POSTERIOR IMPINGEMENT SYNDROME : A CASE REPORT

1. J. BEN HAFDHALLAH, S. BOURKHIS, F. SNENE, M.A.GHODHBANI, H. RAJHI, N. MNIF. CHARLE NICOLLE’S HOSPITAL, TUNIS, TUNISIA. POSTERIOR IMPINGEMENT SYNDROME :A CASE REPORT MK6

2. OBJECTIVES Evaluate the role of imaging modalities in the diagnosis and management of the posterior tibiotalian 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.

3. A CASE REPORT This is a 27-year-old male who usually complains of posterior ankle pain exacerbated by plantar flexion or dorsiflexion. An Achilletendinopathy was firstly suspected.

4. RESULTS • AN ULTRASOUND EXAM OF ACHILLE TENDON Right anlke / axial plane Tibiotalian intra articular liquid

5. RESULTS Lateral ankle radiographs Lateral ankle radiograph shows a prominent posterior process of the tibia and a long posterior talian process .

6. RESULTS MR imaging 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 postériorprocess. Note the tibiotalian intra articular liquid ( ).

7. RESULTS TREATMENT A posterior tibiotalian syndromewasdiagnosed. The patient had an arthroscopictreatementwithsupression of prominent posterior process. Clinical evolution marked by an improvement. Lateral ankle radiograph before and after surgery shows a disappearance of prominent posterior process ( ).

8. DISCUSSION • Posterior impingement has been described under a variety of different names, including ostrigonumsyndrome 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.

9. DISCUSSION CAUSES The syndrome can develop after • a significant acute injury: • avulsion of the posterior talo-fibular ligament. • talar fracture. • disruption of an ostrigonum. • A chronic injury: • a repetitiveforced plantar flexion of the foot(ballet dancers).

10. DISCUSSION CLINICAL FEATURES • The syndrome usuallymanifestsclinically when a significant soft-tissue component forms. • Clinicalsymptomsusually consist of posterior ankle pain exacerbated by plantar flexion or dorsiflexion. • Clinicalexamination shows: • Posterior tenderness anterior to and not involving the Achilles tendon. • Occasionally, palpable soft-tissue thickening

11. DISCUSSION CONVENTIONAL RADIOGRAPHS IMAGING FEATURES • Conventional radiographs may show a prominent lateraltalarprocess or os trigonum.

12. DISCUSSION US exam IMAGING FEATURES • Ultrasound is a useful technique for accurate real-time guidance of therapeutic injection.

13. DISCUSSION IMAGING FEATURES MR imaging • MR imaging shows: • Bonemarrow edema. • A fracture line. • fluid in the synchondrosis. • Posteriorcapsular or ligament thickening with intermediate to low signal intensity on T2-weighted images.

14. DISCUSSION IMAGING FEATURES MR imaging • The integrity of the ligaments. • Possible associatedflexor hallucislongus abnormality or other internal derangement, which can alter any planned surgicalapproach. • Enhancementafterintravenousadministration of gadolinium contrast material can highlight small focal areas of synovitis.

15. DISCUSSION IMAGING FEATURES 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.

16. CONCLUSION • Impingement syndromes of the ankle are usually a clinical diagnosis. • Conventionalradiographplays 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-tissucomponents.