Medial Meniscus Research Articles

Targeting long non-coding RNA H19 in Subchondral Bone Osteocytes Alleviates Cartilage Degradation in Osteoarthritis.

Emerging evidence suggests long non-coding RNA (lncRNA) H19 is associated with osteoarthritis (OA) pathology. However, how H19 contributes to OA has not been reported. This study aims to investigate the biological function of H19 in OA subchondral bone remodeling and OA progression. Clinical joint samples and OA animal models induced by medial meniscus destabilization (DMM) surgery were used to verify the causal relationship between osteocyte H19 and OA subchondral bone and cartilage changes. MLO-Y4 osteocyte cells subjected to fluid shear stress were used to verify the mechanism underlying H19-mediated mechano-response. Finally, the antisense oligonucleotide (ASO) against H19 was delivered to mice knee joints by magnetic metal-organic framework (MMOF) nanoparticles in order to develop a site-specific delivery method for targeting osteocyte H19 for OA treatment. Both clinical OA subchondral bone and wildtype mice with DMM-induced OA exhibit aberrant higher subchondral bone mass with more H19 expressing osteocytes. On the contrary, osteocyte-specific deletion of H19 mice is less vulnerable to DMM-induced OA phenotype. In MLO-Y4 cells, H19-mediated osteocyte mechano-response through PI3K/AKT/GSK3 signals activation by EZH2-induced H3K27me3 regulation on PP2A inhibition. Targeted inhibition of H19 (using ASO-loaded MMOF) substantially alleviates subchondral bone remodeling and OA phenotype. In summary, our results provide new evidence that the elevated H19 expression in osteocytes may contribute to aberrant subchondral bone remodeling and OA progression. H19 appears to be required for the osteocyte response to mechanical stimulation, and targeting H19 represents a new promising approach for OA treatment.

Arthroscopic meniscus transplant using autologous semitendinosus with bone marrow aspirate-derived fibrin clot along with anterior cruciate ligament reconstruction – A case report

Subtotal and total meniscectomy is known to advance osteoarthritis in patients. Meniscus transplant using semitendinosus autograft is a viable option in young patients. We have presented the early follow-up, along with technical video, for arthroscopic meniscus transplant with autologous semitendinosus graft with bone marrow aspirate-derived fibrin clot along with anterior cruciate ligament (ACL) reconstruction, in the primary surgery, in a patient of ACL tear along with near-complete loss of medial meniscus due to auto-meniscectomy. The patient showed good functional and radiological outcome at 9 months.

Ultrasound-guided injection using leucocyte-rich platelet-rich plasma for treatment of meniscal injuries in a duathlete: a case report.

There is a paucity of data regarding using platelet-rich plasma therapy for Baker's cyst-associated medial meniscal tear. To date, conservative treatments for this type of condition include aspiration of fluid effusion with steroid injection and physical therapy. When this treatment fails, arthroscopic debridement, meniscectomy, cyst decompression and open cystectomy are available surgical management options. Recurrence rates, however, are high such that even these procedures fail to provide long-term pain relief. This case study explores the benefits of leukocyte-rich platelet-rich plasma therapy in treating tears in the posterior horn of the medial meniscus with concomitant Baker's cyst. With limited studies available, this case hopes to encourage more studies to be done in the future to provide a conservative option for patients with similar cases.

Femoral cartilage defects initiate from medial meniscus extrusion or tibial cartilage lesions and expand in knee osteoarthritis as revealed by 3D MRI analysis

Knee osteoarthritis is characterized by articular cartilage wear, with its morphological progression not fully understood. This study aimed to elucidate factors contributing to femoral cartilage defects and their expansion in medial knee osteoarthritis, using a novel approach analyzing cross-sectional MRI data arranged by disease severity. From a cohort of 277 women in the Kanagawa Knee Study, we selected 17 knees that showed a cartilage area ratio < 0.99 in the posteromedial femoral cartilage region as the subjects for this study. The morphological relationships between femoral cartilage defects and menisci, as well as between femoral cartilage defects and tibial cartilage lesions, were investigated. Among subjects aged 30 to 79 years, the proportion was significantly higher in the 70–79 age group. In 11 cases, the outer edge of the cartilage defect was observed to coincide with the inner edge of the medial meniscus. Tibial cartilage lesions corresponded to femoral cartilage defects in 15 cases. Our 3D MRI analysis demonstrated that femoral cartilage defects were initially caused by either medial meniscus extrusion or kissing tibial cartilage lesions, with subsequent expansion of these defects resulting from the combined effects of ongoing medial meniscus extrusion and progressive tibial cartilage degeneration.Trial registration: UMIN, UMIN000032826; September 1, 2018.

Suture anchor and transtibial pullout refixation of the posterior medial meniscus root tears restore tibiofemoral contact pressure and area to intact meniscus levels.

To compare the load distributed to the medial tibial articular cartilage after refixation of posterior medial meniscus root tears between the suture anchor and transtibial pullout techniques in posterior medial meniscus root tears. Twelve Thiel's embalmed human cadaveric knees are used and divided into three groups (four knees in each group): (1) intact meniscus (IM), (2) fixation with suture anchor technique (SA) and (3) fixation with transtibial pullout technique (TP). Each group applies an axial compression load up to 1500 N by Instron E 10000 at two knee flexion angles (0° and 60°). A Tekscan 4000 pressure sensor is used to record the contact pressure and the contact area for each testing condition. The contact pressure and the contact area between the three conditions are not significantly different at 0° and 60° knee flexion angles. The peak contact pressure and contact area are 3734.8 ± 2642.2 kPa, 288.2 ± 115.0 mm2, 4510 ± 2930.5 kPa, 204.4 ± 36.8 mm2 and 5328.8 ± 2607.7 kPa, 219.2 ± 84.7 mm2 in IM, SA and TP, respectively. Both suture anchor and transtibial pullout refixation of PMMRT can restore contact pressure and contact area similar to the intact meniscus. This finding suggests that either technique can be reliably used in clinical practice to preserve joint function and potentially reduce the risk of osteoarthritis progression following posterior medial meniscus root tear repairs. Level III.

Survivorship and Outcomes of Meniscal Ramp Lesions Repaired Through a Posteromedial Portal During Anterior Cruciate Ligament Reconstruction: Outcome Study With a Minimum 10-Year Follow-up.

Several studies have demonstrated suture repair of ramp lesions of the medial meniscus via a posteromedial approach was associated with a significantly lower rate of secondary meniscectomy. However, these studies are not long-term and highlight the need for extended follow-up research to better understand the outcomes over a more extended period. To evaluate the long-term results and reoperation rate for the failure of arthroscopic all-inside suture repair of ramp lesions of the medial meniscus via a posteromedial approach during anterior cruciate ligament (ACL) reconstruction. Case series; Level of evidence, 4. All patients who underwent all-inside suture repair of the posterior segment of the medial meniscus (ramp lesion) via a posteromedial approach during ACL reconstruction at a minimum follow-up of 10 years were included in the study. Side-to-side anterior laxity was assessed preoperatively and postoperatively. Pre- and postoperative functional assessment was based on the subjective International Knee Documentation Committee score for activities of daily living and the Tegner activity scale for sporting ability. Reinterventions for meniscal repair failure and other complications were also recorded at the last follow-up. A total of 81 patients met the inclusion criteria for this study. Two patients had an ACL graft rupture with a new ramp lesion and were excluded from the analysis. Additionally, 15 patients were lost to follow-up, leaving a total of 64 patients in the final analysis. The mean follow-up was 124.8 months (range, 122.4-128.4 months). Mean side-to-side difference in anterior laxity significantly improved from 7.4 ± 1.5 mm (range, 5-12 mm) to 0.4 ± 1.3 mm (range, -3 to 4 mm) (P = .01). The mean subjective International Knee Documentation Committee score increased from 64.3 ± 13.4 (range, 34-92) before the operation to 91.1 ± 10.1 (range, 49-100) at the last follow-up (P = .001). The Tegner activity scale score at the last follow-up (6.3 ± 1.6) was lower than that before the trauma (7.1 ± 1.6) (P = .02). Fourteen patients (21.9%) had a failed meniscal repair and were reoperated. The mean time from initial repair to reoperation was 64.5 months (range, 13-126 months), and the median was 60.6 months. The multivariate analysis, including parameters such as lateral tenodesis (hazard ratio [HR], 1.62; P = .50), preoperative Tegner score (HR, 1.66; P = .41), preoperative laxity (HR, 1.75; P = .35), age at surgery (HR, 1.02; P = .97), and number of sutures (HR, 2.38; P = .19), did not reveal any factors associated with suture failure. The results show that arthroscopic repair of ramp lesions of the medial meniscus during ACL reconstruction using a posteromedial approach has a high failure rate at the 10-year follow-up, with half of these suture failures occurring within 5 years after the initial repair.

Differential effects of alendronate on chondrocytes, cartilage matrix and subchondral bone structure in surgically induced osteoarthritis in mice

Bisphosphonates (BP) are considered a treatment option for osteoarthritis (OA) due to reduction of OA-induced microtrauma in the bone marrow, stabilization of subchondral bone (SB) layer and pain reduction. The effects of high-dose alendronate (ALN) treatment on SB and articular cartilage after destabilization of the medial meniscus (DMM) or Sham surgery of male C57Bl/6J mice were analyzed. We performed serum analysis; histology and immunohistochemistry to assess the severity of OA and a possible pain symptomatology. Subsequently, the ratio of bone volume to total volume (BV/TV), epiphyseal trabecular morphology and the bone mineral density (BMD) was analyzed by nanoCT. Serum analysis revealed a reduction of ADAMTS5 level. The histological evaluation displayed no protective effect of ALN-treatment on cartilage erosion. NanoCT-analysis of the medial epiphysis revealed an increase of BV/TV in ALN-treated mice. Only the DMM group had significantly higher SB volume accompanied by decreased subchondral bone surface. Furthermore Nano-CT analysis revealed an increase in trabecular density and number, a decreased BMD and reduced osteophyte formation in the ALN mice. ALN treatment affected bone micro-architecture by reducing osteophytosis with simultaneous increasing subchondral bone plate thickness, trabecular thickness and BMD. Accordingly, ALN cannot be considered as a potential treatment strategy in general, however in a subgroup of patients with high bone turnover in an early-stage of OA, ALN might be an option when applied during a restricted time frame.

The Histopathological Examination of the Degeneration of Menisci in Osteoarthritic Knees Using an Adapted Bonar Score: Does Osteoarthritis Equally Influence the Lateral and Medial Menisci?

This study aimed to investigate the degeneration of the meniscal tissue in osteoarthritic knees and to adapt the Bonar score and its modifications to develop a microscopic examination. This study included consecutive patients who underwent total knee arthroplasty for symptomatic end-stage gonarthrosis. During the surgery, the menisci were completely dissected to preserve their original shapes. The samples were prepared using the hematoxylin and eosin (H&amp;E) staining method and the Alcian blue protocol and were examined under light microscopy. The extent of histopathological changes was assessed based on the classical Bonar score assumptions. Additionally, in the second step of the examination, menisci remnants were evaluated using the modified Bonar score developed by Zabrzyński et al. The study involved 44 patients, from whom 83 samples of knee menisci were obtained. Histological examination of the meniscal specimens under a light microscope revealed tissue degeneration in all cases, in both the medial and lateral menisci. The mean classical Bonar score was 8.3571 and the mean modified Bonar score was 6.9398. There were no statistically significant differences in classical Bonar score assessment between medial and lateral menisci (p = 0.3014). There were no statistically significant differences in the modified-Bonar score assessment between medial and lateral menisci (p = 0.3620). We show that both menisci are implicated in the degenerative process, with high scores in the Bonar system, regardless of knee axial deformity. The Bonar score, along with its modifications, can be readily employed in the microscopic assessment of meniscus pathology.

A Case Report of a Rare Presentation of Semimembranosus Tibial Plateau Avulsion: The Bony Ramp Lesion

Background: Tibial plateau posteromedial rim avulsions by semimembranosus tendon are a rare entity that have been reported in a few studies so far with controversial mechanisms. They are reported to accompany anterior cruciate ligament (ACL) or meniscal injuries. Their main fracture planes are usually placed in the coronal plane. Case Report: The patient was a 52-year-old man with a hyperextension-valgus tibial plateau fracture. The imaging studies revealed a compression fracture of the lateral and an avulsion fracture of the posteromedial plateau. However, no soft-tissue injuries were detected. The fragment was avulsed in the axial plane and covered by the medial meniscal posterior horn, creating the pattern of a longitudinal tear in the meniscal ramp lesion, but actually without any soft-tissue injuries. It was fixated using the tension band wiring technique with two Kirschner wires (K-wires) and one cancellous screw. Radiological and functional outcomes were excellent at 12-month follow-up. Conclusion: This fracture pattern merits special attention due to its unusual presentation, causing the meniscal posterior horn to separate from the articular surface. “Bony ramp lesion” best describes the simultaneous separation of the posterior horn of the medial meniscus (PHMM) and its underlying bony fragment without the meniscal tear that takes place in an actual medial meniscal ramp lesion.

Resatovir Combined with Glycyrrhizic Acid Ameliorates Osteoarthritis and Enhances Autophagy in Chondrocytes

Background Osteoarthritis (OA) is a chronic disease worldwide. With resatovir usually used as an inhibitor, resatovir and glycyrrhizic acid have several pharmacological activities. Purpose We intend to explore the mechanism underlying resatovir combined with glycyrrhizic acid in OA. Methods After the establishment of an animal model of OA through anterior cruciate ligament transection and destabilization of the medial meniscus, the rats were subjected to intramuscular injection of resatovir combined with glycyrrhizic acid (60 mg/kg) or 5% glucose (60 mg/kg) every day for 4 weeks. During the progress, the rat movement and the bend score of knees were observed through behavioral studies. Additionally, the SKP2 gene expression and toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB)-related signaling pathways were examined, as apoptosis and autophagy were evaluated by flow cytometry. Results With increased inflammatory cells in the model group, treatment with resatovir combined with glycyrrhizic acid significantly decreased the number of inflammatory cells. Meanwhile, the treatment resulted in decreased SKP2 expression in OA cells when hindering the migration of preosteoclast cells. Interestingly, it was observed that the bend score increased over the treatment with resatovir plus glycyrrhizic acid and TIPPI% declined dramatically. Resatovir treatment enhanced autophagy and apoptosis in OA cells and decreased pP65, P65, and LC3 expression. Conclusion Resatovir combined with glycyrrhizic acid can inhibit the inflammatory response through decreasing SKP2 expression and induce autophagy activation in OA cells through TLR4/NF-κB signaling, thereby attenuating OA progression.

Using an aqueous solution of hydrolyzed collagen in phosphate buffer (drug Compositron) and vitamin D in patients with osteoarthritis of the knee joint complicated by medial meniscus injury

Using an aqueous solution of hydrolyzed collagen in phosphate buffer (drug Compositron) and vitamin D in patients with osteoarthritis of the knee joint complicated by medial meniscus injury

Assessment of validity, reliability, and feasibility of OMERACT ultrasound knee osteoarthritis scores in Egyptian patients with primary knee osteoarthritis.

Ultrasound (US) can evaluate all joint components affected by knee osteoarthritis (KOA); however, standardized scoring of US-detected pathology is needed to improve its diagnostic and monitoring capabilities. To examine the validity, reliability, and feasibility of the Outcome Measures in Rheumatology (OMERACT) ultrasound scoring for KOA, comparing with clinical and radiography measures, using predefined cutoff values. This cross-sectional study included 75 Egyptian patients with primary KOA. All patients had Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, bilateral knee radiography, and ultrasonography. Inter-observer reliability of ultrasound was evaluated in 30 knees by another newly trained operator. Most of the OMERACT-US KOA scores showed significant associations with WOMAC clinical scores, except for femoral cartilage damage and effusion. The synovitis score was significantly associated with WOMAC-pain score (p-value 0.046), while medial meniscus extrusion (MME) and medial osteophytes were significantly associated with WOMAC-stiffness score (p-value 0.009 and 0.023, respectively). MME and synovitis were significantly associated with WOMAC-physical score (p-value 0.035 and 0.020, respectively). The ultrasound scores also showed a strong correlation with radiographic scoring. Inter-observer reliability ranged from moderate to excellent agreement (k = 0.58 to k = 0.83); it was highest for lateral osteophytes (k = 0.83), good agreement for synovitis (k = 0.72), any osteophytes (k = 0.71), damage of femoral cartilage (k = 0.70), and moderate agreement for medial osteophytes (k = 0.58) and MME (k = 0.59). OMERACT-US scoring system for KOA demonstrated validity, reliability, and feasibility for evaluating both structural and inflammatory components. Using cutoff values improved the scoring reliability for osteophytes and MME. Key Points • OMERACT-US scores provide a valid assessment of inflammatory and structural components of knee osteoarthritis. • The following changes may improve the performance of the OMERACT-US scores. a. The binary score for effusion and synovial hypertrophy can be omitted, as they have no added value. b. A semi-quantitative grading for effusion may capture the impact of effusion on clinical outcomes. c. Added cutoff values to score medial meniscal extrusion, osteophytes, and pathological effusion improved the respective scores' reliability. d. Applying the updated OMERACT definition of synovitis. • OMERACT-US scores are reliable to be used with a newly trained operator, particularly when cutoff values are included, and proper training time is provided. • The OMERACT-US score is feasible to be used in clinical practice, as the time taken to perform was short, even for a newly trained operator.

The Utility of a Community-Based Knee Ultrasound in Detecting Meniscal Tears: A Retrospective Analysis in Comparison with MRI.

MRI is the gold standard for detecting meniscal tears; however, ultrasound may readily detect meniscal changes, obviating the need for MRI. We aim to (1) determine ultrasound sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy in detecting meniscal changes, and (2) describe characteristic meniscal changes in US and their prevalence. A retrospective analysis of knee ultrasound scans for the presence of medial and lateral meniscal tears was conducted. Meniscal changes were characterized into five US appearances (cleft, diminutive, cyst, displaced fragment, and extrusion) by the consensus of two musculoskeletal radiologists. Ultrasound findings were then compared to MRI results. In total, 249 patients were included. Ultrasound sensitivity, specificity, PPV, NPV, and accuracy for medial meniscal tears were 79%, 97.3%, 95.3%, 86.6%, and 90%, respectively, and for lateral meniscal tears the ultrasound sensitivity, specificity, PPV, NPV, and accuracy were 63%, 99.5%, 96%, 93%, and 93.6%, respectively. The false negative and false positive rates for medial meniscal tears were 13.4% and 4.7%, respectively, and for the lateral meniscus, the false negative and false positive rates were 6.7% and 3.8%, respectively. Meniscal clefts were the most prevalent appearance in the medial meniscus followed by extrusions. Meniscal extrusions were the most prevalent appearance in the lateral meniscus followed by clefts. Community-based US is highly accurate in the detection of meniscal tears when compared with MRI, making it a valuable diagnostic imaging tool for detecting meniscal tears in a community setting where accessibility to MRI is limited or if there are MRI contraindications.

Preservation of the MMPH and Status of the Notch Configurations Are Important Factors for Successful Revision ACL Reconstruction.

The aim of this study was to identify the differences in anatomical factors between the patients who underwent revision and primary anterior cruciate ligament reconstructions (ACLR) and compare the outcomes between the 2 surgeries. Retrospective cohort study. Single institution tertiary academic center between 2014 and 2020. A total of 84 matched patients who underwent revision (group I) or primary ACLR (group II). Radiological evaluations were performed using side-to-side differences (SS-D), femorotibial angle, and posterior tibial slope. The medial meniscus posterior horn status as width (MMPHW), medial tibial plateau width (MTPW), notch configurations, tunnel positions, and sagittal graft angle were measured using 3D-CT and magnetic resonance imaging (MRI). Graft signals were assessed using MRI. The clinical outcomes were assessed. Group I showed larger SS-D and higher mean Howell grade of anterior cruciate ligament (ACL) graft than group II (P = 0.002 and P = 0.004, respectively). Multivariate regression analyses showed that the decreased MMPHW/MTPW ratio (P = 0.010) and notch width index (P < 0.007) were significantly independent factors associated with the higher Howell grade of ACL grafts. The decreased MMPHW/MTPW ratio (P < 0.001) was a significantly independent factor associated with larger SS-D. In the subgroup analysis, all patients in the notchplasty group showed wider notches postoperatively (P < 0.001). Revision ACLRs resulted in worse ACL signal intensity and stability outcome. The results of this study suggest that it may be important to preserve the MMPHW as much as possible and check notch configurations, especially during a revision ACLR.

Amentoflavone maintaining extracellular matrix homeostasis and inhibiting subchondral bone loss in osteoarthritis by inhibiting ERK, JNK and NF-κB signaling pathways

Amentoflavone (AF), a plant biflavone isolated from Selaginella sinensis ethanol extract, is characterized by anti-inflammatory and anti-oxidant properties. According to previous studies, inflammation and oxidative stress are closely related to the pathophysiology of osteoarthritis (OA). However, the effects and mechanisms of AF on OA have not been elucidated.To investigate the inhibitory effects and its molecular mechanism of AF on extracellular matrix (ECM) degradation stimulated by IL-1β as well as subchondral bone loss induced by RANKL in mice chondrocytes. Quantitative PCR was used to detect the mRNA expression of genes related to inflammation, ECM, and osteoclast differentiation. Protein expression level of iNOS, COX-2, MMP13, ADAMTS5, COL2A1, SOX9, NFATc1, c-fos, JNK, ERK, P65, IκBα was measured by western blotting. The levels of TNF-α and IL-6 in the supernatants were measured by ELISA. The amount of ECM in chondrocytes was measured using toluidine blue staining. The levels of Aggrecan and Col2a1 in chondrocytes were measured using immunofluorescence. Tartrate-resistant acid phosphatase (TRAP) staining, F-actin staining and immunofluorescence were used to detect the effect of AF on osteoclast differentiation and bone resorption. The effect of AF on destabilization of the medial meniscus (DMM)-induced OA mice can be detected in hematoxylin–eosin (H&E) staining, Safranin O green staining and immunohistochemistry.AF might drastically attenuated IL-1β-stimulated inflammation and reduction of ECM formation by blocking ERK and NF-κB signaling pathways in chondrocytes. Meanwhile, AF suppressed the formation of osteoclasts and the resorption of bone function induced by RANKL. In vivo, AF played a protective role by stabilizing cartilage ECM and inhibiting subchondral bone loss in destabilization of the medial meniscus (DMM)-induced OA mice, further proving its protective effect in the development of OA. Our study show that AF alleviated OA by suppressing ERK, JNK and NF-κB signaling pathways in OA models in vitro and DMM-induced OA mice, suggesting that AF might be a potential therapeutic agent in the treatment of OA.

Evaluation of the reliability and accuracy of MRI for the diagnosis of meniscal ramp lesions.

Meniscal ramp lesions are a special type of meniscal injury that affects the periphery of the posterior horn of the medial meniscus and/or its meniscocapsular attachments, strongly associated with anterior cruciate ligament (ACL) tears. Due to their location, these lesions can be missed arthroscopically so it is essential to diagnose them on preoperative magnetic resonance imaging (MRI). To evaluate the accuracy of MRI in detecting meniscal ramp lesions in patients with ACL tears using arthroscopy as the reference standard. Two musculoskeletal radiologists, blinded to the surgical findings, retrospectively and independently evaluated 106 knee MRI scans for the presence of meniscal ramp lesions in non-consecutive patients who underwent arthroscopic ACL reconstruction between January 2019 and July 2022 by a single surgeon at one institution. Having arthroscopy as reference, the diagnostic sensitivity and specificity as well as the positive and negative predictive values (PPV/NPV) of the MRI scans were calculated. Cohen's kappa coefficient was used to test inter-observer reliability. A P value <0.05 was considered statistically significant. In the study group of 106 patients (72 men, 34 women; mean age = 33.84 ±13.12 years), 76 had an arthroscopy-confirmed meniscal ramp lesion, while 30 did not. The sensitivity and specificity of MRI for the detection of meniscal ramp lesion were 88% and 87%, respectively. The PPV and NPV were 94% and 74%, respectively. Inter-rater reliability was excellent (k = 0915). This study demonstrates that MRI can accurately detect meniscal ramp lesions.

Gene therapy for fat-1 prevents obesity-induced metabolic dysfunction, cellular senescence, and osteoarthritis

Obesity is one of the primary risk factors for osteoarthritis (OA), acting through cross talk among altered biomechanics, metabolism, adipokines, and dietary free fatty acid (FA) composition. Obesity and aging have been linked to cellular senescence in various tissues, resulting in increased local and systemic inflammation and immune dysfunction. We hypothesized that obesity and joint injury lead to cellular senescence that is typically associated with increased OA severity or with aging and that the ratio of omega-6 (ω-6) to omega-3 (ω-3) FAs regulates these pathologic effects. Mice were placed on an ω-6-rich high-fat diet or a lean control diet and underwent destabilization of the medial meniscus to induce OA. Obesity and joint injury significantly increased cellular senescence in subcutaneous and visceral fat as well as joint tissues such as synovium and cartilage. Using adeno-associated virus (AAV) gene therapy for fat-1, a fatty acid desaturase that converts ω-6 to ω-3 FAs, decreasing the serum ω-6:ω-3 FA ratio had a strong senomorphic and therapeutic effect, mitigating metabolic dysfunction, cellular senescence, and joint degeneration. In vitro coculture of bone marrow-derived macrophages and chondrocytes from control and AAV8-fat1-treated mice were used to examine the roles of various FA mediators in regulating chondrocyte senescence. Our results suggest that obesity and joint injury result in a premature "aging" of the joint as measured by senescence markers, and these changes can be ameliorated by altering FA composition using fat-1 gene therapy. These findings support the potential for fat-1 gene therapy to treat obesity- and/or injury-induced OA clinically.

Arthroscopic Repair of Medial Meniscus Posterior Root Tear with Adjustable Titanium Plate Fixation.

Medial meniscus injury is one of the most prevalent knee disorders, with posterior root tears occurring in approximately 10% to 21% of affected individuals. A posterior root tear disrupts the meniscus's continuous annular structure, compromising its ability to absorb pressure and protect the knee's articular cartilage. If left untreated, this can result in increased stress on the cartilage, leading to conditions such as varus deformity and accelerated joint degeneration. Partial removal (resection) of the medial meniscus further exacerbates these issues, often leading to quicker joint deterioration. Repairing medial meniscus posterior root tears (MMPRTs) plays a crucial role in restoring the meniscus's structural integrity and improving knee biomechanics. Studies have shown that compared to partial medial meniscectomy or conservative treatments, repairing MMPRTs enhances clinical outcomes and significantly delays the onset of arthritis. This article details a surgical procedure that uses a single-suture, double-loop, adjustable titanium plate fixation technique under arthroscopy for effective MMPRT repair.

Beyond the Surface: Investigating Clinical and Magnetic Resonance Imaging Dynamics in Knee Injuries: A Cross-sectional Study

Abstract Context: Orthopedic surgeons frequently encounter knee soft tissue injuries such as meniscal and ligament injuries. This study seeks to explore the diagnostic efficacy of clinical examination, magnetic resonance imaging (MRI), and arthroscopy in identifying knee injuries. Subjects and Methods: This prospective observational study enrolled 120 patients with knee injuries slated for arthroscopic surgery based on clinical and MRI assessments. The study assessed and compared the diagnostic accuracy of clinical and MRI findings. Statistical Analysis Used: Statistical analysis was performed using SPSS software (SPSS Inc., Chicago, IL, USA) for the Windows program (21.0 version). The Spearman correlation analysis was done to assess the relationship between the various parameters. The level of agreement was assessed using Cohen’s kappa statistics. Interpretation of kappa statistics is as follows: 0 to 0.20-Slight agreement; 0.1 to 0.39-Fair; 0.40 to 0.59-Moderate; 0.60 to 0.79- Substantial and 0.80 to 0.90-Almost perfect agreement. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated and observed by using 2 × 2 contingency table. P &lt; 0.05 was considered statistically significant. Results: When comparing MRI and arthroscopy findings, the anterior cruciate ligament (ACL) tear exhibited the highest sensitivity and specificity at 100.00% and 91.84%, respectively, while the medial meniscus tear had the lowest sensitivity and specificity at 80.23% and 61.76%. Regarding the comparison between clinical examination and arthroscopy, the Lachman test displayed the highest sensitivity at 95.92%, whereas McMurray’s test (Lateral Meniscus) had the lowest sensitivity at 54.55%, and the posterior Drawer’s test showed the lowest specificity at 60.00%. Lachman also demonstrated the highest diagnostic accuracy at 98.33%, while the posterior Drawer’s test had the lowest diagnostic accuracy at 70.00%. Conclusions: Despite a few limitations, clinical examination and MRI currently stand out as the most precise non-invasive methods for detecting abnormalities in the menisci and the ACL. These diagnostic approaches provide valuable insights into the structural integrity of these knee components, allowing for a comprehensive assessment without the need for invasive procedures.

Osteoarthritis early-, mid- and late-stage progression in the rat medial meniscus transection model.

Osteoarthritis is a degenerative disease of synovial joints affecting all tissues, including articular cartilage and subchondral bone. Osteoarthritis animal models can recapitulate aspects of human disease progression and are used to test efficacy of drugs, biomaterials, and cell therapies. The rat medial meniscus transection (MMT) model is a surgically induced posttraumatic osteoarthritis model commonly used for preclinical therapeutic screening. We describe herein, the qualitative and quantitative changes to articular cartilage, subchondral bone, and formation of osteophytes at early-, mid-, and late-stages of osteoarthritis progression. Tibia of MMT-operated animals showed proteoglycan loss and fibrillation along articular cartilage surfaces as early as 3-weeks post-surgery. With contrast-enhanced micro-CT technique, quantitative, 3-dimensional analysis of the tibia showed that the articular cartilage thickened at 3- and 6-weeks post-surgery and decreased at 12-weeks post-surgery. This decreased cartilage thickness corresponded with increased lesions in the articular cartilage that led to its full degradation and exposing the subchondral bone layer. Further, subchondral bone thickening was significant at 6-weeks post-surgery and followed cartilage damage. Osteophytes were found as early as 3-weeks post-surgery and coincided with articular cartilage degradation. Cartilaginous osteophytes preceded mineralization, suggesting endochondral ossification. The rat MMT model has predominantly been used out to 3-weeks, and most studies determined the effect of therapies to delay or prevent the onset of osteoarthritis. We provide evidence that an extension of the rat MMT model out to 6- and 12-weeks more resembled severe phenotypes of human osteoarthritis. Thus, evaluating novel therapeutics at late-stage will be important for eventual clinical translation.