The median time to pain-free full weight-bearing was also not significantly different among the SOC ( 13.4 weeks ) , 1.0-mg / mL rhBMP-2 / CPM ( 13.4 weeks ) , 2.0-mg / mL rhBMP-2 / CPM ( 14.3 weeks ) , and buffer/CPM ( 16.4 weeks ) treatment groups .