INDICATIONS FOR INTERTROCHANTERIC OSTEOTOMY AFTER PERIACETABULAR OSTEOTOMY FOR ADULT HIP-DYSPLASIA

Residual hip dysplasia in the adult is characterized by deficient ante rior and lateral acetabular coverage with subsequent hip joint incongr uity and instability, The frequency of periacetabular osteotomy for th e treatment of residual hip dysplasia is increasing, In certain morpho logic conditions preoperative abduction or intraoperative radiographs reveal that congruency after a periacetabular osteotomy is not optimum ; at this point the surgeon may consider the addition of an intertroch anteric osteotomy, In a retrospective study, the radiographs of 25 pat ients who had a femoral osteotomy with or after periacetabular osteoto my were analyzed and the results were compared with a control group of 34 patients who had periacetabular osteotomy without a femoral osteot omy, The analyzed parameters included: the femoral head extrusion inde x and the acetabular index, before and after periacetabular osteotomy; the femoral neck shaft angle; the presence of femoral head deformity; the presence of osteoarthrosis; the presence of a secondary acetabulu m; the influence of previous ipsilateral hip surgery; the effect of hi p adduction or abduction on Joint congruency; and the age of the patie nt, The variables that had a statistically significant association wit h the performance of an intertrochanteric osteotomy included a femoral head extrusion index and an acetabular index after periacetabular ost eotomy outside the normal limits, a neck shaft angle outside the limit s of the control group, a deformed femoral head, an osteoarthritic hip , a secondary acetabulum, and a joint space height and congruency depe ndent on position of the proximal femur, When using statistically sign ificant variables, a discriminant analysis predicted the correct group (periacetabular osteotomy with femoral osteotomy, or periacetabular o steotomy without femoral osteotomy) for 89% of the cases.