withstand MOWHTO, while severe tears cannot. Our findings expand the use of MOWHTO and provide a theoretical direction for practical decisions in patients with lateral meniscal injuries.

Females show worse functional outcome and quality of life compared to males 2 years after meniscus surgery: Data analysis from the German Arthroscopy Registry

PURPOSE

The purpose of this study was to investigate the impact of sex on knee function, activity and quality of life following meniscus surgery using data from the German Arthroscopy Registry.

METHODS

This is a retrospective cohort study with data collected between 2017 and 2022. Patient-reported outcome measures (PROMs), namely Knee Injury and Osteoarthritis Outcome Score (KOOS), EuroQol Visual Analogue Scale (EQ Scale), and Marx Activity Rating Scale (MARS), were collected preoperatively and at 6, 12 and 24 months postoperatively. Data were analysed to examine differences between male and female patients regarding PROMs, pre-existing conditions, meniscus lesion types and surgical treatments.

RESULTS

A total of 1106 female (36.6%) and 1945 male patients (63.7%) were included. Males were significantly younger than females and had a higher body mass index. Overall, there were four times more medial meniscus lesions (MMLs) (77.5%) than lateral meniscus lesions (LMLs) (27.9%). Degenerative LMLs were more frequent in females, while traumatic LMLs were more common in males. Frequencies of traumatic and degenerative MMLs were similar among males and females. Males had higher absolute KOOS irrespective of treatment or meniscus lesion type. Meniscus repair resulted in similar improvements in ΔKOOS for both sexes, while meniscus resection exhibited higher absolute KOOS for males at each time point. Males generally had higher EQ Scale and MARS than females.

CONCLUSION

Greater improvements in knee function, activity and quality of life were observed in males. While MMLs appear to be comparable among sexes, the nature of LML differed significantly. These results may help surgeons to refine patient selection for specific treatments to improve overall clinical outcomes.

LEVEL OF EVIDENCE

Level III.

High survival rate after the combination of intrameniscal and intraarticular infiltrations of platelet-rich plasma as conservative treatment for meniscal lesions

PURPOSE

To evaluate the efficacy of applying a combination of intrameniscal and intraarticular infiltrations of Platelet-Rich Plasma (PRP) in patients with meniscal tears, analyzing its failure rate and clinical evolution, as well as factors that may influence the positive response to this treatment.

METHODS

Three hundred and ninety-two cases out of 696 met the inclusion criteria and were included in this work. Survival and patient-reported outcome measure (PROM) were collected and analyzed. Survival rate was defined as the percentage of patients who did not undergo meniscus surgery during their follow-up time. Patients were asked to complete the Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline, 6 months and 18 months. Other patient- and pathology-related variables were collected. Blood and PRP samples were randomly tested as a quality control measure. Survival and comparative statistical tests, and multivariate regression were performed for the analysis of the variables.

RESULTS

The PRP applied had a platelet concentration factor of 1.9X in respect to blood levels, with no leukocytes or erythrocytes. Thirty-eight patients required surgical intervention after treatment reaching a survival rate of 90.3% with an estimated mean survival time of 54.4 months. The type of injury (P = 0.002) and the presence of chondropathy were risk factors for surgical intervention after PRP treatment (P = 0.043). All KOOS scores showed a significant statistical increase from baseline to 6 months (N = 93) and 18 months (N = 66) (P < 0.0001). The number of cases with minimal clinically important improvement (MCII) at 6 months and 18 months post-treatment was 65 (69.9%) and 43 (65.2%), respectively.

CONCLUSION

The combination of intrameniscal and intraarticular PRP infiltrations is a valid conservative treatment for meniscal injuries avoiding the need for surgical intervention. Its efficacy is higher in horizontal tears and decreases when joint degeneration is present.

LEVEL OF EVIDENCE

Level IV.

Micro RNA in meniscal ailments: current concepts

INTRODUCTION

Micro RNAs (miRNAs) are short non-coding RNAs that act primarily in posttranscriptional gene silencing, and are attracting increasing interest in musculoskeletal conditions.

SOURCE OF DATA

Current scientific literature published in PubMed, Google Scholar, Embase and Web of Science databases.

AREAS OF AGREEMENT

Recently, the potential of miRNAs as biomarkers for diagnosis and treatment of meniscal injuries has been postulated.

AREAS OF CONTROVERSY

Evaluation of the role of miRNAs in patients with meniscal tears is still controversial.

GROWING POINTS

A systematic review was conducted to investigate the potential of miRNA in the diagnosis and management of meniscal damage.

AREAS TIMELY FOR DEVELOPING RESEARCH

Intra-articular injection of microRNA-210 in vivo may represent a potential innovative methodology for the management of meniscal injuries. Characterization of the miRNAs expression in the synovial fluid could lead to the development of better early diagnosis and management strategies for meniscal tears.

Meniscal procedures are not increased with delayed ACL reconstruction and rehabilitation: results from a randomised controlled trial

OBJECTIVE

To assess whether initial non-operative treatment of anterior cruciate ligament (ACL) ruptures with optional delayed ACL reconstruction leads to more meniscal procedures compared with early ACL reconstruction during the 2-year follow-up.

METHODS

We compared the number of meniscal procedures of 167 patients with an ACL rupture, who either received early ACL reconstruction (n=85) or rehabilitation therapy plus optional delayed ACL reconstruction (n=82), participating in the Conservative vs Operative Methods for Patients with ACL Rupture Evaluation trial. Patients were aged 18 to 65 years (mean 31.3, SD 10.5), 60% male sex (n=100). We evaluated the presence and location of meniscal tears by baseline MRI. We analysed and compared how many patients per randomisation group had a meniscal procedure during follow-up in the ACL injured knee, adjusted for sex, body mass index, age group and orthopaedic surgeon.

RESULTS

At baseline, 41% of the entire study population (69/167 patients) had a meniscal tear on MRI. During the 2-year follow-up, 25 patients randomised to early ACL reconstruction (29%, 25/85 patients) had a meniscal procedure, compared with 17 patients randomised to rehabilitation plus optional delayed reconstruction (21%, 17/82 patients) (risk ratio 0.67 with 95% CI 0.40 to 1.12, p=0.12). Of these patients who received early ACL reconstruction (n=82) and patients that received delayed ACL reconstruction (n=41), 5% of the patients had an additional isolated meniscal procedure after ACL reconstruction. In patients who received no ACL reconstruction (n=41), 10% (n=4) had an isolated surgical procedure for a meniscal tear during the 2-year follow-up period.

CONCLUSION

Initial non-surgical treatment of ACL ruptures followed by optional delayed ACL reconstruction does not lead to a higher number of meniscal procedures compared with early ACL reconstruction over a 2-year follow-up period.

TRIAL REGISTRATION NUMBER

NL 2618.

Macroscopic Synovial Inflammation Correlates with Symptoms and Cartilage Lesions in Patients Undergoing Arthroscopic Partial Meniscectomy: A Clinical Study

Background: The aim of the study was to examine the relationship among patients’ characteristics, intraoperative pathology and pre/post-operative symptoms in a cohort of patients undergoing arthroscopic partial meniscectomy for symptomatic meniscal tears. Methods: Clinical data were collected (age, sex, body mass index, time to surgery, trauma). Intraoperative cartilage pathology was assessed with Outerbridge score. Meniscal tears were graded with the ISAKOS classification. Synovial inflammation was scored using the Macro-score. Patient symptoms were assessed pre/post-operatively using the KOOS instrument. Results: In the series of 109 patients (median age 47 years), 50% of the meniscal tears were traumatic; 85% of patients showed mild to moderate synovitis; 52 (47.7%) patients had multiple cartilage defects and 31 (28.4%) exhibited a single focal chondral lesion. Outerbridge scores significantly correlated with patient age, BMI and synovial inflammation. There was a correlation between severity of chondral pathology and high-grade synovial hyperplasia. Pre-operative KOOS correlated with BMI, meniscal degenerative changes and symptom duration. Obesity, time to surgery, presence of high-grade synovial hyperplasia and high-grade cartilage lesions were independent predictors of worse post-operative pain and function. Conclusion: We demonstrated that pre-operative symptoms and post-operative outcomes correlate with synovitis severity and cartilage pathology, particularly in old and obese patients that underwent arthroscopic partial meniscectomy. Importantly, patients with a degenerative meniscal pattern and with longer time to surgery experienced more severe cartilage damage and, consequentially, pain and dysfunction. These findings are fundamental to identify patients suitable for earlier interventions.

Targeted transcriptomic analyses of RNA isolated from formalin-fixed and paraffin-embedded human menisci

Formalin-fixed and paraffin-embedded (FFPE) biospecimens are a valuable and widely-available resource for diagnostic and research applications. With biobanks of tissue samples available in many institutions, FFPE tissues could prove to be a valuable resource for translational orthopaedic research. The purpose of this study was to characterize the molecular profiles and degree of histologic degeneration on archival fragments of FFPE human menisci obtained during arthroscopic partial meniscectomy. We used FFPE menisci for multiplexed gene expression analysis using the NanoString nCounter® platform, and for histological assessment using a quantitative scoring system. In total, 17 archival specimens were utilized for integrated histologic and molecular analyses. The median patient age was 22 years (range: 14-62). We found that the genes with the highest normalized counts were those typically expressed in meniscal fibrocartilage. Gene expression differences were identified in patient cohorts based on age (≤40 years), including genes associated with the extracellular matrix and tissue repair. The majority of samples showed mild to moderate histologic degeneration. Based on these data, we conclude that FFPE human menisci can be effectively utilized for molecular evaluation following a storage time as long as 11 years. Statement of Clinical Significance: The integration of histological and transcriptomic analyses described in this study will be useful for future studies investigating the basis for biological classification of meniscus specimens in patients. Further exploration into the genes and pathways uncovered by this study may suggest targets for biomarker discovery and identify patients at greater risk for osteoarthritis once the meniscus is torn.

Histologic and molecular features in pathologic human menisci from knees with and without osteoarthritis

The objective of this study was to evaluate histologic and molecular features of meniscus degeneration in cohorts of patients with and without osteoarthritis (OA) of the knee. Menisci were obtained from patients undergoing total knee arthroplasty for OA (TKA) or arthroscopic partial meniscectomy (APM) for a torn knee meniscus. Degenerative meniscal tears were among the most common tear type in the APM group based on the pattern. Using an integrative workflow for molecular evaluation of formalin-fixed and paraffin-embedded tissues, human menisci underwent blinded histologic evaluation and NanoString gene expression analyses. Histology revealed increased proteoglycan content in TKA menisci compared to APM menisci, but otherwise no significant differences in the total pathology score or sub-scores between patients based on age or cohort. NanoString analyses revealed differential expression of genes primarily associated with the PI3K-AKT signaling pathway, cell cycle, and apoptosis. These data provide new insights into histological and molecular features of meniscus degeneration in patients with and without knee OA. Histologic assessment of menisci showed similar severity of overall degeneration between cohorts, but there were differences at the molecular level. The dysregulated pathways identified in this study could contribute to early-onset meniscus degeneration, or to a predisposition to meniscus tears and subsequent knee OA. Further studies that validate genes and pathways uncovered in this study will allow us to evaluate novel approaches to assess and treat meniscal degeneration.

Study on feasibility of the partial meniscal allograft transplantation

Since the meniscus is an important stabilizing structure of the knee joint and has a significant role in load-bearing and shock absorption, so the complete structural and functional reconstructions of the teared menisci should be done not only after partial meniscectomy but also post total meniscectomy. So far, animal experiments and good clinical practice have showed that TMAT after total meniscectomy has partially solved the problem of structural and functional reconstructions after total meniscectomy. However, partial meniscectomy will also lead to accelerated knee degeneration, and its proportion is much higher than that of patients with total meniscectomy. Herein, the feasibility of PMAT after partial meniscectomy was investigated for the first time by using the 40% posterior horn meniscectomy model of the medial meniscus in Beagle dogs, and also for the first time, TMAT group and the total meniscectomy group were used as control groups. Compared with the TMAT, the transcriptomics evaluation, scanning electron microscope observation, histological regeneration and structure, biomechanical property, inflammation environment, and the knee function post PMAT were more similar to that of normal meniscus was first reported. This study provides a PMAT scheme with clinical translational value for the complete structural and functional reconstruction of the patients with partial meniscectomy and fills the gap in the field of teared meniscus therapy on the basis of quite well clinical applications of the meniscus repair and the TMAT.

Identification and validation of pivotal genes related to age-related meniscus degeneration based on gene expression profiling analysis and in vivo and in vitro models detection

BACKGROUND

The componential and structural change in the meniscus with aging would increase the tissue vulnerability of the meniscus, which would induce meniscus tearing. Here, we investigated the molecular mechanism of age-related meniscus degeneration with gene expression profiling analysis, and validate pivotal genes in vivo and in vitro models.

METHODS

The GSE45233 dataset, including 6 elderly meniscus samples and 6 younger meniscus samples, was downloaded from the Gene Expression Omnibus (GEO) database. To screen the differential expression of mRNAs and identify the miRNAs targeting hub genes, we completed a series of bioinformatics analyses, including functional and pathway enrichment, protein-protein interaction network, hub genes screening, and construction of a lncRNA-miRNA-mRNA network. Furthermore, crucial genes were examined in human senescent menisci, mouse senescent meniscus tissues and mouse meniscus cells stimulated by IL-1β.

RESULTS

In total, the most significant 4 hub genes (RRM2, AURKB, CDK1, and TIMP1) and 5 miRNAs (hsa-miR-6810-5p, hsa-miR-4676-5p, hsa-miR-6877-5p, hsa-miR-8085, and hsa-miR-6133) that regulated such 4 hub genes, were finally identified. Moreover, these hub genes were decreased in meniscus cells in vitro and meniscus tissues in vivo, which indicated that hub genes were related to meniscus senescence and could serve as potential biomarkers for age-related meniscus tearing.

CONCLUSIONS

In short, the integrated analysis of gene expression profile, co-expression network, and models detection identified pivotal genes, which elucidated the possible molecular basis underlying the senescence meniscus and also provided prognosis clues for early-onset age-related meniscus tearing.

Accuracy of standard magnetic resonance imaging sequences for meniscal and chondral lesions versus knee arthroscopy. A prospective case-controlled study of 719 cases

BACKGROUND

Magnetic resonance imaging (MRI) is commonly used for diagnosis and as a research tool, but its accuracy is questionable. The goal of this study was to compare the accuracy of knee MRI with clinical assessment for diagnosing meniscal tears, and to determine the accuracy of MRI for grading chondral lesions, relative to arthroscopy.

METHODS

Physically active patients presenting with mechanical symptoms warranting a knee arthroscopy and satisfying the inclusion criteria, had both a knee arthroscopy and MRI performed. Arthroscopic findings were compared with those of MRI, using the International Chondral Research Society grading for chondral damage, and the presence or absence of a meniscal tear.

RESULTS

A total of 719 patients were recruited over a period of 6.5 years, average age 52 years (standard deviation, SD 5.2), male:female = 493:226. Kappa scores with standard errors (SE) for agreement between MRI and knee arthroscopy were 0.41 (SE 0.1) for medial meniscal tears, and 0.44 (SE 0.1) for lateral meniscal tears. For the grade of chondral damage, the Kappa scores with SE values were 0.09 (0.1), 0.17 (0.1), and 0.22 (0.07) for anterior, medial and lateral compartments, respectively. Using areas under the receiver operating characteristic curves, we found clinical assessment was more accurate than MRI for diagnosis of lateral meniscal tears (P < 0.001), and of similar accuracy for the diagnosis of medial meniscal tears (P = 0.12).

CONCLUSIONS

MRI has relatively poor correlation with arthroscopic findings for grading the chondral damage and was less accurate than clinical assessment for the diagnosis of lateral meniscal tears.

Meniscal tears are more common than previously identified, however, less than a quarter of people with a tear undergo arthroscopy

PURPOSE

The management of meniscal tears is a widely researched and evolving field. Previous studies reporting the incidence of meniscal tears are outdated and not representative of current practice. The aim of this study was to report the current incidence of MRI confirmed meniscal tears in patients with a symptomatic knee and the current intervention rate in a large NHS trust.

METHODS

Radiology reports from 13,358 consecutive magnetic resonance imaging scans between 2015 and 2017, performed at a large UK hospital serving a population of 470,000, were assessed to identify patients with meniscal tears. The hospital database was interrogated to explore the subsequent treatment undertaken by the patient. A linear regression model was used to identify if any factors predicted subsequent arthroscopy.

RESULTS

1737 patients with isolated meniscal tears were identified in patients undergoing an MRI for knee pain, suggesting a rate of 222 MRI confirmed tears per 100,000 of the population aged 18 to 55 years old. 47% attended outpatient appointments and 22% underwent arthroscopy. Root tears [odds ratio (95% CI) 2.24 (1.0, 4.49); p = 0.049] and bucket handle tears were significantly associated with subsequent surgery, with no difference between the other types of tears. The presence of chondral changes did not significantly affect the rate of surgery [0.81 (0.60, 1.08); n.s].

CONCLUSION

Meniscal tears were found to be more common than previously described. However, less than half present to secondary care and only 22% undergo arthroscopy. These findings should inform future study design and recruitment strategies. In agreement with previous literature, bucket handle tears and root tears were significant predictors of subsequent surgery.

LEVEL OF EVIDENCE

III.