Ankle impingement syndromes - pictorial review.

Ankle impingement syndromes - pictorial review. Poster No.: P-0148 Congress: ESSR 2015 Type: Educational Poster Authors: R. D. T. Mesquita, J. Pinto, J. L. Rosas, A. Vieira ; Porto/PT, 1 2 2 3 1 1 3 Matosinhos/PT, Senhora da Hora/PT Keywords: Musculoskeletal system, Musculoskeletal joint, Musculoskeletal bone, Conventional radiography, CT, MR, Diagnostic procedure, Imaging sequences, Athletic injuries, Trauma, Arthritides DOI: 10.1594/essr2015/P-0148 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 25

Learning objectives To review the classification of ankle impingement syndromes. To discuss and illustrate the different imaging findings. Page 2 of 25

Background Ankle impingement syndromes are defined as pathologic conditions resulting in chronic, persistent painful limitation of full range of motion at the tibiotalar articulation secondary to soft-tissue or osseous abnormalities. The leading cause of impingement lesions is posttraumatic injuries, usually ankle sprains. This condition occurs more commonly in active people and athletes probably because repetitive subclinical microtrauma is an important basis mechanism. The syndromes are usually classified according to its anatomic relationship to the tibiotalar joint as anterolateral, anterior, anteromedial, posteromedial or posterior impingement. Magnetic resonance is particular valuable for identifying other causes of persistent ankle pain that may coexist or mimic ankle impingement, such as intraarticular bodies, cartilage lesions, occult fractures, tendon abnormalities and ankle instability. Regardless of the type of impingement, the treatment is usually similar. The initial treatment includes conservative measures such as physiotherapy or nonsteroidal antiinflammatory drugs. (NSAIDs), but when these fail, arthroscopic examination is indicated to identify and resect the impinging lesion. Anterolateral Impingement Most common soft-tissue impingement Usually secondary to an inversion mechanism of injury Repetitive microtrauma and subclinical microinstability may lead to soft-tissue abnormalities Page 3 of 25

Abnormalities located in the anterolateral gutter (boundaries: anterior - anterioinferior tibiofibular (AITFL) and talofibular (ATFL) ligaments; medial - talus; lateral - fibula; superior - tibial plafond and syndesmosis; inferior - calcaneofibular ligament) Pathologic changes: 1. 2. 3. Partial or complete tear of AITFL or ATFL Intra-articular hemorrhage Reactive synovial hyperplasia and scarring Synovial tissue in advanced synovitis may become molded to a triangular shape in the anterolateral gutter described as a "meniscoid lesion" Accessory ligament or distal fascicle of AITFL (Bassett's ligament) is a normal variant fascicle separated from AITFL by a fibrofatty septum that can cause impingement when thickened There is no associated ligamentous ankle instability Anterior Impingement Common cause of chronic ankle pain, especially in ballet dancers and soccer players Osseous outgrowths at the anterior ankle joint are a major component The spur results in decreased angle between tibia and talus, measuring less than 60 Hypertrophied synovial tissue can also occur Possible mechanisms: 1. 2. Forced dorsiflexion results in repeated microtraumas leading to microfractures of trabecular bone or periosteal hemorrhage that can result in osteophytes formation Forced plantar flexion trauma can cause capsular avulsion injury and lead to enthesophyte formation Page 4 of 25

Clinical features: anterior ankle pain with limited and painful dorsiflexion Anteromedial Impingement Relatively rare ankle impingement Probable mechanism: complication of an inversion injury associated with repeated microtrauma lead to anteromedial capsular thickening and synovitis in the region of the anterior tibiotalar ligament Most commonly associated with lateral and medial ligamentous injury Osteophytes are an important feature Clinical features: anteromedial pain that is exacerbated by dorsiflexion Posteromedial Impingement Rare form of impingement Most commonly a sequel of severe inversion injury Pathologic changes: hypertrophic changes and fibrosis of the posteromedial tibiotalar capsule and posterior deltoid fibers Associated injuries: articular cartilage and ligamentous tears Clinical features: posteromedial pain between medial wall of the talus and posterior margin of medial malleolus Initially symptoms from the lateral ligament disruption may obscure Main differential diagnosis for posteromedial ankle pain includes posterior tibial tendon abnormalities Page 5 of 25

Posterior Impingement Known as "os trigonum syndrome" More common in ballet dancers and soccer players Repetitive or acute forced plantar flexion leads to compression of bone and soft tissues at the posterior ankle between the tibia and the calcaneus Osseous and soft-tissue anatomic variants that predispose to this condition: 1. Prominent os trigonum 2. Prominent lateral talar process (Stieda process) 3. Posterior intermalleolar ligament 4. Superior prominence of the calcaneal tuberosity 5. Downward sloping posterior lip of the tibia Pathologic changes: Inflammation of the soft tissues and/or osseous injury of the posterior ankle o Osseous injuries include: Fracture, fragmentation, and pseudoarthrosis of the os trigonum or lateral talar tubercle o Significant soft-tissue abnormalities: Synovial thickening along the posterior capsule Thickening of the posterior intermalleolar or talofibular ligaments Flexor hallucis longus (FHL) tenosynovitis Clinical features: Page 6 of 25

1. 2. 3. Pain and tenderness along the posterior ankle Usually insidious development of symptoms related to repetitive athletic activity that requires plantar flexion Severity of symptoms not associated with presence or size of either os trigonum and lateral tubercle of the talus Page 7 of 25

Imaging findings OR Procedure Details Although other imaging modalities can be useful for assessing ankle impingement MR imaging is the most useful imaging method for detecting the osseous and soft-tissue abnormalities and can also exclude additional potential causes of chronic ankle pain. Anterolateral Impingement MRI is essential to exclude abnormalities other than soft-tissue impingement and to assess patients with an uncertain clinical diagnosis. Intermediate to low-signal synovial hypertrophy and scarring in the anterolateral gutter - better visualized in axial T1 and fluid-sensitive images Associated findings: 1. 2. 3. Thickening of the ATFL Displacement of normal fat anterior to the fibula Nodular or irregular contour of the anterolateral recess Anterior Impingement Radiographs enable evaluation of the spurs and the tibiotalar joint space, simultaneously important for diagnosis and preoperative planning MRI findings: 1. 2. 3. 4. Spurs along the anterior tibial rim, medial lateral malleolus, or talar neck Synovitis and soft-tissue thickening in the anterior recess often present Allows diagnosis of cartilage lesions Marrow edema is uncommon Anteromedial Impingement Role of MRI not yet established MRI findings: Page 8 of 25

1. 2. 3. Scarring Synovitis Capsular and anterior deltoid thickening and ossification Subtle capsular changes may not be depicted MR arthrography is possibly the imaging method of choice Posteromedial Impingement MRI features of posteromedial impingement are not specific MRI is especially important to exclude concomitant injuries. MRI acute/subacute possible findings (first 4 weeks): Increased signal in the posteromedial capsule Increased signal or disruption in the posterior tibiotalar ligament (PTTL) Displacement of PTT and flexor digitorum longus tendons MRI chronic possible findings: PTTL disruption Abnormal signal encasing or abutting the PTT and flexor digitorum longus tendons Marrow edema (uncommon) Posterior Impingement Radiographs can be used to identify osseous anatomic variants CT allows accurate assessment of osseous changes such as fragmentation of the ossicle and erosions along the talus MRI findings: Page 9 of 25

1. 2. 3. 4. 5. Synchondrosis anomalies including opposing marrow edema or fluid signal related to motion. Soft-tissue abnormalities such as: posterior capsular thickening ligament disruption FHL tenosynovitis soft-tissue edema and synovitis IV gadolinium administration may improve detection of small focal areas of synovitis. Page 10 of 25

Images for this section: Fig. 1: 45-year-old woman with history of ankle ligament instability and anterolateral impingement. Axial T2-weighted image shows low-signal-intensity meniscoid-shaped mass (arrow) extending from thickened anterior talofibular ligament into lateral gutter. Page 11 of 25

Fig. 2: 34-year-old woman with anterolateral impingement. Axial T2-weighted image shows low-signal-intensity thickened anterior talofibular ligament (arrow) in the lateral gutter. Page 12 of 25

Fig. 3: 38-year-old woman with anterior bone and soft-tissue impingement. A, Sagittal T1weighted image shows spurs projecting from dorsal talar neck (arrow) and from anterior distal tibia (arrowhead). Page 13 of 25

Fig. 4: 38-year-old woman with anterior bone and soft-tissue impingement. B, Sagittal inversion-recovery weighted image shows talar neck marrow edema (arrow) and intraarticular soft-tissue scarring (arrowhead). Page 14 of 25

Fig. 5: 25-year-old man with anterior bone and soft-tissue impingement. A, Sagittal T1-weighted spin-echo MR image of left ankle shows anterior tibial (arrow) and talar (arrowhead) osteophytes ("kissing lesion") Page 15 of 25

Fig. 6: 25-year-old man with anterior bone and soft-tissue impingement. B, Axial fatsuppressed proton density-weighted image reveals dorsal talar osteophyte (arrow) and focal synovitis in anterior capsular recess of tibiotalar joint (arrowhead). Page 16 of 25

Fig. 7: 43-year-old man with anteromedial and posteromedial impingement. A, Axial proton density-weighted image shows synovitis (arrow) in anteromedial gutter deep to superficial anterior deltoid fibers. Synovitis extends posteriorly between flexor digitorum longus and posterior tibial tendons, suggesting concomitant posteromedial impingement. Page 17 of 25

Fig. 8: 43-year-old man with anteromedial and posteromedial impingement. B and C, Sagittal (B) and coronal (C) T1-weighted images shows thickening of anterior deep and superficial deltoid fibers. Changes extend posteriorly, suggesting concomitant posteromedial impingement. Page 18 of 25

Fig. 9: 43-year-old man with anteromedial and posteromedial impingement. B and C, Sagittal (B) and coronal (C) T1-weighted images shows thickening of anterior deep and superficial deltoid fibers. Changes extend posteriorly, suggesting concomitant posteromedial impingement. Page 19 of 25

Fig. 10: 37-year-old man with posteromedial impingement. Axial T2-weighted image depicts marked scarring and loss of normal architecture of deep tibiotalar component of deltoid ligament (arrow). Medial displacement of posterior tibial tendon (asterisk) and obliteration of fat planes between posterior tibial tendon and scarred ligament are shown. Page 20 of 25

Fig. 11: 30-year-old man with posterior impingement. A, Sagittal T1-weighted image shows low-signal-intensity os trigonum (arrow) and adjacent low-signal soft-tissue abnormality (arrowhead). Page 21 of 25

Fig. 12: 30-year-old man with posterior impingement. B, Sagittal fat-suppressed proton density-weighted MR image shows opposing talar and os trigonum marrow edema (arrows), adjacent soft-tissue edema (arrowhead), and joint effusion (asterisk). Page 22 of 25

Fig. 13: 37-year-old man with posterior impingement. Sagittal fat-suppressed proton density-weighted (A) and axial fat-suppressed T2- weighted MR (B) images of ankle shows abnormal high signal intensity in os trigonum and posterior distal tibia (arrows) with associated tenosynovitis of flexor hallucis longus (arrowhead). Page 23 of 25

Fig. 14: 37-year-old man with posterior impingement. Sagittal fat-suppressed proton density-weighted (A) and axial fat-suppressed T2- weighted MR (B) images of ankle shows abnormal high signal intensity in os trigonum and posterior distal tibia (arrows) with associated tenosynovitis of flexor hallucis longus (arrowhead). Page 24 of 25

Conclusion Imaging allows evaluation of patients with uncertain clinical diagnosis and is essential to determine the anatomical site where the conflict takes place, permitting recognition of the cause of impingement. MRI is useful to confirm the diagnosis and assess for other possible pathologic conditions that can mimic or coexist with impingement syndromes Page 25 of 25