Weekly Case

Title : Case 21

첨부파일 : posterior_ankle_impingement_syndrome.ppt

Age / Sex : 11 / F


C.C.: posterior ankle pain exacerbated by plantar flexion or dorsiflexion 





1) What is your impression?

Courtesy : Kil Ho Cho, MD., Yeungnam University College of Medicine


Diagnosis:

Os trigonum SD



Discussion


Findings:
- a well defined os trigonum on plain radiography
- bone marrow edema in the os trigonum and the adjacent posterior talus on MR images

Differential Diagnosis:
- Os trigonum syndrome * synonyms: posterior impingement syndrome, talar compression syndrome
- fracture of lateral tubercle of talus (Shepherd's fracture)

Diagnosis: Os trigonum syndrome (posterior impingement syndrome)

Discussion:
1) occurs when the trigonal process of the talus or the os trigonum is compressed between the posterior tibia and the posterior calcaneus during forced plantar flexion
2) Clinical features - posterior ankle pain : exacerbated by plantar flexion or dorsiflexion - posterior tenderness : anterior to and not involving Axchilles tendon - palpable soft tissue thickening
3) 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
4) Imaging features : MRI - BM edema in lateral talar tubercle or os trigonum - fracture line or fluid in synchondrosis (os trigonum fracture) - posterior capsular or ligament thickening - Synovitis : posterior synovial recess of subtalar and tibiotalar joint FHL tendon sheath
5) Management a) rehabilitative physiotherapy b) imaging guided injection of steroid or local anesthetic into area of focal capsular thickening or os trigonum synchondrosis c) surgical treatment - arthroscopic resection of osseous abnormaluty and soft tissue abnormality with washout of joint

References:
1. Nathalie J. Bureau, Étienne Cardinal, Roger Hobden, and Benoit Aubin. Posterior Ankle Impingement Syndrome: MR Imaging Findings in Seven Patients Radiology 2000; 215:497-503



Correct Answer
Name Institution
성미숙 (정답) : 가톨릭의대
이민희 (정답) : 강북 삼성병원
김완태 (정답) : 서울 보훈병원
황지영 (정답) : 이대목동병원
조용수 (정답) : 여수백병원
오배근 (정답) : 일산백병원 전공의
박소영 (정답) : 경희의료원 전공의
심수연 (정답) : 경희의료원 전공의
강수진 (감별진단 정답) : 삼천포 제일병원

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