Clinical Outcomes of Different Management Techniques for Medial Meniscal Type 3 Ramp Lesions in Anterior Cruciate Ligament Reconstruction: A Comparative Analysis Between All-inside Repair, Suture Hook Repair, and Lesions Left In Situ.

BACKGROUND: There is ongoing debate about the best way to manage ramp lesions at the time of anterior cruciate ligament (ACL) reconstruction (ACLR). Type 3 lesions are not visible by the transnotch approach without superior debridement, making the management debate even more problematic. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the rate of secondary surgical interventions according to the management method of a type 3 ramp lesion concomitant with primary ACLR. The hypothesis was that the rate of secondary ACL or meniscal interventions would be higher in patients who underwent all-inside repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective analysis of all patients who underwent primary ACLR with a type 3 ramp lesion between January 2012 and May 2020, regardless of the treatment method, was performed. The main criterion analyzed in this cohort was a secondary surgical intervention, defined as revision ACLR or a reintervention of the repaired meniscus. A survivorship analysis was performed to evaluate secondary surgical interventions in 3 groups: all-inside repair, suture hook repair, and left in situ. The following data were collected preoperatively and at the last follow-up: patient characteristics, time to surgery, side-to-side difference in laxity, pivot shift, Lysholm score, subjective International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Tegner score, and meniscal repair failure rate. RESULTS: A total of 113 patients who underwent type 3 ramp lesion repair concomitant with ACLR were included: 52 (46.0%) in the all-inside repair group, 23 (20.4%) in the suture hook repair group, and 38 (33.6%) in the lesion left in situ group. There were 17 patients (15.0%) who underwent a secondary intervention because of ACL graft failure (n = 6) or meniscal repair failure (n = 15 [4 of whom underwent a concomitant ACL reintervention]). Overall, 62 patients (54.9%) underwent combined ACLR and anterolateral ligament reconstruction, while 51 patients (45.1%) underwent isolated ACLR. In the adjusted Cox model, the type of meniscal repair was not statistically significantly associated with secondary surgical interventions. The only risk factor for secondary surgical interventions in this cohort was isolated ACLR (hazard ratio, 8.077; P = .007). CONCLUSION: The rates of secondary surgical interventions after medial meniscal type 3 ramp lesion repair concomitant with ACLR were similar regardless of the management method of the meniscal lesion. Despite not being associated with meniscal treatment, this rate was 8 times higher for patients who underwent isolated ACLR in this cohort; this is probably because of the protection that lateral extra-articular procedures provide to the ACL graft.

Sakuranetin reduces inflammation and chondrocyte dysfunction in osteoarthritis by inhibiting the PI3K/AKT/NF-κB pathway.

Osteoarthritis (OA) is a prevalent degenerative disease that impairs limb function, and its pathogenesis is closely related to inflammation. Sakuranetin (SK) is a cherry flavonoid phytoalexin with potent anti-inflammatory, anti-oxidant, and ant-ifungal properties. In recent studies, flavonoid and phytoalexin-related medicines have shown promise in the treatment of OA. However, the effects of SK on chondrocyte inflammation and the chondrogenesis process have remained unexplored, as have its functions in OA treatment. This study sought to confirm the therapeutic effects of SK in the OA rat model and reveal the potential mechanisms for protecting chondrocytes. The relevant mechanisms of SK were analyzed by network pharmacology analysis. Chondrocytes were subjected to IL-1ß intervention to simulate an inflammatory environment and received SK treatment. Then, anabolism, catabolism, and inflammatory markers were detected by western blot, qPCR, elisa, and immunofluorescence. Chondrogenic ability was evaluated by micromass and 3D culture assays. The rats were treated with destabilization of the medial meniscus (DMM) surgery to establish an OA model and SK intra-articular injections subsequently. Histological staining, immunohistochemistry, and micro-CT were performed to analyze the structural and morphological changes of cartilage and subchondral bone. In chondrocytes, IL-1ß treatment reduced chondrogenic ability, promoted catabolism, and exacerbated inflammation by triggering the PI3K/AKT/NF-κB pathway, whereas SK treatment partially rescued these negative effects. In vivo, SK treatment effectively alleviated the degeneration of cartilage and subchondral bone, thereby delaying the progression of OA. In summary, SK alleviates chondrocyte inflammation and promotes chondrogenesis by inhibiting the PI3K/AKT/NF-κB pathway, thereby improving OA progression.

Mid-Term Clinical and Radiological Outcomes of Lateral Meniscal Allograft Transplantation with Suture-Only Fixation Plus Capsulodesis.

Meniscal allograft transplantation (MAT) is an effective reconstructive procedure for treating a symptomatic postmeniscectomy syndrome. It consists of replacing the lost meniscal tissue aiming to improve the clinical outcomes and prevent progressive deterioration of the joint. The aim of this study was to evaluate meniscal graft survivorship and report on the radiographic (in terms of graft extrusion and joint space width and alignment) and the functional results through a midterm follow-up of lateral MAT performed with a soft tissue fixation technique after capsulodesis. In total, 23 patients who underwent lateral MAT as a single procedure were included. The Knee injury and Osteoarthritis Outcome Score, Lysholm, Tegner, and visual analog scale scales were used for patient assessment. Magnetic resonance imaging and a complete radiographic protocol were conducted to determine the degree of meniscal extrusion and the changes in the degree of osteoarthritis and coronal alignment. Assessments were performed after 2 and 7 years of follow-up. A significant improvement in all the scores, relative to preoperative values, was found after 7 years of follow-up. This improvement remained consistent throughout the first and second follow-up periods. A mean absolute extrusion of 2.2 mm ± 1.6 and an extrusion percentage of 28.0% ± 11.43 were found, with no significant differences throughout the follow-up periods. There was no statistically significant difference in terms of the frontal mechanical axis and joint space narrowing between the preoperative value and at the first and second follow-up periods. A survival rate of 85.7% was found after 7 years of follow-up. Capsulodesis results in a low degree of meniscal extrusion in isolated lateral MAT fixed with a suture-only technique, which is maintained after 7 years of follow-up, with a high graft survival index (>85%) and satisfactory results on the functional scales.

Medial meniscus extrusion is invariably observed and consistent with tibial osteophyte width in elderly populations: The Bunkyo Health Study.

We reported that the full-length width of medial tibial osteophytes comprising cartilage and bone parts correlates with medial meniscus extrusion (MME) in early-stage knee osteoarthritis (OA). However, no data exist on the prevalence of MME and its relationship with osteophytes in the elderly population. 1191 elderly individuals (females 57%; 72.9 years old on average) in the Bunkyo Health Study underwent standing plain radiograph and proton density-weighted MRI on knee joints. MRI-detected OA changes were evaluated according to the Whole-Organ Magnetic Resonance Imaging Score. A new method of assessing the cartilage and bone parts of osteophytes was developed using pseudo-coloring images of proton density-weighted fat-suppressed MRI. Most subjects showed Kellgren-Lawrence grade 1 or 2 radiographic medial knee OA (88.1%), MME (98.7%, 3.90 ± 2.01 mm), and medial tibial osteophytes (99.3%, 3.27 ± 1.50 mm). Regarding OA changes, MME was closely associated with the full-length width of medial tibial osteophytes (ß = 1.114; 95% CI 1.069-1.159; p < 0.001) in line with osteophyte width (intraclass correlation coefficient, 0.804; 95% CI 0.783-0.823). Our data revealed that MME and medial tibial osteophytes are observed in the elderly and demonstrate that the degree of MME is consistent with the full-length width of medial tibial osteophytes, suggesting that osteophytes might be implicated in MME.

Effect of intra-articular injection of a hyaluronic acid-alendronate conjugate on post-traumatic osteoarthritis induced by destabilization of the medial meniscus in rats.

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by pain and cartilage damage. Intra-articular (i.a) viscosupplementation with hyaluronic acid (HA) is frequently used for the management of OA. Preclinical studies have reported that bisphosphonates (BPs) may have a therapeutic potential to slow down or reverse the progression of OA. Among these, alendronate (ALN) has demonstrated chondroprotective effects in both in vitro and vivo experiments. This study evaluated the effects of a novel alendronate-hyaluronic acid (ALN-HA) conjugate on an OA in vivo model induced by medial meniscus destabilization (DMM). DMM surgery was performed on the knees of Sprague Dawley rats that received, after four weeks, one intra-articular (i.a.) injection of: (1) ALN-HA; (2) HA; (3) sodium chloride (NaCl). Sham-operated rats were used as control. Allodynia was assessed by Von Frey test. Joint degeneration was evaluated eight weeks after treatment by micro-computed tomography (micro-CT), histology, and immunohistochemistry. Collagen cross-linked C-telopeptides (CTX-I and CTX-II) serum levels were determined by ELISA. Paw withdrawal threshold increased in ALN-HA group when compared to rats treated with NaCl or HA. Micro-CT did not show differences between ALN-HA, HA and NaCl groups. ALN-HA injection produced significant improvements in articular cartilage degeneration showing an OARSI score lower than those of HA and NaCl, and reduced matrix metalloproteinase (MMP)-13, MMP-3, interleukin-6, vascular endothelial growth factor and Caspase-3 expression. CTX-I was reduced after ALN-HA treatment when compared to NaCl. Our results indicate that i.a. use of ALN after conjugation with HA limits OA development and progression in the rat DMM model, and may lead to the development of novel therapeutic strategies in OA management.

Combined Medial And Lateral Bucket Handle Meniscus Tears With Associated Complete Anterior Cruciate Ligament Tear: A Case Report.

The majority of meniscal tears in bucket handles are associated with anterior cruciate ligament (ACL) impairment. Its a rare condition which is rarely encountered when the meniscus has a bucket handle on both sides of the compartment. Here we present the case of a 28-year- old male cricket player with a total ACL rupture, a double Posterior Cruciate ligament (PCL) sign on MRI (Magnetic Resonance Imaging), an uncommon occurrence of a complex bucket handle rupture of the medial meniscus with a double PCL sign. It was a complete ACL tear and displaced bucket handle medial meniscus that was also visible on the magnetic resonance imaging. In this report, double PCL sign was shown on MRI and that was confirmed during the arthroscopic procedure.

Meniscal extrusion in knees with and without osteoarticular pathology: A systematic review of normative values and cut-offs for diagnostic criteria.

BACKGROUND: Meniscus extrusion is crucial for the diagnosis and treatment of meniscal injury, but the literature on this topic has not yet been systematized. The purpose of this systematic review was to compare diagnostic methods and summarize the data of medial and lateral meniscal extrusion in knees with and without osteoarticular pathology. METHODS: This systematic review was conducted according to the PRISMA 2020 statement. Searches were conducted on PubMed, EMBASE and Cochrane databases to identify studies that measured meniscal extrusion using magnetic resonance imaging (MRI) or ultrasound (US). Meniscal extrusion data was summarized as weighted mean for medial and lateral meniscus, and stratified according to the method of measurement (MRI or US) and presence of knee osteoarticular pathology. RESULTS: A total of 26 studies were included in this review. Weighted mean values of meniscal extrusion were always higher for the medial than the lateral meniscus, regardless of the method of measurement. The medial meniscus extrusion was always higher in knees with osteoarticular pathology than those without. For the lateral meniscus extrusion, the mean values were higher in those knees without osteoarticular pathology. When classifying pathological meniscal extrusion with pre-defined cut-off values, the higher the cut-off used, the lower the percentage of knees classified as pathological meniscal extrusion. CONCLUSIONS: The medial meniscus presents on mean higher extrusion and extrusion is higher in knees with osteoarticular pathology. Based on summary data, the most suitable cut-offs for pathological meniscal extrusion for both MRI and US seem to fall within >2 and >3 mm.

Relationship Between Age and Pathology With Treatment of Pediatric and Adolescent Discoid Lateral Meniscus: A Report From the SCORE Multicenter Database.

BACKGROUND: Surgical treatment options of discoid lateral meniscus in pediatric patients consist of saucerization with or without meniscal repair, meniscocapular stabilization, and, less often, subtotal meniscectomy. PURPOSE: To describe a large, prospectively collected multicenter cohort of discoid menisci undergoing surgical intervention, and further investigate corresponding treatment of discoid menisci. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A multicenter quality improvement registry (16 institutions, 26 surgeons), Sports Cohort Outcomes Registry, was queried. Patient characteristics, discoid type, presence and type of intrasubstance meniscal tear, peripheral rim instability, repair technique, and partial meniscectomy/debridement beyond saucerization were reviewed. Discoid meniscus characteristics were compared between age groups (<14 and >14 years old), based on receiver operating characteristic curve, and discoid morphology (complete and incomplete). RESULTS: In total, 274 patients were identified (mean age, 12.4 years; range, 3-18 years), of whom 55.6% had complete discoid. Meniscal repairs were performed in 55.1% of patients. Overall, 48.5% of patients had rim instability and 36.8% had >1 location of peripheral rim instability. Of the patients, 21.5% underwent meniscal debridement beyond saucerization, with 8.4% undergoing a subtotal meniscectomy. Patients <14 years of age were more likely to have a complete discoid meniscus (P < .001), peripheral rim instability (P = .005), and longitudinal tears (P = .015) and require a meniscal repair (P < .001). Patients ≥14 years of age were more likely to have a radial/oblique tear (P = .015) and require additional debridement beyond the physiologic rim (P = .003). Overall, 70% of patients <14 years of age were found to have a complete discoid meniscus necessitating saucerization, and >50% in this young age group required peripheral stabilization/repair. CONCLUSION: To preserve physiological "normal" meniscus, a repair may be indicated in >50% of patients <14 years of age but occurred in <50% of those >14 years. Additional resection beyond the physiological rim may be needed in 15% of younger patients and 30% of those aged >14 years.

Impact of lateral meniscus injury detected by preoperative magnetic resonance imaging on midterm results after unicompartmental knee arthroplasty.

BACKGROUND: The significance of lateral meniscus injury and its impact on success rates with medial unicompartmental knee arthroplasty (UKA) is still debated among scholars. This study aims to investigate whether preoperative magnetic resonance imaging (MRI) findings of lateral meniscus injury influence midterm outcomes following UKA. METHODS: This study recruited 104 patients who underwent medial mobile-bearing UKA. Based on the extent of lateral meniscus injury indicated by the preoperative MRI and Stoller's classification system, patients were divided into two groups: the normal group (grade 0), and the lateral meniscus injury group (grade 3). Further, preoperative demographic and clinical outcome data (Hospital for Special Surgery score, lateral knee pain, squatting, and knee extension ability) were compared at least 2 years postoperatively. RESULTS: No statistically significant difference in knee function or clinical outcome was found between the normal group (n = 59) and the lateral meniscus injury group (n = 45). During the 39.2 months (range: 24-64 months), no patient required any reoperation or revision procedures. CONCLUSION: In summary, the presence of lateral meniscus injury as determined by preoperative MRI does not affect the midterm results after UKA. Without additional treatment for lateral meniscus injury, UKA can yield desired outcomes regardless of the presence of lateral meniscus injury on preoperative MRI.

Meniscal Fibrocartilage Repair Based on Developmental Characteristics: A Proof-of-Concept Study.

BACKGROUND: Unlike the adult meniscus, the fetal meniscus possesses robust healing capacity. The dense and stiff matrix of the adult meniscus provides a biophysical barrier for cell migration, which is not present in the fetal meniscus. Inspired by developmental characteristics, modifying the matrix of the adult meniscus into a fetal-like, loose and soft microenvironment holds opportunity to facilitate repair, especially in the avascular zone. HYPOTHESIS: Modifying the dense and stiff matrix of the adult meniscus into a fetal-like, loose and soft microenvironment could enhance cell migration to the tear interface and subsequent robust healing capacity. STUDY DESIGN: Controlled laboratory study. METHODS: Fresh porcine menisci were treated with hyaluronidase or collagenase. The density and arrangement of collagen fibers were assessed. The degradation of proteoglycans and collagen was evaluated histologically. Cell migration within the meniscus or the infiltration of exogenous cells into the meniscus was examined. Dendritic silica nanoparticles with relatively large pores were used to encapsulate hyaluronidase for rapid release. Mesoporous silica nanoparticles with relatively small pores were used to encapsulate transforming growth factor-beta 3 (TGF-ß3) for slow release. A total of 24 mature male rabbits were included. A longitudinal vertical tear (0.5 cm in length) was prepared in the avascular zone of the medial meniscus. The tear was repaired with suture, repaired with suture in addition to blank silica nanoparticles, or repaired with suture in addition to silica nanoparticles releasing hyaluronidase and TGF-ß3. Animals were sacrificed at 12 months postoperatively. Meniscal repair was evaluated macroscopically and histologically. RESULTS: The gaps between collagen bundles increased after hyaluronidase treatment, while collagenase treatment resulted in collagen disruption. Proteoglycans degraded after hyaluronidase treatment in a dose-dependent manner, but collagen integrity was maintained. Hyaluronidase treatment enhanced the migration and infiltration of cells within meniscal tissue. Last, the application of fibrin gel and the delivery system of silica nanoparticles encapsulating hyaluronidase and TGF-ß3 enhanced meniscal repair responses in an orthotopic longitudinal vertical tear model. CONCLUSION: The gradient release of hyaluronidase and TGF-ß3 removed biophysical barriers for cell migration, creating a fetal-like, loose and soft microenvironment, and enhanced the fibrochondrogenic phenotype of reparative cells, facilitating the synthesis of matrix and tissue integration. CLINICAL RELEVANCE: Modifying the adult matrix into a fetal-like, loose and soft microenvironment via the local gradient release of hyaluronidase and TGF-ß3 enhanced the healing capacity of the meniscus.

Factors associated with meniscus volume in knees free of degenerative features.

OBJECTIVES: To explore factors that were associated with meniscus volume in knees free of radiographic osteoarthritis (OA) features and symptoms of OA. METHODS: In the third Rotterdam Study cohort, clinical, radiographic, and magnetic resonance data were obtained at baseline (BL) and after 5 years of follow-up. Meniscus volumes and their change over time were calculated after semi-automatic segmentation on Magnetic Resonance Imaging. Knees with radiographic OA features (Kellgren and Lawrence>0) or clinical diagnosis of OA (American College of Rheumatology) at BL were excluded. Ten OA risk factors were adjusted in the multivariable analysis (generalized estimating equations), treating two knees within subjects as repeated measurements. RESULTS: From 1065 knees (570 subjects), the average (standard deviation) age and Body mass index (BMI) of included subjects were 54.3 (3.7) years and 26.5 (4.4) kg/m2. At BL, nine factors (varus alignment, higher BMI, meniscus pathologies, meniscus extrusion, cartilage lesions, injury, greater physical activity level, quadriceps muscle strength, and higher age) were significantly associated with greater meniscus volume. Five factors (injury, meniscus pathologies, meniscus extrusion, higher age, and change of BMI) were significantly associated with meniscus volume loss. CONCLUSIONS: Modifiable factors (varus alignment, BMI, physical activity level, and quadriceps muscle strength) and non-modifiable factors (higher age, injury, meniscus pathologies, meniscus extrusion, and cartilage lesions) were all associated with meniscus volume or meniscus volume loss over time.

Abnormalities of the pericruciate fat pad: Correlations with the location and severity of chondral lesions of the knee.

PURPOSE: The aim of this study was to evaluate the relationship between the grade of signal change of the pericruciate fat pad (PCFP) and the location and severity of cartilage alterations in the knee on magnetic resonance imaging (MRI). MATERIALS AND METHODS: This retrospective study included 234 patients (M:F = 96:138, mean: 51 years) who underwent knee MRI. Two experienced musculoskeletal radiologists assessed any PCFP alterations (as grades 0-3) and chondral lesions using the modified Outerbridge grade (as grades 0-4). Bone marrow lesions (BMLs), meniscal status, anterior cruciate ligament alterations, and effusion-synovitis were also evaluated on the MRI. The relationships between PCFP alteration and MR findings (including the grade of chondral lesion) were evaluated. RESULTS: Signal changes in the PCFP were detected in 150 cases by Reader 1 (grade 0, 67 cases; grade 1, 53 cases; grade 2, 21 cases; grade 3, 9 cases) and in 154 cases by Reader 2 (grade 0, 59 cases; grade 1, 61 cases; grade 2, 24 cases; grade 3, 10 cases). The grade of PCFP signal change was statistically significantly correlated with the grade of the chondral lesion of the medial femoral condyle (MFC) (p = 0.029 and p = 0.003, respectively) and the medial tibial plateau (MTP) (p = 0.045, p = 0.002, Readers 1 and 2, respectively). The grade of PCFP signal change was significantly correlated with the grade of the BMLs of the MFC, MTP, and lateral femoral condyle (p < 0.05) for both readers. PCFP alteration was related to effusion-synovitis and tears of the medial meniscus. CONCLUSIONS: The grade of PCFP signal change was correlated with the severity of the cartilage alteration in the medial compartment of the knee joint and was also correlated with BMLs in the medial compartment, medial meniscal tears, and synovitis. Therefore, signal change in the PFCP seen on MRI can be an additional clue of the presence of osteoarthritis in the knee, particularly in the medial compartment.

An in vitro and in vivo study: Valencene protects cartilage and alleviates the progression of osteoarthritis by anti-oxidative stress and anti-inflammatory effects.

BACKGROUND: Osteoarthritis (OA) is a heterogeneous disease involving the whole joint. The pathogenesis involves oxidative stress levels and chronic inflammation, and Valencene (VA) has excellent anti-inflammatory and antioxidant stress abilities. PURPOSE: The objective was to study the effects of VA therapy on combating oxidative stress and to evaluate the protective effect of chondrocytes to alleviate the progression of OA. METHODS: C57BL6J mouse chondrocytes were used as the primary cells in this study. Mouse chondrocytes were stimulated with IL-1ß, and VA was administered in different concentrations. Reactive oxygen species (ROS) assay kits, western blotting, cellular immunofluorescence, and scanning microscopy were used to evaluate VA's antioxidant stress mechanism, anti-inflammatory effect, and cartilage protective ability. The mouse arthritis model constructed by destabilization of medial meniscus (DMM) was observed by micro-CT scan and histology after different treatments. RESULTS: We found that VA can reverse the rise of ROS under IL-1ß, the degeneration of the cartilage extracellular matrix, and the production of inflammatory mediators. In terms of mechanism, VA activated NRF2/HO-1/NQO1 pathway, thus enhancing ROS clearance. The phosphorylation of IκBα is inhibited, which further reduces the downstream phosphorylation of P65 in nuclear factor-κB (NF-κB) signaling. In addition, VA inhibited mitogen-activated protein kinase (MAPK) signaling molecules P-JNK, P-ERK, and P-P38, inhibiting the production of inflammatory mediators and thus inhibiting Aggrecan and Collagen Type II （COL2）degeneration. In vivo, VA reduced DMM-induced osteophytes and spurs, suppressed subchondral bone destruction, and reduced articular cartilage erosion. CONCLUSION: Our study demonstrated that VA is an effective candidate for OA treatment.

The meniscal extrusion index is a reliable indirect sign of different meniscal lesion patterns: a classification based on percentage of meniscal extrusion.

PURPOSE: This study's goal is to propose a straightforward classification system based on the MEI (Meniscal Extrusion Index), a measure of meniscal extrusion, that relates to various meniscal lesion patterns and has clinical and biomechanical significance. The study's secondary goal is to determine whether the standard 3 mm meniscal extrusion parameter still has value by correlating the MEI with it. METHODS: 1350 knee MRIs that were performed over the course of 2 years made up the study cohort. Following the application of inclusion and exclusion criteria, 200 of those patients were qualified to participate in the study. All the measurements examined for this study underwent an interobserver reliability test. RESULTS: In the 1350 MRIs that were examined for this study, meniscal extrusion of any grade was present 18.9% of the time. The use of the MEI revealed three groups of patients: those with a MEI < 20%, who are likely para-physiological; those with a MEY between 20% and 40%, who are in a grey area; and those with a MEY > 40%, who have lesions that are impairing the proper meniscal function. According to the authors' findings, the percentage of meniscal extrusion did not correlate with the finite number (3 mm), making the 3 mm parameter an unreliable evaluation method. CONCLUSIONS: This study is clinically relevant, because it proposes a simple and reproducible classification of meniscal extrusion that may aid in evaluating the severity of an extrusion and help in the diagnosis of lesions that might be difficult to identify on MRI. LEVEL OF EVIDENCE: Level IV.

Lateral meniscus with tears or with histologic calcification does not increase the risk of lateral osteoarthritis after medial unicompartmental arthroplasty.

PURPOSE: Meniscal tears or histological meniscal calcifications (in the absence of radiological chondrocalcinosis) are frequent in osteoarthritis. Whether lateral meniscal lesions influence clinical outcomes after medial unicompartmental knee arthroplasty (UKA) is unknown. METHODS: We analyzed 130 patients (130 knees) with medial unicompartmental knee arthroplasties between 2005 and 2015. These 130 knees had full articular cartilage thickness in the lateral compartment and no radiological chondrocalcinosis on preoperative radiographs. The lateral meniscus was analyzed with preoperative MRI and a biopsy of the anterior horn at the time of surgery. Synovial fluid was collected and analyzed for calcium pyrophosphate dihydrate crystal deposition (CPPD crystals). Lateral meniscal tears were untreated when detected on MRI or during surgery, with the hypothesis that these tears on the opposite compartment would remain asymptomatic in medial UKA. At average 10-year follow-up, patients were evaluated with clinical and radiographic outcome, with a focus on the risk of joint space narrowing of the lateral femorotibial compartment. RESULTS: CPPD crystals were present in the synovial fluid of 70 knees. Lateral meniscal tears were seen on MRI in 34 (49%) normal meniscuses of the 60 knees without CPPD crystals and in six other knees without histological meniscal calcification despite CPPD crystals. Histological calcification was present on 61 lateral meniscuses with 53 meniscal tears. The results showed no significant differences in the clinical outcomes between knees with lateral meniscal tears or lateral meniscal histological chondrocalcinosis or both lesions and those without these conditions. Additionally, radiographic progression of osteoarthritis in the opposite femorotibial compartment of the knee was not more frequent in patients with these meniscal issues. The ten year cumulative survival rates, measured by the need for total knee arthroplasty, were 91% for knees without meniscal lesions and 92% for knees with these lesions. CONCLUSION: On this basis, treatment of meniscal tears of the lateral compartment and routine aspiration of the knee to assess for birefringent crystals in the planning of medial UKA do not appear necessary.

Orientin inhibits inflammation in chondrocytes and attenuates osteoarthritis through Nrf2/NF-κB and SIRT6/NF-κB pathway.

Effects of Orientin on murine chondrocytes treated with interleukin-1ß (IL-1ß) were evaluated using qPCR, western blot analysis, ELISA, and immunofluorescent staining in vitro. In vivo, We established a standard OA model by performing the destabilized medial meniscus (DMM) surgery on C57BL/6 mice, and assessed healing effect of Orientin by X-ray imaging, histopathological analysis, immunohistochemical staining. Osteoarthritis (OA) is the most common form of degenerative joint disease in clinic and the chondrocyte inflammation plays the most important role in OA development. The natural flavonoid compound (Orientin) has anti-inflammatory bioactive properties in the treatment of various diseases. But studies have not explored whether Orientin modulates OA progression. In this study, a significant suppression in IL-1ß-mediated pro-inflammatory mediators and the degradation of cartilage extracellular matrix (ECM) was observed in vitro through qPCR, western blot analysis, ELISA, and immunofluorescent staining after the treatment with Orientin. In addition, Orientin abrogated DMM surgery induced cartilage degradation in mice, which was assessed by X-ray imaging, histopathological analysis, immunohistochemical staining. Mechanistic studies showed that Orientin suppressed OA development by downregulating activation of NF-κB by activating Nrf2/HO-1 axis and SIRT6 signaling pathway. These results provide evidence that Orientin serves as a potentially viable compound for the treatment of OA.

A human meniscus explant model for studying early events in osteoarthritis development by proteomics.

Degenerative meniscus lesions have been associated with both osteoarthritis etiology and its progression. We, therefore, sought to establish a human meniscus ex vivo model to study the meniscal response to cytokine treatment using a proteomics approach. Lateral menisci were obtained from five knee-healthy donors. The meniscal body was cut into vertical slices and further divided into an inner (avascular) and outer region. Explants were either left untreated (controls) or stimulated with cytokines. Medium changes were conducted every 3 days up to Day 21 and liquid chromatography-mass spectrometry was performed at all the time points for the identification and quantification of proteins. Mixed-effect linear regression models were used for statistical analysis to estimate the effect of treatments versus control on protein abundance. Treatment by IL1ß increased release of cytokines such as interleukins, chemokines, and matrix metalloproteinases but a limited catabolic effect in healthy human menisci explants. Further, we observed an increased release of matrix proteins (collagens, integrins, prolargin, tenascin) in response to oncostatin M (OSM) + tumor necrosis factor (TNF) and TNF+interleukin-6 (IL6) + sIL6R treatments, and analysis of semitryptic peptides provided additional evidence of increased catabolic effects in response to these treatments. The induced activation of catabolic processes may play a role in osteoarthritis development.

Dynamic ultrasound reveals the specific behavior of the medial meniscus extrusion in patients with knee osteoarthritis.

BACKGROUND: In the dynamic condition, knee osteoarthritis (OA) usually presents with pain. In the weight-bearing condition, a medial meniscus extrusion (MME) may cause severe symptoms and pathological progression. However, the correlation between a dynamic MME and pain has not been elucidated. Now, an MME can be evaluated under dynamic conditions and reflect the characteristics of symptomatic knee OA. This study investigated MMEs during walking and their correlation with knee pain. METHODS: Thirty-two symptomatic patients with knee OA (mean age, 60.5 ± 9.9 years) were enrolled in this study. The medial meniscus was evaluated using ultrasonograms during walking, and in the static supine and unipedal standing positions, as dynamic and static conditions, respectively. The ΔMME (the difference between the maximum and minimum MMEs) was obtained in each condition. The intensity of the knee pain during walking was measured by the visual analog scale (VAS). RESULTS: The ΔMME in the dynamic condition was significantly higher than that in the static condition (P < 0.01). There was a significant correlation between VAS and ΔMME only in the dynamic condition. CONCLUSIONS: The dynamic evaluation is a valid tool for understanding the mechanisms of knee pain and the behavior of the medial meniscus in symptomatic knee OA.

Radiographic OA, bone marrow lesions, higher body mass index and medial meniscal root tears are significantly associated with medial meniscus extrusion with OA or medial meniscal tears: a systematic review and meta-analysis.

PURPOSE: Medial meniscus extrusion (MME) refers to the protrusion of the medial meniscus beyond the tibial edge by more than 3 mm, leading to a deficiency of the hoop strain. MME commonly occurs in conjunction with osteoarthritis (OA) or medial meniscal tears (MMT). However, factors associated with concomitant MME in patients with OA or MMT have not been systematically reviewed. This study aims to perform a systematic review and meta-analysis to identify factors associated with concomitant MME in OA or MMT. METHODS: The systematic review of the literature was performed according to PRISMA. A literature search was conducted in 4 databases. All original human studies that reported the available evidence on factors associated with concomitant MME in patients with OA or MMT were included. Pooled binary variables were analyzed by odds ratios (OR) and 95% CIs, and pooled continuous variables were evaluated by mean difference (MD) and 95% CIs. RESULTS: Ten studies on OA (5993 patients) and eight studies on MMT (872 patients) met the inclusion criteria. The overall pooled incidence of MME was 43% (95% CI, 37-50%) for OA, 61% (95% CI 43-77%) for MMT, and 85% (95% CI 72-94%) for medial meniscal root tears (MMRT). For the population with OA, Factors significantly associated with MME included radiographic OA [OR 4.24; 95% CI 3.07-5.84; P < 0.0001], bone marrow lesions [OR, 3.35; 95% CI 1.61-6.99; P = 0.0013], cartilage damage [OR, 3.25; 95% CI 1.60-6.61; P = 0.0011], and higher body mass index (BMI) [MD, 1.81; 95% CI 1.15-2.48; P < 0.0001]. Factors strongly associated with increased risk of MME for MMT included medial meniscal root [OR, 8.39; 95% CI 2.84-24.82; P < 0.0001] and radial tears [OR, 2.64; 95% CI 1.18-5.92; P < 0.0001]. CONCLUSION: Radiographic OA, bone marrow lesions, cartilage damage, and higher BMI were significantly associated with concomitant MME with OA. Furthermore, medial meniscal root and radial tears were significantly associated with an increased risk of MME in patients with MMT. LEVEL OF EVIDENCE: IV.

Meniscal degeneration is prognostic of destabilzing meniscal tear and accelerated knee osteoarthritis: Data from the Osteoarthritis Initiative.

The objective of this study was to assess the prognostic potential of magnetic resonance (MR)-detected meniscal degeneration in relation to incident destabilizing meniscal tears (radial, complex, root, or macerated) or accelerated knee osteoarthritis (AKOA). We used existing MR data from a case-control study of three groups from the Osteoarthritis Initiative without radiographic KOA at baseline: AKOA, typical KOA, and no KOA. From these groups, we included people without medial and lateral meniscal tear at baseline (n = 226) and 48-month meniscal data (n = 221). Intermediate-weighted fat-suppressed MR images annually from baseline to the 48-month visit were graded using a semiquantitative meniscal tear classification criterion. Incident destabilizing meniscal tear was defined as progressing from an intact meniscus to a destabilizing tear by the 48-month visit. We used two logistic regression models to assess whether: (1) presence of medial meniscal degeneration was associated with an incident medial destabilizing meniscal tear, and (2) presence of meniscal degeneration in either meniscus was associated with incident AKOA over the next 4 years. People with the presence of a medial meniscal degeneration had three times the odds of developing an incident destabilizing medial meniscal tear within 4 years compared with a person without medial meniscus degeneration (odds ratio [OR]: 3.03; 95% confidence interval [CI]: 1.40-6.59). People with meniscal degeneration had five times the odds of developing incident AKOA within 4 years compared with a person without meniscal degeneration in either meniscus (OR: 5.04; 95% CI: 2.57-9.89). Meniscal degeneration on MR is clinically meaningful as it relates to future poor outcomes.