Ankle Impingement Syndrome
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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
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Anterolateral Impingement
Anterior Impingement
Anteromedial Impingement
Posterior Impingement
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Posterior Impingement
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)
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Posterior Impingement
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
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Lateral talar tubercle
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Os trigonum
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Posterior Impingement
Clinical features
posterior ankle pain
exacerbated by plantar flexion or dorsiflexion
posterior tenderness
anterior to and not involving Axchilles tendon
palpable soft tissue thickening
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Posterior Impingement
Imaging features : Plain, CT, US
prominent lateral talar process or os trigonum
fracture not evident on plain radiography
symptomatic os trigonum :↑ activity
negative scan excludes this diagnosis
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Posterior Impingement
Imaging features : MRI
bone abnormality
bone marrow edema in lateral talar tubercle or os trigonum
fracture line or fluid in synchondrosis (os trigonum fracture)
posterior capsular or ligament thickening
low to intermediate SI on T2-WI
Synovitis
posterior synovial recess of subtalar and tibiotalar joint
FHL tendon sheath
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Posterior Impingement
Management
rehabilitative physiotherapy
imaging guided injection of steroid or local anesthetic
into area of focal capsular thickening or os trigonum
synchondrosis
surgical treatment
arthroscopic resection of osseous abnormaluty and
soft tissue abnormality with washout of joint
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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 fragment
fragmentation of lateral talar tubercle
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Posterior Impingement
BM edema in posterior talus
Inflammation of posterior recess of
tibiotalar and subtalar joint
Incomplete fracture with osteosclerosis
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