Acetabular Bone Loss in Revision Total Hip Arthroplasty: Evaluation and Management

Abstract

As the number of primary total hip arthroplasty (THA) procedures performed continues to rise, the burden of revision THA procedures is also expected to increase. Proper evaluation and management of acetabular bone loss at the time of revision surgery will be an increasing challenge facing orthopaedic surgeons. Proper preoperative patient assessment and detailed preoperative planning are essential in obtaining a good clinical result. Appropriate radiographs are critical in assessing acetabular bone loss, and specific classification schemes can identify bone loss patterns and guide available treatment options. Treatment options include impaction grafting and cementation of the acetabulum, noncemented hemispheric acetabular reconstruction, structural allograft reconstruction, noncemented reconstruction with modular porous metal augments, ring and cage reconstruction, oblong cup reconstruction, cup-cage reconstruction, and triflange reconstruction.

Classifications In Brief: Paprosky Classification of Acetabular Bone Loss

“…The Paprosky classification is based on the amount of hip center migration and the integrity of four acetabular supporting structures as evaluated on preoperative AP radiographs of the pelvis [11,14] ( Fig. 2; Table 1).…”

“…The acetabular rim is deficient from 9 o'clock to 5 o'clock, representing greater then 60% destruction of the supporting bone stock. Although the original description denotes hip center migration as more or less than 2 cm [11], a more recent publication liberalizes this migration to less than or greater than 3 cm [14].…”

Analysis of the Results of Use of Bone Graft and Reconstruction Cages in a Group of Patients with Severe Acetabular Bone Defects

“…A reinforcement cage is designed to manage extended pelvic defects by bridging large bone gaps and protecting the grafts filled to increase the bone stock in case of future revision [6]. The major advantage of rings and cages is the ability to cement a liner in any position independent of the cage position and the elution of local antibiotics from the cement [2]. The lack of bony ingrowth and biological fixation exposed them to cyclical loading resulting in failure of hardware, typically screw breakage or migration of the ischial flange [8,13,16], with this being their major disadvantage.…”

“…The most common indications for acetabular revision include hip instability, aseptic loosening, periprosthetic osteolysis, and infection [2,3], with the acetabular component involved in >50% of revisions [3]. Acetabular bone loss can be found in any of the revisions of THA and is one of the factors to be taken into account when determining treatment.…”

“…Consequently, the demand for revision total hip arthroplasty will also increase exponentially. It is estimated that total hip arthroplasty revisions will double every 10 years [2].…”