At the Seashore 299 300 MRI of the Ankle: Trauma and Overuse Disclosure
William J. Weadock, M.D. of the
Presents
The 18 th atRadiology the Seashore
Friday, March 17, 2017
South Seas Island Resort Captiva Island, Florida
Educational Symposia TABLE OF CONTENTS
Friday, March 17, 2017
Ankle MRI: Trauma and Overuse (Corrie M. Yablon, M.D.)...... 299
Challenging Abdominal CT and MR Cases (William J. Weadock, M.D., FACR)...... 315
Knee MRI: A Pattern-Based Approach to Interpretation (Corrie M. Yablon, M.D.)...... 319
Complications of Aortic Endografts (William J. Weadock, M.D., FACR)...... 339
SAVE THE DATE - 19 th Annual Radiology at the Seashore 299 300 MRI of the Ankle: Trauma and Overuse Disclosure
Corrie M. Yablon, M.D. None Associate Professor
Learning Objectives Introduction • Identify key anatomy on ankle MRI focusing on ligaments • MR protocol of the ankle • Discuss common injury patterns seen on ankle MRI • Ankle anatomy on MRI • Explain causes of ankle impingement • Case-based tutorial of pathology • Describe sites of nerve compression
Protocol Planes Best to Evaluate… • Sag T1, STIR Axial Coronal • Ax T1, T2FS • Ankle tendons • Deltoid ligaments • Tibiofibular ligaments • Talar dome/ankle joint • Cor PDFS • Anterior, posterior talofibular • Plantar fascia • Optional coronal GRE for talar dome ligaments • Sinus tarsi cartilage • Sinus tarsi • Dedicated ankle chimney coil is best Sagittal – Quad knee coil or flex coil • Achilles • Plantar fascia • Sinus tarsi • Ankle joint
301 Axial Plane Axial Plane Achilles Lateral collateral ligaments involved Flexors, extensors, peroneals in 80-90% of ankle injuries: • Ant. Talofibular Anterior inferior tibiofibular ligament • Calcaneofibular Posterior inferior tibiofibular ligament • Post. Talofibular
Flexor retinaculum Superior extensor retinaculum Superior peroneal retinaculum Axial T1
Sagittal Plane Coronal Plane • Achilles • Deltoid ligament complex • Plantar Fascia seldom injured • Tibiotalar joint • Subtalar joints • Spring ligament • Sinus Tarsi – Contains talocalcaneal ligaments • Plantar fascia – Cervical lig – Inferior extensor retinaculum – Interosseous lig – Maintains hindfoot stability – Injury coexists with lateral collateral ligament sprains/ tears, inflammatory arthropathy or PTT tear • Sinus Tarsi Syndrome Lateral parasagittal T1 Coronal PDFS – Lateral ankle pain and hindfoot instability – See obliteration of the normal fat in the sinus
Coronal Plane Spring Ligament Tarsal Tunnel: Spring Ligament • Superior: Medial malleolus Complex • Lateral: Talus, calcaneus Originates at sustentaculum tali • Medial: Flexor retinaculum • Floor: Abductor Hallucis Muscle Attaches to navicular Contents: • PTT, FHL, FDL AH Runs deep to PTT • PT N,A,V Tarsal tunnel syndrome: • PT nerve compressed by: Plantar fascia: 3 cords Axial PDFS Coronal PDFS – Soft tissue mass, ganglion, nerve sheath tumor Toye et al AJR 2005
302 Spring Ligament Medial Ankle Anatomy • Functions to maintain arch • Deltoid ligament/ MCL • Degeneration associated with PTT – 6 components? dysfunction – Variably seen on dissection/ MRI • Failure leads to pes planus • Tibiospring ligament – Anterior
Image from Knee Surg Sports Traumatol Arthrosc (2010) 18:557–569
Lateral Ankle Anatomy Lateral Ligaments • Anterior tibiofibular ligament, • Anterior tibiofibular ligament, PTibFibL PTibFibL • LCL complex • LCL complex – ATFL, CFL, PTFL – ATFL, CFL, PTFL • Retinacula • Sinus tarsi ligaments – Superior & inferior peroneal – Talocalcaneal interosseous – Superior & inferior extensor – Cervical • Peroneal tendons – Brevis, longus
Image from Knee Surg Sports Traumatol Arthrosc (2010) 18:557–569 Image from Knee Surg Sports Traumatol Arthrosc (2010) 18:557–569
Hindfoot Lateral Ligaments • Bifurcate Ligament – Anterior process of calcaneus to navicular and cuboid – Inversion injury Lateral Ankle Pain – +/- avulsion of anterior process of calcaneus • Cervical ligament • Calcaneocuboid ligament
Image from Knee Surg Sports Traumatol Arthrosc (2010) 18:557-569
303 Chronic Lateral Ankle Pain
Diagnosis MR Grading System for Ligament Sprains • Anterior talofibular ligament tear I Mild sprain Soft tissue edema around ligament • Calcaneofibular ligament tear
• Talar dome contusion Thickening / edema of ligament with signal II Partial thickness tear • Osteochondral lesion abnormality • Inversion injury
III Complete tear Complete disruption or avulsion of ligament
Grade II Sprain of ATFL Lateral Ankle Pain After Inversion Injury • Ankle sprain • Peroneal tendon injury • Osteochondral injury of talar dome • Lateral talar process fracture • Sinus tarsi syndrome • Anterior impingement • Synovial cysts • Subtalar ankle instability Normal Sprain
304 Lateral Ankle Pain
Axial PD FS Coronal PD FS Sag STIR
Lateral Ankle Pain After Inversion Injury • Peroneal pathology associated with repeated inversion injuries/ severe ankle sprains • P brevis prone to splitting Medial Ankle Pain – Between fibula, p longus – P longus migrates into substance of p brevis • Chronic retromalleolar pain • Snapping
Medial Ankle Pain PTT Longitudinal Split Tear • PTT tears usually occur near medial malleolus • Loss of longitudinal arch when torn, causing flat foot • Middle aged/older women, RA • Increased incidence with accessory navicular bones • Also assoc. w/sinus tarsi syndrome, DJD of posterior subtalar joint
305 Chronic Medial Ankle Pain Os Naviculare Type II • If major portion of PTT inserts onto navicular, then foot may deviate into valgus • Abnormal signal, motion at synchondrosis >> djd • Pes planus • Spring ligament injury (arrowheads)
Chronic Pain - Patient 1 Patient 2
Patient 2 Calcaneonavicular Coalition • Tarsal coalitions common (6% population) • Calcaneonavicular (usually asymptomatic) and talocalcaneal (middle facet of subtalar joint) most common • Type I: Osseous, Type II: Cartilagenous, Type III: Fibrous, or combination • Associated with secondary DJD in posterior subtalar joint
306 Medial Ankle Pain Since Childhood Talocalcaneal Coalition • Occurs medially most often • Middle facet of talus most common facet • Coalitions usually present in childhood or teen years – May ossify in teen years • History of sprains, chronic pain, limited subtalar motion • May predispose to tarsal tunnel syndrome
Anterior Pain, Palpable Mass Anterior Tibial Tendon Tear • ATT has single blood supply from AT artery – Increased risk for ischemia, injury in older pts • Tears seen with increasing age, running on hills, diabetes, PVD • Can present as a mass
Runner With Heel Pain
Posterior Ankle Pain
307 Calcaneal Stress Fracture • Can be occult on radiograph • Can be associated with a large amount of edema in the surrounding muscle – Large degree of periosteal edema
Sudden Pain While Playing Tennis Achilles Rupture • Athletic activity 30-50 yrs • Concentric loading – Basketball, tennis, racquetball • RA, SLE, DM, gout • M:F 6:1 • Younger – tears at musculotendinous junction
Chronic Posterior Pain Achilles Tendinosis / Partial Tear • Middle, long distance running • Tennis, volleyball, track and field, soccer • Diabetics • Fluoroquinolones
308 Achilles Tendinosis Posterior Heel Pain • Occurs at: – Insertion at calcaneus – Watershed – 2-6 cm proximal to calcaneus • Decreased vascularity • Musculotendinous junction
Haglund Deformity Posterior heel pain when patient runs more than 15 minutes • Insertional Achilles tendinosis • Associated with bony posterosuperior calcaneal prominence – “Pump bump” – Impinges on Achilles tendon above the level of the distal insertion • Retro- Achilles bursitis • Retrocalcaneal bursitis • Thickened distal Achilles tendon – Can lead to fraying and tear
Normal Symptomatic Accessory Soleus and Achilles Tendonopathy • Inserts into achilles or calcaneus • Can present as mass on medial side of ankle • Exertional pain secondary to ischemia during exercise – localized compartment syndrome
309 Posterior Impingement Symptoms Chronic Lateral Hindfoot Pain
Sag T1 Sag STIR
Coronal T2FS Coronal T1FS post
Sinus Tarsi Syndrome Plantar Pain • Sinus Tarsi, lateral hindfoot pain, subtalar instability • Injury to contents of tarsal canal, sinus – Inversion injury – Decreased venous outflow >> fibrosis, nerve irritation • Effaced Sinus Tarsi fat • Synovitis, fibrosis, ligament disruption • Associated with PTT, spring ligament dysfunction
310 Plantar Fasciitis Ruptured Plantar Fascia • Lateral, central, medial components – Central cord most common • Low signal on all sequences • Should not exceed 4 mm in thickness • Runners, obese older women, seronegative spondylarthropathies (bilat) • MR: thickened fascia near attachment to calcaneus, increased T2 signal, surrounding edema, may see calcaneal edema
Radiographics 2000 Mar-Apr;20(2):333-52.
Posterior Ankle Pain Os Trigonum Syndrome • Posterior ankle impingement syndrome – Pain, disruption of cartilaginous synchondrosis between os trigonum and lateral tubercle of posterior talar process – Repetitive microtrauma • Os is compressed between FHL and PTFL on extreme dorsiflexion • Os compressed between calcaneus and tibia on extreme plantar flexion • Os trigonum hyperintense T2 • Hyperintense edema/synovitis posterior to talus, in posterior talus • FHL tenosynovitis
Nerves of the Ankle • Common entrapment neuropathies of the ankle • Sural nerve Nerve Compression Syndromes • Tibial nerve in tarsal tunnel – Divides into medial and lateral plantar nerves • Saphenous nerve • Deep peroneal nerve
311 Sural Nerve Posterior Sural Nerve: Ankle • Runs posterior in calf • Landmarks: Achilles tendon, lateral • Arises from branches of the tibial and common malleolus (lesser saphenous vein) peroneal nerves • Gives rise to lateral heel sensory – Medial cutaneous / tibial nerve nerves – Lateral cutaneous / common peroneal nerve – Lateral calcaneal nerve • Travels with small saphenous vein – Lateral dorsal cutaneous nerve • Crosses Achilles tendon 10 cm • Causes of injury proximal to calcaneus and runs – Trauma, fractures of lateral malleolus, to lateral heel calcaneus, cuboid, 5th metatarsal base, recurrent ankle sprains • Sensory to posterolateral leg – Surgery, laceration
Yablon et al. Radiographics. 2016 Mar-Apr;36(2):464-78. Yablon et al. Radiographics. 2016 Mar-Apr;36(2):464-78.
Tibial Nerve Tarsal Tunnel Syndrome • In tarsal tunnel distal to medial • Intrinsic compression malleolus – Osteophytes – Between FDL, FHL – Retinacular hypertrophy • Divides into medial and lateral – Tendinopathy plantar nerves – Tenosynovitis – Distal to medial malleolus – PNST • “Tarsal tunnel syndrome” – Ganglion cyst – Nerve compression • Extrinsic compression – Clinical diagnosis – Direct trauma – Presents with pain, numbness – Post surgical/traumatic fibrosis – Inflammatory arthropathy
Images: Anika et al, Orthopedics. 2013(36)2;81;154-157
Medial Plantar Nerve Lateral Plantar Nerve • Sensory: • Innervates: – Medial plantar foot and toes – Most of plantar muscles of foot, QP, FDMB, ADM, • Motor: lateral lumbricals – Dorsal and plantar interosseous muscles – FDB, AHL, FHB, medial lumbricals, Great toe and digital nerves • Travels with lateral plantar artery • Between FHB and QP • First branch = inferior calcaneal nerve (Baxter) • With medial plantar artery • Compression can cause lateral foot pain, numbness • Compression can cause medial foot/ arch pain
Illustration: Yablon et al. Radiographics. 2016 Mar-Apr;36(2):464-78. Illustration: Yablon et al. Radiographics. 2016 Mar-Apr;36(2):464-78.
312 Baxter Neuropathy Deep Peroneal Nerve • Inf calcaneal n./ Baxter • Travels with anterior tibial artery • Abductor digiti minimi – Baxter neuropathy • Landmark: anterior tibial artery: DPN follows into foot – Compression by with dorsalis pedis • AHL fascia • Courses under the inferior • AHL muscle hypertrophy extensor retinaculum • Foot pronation (runners) • Divides: • Calcaneal spur/ plantar fasciitis – Sensory: Medial branch • MRI: ADM muscle atrophy • With dorsalis pedis • 1st, 2nd toe interdigital space – Motor: Lateral branch Anterior • EHB, EDB Illustration: Yablon et al. Radiographics. 2016 Mar-Apr;36(2):464-78. Yablon et al. Radiographics. 2016 Mar-Apr;36(2):464-78.
Saphenous Nerve Take Home Points • Runs between medial malleolus and • Knowledge of detailed anatomy increases radiologist’s value to anterior tibialis tendon orthopedic surgeons • Lateral to saphenous vein – Ligaments, nerves • Sensation to medial arch • Mechanism of injury informs search for pathology • Injury: – Saphenous vein harvest, saphenous vein access, fem-pop bypass surgery, thrombectomy
Yablon et al. Radiographics. 2016 Mar-Apr;36(2):464-78.
313 314 315 316 Challenging Abdominal CT and MR Cases
William Weadock, MD, FACR
No syllabus materials
317 318 319 320 Knee MRI: A Pattern Based Disclosure Approach to Interpretation
Corrie M. Yablon, M.D. None Associate Professor
Overview Protocol • Protocol • 1.5 T or 3 T magnet • Anatomy • Knee coil: 8 channel • Cases – Menisci – Tendons – Ligaments
Protocol Knee Anatomy • Routine: No contrast • Compartments • Tendons/Muscles – Ax T2FS and T1, Sag PD, PDFS, Cor PDFS – Patellofemoral – Quadriceps – Calf – Lateral tibiofemoral • Vastus lateralis • Gastrocnemius – Covers most indications – pain, sports injury • Vastus • Soleus – Medial tibiofemoral – T1 axial helpful to assess incidental marrow findings intermedius • Popliteus – Proximal tibiofibular • Vastus femoris – Patellar Tendon • Knee arthrogram • Vastus medialis • Bones: – Post operative meniscus, intra-articular body – Hamstrings – Femur • IV contrast: • Semimembranosus – Tibia • Semitendinosus – Pre and post contrast sequences – Fibula • Biceps femoris – Infection, tumor long head – Patella • Gracilis
321 Knee Anatomy Sagittal Checklist • Ligaments • Neurovascular • Menisci – ACL, PCL – Femoral and popliteal arteries • ACL, PCL and veins – Posterolateral corner • Extensor mechanism – Posteromedial corner – Saphenous nerve – Patella, patellar and quadriceps tendons – Anterolateral corner – Sciatic nerve – Patellofemoral cartilage and marrow – Anteromedial corner • Tibial • Cartilage, marrow, • Common peroneal • Cartilage • Hoffa’s fat pad, suprapatellar fat pad • Other • Fibrocartilage (menisci) • Posterolateral and posteromedial – Popliteal (Baker) cyst • Hyaline (articular) cartilage corners – Bursae • Muscle
Coronal Checklist Axial Checklist • Medial, lateral menisci • Joint effusion • Medial, lateral compartment • Baker cyst cartilage, marrow • Patellofemoral cartilage and marrow • Collateral ligaments • Cruciate ligaments • Cruciate ligaments • Patellar retinacula • Posteromedial and posterolateral corners
Menisci Meniscal Anatomy Function: • Roots • Transmit axial and torsional forces • Fibers across the joint – Radial • Cushion mechanical loading – Circumferential • Increase surface area for femoral – Perforating condylar motion • Blood supply • Distribute synovial fluid • Geniculate arteries • Perimeniscal capillary plexus
322 Vertical Longitudinal Tear Radial Tear • Propagates through multiple slices in • May see blunting of anterior horn or free the meniscus; seen as vertical signal edge of meniscus abnormality on sagittal images • “Ghosting” of meniscus when scrolling • Predisposes to bucket handle tears through sagittal plane (displaced tears) • Causes extrusion of meniscus by disrupting circumferential hoop strength if it extends completely through
Horizontal Cleavage Tear Flap or Oblique Tear • Classically extends to apex or • Also known as “parrot beak” or free edge “oblique” • Propagates longitudinally • Horizontal tears can also extend to superior or inferior articular surface
Complex Tear Bucket Handle Tear Several types of tear • Displaced longitudinal tear of morphology concurrently the meniscus • Radial • Usually medial but can be lateral • Oblique • Double PCL sign • Vertical • Double delta sign • Horizontal • BHT’s involve 2/3 of meniscal circumference
323 Direct Signs of Meniscal Tear Indirect Signs of Meniscal Tear MRI criteria for calling a tear: • Double PCL sign 1. Abnormal signal extending to • Too large meniscus articular surface on 2 consecutive – “Double delta sign” of images; 3mm thick anterior horn lateral meniscus – Or two orthogonal images • Meniscal extrusion 2. Abnormal morphology of meniscus – 3mm or more – “divot”, “ghost”, too small, too big, • Subcondral marrow edema etc. underlying meniscal tear 3. Injury at the meniscocapsular • Parameniscal cyst junction
Illustrations from Stoller, 2nd ed
Radial Tear, Lateral Meniscus
Cases
Radial Tear, Lateral Meniscus • Junction of anterior horn and body lateral meniscus • Vertically oriented • Perpendicular to the free edge of the meniscus • Usually seen on only one slice
324 Bucket handle tear of the medial meniscus, double PCL sign • See displaced meniscal tissue on multiple sequential images in sagittal and coronal planes • Posterior horn of MM appears absent or deficient >> look for the displaced meniscal fragment • Intercondylar notch fragments
325 Posterior Horn Lateral Meniscal Tear with Parameniscal Cyst
Discoid Medial Meniscus
Lateral meniscal tear, anterior horn, meniscal cyst
Lateral bucket handle tear Lateral bucket handle tear
326 Lateral bucket handle tear • Occurs much less frequently than medial bucket handle tears • Double delta sign (two anterior horns) due to displaced meniscal fragment • Diminutive posterior horn
Horizontal Cleavage Tear • Posterior horn peripheral vertical tear at the meniscocapsular junction and ACL tear • Extrusion of anterior horn MM
Horizontal Cleavage Tear MM Tear, Parameniscal Cyst • Cysts usually occur at the periphery of the meniscus • Associated w horizontal cleavage tear pattern • Present at joint line • Lateral more common than medial • Can dissect through joint capsule and MCL • Signal: fluid – protein (high T2, interm-high low TE) • Treatment: resection, repair the tear
327 Anterior Cruciate Ligament • One of the 4 major ligamentous stabilizers of the knee • Runs lateral to medial, femoral intercondylar notch to tibial eminence Ligaments • Primary restraint to anterior tibial displacement: – Prevents hyperextension of the knee – Prevents internal rotation of the lateral tibia • ACL most commonly injured knee ligament – Composed of AM, PL bundles
ACL tear on MRI • Injury usually due to: • Direct Signs • Indirect Signs – Pivot shift – valgus load, external rotation and flexion of tibia • Disrupted ACL fibers – Joint effusion or hemarthrosis – Kissing contusions – Dashboard injury: direct blow to tibia with knee in flexion – Avulsion from femoral or tibial attachments +/- bone – Anterior translation of lateral – Hyperextension injury: direct force applied to anterior tibia with fragment tibia to distal femur planted foot – Mid-substance rupture – Segond fracture • ACL fibers too shallow – Lateral femoral condylar (concave) in relation to notch sign Blumensaat's line – PCL laxity – See the entire LCL on one coronal image
ACL tear Posterior Cruciate Ligament • Central stabilizer of the knee • Prevents: – Posterior displacement of the tibia on the femur – Excessive varus or valgus stress – Internal rotation of tibia on femur • When injured, usually multiligamentous injury • Isolated injury can occur, but rare
Normal ACL
328 PCL tear Pivot Shift: Kissing Contusions
Normal PCL
Pivot Shift Hyperextension • Foot planted, valgus stress w • Kissing contusions of anterior internal rotation femoral condyle and tibial • Look for: plateau – ACL disruption • Either ACL or PCL injury – Osteochondral impaction • Transient posterior dislocation injuries of lateral femoral • Look for: condyle, posterolateral tibial plateau – Injury to posterior vascular structures – Posterior capsular injury – Osteochondral impaction – MMT or LMT injuries of anterior femoral condyle, tibial plateau – Posterior capsular injury
Dashboard Clipping Injury • MVC, anterior tibia into • Football dashboard • Direct impact to lateral knee • Posterior subluxation of tibia • MCL tear with respect to femur • Multiligamentous injury • Look for: • Look for: – Anterior tibial impaction injury – LFC contusion – PCL rupture – MCL tear – Capsular injuries – Cruciate tear – Capsular injuries
329 Medial Collateral Ligament MCL tear • Medial stabilizer • Also called tibial collateral ligament • 8-11 cm long (superficial component) – Deep component: meniscotibial and meniscofemoral ligaments • Arises from medial epicondyle of femur; attaches to 5 cm below the tibial plateau and behind the pes anserine tendons • Injured by valgus force
Normal MCL Coronal PD FS
Lateral Collateral Ligamentous Complex • Iliotibial band • Fibular collateral ligament • Biceps femoris tendon • Popliteus • Helps prevent varus angulation of the knee
Normal LCL
Posterolateral Corner Anatomy Posterolateral Corner Anatomy
• Lateral collateral 1 1. Lateral collateral 1
ligament LFC ligament LFC 2 2 • Fabellofibular 2. Fabellofibular ligament ligament • Arcuate complex 3. Arcuate complex • Popliteofibular ligament 4. Popliteofibular ligament 3 3 • Popliteus tendon 5 5 4 5. Popliteus tendon 4 Fib Fib
Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press. Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press.
330 Posterolateral Corner Injury Posteromedial Corner Anatomy 1. Medial collateral ligament (deep and superficial) 2. Posterior oblique lig 3. Semimembranosus tendon 3 4. Medial head gastrocnemius 1 2 5. Medial meniscus PH 4 6. Oblique popliteal lig
Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press. Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press.
Posterior Capsular Anatomy Posteromedial Corner Injury 1. Biceps femoris tendon • Usually ACL and/or PCL injury 2. Fibular collateral ligament • Anteromedial rotatory instability (AMRI) 3. Arcuate ligament 5 • Injury may predisposed to early 4. Popliteus tendon ACL/ PCL graft failure if not 2 1 5. Semimembranosus tendon 6 recognized at injury 6. Oblique popliteal ligament 4
7. OPL arm of the SMMT 3
Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press. Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press.
Anterolateral Ligament Anatomy Anterolateral Ligament Injury • Proximal attachment • Proximal attachment posterior to LCL posterior to LCL • Distal attachment to • Distal attachment to anterolateral tibia anterolateral tibia • Avulsion of tibial • Avulsion of tibial 5 4 attachment = Segond attachment = Segond fracture fracture 1 • Pivot shift, associated with • Pivot shift, associated with 3 ACL injury 2 ACL injury • Attaches to lateral • Attaches to lateral meniscus meniscus via meniscotibial via meniscotibial and and meniscofemoral ligs meniscofemoral ligs
Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press. Images from Hansford, Yablon. Multiligamentous Injury of the Knee. SMR 2017. In press.
331 Extensor Mechanism • Quadriceps tendon • Patella • Patellar tendon Extensor Mechanism • Medial & lateralretinacula • Patellofemoral and patellotibial ligaments • Hoffa’s fat pad
Extensor Mechanism Transient Patellar Dislocation • Allows for flexion and extension of the knee • Knee flexed; internal rotation • Injuries include: • Usually lateral – Quadriceps tendinosis /tear • Patient may not be aware; – Patellar tendinosis /tear usually reduces in the field • Jumper’s knee • Look for: • Osgood Schlatter – Contusions lateral femoral trochlea, medical patellar • Prepatellar bursitis facet • Patellar dislocation (lateral typically) – MPFL, medial retinacular tear • Osteoarthritis of patellofemoral compartment – Avulsion fragments – Cartilage injury – MCL, other ligamentous injury
Medial Patellofemoral Ligament (MPFL) • Major patellar stabilizer • Surgeons need to know • MPFL reconstruction • Predisposing factors to patellar Cases dislocation: – Shallow trochlea – Patella alta – Patellofemoral tracking disorder
332 Multiligamentous Injury Football Player: Posterior Knee Dislocation
Football Player: Posterior Knee Dislocation Myxoid Degeneration ACL
Myxoid Degeneration of the ACL Paddleboarding Injury - Multiligamentous • Fusiform tendon thickening (“celery stalk” appearance) • Associated with degeneration or injury • May predispose to tear later
333 Paddleboarding Injury - Multiligamentous Normal ACL Reconstruction
ACL Reconstruction ACL Reconstruction Failure
Posterolateral Corner Injury Posterolateral Corner Injury
334 Posterolateral Corner Injury Posterolateral Corner Injury
Posterolateral Corner Injury Posterolateral Corner Injury
Posterolateral Corner Injury Iliotibial Band Syndrome • Sprain/strain of the supporting structures of the posterolateral corner of the knee • Fibular head avulsion fracture is diagnostic of the PLC injury • ACL, PCL tears • Arcuate ligament/lateral head of gastrocnemius • Popliteal tendon/muscle tear • LCL, fabellofibular ligament, popliteofibular ligament • Posterolateral joint capsule tear • Surgical repair of ruptured ligaments and tendons
335 Extensor Mechanism
Patellar Dislocation with Torn Medial Retinaculum • MR findings: edema/fx medial side of patella; lateral femoral trochlea – Torn medial patellar retinaculum and medial patellofemoral ligament – Joint effusion – Patellar cartilage defect • Associated with patella alta • Abnormal patellofemoral tracking – Patellar subluxation – Shallow trochlear sulcus • More common in women
Lateral Patellofemoral Friction Syndrome Quadriceps Tendon Rupture • Young females • PF mal-tracking • Impingement of Hoffa fat pad between LFC and PT • +/- patellar tendinosis • Anterolateral pain
336 Total knee prosthesis with ruptured quadriceps Torn Patellar Tendon
337 338 339 340 Aortic Endograft Complications Disclosure
William J. Weadock, MD Department of Radiology None University of Michigan
Introduction How Do They Work? • Indications • Friction fixated at ends • Devices • Anchored by scarring, metallic hooks • Followup • Thermal memory • Complications • Interesting cases
Devices Cook Zenith Endograft • Common devices – Cook Zenith – Gore Excluder – Medtronic AneuRx, Talent – Aorfix – Ancure – Uni-iliac • More out there …
341 Medtronic AneuRx
http://www.zenithstentgraft.com/physicians/US/aAAA/PDF/AAAMP605.pdf
AneuRx on MRA Medtronic Talent (+ Iliac-Renal Bypass)
Gore Excluder Aorfix
342 Ancure Ancure Withdrawn from Market 2002
Aorto-Uniiliac (Cook) Follow Up Imaging • Lifelong follow up • Usually by CT • MR – Requires plain film to check for metal fracture • Change in position • Change in aneurysm sac Plug • Check for leak
Aneurysm Sac - 8 Year Follow up Why all the Followup? • Cook Zenith device
• Shrinkage (≥5 mm) – 62% • No change – 20% • Increase (≥5 mm) - 18%
Mertens J et al. J Vascular Surgery 2011.
343 Aneurysm Sac Size - 2 Year Follow up Aneurysm Rupture After Stent Graft $ • Literature review of cases of rupture # • 270 cases found " • Limited by study design – literature cases !
• Cause – Endoleaks > migration
Melissano G et al. J Vascular Surgery 2005. Schlösser FJ et al. Eur J Vasc Endovasc Surg. 2009 Jan;37(1):15-22.
Aneurysm Rupture After Stent Graft Ruptures by Endoleak Type ! # ! # !
! # ! " # $! #
Schlösser FJ et al. Eur J Vasc Endovasc Surg. 2009 Jan;37(1):15-22. Schlösser FJ et al. Eur J Vasc Endovasc Surg. 2009 Jan;37(1):15-22.
Follow Up on CT Non contrast “CT Angiograms” • Non contrast • Poor renal function – High attenuation blood, calcium – Most common • Delayed • Severe allergy – 300 sec better than 60 sec – Use narrow windows, measurements • Young patients • May catch endoleaks
Iezzi R et al. Volume 32(4), July/August 2008, pp 609-615.
344 Non contrast “CT Angiograms” Follow Up CT Report • Maximum aneurysm sac diameter – 5 mm growth warrants evaluation • Combined volume of stent graft / sac – 5% growth warrants evaluation • Presence of leak
Maximum Intensity Projection (MIP) Volume Rendered
Maximum Diameter – Outer Walls Volumetric Evaluation – Noncontrast CT • Volume increase >2% should prompt further evaluation w/contrast enhanced CT • Decreased radiation • 3D tech can perform volumetric analysis in less than 20 minutes!
5.6 x 5.1 cm Bley TA et al. Radiology 2009; 253: 253-262
Volume Measurements Follow Up MRI Technique • MR safe patient • GRE • White blood techniques Aneurysm Sac • May be useful for some devices – Nitinol or Elgiloy
2% = 4 mL • Multiple phases may help define abnormalities
345 Follow Up MRI Problems Zenith Follow up on MRI (2007) • MR safe devices • Not recommended by Vendor (Cook) • High T1 signal of semi-acute blood • Stainless steel device • May not see device fracture • 550 patients with stent • Artifact depends on device composition • 22 had MRI – Stainless steel devices • 17 consented to record review • Significant susceptibility artifact • No change in structure, position or function of the graft
Hiramoto JS Et al. Journal of Vascular Surgery. Volume 45, Issue 3, March 2007, pp. 472-474
Zenith Follow up on MRI Cook Zenith on MRI • “We hesitate to state that the Zenith stent-graft is MRI safe, but we have concluded, on the basis of the findings of this study, that the benefits of MRI should not be denied to every patient with a Zenith stent graft.”
• UM – We now do MRIs on these patients
… but not to look at stent or the sac
Hiramoto JS Et al. Journal of Vascular Surgery. Volume 45, Issue 3, March 2007, pp. 472-474
Endoleak on MRI ? Follow Up Ultrasound Technique • Some do it – we sometimes do it • May see dynamic changes in sac • US Contrast helps …
… in other countries
Axial GRE Fat Sat Axial GRE Fat Sat Pre Contrast Post Contrast
346 Ultrasound - Zenith Ultrasound - Zenith
Endograft Complications • Infection • Migration • Leaks Stent Graft Leaks • Kinks • Thrombosis • Rupture
Type I Leaks Type I Fix • Thought to be rare outside angio suite • Secure fixation with overlapping extension • Incomplete seal at landing zone • Remove the graft • (Distal) – Occlude, fem-fem bypass
Proximal (1A) Distal (1B)
347 Type IA - Infolding Type IA - Leak
Type IA - Leak Type IA (Combined)
Distal Endograft Migration Endograft Migration • Leads to – Type 1A Endoleak – Kinking
348 Type II Leaks Type II Stent Graft Leak • Retrograde flow from collateral to sac • Incidence 10-20% • Common arteries – Lumbar – Inferior mesenteric – Median sacral – Accessory renal
Precontrast
Stavropoulosa SW and Baum RA. Volume 17, Issue 4, December 2004, Pages 279-283
Type II Leak – MRI and CT Type II Leaks • Related to type of device • Zenith lower incidence • Number of ingress / egress vessels important • Destruction of endoleak cavity most important
Axial GRE Fat Sat Post Gad Delayed CT with Contrast
Stavropoulosa SW and Baum RA. Volume 17, Issue 4, December 2004, Pages 279-283
Type II Leaks – To Fix or Not? Type II Fix • Some consider to be insignificant • Embolize feeder vessels – May thrombose – Doesn’t work well – Follow aneurysm sac size – Collaterals form … • May transmit arterial pressure to aneurysm sac • Direct puncture of sac – Translumbar
349 Type II Leak Type II Fix
Type III Leaks Type III Leak • Defect or failure of the graft material • Includes junctions between components
Stavropouosa SW and Baum RA. Volume 17, Issue 4, December 2004, Pages 279-283
Type 3 Leak Stent Graft Leak (Type III)
350 Type III Fix Type IV Leaks • Angioplasty • Leakage through fabric • Cover defect with stent graft extension • Less common with current devices • Embolize graft limb, fem-fem bypass
Stavropouosa SW and Baum RA. Volume 17, Issue 4, December 2004, Pages 279-283
Type IV Fix Type V - Endotension • No treatment needed • Enlargement of aneurysm sac without visible source • Fixes when anticoagulation removed • Transmits systolic pressures to sac • Follow volume of sac
Type V - Endotension Conclusions • Aortic stent grafts becoming more common • Imaging important before and after procedure • Knowledge of devices and complications essential
6.8 cm 7.6 cm 6 months later
351 Thank you!
Any Questions?
352 353 354 SAVE Educational Symposia THE DATE
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