Bridging Massive Acetabular Defects With the Triflange Cup: 10- to 28-Year Results

Pelvic Reconstruction for Complex Bone Defects in Revision Total Hip Arthroplasty

Pelvic bone loss in the setting of total hip arthroplasty (THA) creates a challenge for reconstructing the acetabulum during revision THA. The complexity of managing acetabular bone loss lies in its highly variable presentation, ranging from minor osteolytic defects to extensive segmental and cavitary deficiencies. This article will highlight treatment options for complex pelvic defects (Paprosky 3A/3B) and frequently associated pathology, such as instability and infection.

Custom Acetabular Components in Revision Total Hip Arthroplasty: A Systematic Review

INTRODUCTION

Custom acetabular components (CACs) have demonstrated promising results in revision total hip arthroplasties (THAs) with substantial acetabular bone loss. However, previous systematic reviews are limited by short follow-up. The purpose of this systematic review was to report midterm outcomes of CACs in revision THAs.

METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. We searched MEDLINE, EMBASE, Cochrane Databases, and Scopus databases for English publications with a minimum 2-year follow-up. There were 14 studies that met the inclusion criteria, with 592 CACs available for re-revision and implant removal analysis and 603 available for reoperation analysis. The mean age was 63 years, the mean BMI was 29, and 68% were women. The mean follow-up was seven years.

RESULTS

The CAC re-revision rate was 19 per 1,000 person-years of follow-up (n = 84), the all-cause re-revision rate was 21 per 1,000 person-years (n = 93), and the CAC removal rate was eight per 1,000 person-years (n = 36). The most common indications for CAC re-revision included dislocation (n = 31), periprosthetic joint infection (PJI, n = 30), and CAC aseptic loosening (n = 12). The indications for CAC removal included PJI (n = 22), aseptic loosening (n = 12), and dislocation (n = 2). In addition to the 93 re-revisions, there were 37 reoperations (28 per 1,000 person-years). The mean Harris Hip Score improved from 38 to 75 at final follow-up.

CONCLUSION

In this systematic review including over 600 CACs, the re-revision rate was 19 per 1,000 person-years, but 94% of CACs were retained at a mean of seven years of follow-up. Considering the complexity of these cases, CACs have acceptable survivorship. Dislocation and PJI contributed to the high re-revision rate, while PJI and aseptic loosening were the most common reasons for implant removal.

LEVEL OF EVIDENCE

Level IV, Systematic Review of Case Series.

AAHKS Surgical Techniques & Technologies Award: Inferior Screw Fixation Decreases Acetabular Component Failure Following Revision Total Hip Arthroplasty

BACKGROUND

Adjunctive screw fixation has been shown to be reliable in achieving acetabular component stability in revision total hip arthroplasty (THA). The purpose of this study was to assess the effect of inferior screw placement on acetabular component failure following revision THA. We hypothesized that inferior screw fixation would decrease acetabular failure rates.

METHODS

We reviewed 250 patients who had Paprosky Type II or III defects who underwent acetabular revision between 2001 and 2021 across three institutions. Demographic factors, the number of screws, location of screw placement (superior versus inferior), use of augments and/or cup-cage constructs, Paprosky classification, and presence of discontinuity were documented. Multivariate regression was performed to identify the independent effect of inferior screw fixation on the primary outcome of aseptic rerevision of the acetabular component.

RESULTS

At a mean follow-up of 53.4 months (range, 12 to 261), 16 patients (6.4%) required re-revision for acetabular loosening. There were 140 patients (56.0%) who had inferior screw fixation, all of whom did not have neurovascular complications during screw placement. Patients who had inferior screws had a lower rate of acetabular rerevision than those who only had superior screw fixation (2.1 versus 11.8%, P = .0030). Multivariate regression demonstrates that inferior screw fixation decreased the likelihood of rerevision for acetabular loosening when compared to superior screw fixation alone (odds ratio: 0.1, confidence interval: 0.03 to 0.5; P = .0071). No other risk factors were identified.

CONCLUSIONS

Inferior screw fixation is a safe and reliable technique to reduce acetabular component failure following revision THA in cases of severe acetabular bone loss.

Evaluation and Management of Acetabular Bone Loss in Revision Total Hip Arthroplasty: A 10-year Update

Acetabular bone loss continues to be one of the most complex and challenging scenarios facing the orthopaedic surgeon. Preoperative planning and classification systems essentially have remained the same, with the Paprosky classification still being the most commonly used. Careful radiological assessment with well-defined criteria can accurately diagnose acetabular bone loss patterns with an associated chronic pelvic discontinuity before surgery. The use of cemented reconstruction techniques has declined, and contemporary practice trends have involved the increasing use of highly porous hemispherical shells in conjunction with modular porous metal augments, which can successfully treat most acetabular revisions. Noncemented treatment options for the management of acetabular bone loss during revision include conventional porous/modular highly porous hemispherical implants, nonmodular highly porous implants with cementable acetabular liners, cup-cage reconstruction, oblong cups, and triflange reconstruction. These options can be combined with modular porous metal augments, structural allografts, impaction grafting, or reconstruction cages. Acetabular distraction is a newer technique for chronic pelvic discontinuity, which is used in conjunction with off-the-shelf revision acetabular shells and modular porous metal augments. This review is an update over the past decade, highlighting studies with mid to long-term follow-up, and presents the advantages, disadvantages, and principles associated with each of the most commonly used reconstructive techniques.