Healing Status of Meniscal Ramp Lesion Affects Anterior Knee Stability After ACL Reconstruction

Secondary Restraints in ACL Reconstruction: State of the Art

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

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.

Risk factors and prevalence of ramp lesions in ACL ruptures: An analysis from the registry of the Francophone Arthroscopic Society

PURPOSE

The study aimed to estimate the prevalence of ramp lesions among patients undergoing anterior cruciate ligament (ACL) reconstruction and identify risk factors associated with these lesions.

METHODS

A retrospective, multicentre cohort study was conducted using data from the Francophone Arthroscopic Society's registry, including 5359 patients who underwent ACL reconstruction (ACLR) from June 2020 to June 2023. Potential risk factors for ramp lesion such as patient demographics, revision surgery, pivot shift, side-to-side anteroposterior laxity, medial collateral ligament (MCL) injury, lateral meniscal tear and the volume of ligament remnant were evaluated using multivariate regression analyses. BMI and delay to surgery were also assessed.

RESULTS

Ramp lesions were identified in 822 patients (15.3%). Univariate analysis identified male sex, younger age, revision surgery, lateral meniscal injury, percentage of ACL remnant (all p < 0.0001) and pivot shift (p = 0.0103) as significant risk factors. MCL injury was associated with a lower risk (p < 0.0001). In multivariate analysis, male sex, younger age, revision surgery, lateral meniscal injury and percentage of ACL remnants remained significant risk factors, while MCL injury remained a protective factor. The anteroposterior laxity wasn't a significant predictor in either analysis. In subgroup analysis, there were differences concerning body mass index (n.s) and the delay to surgery (n.s).

CONCLUSION

The study identified male sex, younger age, revision surgery, lateral meniscal injury and pourcentage of ACL remnant as significant risk factors for ramp lesions, with MCL injury acting as a protective factor. This will help regarding the suspicion and identification of ramp lesions.

LEVEL OF EVIDENCE

Level III.

Posterior Displacement of Meniscal Ramp Lesion Is Observed on Flexed Knee Magnetic Resonance Imaging of Anterior Cruciate Ligament-Deficient Knees

PURPOSE

To confirm whether posterior displacement of the detached meniscocapsular structure in ramp lesions could be observed on magnetic resonance imaging (MRI) in the flexed knee position and to clarify whether this displacement on MRI is related to greater anterior knee laxity.

METHODS

This retrospective comparative trial study included 50 patients with anterior cruciate ligament injuries in whom attendant ramp lesions were observed on preoperative MRI. All patients underwent 3-T MRI at 120° of knee flexion preoperatively. The gap distance of the ramp lesion on sagittal slices was measured, and a distance greater than 1 mm was classified as gap positive. Additionally, joint effusion in the posteromedial recess was quantitatively evaluated by measuring the surface area of joint fluid. Prior to surgery, the side-to-side difference in anterior tibial translation (ATT) on stress radiographs at 20° of knee flexion was measured to evaluate anterior knee laxity. During anterior cruciate ligament reconstruction, the length of the ramp lesion was measured by a scale from the posteromedial portal.

RESULTS

Of the 50 knees, 29 had ramp lesion gaps greater than 1 mm on MRI at knee flexion. The gap-positive group had a significantly greater side-to-side difference in ATT (9.6 ± 3.6 mm vs 5.0 ± 2.7 mm, P < .001) and significantly larger ramp lesion length (15.7 ± 4.9 mm vs 11.7 ± 3.9 mm, P = .002) than the gap-negative group. The gap-positive group also had a significantly greater amount of joint effusion than the gap-negative group (P < .001).

CONCLUSIONS

Posterior displacement of the detached meniscocapsular structure in ramp lesions can be observed on MRI at knee flexion and is related to greater anterior knee laxity, lesion size, and joint effusion.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

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.

Increased Intra-Articular Internal Tibial Rotation Is Associated With Unstable Medial Meniscus Ramp Lesions in ACL-Injured Athletes: An MRI Matched-Pair Comparative Study

Purpose

To analyze internal tibial rotation through magnetic resonance imaging (MRI) of patients with anterior cruciate ligament (ACL) injuries with and without an unstable medial meniscal ramp lesion (MMRL).

Methods

Retrospective analysis of prospectively data was performed to include all consecutive patients who underwent primary ACL reconstruction (ACLR) between January 2022 and June 2022. Two groups, ACLR + unstable MMRL and ACLR without MMRL, were constituted. Propensity score matching analysis was used to limit selection bias. The angle between surgical epicondylar axes (SEAs) and the tangent line of the posterior tibial condyles (PTCs) was measured to analyze the rotational alignment between distal femur and proximal tibia. MMRLs were defined unstable if they were ≥1 cm, if the lesions extend beyond the lower pole of the femoral condyle, and/or if there was displacement into the medial compartment by anterior probing.

Results

Twenty-eight propensity-matched pairs were included. The ACLR + unstable MMRL presented a significantly greater internal rotation of the tibia compared to ACLR without MMRL (P < .001). An internal tibial rotation was associated with unstable ramp lesions in ACL-injured patients (odds ratio [OR], 0.36; 95% CI, 0.25-0.41; P < .0001). If SEA-PTC was 0°, the sensitivity and specificity of the SEA-PTC angle to detect unstable MMRL were respectively 100% (95% CI, 85%-100%) and 18% (95% CI, 8%-36%). Otherwise, if SEA-PTC angle was -10°, the sensitivity and specificity of the SEA-PTC angle to detect unstable MMRL were respectively 43% (95% CI, 27%-61%) and 96% (95% CI, 81%-100%). Bone edema of the posterior medial tibial plateau was significantly associated with unstable ramp lesions (OR, 1.58; 95% CI, 1.21-2.06; P = .029).

Conclusions

Unstable MMRL concomitant to an ACL rupture was associated with an increased tibial internal rotation.

Level of Evidence

Level III, retrospective comparative trial.

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.

Medial meniscal lesions increase antero-posterior laxity in knees with anterior cruciate ligament injury

PURPOSE

The aim of this study was to quantify the impact of concomitant meniscal lesions on knee laxity using a triaxial accelerometer in a large population of patients affected by anterior cruciate ligament (ACL) injury.

METHODS

A total of 326 consecutive patients (261 men and 65 women, mean age 31.3 ± 11.3) undergoing primary ACL reconstruction, were preoperatively evaluated through Lachman and pivot shift tests using a triaxial accelerometer to quantify knee laxity. An analysis based on the presence of meniscal tears assessed during surgery was performed to evaluate the impact of meniscal lesions on knee laxity.

RESULTS

The anterior tibial translation (Lachman test) presented significantly higher values in patients with medial meniscal lesions (7.3 ± 1.7 mm, p = 0.049) and both medial and lateral meniscal lesions (7.7 ± 1.6 mm, p = 0.001) compared to patients without concomitant meniscal lesions (6.7 ± 1.3 mm). Moreover, patients with both medial and lateral meniscal lesions presented significantly higher values of anterior tibial translation compared to patients with lateral meniscal lesions (p = 0.049). No statistically significant differences were found between the groups in terms of tibial acceleration (pivot shift test).

CONCLUSION

This study demonstrated that the contribution of concomitant meniscal lesions to knee laxity can be objectively quantified using a triaxial accelerometer in ACL-injured knees. In particular, medial meniscus lesions, alone or in association with lateral meniscus lesions, determine a significant increase of the anterior tibial translation compared to knees without meniscus tears.

LEVEL OF EVIDENCE

Level IV.

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.

The effect of anterior cruciate ligament reconstruction and RAMP lesion repair on psychological status

BACKGROUND

There are few studies examining anterior cruciate ligament reconstruction (ACLR) and RAMP lesion repair. However, no studies have investigated the level of functional performance and psychological state after ACLR and all-inside RAMP lesion repair.

HYPOTHESIS/PURPOSE

The aim of this study is to determine the effect of ACLR and RAMP lesion repair on psychological status. ACLR and meniscal RAMP lesion repair were hypothesized to be associated with better psychological outcomes.

STUDY DESIGN

This is a cohort study.

METHODS

Patients who underwent ACLR with semitendinosus and gracilis autografts by a single surgeon were determined retrospectively. Fifteen patients who underwent ACLR and all-inside meniscus RAMP lesion repair (ACLR-RR) and 15 patients who underwent isolated ACLR were compared. Patients were evaluated by a physiotherapist at least 9 months after surgery. The primary outcome measure was anterior cruciate ligament-return to sports after injury (ACL-RSI), and the psychological status of the patients was examined. Secondary outcomes were visual analog scale (VAS), Tegner activity score, Lysholm knee score, single hop tests, and limb symmetry index (LSI). While pain intensity at rest and during movement was evaluated with VAS, functional performance level was evaluated with the Tegner activity score, the Lysholm knee score, single hop tests, and limb symmetry index (LSI).

RESULTS

A significant difference was found in the ACL-RSI values in the ACLR-RR group compared to the isolated ACLR group (p = 0.02). The results of the groups in VAS scores at rest and during movement, Tegner activity levels, and Lysholm knee scores, in the intact and operated leg single hop tests (single leg hop, cross hop, triple hop, and six-meter hop test), and the LSI values in the single leg hop tests showed no significant difference.

CONCLUSIONS

This study revealed different psychological outcomes and similar functional levels for ACLR and all-inside meniscus RAMP repair compared with isolated ACLR. It was observed that the psychological status of patients with RAMP lesions should also be evaluated.

Greater Knee Rotatory Instability After Posterior Meniscocapsular Injury Versus Anterolateral Ligament Injury: A Proposed Mechanism of High-Grade Pivot Shift

Background

For anterolateral rotatory instability as a result of secondary soft tissue injuries in anterior cruciate ligament (ACL)-deficient knees, there is increasing interest in secondary stabilizers to prevent internal rotation (IR) of the tibia.

Purpose

To determine which secondary stabilizer is more important in anterolateral rotatory instability in ACL-deficient knees.

Study Design

Controlled laboratory study.

Methods

The lower extremities of 10 fresh-frozen cadavers (20 extremities) without anterior-posterior or rotational instability were included. Matched-pair randomization was performed, with each side per specimen assigned to 1 of 2 groups. In group 1, the ACL was sectioned, followed by the anterolateral ligament (ALL); in group 2, the ACL was sectioned, followed by sequential sectioning of the posterolateral meniscocapsular complex (PLMCC) and posteromedial meniscocapsular complex (PMMCC). The primary outcome was the change in relative tibial IR during a simulated pivot-shift test with 5 N·m of IR torque and 8.9 N of valgus force. The secondary outcomes were the International Knee Documentation Committee grade in the pivot-shift test and the incidence of the grade 3 pivot shift.

Results

In group 1, compared with baseline, the change in relative tibial IR at 0° of knee flexion was 1.4° (95% CI, -0.1° to 2.9°; P = .052) after ALL release. In group 2, it was 2.5° (95% CI, 0.4° to 4.8°; P = .007) after PLMCC release and 4.1° (95% CI, 0.5° to 7.8°; P = .017) after combined PLMCC and PMMCC release. Combined PLMCC and PMMCC release resulted in greater change of tibial IR with statistical significance at 0°, 15°, and 30° of knee flexion (P = .008, .057, and .004, respectively) compared with ALL release. The incidence of grade 3 pivot shifts was 10% in group 1 and 90% in group 2.

Conclusion

Posterior meniscocapsular laxity caused an increase in relative tibial IR as much as ALL injury in ACL-deficient knees in our simulated laboratory test, and greater anterolateral rotatory instability occurred with posterior meniscocapsular injury compared with ALL injury.

Clinical Relevance

Repair of the injured posterior meniscocapsular complex may be an important treatment option for reducing anterolateral rotatory instability in the ACL-deficient knee.

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.

Searching for the Best Treatment for Ramp Lesions: A Systematic Review and Network Meta-Analysis

Ramp lesions are a common occurrence in patients with anterior cruciate ligament (ACL) tears. These lesions can be difficult to diagnose due to their concealed nature, and their treatment is crucial due to the stabilizing function of the medial meniscocapsular region. The optimal treatment option for ramp lesions varies depending on the size and stability of the lesion. The purpose of this study was to evaluate the best treatment option for ramp lesions based on the stability of the lesion, including no treatment, biological treatment, and arthroscopic repair. We hypothesize that stable lesions have a favorable prognosis with techniques that do not require the use of meniscal sutures. In contrast, unstable lesions require appropriate fixation, either through an anterior or posteromedial portal. This study is a systematic review and meta-analysis with a level of evidence IV. The study used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for a systematic review of clinical studies reporting outcomes of ramp lesion treatment. The PubMed/MEDLINE database was searched using Mesh and non-Mesh terms related to ramp lesions, medial meniscus ramp lesions, and meniscocapsular injuries. The inclusion criteria encompassed clinical studies in English or Spanish that reported the treatment of ramp meniscal lesions, with a follow-up of at least six months and inclusion of functional results, clinical stability tests, radiological evaluation, or arthroscopic second look. The analysis included 13 studies with 1614 patients. Five studies distinguished between stable and unstable ramp lesions using different criteria (displacement or size) for assessment. Of the stable lesions, 90 cases received no treatment, 64 cases were treated biologically (debridement, edge-curettage, or trephination), and 728 lesions were repaired. There were 221 repaired unstable lesions. All different methods of repair were registered. In stable lesions, three studies were included in a network meta-analysis. The best-estimated treatment for stable lesions was biological (SUCRA 0.9), followed by repair (SUCRA 0.6), and no treatment (SUCRA 0). In unstable lesions, seven studies using International Knee Documentation Committee Subjective Knee Form (IKDC) and 10 studies using Lysholm for functional outcomes showed significant improvement from preoperative to postoperative scores after repair, with no differences between repairing methods. We recommend simplifying the classification of ramp lesions as stable or unstable to determine treatment. Biological treatment is preferred for stable lesions rather than leaving them in situ. Unstable lesions, on the other hand, require repair, which has been associated with excellent functional outcomes and healing rates.

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.

American Academy of Orthopaedic Surgeons Clinical Practice Guideline Case Study: Management of Anterior Cruciate Ligament Injuries

Considering the frequency of anterior cruciate ligament (ACL) tears, optimal management of these injuries was the subject of a 2022 clinical practice guideline update from The American Academy of Orthopaedic Surgeons (AAOS) with input from representatives from the American Orthopaedic Society for Sports Medicine, the Pediatric Orthopaedic Society of North America, the American Orthopaedic Society for Sports Medicine, the American Medical Society for Sports Medicine, the American Academy of Physical Medicine and Rehabilitation, and the American College of Emergency Physicians. The eight recommendations and seven options to guide orthopaedic surgeons and other physicians managing patients with these anterior cruciate ligament injuries are based on the best current available evidence. The cases presented in this article are examples designed to demonstrate the clinical application of these guidelines.

Reproducibility of MRI in the diagnosis of meniscal ramp lesions: an inter-observer study

BACKGROUND

Meniscal ramp lesions have gained much prominence in recent years due to a significant increase in their diagnosis and their important biomechanical involvement in the knee. A new proposed classification of these lesions has recently been published.

PURPOSE

To evaluate the reproducibility of the new classification of meniscal ramp lesions recently published using magnetic resonance imaging (MRI).

MATERIAL AND METHODS

A total of 249 post-traumatic knee MRI studies were evaluated by three musculoskeletal radiologists independently. Patients with an anterior cruciate ligament (ACL) tear on MRI in addition to a recent history of trauma to the knee for <12 months were included in the study, for a total of 95. We carried out an inter-observer concordance study to analyze whether the new classification is reproducible to detect meniscal ramp lesions and to classify them into their different types.

RESULTS

Among our study cohort of 95 patients, we found 47 (49.5%) ramp lesions. In the inter-observer study, we obtained a good concordance (k = 0.733) in the detection of these lesions and an excellent one (k = 0.843) when the type of lesion is described.

CONCLUSION

This study demonstrates that the new classification of meniscal ramp lesions has good reproducibility 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.

Dual Posteromedial Portal Technique for Surgical Repair of an Unstable Medial Meniscal Ramp Lesion

Background:

Medial meniscal ramp lesions, which commonly occur in the setting of anterior cruciate ligament (ACL) ruptures, are defined as structural lesions at the medial meniscocapsular junction and can involve the posteromedial capsular attachments or most peripheral aspect of the meniscus. Unstable ramp lesions can lead to rotational instability within the knee and may play a role in ACL graft failure if left untreated. The novel use of dual posteromedial portals, similar to those used in an arthroscopic labral repair, may allow for enhanced visualization, optimal access to the posteromedial compartment, and easier manipulation of the instrumentation for successful surgical repair of hidden ramp lesions.

Indications:

Surgical repair of medial meniscal ramp lesions is indicated in patients with a clinically unstable meniscus when probed during arthroscopy.

Technique Description:

This surgical technique video demonstrates a dual posteromedial portal arthroscopic approach to repair an unstable medial meniscal ramp lesion using a case example from a patient with a concomitant ACL rupture.

Results:

Surgical repair of medial meniscal ramp lesions has been reported to show improvements in meniscus healing and knee stability.

Discussion/Conclusion:

The use of dual posteromedial portals offers improved accessibility to the posteromedial compartment of the knee and provides excellent visibility during the surgical repair of a medial meniscal ramp lesion. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Long-term Natural History of Unrepaired Stable Ramp Lesions: A Retrospective Analysis of 28 Patients With a Minimum Follow-up of 20 Years

BACKGROUND

There is a lack of consensus about whether stable ramp lesions associated with anterior cruciate ligament (ACL) injuries need to be repaired.

PURPOSE/HYPOTHESIS

The purpose of this study was to evaluate how many stable ramp lesions left in situ during ACL reconstruction (ACLR) have subsequently failed after >20 years of follow-up. We hypothesized that ACL-reconstructed knees with ramp lesions left in situ without repair have a high risk of meniscal failure over the long term.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients who underwent arthroscopic ACLR by a single experienced surgeon between January 1998 and December 2000 were evaluated retrospectively. Included were all cases of longitudinal tears in the meniscocapsular junction or the red zone of the posterior horn of the medial meniscus that were left in situ and identified through the anterior portals. Successful anterior probing confirmed a meniscal tear of the posterior segment. A lesion was considered stable if it was ≤2 cm and did not extend beyond the lower pole of the femoral condyle. The following data were collected preoperatively and at the last follow-up: demographics, time to surgery, side-to-side laxity, pivot shift, Lysholm score, subjective International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Tegner activity scale, and meniscal failure rate. We defined 2 groups based on our findings: medial meniscal failure versus no medial meniscal failure.

RESULTS

A total of 716 knees underwent primary ACLR during this period. The 39 (5.4%) stable unrepaired ramp lesions identified were included in the case series. Mean ± standard deviation follow-up was 262.1 ± 10.5 months. Eleven patients (28%) were lost to follow-up. Of the remaining patients, 8 (28.6%) had a medial meniscal failure, of which 6 (21.4%) were bucket-handle tears. The average time elapsed before complications was 87.8 ± 52 months (range, 6-156 months). The medial meniscal survival rate was 93% at 5 years, 75% at 10 years, and 71% at 15 and 20 years. The failure event mainly happened between 96 and 120 months (8 and 10 years) after ACLR. No risk factors for failure were found, but some trends appeared, such as older age, higher body mass index, and preoperative rotational instability. All postoperative scores were significantly improved at the last follow-up (P < .0001); 16 patients (57%) returned to their sport of choice.

CONCLUSION

With nearly one-third of patients developing meniscal complications, including a large share of bucket-handle tears and mostly occurring 8 years after the ACLR, it may not be wise to leave stable ramp lesions unrepaired.

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.

The crevice sign: a new indicator of meniscal instability in ACL reconstructions

PURPOSE

Meniscus preservation is key in knee surgery. The newly documented crevice sign indicates instability of the medial meniscus in ACL-deficient knees. Once the sign is visualised, it is imperative that the stability of the medial meniscus is assessed and potentially treated. It was hypothesized that there would be a strong correlation between the presence of an unstable medial meniscal tear in patients with the crevice sign in ACL-deficient knees.

METHODS

This was a multicenter prospective study carried out to evaluate the incidence of medial meniscal tears in patients with ACL-deficient knees and their correlation with a crevice sign. All patients (128) who had undergone ACL reconstruction between May 2020 and November 2020 were assessed arthroscopically for meniscal stability and divided in to two groups: stable (n = 84) and unstable (n = 44). Thereafter, the presence of the crevice sign was determined in each case.

RESULTS

The populations were comparable in terms of sex and age (Table 1). Fisher's exact test showed a significant association between the presence of the crevice sign and the instability of the medial meniscus (p < 0.001). Descriptive statistics suggest that the presence of crevice sign was associated more frequently to MM instability (38.6% vs 1.2%; p < 0.001). The specificity of this test was 98.8% and its sensitivity was 38.6%. The positive predictive value (PPV) was 94.4% and the negative predictive value (NPV) was 75.5%. Table 1 Descriptions and comparisons of internal meniscus instability of patients by presence of crevice sign Internal meniscus instability (N = 44) Internal meniscus stability (N = 84) Total (N = 128) Gender  N 44 84 128   Male 33 (75.0) 58 (69.0) 91 (71.1)   Female 11 (25.0) 26 (31.0) 37 (28.9) Fisher's exact test (n.s.) Age (years)  N 44 84 128   Mean (ET) 28.6 (9.4) 30.1 (10.2) 29.6 (9.9)   Median (IIQ) 26.5 (22.0;34.5) 27.0 (22.5;37.0) 27.0 (22.0;36.0)   [Min-Max] [14-54] [14-52] [14-54] Wilcoxon test bilateral (n.s.) Crevice sign  N 44 84 128   Absent 27 (61.4) 83 (98.8) 110 (85.9)   Present 17 (38.6) 1 (1.2) 18 (14.1) Fisher's exact test p < 0.001 CONCLUSION: The hypothesis was confirmed since medial meniscal instability was strongly correlated with the existence of the crevice sign and showed high specificity and PPV.

LEVEL OF EVIDENCE

III.

Short-Term Outcomes After Treatment of Isolated Hidden Meniscal Ramp Lesions

Background:

Ramp lesions are encountered in 16% to 24% of all anterior cruciate ligament (ACL) ruptures. However, isolated ramp lesions without a ruptured ACL have also been reported.

Purpose:

To evaluate outcomes after type 3 hidden ramp lesions without ACL rupture were treated with all-inside sutures passed through the standard anterior portal.

Study Design:

Case series, Level of evidence, 4.

Methods:

Included were 41 patients (26 female; 63.4%) with isolated type 3 ramp lesions who underwent surgery between January 2017 and January 2019. Patients with concomitant lateral meniscal injuries and revision meniscal surgeries were excluded. We retrospectively recorded patient age, sex, and body mass index (BMI), as well as follow-up periods, comorbidities, and postoperative and early midterm complications. The Lysholm, visual analog scale (VAS) for pain, and International Knee Documentation Committee (IKDC) scores were compared preoperatively to final follow-up. In addition, patients were classified as having either a sedentary or active lifestyle according to Sedentary Behavior Research Network (SBRN) criteria. The Shapiro-Wilk test was used to evaluate the normality of the data, and the Wilcoxon and Mann-Whitney U tests were used to compare preoperative and postoperative outcome scores. The Spearman test was employed to evaluate the correlation between patient variables.

Results:

The mean follow-up period was at 37.6 (range, 25-49) months. A total of 17 patients (41.46%) had a sedentary lifestyle based on SBRN criteria. All scores improved significantly from preoperatively to final follow-up (VAS, from 8.43 ± 1.53 to 2.34 ± 2.9; Lysholm, from 47.73 ± 17.02 to 85.37 ± 14.01; and IKDC, from 27.12 ± 14.81 to 85.32 ± 8.78; P < .001 for all). Although no significant relationship was established between patient activity level and postoperative Lysholm and IKDC scores, an inverse correlation was observed between BMI and Lysholm (r =–0.9906) and BMI and IKDC (r =–0.9402).

Conclusion:

Satisfactory postoperative clinical results were obtained in patients with type 3 ramp lesions not accompanied by ACL rupture who were treated with all-inside suturing through standard anterior portals.

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

Injuries to the medial meniscus meniscocapsular junction, also known as ramp lesions, are common in the setting of anterior cruciate ligament injuries with a prevalence of 9% to 42%. Anatomically, ramp lesions involve disruption of the posterior meniscocapsular junction and meniscotibial ligaments. Biomechanically, ramp lesions are associated with an increase in anterior tibial translation and internal and external tibial rotation in anterior cruciate ligament-deficient cadaveric knees. Magnetic resonance imaging is useful in evaluating the meniscocapsular junction. Irregularity or increased signal near the posterior meniscocapsular junction and/or signal change indicative of posterior medial tibial plateau edema can suggest these injuries are present before surgical intervention. The current benchmark for diagnosis is arthroscopic visualization of the posterior medial meniscocapsular junction viewed through the intercondylar notch. Once a ramp lesion is identified, stability should be assessed by arthroscopic probing to determine the degree of anterior displacement. Optimal treatment has been debated in the literature, especially for stable ramp lesions, although good outcomes have been shown with and without repair. Repair is warranted for those lesions that are unstable to probing. Unfortunately, only limited literature available to guide clinicians on the optimal rehabilitation for ramp lesions.

Leaving the stable ramp lesion unrepaired does not negatively affect clinical and functional outcomes as well as return to sports rates after ACL reconstruction

PURPOSE

To evaluate the effects of untreated stable ramp lesions on clinical and functional outcomes, return to sports rates, and complications of patients who underwent anterior cruciate ligament reconstruction.

METHODS

A total of 879 patients with anterior cruciate ligament rupture were evaluated. Of these, 66 patients [33 patients with anterior cruciate ligament rupture and stable medial meniscal ramp lesion (ramp + group) and 33 patients with isolated anterior cruciate ligament rupture (ramp - group)] with a minimum 3-year of follow-up were included. Stable ramp lesions were not repaired in the ramp + group. Preoperative and postoperative Lachman and pivot-shift grades, Lysholm knee scores, International Knee Documentation Committee score and 12-Item Short Form Health Survey score were compared between groups. The return to sports rates, level of return to sports, time to return to sports and complications were compared.

RESULTS

The mean patient age was 27.8 ± 7.2 years. The mean follow-up period was 47.3 ± 9.4 months. There were no significant differences between groups regarding preoperative and postoperative Lachman and pivot-shift grades, 12-Item Short Form Health Survey mental and physical component summary scores, Lysholm and International Knee Documentation Committee scores, and complication rates (n.s.). Although the return to sports rates (84.8% vs 90.1%) and the level of the return to sports (return to preinjury level: 75% vs 78%) were similar between groups (n.s.), the time to return to sports was significantly longer for patients with ramp lesions (11.1 ± 4.0 vs. 8.7 ± 2.5 months, p = 0.007).

CONCLUSION

Leaving the stable ramp lesion unrepaired does not negatively affect clinical and functional outcomes as well as return to sports rates after ACL reconstruction. However, the time to return to sports is prolonged in patients with ramp lesions In clinical practice, surgeons should be aware that repairing stable ramp lesions is not an absolute necessity and will not affect return to sport rates.

LEVEL OF EVIDENCE

Level III.

Ramp lesion of the medial meniscus

Ramp lesion of the medial meniscus used to be completely disregarded in the past.

Ramp lesion has been now put under the spotlight by orthopaedic and sport medicine surgeons and requires attention.

It is closely associated with anterior cruciate ligament injury. Major risk factors include chronic laxity, lateral meniscal lesion, anterior cruciate ligament reconstruction revision, anterolateral ligament tear concomitant with anterior cruciate ligament injury, time from injury, pre-operative side-to-side laxity > 6 mm, age < 30 years old, male sex, etc.

Radiologists attempt to create diagnostic criteria for ramp lesion using magnetic resonance imaging. However, the only definite method to diagnose ramp lesion is still arthroscopy. Various techniques exist, among which posteromedial approach is the most highly recommended.

Various treatment options are available. The success rate of ramp repair is very high. Major complications are uncommon.

Cite this article: EFORT Open Rev 2021;6:372-379. DOI: 10.1302/2058-5241.6.200126

Medial Meniscal Ramp Lesion Repair Through Anterior Portals Using a Medial Collateral Ligament Pie-Crusting Technique

Ramp injury, that is, injury to the peripheral attachment of the posterior horn of the medial meniscus, often requires additional surgery during anterior cruciate ligament (ACL) reconstruction. Diagnosis and treatment of ramp lesions are important because unrepaired ramp lesions could cause risk to the reconstructed ACL because of anteroposterior and external rotation laxity, whereas acute rupture or chronic deficiency of the ACL could also cause ramp lesions because of instability. Ramp lesions are difficult to diagnose and treat from the anterior compartment during arthroscopy. Typically, this repair requires technically demanding skills and is performed from the posterior portal using a suture hook under visualization with the arthroscope through the intercondylar notch. Inexperienced surgeons often struggle with using the posterior portal and the suture hook. Our all-inside repair technique using the FasT-Fix system (Smith & Nephew, Andover, MA) under direct visualization from the anterior compartment accompanied by a medial collateral ligament pie-crusting technique facilitates repair of ramp lesions without causing medial instability.

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.

Meniscal ramp lesions should be considered in anterior cruciate ligament-injured knees, especially with larger instability or longer delay before surgery

PURPOSE

To determine the incidence of meniscal ramp lesions in an anterior cruciate ligament (ACL) injured knees and to clarify whether ramp lesions are related to chronic ACL deficiency and increased knee instability.

METHODS

Consecutive ACL injured patients were evaluated arthroscopically for a ramp lesion via a trans-notch view and evidence of menisco-capsular injury was recorded. Other concomitant injuries to the knee were also noted. Incidence of meniscal ramp lesions, delay before surgery, and anterior-posterior stability was analyzed. All patients underwent bilateral KT-2000 evaluation.

RESULTS

One hundred and three consecutive ACL injured patients with a mean age of 24 years were included in this study. In total, a ramp lesion was found in 10 knees (9.7%) via a trans-notch view. None of these lesions could be identified by the standard view from the anterolateral portal. Other medial meniscal lesions were found in 26 knees (25.2%) by standard arthroscopic viewing. The ramp lesion group had significantly longer delay before surgery with a median of 191 days (p < 0.01) as well as a larger side-to-side difference of KT-2000 measurement (7.3 ± 1.8 mm; p < 0.01), compared with the intact medial meniscus group (53 days and 5.5 ± 1.5 mm, respectively).

CONCLUSION

Ramp lesions that were identified using a trans-notch view were not visualized with standard arthroscopic views. Increased anterior tibial translation and longer delay before surgery were seen in knees with ramp lesions. Careful inspection of the posteromedial menisco-capsular region is required as hidden menisco-capsular lesions may occur which may result in residual knee instability.

LEVEL OF EVIDENCE

Level II.

Editorial Commentary: Ramp Lesion: The Eye Sees Only What the Mind Is Prepared to Comprehend

If our consciousness is not prepared, it is difficult to identify a ramp lesion on preoperative magnetic resonance imaging due to its low sensitivity. In clinical practice, the prevalence of ramp lesion in the anterior cruciate ligament (ACL)-injured knee can be up to 30%, with an increased frequency in chronic ACL injuries and in revision ACL. To identify the ramp lesion, routine arthroscopic exploration of the posteromedial portion of knee using a trans-notch view during ACL reconstruction therefore seems essential. A decrease in reoperation rate for secondary meniscectomy from 25% to 7% since 2013 was published by our department, after the adoption of a systematic repair through a posteromedial portal with a suture hook device for ramp lesions identified at the time of ACL reconstruction.