Meniscal Ramp Lesions: Anatomy, Incidence, Diagnosis, and Treatment

Inside-Out Repair of Medial Meniscal Ramp Lesions in Patients Undergoing Anterior Cruciate Ligament Reconstruction

Background

Medial meniscal ramp lesions are disruptions at the meniscocapsular junction and/or meniscotibial attachment of the posterior horn of the medial meniscus, and occur in up to 42% of all acute anterior cruciate ligament (ACL) tears1,3-5. Ramp lesions are frequently missed because of the limited diagnostic sensitivity of magnetic resonance imaging (MRI), physical examination, and standard anterior compartment arthroscopic exploration4,6,7. Arthroscopic evaluation of ramp lesions often requires a modified Gillquist maneuver and/or a posteromedial accessory portal for adequate assessment of the posteromedial "blind spot."4,8-10 Clinically, ramp lesions are associated with increased preoperative anterior knee instability, which may increase the risk of ACL graft failure if left untreated6,13. Although long-term comparative data on ramp-repair techniques are limited, proper arthroscopic assessment and treatment is recommended for all patients with ramp lesions at the time of ACL reconstruction (ACLR)1-5. In the present video article, we demonstrate a systematic approach for the identification and assessment of ramp lesions and describe a mini-open inside-out arthroscopically assisted repair technique for unstable ramp lesions at the time of ACLR.

Description

(1) The patient is placed in the supine position, and a contralateral leg holder is utilized to create more working room on the medial side. (2) Standard diagnostic arthroscopy is performed through anteromedial and anterolateral portals. (3) Next, with the arthroscope in the anterolateral portal, the scope is advanced through the intercondylar notch with the knee in 30° of flexion in order to inspect the posterior horn of the medial meniscus. Probing is directed both over the superior aspect of the posterior horn to assess for tears, separation, and/or displacement of the meniscocapsular junction, and under the inferior aspect of the posterior horn to assess the integrity of the meniscotibial attachment. (4) After confirmation of a ramp tear, an open dissection is carried out through the sartorial fascia, with blunt dissection performed anterior to the medial gastrocnemius and above the semimembranosus to create the posteromedial surgical site. (5) A suture-shuttling device is utilized, and the corresponding cannula is placed into the anterolateral portal and directed toward the tear under arthroscopic visualization from the anteromedial portal. (6) Next, the first needle is passed through the meniscus, and the second is delivered through the adjacent capsule to create a vertical or oblique suture pattern. The needles are retrieved from the posteromedial surgical site and promptly cut, and the sutures are tied. (7) Multiple sutures, both above (femoral) and below (tibial) the meniscus, are placed 3 to 5 mm apart in a similar fashion. (8) On completion of the repair, the meniscocapsular junction is probed in order to confirm adequate stability with minimal translation of the medial meniscus.

Alternatives

In the setting of an ACL tear, surgical options for concomitant repair of an unstable ramp lesion include all-inside, inside-out, or hybrid techniques (i.e., outside-in, inside-in, and/or all-inside).

Rationale

Repair of ramp lesions using an inside-out technique restores preoperative excessive knee instability, which may decrease the risk of ACL graft failure. In addition, an inside-out ramp repair has a reported low secondary meniscectomy rate (2%), offers flexibility regarding the number and placement of the sutures, and creates a potentially stronger repair; however, this procedure is more technically challenging compared with other repair techniques6,10. All-inside ramp repairs have been reported to have higher secondary meniscectomy rates, ranging from 11% to 31%, because of the inability to repair the meniscotibial ligament from the anterior portals13,14. Suture hook repair using a posteromedial portal is becoming more popular and reportedly has a significantly lower secondary meniscectomy rate compared with all-inside techniques (19% compared with 30.6%)15.

Expected Outcomes

At a minimum of 2 years of follow-up, DePhillipo et al. reported similar clinical outcomes and return to sports for patients who underwent combined ACLR plus inside-out repair of ramp lesions (n = 50) compared with a matched cohort who underwent isolated ACLR (n = 50). Although the ACLR plus ramp lesion repair group had had significantly greater preoperative knee instability compared with the isolated ACLR group, there was no difference in postoperative instability between groups at an average of 2.8 years (range, 2 to 8 years) of follow-up6.

Important Tips

The exterior posteromedial incision should be facilitated by inside-out transillumination of the medial compartment and by palpation using an intra-articular probe at the medial aspect of the joint in order to avoid saphenous vein injury10.Two-thirds of the posteromedial incision should be distal to the joint line, with one-third proximal, because the suture needles often angle downwards as they exit the capsule10.The pes anserinus tendons should be retracted during the posteromedial dissection in order to avoid injury to the saphenous nerve (which lies posteromedial to the tendons)10.70° to 90° of flexion relaxes the hamstring and gastrocnemius, which improves visualization and aids in retrieval of the suture needles as they exit the posterior capsule10.Entering the anterolateral portal with the suture-delivery device decreases the risk of neurovascular damage and optimizes the direction of the needle10.After placement of the first needle, keep slight tension on the first suture to avoid inadvertent suture damage during advancement of the second needle10.Recent reports have suggested that ramp lesions can occur in isolation without ACL injury or accompanying isolated or combined posterior cruciate ligament (PCL) tears. Do not forget to assess for ramp lesions in these scenarios16.

Acronyms

ACL = anterior cruciate ligamentPCL = posterior cruciate ligamentMMBH = medial meniscus bucket-handleMRI = magnetic resonance imagingMFC = medial femoral condyleMTP = medial tibial plateauPMC = posteromedial capsuleMM = medial meniscusAT = adductor tuberclesMCL = superficial medial collateral ligamentSM = semimembranosusMGT = medial head of gastrocnemius tendonACLR = anterior cruciate ligament reconstructionPROMs = patient-reported outcome measuresMTL = meniscotibial ligament.

Approaching ramp lesions from the different world of posterior knee compartment: A review of evidence with a proposal of a new classification and treatment

Ramp lesions (RLs) are peripheral lesions that occur in the posterior part of the medial meniscus or where it attaches to the joint capsule. The classification of the medial meniscus RLs has been the focus of numerous studies and publications. This review provides an overview of RL's current classification and treatment options in anterior cruciate ligament deficient knees. The study also aims to present a more practical classification system for RLs to assist in treatment decision-making. For the first time, we also presented a new surgical treatment for incomplete inferior and double-complete RL based on the posterior knee arthroscopy that provides direct access to the posterior meniscal borders, enabling effective treatment and stronger biomechanical repair.

Level of Evidence

Level V.

Biomechanical impact of meniscal ramp lesions on knee joint contact characteristics in ACL deficient knees: a cadaveric analysis

PURPOSE

To evaluate the changes in contact characteristics of the tibiofemoral joint resulting from a meniscal ramp lesion in the medial meniscus.

METHODS

Twelve cadaveric knees (six matched pairs) were subjected to a 600 N axial load using a custom testing jig, which allowed for knee positioning at 0°, 45°, and 90° of flexion without other constraints. The knees were randomly assigned to either a ramp lesion group (n = 6) or a posterior root lesion group (n = 6). Four testing conditions were examined: (1) intact, (2) isolated ramp lesion, (3) isolated posterior root tear of the medial meniscus, and (4) combined ramp lesion and posterior root tear of the medial meniscus. Contact characteristics were evaluated using a flexible pressure sensor, the I-Scan System.

RESULTS

Peak contact pressure in isolated ramp lesions (4.15 ± 0.98 MPa, P = 0.206) showed non-significant increases compared to the intact condition (3.86 ± 1.32 MPa). Peak contact pressure in isolated posterior root tears (4.58 ± 1.70 MPa, P = 0.040) and, combined ramp and posterior root lesions (4.67 ± 1.47 MPa, P = 0.003) were significantly higher than that in the intact condition. The knee flexion position significantly affected the medial tibiofemoral joint's contact area, contact pressure, and peak contact pressure (P < 0.001 for all).

CONCLUSION

Isolated ramp lesions did not significantly impact force transmission, contact area, or contact pressure. In contrast, isolated root lesions and combined ramp and posterior root tears of the medial meniscus significantly intensified the changes in contact characteristics in the medial tibiofemoral joint compared to the intact condition.

LEVEL OF EVIDENCE

Level III.

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.

Magnetic resonance imaging shows low sensitivity but good specificity in detecting ramp lesions in children and adolescents with ACL injury: A systematic review

IMPORTANCE

The diagnosis of ramp lesions can be problematic, even with arthroscopy, due to their extreme posteromedial position. Consequently, they have been colloquially referred to as the "hidden lesions" of the knee. Undiagnosed and untreated injuries in this knee region may be associated with ongoing dynamic rotational laxity of the knee after anterior cruciate ligament reconstruction and an increased risk of anterior cruciate ligament graft failure.

AIM

This study aimed to systematically review the literature to assess the sensitivity, specificity and accuracy of magnetic resonance imaging (MRI) for detecting ramp lesions in children and adolescents with anterior cruciate ligament (ACL)-deficient knees. It was hypothesized that MRI has poor sensitivity for identifying ramp lesions in children and adolescents.

EVIDENCE REVIEW

A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following search terms were used in the title, abstract and keywords fields: "ramp" or "meniscus" AND "children" or "adolescents." The outcome data extracted from the studies were incidence of ramp in concomitant with ACL lesion, MRI sensitivity, specificity, accuracy and positive and negative predictive values (PPV and NPV).

FINDINGS

Of the 387 patients with ACL injury, 90 were reported to have ramp lesions (23.3%). The mean age at the time of diagnosis was 15.3 ​± ​0.81 years. The mean time from injury to MRI was 116.1 ​± ​113.5 days, while the mean time from injury to surgery was 172.6 ​± ​139.1 days. The MRI taken to detect ramp lesions in the paediatric population showed a pooled sensitivity of 50%, specificity of 75%, accuracy of 70%, PPV of 41% and NPV of 79%.

CONCLUSIONS AND RELEVANCE

The prevalence of ACL-associated ramp lesions in children and adolescents is similar to that in adult populations. Magnetic resonance imaging has low sensitivity but good specificity for assessing ramp lesions. In the presence of a posteromedial tibial bone bruise or a thin fluid signal separating the posterior horn of the medial meniscus and the posteromedial capsule a ramp lesion should always be suspected.

LEVEL OF EVIDENCE

Level IV.

STUDY REGISTRATION

PROSPERO -: CRD42023453895.

Reduced physiological extrusion of the medial meniscus in axial load-bearing condition in anterior cruciate ligament deficiency

PURPOSE

In this study, ultrasonography was used to measure medial meniscus (MM) extrusion under weight-bearing and nonweight-bearing conditions in both anterior cruciate ligament (ACL)-deficient and ACL-intact knee groups. This study aimed to determine the possible differences between these groups with an eventual impact on meniscal tears in ACL-deficient knees.

METHODS

A total of 107 patients who underwent ACL reconstructive surgery between June 2022 and April 2023 were enroled. After applying exclusion criteria, 37 patients met the conditions for inclusion in the study and formed the ACL deficiency group (Group D). Of the 141 patients presenting to an outpatient clinic who agreed to have ultrasonography conducted on their nondiscomforting contralateral knee, 37 patients matched for age, sex, hip-knee-ankle angle and body mass index with Group D patients were selected for the ACL intact group (Group I). Ultrasonography was used to measure MM extrusion in weight-bearing and nonweight-bearing conditions for all participants.

RESULTS

Seventy-four patients were included in the study (n = 37 per group). The supine position showed an MM extrusion of 1.2 ± 0.7 mm in Group I and 1.2 ± 0.7 mm in Group D (not significant). In the standing position, MM extrusion measured 2.0 ± 0.6 mm in Group I and 1.3 ± 0.8 mm in Group D. The difference in extrusion (Δextrusion) between the two positions was 0.8 ± 0.6 in Group I and 0.1 ± 0.2 in Group D, with statistical significance (p < 0.01). A consistent reduction in MM extrusion during weight-bearing was observed in patients with ACL deficiency, irrespective of the duration of ACL deficiency, age, sex and BMI.

CONCLUSION

ACL deficiency did not significantly impact MM extrusion during nonweight-bearing conditions; however, less MM extrusion was observed in response to axial loading conditions. These findings indicate altered MM biomechanics due to increased anterior-posterior meniscal motion and rotational instability after ACL injury.

LEVEL OF EVIDENCE

Level III.

Anterior Cruciate Ligament-Injured Knees With Meniscal Ramp Lesions Manifest Greater Anteroposterior and Rotatory Instability Compared With Isolated Anterior Cruciate Ligament-Injured Knees

PURPOSE

To investigate the effects of ramp lesion (RL) and its repair on knee instability in patients with anterior cruciate ligament (ACL) injury by quantitatively assessing anteroposterior and rotational knee instability before and after ACL reconstruction.

METHODS

All primary double-bundle ACL reconstructions using hamstring autografts between 2016 and 2021 were evaluated retrospectively. Patients with RLs without other meniscal injuries were included in group R, whereas those with isolated ACL injuries constituted group C. RL was repaired using all-inside devices in all patients in group R. Knee instability, including the amount of anterior tibial translation (ATT), and the acceleration and external rotational angular velocity of the knee joint (ERAV) during the pivot-shift test were assessed at the time of surgery. The pivot-shift test grade was recorded.

RESULTS

A total of 73 patients were included in this study. Preoperatively, group R (n = 23) had significantly greater pivot-shift grades (P = .039), ATT (6.0 mm, group R; 4.5 mm, group C, P < .001), acceleration (6.8, 2.8; P = .037), and ERAV (3.9, 2.8; P = .001) than group C (n = 50). Intraoperatively, ATT (-1.0 mm, -1.0 mm; P < .001), acceleration (1.2, 1.1; P < .001), and ERAV (1.4, 1.2; P < .001) were significantly decreased compared with the preoperative values in both groups. No significant differences in these values were observed between groups R and C.

CONCLUSIONS

ACL-injured knees accompanied by RLs exhibited significantly greater anteroposterior and rotatory instability than knees with isolated ACL injuries; increased knee instability can be effectively addressed by performing RL repair in conjunction with ACL reconstruction. The quantitative assessments employed-specifically measuring ATT, acceleration, and ERAV during the pivot-shift test-have allowed us to delineate these aspects of knee instability with greater precision.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective comparative study.

A New Entity of Ramp Lesion Combined with Posterior Root Tear of the Medial Meniscus: A Case Report

CASE

This report describes a new pattern of meniscal tear in an 18-year-old man after a knee sprain; he had undergone anterior cruciate ligament revision (ACL-R) 3 years earlier. He was diagnosed with an anterior cruciate ligament (ACL) graft rupture, a ramp lesion (Thaunat type 4), and a posterior root avulsion fracture of the medial meniscus (MM) (LaPrade type 5). He was treated successfully with an all-inside repair of the ramp lesion, a transtibial pull-out repair of the root tear, and ACL graft revision and anterolateral stabilization.

CONCLUSION

This specific meniscal injury pattern should be recognized and documented, potentially warranting consideration as a new addition to Thaunat and LaPrade classifications as type 6.

Meniscal Ramp Lesion Repair Without the Need for a Posteromedial Portal

Medial meniscal ramp injury has gained the attention of orthopaedic surgeons in recent years. It consists of a tear of the peripheral insertion of the posterior horn of the medial meniscus. Its prevalence in anterior cruciate ligament reconstruction varies between 9% and 40% according to different studies. Ramp lesions cannot always be diagnosed using magnetic resonance imaging scans. To identify ramp lesions, the arthroscope should be introduced into the posteromedial compartment of the knee during the routine examination of the knee (Gillquist maneuver). Not all authors advocate systematically repairing ramp injuries of the medial meniscus, especially when these injuries are small and stable. They have historically been repaired using an outside-in technique using a hook-type suture passed through a posteromedial portal. In this study, we present our all-inside suture technique without the use of a posteromedial portal.

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.

A Case Report on the Hidden Lesion of the Knee: Ramp Lesion

Introduction

Ramp lesions, often associated with anterior cruciate ligament (ACL) injuries, exhibit a varied incidence rate of 9-42%, increasing with delayed ACL reconstruction. These lesions, resulting from abnormal tibial movements and semimembranosus muscle contraction, are challenging to diagnose due to their hidden nature in standard magnetic resonance imaging and arthroscopy procedures.

Case Report

This report examines the case of a ramp lesion in the context of a multi-ligament injured knee of a 34-year-old male. The patient had a complete ACL, medial collateral ligament, and avulsion of the posterior cruciate ligament with a type 1 ramp lesion. These findings were confirmed by arthroscopy and were treated with arthroscopic reconstruction of the ligament and all inside repair of the ramp lesion. We report the pertinent imaging findings relevant to the ramp lesions.

Conclusion

Ramp lesions present a significant diagnostic and treatment challenge in orthopedic practice. Enhanced imaging techniques and a deeper understanding of their pathophysiology are crucial for an accurate diagnosis.

Extrusion and meniscal mobility evaluation in case of ramp lesion injury: a biomechanical feasibility study by 7T magnetic resonance imaging and digital volume correlation

Introduction: The existing body of literature on the biomechanical implications of ramp lesions is limited, leaving a significant gap in our understanding of how these lesions impact joint kinematics and loading in the medial compartment. This cadaveric biomechanical study aims to address this gap by employing an innovative Digital Volume Correlation (DVC) method, utilizing 7 Tesla Magnetic Resonance Imaging (MRI) images under various loading conditions. The primary objective is to conduct a comprehensive comparison of medial meniscal mobility between native knees and knees affected by grade 4 ramp lesions. By focusing on the intricate dynamics of meniscal mobility and extrusion, this work seeks to contribute valuable insights into the biomechanical consequences of medial meniscus ramp lesions. Materials and methods: An initial set of 7T MRI imaging sessions was conducted on two intact native knees, applying load values up to 1500N. Subsequently, a second series of images was captured on these identical knees, with the same loads applied, following the creation through arthroscopy of medial meniscus ramp lesions. The application of DVC enabled the precise determination of the three components of displacement and spatial variations in the medial menisci, both with and without ramp lesions. Results: The measured directional displacements between native knees and injured knees indicate that, following the application of axial compression load, menisci exhibit increased extrusion and posterior mobility as observed through DVC. Discussion: Injuries associated with Subtype 4 medial meniscus ramp lesions appear to elevate meniscal extrusion and posterior mobility during axial compression in the anterior cruciate ligament of intact knees. Following these preliminary results, we plan to expand our experimental approach to encompass individuals undergoing weight-bearing MRI. This expansion aims to identify meniscocapsular and/or meniscotibial insufficiency or rupture in patients, enabling us to proactively reduce the risk of osteoarthritic progression.

Influence of a posteromedial meniscocapsular injury on the knee anterior laxity. A cadaveric study

PURPOSE

The number of anterior cruciate ligament (ACL) injuries has considerably increased in the recent years, especially in young adults and adolescents. Associated meniscal tears increase anterior and rotary laxity. Posterior peripheral meniscocapsular tear of medial meniscus is also called ramp lesion. Prevalence of 9% to 17% in adults and up to 23% in pediatric population has been reported. The aim of this study was to determine anterior laxity of cadaveric ACL-deficient knees with several size of ramp lesions.

METHODS

Fresh cadaveric knees were explored. Major osteoarthritis and/or ACL and meniscal tears on arthroscopy were exclusion criteria. Mean age at death was 86 years old. Dynamic laximetry with GNRB® device was made in several conditions: Knee prior to any procedure, after arthroscopic exploration, after ACL section, and then after increasing sizes of ramp lesions up to 30 mm. Anteroposterior laxity was measured with 2 loading forces successively (134N and 200N).

RESULTS

After ACL section only, tibiofemoral joint anterior laxity was significantly increased. Mean increase was 156% regardless of the loading force. No statistical laxity difference was found between knees with ACL section only and knees with ACL and meniscal section for any size of ramp lesions. Increasing size of ramp lesion was not correlated with increasing of laxity.

CONCLUSION

We could not find a threshold size of ramp lesion which increases knee anterior laxity. We were not able to determine a threshold recommending a ramp lesion repair.

Evaluating the Reliability of YouTube as a Source of Information for Meniscal Ramp Lesions

Background

Videos uploaded to YouTube do not go through a review process, and therefore, videos related to medial meniscal ramp lesions may have little educational value.

Purpose

To assess the educational quality of YouTube videos regarding ramp lesions of the meniscus.

Study Design

Cross-sectional study.

Methods

A standard search was performed on the YouTube website using the following terms: "ramp lesion" and "posterior meniscal detachment" and "ramp" and "meniscocapsular" and "meniscotibial detachment," and the top 100 videos based on the number of views were included for analysis. The video duration, publication data, and number of likes and views were retrieved, and the videos were categorized based on video source (health professionals, orthopaedic company, private user), the type of information (anatomy, biomechanics, clinical examination, overview, radiologic, surgical technique), and video content (education, patient support, patient experience/testimony).The content analysis of the information on the videos was evaluated with the use of the DISCERN instrument (score range, 16-80), the Journal of the American Medical Association (JAMA) benchmark criteria (score range, 0-4), and the Global Quality Score (GQS; score range, 1-5).

Results

A total of 74 videos were included. Of these videos, 70 (94.6%) were published by health professionals, while the remaining 4 (5.4%) were published by orthopaedic companies. Most of the videos were about surgical technique (n = 36; 48.6%) and all had an educational aim (n = 74; 100%). The mean length of the videos was 10.35 ± 17.65 minutes, and the mean online period was 18.64 ± 13.85 months. The mean DISCERN score, JAMA benchmark score, and GQS were 31.84 ± 17.14 (range, 16-72), 1.65 ± 0.87 (range, 1-4), and 2.04 ± 1.21 (range, 1-5), respectively. Videos that reported an overview about ramp lesions were the best in terms of quality for DISCERN and JAMA benchmark score, while biomechanics videos were the best according to GQS. The worst category of videos was about surgical technique, with all having lower scores.

Conclusion

The educational content of YouTube regarding medial meniscal ramp lesions showed low quality and validity based on DISCERN score, JAMA benchmark score, and GQS.

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.

Medial meniscal posterior horn tears and ramp lesions in pediatric patients: lessons learned

Meniscal injuries are increasingly reported in pediatric patients due to early sports participation and are commonly encountered during anterior cruciate ligament reconstruction. Preoperative identification of meniscal tears is crucial, particularly when involving the posteromedial meniscocapsular junction (ramp lesion). MRI plays an important role in detecting this particular type of meniscal injury. Consequently, pediatric radiologists should be aware of particular MRI findings related to ramp lesions including the presence of a medial meniscal tear, peripheral meniscal irregularity, meniscocapsular junctional fluid-like signal intensity, and capsular ligament tears. Thus, we illustrate the lessons we have learned from our institutional multidisciplinary arthroscopic-MR correlation conference for retrospectively identified posterior horn medial meniscal tears and ramp lesions.

The Proportion of Meniscus Tears Considered Repairable, and Thus Repaired, Increased During a Single Surgeon's Practice of 20 Years

PURPOSE

The purpose of this study was to evaluate practice patterns of a single surgeon with respect to meniscectomy and meniscal repair over a 20-year period at a single institution.

METHODS

A cross-sectional descriptive study was carried out by reviewing the surgical data from the past 20 years (2002-2021) of patients who underwent arthroscopic primary meniscal surgery. Age, sex, knee and meniscus affected, morphology of the meniscal tear, meniscal radial location, location on the axial plane, tissue quality, and associated injuries were recorded. An analysis of the evolution of the characteristics of the meniscal lesions was performed according to the presence of degenerative tissue, the repairability of the lesion, and the treatment performed. Categorical data were represented in contingency tables and compared using the χ2 test for significance of differences, which was set at P < .05.

RESULTS

In total, 1,892 cases were included. A decrease in degenerative meniscal tears was found, from 63.2 in 2002 to 2006 to 9.7% in 2017 to 2021 (P < .001), while repairable tears increased from 1.6% to 82.3% P < .001); in the same periods, arthroscopic partial meniscectomy procedures declined from 75.7% to 17.7% (P < .001) while meniscal repair increased from 0.4% to 81.3% (P < .001). All types of tears increased significantly their repairability, although longitudinal tears, root tears, and ramp lesions showed the highest possibilities for repair.

CONCLUSIONS

In the present study, a drastic change in the attitude toward meniscal preservation in the past 20 years was observed, with a large increase in the proportion of tears considered repairable found in primary arthroscopic surgery (to 80% of cases) and a decrease in degenerative meniscus tears (to less than 10%).

CLINICAL RELEVANCE

In the past 2 decades, arthroscopic knee surgery has evolved such that more meniscus tears are deemed repairable, and fewer tears considered degenerative are indicated for arthroscopy.

Ramp lesion in anterior cruciate ligament injury: a review of the anatomy, biomechanics, epidemiology, and diagnosis

Ramp lesions, commonly observed in patients with anterior cruciate ligament (ACL) injuries, have been previously defined as longitudinal tears around the meniscocapsular junction. However, the definitions and interpretations of ramp lesions have varied, emphasizing the need to confirm their presence before surgery and the importance of direct visualization using arthroscopy. Recent histological studies have reported new findings on ramp lesions, shedding light on their attachment mechanisms. The anatomical structures around the ramp lesion, such as the posterior horn of medial meniscus (PHMM), semimembranosus (SM), posteromedial (PM) capsule, and meniscotibial ligament (MTL), were assessed regarding how these structures could be attached to each other. The studies of ramp lesions have also contributed to the progression of biomechanical studies explaining the cause and effects of ramp lesions. Ramp lesion has been proven to stabilize the anteroposterior (AP) instability of ACL. In addition, various laboratory studies have demonstrated the relationship between rotational instability of the knee joint and ramp lesions. The analysis of risk factors of ramp lesion helped to understand the injury mechanism of the lesion. Many authors have evaluated the prevalence of ramp lesions in patients with ACL injuries. The development of arthroscopy techniques has influenced the outcomes of ACL reconstruction with the easy detection of ramp lesions. This review article aims to analyze the past findings and recent advancements in anatomical, biomechanical, and epidemiological studies of ramp lesions in patients who underwent ACL reconstruction, and provide various perspectives ramp lesions in patients with ACL reconstruction.

Clinical and MRI Outcomes of Repaired Peripheral Longitudinal Tears of the Posterior Horn of the Medial Meniscus With ACL Reconstruction: Results According to Tear Size

Background

Arthroscopic repair of longitudinal tears in the medial meniscal posterior horn (MMPH) has been reported to result in high rates of meniscal healing when performed alongside anterior cruciate ligament reconstruction (ACLR). However, studies that have focused on longitudinal tears and their impact on clinical outcomes after arthroscopic repair are insufficient.

Purpose

To investigate the clinical outcome and healing status after concomitant arthroscopic ACLR and repair of MMPH peripheral longitudinal tears, with respect to the tear length.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 263 patients who underwent concurrent arthroscopic suture repair of longitudinal tears of the MMPH and ACLR were enrolled. All patients had 2-year postoperative magnetic resonance imaging (MRI) evaluations, and 61% of patients underwent a second-look arthroscopy. The exclusion criteria were partial meniscectomies and multiligament injuries. Patients were assessed pre- and postoperatively for clinical scores, amount of anterior translation, grade of pivot shift, and presence of meniscal tear extension. According to the length of longitudinal tears, patients were classified into 2 groups: (1) patients with tears that were located in the posterior compartment and (2) patients with tears that extended to the midbody of the meniscus. Binary stepwise logistic regression analysis was used to evaluate the risk factors for unhealed menisci as identified by MRI.

Results

A total of 83 patients were included in this study-52 patients (group 1) had MMPH tears without tear extension and 31 patients (group 2) had MMPH tears with tear extension. There were no differences in outcomes between the groups, including the healing rate after meniscal repair (P > .05). Based on postoperative MRI scans, 67 patients (80.7%) were categorized as completely healed and 16 patients (19.3%) as unhealed. There were no significant differences between the completely healed and unhealed groups in outcomes or the rate of preoperative midbody tear extension. Higher body mass index and lower preoperative Lysholm scores were identified as risk factors for unhealed menisci.

Conclusion

Overall, the rate of complete healing of MMPH tears repaired concomitantly with ACLR was 80.7% (67/83), and midbody tear extension did not affect the healing rate of the repaired meniscus. Results indicate that suture repair for unstable MMPH tears should be considered regardless of tear size.

Diagnosis by Manual Maneuver of Medial Meniscus Ramp Lesions

The intra-articular injury most often associated with a chronic anterior cruciate ligament tear involves the posterior horn of the medial meniscus. A specific type of medial meniscal injury, called a ramp lesion, has received greater attention for identification and treatment because of its considerable incidence and diagnostic difficulty. Based on their location, these lesions may be arthroscopically "hidden" during traditional anterior visualization. The purpose of the present Technical Note is to describe the Recife maneuver. This maneuver diagnoses injuries to the posterior horn of the medial meniscus using additional arthroscopic management through a standard portal. The Recife maneuver is performed with the patient in the supine position. A 30° arthroscope is inserted through the anterolateral portal, and the posteromedial compartment is accessed according to the transnotch view (modified Gillquist view). In the proposed maneuver, with the knee in 30° of flexion, a valgus stress with internal rotation is performed, followed by palpation of the popliteal region and digital pressure on the joint interline. This maneuver allows a greater visualization of the posterior compartment, allowing the diagnostic evaluation of the integrity between the meniscus and the capsule, in a safer way, being able to identify ramp tears without the need to create a posteromedial portal. We recommend that the addition of the diagnostic visualization step of the posteromedial compartment as described by the Recife maneuver be performed to assess the meniscal status in routine anterior cruciate ligament reconstruction.

Upsurge in publications on ramp lesions of the meniscus: A bibliometric study

PURPOSE

The purpose of this study was to analyze the trends in publications on ramp lesions of the meniscus in the current literature. We hypothesized that publications on ramp lesions have increased rapidly in recent years due to increased knowledge of both clinical and radiological pathology.

METHODS

A Scopus search performed on 21/01/23 retrieved 171 documents. A similar search strategy was employed to carry out a search for ramp lesions on PubMed with no time filters and only English articles. The articles were downloaded into Excel software, and citations for PubMed articles were determined from the iCite website. Analysis was performed using Excel. Using Orange software, data mining was performed from the titles of all articles.

RESULTS

There are a total of 126 publications from 2011 to 2022 with a total of 1778 citations in PubMed. Of all publications, 72% were published in the last 3 years, from 2020 to 2022, indicating an exponential increase in interest in this subject in recent years. Similarly, 62% of the citations were aggregated by the years 2017-2020, both years included. When the journals were analyzed according to the number of citations, the American Journal of Sports Medicine (AJSM) topped with 822 citations (46% of all citations) and 25 publications, followed by Knee Surgery, Sports Traumatology, Arthroscopy (KSSTA) with 27 articles and 388 citations (22% of all citations). When analyzed by citations per publication for different types of studies, randomized clinical trials (RCTs) were the most cited, with 32 citations per publication, followed by basic science articles with 31.5. Most of the basic science articles were cadaver studies examining anatomy, technique, and biomechanics. Technical notes were the third most cited at 18.64 per publication. While the USA is the country that leads publications, France is in a significant second position contributing to research on this topic, followed by Germany and Luxembourg.

CONCLUSIONS

Global trend analysis suggests that ramp lesion research has significantly increased and that the number of papers on the topic is steadily increasing. We found that the publications and citations presented a rising trend, the majority of the highly cited papers were contributed by a few centers, and the most cited were randomized clinical trials and basic science studies. The long-term outcomes of conservatively and surgically treated ramp lesions have attracted the most research interest.

Arthroscopic Ramp Repair: "No-Implant, Pass, Park, and Tie Technique" Using Knee Scorpion

Ramp lesions play a significant role in both anteroposterior and rotational knee stability. Ramp lesions are difficult to diagnose clinically as well as on magnetic resonance imaging. Arthroscopic identification by visualizing the posterior compartment and probing via the posteromedial portal will confirm the diagnosis of ramp lesion. Failure to address this lesion properly will lead to poor knee kinematics, residual knee laxity, and increased chances of failure of reconstructed anterior cruciate ligament. Here, we describe a simple arthroscopic surgical technique to repair ramp lesion, the pass, park, and tie at the end, via 2 posteromedial portals using a knee scorpion suture passing device.

Editorial Commentary: Arthroscopy Is the Gold Standard for Diagnosis of Meniscal Ramp Lesions: Magnetic Resonance Imaging Also May Be Helpful

Identifying and treating medial meniscal ramp lesions in conjunction with ligament reconstruction restores critical stability in knees with ligament injuries. This must begin with obtaining high-quality magnetic resonance imaging (MRI) and critical evaluation of the MRI and include a subsequent thorough arthroscopic examination of these knees. As evident in previous studies, most surgeons associate medial meniscal ramp lesions with anterior cruciate ligament (ACL) tears. Biomechanical studies have reported that a ramp lesion produces significant anterior tibial translation and external rotational instability in ACL-deficient knees that is not reestablished with an isolated ACL reconstruction. In addition, recent research identified ramp lesions in one-third of multiligament knee injuries with an intact ACL and two-thirds of patients with posteromedial tibial plateau bone bruises on MRI. Restoring knee stability and biomechanics is necessary in treating all knee ligament injuries. Don't miss the meniscal ramp lesion. Have a high index of suspicion, obtain a high-quality MRI,and arthroscopically evaluate the meniscocapsular junction of the medial meniscus, especially if there is a bone bruise seen on MRI.

Good results after treatment of RAMP lesions in association with ACL reconstruction: a systematic review

PURPOSE

This study aimed to systematically evaluate the clinical, functional, and radiological outcomes, complications, and rate of return to sports among patients with RAMP lesion of the medial meniscus encountered during anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic review was conducted based on the PRISMA guidelines. Two independent reviewers searched the PubMed, Scopus, Embase, and Cochrane Library databases using the terms "ACL" or "anterior cruciate ligament," and "RAMP lesion." The outcome measures extracted from the studies were the Short Form-12 (SF-12) in its mental and physical component (MCS and PCS), Lysholm score, Subjective IKDC, Marx Score, WOMAC Score, Tegner, Radiological changes, complications, failures and/or revision surgery, and rate of return to sports.

RESULTS

The cohort of patients consisted of 1,243 participants with a mean age of 28.6 ± 2.6. The mean postoperative follow-up was 40.9 ± 6.3 months. A total of 1145 (92.1%) RAMP lesions were repaired with concomitant ACL reconstruction, while only 98 (7.9%) lesions were left untreated (or treated with abrasion only). The Lysholm score was used in 6 studies (in one only at final follow-up), with a significant improvement in all the studies (Lysholm_pre 60.03 ± 6.12; Lysholm_post 89.9 ± 5.0). Eight studies out of nine reported Subjective IKDC score, and a significant improvement was noted in all cases (IKDC_pre 56.2 ± 5.8. IKDC_post 84.9 ± 3.7). Of 18 (1.4%) complications reported, 15 (1.2%) were related to RAMP/ACL surgery, and of the remaining three (0.2%) two (0.2%) were hematomas and one (0.1%) a contralateral ACL lesion. Of the 106 (8.5%) revision surgeries required, 5 (0.4%) were in non-treated lesions [two (0.2%) ACL re-ruptures and three (0.2%) medial meniscus re-injury]. In treated patients, the revision occurred for the following reasons: 75 (6.0%) meniscectomy, 14 (1.1%) meniscal suture revisions, 11 (0.9%) ACL failures and one (0.1%) arthrolysis.

CONCLUSIONS

It is not yet clear if, in all cases of ACL reconstruction in which a medial meniscal RAMP lesion is encountered, the lesion needs to undergo surgical repair. Accordingly, it is recommended that in the repair of all unstable medial meniscal RAMP lesions during an ACL reconstruction in cases associated with a stable RAMP lesion, the surgeon may decide on repair based on the patient profile.

LEVEL OF EVIDENCE

Level IV.

A novel mouse model of hindlimb joint contracture with 3D-printed casts

Stiff joints formed after trauma, surgery or immobilization are frustrating for surgeons, therapists and patients alike. Unfortunately, the study of contracture is limited by available animal model systems, which focus on the utilization of larger mammals and joint trauma. Here we describe a novel mouse-based model system for the generation of joint contracture using 3D-printed clamshell casts. With this model system we are able to generate both reversible and irreversible contractures of the knee and ankle. Four- or 8-month-old female mice were casted for either 2 or 3 weeks before liberation. All groups formed measurable contractures of the knee and ankle. Younger mice immobilized for less time formed reversible contractures of the knee and ankle. We were able to generate irreversible contracture with either longer immobilization time or the utilization of older mice. The contracture formation translated into differences in gait, which were detectable using the DigiGait® analysis system. This novel model system provides a higher throughput, lower cost and more powerful tool in studying the molecular and cellular mechanisms considering the large existing pool of transgenic/knockout murine strains.

Ramp Lesions in Chronic Anterior Cruciate Ligament Injuries

Background: Meniscus ramp lesions associated with anterior cruciate ligament (ACL) injuries are being increasingly reported in the literature. This study was carried out to know the incidence of ramp lesions in ACL injured patients and to study the characteristics of these patients in our population.

Methods: Seventy-five patients who underwent ACL reconstruction from January 2021 to December 2021 were prospectively studied. Patients with multi-ligament injuries or a history of previous knee surgery were excluded. All patients were examined clinically and all underwent MRI examinations. The findings of arthroscopy during ACL reconstruction were recorded and analyzed.

Result: Seventeen patients had ramp lesions with an incidence of 22.67%. Eight were isolated ramp lesions, and nine had other meniscus injuries. Ramp lesions were identified with 41.18% sensitivity using preoperative MRI. Thirteen out of 17 patients with ramp lesions had increased mobility of the posterior horn of the medial meniscus on anterior probing. The duration from injury to surgery was significantly longer in patients with ramp lesions as compared to patients without ramp lesions.

Conclusion: A ramp lesion is not an uncommon lesion in ACL injuries and can occur either as an isolated meniscus lesion or in association with other meniscus lesions.Ramp lesions can occur in road traffic accidents as well and are not just sports-related injuries. Ramp lesions are not visible through routine anterior portal diagnostic arthroscopy and their repair adds to the stability of the knee. The absence of ramp lesions on MRI does not rule out their presence; hence, one should always look for ramp lesions in the posteromedial compartment of the knee in all cases undergoing ACL reconstruction.

Suture Hook Versus All-Inside Repair for Longitudinal Tears of the Posterior Horn of the Medial Meniscus Concomitant to Anterior Cruciate Ligament Reconstruction: A Matched-Pair Analysis From the SANTI Study Group

BACKGROUND

Secondary meniscectomy rates after repair of longitudinal tears of the posterior horn of the medial meniscus (PHMM) performed concomitantly with anterior cruciate ligament reconstruction (ACLR) are reported to be as high as 25% with an all inside repair technique. Posteromedial portal suture hook repair is an emerging technique; however, it is unknown whether it confers a significantly reduced secondary meniscectomy rate compared with the current gold standard.

PURPOSE/HYPOTHESIS

The primary objective of this study was to compare the secondary meniscectomy rates of suture hook repair and all inside repair for longitudinal tears of the PHMM performed concomitant to ACLR. The secondary outcome was to determine the risk factors associated with the failure of the repair. It was hypothesized that repair with an all inside device would be associated with higher secondary meniscectomy rates when compared with suture hook repair and that concomitant anterolateral ligament reconstruction (ALLR) would confer improved meniscal repair survivorship.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients with longitudinal tears of the PHMM who underwent meniscal repair during primary ACLR between January 2011 and December 2015 at our institution were eligible for the study. Patients undergoing suture hook repair were propensity matched in a 1:1 ratio to patients who underwent all inside repair. At the end of the study period, secondary meniscectomy rates were determined.

RESULTS

The study population comprised 237 matched pairs. The mean follow up was 97.7 ± 17.3 months. Patients who underwent an all inside repair had a >2-fold higher failure rate compared with patients who underwent suture hook repair through a posteromedial portal (31.2% vs 15.6%; P = .0003). Patients in the suture hook repair group undergoing additional ALLR demonstrated a >3-fold higher meniscal repair survival rate compared with all other subgroups (P = .0014). This association was not seen in the all inside repair group. The only statistically significant risk factor for meniscal repair failure was the suture repair technique (hazard ratio, 2.133 [95% CI, 1.383-3.292]; P = .0008).

CONCLUSION

Suture hook repair through a posteromedial portal is associated with a significantly lower secondary meniscectomy rate when compared with the all inside meniscal repair of longitudinal tears of the PHMM performed at the time of ACLR. Furthermore, patients in the suture hook repair group who underwent an additional ALLR had a significantly better meniscal repair survivorship compared with all other subgroups.

Medial collateral ligament injury of the knee: correlations between MRI features and clinical gradings

OBJECTIVE

To evaluate the degree of correlation between MRI and clinical gradings of medial collateral ligament (MCL) injuries and assess for associated structures on MRI which may influence the clinical perception of MCL laxity.

MATERIALS AND METHODS

All knee MRIs with acute MCL injuries between 2016 and 2020 at our centre were retrospectively reviewed by two blinded musculoskeletal radiologists. The clinic notes were reviewed for clinical gradings.

RESULTS

One hundred and nineteen MRIs included. Forty-eight percent (57/119) agreement between MRI and clinical gradings (κ = 0.21, standard error (SE) 0.07). MRI grades: I 29% (34/119), II 50% (60/119), III 21% (25/119). Clinical grades: I 67% (80/119), II 26% (31/119), III 7% (8/119). In patients with clinical grade III MCL injury, there was waviness of the superficial MCL on MRI in 100% (8/8), deep meniscofemoral ligament tear in 75% (6/8), anterior cruciate ligament (ACL) partial or complete tear in 75% (6/8) and posteromedial corner (PMC) injury in 100% (8/8); compared with 0% (0/111), 34% (38/111), 44% (49/111) and 41% (46/111) respectively in clinical grade I or II injuries (p < 0.05).

CONCLUSION

Agreement between MRI and clinical gradings of MCL injuries was only 'fair', with MRI almost always overestimating the grade of the injury when there was a mismatch. Waviness of the superficial MCL and injuries to the deep MCL, ACL and PMC correlate with clinical instability.

Ramp lesion repair via dual posteromedial arthroscopic portals: A cadaveric feasibility study

BACKGROUND

Ramp lesions are found in 16% to 40% of patients undergoing anterior cruciate ligament reconstruction. The repair technique traditionally involves using a suture hook through a posteromedial portal, with the arthroscope positioned in the intercondylar view via an antero-lateral portal. Ramp lesions may be difficult to visualize and repair, even with a 70° arthroscope. The objective of this study was to assess the feasibility of suturing ramp lesions via dual posteromedial portals for the arthroscope and instruments.

HYPOTHESIS

Dual posteromedial arthroscopic portals allow good visualisation and high-quality suturing of ramp lesions, without inducing specific iatrogenic injuries.

MATERIAL AND METHODS

We used 11 fresh cadaver knees. Two posteromedial portals were created under visualisation via an arthroscope introduced through an antero-lateral portal: one was the traditional instrumental portal and the other, located more proximally, was the optical portal. A 2-cm long ramp lesion was created. A suture hook was used to place one or two stitches of PDS n°0 suture. A probe was used to test the quality and stability of the suturing. The posteromedial plane was then dissected to evaluate the anatomical relationships of the portals.

RESULTS

The dual posteromedial approach allowed the visualisation and hook suturing of the ramp lesions in all 11 cases. A single stitch was placed in 4 cases and two stitches in 7 cases. The suture was always of good quality and stable when tested with the probe. The dissection found no injuries to nerves, blood vessels, or tendons.

CONCLUSION

Ramp lesions can be repaired through a dual posteromedial arthroscopic approach. This surgical technique provides good visibility of these lesions and allows high-quality suturing, with no specific iatrogenic injuries. It is an alternative to ramp lesion repair via a single posteromedial portal, which can be challenging.

LEVEL OF EVIDENCE

IV, experimental study with no control group.

Meniscal Ramp Lesions: What the Radiologist Needs to Know

Meniscal ramp lesions are a special type of injury that affects the periphery of the posterior horn of the medial meniscus (PHMM) and/or its meniscocapsular attachments. They are strongly associated with acute and chronic anterior cruciate ligament (ACL) tears. These lesions have gained much prominence in recent years, due to a significant increase in their diagnosis and their important biomechanical involvement in the knee. It is known that their presence in ACL-deficient knees is related to instability and if they are not repaired during ACL reconstruction, they can ultimately cause the failure of the graft. Since this type of injury is often underdiagnosed due to its localization at the "blind" point of arthroscopic vision, it is crucial to make an accurate preoperative diagnosis of them with MRI. The objective of this article is to review the recent literature regarding meniscal ramp lesions and to summarize the anatomical, biomechanical and fundamentally diagnostic aspects, emphasizing the radiological findings described until now.

The accuracy of MRI for the diagnosis of ramp lesions

OBJECTIVES

To assess the diagnostic accuracy of MRI in diagnosing ramp lesions in patients with an acute lesion of the anterior cruciate ligament (ACL).

MATERIALS AND METHODS

All consecutive patients over 15 years of age who underwent surgical repair of the ACL at a single hospital between January and May 2019, with MRI data available, were included in this retrospective study, except patients who had previous knee surgery. The gold standard was arthroscopic evaluation. Two trained radiologists with 5 and 14 years of experience did a blinded review of the MRIs. The following pathological signs were studied: complete fluid filling between the capsule and the posterior horn of the medial meniscus, irregular appearance of the posterior wall of the medial meniscus, oedema of the capsule, fluid hyperintensity in contact with the medial meniscus and anterior subluxation of the medial meniscus. Logistic regressions in univariate then multivariate analysis were carried out and measures of diagnostic accuracy and interobserver agreement were calculated with R software (version 3.6).

RESULTS

Fifty-seven patients were included. Twelve had a ramp lesion diagnosed by arthroscopy (21%). Only complete fluid hyperintensity between the posterior horn of the medial meniscus and the capsule was significantly associated with ramp lesions (P value < 0.01). The diagnostic accuracy of this specific sign was moderate, with a specificity of 84%, sensitivity of 75%, PPV of 56%, NPV of 93% and a good level of inter-observer agreement (k = 0.79).

CONCLUSION

The complete fluid filling is the only significant pathological MRI sign for ramp lesions, with moderate accuracy.

Combined Meniscus Repair and Anterior Cruciate Ligament Reconstruction

Meniscal tear patterns associated with anterior cruciate ligament (ACL) tears, such as root tears and ramp lesions are common but less easily recognized on magnetic resonance imaging (MRI) compared with a complete radial tear or a locked bucket-handle tear. Timely treatment of these tears improves outcomes in the setting of ACL reconstruction. While physical examination does not enable a definitive diagnosis of meniscal root tears and ramp lesions, high-grade laxity, including a 3+ Lachman and 3+ pivot shift, should raise suspicions for these tear patterns. MRI allows visualization of both root tears and ramp lesions, although the gold standard for diagnosis is probing at the time of arthroscopy due to a high false-negative rate on MRI. Up to 17% of patients with an ACL tear have a lateral meniscal root tear; a contact mechanism and increased posterior slope are both associated with a greater incidence of lateral meniscal root tears and these are repaired with a tunnel technique. Meniscal ramp lesions occur in up to 41% of patients with ACL tears due to a contact mechanism, and we prefer repair with an inside-out technique. More than 60% of complete radial meniscal tears occur in the setting of ACL tears and are preferentially repaired with a hashtag technique for minimally separated tears and a 2-tunnel technique combined with an inside-out repair for more severe tears. Bucket-handle tears are more common in the setting of chronic ACL deficiency; concurrent with ACL reconstruction urgent meniscal repair with an inside-out technique is the gold standard, which allows for precise approximation of the tear with multiple points of fixation for improved biomechanical performance. It is critical to identify and treat these tears during ACL reconstruction because of their role as secondary stabilizers and for long-term chondral protection.

Incidência de lesões da rampa meniscal nas reconstruções do ligamento cruzado anterior

Objetivo Avaliar a incidência e o perfil epidemiológico das lesões da rampa meniscal nos pacientes submetidos a cirurgia de reconstrução do ligamento cruzado anterior (LCA), e determinar os fatores de risco relacionados.

Métodos Foram analisados retrospectivamente 824 pacientes submetidos a cirurgia de reconstrução do LCA. Os pacientes que apresentaram instabilidade meniscal medial foram submetidos a avaliação do compartimento posteromedial do joelho. Em caso de lesão, o reparo cirúrgico foi realizado. Potenciais fatores de risco associados às lesões foram analisados.

Resultados A incidência geral de lesões da rampa na população estudada foi de 10,6% (87 lesões em 824 pacientes). A análise multivariada pelo teste do Qui-quadrado demonstrou que a presença de lesões da rampa meniscal foi significativamente associada aos seguintes fatores de risco: lateralidade direita e lesões crônicas. Sexo, idade e atividade esportiva não foram estatisticamente significantes. O futebol foi a causa mais frequente de lesões da rampa relacionadas ao esporte, com 78,2% dos casos. No entanto, não se mostrou ser um fator de risco. De 2014 a 2019, a incidência anual variou de 4,0% a 20,6%.

Conclusão A incidência das lesões da rampa meniscal foi de 10,6% nas cirurgias de reconstrução do LCA, sendo mais frequente em pacientes com lesões crônicas. A incidência anual foi crescente, e variou de 4,0%, em 2014, a 20,6%, em 2019.

Meniscectomy is still a frequent orthopedic procedure: a pending need for education on the meniscus treatment possibilities

PURPOSE

The purpose of this study was to evaluate the current status of education of polish surgeons in the subject of meniscus repair possibilities. The analysis of the possible correlations between the number of knee arthroscopy procedures performed by polish surgeons and their decision whether to remove or to repair the damaged meniscus has been performed.

METHODS

Two-hundred and five registered orthopedic surgeons took part in surveys. The questionnaire contained the description of 20 patients with different types of meniscus damage and three questions concerning the experience in knee arthroscopy (two questions) and a choice of the treatment method (one question). Comparisons were made between knee arthroscopy experts (> 100 arthroscopies performed per year) and non-experts (≤ 100 cases).

RESULTS

The questionnaire was completed by 194 knee surgeons from Poland with different levels in knee arthroscopy experience. For most cases, experts and non-experts agreed on the meniscus treatment method. Statistically significant differences in the recommended treatment between experts and non-experts were observed in 4 cases, where experts decided to repair the damage rather than to perform the meniscectomy.

CONCLUSIONS

Meniscectomy remains a frequent orthopedic procedure, despite meniscal sparing having been advocated for several decades now and despite the existence of meniscus repair technique which gives good clinical outcomes-augmentation of the damaged meniscus with a collagen membrane. Polish surgeons still need education on the meniscus treatment possibilities.

LEVEL OF EVIDENCE

V.

Novel type of medial meniscus ramp lesion: a case report and surgical technique

Meniscal ramp lesions have been reported in 9-24% of patients who underwent anterior cruciate ligament reconstruction (ACLR). We report a rare type of double medial meniscus ramp lesion in in a 26-year-old male soccer player who presented with persistent knee instability and an inability to return to sports after a successful ACLR due to unaddressed and untreated ramp lesions. To the best of our knowledge, this is the first reported case of a double ramp lesion, with tears occurring in two separate locations: one tear at the meniscosynovial junction and associated with meniscotibial ligament disruption; and a second, more posteriorly located at the meniscocapsular junction and associated with meniscocapsular attachment disruption. It was found to be very unstable upon arthroscopic assessment and was clinically associated with persistent knee instability even after ACLR, thus necessitating surgical repair to restore knee kinematics.

A review of strategies for development of tissue engineered meniscal implants

The meniscus is a key stabilizing tissue of the knee that facilitates proper tracking and movement of the knee joint and absorbs stresses related to physical activity. This review article describes the biology, structure, and functions of the human knee meniscus, common tears and repair approaches, and current research and development approaches using modern methods to fabricate a scaffold or tissue engineered meniscal replacement. Meniscal tears are quite common, often resulting from sports or physical training, though injury can result without specific contact during normal physical activity such as bending or squatting. Meniscal injuries often require surgical intervention to repair, restore basic functionality and relieve pain, and severe damage may warrant reconstruction using allograft transplants or commercial implant devices. Ongoing research is attempting to develop alternative scaffold and tissue engineered devices using modern fabrication techniques including three-dimensional (3D) printing which can fabricate a patient-specific meniscus replacement. An ideal meniscal substitute should have mechanical properties that are close to that of natural human meniscus, and also be easily adapted for surgical procedures and fixation. A better understanding of the organization and structure of the meniscus as well as its potential points of failure will lead to improved design approaches to generate a suitable and functional replacement.

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

BACKGROUND

The posteromedial meniscal region is gaining interest among orthopedic surgeons, as lesions of this area has been reported to be significantly associated with anterior cruciate ligament tears. The current imaging literature is unclear.

PURPOSE

To evaluate the diagnostic performance of MR in the detection of meniscal ramp lesions having arthroscopy as reference standard.

MATERIALS AND METHODS

We retrospectively included 56 patients (mean age of 25 ± 7 years; 14 females) from January to November 2017 with a arthroscopically proved ACL tear and posterior meniscocapsular separation. On preoperative MRI, two radiologists with 13 and 2 years' experience in musculoskeletal imaging assessed the presence/absence of ramp lesion, meniscotibial ligament lesion, peripheral meniscal lesion, or their combination, bone bruise. Having arthroscopy as reference standard, diagnostic performance of MRI in the evaluation of ramp area lesions was calculated. Cohen's kappa (k) and Fisher's Exact Test statistics were used.

RESULTS

Agreement between radiologists ranged from κ = 0.784 (meniscotibial ligament lesions) to κ = 0.918 red-red meniscal lesion. Sensitivities were 97.4% for ramp lesions, 95.8% for meniscotibial ligament lesion, 94.4% for peripheral meniscal lesions; specificities were 88.9%, 81.3%, and 97.4%, respectively; accuracies were 94.6%, 87.5%, and 96.4%, respectively. Agreement between MR and arthroscopy was almost perfect in identification of ramp lesions (κ = 0.871) and red-red zone meniscal lesions (κ = 0.908). The agreement between the two methods was substantial (κ = 0.751) for meniscotibial lesion. No significant association between tibial plateau bone bruise and the different type of lesions was found (κ ≥ 0.004 and p ≥ 0.08).

CONCLUSION

MR has high diagnostic performance in meniscal ramp area lesion assessment, with substantial to almost perfect inter-reader agreement.

Ramp Lesion Subtypes: Prevalence, Imaging, and Arthroscopic Findings in 2156 Anterior Cruciate Ligament Reconstructions

BACKGROUND

Ramp lesions are defined as a particular type of injury within the posterior horn of the medial meniscus and its meniscocapsular attachments. Five subtypes have been described: type 1, meniscocapsular lesion; type 2, partial superior lesion; type 3, partial inferior lesion or hidden type; type 4, complete tear in the red zone; and type 5, complete double tear.

PURPOSE

(1) To determine the prevalence of different subtypes of ramp lesions in patients undergoing arthroscopic anterior cruciate ligament reconstruction (ACLR). (2) To describe the characteristics of ramp lesions based on imaging and diagnostic arthroscopy.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

All patients who underwent arthroscopic ACLRs between November 2015 and November 2018 by 2 senior surgeons at 1 institution were evaluated retrospectively (1) to describe the subtypes of ramp lesions diagnosed intraoperatively using transnotch arthroscopic exploration of the posteromedial compartment and (2) to look for any factors significantly associated with these subtypes. The following parameters were studied: demographics; history and clinical findings including time between injury and surgery, side-to-side laxity, and pivot shift; lesions missed on magnetic resonance imaging (MRI) scans and medial proximal tibial bone contusion visible on MRI scans; and arthroscopic confirmation of ramp lesion (ie, prevalence), associated lateral meniscal tear, or medial chondral tear.

RESULTS

Out of 2156 primary or revision arthroscopic reconstructions, 334 ramp lesions were confirmed, giving a prevalence of 15.5%. The subtype distribution was as follows: type 1, 47.9%; type 2, 4.8%; type 3, 11.4%; type 4, 28.7%; type 5, 7.2%. Multivariate analysis showed that gross pivot shift was significantly associated with complete ramp tears (odds ratio, 4.8; 95% CI, 1.7-17.2). Hidden lesions (type 3, inferior partial tear in the red zone) were the most likely to be missed on preoperative MRI (45.9%).

CONCLUSION

In a population undergoing ACLR, the prevalence of ramp lesions was 15.5%. Among the subtypes of ramp lesion, the most common was a meniscocapsular junction tear (type 1). Partial inferior tears (type 3) were the most likely to be missed on preoperative MRI scans. Gross pivot shift was significantly associated with complete ramp tears (types 1, 4, and 5).

[Relevance of meniscus loss for the progression of osteoarthritis and treatment options for early arthritis]

Meniscal tears are still one of the most frequent lesions in the knee joint. The relevance of meniscus loss for the development of osteoarthritis is undisputed. Meniscus repair, replacement and transplantation play an important role in the treatment of early arthritis, especially when they are a part of a master plan including alignment correction, stabilization and cartilage surgery, if needed. Scientific data show evidence concerning the protection of osteoarthritis, even though a lack of studies including comparison groups has to be admitted.

Meniscal ramp lesions: frequency, natural history, and the effect on knee cartilage over 2 years in subjects with anterior cruciate ligament tears

PURPOSE

(i) To investigate the frequency and natural evolution of meniscal ramp lesions (MRLs) on MRI in subjects with acute ACL tear and (ii) to compare knee cartilage compositional degeneration between subjects with MRLs and subjects without meniscal pathology over 2 years.

MATERIALS AND METHODS

Fifty-seven subjects with ACL tears (32 females; age 32.6 ± 8.3 years; BMI 24.5 ± 3.5 kg/m²) from a prospective study were screened for the presence of MRLs. Morphological (high-resolution 3D fast spin-echo) and compositional (T1ρ and T2 mapping) MRI was performed prior to and 2 years after ACL reconstruction. Follow-up MR images were assessed for changes in the signal intensity of the MRLs and the presence of meniscal tears. Differences of compositional parameters were compared between subjects with MRLs and without meniscal lesions using independent samples t tests.

RESULTS

MRLs were found in 16% (9/56) of the subjects with ACL tears at baseline. Only one subject with MRLs developed a posterior horn meniscal tear over 2 years. In 12 knees, no meniscal tears were found, which were defined as controls. Most interestingly, cartilage ∆T1ρ of the medial femur and medial tibia increased significantly more in subjects with MRLs compared with controls (mean difference, MF = 6.0 ± 0.8 vs. 2.3 ± 0.6, p = 0.004, and MT = 4.4 ± 1.4 vs. 0.4 ± 0.6, p = 0.027) and medial femur ∆T2 over 2 years increased significantly more in MRL than in control knees (5.1 ± 2.5 ms vs. 2.2 ± 1.9 ms, p = 0.012).

CONCLUSION

Subjects with ACL tear presented MRLs in 16% of cases. Compared with controls without meniscal lesions, knees with MRLs demonstrated accelerated degeneration of cartilage composition in the medial knee compartment over 2 years.

Inside-out Medial Meniscal Repair: Improved Surgical Exposure With a Sub-semimembranosus Approach

Inside-out meniscal repair is considered the gold standard for reparable tears of the medial and lateral menisci despite the recent popularity of all-inside devices. Accurate suture passage is required to perform a stable repair as well as to prevent inadvertent neurovascular injury from the suture needles. Placement of a deep soft-tissue retractor is necessary to identify and retrieve these needles prior to tying the sutures. Several authors have recommended placement of this retractor in the interval anterior to the gastrocnemius muscle belly and above the semimembranosus tendon. However, we have noted that the needles often pass distal to the retractor when it is placed in this interval owing to the reorientation of the joint line that occurs with the knee in a relatively extended position during suture placement. We describe a modified technique in which the retractor is placed inferior to the semimembranosus, which puts it directly in line with the needles' trajectory. This modification makes inside-out medial meniscal repair safer and more efficient.

MRI Criteria for Meniscal Ramp Lesions of the Knee in Children With Anterior Cruciate Ligament Tears

OBJECTIVE. The purpose of this study was to investigate the performance of MRI criteria for identifying meniscal ramp lesions in children with concomitant anterior cruciate ligament (ACL) tear, with arthroscopy used as the reference standard. MATERIALS AND METHODS. This retrospective study included 85 children who underwent a preoperative MRI examination and arthroscopically guided primary ACL reconstruction between June 1, 2017, and December 31, 2019. Blinded to arthroscopic findings, two radiologists reviewed all MRI examinations and reached consensus on the presence or absence of an effusion and various findings within the medial and lateral tibiofemoral joints. Chi-square, Fisher exact, independent t, and Mann-Whitney U tests were used to compare MRI findings between patients with and without arthroscopically confirmed meniscal ramp lesions. RESULTS. At arthroscopy, 35 children (23 boys and 12 girls; mean [± SD] age, 15.7 ± 2.0 years) had ramp lesions and 50 children (22 boys and 28 girls; mean age, 15.1 ± 2.4 years) had intact meniscocapsular junctions. Knees in which a ramp lesion was observed were significantly more likely to have MRI findings of a medial meniscus tear (p = .005), peripheral meniscal irregularity (p = .001), junctional T2-weighted signal (p < .001), and a meniscocapsular ligament tear (p < .001). No significant difference was found between children with and without ramp lesions with regard to the presence of an effusion (p = .65) or a lateral meniscus tear (p = .08) or the extent of medial and lateral tibial plateau marrow edema (p = .67 and p = .83, respectively). CONCLUSION. MRI findings associated with an arthroscopic diagnosis of meniscal ramp lesion include medial meniscus tear, peripheral meniscal irregularity, junctional fluidlike signal, and capsular ligament tear.

Is there a good agreement between MRI readers for Thaunat's classification in arthroscopically-proven meniscal ramp lesions?

OBJECTIVE

To describe and evaluate the reproducibility by MRI of an arthroscopically-based classification for meniscal ramp lesions. We hypothesize that MRI would present good interobserver and intraobserver reliability to evaluate meniscal ramp lesions.

MATERIALS AND METHODS

Twenty MRI of the knee with arthroscopically-proven meniscal ramp lesions were independently assessed by two skilled musculoskeletal radiologists and a third-year radiology resident. Reading was performed in a randomized and anonymous manner, in two steps, with a minimum of 1-month interval between each. Cohen's kappa coefficient statistic was used to analyze intra and interobserver reading agreement. Associate findings were also categorized.

RESULTS

From 20 subjects, 17 were male, with mean age of 35 years. MRI reading showed type IV ramp lesion as most prevalent with eight cases (37%), followed by type V - four (21%), type I - four (20%), type III - three, (16%) and type II - one (6%). Regarding ramp lesion types, intraobserver agreement was substantial for both skilled readers (Kappa = 0.72), and moderate for the less experienced reader (Kappa = 0.51); interobserver agreement was moderate. Results between most experienced readers were also analyzed in two categories: stable (types I and II) and unstable (types III, IV and V), also resulting in moderate agreement (Kappa = 0.54). Intraobserver agreement was substantial for both readers (Kappa = 0.68). The most common associate findings were joint effusion (85%), posteromedial capsular structures injury (60%), and medial meniscus extrusion (60%).

CONCLUSION

The arthroscopy classification for meniscal ramp lesions stability adapted for MRI has good reproducibility when applied by trained musculoskeletal radiologists.

Rationale and Surgical Technique of Ramp Lesion Repair Through an Additional Posteromedial Portal

Background:

Ramp lesions are longitudinal lesions of the meniscocapsular complex of the posterior horn of the medial meniscus. These lesions are poorly recognized, difficult to diagnose, and require specific arthroscopic exploration. Ramp lesions are typically associated with anterior cruciate ligament rupture and have important biomechanical consequences as they result in increased anterior tibial translation and external rotation. Suture hook repair through the posteromedial portal is safe and provides a high healing rate.

Indications:

Spontaneous healing of ramp lesions is rarely observed, and repair is indicated for all lesions with the involvement of meniscotibial ligament. The choice of a posteromedial repair technique with vertical suture performed under visual control allows restoration of the continuity of meniscotibial ligament and effective healing of these lesions.

Technique Description:

Standardized arthroscopic exploration with systematic visualization of the posteromedial compartment using the transnotch technique is a crucial point to diagnose these lesions. The use of transillumination and a needle allows to palpate the lesion with the tip of the needle in case of doubt (hidden lesion) before performing the posteromedial portal safely. By using the transnotch vision and by introducing the instruments through the posteromedial portal, debridement with the shaver and repair with the hook of the lesion are performed under visual control. Vertical repair is performed by taking care to pass the hook through the meniscotibial ligament by perforating the deep face of the capsular portion and anterior portion of the ramp lesion. Similarly, it is recommended not to catch too much meniscal tissue on the anterior margin side to remain in the red zone and not to perforate the meniscus in the avascular zone to avoid secondary lesions caused by the “cheese wire” effect of the sutures in the white zone.

Results:

This technique has allowed us to reduce our percentage of secondary meniscectomy after ramp lesion repair from 25% using a standard arthroscopic exploration and meniscal repair technique through the anterior portal to 11.3% using a arthroscopic exploration and repair technique through the posteromedial portal at 4 years of follow-up.

Discussion/Conclusion:

Systematic use of the transnotch vision and repair through the posteromedial portal are recommended for the management of these lesions, which demonstrate serious mechanical and clinical consequences.