Comparison of Porous Tantalum Acetabular Implants and Harrington Reconstruction for Metastatic Disease of the Acetabulum

Abstract

Background: The periacetabular region is a common location for metastatic disease. Although large lytic acetabular defects are commonly treated with a hip arthroplasty with a cemented component according to a Harrington-style reconstruction, the use of highly porous uncemented tantalum acetabular components has been described. Currently, there are no direct comparisons of these reconstructive techniques. The purpose of this study was to compare the outcomes of the Harrington technique and tantalum acetabular component reconstruction for periacetabular metastases.

Methods: From 2 tertiary sarcoma centers, we retrospectively reviewed 115 patients (70 female and 45 male) with an acetabular metastatic defect who had been treated between 2002 and 2015 with a total hip arthroplasty using either the cemented Harrington technique (78 patients) or a tantalum acetabular reconstruction (37 patients). The mean patient age was 61 years, and the most common Eastern Cooperative Oncology Group status was 3 (39 patients). The mean follow-up for surviving patients was 4 years.

Results: An additional surgical procedure was performed in 24 patients (21%). Harrington-style reconstructions were more likely to require a reoperation compared with tantalum reconstructions (hazard ratio [HR], 4.59; p = 0.003). The acetabular component was revised in 13 patients (11%); 5 patients (4%) underwent revisions that were due to loosening of the acetabular component. The 10-year cumulative incidence of revision of the acetabular component for loosening was 9.6% in the Harrington group and 0% in the tantalum group (p = 0.09). The mean Harris hip score significantly improved following reconstruction (31 to 67 points; p < 0.001), with no significant difference (p = 0.29) between groups.

Conclusions: In patients with periacetabular metastatic disease treated with total hip arthroplasty, an acetabular reconstruction strategy utilizing highly porous tantalum acetabular components and augments successfully provided patients with a more durable construct with fewer complications compared with the cemented Harrington-style technique.

Levels of evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Fig. 1-A

Anteroposterior pelvic radiograph showing the pathologic fracture with pelvic discontinuity through a metastatic adenoid cystic carcinoma.

Fig. 1-B

Photograph showing intralesional curettage. Because of pain and the pathologic fracture, the patient underwent a complex total hip arthroplasty. Following exposure of the acetabulum, a large acetabular defect was noted and the area underwent intralesional curettage to remove all gross tumor.

Fig. 1-C

Photograph showing the defect filled with tantalum wedge augments and bone graft. After the intralesional curettage, the acetabulumwas reamed, and the defect was sized and was filled with tantalum wedge augments and bone graft.

Fig. 1-D

Photograph showing the construct, which was unitized with a bead of cement placed between the augments and the acetabular shell, which was impacted into place and was fixed with multiple screws.

Fig. 1-E

Photograph showing an over-the-top half-cage, which was also added to enhance fixation using screws through the cage and tantalum implant.

Fig. 1-F

Radiograph showing the cemented polyethylene and the placement of the femoral component.

Fig. 1-G

Positron emission tomography (PET) showing that the patient had diffuse disease progression and involvement around the hip.

Fig. 1-H

Anteroposterior radiograph showing that the implant remained well fixed.

Fig. 1-I

Lateral radiograph showing that the implant remained well fixed.

Fig. 2

Cumulative incidence of death due to disease and acetabular component loosening for aseptic causes in the Harrington reconstruction and tantalum groups. Although the 10-year rate of death due to disease was similar, patients who underwent a Harrington reconstruction were more likely to undergo a revision of the acetabular component due to loosening (p = 0.09).