Achieving high accuracy in meniscus tear detection using advanced deep learning models with a relatively small data set.

PURPOSE: This study aims to evaluate the effectiveness of advanced deep learning models, specifically YOLOv8 and EfficientNetV2, in detecting meniscal tears on magnetic resonance imaging (MRI) using a relatively small data set. METHOD: Our data set consisted of MRI studies from 642 knees-two orthopaedic surgeons labelled and annotated the MR images. The training pipeline included MRI scans of these knees. It was divided into two stages: initially, a deep learning algorithm called YOLO was employed to identify the meniscus location, and subsequently, the EfficientNetV2 deep learning architecture was utilized to detect meniscal tears. A concise report indicating the location and detection of a torn meniscus is provided at the end. RESULT: The YOLOv8 model achieved mean average precision at 50% threshold (mAP@50) scores of 0.98 in the sagittal view and 0.985 in the coronal view. Similarly, the EfficientNetV2 model obtained area under the curve scores of 0.97 and 0.98 in the sagittal and coronal views, respectively. These outstanding results demonstrate exceptional performance in meniscus localization and tear detection. CONCLUSION: Despite a relatively small data set, state-of-the-art models like YOLOv8 and EfficientNetV2 yielded promising results. This artificial intelligence system enhances meniscal injury diagnosis by generating instant structured reports, facilitating faster image interpretation and reducing physician workload. LEVEL OF EVIDENCE: Level III.

Management of Meniscus Pathology with Concomitant Anterior Cruciate Ligament Injury.

PURPOSE OF REVIEW: The purpose of this review is to summarize current clinical knowledge on the prevalence and types of meniscus pathology seen with concomitant anterior cruciate ligament (ACL) injury, as well as surgical techniques, clinical outcomes, and rehabilitation following operative management of these pathologies. RECENT FINDINGS: Meniscus pathology with concomitant ACL injury is relatively common, with reports of meniscus pathology identified in 21-64% of operative ACL injuries. These concomitant injuries have been associated with increased age and body mass index. Lateral meniscus pathology is more common in acute ACL injury, while medial meniscus pathology is more typical in chronic ACL deficiency. Meniscus tear patterns associated with concomitant ACL injury include meniscus root tears, lateral meniscus oblique radial tears of the posterior horn (14%), and ramp lesions of the medial meniscus (8-24%). These meniscal pathologies with concomitant ACL injury are associated with increased rotational laxity and meniscal extrusion. There is a paucity of comparative studies to determine the optimal meniscus repair technique, as well as rehabilitation protocol, depending on specific tear pattern, location, and ACL reconstruction technique. There has been a substantial increase in recent publications demonstrating the importance of meniscus repair at the time of ACL repair or reconstruction to restore knee biomechanics and reduce the risk of progressive osteoarthritic degeneration. Through these studies, there has been a growing understanding of the meniscus tear patterns commonly identified or nearly missed during ACL reconstruction. Surgical management of meniscal pathology with concomitant ACL injury implements the same principles as utilized in the setting of isolated meniscus repair alone: anatomic reduction, biologic preparation and augmentation, and circumferential compression. Advances in repair techniques have demonstrated promising clinical outcomes, and the ability to restore and preserve the meniscus in pathologies previously deemed irreparable. Further research to determine the optimal surgical technique for specific tear patterns, as well as rehabilitation protocols for meniscus pathology with concomitant ACL injury, is warranted.

The Usefulness of Posterior Shiny Corner Lesions in the Early Diagnosis of Medial Meniscus Posterior Root Tears.

INTRODUCTION:  Posterior shiny corner lesions (PSCLs) have been reported to be useful for the early diagnosis of medial meniscus posterior root tears (MMPRTs) in surgical patients. However, the usefulness of PSCLs in outpatients, particularly regarding the optimal timing of magnetic resonance imaging (MRI) examinations after injury, remains unknown. We hypothesized that PSCLs would normally be observed in patients with MMPRTs within one month of injury. MATERIALS AND METHODS:  This study included 144 patients with knee pain who visited our hospital between January 2021 and May 2023. MRI findings within and after one month were examined. Fisher's exact test was performed for PSCLs, cleft signs, ghost signs, radial tear signs, bone cysts, and medial meniscus extrusion (MME), which are findings used for the diagnosis of MMPRTs. Time-dependent receiver operating characteristic (ROC) curve analysis was performed for each MRI finding. A binomial logistic regression analysis was performed for age, sex, PSCL, ghost sign, and MME. RESULTS: PSCLs were observed on 82.6% of the MRI scans within one month, but the positivity rate decreased after one month. After one month, a high percentage of patients had cleft signs and ghost signs. The results of a time-dependent ROC curve analysis showed that the PSCL had better diagnostic ability than the cleft sign, ghost sign, radial tear sign, and MME at a relatively early stage. Additionally, the area under the curve (AUC) of PSCL peaks around 35 days and then declines, reaching 0.8 or less around 40 days. On the other hand, the AUC of the cleft sign and ghost sign began to increase around 30 days after injury, and it exceeded 0.8 after approximately 100 days. The results of the binomial logistic regression analysis revealed significant PSCLs and ghost signs. Independent associations between the PSCL, or ghost sign, and the MMPRT were demonstrated. CONCLUSION:  This study suggests that PSCLs have a superior diagnostic capability for MMPRT during the early stages of injury compared with other MRI findings in outpatients. In particular, PSCLs have a high positivity rate within one month after injury and a high diagnostic capacity up to 40 days after injury.

Excellent accuracy of magnetic resonance imaging for diagnosis of discoid meniscus tears: A systematic review and meta-analysis.

Purpose: The discoid meniscus (DM) is distinguished by its thickened, disc-shaped formation, which extends over the tibial plateau. The likelihood of developing osteoarthritis escalates if a DM tear remains undiagnosed and untreated. While DM tears can be diagnosed through arthroscopy, the high cost, invasive nature and limited availability of this procedure highlight the need for a better diagnostic modality. This study aims to determine the accuracy of magnetic resonance imaging (MRI) in diagnosing DM tears. Methods: A systematic review was conducted to gather articles with at least 10 cases on the comparison of MRI and arthroscopy as the gold standard for DM tear diagnosis. Stata and MetaDisc were used to conduct the statistical analysis. The quality of the included studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Results: Five diagnostic performance studies, derived from four original research papers involving 305 patients, were evaluated. Based on the pooled data, the sensitivity, specificity, diagnostic odds ratio, positive limit of detection and negative limit of detection were found to be 0.87 (95% confidence interval [CI], 0.82-0.91) and 0.84 (95% CI, 0.75-0.90), 32.88 (95% CI, 5.81-186.02), 5.22 (95% CI, 1.71-15.92) and 0.18 (95% CI, 0.09-0.38), respectively. A hierarchical summary receiver operating characteristic curve with an area under the curve of 0.92 was generated. Conclusion: This meta-analysis demonstrates that MRI has excellent sensitivity and specificity for diagnosing DM tears. Despite its lower accuracy compared to arthroscopy, MRI can be used in symptomatic patients as a viable alternative to arthroscopy due to its inherent advantages. Level of Evidence: Level IV.

A Comprehensive Evaluation of Deep Learning Models on Knee MRIs for the Diagnosis and Classification of Meniscal Tears: A Systematic Review and Meta-Analysis.

OBJECTIVES: This study delves into the cutting-edge field of deep learning techniques, particularly deep convolutional neural networks (DCNNs), which have demonstrated unprecedented potential in assisting radiologists and orthopedic surgeons in precisely identifying meniscal tears. This research aims to evaluate the effectiveness of deep learning models in recognizing, localizing, describing, and categorizing meniscal tears in magnetic resonance images (MRIs). MATERIALS AND METHODS: This systematic review was rigorously conducted, strictly following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Extensive searches were conducted on MEDLINE (PubMed), Web of Science, Cochrane Library, and Google Scholar. All identified articles underwent a comprehensive risk of bias analysis. Predictive performance values were either extracted or calculated for quantitative analysis, including sensitivity and specificity. The meta-analysis was performed for all prediction models that identified the presence and location of meniscus tears. RESULTS: This study's findings underscore that a range of deep learning models exhibit robust performance in detecting and classifying meniscal tears, in one case surpassing the expertise of musculoskeletal radiologists. Most studies in this review concentrated on identifying tears in the medial or lateral meniscus and even precisely locating tears-whether in the anterior or posterior horn-with exceptional accuracy, as demonstrated by AUC values ranging from 0.83 to 0.94. CONCLUSIONS: Based on these findings, deep learning models have showcased significant potential in analyzing knee MR images by learning intricate details within images. They offer precise outcomes across diverse tasks, including segmenting specific anatomical structures and identifying pathological regions. Contributions: This study focused exclusively on DL models for identifying and localizing meniscus tears. It presents a meta-analysis that includes eight studies for detecting the presence of a torn meniscus and a meta-analysis of three studies with low heterogeneity that localize and classify the menisci. Another novelty is the analysis of arthroscopic surgery as ground truth. The quality of the studies was assessed against the CLAIM checklist, and the risk of bias was determined using the QUADAS-2 tool.

Secondary restraints in ACL reconstruction: State-of-the-art.

At-risk patients continue to experience a high likelihood of graft rupture after anterior cruciate ligament (ACL) reconstruction (ACLR). This narrative review seeks to provide the reader with an evidence-based synopsis of state-of-the-art concepts related to secondary restraint lesions, and how addressing them surgically might result in improved outcomes of ACLR.

A Rare Case of Arthroscopic Lateral Segmental Meniscal Allograft Transplantation (SMALT) and Osteochondral Allograft Transplantation (OCA) of the Lateral Femoral Condyle Augmented With Bone Marrow Aspirate Concentrate (BMAC).

The meniscus of the knee serves as a crucial load-bearing structure, and its damage can significantly impact weight distribution. In addressing focal meniscal defects, segmental meniscal allograft transplantation (SMALT) emerges as an innovative solution. Here, we detail a case involving a young, active female who underwent SMALT augmented with osteochondral allograft transplantation (OCA) and bone marrow aspirate concentration (BMAC). The patient, a 40-year-old former Division I volleyball player, previously underwent arthroscopic procedures and presented with knee pain alongside complex lateral meniscus tear evident in magnetic resonance imaging (MRI) findings. Initial arthroscopy revealed multiple tears, including segmental deficiency at the posterior horn-body junction and a horizontal cleavage tear. Despite failed attempts at repair due to the meniscal gap, a second-stage lateral SMALT was performed, with the allograft soaked in the patient's BMAC, supplemented with OCA to the lateral femoral condyle. Rehabilitation protocols tailored to both SMALT and OCA were implemented. This represents the first documented instance of lateral SMALT, extending the scope of viable solutions for segmental meniscal deficiencies, and marking a significant milestone in orthopedic practice.

Decay-Accelerating Factor Differentially Associates With Complement-Mediated Damage in Synovium After Meniscus Tear as Compared to Anterior Cruciate Ligament Injury.

We have reported that anterior cruciate ligament (ACL) injury leads to the differential dysregulation of the complement system in the synovium as compared to meniscus tear (MT) and proposed this as a mechanism for a greater post-injury prevalence of post traumatic osteoarthritis (PTOA). To explore additional roles of complement proteins and regulators, we determined the presence of decay-accelerating factor (DAF), C5b, and membrane attack complexes (MACs, C5b-9) in discarded surgical synovial tissue (DSST) collected during arthroscopic ACL reconstructive surgery, MT-related meniscectomy, osteoarthritis (OA)-related knee replacement surgery and normal controls. Multiplexed immunohistochemistry was used to detect and quantify complement proteins. To explore the involvement of body mass index (BMI), after these 2 injuries, we examined correlations among DAF, C5b, MAC and BMI. Using these approaches, we found that synovial cells after ACL injury expressed a significantly lower level of DAF as compared to MT (p<0.049). In contrast, C5b staining synovial cells were significantly higher after ACL injury (p<0.0009) and in OA DSST (p<0.039) compared to MT. Interestingly, there were significantly positive correlations between DAF & C5b (r=0.75, p<0.018) and DAF & C5b (r=0.64 p<0.022) after ACL injury and MT, respectively. The data support that DAF, which should normally dampen C5b deposition due to its regulatory activities on C3/C5 convertases, does not appear to exhibit that function in inflamed synovia following either ACL injury or MT. Ineffective DAF regulation may be an additional mechanism by which relatively uncontrolled complement activation damages tissue in these injury states.

Examining the Evidence Regarding Smoking and Patient Outcomes for Isolated Meniscus Pathology: A Comprehensive Systematic Review and Meta-Analysis.

Smoking is a well-known cause of impairment in wound healing and postoperative outcomes; however, its effects on treating meniscus issues remain unclear. This study assesses the relationship between smoking and meniscus treatment outcomes. PubMed, Scopus, Cochrane, and CINAHL were searched from inception to 24 December 2023. Inclusion criteria encompassed studies examining smoking's impact on patient outcomes regarding meniscus pathology. A secondary PubMed search targeted randomized controlled trials (RCTs) in the top ten orthopedic journals focusing on meniscus pathology and smoking as a demographic variable. Meta-analysis of six studies (n = 528) assessed meniscus failure rate based on smoking status. Eighteen observational studies (n = 8353 patients; 53.25% male; mean age: 51.35 ± 11.53 years; follow-up: 184.11 ± 117.34 months) were analyzed, covering meniscus repair, meniscectomy, allograft transplant, conservative care, and arthroscopy. Results showed four studies (36.36%) linked smoking with worse meniscus repair outcomes, while seven studies (63.64%) did not find significant associations. Meta-analysis from six studies showed no significant impact of smoking on repair failure (p = 0.118). Regarding meniscectomy, one study (33.33%) identified a significant association with smoking, but two did not. Only one (3.8%) of the RCTs in leading orthopedic journals included smoking as a factor. The evidence on smoking's effect on meniscus treatment is mixed, necessitating further investigation.

The Impact of Bone Marrow Venting Augmentation on Knee Functions in the Repair of Vertical/Longitudinal Meniscus Tears: A Triple Comparison.

Objective: Preserving and restoring meniscus function is crucial for maintaining knee biomechanics and overall functionality. To enhance the healing process after meniscus repair, various biological techniques have been introduced. In this study, three treatment approaches examined were bone marrow venting with stem cells (BMVP), anterior cruciate ligament reconstruction (ACLR) with meniscus repair, and isolated meniscus repair. Materials and Methods: From 2015 to 2019, we retrospectively analyzed data from 83 patients who presented with complaints of knee pain or pain in addition to instability, were diagnosed with vertical/longitudinal meniscus tears, and underwent arthroscopic repair (30 with isolated repair, 28 with ACLR repair, and 25 with BMVP) at our University Hospital. Among the 28 patients with anterior cruciate ligament rupture, pain and instability were the predominant complaints, whereas 55 patients with meniscus tear primarily complained pain. Clinical and functional conditions were assessed using Lysholm, WOMAC, IKDC, and VAS scores before and 18 months after surgery. Surgical success was evaluated based on Barrett's criteria. Causes of failure were analyzed considering demographic data, smoking status, injury time, tear location, shape, zone, and suture type and number. Results: Of the participants, 58 were male, 25 were female, 61 had medial meniscus lesions, and 22 had lateral meniscus lesions. The tear types included 51 simple longitudinal tears, 18 bucket handle tears, and 14 complex tears. A significant improvement was observed in the postoperative 18 month Lysholm, WOMAC, and IKDC values in all three groups (p: 0.001). At the 18 month mark, clinical and functional outcomes were comparable between BMVP and ACLR repair groups (Lysholm p: 0.951, WOMAC p: 0.241, IKDC p: 0.984). Both of these procedures yielded better results compared to isolated meniscus repair (Lysholm p: 0.001, WOMAC p: 0.027, IKDC p: 0.001). Conclusion: The superior clinical and functional outcomes observed after meniscus repair with BMVP and ACLR, compared to isolated meniscus repair, indicate positive effects of bone marrow stem cells, blood components, and tissue healing factors on meniscus repair and knee function.

The mediating role of synovitis in meniscus pathology and knee osteoarthritis radiographic progression.

Meniscus pathologies (damage, extrusion) and synovitis are associated with knee osteoarthritis (KOA); however, whether synovitis mediates the relationship between meniscus pathologies and KOA radiographic progression remains unclear. We conducted an observational study in the Osteoarthritis Initiative (OAI) cohort, with a 48-month follow-up. Meniscus pathology and synovitis were measured by MRI osteoarthritis knee score (MOAKS) at baseline and 24 months, and a comprehensive synovitis score was calculated using effusion and Hoffa synovitis scores. The knee osteoarthritis radiographic progression was considered that Kellgren-Lawrence (KL) grade and joint space narrowing (JSN) grade at 48 months were increased compared to those at baseline. This study included a total of 589 participants, with KL grades mainly being KL1 (26.5%), KL2 (34.1%), and KL3 (30.2%) at baseline, while JSN grades were mostly 0 at baseline. A logistic regression model was used to analyze the relationship between meniscus pathology, synovitis, and KOA progression. Mediation analysis was used to evaluate the mediation effect of synovitis. The average age of the participants was 61 years old, 62% of which were female. The medial meniscus extrusion was longitudinally correlated with the progression of KL (odds ratio [OR]: 2.271, 95% confidence interval [CI]: 1.412-3.694) and medial JSN (OR: 3.211, 95% CI: 2.040-5.054). Additionally, the longitudinal correlation between medial meniscus damage and progression of KOA (OR: 1.853, 95% CI: 1.177-2.941) and medial JSN (OR: 1.655, 95% CI: 1.053-2.602) was significant. Synovitis was found to mediate the relationship between medial meniscus extrusion and KL and medial JSN progression at baseline (ß: 0.029, 95% CI: 0.010-0.053; ß: 0.022, 95% CI: 0.005-0.046) and beyond 24 months (ß: 0.039, 95% CI: 0.016-0.068; ß: 0.047, 95% CI: 0.020-0.078). However, we did not find evidence of synovitis mediating the relationship between meniscal damage and KOA progression. Synovitis mediates the relationship between medial meniscus extrusion (rather than meniscus damage) and KOA progression.

Medial Meniscus Posterior Root Reconstruction and Open-Wedge High-Tibial Osteotomy for Medial Meniscus Posterior Root Tear With Varus Knee Alignment: A Retrospective Study on Short-Term Outcomes.

PURPOSE: We describe 13 cases of medial meniscus posterior root tear (MMPRT) with varus knee alignment treated with medial meniscus posterior root reconstruction (MMPR-R) and open-wedge high-tibial osteotomy (OWHTO) to identify an optimal MMPRT treatment. METHODS: We retrospectively reviewed 13 patients (mean age: 66.3 ± 8.0 years) who underwent MMPR-R and OWHTO. The Knee Injury and Osteoarthritis Outcome Score (KOOS), femorotibial angle (FTA), percentage mechanical axis (%MA) on radiography, and medial meniscus extrusion (MME) on magnetic resonance imaging (MRI) between the preoperative period and last follow-up were compared. Moreover, meniscus healing status and the International Cartilage Repair Society (ICRS) classification of the medial femoral condyle and medial tibial plateau on arthroscopy between the initial surgery and second-look arthroscopy were compared. RESULTS: The mean follow-up duration was 12.8 ± 2.2 months. At the last follow-up, the KOOS significantly improved (P < 0.01). Based on the FTA and %MA, the varus alignment was predominantly corrected at the last follow-up (P < 0.01). The MME was increased in nine (62.9%) patients, and the mean MME significantly increased at the last follow-up (P = 0.04). Second-look arthroscopy revealed improvements in the ICRS grade for the medial femoral condyle and medial tibial plateau in six (46.2%) patients. However, the results did not significantly differ. Regarding meniscus healing, four (30.8%) patients presented with complete healing, eight (57.1%) with partial healing, and one (7.7%) with failed healing. CONCLUSIONS: The MMPRT with varus knee alignment significantly improved with MMPR-R and OWHTO. However, the MME and meniscus healing were unsatisfactory.

Ramp-like lateral meniscus tear. Description of an infrequent lesion.

Numerous studies on meniscal tears have been published, a pathology that continues to evolve in terms of treatment and patient outcomes. As our understanding of anatomy and biomechanics improves, new entities have emerged. The lateral meniscus, especially its posterior attachment, tends to be overlooked due to its greater mobility compared to the medial meniscus. Evaluating the instability of the posterior horn poses a challenge, even during arthroscopy, therefore, it is crucial to understand the posterior menisco-synovial detachment lesions, which are indeed real and, to date, haven't received enough attention in the existing literature. The aim is to describe a new entity affecting the posterior synovial attachment of the lateral meniscus, without injury to the posterior horn of the lateral meniscus (PHLM). We also aim to present a case report detailing the intraoperative diagnosis and management of a 20-year-old patient with a sports trauma that led to a combined anterior cruciate ligament (ACL) and lateral meniscus tear managed with arthroscopic ACL reconstruction and all-inside meniscal suture. Through conventional arthroscopic evaluation of the posterior capsule anatomy and dissections, we have identified a distinct lesion of the PHLM at the menisco-synovial junction. Further research is necessary in this field to understand the biomechanical repercussions and determine the ideal surgical management.

Enhancing Muscle Strength Post Anterior Cruciate Ligament Reconstruction: A Case Report Assessing the Effectiveness of Russian Current.

The effectiveness of Russian electrical stimulation in enhancing muscular strength after anterior cruciate ligament (ACL) restoration is examined in this case study. In addition to traditional physiotherapy, a 29-year-old male athlete having ACL repair took part in a Russian contemporary rehabilitation regimen. Subjective evaluations of pain and functional tests all showed a substantial increase in muscular strength following the intervention. The Russian current's distinct waveform and high-frequency bursts appeared to improve neuromuscular control and quicken the activation of skeletal muscle in the excitation-contraction phase. The evaluation conducted after the intervention revealed notable enhancements in muscular strength and scores on the lower extremity functional scale. The initial score of 32, indicating a moderate functional limitation, improved to 64, indicating a minimal functional limitation. Additionally, the use of Russian electrical stimulation in ACL rehabilitation programs resulted in a reduction in pain levels from 9/10 to 3/10, as measured by the visual analog scale. These findings suggest that the implementation of Russian electrical stimulation shows promise in ACL rehabilitation. However, to validate and further explore these results, it is necessary to conduct larger-scale research studies and randomized controlled trials.

Photo-Polymerizable Autologous Growth-Factor Loaded Silk-Based Biomaterial-Inks toward 3D Printing-Based Regeneration of Meniscus Tears.

Meniscus tears in the avascular region undergoing partial or full meniscectomy lead to knee osteoarthritis and concurrent lifestyle hindrances in the young and aged alike. Here they reported ingenious photo-polymerizable autologous growth factor loaded 3D printed scaffolds to potentially treat meniscal defects . A shear-thinning photo-crosslinkable silk fibroin methacrylate-gelatin methacrylate-polyethylene glycol dimethacrylate biomaterial-ink is formulated and loaded with freeze-dried growth factor rich plasma (GFRP) . The biomaterial-ink exhibits optimal rheological properties and shape fidelity for 3D printing. Initial evaluation revealed that the 3D printed scaffolds mimic mechanical characteristics of meniscus, possess favourable porosity and swelling characteristics, and demonstrate sustained GFRP release. GFRP laden 3D scaffolds are screened with human neo-natal stem cells in vitro and biomaterial-ink comprising of 25 mg mL-1 of GFRP (GFRP25) is found to be amicable for meniscus tissue engineering. GFRP25 ink demonstrated rigorous rheological compliance, and printed constructs demonstrated long term degradability (>6 weeks), GFRP release (>5 weeks), and mechanical durability (3 weeks). GFRP25 scaffolds aided in proliferation of seeded human neo-natal stem cellsand their meniscus-specific fibrochondrogenic differentiation . GFRP25 constructs show amenable inflammatory response in vitro and in vivo. GFRP25 biomaterial-ink and printed GFRP25 scaffolds could be potential patient-specific treatment modalities for meniscal defects.

The Association between the Extent of the Osteoarthritic Meniscus Degeneration and Cigarette Smoking-A Pilot Study.

Background and Objectives: The negative effects of smoking on the musculoskeletal system were presented by many authors, although the relationship between smoking and osteoarthritis remains unclear. The aim of this paper was to investigate the negative effects of smoking on meniscal tissue in osteoarthritic knees by microscopic examination, by adapting the Bonar scoring system and its modifications. Materials and Methods: The study involved 34 patients with varus knees, from whom 65 samples of knee menisci were obtained. The mean age in the studied group was 65.385 years. The smoking status of the patients concluded that there were 13 smokers and 21 nonsmokers. Results: Among smokers, the mean classical Bonar score was 8.42 and the mean modified Bonar score was 6.65, while nonsmokers were characterized by scores of 8.51 and 7.35, respectively. There was a statistically significant negative correlation between the number of cigarettes and the collagen in the medial meniscus (p = 0.0197). Moreover, in the medial meniscus, the modified Bonar score correlated negatively with the number of cigarettes (p = 0.0180). Similarly, such a correlation was observed between the number of cigarettes and the modified Bonar score in the lateral meniscus (p = 0.04571). Furthermore, no correlation was identified between the number of cigarettes and the classical Bonar score in the lateral meniscus. There was a statistically significant difference in the collagen variable value between the smokers and nonsmokers groups (p = 0.04525). Conclusions: The microscopic investigation showed no differences in the menisci of smokers and nonsmokers, except for the collagen, which was more organized in smokers. Moreover, the modified Bonar score was correlated negatively with the number of cigarettes, which supports the role of neovascularization in meniscus pathology under the influence of tobacco smoking.

Artificial intelligence applied to magnetic resonance imaging reliably detects the presence, but not the location, of meniscus tears: a systematic review and meta-analysis.

OBJECTIVES: To review and compare the accuracy of convolutional neural networks (CNN) for the diagnosis of meniscal tears in the current literature and analyze the decision-making processes utilized by these CNN algorithms. MATERIALS AND METHODS: PubMed, MEDLINE, EMBASE, and Cochrane databases up to December 2022 were searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. Risk of analysis was used for all identified articles. Predictive performance values, including sensitivity and specificity, were extracted for quantitative analysis. The meta-analysis was divided between AI prediction models identifying the presence of meniscus tears and the location of meniscus tears. RESULTS: Eleven articles were included in the final review, with a total of 13,467 patients and 57,551 images. Heterogeneity was statistically significantly large for the sensitivity of the tear identification analysis (I2 = 79%). A higher level of accuracy was observed in identifying the presence of a meniscal tear over locating tears in specific regions of the meniscus (AUC, 0.939 vs 0.905). Pooled sensitivity and specificity were 0.87 (95% confidence interval (CI) 0.80-0.91) and 0.89 (95% CI 0.83-0.93) for meniscus tear identification and 0.88 (95% CI 0.82-0.91) and 0.84 (95% CI 0.81-0.85) for locating the tears. CONCLUSIONS: AI prediction models achieved favorable performance in the diagnosis, but not location, of meniscus tears. Further studies on the clinical utilities of deep learning should include standardized reporting, external validation, and full reports of the predictive performances of these models, with a view to localizing tears more accurately. CLINICAL RELEVANCE STATEMENT: Meniscus tears are hard to diagnose in the knee magnetic resonance images. AI prediction models may play an important role in improving the diagnostic accuracy of clinicians and radiologists. KEY POINTS: • Artificial intelligence (AI) provides great potential in improving the diagnosis of meniscus tears. • The pooled diagnostic performance for artificial intelligence (AI) in identifying meniscus tears was better (sensitivity 87%, specificity 89%) than locating the tears (sensitivity 88%, specificity 84%). • AI is good at confirming the diagnosis of meniscus tears, but future work is required to guide the management of the disease.

Non-operative Management of Acute Knee Injuries.

PURPOSE OF REVIEW: Acute knee injuries are commonly encountered in both the clinical and sideline setting and may be treated operatively or non-operatively. This article describes an evidence-based approach to non-operative acute knee injury. This includes history, physical exam, imaging, and initial management. In addition, the non-operative management of three such injuries-ligament injury, meniscus injury, and patellar dislocation injury-will be discussed via a case-based practical approach. RECENT FINDINGS: Aside from grade III ACL tears, most acute knee ligament injuries, especially in the absence of other concurrent injuries, can be treated non-operatively. There is new evidence that acute traumatic meniscus tears in those younger than 40 can be successfully treated non-operatively and can do equally, as well as those that undergo surgery, at 1 year out from injury. Based on the current literature, a short period of knee bracing in extension with progression to weightbearing to tolerance is recommended after initial patellar dislocation. Many of the most common acute knee injuries, including MCL tears, meniscus tears, and patellar dislocations, can be managed non-operatively. A detailed systemic approach to initial evaluation, including pertinent history, physical exam, and appropriate imaging, is essential and complementary to the subsequent non-operative treatment algorithm.

Radial and longitudinal meniscus tears show different gapping patterns under stance phase conditions.

Meniscal tearing can increase the contact pressure between the tibia and femur by causing gapping of torn meniscus tissue. The aim of this study was to quantify gapping behavior of radial and longitudinal tears and their impact on peak contact pressure and mean contact area. Twelve porcine knee joints underwent unicondylar, convertible osteotomy for exact tear application and consecutive suturing. Six tantalum marker beads were positioned along meniscus tears. The joints were preloaded with sinusoidal loading cycles ranging between 0 N and 350 N. Peak load was held constant and two synchronized Roentgen stereophotogrammetric analysis x-ray images were obtained to evaluate gapping, peak contact pressure and mean contact area in the native, torn and repaired states. There was no change in gapping or peak contact pressure in longitudinal tear. By contrast, the radial tear led to a significant gapping when compared to the native state, while the inside-out suture was able to restore gapping in parts of the meniscus. An increase in contact pressure after radial tear was detected, which was again normalized after suturing. The most important finding of the study is that longitudinal tears did not gap under pure axial loading, whereas radial tears tended to separate the tear interfaces.

Surgical Management of Traumatic Meniscus Injuries.

The menisci increase the contact area of load bearing in the knee and thus disperse the mechanical stress via their circumferential tensile fibers. Traumatic meniscus injuries cause mechanical symptoms in the knee, and are more prevalent amongst younger, more active patients, compared to degenerative tears amongst the elderly population. Traumatic meniscus tears typically result from the load-and-shear mechanism in the knee joint. The treatment depends on the size, location, and pattern of the tear. For non-repairable tears, partial or total meniscal resection decreases its tensile stress and increases joint contact stress, thus potentiating the risk of arthritis. A longitudinal vertical tear pattern at the peripheral third red-red zone leads to higher healing potential after repair. The postoperative rehabilitation protocols after repair range from immediate weight-bearing with no range of motion restrictions to non-weight bearing and delayed mobilization for weeks. Pediatric and adolescent patients may require special considerations due to their activity levels, or distinct pathologies such as a discoid meniscus. Further biomechanical and biologic evidence is needed to guide surgical management, postoperative rehabilitation protocols, and future technology applications for traumatic meniscus injuries.