None to report. Transverse tendon rupture Partial or complete Acute Focally increased signal Edema Hemorrhage

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1 None to report Kate O Mara, DO AOCR Annual Conference April 21, 2015 Review pertinent anatomy Discuss typical appearance of injured ligaments & tendons Consider commonly associated injuries Recognize injury patterns Normal tendon Low signal T1 & T2 Magic angle common Trace fluid surrounding Tendinosis Increased diameter Increased signal T2 Occasional thinning/attrition (PT & PB) Longitudinal split tears Discrete linear high T2 signal parallel to tendon fibers Transverse tendon rupture Partial or complete Acute Focally increased signal Edema Hemorrhage Chronic Scarring/fibrosis may bridge the gap Extent of involvement Important for treatment planning Length, percentage of cross sectional area involved 1

2 Posterior Achilles Plantaris Medial Tibialis Posterior Flexor Digitorum Longus Flexor Hallucis Longus Lateral Peroneus Brevis Peroneus Longus Anterior Tibialis Anterior Extensor Digitorum Longus Extensor Hallucis Longus Largest tendon in body, pathology common Gastrocnemius/soleus to midposterior calcaneal tuberosity Normal AP diameter 4-7mm, flat or concave (90%) No sheath Normal tendon has punctate & linear high signal distally (connective tissue & vessels) Kager s fat pad anterior Two distal bursae (normally <1mm AP) Retro-Achilles (superficial) Retro-calcaneal Action: plantar flexion of ankle, heel inversion (minor contribution) Most common location of injury is 2-6cm proximal to insertion (critical zone) Poor vascularity, slower repair Degeneration by 4 main mechanisms Hypoxic-fibromatosis Myxoid Lipoid Osseous-calcific 2

3 Most frequent type seen in tendon rupture Relative hypovascularity of critical zone Follows multiple symptomatic episodes Microtears not visible on imaging MRI Fusiform thickening Loss of normal concave anterior margin AJR 2013;200: JAAOS January 2009vol. 17 no Most common asymptomatic type Initial presentation is tendon tear Mucoid patches & vacuoles intersperse between thinned tendon fibers MRI Mucoid deposits are hyperintense on T1 & PD Interrupted irregular increased signal on T2 & STIR JAAOS 2009; 17 (1): 3-14 Fatty deposits in tendon Does not predispose to tear Age dependent Related to xanthofibromatosis Nodular thickening Low to intermediate signal on all sequences enhances Patients with familial hyperlipidemia Focal/diffuse increased intratendinous signal T1 & T2 Marked thickening Bilateral DDx: tendon infiltration related to amyloid & gout 3

4 Amyloid Achilles thickening & ossification, ossification in Kager s fat pad and joints FAOJ.org ISMRM Dystrophic calcification Cortical bone & trabeculae form Chronic, repetitive trauma with microtears Ballet dancers, runners, jumping athletes RA, seronegative arthropathies Haglund deformity MRI Tendon thickening at insertion Loss of concavity along anterior margin Intratendinous increased signal Soft tissue edema Edema in adjacent calcaneal tuberosity Retrocalcaneal bursitis Summerdoc.blogspot 4

5 Men years old, leisure athletics involving concentric loading (basketball, tennis) Most common at watershed region (critical zone) Systemic disease (RA, gout, lupus, DM) & fluoroquinolones Interstitial myxoid degeneration Longitudinal orientation, surrounding fibers intact Linear increased T1, PD, T2 signal Partial incomplete interruption of fibers Torn fibers may partially retract Frayed, corkscrew, heterogeneous high signal on fluid sensitive sequences radrounds, Cabanillas Complete tears high signal, fluid-filled gap Distracted or overlapping fibers Intratendinous & peritendinous edema when acute Palpable defect, loss of plantar flexion Determines surgical repair of complete & partial tears Based on size of gap Type I: partial tear, 50% or less Type II: complete tear, gap <3cm Type III: complete tear, gap 3-6cm Type IV: complete tear, gap >6cm Type I & II: end-to-end anastomosis Type III: autogenous tendon graft flap Type IV: free tendon graft or synthetic graft AJR 2013;200:

6 Inflammation of connective tissue peritenon that surrounds tendon High T2 signal around tendon (mostly posterior) Inflammation of pre-achilles (Kager) fat pad High T2 signal, edema, irregularity in fat pad along tendon (anterior) AJR 2013;200: AJR 2013;200: Superficial posterior muscle compartment Tendon courses obliquely between the gastrocnemius and the soleus (S), along deep medial aspect of Achilles Inserts to distal Achilles on medial aspect of calcaneal tuberosity Action: Minor role in knee flexion and foot plantar flexion DDx: Partial tear medial head gastrocnemius Deep posterior muscle compartment Tendon forms lower 1/3 of calf Passes posterior to medial malleolus (TDnH) along medial calcaneus via tarsal tunnel Divides into several fascicles 1 insert: navicular tuberosity 3 cuneiforms 2,3,4 metatarsal bases Cuboid Normal diameter 2x flexor digitorum longus tendon AJR. 2000;175:

7 Action Strongest invertor of foot Maintains longitudinal arch Dynamic stabilizer Spring ligament is static stabilizer Aids in ankle plantar flexion, forefoot adduction Black without any internal signal intensity Prone to magic angle artifact as it curves around the medial malleolus Small amount of fluid in the synovial sheath of the posterior tibialis tendon is normal No more than 1-2 mm Almost never circumferential No normal sheath around the distal PTT, fluid observed at the distal 1-2 cm is abnormal and related to the metaplastic synovium AJR. 2000;175: Abnormal size may be the only indicator of tendon dysfunction Normal posterior tibialis tendon is roughly twice the size of the two adjacent tendons (FDL, solid straight arrow) PTT should be slightly smaller than the anterior tibialis tendon PTT should be slightly smaller than the summated measurements of the peroneus brevis and peroneus longus tendons (curved arrow) 20-year-old healthy man T1FS Stress reaction re accessory navicular (types 2 & 3) Tendon dysfunction/failure Doesn t typically rupture, but becomes dysfunctional Associated with stretching of spring ligament Progressive, painful flat foot deformity Hindfoot valgus Over pronation with collapse of medial longitudinal arch Type I tears Interstitial tearing Increased size Type II tears Decreased diameter, equal to or less than that of the flexor digitorum longus tendon Type III tears Complete rupture of the tendon AJR. 2000;175: Axial T2 FS: posterior tibialis tendon with multifocal speckled internal signal intensity surrounded by excessive synovial fluid (arrow) AJR. 2000;175: AJR. 2000;175:

8 Thickening, synovitis, & internal signal intensity (white arrow) Diameter of the PTT increased as much as 5 10x the diameter of the adjacent flexor digitorum longus tendon Normal diameter is approximately 2x that of the flexor digitorum longus tendon T1 T2FS AJR. 2000;175: T2 Abnormally small PTT (white arrow) equal to or less than that of the flexor digitorum longus tendon T2FS nearly fluid-filled posterior tibial tendon sheath (arrow), with only a few edematous irregular tendon fibers Enlarged posterior tibialis tendon with linear signal splitting posterior tibialis tendon into fascicles (arrow) Strong association Important secondary sign of tendon disease Fluid or edema within the sinus tarsi obliterates the normal fat signal intensity surrounding the interosseous and cervical ligaments Sag T1: loss of fat signal in the sinus tarsi (arrow) in this patient who also had a type I PTT tear at the medial malleolus AJR. 2000;175:

9 Spring ligament abnormalities have high association (92%) with advanced posterior tibial tendon injury Spring ligament runs deep to PTT, and contiguous with the deltoid ligament superiorly (Tibiospring ligament) Thickening & increased fluid signal intensity within the spring ligament (arrows) consistent with tear is noted in this patient with a proximal PTT tear (not shown) 4% of the population Present in a much higher percentage of patients with PTT disorders PTT inserts onto the accessory navicular Accessory navicular or a cornuate navicular is risk factor for PTT tears (most people with an accessory or cornuate navicular will not have a disorder of the posterior tibialis tendon) 30-year-old man at risk for posterior tibialis dysfunction. Axial T2FS: hypertrophy of navicular tubercle (arrow), consistent with cornuate navicular. AJR. 2000;175: Unfused accessory navicular ossicle (normal variant) Type 1(os tibiale externum) Small, round, completely separate Not associated with tendon dysfunction Type 2 Joined to navicular bone via synchondrosis or syndesmosis Tendon inserts on ossicle Abnormal stress at junction of ossicle and navicular bone Type 3 cornuate navicular Osseous fusion of type 2 Prominent medial tubercle Tendon inserts more proximally & at steeper angle 28-year-old man at risk for posterior tibialis dysfunction Sagittal T2 Accessory navicular (a) Normal low signal intensity between accessory navicular and native navicular (curved arrow) Straight line (instead of normal smooth curve) that posterior tibialis tendon makes as it extends from medial malleolus. This abnormality causes focal point of friction at medial malleolus (straight arrow). Axial PD Accessory navicular with low-signalintensity synchondrosis (arrow). AJR. 2000;175: Fluid between navicular and accessory navicular Edema in both bones (arrows) representing altered mechanics AJR. 2000;175: AJR. 2000;175:

10 Deep posterior muscle compartment Passes post to medial malleolus between PT and FHL Crosses FHL at master knot of Henry Tendon divides into 4 slips Inserts base 2-5 distal phalanges Action: flex 2 nd 5 th metatarsals & phalanges, ankle, invert foot FDL tendon crosses superficially over the FHL in the plantar midfoot at the knot of Henry Usually located near navicular and medial cuneiform Fibrous slip connects the FHL and FDL at the knot of Henry Tendon sheaths of the FHL and FDL usually communicate allows inflammation of one structure to spread to the adjacent tendon Deep posterior muscle compartment Passes through fibro-osseous tunnel between medial and lateral tubercles of posterior process of talus Along medial malleolus and tarsal tunnel Below sustentaculum tali Crosses FDL at master knot of Henry Inserts distal phalanx great toe Predisposed to tendinosis, tenosynovitis, partial & complete tears (overuse related) Action: plantar flex great toe IP & MTP, ankle 10

11 Common in ballet dancers Constant repetitive plantar flexion (overuse injury) Tendinosis & tenosynovitis Trigger toe (stenosing tenosynovitis) Focal tendon enlargement Tendinosis, partial ruptures Entrapment in fibro-osseous tunnel along medial calcaneus Results in snapping & locking of toe in flexion or extension AJR. 2001;176: Originate along posterior fibula Posterior to lateral malleolus via common peroneal tunnel Common synovial sheath Brevis anteromedial to longus Retromalleolar groove is small sulcus near fibula tip Contained in groove by superior peroneal retinaculum Retinaculum attaches to calcaneus with calcaneofibular ligament Pass along lateral calcaneus Separated by peroneal tubercle (small bony prominence) Via 2 nd fibro-osseous tunnel Covered by inferior peroneal retinaculum Brevis inserts base of 5th metatarsal Action: everts and dorsiflexes ankle Injury: Distal fibula (forcibly compressed during inversion injury) Longus sharp turn under calcaneocuboid joint, inserts base of 1 st metatarsal and medial cuneiform Action: plantar flex ankle Injury: Along peroneal tubercle or at cuboid tunnel

12 Tendinopathy associated with lateral ligament injuries Injury results in loss of eversion Longitudinal split tear of peroneus brevis Subluxation/dislocation Peroneus brevis may avulse from base of 5 th MT Large peroneal tubercle with peroneus longus tendinosis Os peroneum Most common lateral tendon injury PB tendon thin, may be separated by anteriorly displaced peroneus longus Separates brevis & longus Enlarged Longus tendon injury Tendon sheath inflammation radsource.us 12

13 Peroneus longus dislocated lateral to the fibula Peroneus brevis remains located Superior peroneal retinaculum (green arrowheads) is laterally displaced Shallow peroneal groove predisposes Absent retromalleolar groove (20%) Lateral calcaneal osseous prominences Peroneal tubercle (ant) (40%) Retrotrochlear eminence (post) (98%) Peroneus quartus muscle (20%) Os peroneum Flat or convex posterodistal fibula Predisposes to tendon subluxation radsource.us 13

14 Insertion of peroneus quartus muscle (normal variant) Peroneus quartus (PQ) arises from the peroneus brevis muscle (PB) Courses medial and posterior to the peroneus longus (PL) and peroneus brevis (PB) muscles and tendons Inserts on retroctrochlear eminence of the calcaneus radsource.us T1: fleshy accessory peroneus quartus muscle (arrows) coursing posterior to the peroneal longus (PL) and peroneus brevis (PB) tendons and inserting onto the retrotrochlear eminence of the calcaneus (asterisk) Complete tear distal PL tendon with proximal displacement of os proximal to calcaneocuboid joint (rare) Sesamoid bone in peroneus longus (at cuboid tunnel) Always present but ossified in only 20% Mass effect in peroneal groove Mimics longitudinal split of peroneus brevis Empty sheath Os Peroneum Stress Reaction with associated PL Tendinopathy and tenosynovitis X-ray: sclerotic or fragmented os 14

15 Deep anterior muscle compartment Under superior extensor retinaculum at ankle (THnD) Under inferior extensor retinaculum Inserts medial cuneiform & 1 st metatarsal base Action: main dorsiflexor of ankle Typically tears completely and retracts Tender mass above ankle joint Elderly patients, minor or no trauma Tendinopathy Extreme focal tendon enlargement Courses lateral to tibialis anterior Inserts dorsal base 1 st distal phalanx Action: dorsiflex IP & MTP joints, foot eversion Courses lateral to EHL Inserts dorsal base 2 nd -5 th distal phalanges Action: dorsiflex IP & MTP joints, foot eversion 15

16 Lateral Complex Anterior talofibular Calcaneofibular Posterior talofibular Medial Complex (Deltoid Ligaments) Superficial Deep Syndesmosis Anterior Inferior Tibiofibular Posterior Inferior Tibiofibular (Inferior transverse tibiofibular) Inferior Interosseous Ligament (membrane) Spring (Calcaneonavicular) Ligament Complex Superomedial Calcaneonavicular Ligament Medioplantar Calcaneonavicular Ligament Inferoplantar Calcaneonavicular Ligament Improves visualization of ankle ligaments Lateral Syndesmotic Analyzing soft tissue impingement syndromes AMA Classification of Ligamentous Sprain Grade Ligament Injury 1 Stretched Ligament 2 Partial tear 3 Complete Rupture Discontinuity/attenuation Thickening Heterogeneity Wavy appearance Poorly defined margins Periarticular edema Fluid in adjacent tendon sheaths and extravasating outside joint capsule MRI rarely indicated in acute setting Injuries initially treated conservatively Adapted from Rachun A Standard Nomenclature of Athletic Injuries. Chicago, American Medical Association,

17 Indistinct margins improve Defect fills with fibrous scar Replaced by thickened band inseparable from joint capsule Periarticular edema Up to 6 months Lateral sprain is most common ankle injury in athletes Mechanism: plantar flexion, inversion, internal rotation Associated injuries Syndesmotic ligaments Deltoid ligament Sinus tarsi ligaments Anterior Talofibular Ligament (ATAF) Inserts anterior to lateral talar articular facet Weakest, most frequently injured Calcaneofibular Ligament (CF) 2 nd most frequently injured Peroneal tendons just superficial to CFL Posterior Talofibular Ligament (PTAF) Usually sequentially injured anterior to posterior Eorthopod.com Weakest of lateral ligaments 2/3 of ankle sprains are isolated ATAF injury Midsubstance rupture or avulsion Anterolateral malleolar tip to talar neck, stabilizing talus Well visualized on fluid-sensitive sequences (axial T2) Uninjured ligament is of uniform thickness and low T1 and T2 signal intensity (arrow) 17-year-old boy with remote ankle injury Thickened ligament Increased internal signal (arrowhead) T2 Axial 17-year-old boy with recent injury Axial T2-weighted image Discontinuous ligament Surrounded by extensive fluid signal (arrow) 17

18 Meniscoid lesion Hyalinization of tissue in anterolateral recess Injury of ATAF Contributes to anterolateral Impingement 19-year-old woman with continued ankle pain after sprain Nodular soft tissue occupying anterolateral gutter (arrow) Torn anterior talofibular ligament, seen in more distal image, is not included T2 Usually torn in conjunction with ATAF Lies deep to peroneal tendons Extends from lateral malleolar tip to trochlear eminence, stabilizing subtalar joint Often partially imaged in coronal or axial planes; multiple images are often needed to visualize its entire course Oblique axial proton density weighted image of intact calcaneofibular ligament (arrow) shows regular contour and homogeneously low signal 24-year-old man with Weber type B fracture of fibula Fluid signal in ligament Mildly irregular contour (arrowhead) 41-year-old woman with ankle trauma Discontinuous ligament Adjacent fluid signal (arrow) Distal ligament at its calcaneal insertion (asterisk) Associated peroneal tendon/sheath/posterior retinaculum injury T2 T2 Least frequently injured Extending from posterior talus (lateral tubercle) to fibular malleolar fossa Normal posterior talofibular ligament (arrow) has linear striations (fibrofatty composition) Axial PD 18

19 17-year-old boy with recent injury Complete tear of posterior talofibular ligament: ligament defect Torn ends of discontinuous ligament are surrounded by fluid signal (arrow) T2 Triangular fibers with apex at medial malleolus Deep ligaments Deep anterior and posterior tibiotalar ligaments Talar attachments Cross one joint Superficial ligaments Tibionavicular, tibiospring, tibiocalcaneal, superficial posterior tibiotalar ligaments insert on navicular tuberosity, sustentaculum tali, talus Cross two joints (ankle joint and talonavicular or subtalar joint) Most commonly seen on MRI Tibiospring (superficial) Tibionavicular (superficial) Posterior tibiotalar (deep) Primary stabilizer against excessive valgus tilt of the talus Injured via eversion or abduction force Isolated injuries rare Associations Malleolar fractures Lateral ankle sprains Syndesmotic diastasis Posterior tibial tendon dysfunction Widened Medial Clear Space (X-ray) 4mm Related to deep deltoid ligament injury Acute tear Fascicular disruption Heterogeneity Increased signal Loss of normal striation (deep) Contusion Increased interstitial signal Chronic Thickening Attenuation Tibionavicular ligament Inserts onto navicular Visible on only 55% of MR images of asymptomatic subjects unreliable in assessing ligament injury Intact tibionavicular ligament (arrow) Tibiospring ligament Connects medial malleolar colliculus to superomedial spring ligament Intact tibiospring ligament with attachment to spring ligament (arrow) Coronal PD Coronal T2 19

20 Coronal T2 20-year-old woman with Weber type B fracture Coronal T2-weighted image Complete tear of tibiospring ligament Discontinuous, irregular fibers (arrow) Posterior tibiotalar ligament Thickest of medial ligaments Intervening fat separating its fascicles, resulting in striated appearance in normal ligament Intact posterior tibiotalar ligament Continuous fibers Intervening fat between fascicles (arrow) Coronal T2 Coronal T2 Fascicular disruption, irregularity, and loss of striation are indicators of injury Partial tear of posterior tibiotalar ligament Irregular contour Disrupted fibers with fluid signal near its talar attachment (arrow) Complete disruption of posterior tibiotalar ligament Irregular contour of visible fibers, none of which appears attached at its talar insertion (arrowhead) Interosseous Ligament Thickened distal portion of interosseous membrane Syndesmotic recess Triangular defect distally Normal height 0.5cm on MRI Anterior (AITF) & Posterior (PITF) Inferior Tibiofibular Ligaments Anterior weaker Posterior avulsion more common than ligament injury Transverse Ligament (Posterior Intermalleolar Ligament) Lateral malleolus to posterior articular margin of tibia Anterior to PITFL 20

21 May be isolated Associated with Weber B & C fractures Lateral & medial collateral ligament injuries High impact activities Requires longer recovery time Surgery indicated if diastasis Wagstaffe fracture Vertical fibular fracture AITF ligament avulsion Associated with ankle diastasis & syndesmosis injury MRI syndesmotic interruption Ligament Discontinuity Contour alterations Nonvisualization Tibiofibular recess Increase in height 1.2cm acute tears 1.4cm chronic tears Extends from anterior tibial tubercle to fibular tubercle Best visualized on axial images Normal AITF ligament may show fascicular appearance, which should not be confused with injury or tear Intact anterior inferior tibiofibular ligament is low in signal intensity (arrow) 19-year-old man with right-ankle pain after injury Fluid signal in thickened, irregular ligament (arrowhead) PD T2 21

22 44-year-old man with high fibular fracture Discontinuous ligament (arrow) PD Extends from posterior tibial tubercle to posterior fibula Most inferior fascicles (not shown) comprise inferior transverse ligament Intact posterior inferior tibiofibular ligament (arrow) is seen on axial proton density weighted image 44-year-old man with high fibular fracture Complete tear of posterior inferior tibiofibular ligament on axial T2 Discontinuous ligament (arrow) Posterior Intermalleolar Ligament Normal variant Visible on 19% of clinical MR studies Lies anterior to PITFL, posterior to posterior talofibular ligament Strong, thick band of fibers passes transversely across the posterior ankle joint, from lateral malleolus to posterior tibia, near medial Projects below the margin of the bones, and forms part of the articulating surface for the talus Associated with posterior impingement syndrome TrTFL is partly visualized as a thick hypointense band posterior to the talar dome (arrow). 22

23 Inferior most portion of interosseous membrane Connects medial fibula to lateral tibia Inferior margin lies adjacent to tibiofibular recess, lined with synovium Tibiofibular recess extends superiorly 5 mm from joint line on MR images of healthy subjects When fluid signal extends more than 12 mm into tibiofibular recess, syndesmotic injury should be considered Intact interosseous ligament or membrane is seen on coronal T2-weighted image. Note absence of fluid in tibiofibular recess (arrows). 44-year-old woman with ankle pain Coronal T2-weighted image Fluid signal extends into tibiotalar recess 13 mm superior to joint line (arrow), indicating high likelihood of interosseous ligament or membrane tear Plantar calcaneonavicular ligament Fibrocartilagenous complex Talar head rests on articular surface (acetabulum pedis) Three components Superomedial calcaneonavicular ligament (smcnl) Most medial, widest, strongest Most common tear Sustentaculum tali to superomedial navicular Medioplantar oblique CNL (mpocnl) Inferoplantar longitudinal CNL (iplcnl) Helps stabilize plantar arch (static) Associated with posterior tibial tendon dysfunction Contiguous with deltoid ligament of ankle Extends from calcaneus to navicular tuberosity Superomedial calcaneonavicular (Sp1) Medioplantar oblique calcaneonavicular (Sp2) Inferoplantar longitudinal calcaneonavicular (Sp3) Tibiospring ligament (M3) belongs to superficial layer of medial complex and is included here to show its insertion to superomedial calcaneonavicular ligament. Commonly associated with degenerative flatfoot deformity PTT dysfunction Rheumatoid arthritis Diabetic arthropathy Isolated injury rare (traumatic) Symptoms Medial/dorsal pain Perceived instability Acquired progressive planovalgus foot deformity Inconsistent visualization Subtle signal heterogeneity Abnormal caliber Thickened (5-6.5mm) Associated with PTT dysfunction Disrupted or attenuated ligament Markedly pronated talar head 23

24 Best seen on coronal or transverse oblique images Low signal Wraps medially around talar head Deep to PTT (blue arrow) Striated (interposed fat) Obliquely oriented Best seen on sagittal, axial, transverse oblique Best seen on coronal and sagittal Short, intermediate signal Originates: sustentaculum tali of calcaneus Inserts: superomedial tarsal navicular Deep to posterior tibial tendon (PTT) Superficial surface of superomedial calcaneonavicular ligament is composed of fibrocartilaginous gliding zone Most likely to be injured PTT dysfunction is often associated with spring ligament injury. Coronal T2-weighted image shows intact superomedial calcaneonavicular ligament (straight arrow) and adjacent PTT (curved arrow). Normal tibiospring ligament is also visible (arrowhead). Asterisk indicates fibrocartilaginous gliding zone. Axial T2-weighted image shows normal contour and homogeneously low signal in superomedial calcaneonavicular ligament (arrowhead). 50-year-old man with foot and ankle pain Oblique axial T2-weighted image Abnormally thickened, irregular superomedial calcaneonavicular ligament contains bright fluid signal 24

25 Coronal PD fat sat: Abnormal thickening and increased signal intensity of the distal posterior tibial tendon (arrow). Superomedial portion of the calcaneonavicular (spring) ligament is diffusely thinned and attenuated (arrowheads). T2-weighted axial oblique: Thickened posterior tibial tendon with partial tear along the deep surface (arrow). Superomedial portion of the calcaneonavicular (spring) ligament is diffusely thinned (arrowheads) and torn distally at the navicular insertion (small arrow) Extends from medial portion of navicular bone to calcaneal coronoid fossa Best visualized in axial plane. Normal striated appearance of uninjured medioplantar oblique calcaneonavicular ligament is shown on axial T2-weighted image (arrow). 50-year-old man with foot and ankle pain Axial T2-weighted image Irregular, wavy contour of ligament Interruption at its calcaneal attachment (arrow) Lies anterior to medioplantar oblique calcaneonavicular ligament Extends from inferior navicular bone to calcaneal coronoid fossa Thickest of three components of spring ligaments Seen in 91% of asymptomatic subjects Sagittal T1-weighted image shows intact inferoplantar longitudinal calcaneonavicular ligament (arrow) 25

26 Linear high frequency transducer (8-12MHz) Doppler (hyperemia associated with tendinosis & tenosynovitis) Normal Echogenic, fibrillar architecture Scant vascularity Must orient 90 to tendon axis to avoid anisotropic artifact Hypoechoic Mimics tendon tears Most common as tendons curve around malleoli Distal Achilles Trans peroneus longus & brevis Long Flexor hallucis longus Long peroneus longus Tendinosis Expansion early Loss of normal fibrillar architecture Chronic: thinning of tendon Partial tear Focal linear discontinuity of tendon Tenosynovitis Fluid in sheath Hyperemia Thickened synovium Rupture of the proximal peroneal retinaculum with instability of the tendons. The peroneal tendons are inhomogeneous and thickened Healio Orthopedics: July Volume 33 Issue 7: Full thickness Achilles tendon rupture Achilles tendon rupture with an organized hematoma in the defect, but there is no continuity of the tendon fibers

27 Tenosynovitis and intratendinous ruptures of the peroneal tendons. The longus is nestled within the peroneal brevis tendon Tendinosis of the Achilles tendon and a peritendinitis with a hypoechoic halo and hyperechoic Kager s fat with hypervascularity High frequency probe (14-15 MHz) Intact Ligament Parallel-layered echogenic structure Well-defined sharp margins Subject to anisotrophy Ligaments become hypoechoic if US beam is not perpendicular to fibers Acute Ligament Injury Thickened Anechoic zone (hematoma or edema) Anechoic band surrounding ligament (edema) Avulsion at bony inserts Chronic Ligament Injury Thickened, hypoechoic Bony irregularities Abnormal lengthening Moderately thickened and hypoechoic ATAF. Anterior Talofibular Ligament Calcaneofibular Ligament Discontinuity of the ATAF with fluid surrounding the torn ends (arrow) AJUM November 2009; 12 (4):10-17 AJUM November 2009; 12 (4):10-17 Review pertinent anatomy Discuss typical appearance of injured ligaments & tendons Consider commonly associated injuries Recognize injury patterns Ankle Ligaments on MRI: Appearance of Normal and Injured Ligaments. AJR 2009; 193: Healio Orthopedics: July Volume 33 Issue 7: Bencardino JT., Rosenberg ZS, Serrnao LF. MR Imaging of Tendon Abnormalities of the Foot and Ankle. MRI Clinics Aug 2001, vol. 9 no. 3 pp Pomeroy GC, Pike RH, Beals TC, Manoli A. Acquired flatfoot in adults due to dysfunction of the posterior tibial tendon. J Bone Joint Surg Am 1999;81-A: Balen P, Helms C. Association of posterior tibial tendon injury with spring ligament injury, sinus tarsi abnormality, and plantar fasciitis on MRI Imaging. AJR2001; 176: L. R. Toye, C. A. Helms, B. D. Hoffman, M. Easley, and J. A. Nunley MRI of Spring Ligament Tears Am. J. Roentgenol., May 1, 2005; 184(5):

28 MR Imaging of Disorders of the Posterior Tibialis Tendon. AJR. 2000;175: MR Imaging Findings of Entrapment of the Flexor Hallucis Longus Tendon. AJR. 2001;176: