MSK MRI

Five Histologic Layers of the Supraspinatus and Infraspinatus Tendons1. Layer 1: Superficial LayerThickness: ~1 mmComposed of fibers from the coracohumeral ligament.2. Dense Parallel Tendon FibersThickness: 3–5 mmDensely packed parallel collagen fibers.Stronger than layer 3 by twofold.Prone to intrasubstance tears between this layer and layer 3.3. Deep Layer with Non-Uniform Collagen Orientation..

https://youtu.be/pcUqlQzM1LY Summary: Footprint of the Subscapularis1. General Anatomy of the Subscapularis FootprintThe superior footprint of the subscapularis (SSC) tendon is broad and tapered inferiorly.A thin muscular insertion is located below the lesser tuberosity (LT) in the surgical neck of the humerus.The upper two-thirds are subjected to greater tension and mechanical stress.The lower ..

https://youtu.be/5GVpAklu8UE MRI Review: Identifying Subscapularis Tears✅ Understanding Rotator Cuff AnatomySubscapularis Tendon: Attaches to the lesser tuberosity, just anterior to the long head of the biceps tendon (LHB).Greater Tuberosity: Divided into three facets—superior, middle, and inferior. Supraspinatus has a smaller footprint than previously believed; much of this area is occupied by ..

https://youtu.be/Ilza4mNbkxgSubscapularis Muscle Anatomy and FunctionThe subscapularis is innervated by both the upper and lower subscapular nerves.Primary actions: internal rotation and adduction of the shoulder.Fatty Infiltration as an IndicatorFatty infiltration of the subscapularis muscle is a specific but insensitive marker for subscapularis tendon tears.The variability of this finding rela..

https://youtu.be/aUJeM0sB8aU✅ Indirect Imaging Findings of Subscapularis Tendon Tear1️⃣ Medial Displacement of Long Head Biceps TendonMedial dislocations or subluxations of the long head biceps brachii tendon are commonly associated with subscapularis tendon tears.Intraarticular dislocation of the long head biceps tendon suggests a full-thickness tear of the tendinous attachment to the lesser tu..

https://youtu.be/ZKoJzYiAHBwSubscapularis AnatomyOrigin and Structure: Multipennate muscle arising from the subscapular fossa, consisting of 4 to 6 tendon slips.Insertion: Primarily on the inferior facet of the lesser tuberosity, with variable attachment to the bicipital groove and greater tuberosity. The inferior third has a muscular attachment to the anterior humeral metaphysis via a thin memb..

https://youtu.be/Adfe07WqbFkATFL Avulsion FracturesThe most common type of ATFL injury is a pure ligamentous rupture, followed by an avulsion fracture from the tip of the lateral malleolus.Avulsion fractures from the talus are rare after lateral ankle sprains.Difficulty in Differentiating Os Subfibulare and Fibular Avulsion FracturesOs subfibulare and ATFL fibular avulsion fractures, especially ..

https://youtu.be/3VF_piDgBqcUnderstanding Anterior Talofibular Ligament (ATFL) InjuriesThe Anterior Talofibular Ligament (ATFL) is one of the most commonly injured ligaments in the ankle. This post highlights the types of ATFL injuries and key imaging features for diagnosis.Types of ATFL InjuriesPure Ligamentous RuptureAvulsion Fracture at the Fibular AttachmentAvulsion Fracture at the Talar Att..

https://youtu.be/wiHOwkRSeS8✅ The calcaneofibular ligament (CFL) is the second most commonly injured ligament in lateral ankle sprains, following the anterior talofibular ligament (ATFL). Understanding its anatomy and imaging characteristics is critical for accurate diagnosis. Orientation: It follows a curved course, requiring evaluation in multiple imaging planes.Dimensions: Rounded in cross-se..

https://youtu.be/ZMlA5DH3Kz41. Lateral Ankle Sprains and ATFLLigament Involved: Anterior talofibular ligament (ATFL).Imaging Characteristics: Best seen on axial MRI at the level where the talus appears elongated.Associated Injury: Often occurs in lateral ankle sprains due to inversion injuries.2. High Ankle Sprains and AITFLLigament Involved: Anterior inferior tibiofibular ligament (AITFL).Imagi..