POSTERIOR IMPINGEMENT SYNDROME :
A CASE REPORT
J. BEN HAFDHALLAH, S. BOURKHIS, F. SNENE, M.A.GHODHBANI,
H. RAJHI, N. MNIF. CHARLE NICOLLE’S HOSPITAL, TUNIS,
TUNISIA.
MK6
OBJECTIVES
Evaluate the role of
imaging modalities
in the
diagnosis and management of the posterior tibio
talian
syndrome.
It
includes
clinical
situations
secondary to entrapment of bony elements or soft
tissue between the posterior edge of the tibia and
calcaneus during plantar flexion of the ankle.
A CASE REPORT
This is a 27-year-old male who
posterior
ankle
pain
usually complains of
exacerbated
by plantar
flexion or dorsiflexion . An Achille tendinopathy was
firstly suspected.
RESULTS
AN ULTRASOUND EXAM OF ACHILLE TENDON
Right anlke / axial plane
Tibio talian intra articular liquid
RESULTS
Lateral ankle radiographs
Lateral
ankle
radiograph
shows
a
prominent
posterior process of the
tibia and a long posterior
talian process .
MR imaging
RESULTS
Sagittal (T2 / T1-weighted) and axial (T1-weighted) MR image shows
focal thickening of posterior pericapsular tissue ( ) but normal bone
marrow signal intensity in the postérior process. Note the tibio talian
intra articular liquid (
).
TREATMENT
RESULTS
A posterior tibio talian syndrome was diagnosed. The
patient had an arthroscopic treatement with supression
of prominent posterior process. Clinical evolution marked
by an improvement.
Lateral ankle radiograph before and after surgery shows a
disappearance of prominent posterior process (
).
DISCUSSION
 Posterior impingement has been described under a
variety of different names, including os trigonum
syndrome and posterior tibiotalar compression
syndrome.
 The condition arises from compression of the soft
tissues between the posterior process of the talus
and the posterior tibia on plantar flexion of the
ankle.
DISCUSSION
CAUSES
The syndrome can develop after
 a significant acute injury:
avulsion of the posterior talo-fibular ligament.
 talar fracture.
 disruption of an os trigonum.

 A chronic injury:
 a repetitive forced plantar flexion of the foot(ballet
dancers).
DISCUSSION
CLINICAL FEATURES
 The syndrome usually manifests clinically when a
significant soft-tissue component forms.
 Clinical symptoms usually consist of posterior ankle
pain exacerbated by plantar flexion or dorsiflexion.
 Clinical examination shows:
 Posterior tenderness anterior to and not involving
the Achilles tendon.
 Occasionally, palpable soft-tissue thickening
DISCUSSION
IMAGING FEATURES
CONVENTIONAL RADIOGRAPHS
 Conventional radiographs may show a
prominent lateral talar process or os
trigonum.
DISCUSSION
IMAGING FEATURES
US exam

Ultrasound is a useful technique for
accurate real-time guidance of therapeutic
injection.
IMAGING FEATURES
DISCUSSION
MR imaging
 MR imaging shows:
 Bone marrow edema.
 A fracture line.
 fluid in the synchondrosis.
 Posterior capsular or ligament thickening with
intermediate to low signal intensity on T2-weighted
images.
IMAGING FEATURES
DISCUSSION
MR imaging
 The integrity of the ligaments.
 Possible associated flexor hallucis longus abnormality or
other internal derangement, which can alter any planned
surgical approach.
 Enhancement after intravenous administration of
gadolinium contrast material can highlight small focal
areas of synovitis.
IMAGING FEATURES
DISCUSSION
Management
 Imaging-guided injection (a steroid or local anesthetic):
Most cases of posterior impingement of the ankle
respond to conservative treatment (physiotherapy).
 Surgery: in resistant cases.
CONCLUSION
 Impingement syndromes of the ankle are usually
a clinical diagnosis.
 Conventional radiograph plays an important role in the
initial assessment of these conditions.

MR imaging is most useful in posterior impingement,
where it can identify the relative contributions of the
osseous and soft-tissu components.