Surgical hip dislocation and varus derotation osteotomy for extra-articular cause of femoroacetabular impingement: a single case report

Femoral retroversion is an extra-articular cause of cam-type femoroacetabular impingement (FAI) via early engagement with anterior rim. Valgus hip also causes extra-articular FAI by decreasing the range of motion. We present a case of valgus hip accompanied by femoral retroversion, which was refractory to prior arthroscopic femoroplasty. As a reasonable strategy, we have performed extra-articular correction via femoral subtrochanteric varus derotation osteotomy as well as intra-articular decompression by surgical hip dislocation. Femoral varus derotation osteotomy with surgical hip dislocation is a rational and appropriate solution in patients with extra-articular FAI, which is refractory to arthroscopic FAI surgery. Extra-articular causes of FAI should be suspected in every refractory case.