20059
Median follow - up was 1 . 5 years ( Range 0 . 9 to 4 . 3 years ) ; bone changes were annualized and compared to baseline .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None