Author investigated roentgenologically the posterior bone blocks of the ankle of 52 patients who had been treated by bone-block operations for sequellae of anterior poliomyelitis in our clinic.
Results obtained were as follows;
1) In the young group, the growth of the bone block was observed in many cases, but in adult it was in a few.
2) The pseudarthrosis of the bone block was occured in 6 cases, and it was caused by the too small or irregular shape of the bone block.
3) The remarkable resorption of the bone block was observed only in 1 case.
4) In the majority of cases, the ranges of motion of the ankle were between 10 to 20 degrees and the average plantar flexion was 103 degrees.
