Fig. 1

Oblique image intensifier views to prevent dissection of the posterior column and intra-articular osteotomy during curved periacetabular osteotomy. (a) The ischium of the posterior column is osteotomised from the innominate grooves using a curved chisel. (b) The ilium of the posterior column is osteotomised from the arcuate line using a curved chisel. The solid white lines indicate the joint line of the acetabulum, and the dashed white lines indicate the posterior border of the posterior column.