Conventional Magnetic Resonance Imaging Versus Magnetic Resonance Arthrography in Evaluation of Ankle Impingement Syndromes and Intra Articular Pathologies.

The anterolateral impingement syndrome is caused by obstruction of the so-called anterolateral gutter (ALG) or recess secondary to an inversion injury resulting in disruption of the syndesmotic and/or lateral collateral ligaments and capsule.

In anterior impingement,Arthroscopic evaluations suggest direct microtrauma to the talus and tibia as the aetiology. The natural course of this microtraumas to form osseous spurs.

In anteromedial impingement,The mechanism is not well understood but is likely a rare complication of a supination (inversion) injury rather than a pronation (eversion) injury as initially hypothesized.During the acute injury, there is damage to the anterior tibiotalar ligament, which subsequently thickens. In addition toligament thickening, osteophytes, synovitis and fractures have been described as other possible causative factors.

In posteromedial impingement, the common precipitating injury for posteromedial ankle impingement is a plantar flexion, inversion and internal rotation trauma. This can lead to damage to the PTTL and associated synovitis.

The majority of the posterior impingement syndromes are related to the posterior talus.The secondary ossification centre of the posterolateral talus forms around 8-13 years of age and then subsequently fuses within 1 year of that. Occasionally (approximately 7%), there may be non-fusion with a resultant ostrigonum.