Posterior Horn Of The Medial Meniscus Research Articles

Posterior Cruciate Buckling Angle Variations Are Associated with Different Patterns of Medial Meniscus Tears in Anterior-Cruciate-Deficient Knees: Results of a Prospective Comparative Magnetic Imaging Resonance Study

Background: The diagnosis of anterior cruciate ligament (ACL) tear relies on clinical evaluation and magnetic resonance imaging (MRI). Direct and indirect signs of ACL tear have been described with MRI evaluation. Posterior cruciate ligament (PCL) buckling has been described as an indirect radiographic sign of an ACL tear. Purpose: The aim of the present study was to assess the variations in PCL buckling angles in patients with ACL tears and in patients with isolated lesions in the posterior horn of the medial meniscus. In addition, the influence of different patterns of medial meniscus tears in ACL-deficient knees was investigated. Finally, the influences of risk factors such as tibial slope, delay from injury to surgery, absence of medial meniscus tear, degree of Lachman and pivot shift testing were also assessed. Study design: This was a cohort study. Methods: A total of 154 patients (78 in the group with ACL tear and 76 in the control group) were assessed with MRI and lateral weight-bearing X-ray to assess PCL buckling angle and tibial slope by two independent observers. The presence of a medial meniscus bucket handle or ramp lesion of the medial meniscus was assessed and recorded at the time of surgery. Results: PCL buckling angle measurement was highly reliable, with an ICC of 0.866 and 0.894, respectively, in the study group and the control group for interobserver reliability. The intrarater reliability was found to be high in PCL buckling angle for the study group [ICC = 0.955] and the control group [ICC = 0.943]. The mean angle in patients with ACL tear was 110.7 ± 15.2° and 115.3 ± 16.2° (for the two examiners) and 111.4 ± 12° and 114 ± 14.5° (for the two examiners) in patients with an intact, healthy ACL. An association emerged between bucket handle tears of the medial meniscus (p = 0.010) and a decreased PCL buckling angle and between ramp lesions of the medial meniscus and increased PCL buckling angle both (p = 0.024). Conclusions: Good inter- and intraobserver reliability for the measurement of the PCL buckling angle was observed. Increased PCL buckling angle values were observed in patients with concomitant ACL and bucket handle tears of the medial meniscus, while decreased angle values were observed in those who had ACL tear and ramp lesion of the medial meniscus. No statistically significant difference in the PCL buckling angle emerged between patients with ACL tears and those who had a healthy, intact ACL.

In the Acute Phase of Anterior Cruciate Ligament Rupture: Quantitative Assessment of Matrix Changes and Correlation between Different States of Meniscus and Adjacent Cartilage.

Cartilage and meniscus are important structures that maintain the health of the knee joint. Early detection of changes in the internal components of cartilage and meniscus before morphological changes occur is essential to prevent and delay the development of osteoarthritis (OA). This study was designed to determine the changes in the matrix composition of morphologically intact cartilage and meniscus during the acute phase of an anterior cruciate ligament (ACL) rupture, as well as the effect of different states of meniscus (intact or tear) on adjacent cartilage during the acute phase. This cross-sectional study compared and analyzed 50 patients in the acute phase of ACL rupture who underwent surgical treatment and 66 age-, weight- and height-matched healthy volunteers from May 2022 to May 2023 at our institution. Mean T2 relaxation times and effect sizes in different regions of tibiofemoral articular cartilage and meniscus were compared between the two groups using the Mann-Whitney nonparametric t-test, and correlations between different meniscal states and adjacent cartilage were analyzed. Both in the lateral and medial compartments of the knee, T2 relaxation times were significantly higher in all subregions of cartilage and meniscus in the ACL rupture group (p < 0.05), and the site of injury was predominantly centered in the medial compartment (femur, p = 0.000; tibia, p = 0.000; anterior horn, p = 0.000). In the respective compartments, the posterior horn of the lateral meniscus showed a significant positive correlation with the mid-cartilage of the femoral and tibial (r = 0.566, p = 0.035; r = 0.611, p = 0.02); and the posterior horn of the medial meniscus showed a significant positive correlation with the posterior tibial cartilage (r = 0.668, p = 0.018). During the acute phase of ACL rupture, the internal composition of the cartilage and meniscus undergoes significant changes, even if the morphology is intact. More importantly, the state of the meniscus significantly affects the internal composition of the adjacent cartilage. This is an early warning sign of OA, which should be closely monitored and carefully managed in clinical practice.

Degenerative medial and lateral menisci root tears: demographics, clinical presentation, imaging features, and associated findings.

(I) Characterize the demographics and clinical features of patients with meniscal root tears (MRT); (II) analyze the morphology, extent, and grade of MRT on MRI; (III) evaluate associated abnormalities on imaging; and (IV) evaluate the associations between imaging findings, demographics, clinical features, and joint structural abnormalities. A search was performed to identify meniscal root tears. Age, sex, BMI, and pain were recorded. Knee radiographs and MRI were reviewed. Presence, grade and morphology of MRT, meniscal extrusion, insufficiency fractures, as well as joint structural abnormalities were scored. For goals (I), (II), and (III), tabulations for categorical variables and mean for continuous variables were computed. MRT findings variables were described using percentages. For goal (IV), adjusted linear and logistic regression were employed. Ninety-six patients with a mean age of 56.6years (69 females) and mean BMI of 28.9kg/m2 were included; 88 of the MRT were located at the posterior horn of the medial meniscus (PHMM), and 82% were radial tear. The mean tear diameter was 3.8mm, and 78/96 tears presented with meniscal extrusion. Nineteen patients presented with subchondral insufficiency fracture (SIF), which was significantly associated with the gap of the tear (p = 0.001) and grade of the meniscal root lesion (p = 0.005). MRT typically found in middle-aged to older overweight and obese women. Lesions were mostly radial tears and located at PHMM and were frequently associated with meniscal extrusion and SIF. Moreover, the presence of SIF was significantly associated with the gap width and grade of root tear.

All the menisco-ligamentary structures of the medial plane play a significant role in controlling anterior tibial translation and tibial rotation of the knee. Cadaveric study of 29 knees with the Dyneelax® laximeter.

This study aimed to determine the respective roles of the anterior cruciate ligament (ACL) and the different components of the medial plane in the control of anterior tibial translation and internal and external tibial rotation. Twenty-ninefresh lower limbs, disarticulated at the hip, were tested in the anatomy laboratory. The following structures were isolated: the ACL, the anteromedial retinaculum (AMR), the medial collateral ligament (superficial and deep MCL), the posterior medial capsule (PMC) and the posterior horn of the medial meniscus (PHMM). The lower limb was positioned at 30° of flexion on the Dyneelax® laximeter (0.1 mm and 0.1° accuracies) and underwent anterior loads up to 200 N and internal and external tibial rotations sectioned from front to back. and the knee was then retested. The results were presented as relative gains in translation and rotations for each structure. Student's t test and Wilcoxon tests were used. The relative gains in translation for the ACL, AMR, superficial MCL, deep MCL, PMC and PHMM, respectively, were42.9%, 6.7%, 7.4%, 6%, 7.5% and 11.6%. The relative gains in internal rotation for ACL, AMR, superficial MCL, deep MCL, PMC and PHMM, respectively, were13%, 6.9%, 4.6%, 3.9%, 13% and 8%. The relative gains in external rotation for ACL, AMR, superficial MCL, deep MCL, PMC and medial meniscus, respectively, were8.9%, 6%, 9.7%, 13.8%,11.2% and 8.5%. All the relative gains in translation, internal and external rotations were significant at each step of transection (p < 0.01). The ligamentous structures of the medial plane constitute a functional unit in which each component has a specific passive contribution. This study highlights the importance of recognising the extent of the medial ligament tears and performing a medial side anatomic and individual reconstruction and a suture of a ramp lesion, in addition to an ACL surgery.

Posteromedial Corner Injuries of the Knee: Imaging Findings.

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

Meniscus update

Meniscus tears are classified as horizontal, longitudinal, radial, and complex tears. Flap tears are aspecific form in which aportion of the meniscus is displaced from ahorizontal or longitudinal tear. The question of whether it is possible to preserve the meniscus by meniscus repair is of crucial therapeutic importance. It is therefore important to specify not only the configuration of the tear but also its extent and location as precisely as possible. Cooper's zonal classification should also be used for this purpose. Lesions of the meniscus roots are of high clinical relevance. On the posterior horn of the medial meniscus, root lesions are usually degenerative; on the posterior horn of the lateral meniscus, they are often traumatic. It is important to familiarize oneself with the normal appearance and anatomical location of the meniscal roots. Ramp lesions have received particular attention in recent years, especially in patients with anterior cruciate ligament tears. Therefore, particularly the integrity of the attachment of the posterior horn of the medial meniscus to the tibial plateau must be analyzed. If the meniscotibial ligament tears along its course or at the insertion to the meniscus or if it avulses with ameniscus fragment, this is aramp lesion.

Comparison of needle and conventional arthroscopy for visualisation of predefined anatomical structures of the knee joint: a feasibility study in human cadavers and patients

BackgroundIn terms of the optics used for Knee arthroscopy, a large number of different endoscopes are currently available. However, the use of the 30° optics in knee arthroscopy has been established as the standard procedure for many years. As early as the 1990s, needle arthroscopy was occasionally used as a diagnostic tool. In addition to the development of conventional optics technology in terms of camera and resolution, needle arthroscopes are now available with chip-on-tip image sensor technology. To date, no study has compared the performance of this kind of needle arthroscopy versus standard arthroscopy in the clinical setting in terms of the visibility of anatomical landmarks.In this monocentric prospective feasibility study, our aim was to evaluate predefined anatomical landmarks of the knee joint using needle arthroscopy (0° optics) and conventional knee arthroscopy (30° optics) and compare their performance during knee surgery.MethodsExaminations were performed on eight cadavers and seven patients who required elective knee arthroscopy. Two surgeons independently performed the examinations on these 15 knee joints, so that we were able to compare a total of 30 examinations. The focus was on the anatomical landmarks that could be visualized during a conventional diagnostic knee arthroscopy procedure. The quality of visibility was evaluated using a questionnaire.ResultsIn summary, the average visibility for all the anatomic landmarks was rated 4.98/ 5 for the arthroscopy using 30° optics. For needle arthroscopy, an average score of 4.89/ 5 was obtained. Comparatively, the needle arthroscope showed slightly limited visibility of the retropatellar gliding surface in eight (4.5/ 5 vs. 5/ 5), medial rim of the patella in four (4.85/ 5 vs. 5/ 5), and suprapatellar recess in four (4.83/ 5 vs. 5/ 5) cases. Needle arthroscopy was slightly better at visualizing the posterior horn of the medial meniscus in four knee joints (4.9/ 5 vs. 4.85/ 5).ConclusionNeedle arthroscopy is a promising technology with advantages in terms of minimally invasive access and good visibility of anatomical landmarks. However, it also highlights some limitations, particularly in cases with challenging anatomy or the need for a wide field of view.

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.

Meniscal and Chondral Injury Patterns in Athletes With Anterior Cruciate Ligament Tear.

Anterior cruciate ligament (ACL) tears are a prevalent and debilitating injury among athletes, often accompanied by concurrent meniscal and chondral injuries. This study aimed to presenta comprehensive investigation into the patterns and prevalence of meniscal and chondral injuries in athletes with ACL tears. This is a cross-sectional study conducted on 600 athletic patients with ACL tears planned for reconstruction in a duration of five years. A combination of advanced imaging techniques, arthroscopic evaluations, and clinical data was used to provide a comprehensive understanding of the injury profiles of the participant athletes. Those findings were duly recorded and analyzed accordingly. Out of 600 patients, 67% (402)had at least one meniscal or chondral injury while the rest 33% (198) had isolated ACL injuries only. Of the patients,18% (108) were those who had both meniscal and chondral injuries present. Amongst the 57% (342) of patients who had meniscal injuries, injuries to the medial meniscus, lateral meniscus, and both the meniscus were present in 51% (175), 32% (109), and 17% (58) of patients, respectively. Amongst all associated meniscal injuries (n1= 404), around 52% (210) tears were present in the body of the meniscus, 31% (125) in the posterior horn, and 17% (69) in the anterior horn. Overall, it was noted that 22.77% (92) of meniscal tears were bucket handle tears of the medial meniscus,16.08% (65) were complex tears of the posterior horn of the lateral meniscus, and 9.60% (39) were complex tears of the posterior horn of the medial meniscus. Amongst 600 patients, 28% (168) of patients had at least one chondral injury present in association with ACL tear. Further, amongst thetotal number of chondral lesions reported (n2=297) in ACL-deficient knees, around 55% (163) of lesions were located on medial femoral condyle, 10% (30) were located on undersurface of patella, 10% (30) were global changes, 7% (20) were on lateral femoral condyle, and 5% (15) were located onmedial articulating surface of knee. A total of 61% (181) of chondral lesions were grade II, 21% (62) were grade III, 10%(30) were grade IV, and the least noted were 8% (24) grade I chondral lesions. The study concludes that medial meniscus injury was the most common meniscal injury in ACL-deficient knees and the bucket handle tear of the medial meniscus was the most common type of meniscal tearfollowed by the complex tear of the posterior horn of the medial meniscus. Further, the study also concludes that the medial femoral condyle is the most common site of chondral lesions in ACL-deficient knees.

The Principles of Knee Joint Preservation

The 3 primary factors involved with preservation of the knee joint include joint alignment, meniscal status, and ligament stability (in particular that of the anterior cruciate ligament [ACL]). These factors are interdependent and result in knee joint homeostasis when all factors are stable. When a deficiency exists in one of the factors, it will affect the others. For example, the ACL and posterior horn of the medial meniscus both act as restraints to anterior tibial translation. Thus, medial meniscal deficiency increases the risk for failure of ACL reconstruction, and chronic ACL insufficiency increases the risk for medial meniscus tears. Furthermore, all 3 of the factors of joint preservation have an impact on the articular cartilage status of the knee joint. Studies have shown that cartilage-preservation procedures do not result in optimal outcomes if there is joint malalignment, meniscal deficiency, or ligament deficiency. When evaluating patients with knee cartilage pathology, surgeons should be aware of the various factors involved in knee joint preservation and, if surgery is indicated, all factors should be addressed in order to support a successful result.

Arthroscopic All-Suture Anchor Technique for Unstable Ramp Lesions with Medial Meniscal Defects

A ramp lesion is a specific type of tear in the meniscocapsular junction of the posterior horn of the medial meniscus, usually associated with anterior cruciate ligament (ACL) injury. Biomechanical cadaveric studies have shown that ACL injury combined with ramp lesions significantly increases anterior tibial translation and external rotation, which ACL reconstruction alone cannot completely control. Additionally, ramp lesions are sometimes associated with medial meniscal defects, especially in cases of chronic ACL deficiency after repetitive traumatic events, in which the anatomical repair of the meniscocapsular junction is infeasible. This report describes a new arthroscopic repair technique using an all-suture anchor through a posteromedial portal for unstable ramp lesions with medial meniscal defects.

Meniscal Ramp Repair: Double-Row Anatomic Repair in Acute Anterior Cruciate Ligament Tears

The surgical management of medial meniscus ramp lesions can be challenging. Currently, repairs are performed via a trans-notch view, combined with a single posteromedial working portal. This technique, however, does not allow for a direct and complete visualization of the structures being injured, making a precise appreciation of the injured structures, as well as an anatomical repair, difficult. To overcome this limitation, a 2-portal posteromedial approach has recently been described. It allows better visualization of the mediolateral extent of the tear and a precise identification of the injured structures. In this Technical Note, an anatomic repair technique using this approach is presented. It consists of a double-row of sutures to repair individually both the meniscotibial and meniscocapsular ligament, thus restoring the 2 main components of the posterior horn of the medial meniscus to their natural insertion site.

Ramp Tear among Patients Undergoing Arthroscopic Anterior Cruciate Ligament Reconstruction in a Tertiary Care Centre.

Ramp tear is a specific injury that affects the posterior horn of the medial meniscus and its meniscosynovial or meniscocapsular attachments. The actual prevalence of ramp lesion is unknown due to the high probability of misdiagnosis or underdiagnosis caused by the low sensitivity of imaging modalities and poor visualization during arthroscopy. This study aimed to find out the prevalence of ramp tear among patients undergoing arthroscopic anterior cruciate ligament reconstruction in a tertiary care centre. A descriptive cross-sectional study was conducted among patients undergoing arthroscopic anterior cruciate ligament reconstruction after getting ethical approval from the Institutional Review Committee. Data from 1 March 2019 to 31 December 2022 was collected between 1 May 2023 to 30 May 2023 from medical records. The study included all patients who underwent arthroscopic anterior cruciate ligament reconstruction. Patients with a previous history of medial meniscus injury or repair and undergoing revision anterior cruciate ligament reconstruction were excluded. Convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Out of 412 patients who underwent arthroscopic anterior cruciate ligament reconstruction, 53 (12.86%) (9.63-16.09, 95% Confidence Interval) had ramp tears. The mean age of patients with ramp tears was 28.64±7.57 years. Among 53 patients, 42 (79.24%) were male and 11 (20.75%) were female. The prevalence of ramp tears in patients undergoing arthroscopic anterior cruciate ligament reconstruction in a tertiary care centre was found to be lower than other studies done in other international studies. anterior cruciate ligament injuries; anterior cruciate ligament reconstruction; arthroscopy.

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.

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. 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. Cohort study; Level of evidence, 3. 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. 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. 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.

Poster 140: The Effect of Posterior Tibial Slope and Flexion Angle on Posterior Medial Meniscal Root Forces

Objectives: Although the biomechanical and clinical consequences of posterior medial meniscal root (PMMR) tears have been previously reported, these have not been fully evaluated in terms of overall bony morphology. It is well documented that higher flexion angles lead to higher postero-medial pressure, with many groups proposing that PMMR tears are caused by elevated compression and shear forces at the root when the loaded knee is at high flexion angles. Additionally, several authors have advocated that increasing tibial plateau slope (PTS) is an anatomical risk factor for PMMR tears, due to the higher posterior shear forces at the root insertion site. Thus, the purposes of this study are to evaluate the forces across the PMMR utilizing a novel three-dimensional forces sensor with varying posterior tibial slopes and flexion angles. We hypothesized that an increased flexion angle and/or posterior tibial slope will result in increased posterior shear forces acting on the PMMR. Methods: Ten fresh-frozen cadaveric knees (53.2 mean age, all male) were tested in all combinations of the three states of posterior tibial slope (5⁰, 10⁰, 15⁰) and the four states of varying flexion angles (0⁰, 30⁰, 60⁰, and 90⁰). A novel three-axis sensor that determines force measurements in three orthogonal directions was installed below the posterior tibial plateau, with the specimen being mounted to a load frame which applied a 500-N axial load. A 5-Nm internal rotational (IR) torque was then applied. After the IR torque, a 5-Nm external rotational torque was applied. The amount of compression-tension and shear forces acting on the PMMR were measured. Results: Increased tibial slope significantly decreased tension and significantly increased compression of the PMMR (5°→10°: p = 0.0368, 5°→15°: p &lt; 0.0001, 10°→15°: p &lt; 0.0001) when the joint was loaded in compression. Increased tibial slope significantly increased anterior shear of the PMMR (5°→10°: p &lt; 0.0001, 5°→15°: p &lt; 0.0001, 10°→15°: p &lt; 0.0001) when the joint was internally rotated. Increased tibial slope significantly decreased compression of the PMMR (5°→10°: p = 0.0188, 5°→15°: p &lt; 0.0001) when the joint was externally rotated. Increased flexion angle significantly increased medial shear forces of the PMMR (0°→30°: p = 0.0362, 0°→60°: p = 0.0005, 0°→90°: p &lt; 0.0001, 30°→90°: p = 0.0434) when the joint was loaded in compression. 90° of flexion significantly increased tension of the PMMR (0°→90°: p = 0.0438, 30°→90°: p &lt; 0.0001, 60°→90°: p = 0.0005) when the joint was internally rotated. 30° of flexion angle significantly increased compression of the PMMR (0°→30°: p = 0.0004, 30°→60°: p = 0.0118, 30°→90°: p &lt; 0.0001) when the joint was externally rotated. Conclusions: Increased PTS results in an increase in compression forces acting on the posterior horn of the medial meniscus when the knee joint is loaded. Increases in flexion angles displays an increase in medial shear forces seen at the PMMR under a load. This increase in force may place the PMMR at increased risk of stress and potential failure after repair. This study begins to provide clinicians with information to create safer protocols to decrease the forces experienced at the PMMR after injury or postoperatively.

Arthroscopic Meniscus Ramp Repair: The Shoelace Technique

Background: A “ramp lesion” is described as an injury involving the peripheral attachment of the posterior horn of the medial meniscus. Ramp lesions are associated with increased loads on anterior cruciate ligament and leads to rotatory instability of knee. During anterior cruciate ligament reconstruction, failure to identify and treat ramp lesion leads to increased forces on the reconstructed graft and residual instability which ultimately increases chances for graft failure. It is important to identify the ramp lesions by looking at the posterior compartment and repair ramp lesion. Ramp lesions are still a challenge to treat due to misdiagnosis and long learning curve of current techniques. In this technique, we are presenting margin convergence shoelace technique to repair a large ramp lesion. Indications: Isolated ramp lesions or ramp lesions associated with other ligamentous injuries. Technique Description: Through standard anteromedial and anterolateral portals, diagnostic arthroscopy is done. Using Gillquist maneuver, posteromedial compartment is visualized to look for ramp lesion. Probing is done with 18-gauge spinal needle from posteromedial aspect of knee to look for hidden lesions and extent of tear. We use 2 additional portals, low and high posteromedial portals for ramp repair. Visualizing from anterolateral portal entry is made in the posteromedial compartment; low posteromedial portal is created at the level of meniscus; 8-mm passport cannula is inserted and used as working portal; and then, high posteromedial portal is created and used as viewing portal. Visualizing through high posteromedial portal rasping of ramp lesion is done. Now with knee scorpion loaded with 2-0 fiber wire, bites are taken along posterior margin of meniscus and capsular portion of tear edges alternatively in shoelace manner from lateral to medial. Finally, compression and knot tying are done and secured with multiple half hitches. Results: Surgical repair of ramp lesions is associated with good healing, and it restores stability of knee. Follow-up of more than 2 years shows better functional outcome and reduced retear rates. Discussion/Conclusion: Currently, there are a lot of techniques described for ramp repair. We present arthroscopic ramp repair with dual posteromedial portals by shoelace technique, which is a safe, easy, and cost-effective method and gives excellent results and good healing especially in larger tears. Patient Consent Disclosure Statement: 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.

Poster 321: MENISCAL RAMP LESIONS IN ADOLESCENT PATIENTS UNDERGOING PRIMARY ACL RECONSTRUCTION

Objectives: Meniscal ramp lesions describe a specific injury to the meniscocapsular junction at the posterior horn of the medial meniscus. The lesions are strongly associated with anterior cruciate ligament (ACL) injuries and may affect the biomechanical stability of the knee if left untreated. Despite the increasing rates of ACL reconstructions performed in adolescents each year, the prevalence and risk factors for ramp lesions in this patient population is poorly understood. The purpose of this study was to determine the prevalence and risk factors for ramp lesions in children and adolescent patients undergoing primary ACL reconstruction. Methods: All patients ≤19 who underwent primary ACL reconstruction at a single institutional between 2019 and 2021 were included. All surgeries were performed by three fellowship trained orthopedic surgeons. Patients were considered to have a ramp lesion if one was identified arthroscopically at the time of ACL reconstruction. Basic demographic data, preoperative imaging, and other arthroscopic findings at the time of ACL reconstruction were reviewed. Results: 247 consecutive patients who underwent ACL reconstruction were reviewed. Patients were excluded if they had had prior ACL injury, prior knee surgery, fibular hemimelia, or incomplete documentation. A total of 230 patients met inclusion criteria. Average age at time of injury was 15.7 years (range 4.0-18.2 years). A ramp lesion was identified in 12% of patients. Posteromedial tibial bone bruise on preoperative MRI and medial femoral chondromalacia at time of ACL reconstruction were associated with the presence of a ramp lesion, Figure 1A (OR = 2.6, 95% CI [1.15, 5.93]). A striation pattern of medial femoral chondromalacia was highly specific for the presence of a ramp lesion, Figure 1B (OR = 424.3, 95% CI [50.99, 3531.3]). Sensitivity and specificity for detecting a ramp lesion was 68% and 76% with preoperative MRI and 68% and 99.5% with medial condyle striations, respectively. Conclusions: The prevalence of a ramp lesion in our cohort was 12%, mirroring historical reports in adult patients. Posteromedial bone bruising and medial femoral chondromalacia, especially in a striation pattern, should increase suspicion for the presence of a ramp lesion in patients undergoing ACL reconstruction.

Morphological study of the arterial supply to the menisci in pigs with special reference to creating meniscus injury model.

Some reports have used pigs to establish models of meniscus injury. However, accurate information on the origin, course, and access of the arteries supplying the menisci remains unclear. This information is important to avoid damaging vital arteries when creating the meniscus injury model. In this study, fetal and adult pigs were employed to investigate the arterial supply of the menisci in pigs using gross anatomical and histological methods. Macro-anatomically, the anterior horn, body, and posterior horn of the medial meniscus were found to be supplied by the medial superior genicular artery, medial inferior genicular artery, and posterior middle genicular artery. The anterior and posterior horns of the lateral meniscus were supplied by the cranial tibial recurrent artery and the middle genicular artery, respectively. Anastomosis was observed in some cases, but appeared to be infrequent and too thin to expect the anastomotic branches to provide adequate blood flow. The histological examination showed that the arteries entered the meniscus along the tie-fiber. The access process of the artery was the same irrespective of whether it was in fetal or mature pigs, the medial or lateral meniscus, or the anterior horn or body or posterior horn. The medial inferior genicular artery ran along the medial meniscus in the circumferential direction. Therefore, the clinical longitudinal incision should take into account the characteristics of the vessel course in order to protect the blood vessels from damage. Based on the results of this study, the protocol for creating a pig meniscus injury model should be reconsidered.

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.

Meniscal Ramp Lesions in Adolescent Patients Undergoing Primary Anterior Cruciate Ligament Reconstruction: Significance of Imaging and Arthroscopic Findings

Background: Meniscal ramp lesions are associated with anterior cruciate ligament (ACL) injuries and may affect knee stability when left untreated. The diagnostic accuracy of magnetic resonance imaging (MRI) to identify this meniscocapsular injury of the posterior horn of the medial meniscus remains poor, and the arthroscopic findings require vigilance. Purpose: To determine the concordance of arthroscopic and MRI findings to better identify the presence of a ramp lesion in children and adolescent patients undergoing primary ACL reconstruction. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients aged <19 years who underwent primary ACL reconstruction at a single institution between 2020 and 2021 were included. Two cohorts were developed by the presence of a ramp lesion arthroscopically. Basic patient descriptive data, preoperative imaging (radiologist assessment and independent reviewer assessment), and concomitant arthroscopic findings at the time of ACL reconstruction were recorded. Results: An overall 201 adolescents met criteria with a mean age of 15.7 years (range, 6.9-18.2) at the time of injury. A ramp lesion was identified in 14% of patients (28 children). No differences were detected between cohorts with regard to age, sex, body mass index, weeks from injury to MRI, or weeks from injury to surgery (P > .15). The primary predictor of an intraoperative ramp lesion was the presence of medial femoral condylar striations, with an adjusted odds ratio of 722.2 (95% CI, 59.5-8768.2; P < .001); the presence of a ramp lesion on MRI had an adjusted odds ratio of 11.1 (95% CI, 2.2-54.8; P = .003). Patients with neither a ramp lesion on MRI nor medial femoral condylar striations had a 2% rate (2/131) of ramp lesion; those with either of the significant risk factors had a 24% rate (14/54). All patients with both risk factors (100%; n = 12) had a ramp lesion noted on intraoperative examination. Conclusion: The concordance of medial femoral condylar chondromalacia, particularly striations, noted during arthroscopy and posteromedial tibial marrow edema on MRI with or without direct evidence of posterior meniscocapsular pathology should increase suspicion for the presence of a ramp lesion in adolescents undergoing ACL reconstruction.