✅ Knee MRI Mastery/Chap 2.ACL and PCL99 (Fig 2-B.27) Scar tissue Attachment to the PCL https://youtu.be/cQ1YiSFDZ2I https://youtu.be/8yHOp_whDZU ✅ ACL Scarring: The scar tissue from the ACL most frequently attaches to the lateral side of the proximal PCL and the intercondylar notch. It is less common for the scar to attach back to the ACL's original attachment point. Among these patterns, scarring that reconnects the ACL to its original attachment point is rare but results in the .. 2024. 2. 25. (Fig 2-B.26) Scar tissue Attachment to the Anatomical origin of the ACL https://youtu.be/_dsyOjpKQ70 https://youtu.be/8yHOp_whDZU ★ Patterns of ACL Scarring: End-to-End Scarring: The torn ends of the ACL heal by connecting each other. Scarring to the PCL: The ACL forms scar tissue that attaches to the posterior cruciate ligament (PCL). Scarring to the Roof of the Intercondylar Notch: The ACL scar tissue attaches to the upper area of the intercondylar notch Scarring .. 2024. 2. 25. (Fig 2-B.25) Chronic ACL tears (non-visualization) https://youtu.be/0bFMpdbDbT0 https://youtu.be/8yHOp_whDZU ★ Chronic ACL tears Laxity and abnormal horizontal orientation of fibers are the most useful features for detecting ACL disruption in the chronic setting as opposed to fiber discontinuity and bone contusions, which are the most useful features in the acute setting. Nonvisualization of the ACL has also been described as a finding of chroni.. 2024. 2. 25. (Fig 2-B.24) Chronic ACL tear https://youtu.be/tBMO-n-5DZE https://youtu.be/8yHOp_whDZU ✅ Chronic ACL tears Laxity and abnormal horizontal orientation of fibers are the most useful features for detecting ACL disruption in the chronic setting as opposed to fiber discontinuity and bone contusions, which are the most useful features in the acute setting. Chronically torn ACL is often seen with the horizontal axis or may display.. 2024. 2. 25. (Fig 2-B.23) Subacute ACL tear https://youtu.be/hRrgWgyjkkk https://youtu.be/8yHOp_whDZU ✔️Subacute ACL tears typically have the following characteristics: Improved visibility of the torn ligament fibers as the initial bleeding subsides. The distal part of the ACL may become more horizontal. Clearer definition of fluid within the rupture site. Persistent bone bruising with a possible reduction in signal intensity or extent. P.. 2024. 2. 25. (Fig 2-B.22) Posterolateral bundle tear (Gap sign) -2 https://youtu.be/Mwug3dW_6so https://youtu.be/8yHOp_whDZU ✅Imaging Signs of Isolated Posterolateral Bundle Tear of the ACL An ACL tear may only involve one bundle. The specific imaging signs of an isolated posterolateral bundle tear include: 1️⃣Gap Sign Description: Presence of fluid signal and/or a gap. Location: Between the medial aspect of the lateral femoral condyle and the lateral aspect of.. 2024. 2. 24. (Fig 2-B.21) Posterolateral bundle tear (Gap sign) -1 https://youtu.be/KyybCz-ryFw https://youtu.be/8yHOp_whDZU ✅Imaging Signs of Isolated Posterolateral Bundle Tear of the ACL An ACL tear may only involve one bundle. The specific imaging signs of an isolated posterolateral bundle tear include: 1️⃣Gap Sign Description: Presence of fluid signal and/or a gap. Location: Between the medial aspect of the lateral femoral condyle and the lateral aspect of.. 2024. 2. 24. (Fig 2-B.20) Common pattern of the ACL Partial Tear https://youtu.be/uusDC9pFfiw https://youtu.be/8yHOp_whDZU 1️⃣Partial ACL tears The ACL consists of two primary bundles: the anteromedial bundle (AMB) and the posterolateral bundle (PLB). These bundles have different susceptibilities to injury based on the position and movement of the knee at the time of injury. Anteromedial Bundle (AMB) Injuries: The AMB is more prone to injury when the knee is .. 2024. 2. 24. (Fig 2-B.19) Low-grade Partial tears of the ACL https://youtu.be/4xDpKuZkMSI https://youtu.be/8yHOp_whDZU ✅Understanding ACL Partial Tears 1. Partial ACL Tears: Partial ACL tears account for 15% of all ACL injuries, presenting a diagnostic challenge. MR imaging accuracy rates for detecting partial tears range from 25% to 53%. The difficulty is distinguishing between partial and complete tears and accurately defining bundle involvement. 2. Ris.. 2024. 2. 23. (Fig 2-B.18) Meyers and McKeever classification system type IV https://youtu.be/uJBTc4Fl7ys https://youtu.be/8yHOp_whDZU ✅Intercondylar tibial eminence fracture. Intercondylar tibial eminence fractures stand out as a prevalent type of knee injury among children, most commonly observed between the ages of 8 and 14. These fractures exhibit a range of presentations, from nondisplaced to displaced and from comminuted to non-comminuted forms. Adults, in particul.. 2024. 2. 23. (Fig 2-B.17) Meyers and McKeever classification system type IV https://youtu.be/ydXMr6N0e98 https://youtu.be/8yHOp_whDZU ✅ Meyers and McKeever system (with modifications by Zaricznyj) Type 1: Minimally/Nondisplaced Fragment Type 2: Anterior Elevation Of The Fragment Type 3: Complete Separation Of The Fragment Type 3a: Involves A Small Portion Of Eminence Type 3b: Involves The Majority Of The Eminence Type 4: Comminuted Avulsion Or Rotation Of The Fracture F.. 2024. 2. 23. (Fig 2-B.16) Meyers and McKeever classification system type II https://youtu.be/y2ZFjGX6lG4 https://youtu.be/8yHOp_whDZU ✅ Meyers and McKeever Classification System for Tibial Spine Fractures Type I Injury: Characterized by a minimally displaced fragment. This type of injury typically responds well to conservative treatment methods. Type II Injury: This subtype features an anterior elevation of the fracture fragment, indicating a more significant displaceme.. 2024. 2. 22. (Fig 2-B.15) ACL Avulsion fracture from the femoral attachment https://youtu.be/UtQiRu-VtT8 https://youtu.be/8yHOp_whDZU ✅ ACL Injuries: Tear and Avulsion Fractures Overview Although most ACL tears involve the midsubstance of the ligament, avulsion of its tibial attachment occurs in a minority of cases and is more common in children than adults Osseous avulsions from the femoral condyle are unusual. It is important to distinguish ligamentous tears from avul.. 2024. 2. 21. (Fig 2-B.14) Type 2 ACL stump entrapment Lesion https://youtu.be/FBNWiXQyfPI https://youtu.be/8yHOp_whDZU ✅Stump Entrapment (SE) Lesions in ACL Injuries ✅ Stump entrapment (SE) lesions are critical considerations in the assessment of anterior cruciate ligament (ACL) injuries, presenting in two distinct types, each with unique morphological characteristics. 1️⃣ Type 1 SE Lesions: Characteristics and Formation Type 1 SE lesions typically mimic .. 2024. 2. 21. (Fig 2-B.13) Type 1 ACL stump entrapment Lesion https://youtu.be/gUkKTZcND08 https://youtu.be/8yHOp_whDZU ✅Understanding ACL Stump Entrapment: Diagnosis and Management ✅ ACL stump entrapment (SE) is a condition where a fragment of the torn anterior cruciate ligament (ACL) gets displaced into the intercondylar notch, potentially causing knee extension limitations or locking. This displacement can trigger inflammation and the accumulation of fi.. 2024. 2. 21. (Fig 2-B.12) Positive PCL angle and sign https://youtu.be/N-tf6Sa_Vdo https://youtu.be/8yHOp_whDZU ✅Secondary signs of ACL injury Buckling of the Patellar Tendon Buckling of the Posterior Cruciate Ligament (PCL) A Posterior PCL Line Uncovered Posterior Horn of the Lateral Meniscus Visibility of the Entire Posterior Cruciate Ligament or Lateral Collateral Ligament in One Coronal Image: Normally, these ligaments are not entirely visible .. 2024. 2. 21. (Fig 2-B.11) Secondary Signs of the Acute ACL Tears, Anterior Tibial Translocation https://youtu.be/17rWbgen564 https://youtu.be/8yHOp_whDZU ✅ Secondary Signs of ACL Injury Secondary signs are highly specific indicators of an Anterior Cruciate Ligament (ACL) injury, though they are less sensitive compared to primary signs. While primary signs are pivotal for assessing the ACL's integrity, secondary signs add limited extra diagnostic value. Here's a brief overview: 1️⃣ Anterior.. 2024. 2. 20. (Fig 2-B.10) Deep notch and Long notch signs https://youtu.be/cFT__qq9RZ8 https://youtu.be/8yHOp_whDZU ★ Osseous Injuries in ACL Tears with Pivot Shift Injury Osseous injuries typically affect the anterior/central aspect of the lateral femoral condyle and the posterior aspect of the lateral tibial plateau. Although less common, the posterior aspect of the medial tibial plateau and medial femoral condyle may also exhibit contusive injuries... 2024. 2. 20. (Fig 2-B.09) Mass-like tissue without normally oriented ACL fibers https://youtu.be/AI4fiajtjMo https://youtu.be/8yHOp_whDZU ✅ Stable vs. Unstable ACL Tears 1️⃣ Unstable ACL Tears: The following features are associated with unstable ACL tears (including unstable partial and complete tears): Nonvisualization of the ACL. Visualization of a single bundle. Masslike appearance of the ACL. Anterior tibial translation. Uncovering of the posterior horn of the lateral m.. 2024. 2. 20. (Fig 2-B.08) Abnormal orientation or bowing of the ACL https://youtu.be/aTPXinHnsFE https://youtu.be/8yHOp_whDZU 1️⃣ MRI Imaging Findings for ACL Tears: Positive Predictive Value: A discontinuous anterior cruciate ligament (ACL) or an abnormal horizontal orientation of the ACL is indicative of a 100% positive predictive value for an ACL tear. 2️⃣ Horizontal orientation of ACL: An angle greater than 15º between the roof of the intercondylar notch and.. 2024. 2. 20. (Fig 2-B.07) Proximal ACL tear https://youtu.be/HAe3KIplkU4 https://youtu.be/8yHOp_whDZU ✅ Normal ACL vs. ACL Tear at Femoral Insertion Normal ACL: Appears as an elliptical, homogeneous low signal on axial MRI images, indicating a firm attachment to the lateral femoral condyle. ACL Tear at Femoral Insertion: Axial MRI: Shows increased signal within the proximal ACL fibers or fluid between the torn ACL and lateral femoral cond.. 2024. 2. 20. 이전 1 2 3 4 5 다음
