Meniscal ramp lesions: diagnostic performance of MRI with arthroscopy as reference standard

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.

Meniscal ramp lesion classification systems: A systematic review

PURPOSE

To describe the proposed classification systems for meniscal ramp lesions (RLs) in the literature and evaluate their accuracy and reliability.

METHODS

A systematic search was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analyses guidelines utilising PubMed, Embase and Cochrane Library databases. Level I-IV studies referencing RLs along with either an arthroscopic- or magnetic resonance imaging (MRI)-based classification system used to describe RL subtypes were included.

RESULTS

In total, 21 clinical studies were included. Twenty-seven (79%) of the included studies were published in 2020 or later. There were four main classification systems proposed within the literature (two arthroscopic-, two MRI-based), describing tear patterns, mediolateral extent, associated ligament disruption and stability of the lesion. The first classification was proposed in 2015 by Thaunat et al. and is referenced in 22 (64.7%) of the included studies. The application of the Thaunat et al. criteria to MRI showed variable sensitivity (31.70%-93.8%) and interobserver agreement (k = 0.55-0.80). The Greif et al. modification to the Thaunat et al. system was referenced in 32.4% of the included studies and had a substantial interobserver agreement (k = 0.8). Stability to probing and specific tear location were each used to classify RLs in 28.6% and 23.8% of the included clinical studies, respectively.

CONCLUSION

Although there has been a recent increase in the recognition and treatment of meniscal RLs, there is limited consistency in descriptive classifications used for this pathology. Current RL classification systems based on preoperative MRI have variable reliability, and arthroscopic examination remains the gold standard for diagnosis and classification.

LEVEL OF EVIDENCE

Level IV.

Evaluating the Diagnostic Performance of MRI for Identification of Meniscal Ramp Lesions in ACL-Deficient Knees: A Systematic Review and Meta-Analysis

BACKGROUND

Despite vigorous efforts to delineate the efficacy of magnetic resonance imaging (MRI) for the diagnosis of meniscal ramp lesions, there is still a great deal of uncertainty regarding its diagnostic performance. Therefore, we conducted a systematic review and meta-analysis to investigate the diagnostic performance of MRI for detecting ramp lesions in anterior cruciate ligament (ACL)-deficient knees.

METHODS

We performed a systematic search of MEDLINE via PubMed, Scopus, Web of Science, and Embase and included all articles, published before October 20, 2022, comparing the accuracy of MRI with that of arthroscopy as the gold standard for diagnosis of ramp lesions. We performed statistical analysis using Stata and Meta-DiSc software. Quality assessment of the included studies was performed using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) tool.

RESULTS

This meta-analysis evaluated 21 diagnostic performance comparisons from 19 original research articles (2,149 patients). The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the summary receiver operating characteristic (SROC) curve for diagnosing a ramp lesion were 0.70 (95% confidence interval [Cl], 0.66 to 0.73), 0.88 (95% Cl, 0.86 to 0.89), 6.49 (95% Cl, 4.12 to 10.24), 0.36 (95% Cl, 0.28 to 0.46), 24.33 (95% Cl, 12.81 to 46.19), and 0.88, respectively. Meta-regression using different variables yielded the same results.

CONCLUSIONS

MRI exhibited a DOR of 24.33 and moderate sensitivity, specificity, and accuracy for diagnosing ramp lesions in ACL-deficient knees. However, arthroscopy using a standard anterolateral portal with intercondylar viewing is recommended to confirm a diagnosis of a ramp lesion.

LEVEL OF EVIDENCE

Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Posteromedial Corner Injuries of the Knee: Imaging Findings

The posteromedial corner (PMC) of the knee is an anatomical region formed by ligamentous structures (medial collateral ligament, posterior oblique ligament, oblique popliteal ligament), the semimembranosus tendon and its expansions, the posteromedial joint capsule, and the posterior horn of the medial meniscus. Injuries to the structures of the PMC frequently occur in acute knee trauma in association with other ligamentous or meniscal tears. The correct assessment of PMC injuries is crucial because the deficiency of these supporting structures can lead to anteromedial rotation instability or the failure of cruciate ligaments grafts. This article reviews the anatomy and biomechanics of the PMC to aid radiologists in identifying injuries potentially involving PMC components.

Editorial Commentary: A Gap-Based Subclassification of Ramp Lesions Has the Potential to Enhance Treatment Precision and Patient Outcomes in Anterior Cruciate Ligament-Deficient Knees Subtitle: Customizing Solutions for Anterior Cruciate Ligament-Deficient Knees

Our evolving understanding of ramp lesions has significantly affected the field of anterior cruciate ligament injury and meniscal repair. Although these lesions have been linked consistently to increased anterior and rotational instability in anterior cruciate ligament-deficient knees, there remains a contentious debate regarding their optimal treatment. The current literature is divided, as some advocate for surgical repair of only arthroscopically unstable lesions. Others point to a substantial risk of complications, noting a 28.6% incidence in untreated stable lesions, and thus advocate for surgical repair of all lesions. Through the use of magnetic resonance imaging scans of flexed knees, a novel subclassification of ramp lesions based on gap distance at the tear site shows a correlation with posterior capsular displacement, anterior laxity, lesion size, and joint effusion. This nuanced classification offers new insights and promises to refine treatment decisions, potentially minimizing unnecessary surgeries and improving patient outcomes.

Posteromedial tibial plateau bone bruises are associated with medial meniscal ramp lesions in patients with concomitant anterior cruciate ligament ruptures: a systematic review & meta-analysis

OBJECTIVE

To determine if posteromedial tibial plateau (PMTP) bone bruising on pre-operative MRI is significantly associated with a ramp lesion identified during arthroscopy in patients with concomitant ACL ruptures.

METHODS

PubMed, CINAHL, Scopus, Web of Sciences, EMBASE, and Cochrane Library were searched systematically for studies that investigated the association between PMTP bone bruises on preoperative MRI and ramp lesions confirmed during arthroscopy. Eight studies met inclusion criteria. The Methodological Index for Nonrandomized Studies (MINORS) checklist was used to assess quality. A meta-analysis was performed to analyze odds of a ramp lesion after PMTP bone bruising identified on magnetic resonance imaging (MRI). Publication bias was assessed by funnel plot and Egger's linear regression test.

RESULTS

There are 2.05 greater odds of medial meniscal ramp lesions in patients with an ACL rupture when PMTP bone bruising is found on preoperative MRI (95% CI, 1.29-3.25; p = 0.002). Heterogeneity of the pooled studies may be substantial (I2 = 65%; p = 0.006). Funnel plot analysis and Egger's linear regression test (p > 0.5) determined no publication bias among the studies included in the meta-analysis.

CONCLUSION

Patients with acute ACL injuries and PMTP bone bruising on MRI have 2.05 times greater odds of a concomitant medial meniscal ramp lesion than those without this bone bruise pattern.

Lateral-medial asymmetry of posterior tibial slope and small lateral tibial plateau articular surface depth are morphological factors of lateral meniscus posterior root tears in ACL-injured patients

PURPOSE

To investigate whether knee morphological features, patient characteristics, and intraoperative findings are associated with a lateral meniscus (LM) posterior root tear (LMPRT) in anterior cruciate ligament (ACL) injuries with the integrated data from two academic centres.

METHODS

This retrospective study used registry data acquired prospectively at two academic centres. Patients with ACL reconstruction (ACLR) with LMPRT and no other LM injury were selected (LMPRT group) from each database. The control group included patients who underwent ACLR without LM tears. Patients were matched to the LMPRT group according to age and gender (1:1). Morphological factors evaluated on preoperative magnetic resonance image scans included lateral femoral condyle (LFC) anterior-posterior diameter, height, and depth; lateral tibial plateau (LTP) articular surface (AS) depth and sagittal plane depth; and lateral and medial posterior tibial slopes (PTSs). LFC height and depth ratios, LTP AS depth and sagittal plane depth ratios, and lateral-to-medial slope asymmetry were computed from previous measurements. Patient characteristics and intraoperative findings were extracted and compared between both groups.

RESULTS

The study included 252 patients (126 in each group). The lateral-medial asymmetry of PTS was greater in the LMPRT group (1.2° vs 0.3°, p < 0.05), and the LTP AS depth was smaller in the LMPRT group (31.4 mm vs 33.2 mm, p < 0.01). There were no differences in LFC morphology between the control and LMPRT groups. Pivot shift grade (p < 0.05), percentage of complete ACL tears (p < 0.05), and medial meniscus ramp lesions (p < 0.05) were significantly higher in the LMPRT group.

CONCLUSION

LMPRT was associated with significantly increased lateral-medial asymmetry of PTS and significantly smaller LTP AS depth. LMPRT was also associated with an increase in the preoperative pivot shift grade and the presence of a medial meniscus ramp lesion. These morphological characteristics are rather simple to measure and would serve as helpful indicators to preoperatively detect LMPRT, which is frequently challenging to diagnose preoperatively.

LEVEL OF EVIDENCE

Level III.

Over One-Third of Patients With Multiligament Knee Injuries and an Intact Anterior Cruciate Ligament Demonstrate Medial Meniscal Ramp Lesions on Magnetic Resonance Imaging

PURPOSE

To determine the incidence of ramp lesions and posteromedial tibial plateau (PMTP) bone bruising on magnetic resonance imaging (MRI) in patients with multiligament knee injuries (MLKIs) and an intact anterior cruciate ligament (ACL).

METHODS

A retrospective review of consecutive patients surgically treated for MLKIs at 2 level I trauma centers between January 2001 and March 2021 was performed. Only MLKIs with an intact ACL that received MRI scans within 90 days of the injury were included. All MLKIs were diagnosed on MRI and confirmed with operative reports. Two musculoskeletal radiologists retrospectively rereviewed preoperative MRIs for evidence of medial meniscus ramp lesions (MMRLs) and PMTP bone bruises using previously established classification systems. Intraclass correlation coefficients were used to calculate the reliability between the radiologists. The incidence of MMRLs and PMTP bone bruises was quantified using descriptive statistics.

RESULTS

A total of 221 MLKIs were identified, of which 32 (14.5%) had an intact ACL (87.5% male; mean age of 29.9 ± 8.6 years) and were included. The most common MLKI pattern was combined injury to the posterior cruciate ligament and posterolateral corner (n = 27, 84.4%). PMTP bone bruises were observed in 12 of 32 (37.5%) patients. Similarly, MMRLs were diagnosed in 12 of 32 (37.5%) patients. A total of 8 of 12 (66.7%) patients with MMRLs demonstrated evidence PMTP bone bruising.

CONCLUSIONS

Over one-third of MLKI patients with an intact ACL were diagnosed with MMRLs on MRI in this series. PMTP bone bruising was observed in 66.7% of patients with MMRLs, suggesting that increased vigilance for identifying MMRLs at the time of ligament reconstruction should be practiced in patients with this bone bruising pattern.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Examining Preoperative MRI for Medial Meniscal Ramp Lesions in Patients Surgically Treated for Acute Grade 3 Combined Posterolateral Corner Knee Injury

Background

While medial meniscocapsular tears (ramp lesions) are commonly associated with isolated anterior cruciate ligament injuries, there are limited descriptions of these meniscal injuries in multiligament knee injuries (MLKIs).

Purpose

To (1) retrospectively evaluate preoperative magnetic resonance imaging (MRI) scans for the presence of ramp lesions in patients surgically treated for acute grade 3 combined posterolateral corner (PLC) knee injuries and (2) determine if a preoperative posteromedial tibial plateau (PMTP) bone bruise is associated with the presence of preoperative ramp lesions on MRI in these same patients.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Data on consecutive patients at a level 1 trauma center with MLKIs between 2001 and 2021 were retrospectively reviewed. Only patients with acute grade 3 combined PLC injuries who received an MRI scan within 30 days of injury were assessed. Two musculoskeletal radiologists retrospectively reviewed each patient's preoperative MRI for evidence of ramp lesions and bone bruises. Intraclass correlation coefficients (ICCs) were used to calculate reliability among the reviewers. Multivariate analysis was used to evaluate the relationship between PMTP bruising and the presence of a ramp lesion on MRI.

Results

A total of 68 patients (79.4% male; mean age, 33.8 ± 13.7 years) with an acute grade 3 combined PLC injury were included in the study. On MRI, the ICCs for detection of ramp lesions and PMTP bone bruising were 0.921 and 0.938, respectively. Medial meniscal ramp lesions were diagnosed in 18 of 68 (26.5%) patients. Eleven of 18 (61.1%) patients with ramp lesions also showed evidence of PMTP bruising, while 13 of 50 (26.0%) patients without ramp lesions had PMTP bruising (P = .008). When controlling for age and sex, PTMP bruising was significantly associated with the presence of a ramp lesion in combined PLC injuries (odds ratio, 4.62; P = .012).

Conclusion

Preoperative medial meniscal ramp lesions were diagnosed on MRI in 26.5% of patients with acute grade 3 combined PLC injuries. PMTP bone bruising was significantly associated with the presence of a ramp lesion on MRI. These findings reinforce the need to assess for potential ramp lesions at the time of multiligament reconstruction.

High prevalence of meniscal ramp lesions in anterior cruciate ligament injuries

PURPOSE

To evaluate the prevalence of and factors associated with meniscal ramp lesions on magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) injuries.

METHODS

Data from the Natural Corollaries and Recovery after ACL injury multicentre longitudinal cohort study (NACOX) were analysed. Only patients who underwent MRI were included in this study. All MRI scans were reviewed by an orthopaedic knee surgeon and a musculoskeletal radiologist. The patients were divided into two groups, those with and without ramp lesions according to MRI findings. Univariable and stepwise forward multiple logistic regression analyses were used to evaluate patient characteristics (age, gender, body mass index, pre-injury Tegner activity level, activity at injury) and concomitant injuries on MRI (lateral meniscus, medial collateral ligament [MCL], isolated deep MCL, lateral collateral ligament, pivot-shift-type bone bruising, posteromedial tibial [PMT] bone bruising, medial femoral condyle bone bruising, lateral femoral condyle [LFC] impaction and a Segond fracture) associated with the presence of meniscal ramp lesions.

RESULTS

A total of 253 patients (52.2% males) with a mean age of 25.4 ± 7.1 years were included. The overall prevalence of meniscal ramp lesions was 39.5% (100/253). Univariate analyses showed that contact sports at ACL injury, pivot-shift-type bone bruising, PMT bone bruising, LFC impaction and the presence of a Segond fracture increased the odds of having a meniscal ramp lesion. Stepwise forward multiple logistic regression analysis revealed that the presence of a meniscal ramp lesion was associated with contact sports at ACL injury [odds ratio (OR) 2.50; 95% confidence intervals (CI) 1.32-4.72; P = 0.005], pivot-shift-type bone bruising (OR 1.29; 95% CI 1.01-1.67; P = 0.04), PMT bone bruising (OR 4.62; 95% CI 2.61-8.19; P < 0.001) and the presence of a Segond fracture (OR 4.38; 95% CI 1.40-13.68; P = 0.001).

CONCLUSION

The overall prevalence of meniscal ramp lesions in patients with ACL injuries was high (39.5%). Contact sports at ACL injury, pivot-shift-type bone bruising, PMT bone bruising and the presence of a Segond fracture on MRI were associated with meniscal ramp lesions. Given their high prevalence, meniscal ramp lesions should be systematically searched for on MRI in patients with ACL injuries. Knowledge of the factors associated with meniscal ramp lesions may facilitate their diagnosis, raising surgeons' and radiologists' suspicion of these tears.

LEVEL OF EVIDENCE

III.

Multimodality Imaging Assessment of Desmoid Tumors: The Great Mime in the Era of Multidisciplinary Teams

Desmoid tumors (DTs), also known as desmoid fibromatosis or aggressive fibromatosis, are rare, locally invasive, non-metastatic soft tissue tumors. Although histological results represent the gold standard diagnosis, imaging represents the fundamental tool for the diagnosis of these tumors. Although histological analysis represents the gold standard for diagnosis, imaging represents the fundamental tool for the diagnosis of these tumors. DTs represent a challenge for the radiologist, being able to mimic different pathological conditions. A proper diagnosis is required to establish an adequate therapeutic approach. Multimodality imaging, including ultrasound (US), computed tomography (CT) and Magnetic Resonance Imaging (MRI), should be preferred. Different imaging techniques can also guide minimally invasive treatments and monitor their effectiveness. The purpose of this review is to describe the state-of-the-art multidisciplinary imaging of DTs; and its role in patient management.