Total hip arthroplasty in patients with proximal femoral deformity

Most proximal femoral deformities encountered during hip arthroplasty are s econdary to developmental processes, previous osteotomy, or fracture. A cla ssification method is proposed in which deformities are categorized anatomi cally by level. Anatomic deformity levels include: greater trochanteric def ormities, femoral neck deformities, metaphyseal level deformities, and diap hyseal level deformities. Deformities at each level may be angular, rotatio nal or translational, abnormal bone size, or a combination thereof. Treatme nt is individualized according to patient needs and the anatomy of the defo rmity. Careful preoperative planning helps predict prosthesis requirements and technical challenges. If cemented implants are used, care must he taken to obtain reasonable alignment and a continuous cement mantle. For uncemen ted implants, obtaining a good fit is challenging and there is a risk of in traoperative fracture. Access to a wide range of implants helps the surgeon treat unique femoral geometries. Implants fixed in the diaphysis allow som e proximal femoral deformities to be bypassed. Modular or custom implants s implify treatment of certain deformities. For patients with severe deformit ies, femoral osteotomy may be required. Successful osteotomy requires corre cting the deformity, maintaining vascular supply of fragments, obtaining fi xation of osteotomy fragments (with the implant or adjunctive fixation), an d obtaining implant stability. Although most deformities can be treated dur ing hip arthroplasty, occasionally there is a role for two-stage treatment: deformity correction followed later by arthroplasty.