{"id":24376,"date":"2025-05-21T08:16:53","date_gmt":"2025-05-21T08:16:53","guid":{"rendered":"https:\/\/utkuerdemozer.com\/os-trigonum-syndrome\/"},"modified":"2026-03-11T23:29:53","modified_gmt":"2026-03-11T20:29:53","slug":"os-trigonum-syndrome","status":"publish","type":"post","link":"https:\/\/www.utkuerdemozer.com\/en\/os-trigonum-syndrome\/","title":{"rendered":"Os Trigonum Syndrome (Posterior Ankle Impingement Syndrome)"},"content":{"rendered":"

Os trigonum syndrome, also known as <\/span>posterior ankle impingement syndrome<\/span><\/strong>, is characterized by pain in the back of the ankle. This condition is caused by the impingement of an accessory bone called the\u00a0<\/span>os trigonum<\/span><\/em>\u00a0and the posterior talar process, leading to inflammation in the rear ankle region. It is commonly associated with pain at the back of the ankle and difficulty with toe-pointing movements.<\/span><\/p>\n

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Os trigonum syndrome is more frequently seen in\u00a0<\/span>ballet dancers, male ballet dancers, and football players<\/span><\/strong>, due to the repetitive ankle movements and hyperplantarflexion involved in their activities.<\/span><\/span><\/p>\n<\/div>\n

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The\u00a0<\/span>first-line treatment<\/span><\/strong>\u00a0for os trigonum syndrome includes\u00a0<\/span>rest, physical therapy, and ultrasound-guided <\/span><\/strong>corticosteroid injections<\/u><\/span><\/strong><\/a>, which are often effective in relieving symptoms.<\/span><\/span><\/p>\n<\/div>\n

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In cases where non-surgical treatments fail,\u00a0<\/span>arthroscopic (minimally invasive) surgery<\/span><\/strong>\u00a0can be performed successfully to treat os trigonum syndrome by removing the impinging bone fragment.<\/span><\/span><\/p>\n<\/div>\n

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What Is the Os Trigonum?<\/span><\/strong><\/span><\/h2>\n<\/div>\n
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The\u00a0<\/span>os trigonum<\/span><\/strong>\u00a0is the\u00a0<\/span>second most common accessory bone<\/span><\/strong>\u00a0found in the human body. It is present in approximately\u00a0<\/span>20% of the population<\/span><\/strong>\u00a0and is located at the\u00a0<\/span>back of the ankle joint<\/span><\/strong>.<\/span><\/span><\/p>\n<\/div>\n

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Where Is the Os Trigonum Bone Located?<\/span><\/strong><\/span><\/h2>\n<\/div>\n
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The os trigonum is a\u00a0<\/span>small, extra bone<\/span><\/strong>\u00a0situated at the\u00a0<\/span>rear of the ankle joint<\/span><\/strong>, behind the talus bone. It develops when a secondary ossification center of the talus fails to fuse completely during skeletal growth.<\/span><\/span><\/p>\n<\/div>\n

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Not everyone has this bone. However, when it is present, it is often found\u00a0<\/span>symmetrically in both ankles<\/span><\/strong>.<\/span><\/span><\/p>\n<\/div>\n

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In most cases, the presence of an os trigonum does\u00a0<\/span>not cause any problems<\/span><\/strong>, and many people remain unaware that they even have it.<\/span><\/span><\/p>\n<\/div>\n

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What Is Os Trigonum Syndrome?<\/span><\/strong><\/span><\/h2>\n<\/div>\n
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Os trigonum syndrome<\/span><\/strong>\u00a0is a condition characterized by\u00a0<\/span>pain at the back of the ankle<\/span><\/strong>. Not every person with an os trigonum develops symptoms. The condition typically arises after\u00a0<\/span>long periods of repetitive ankle movements<\/span><\/strong>, especially in athletes. In some cases, it can be triggered by\u00a0<\/span>a single traumatic event<\/span><\/strong>, such as landing on the toes from a height.<\/span><\/span><\/p>\n<\/div>\n

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In athletes like football players who forcefully bend the ankle while kicking the ball, or in ballet dancers who frequently rise en pointe, the os trigonum can become\u00a0<\/span>compressed between the bones<\/span><\/strong>, leading to pain. Swimmers using the\u00a0<\/span>butterfly stroke<\/span><\/strong>\u00a0may also experience symptoms due to repeated\u00a0<\/span>forced plantar flexion<\/span><\/strong>\u00a0of the ankle to reduce water resistance.<\/span><\/span><\/p>\n<\/div>\n

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It\u2019s important to note that not all posterior ankle impingement is caused by the os trigonum. Sometimes, an elongated\u00a0<\/span>posterior talar process<\/span><\/strong>\u00a0(a bony projection at the back of the talus) can also lead to impingement and pain.<\/span><\/span><\/p>\n<\/div>\n

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Common Characteristics of Athletes With Os Trigonum Syndrome<\/span><\/strong><\/span><\/p>\n<\/div>\n

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