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Ankle Impingement Syndrome
• initial ankle injury
• abnormal osseous & soft tissue thickening in the subacute or chronic situation
• chronic ankle pain , painful limitation of ankle movement
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Ankle Impingement Syndrome
• Anterolateral Impingement
• Anterior Impingement
• Anteromedial Impingement
• Posterior Impingement
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Anatomy and Causes
secondary ossification center :
- 7-13 years, usually fuses within 1 year- large lateral talar process (Stieda process)- failure of fusion (os trigonum)
Posterior Impingement
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Anatomy and Causes
compression of soft tissue between posterior process of calcaneus and posterior tibia on plantar flexion of ankle
lateral posterior process of talus
os trigonum
chronic injury repetitive forced plantar flexion (usually)
acute injury avulsion fx of PTaF ligament, talar fx disruption of os trigonum
Posterior Impingement
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Lateral talar tubercle
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Os trigonum
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Clinical features posterior ankle pain
exacerbated by plantar flexion or dorsiflexion
posterior tenderness anterior to and not involving Axchilles tendon
palpable soft tissue thickening
Posterior Impingement
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Imaging features : Plain, CT, US prominent lateral talar process or os trigonum
fracture not evident on plain radiography
symptomatic os trigonum :↑ activitynegative scan excludes this diagnosis
Posterior Impingement
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Imaging features : MRI bone abnormality
bone marrow edema in lateral talar tubercle or os trigonumfracture line or fluid in synchondrosis (os trigonum fracture)
posterior capsular or ligament thickeninglow to intermediate SI on T2-WI
Synovitis posterior synovial recess of subtalar and tibiotalar joint FHL tendon sheath
Posterior Impingement
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Management
rehabilitative physiotherapy
imaging guided injection of steroid or local anesthetic into area of focal capsular thickening or os trigonum synchondrosis
surgical treatmentarthroscopic resection of osseous abnormaluty and soft tissue abnormality with washout of joint
Posterior Impingement
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Posterior ankle ligament
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Posterior Impingement
Prominent lateral talar tubercle focal thickening of posterior capsule
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Posterior Impingement
focal thickening of posterior capsule adjacent to posterior talus (T)
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Posterior Impingement
BM edema within os trigonum
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Posterior Impingement
focal thickening of posterior capsule
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Posterior Impingement
Prominent os trigonum BM edema in posterior talus
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Posterior Impingement
limited plantar flexion BM edema in posterior talus and adjacent bone fragment
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Posterior Impingement
BM edema in posterior talus and adjacent bone fragmentfragmentation of lateral talar tubercle
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Posterior Impingement
BM edema in posterior talusInflammation of posterior recess of tibiotalar and subtalar jointIncomplete fracture with osteosclerosis