sign in sign up
<<
Home , Subtalar joint

Cross-Sectional Anatomy

Upper Extremity Shoulder girdle • sternoclavicular between clavicle and clavicular notch of sternum • acromioclavicular joint between sternum and acromian process of scapula

MRI of the shoulder. Coronal T1-weighted view. MRI of the shoulder. Coronal T1-weighted view. 1, Trapezius muscle. 2, Acromion. 3, Infraspinatus tendon. 1, Trapezius muscle. 2, Acromioclavicular joint. 3, Acromion. 4, Deltoid muscle. 5, Humeral head. 6, Spine of the scapula. 4, Deltoid muscle. 5, Humeral head. 6, Supraspinatus 7, Infraspinatus muscle. 8, Teres minor muscle. 9, Tricipital muscle. 7, Spine of the scapula. 8, Infraspinatus muscle. 9, muscle. 10, Teres major muscle. Scapula. 10, Subscapularis muscle. 11, Teres major muscle.

MRI of the shoulder. Axial T1-weighted view. MRI of the shoulder. Axial T1-weighted view. 1, Pectoralis major muscle. 2, Deltoid muscle. 3, Coracoid 1, Pectoralis major muscle. 2, Biceps tendon (long head). 3, process. 4, Humeral head. 5, Glenoid. 6, Deltoid muscle. 7, Deltoid muscle (anterior). 4, Humeral head. 5, Glenoid. 6, Infraspinatus muscle. 8, Subscapularis muscle. 9, Teres minor muscle. 7, Deltoid muscle. 8, Infraspinatus Pectoralis minor muscle. muscle. 9, Subscapularis muscle. 10, Coracobrachialis muscle. 11, Pectoralis minor muscle.

Shoulder joint • Between the scapula and humerus • Supraglenoid and infraglenoid tubercle on glenoid fossa for attachment of biceps brachii and triceps brachii • Glenoid fossa Shoulder joint: labrum and

Glenoid labrum surrounds glenoid fossa and helps deepen articular surface of glenoid fossa

Elbow joint: Hinge and pivot joint between humerus, ulna and radius Radioulnar (neck of radius and ulnar tuberosity) and Radiohumeral (capitulum and radial head) pivot for supination and pronation Ulnohumeral joint (trochlea of humerus and coronoid process of ulna) is a hinge joint that allows for flexion and extension Elbow joint MRI of the elbow, T1, sagittal cut. MRI of the elbow, T1, sagittal cut. 1, Radial head. 2, Supinator muscle. 3, Anconeus 1, Olecranon. 2, Triceps muscle (lateral head). 3, muscle. 4, Capitellum. 5, Triceps muscle (lateral Humerus. 4, Biceps brachii muscle. 5, Brachialis head). 6, Extensor carpi radialis longus muscle. 7, muscle. 6, Ulnar artery and vein. 7, Pronator teres Biceps brachii muscle. 8, Cephalic vein. 9, muscle. Brachoradialis muscle.

Elbow joint ligaments

• Medial (ulnar) collateral and lateral (radial) collateral ligaments for joint stability • Annular encircles the radial head to prevent inferior displacement and allows the head of the radius to rotate freely

MRI of the elbow, T1, coronal cut. 1, Ulna. 2, Radial head. 3, Lateral epicondyle. 4, Extensor carpi radialis longus muscle. 5, Olecranon fossa. 6, Pronator teres muscle. 6a, Common flexor tendon. 7, Flexor digitorum superficialis muscle. 8, Supinator muscle. 9, Extensor digitorum muscle.

Wrist and hand

Distal radius and ulna, 8 carpals, 5 metacarpals, and 14 phalanges Wrist and hand joints and ligaments • Distal radio ulnar joint • Radiocarpal joint • Midcarpal joints • Carpometacarpal joints • 3 interphalangeal joints: metacarpophalangeal (MCP), proximal and distal interphalangeal (PIP and DIP) • Ulnar collateral, radial collateral and intrinsic ligaments reinforce the wrist joint Carpal tunnel

• Created by the concave arrangement of the carpal bones creating an enclosure for the flexor ligaments and median nerve • Guyon’s canal contains ulnar nerve and artery Cross-Sectional Anatomy

Lower Extremity joint Synovial ball and socket joint created by femur head and the acetabulum of the pelvis

MRI of the hip, coronal cut, T1. MRI of the hip, coronal cut, T1. 1, Gluteus medius m. 2, Gluteus minimus m. 3, Right 1, Greater trochanter. 2, Femoral neck. 3, Right femoral femoral head. 4, Urinary bladder. 5, Symphysis pubis. 6, head. 4, Obturator internus m. 5, Obturator externus m. 6, Femoral vessels. 7, Iliopsoas m. 8, Left femoral head. 9, Urinary bladder. 7, Acetabulum. 8, Gluteus minimus m. 9, Tensor fasciae latae m. 10, Iliac crest. Gluteus medius m.

MRI of the hip, coronal cut, T1. 1, Right sacroiliac joint. 2, Greater trochanter. 3, Lesser trochanter. 4, Obturator externus m. 5, Obturator internus m. 6, Gluteus muscle(s).

Hip joint labrum and ligaments

Hold femoral head inside the acetabulum

MRI of the hip, axial cut, T1. 1, Tensor fasciae latae m. 2, Iliopsoas m. 3, Urinary bladder. 4, Femoral vessels. 5, Sartorius m. 6, Rectus femoris m. 7, Gluteus medius m. 8, Left femoral head. 9, Obturator internus m. 10, Quadrilateral plate. 11, Posterior pillar. 12, Gluteus maximus m. 13, Greater trochanter.

MRI of the hip, axial cut, T1. 1, Tensor fasciae latae m. 2, Sartorius m. 3, Iliopsoas m. 4, Iliac vessels. 5, Urinary bladder. 6, Gluteus medius m. 7, Gluteus minimus m. 8, Gluteus maximus m.

MRI of the hip, axial cut, T1. Image 2 1, Tensor fasciae latae m. 2, Iliac vessels. 3, Small bowel. 4, Sartorius m. 5, Piriformis m.. 6, Rectum. 7, Gluteus minimus m.

Knee • joint formed by the femur, tibia and patella • 2 femorotibial and 1 patellofemoral articulation in a common Knee joint ligaments

External ligaments strengthen and support the knee: • medial and lateral collateral ligament provide lateral stabilization • patellar ligament is an extension of the quadriceps tendon and provides anterior support to the joint capsule Internal ligaments provide stability to the tibia and femur: • anterior cruciate helps prevent hyperextension and anterior displacement of the tibia • posterior cruciate helps prevent hyperflexion and posterior displacement of the tibia MRI of the knee: T2-weighted MRI of the knee: T2-weighted FATSAT, MRI of the knee: T2-weighted FATSAT, FATSAT, Sagittal. Sagittal. Sagittal . 1, Vastus medialis muscle. 2, Femur. 1, Vastus medialis muscle. 2, Quadriceps 1, Femur. 2, Quadriceps tendon. 3, Patella. 3, Medial , anterior horn. 4, tendon. 3, Patella. 4, . 5, 4, Patellar tendon. 5, Tibia. 6, Popliteal a. & Tibia. 5, Medial head gastrocnemius Anterior cruciate ligament. 6, Tibia. 7, v. muscle. 6, , Medial head gastrocnemius muscle. 8, posterior horn.7, Semitendinosus Posterior cruciate ligament. tendon. 8, Semimembranosus muscle.

Knee joint menisci

• Menisci located between the tibial plateaus and the femoral condyles • Provide cushioning MRI of the knee: coronal T1-weighted images. MRI of the knee: coronal T1-weighted images. 1, Vastus medialis muscle. 2, Vastus lateralis 1, Vastus medialis muscle. 2, Femur. 3, Vastus lateralis muscle. 3, Femur. 4, Medial meniscus. 5, muscle. 4, Posterior cruciate ligament. 5, Anterior cruciate . 6, Tibia. ligament. 6, Tibial collateral ligament. 7, Fibular collateral ligament. 8, Medial meniscus. 9, Lateral meniscus. 10, Tibia. 11, Fibula.

Ankle and Bones include: (talus, , navicular, cuboid, 3 cuneiform), 5 metatarsals and 14 phalanges.

MRI of the , sagittal cut, T1. 1, Tibia. 2, Tibialis anterior tendon. 3, Talus. 4, Navicular. 5, IntermediateArticulation cuneiform. between 6, 2nd metatarsal. talus 7,and Flexor digitorum brevis muscle. 8, Plantar aponeurosis. 9, Quadratus plantaecalcaneus muscle . is10, theCalcaneus. subtalar 11, Flexor joint hallucis longus tendon. 12, Flexor digitorum longus tendon.

MRI of the ankle, axial cut, T2FATSAT. 1, Navicular. 2, Medial cuneiform. 3, Intermediate cuneiform. 4, Lateral cuneiform. 5, Extensor digitorum longus tendon. 6, Cuboid. 7, Peroneus longus tendon. 8, Calcaneus. 9, Achilles tendon.

Subtalar and talocrural joints Ankle ligaments Provide support: deltoid, tibiotalar, tibiocalcaneal, tibionavicular, anterior & posterior talofibular, calcaneofibular, anterior and posterior tibiofibular

MRI of the ankle, Coronal cut, T2FATSAT. 1, Tibia (Medial malleolus). 2, Fibula (lateral malleolus). 3, Talus. 4, and peroneus longus tendons. 5, Calcaneus. 6, Abductor digiti minimi muscle. 7, Plantar aponeurosis. 8, Quadratus plantae muscle. 9, Abductor hallucis muscle. 10, Flexor hallucis longus tendon. 11, Tibiotalar ligament.

Blood supply Cross-Sectional Pathology

Upper extremity MR arthrography: shoulder joint

Postgadolinium T1 fat saturated magnetic resonance image of the right shoulder demonstrating contrast in the bursal space, confirming a full thickness tear of the supraspinatus tendon. Abbreviations: B=bursa, HH=humeral head, SS=supraspinatus tendon. Rotator cuff tear T2WI shows tear as area of high signal intensity T1

T2 FS Labral tear SLAP (Superior Labral tear Anterior and Posterior) to the biceps tendon Triceps tendon tear Most tears occur at the triceps insertion on olecrenon of ulna

Complete tear and muscle retraction

Both anterior and posterior components completely torn. Anterior component completely torn. Posterior component still intact Wrist: ganglion cyst Synovitis Inflammation of a . With TFCC tear

T1 IW Lower Extremity MR arthrography: Femoral acetabular impingement (FAI) syndrome • Occurs when there is a conflict between the proximal femur and the acetabular rim. FAI is a cause of premature osteoarthritis in the hip. • In cases of cam FAI, the nonspherical shape of the femoral head at the femoral head-neck junction and reduced depth of the femoral waist leads to abutment of the femoral headneck junction against the acetabular rim • In cases of pincer FAI, acetabular overcoverage limits the range of motion and leads to a conflict between the acetabulum and the femur

Pincer FAI with labral tearing CAM FAI with osseous protuberance Piriformis syndrome

• Patients usually present with lower extremity weakness and numbness • Characterized by enlargement of the muscle resulting in decreased space in the sciatic notch Hip dislocation Femur fracture MR arthrography: knee joints

Commonly used to evaluate for 1) recurrent meniscal tears after partial meniscectomy or meniscal repair, 2) evaluate the stability of chondral and osseous fragments. The presence of intra-articular contrast better demonstrates the size and depth of defects in the articular cartilage, 3) fragment instability, and 4) loose bodies.

diffuse cartilage loss (arrow) Recurrent tear with contrast normal cartilage (arrowhead) Loose bodies (arrowheads) tracking Meniscal tear

normal Anterior collateral ligament (ACL) • Most common ligamentus injury of the knee • Occurs from forced external rotation and abduction with hyperextension

Partial ACL tear normal CompleteComplete tear ACL tear Posterior collateral ligament (PCL) tear • Tears occur from a posterior force directed at a flexed knee or forced hyperextension • * Not as common as an ACL injury

normal Complete tear Patellar bursitis Tibial fracture Calcaneous fracture

Typical signs of a fracture: Irregularities in the cortical outline Displaced bone fragments Fracture line Chronic fracture

The displaced fragment becomes rounded off. Comminuted fracture

Where bone is splintered or shattered Bone cyst

Benign fluid filled cyst Muscle neoplasm Osteomyelitis

Infection of a bone or bone marrow Achilles Tear

partial complete Tendinosynovitis Inflammation of a tendon and fluid inside the tendonous sheath