504
In passive hinge system , the ACA is fixed on the frame in Ilizarov system or on the convex side of corticotomy in unilateral fixator system , and angular correction is achieved by changing the length of the motor ( Ilizarov system ) or the lengthener ( unilateral fixator ) which rotates the passive hinge .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Anatomy 
Text: {0} 
Answer:
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