Acetabular reconstruction in revision total hip arthroplasty.

The number of total hip arthroplasty (THA) procedures performed annually continues to rise. Specific challenges, including acetabular bone loss, are commonly encountered at the time of revision surgery, and orthopaedic surgeons must be prepared to address them. This review focuses on topics related to acetabular reconstruction, including pre-operative patient evaluation (clinical and radiographic), pre-operative planning, common causes of acetabular failure, classification of acetabular bone loss, methods of acetabular reconstruction, and clinical results based on reconstruction method. Pre-operative patient evaluation for revision THA begins with a thorough history and physical examination as well as laboratory workup to rule out infection. Detailed radiographic evaluation and pre-operative planning are also essential and will facilitate communication amongst all members of the operative team. Although there are several ways to describe acetabular bone loss, the Paprosky classification system - defined by anterosuperior and posteroinferior acetabular column integrity - is the system most commonly used today and will guide treatment strategy. Several treatment strategies have been developed and may be termed either "cemented" (e.g. impaction grafting, ring and cage construction, structural allograft) or "uncemented" (e.g. hemispheric shell ± porous metal augment, cup-cage, custom triflange acetabular component). Although each strategy has its advantages and disadvantages, the general principles remain the same. Successful treatment depends upon detailed pre-operative assessment, planning, and team-based plan execution. Uncemented techniques that allow for biologic fixation are preferred. In the special case of pelvic discontinuity, acetabular distraction is the authors' preferred technique. Longer term studies are still needed to evaluate the longevity of each of the various reconstruction methods presented.