Abstracto

The ostrigonum syndrome: A diagnosis not to be missed- A Review

Soukaina Allioui

The os trigonum is a triangular separate ossicle located at the posterior aspect of the talus close to the lateral tubercle. During plantarflexion, this ossicle and surrounding soft tissue become impinged between the posterior distal surface of the tibia and the superior surface of the calcaneus. The incidence of the os trigonum is 3 to 15%. Its bilateral form is more common than the unilateral one. This syndrome is found mostly in ballet dancers. Acute pain and swelling in the posterolateral aspect of the ankle are the characteristic elements of the os trigonum syndrome. Clinical examination findings can evok the possibility of this disease, but the diagnosis is confirmed by radiographs and Computed tomography showing the os trigonum. Magnetic resonance imaging may be used to rule soft tissue involvement. Initial treatment is conservative, when this later has failed to relieve the symptoms, surgical excision is indicated. The os trigonum syndrome refers to symptoms produced by pathology of the lateral tubercle of the posterior talar process. Pain can be caused by disruption of the cartilaginous synchondrosis between the os tnigonum and the lateral talar tubercle as a result of repetitive microtrauma and chronic inflammation. Additional etiologies include trigonal process fracture, flexor hallucis longus tenosynovitis, posterior tibiotalar impingement by bone block, and intraarticular loose bodies. This pictorial essay explores the role of imaging modalities in the diagnosis and treatment of the os trigonum syndrome, a symptom corn- plex that may present difficult diagnostic problems. The symptomatic os tnigonum has variously been named the os trigonum syndrome, talar compression syndrome, posterior ankle impingement syndrome, and posterior tibial talar impingement syndrome The symptoms of os trigo- num impingement include the chronic or the recurrent pain with stiffness, tenderness, and soft-tissue swelling in the posterior ankle. Strenuous activities that result in extreme plantar flexion such as ballet, soccer, football, and downhill running can cause compression of adjacent synovial and the capsular tissues against the posterior tibia. With repeated entrapment, the soft tissues tissues undergo inflammatory change with eventual thickening and fibrosis; associated flexor hallucis longus tenosynovitis may be present.