Extensile Direct Anterior Approach to the Hip for Severe Acetabular Defects

Although total hip arthroplasty (THA) surgery is one of the most successful procedures in orthopaedics, the number of revision procedures is predicted to increase by 137% over the next two decades.¹ Implant failure modes such as instability, infection, loosening, and wear are becoming more prevalent.² Instability, infection, extensive bony defects, and soft-tissue damage are the most important concerns and complications associated with revision surgery. More than 50% of revisions involve the acetabular implant.² Paprosky et al described a classification of acetabular defects that occur in cases of implant failure.³ Treating type 2 and 3 uncontained defects can be technically challenging because the surgeon has to use extensive reconstruction techniques to adequately restore the biomechanics of the hip, structural stability, and leg length. Furthermore, neurovascular structures can be in jeopardy when complex pelvic reconstructive procedures are being conducted. In an attempt to optimize the access to the pelvic bone, to minimize soft-tissue damage and to protect the pelvic neurovascular structures, we use an extensile anterior approach to the acetabulum. This approach has been described by Ganz et al to conduct periacetabular osteotomies (PAO).^4,5 This approach uses the Smith Petersen interval and exposes the anterior column and the acetabulum along with its defects. To our knowledge, the approach has not been used or described yet to conduct complex reconstructive surgeries for extensive acetabular defects in THA. The following is a description of a modified extensile surgical technique for challenging acetabular defects that may be encountered in certain revision THA reconstructions, as well as certain primary THA. This is an enhanced technical description of a technique presented by these authors in a previously described series of 48 patients who underwent revision using these techniques.⁶.