Published online Jul 18, 2017. doi: 10.5312/wjo.v8.i7.553
Peer-review started: February 12, 2017
First decision: April 18, 2017
Revised: May 15, 2017
Accepted: May 30, 2017
Article in press: May 31, 2017
Published online: July 18, 2017
To evaluate the clinical and X-ray results of acetabular components and tantalum augments in prosthetic hip revisions.
Fifty-eight hip prostheses with primary failure of the acetabular component were reviewed with tantalum implants. The clinical records and X-rays of these cases were retrospectively reviewed. Bone defect evaluations were based on preoperative CT scans and classified according to Paprosky criteria of Radiolucent lines and periprosthetic gaps; implant mobilization and osteolysis were evaluated by X-ray. An ad hoc database was created and statistical analyses were performed with SPSS software (IBM SPSS Statistics for Windows, version 23.0). Statistical analyses were carried out using the Student’s t test for independent and paired samples. A P value of < 0.05 was considered statistically significant and cumulative survival was calculated by the Kaplan-Meier method.
The mean follow-up was 87.6 ± 25.6 mo (range 3-120 mo). 25 cases (43.1%) were classified as minor defects, and 33 cases (56.9%) as major defects. The preoperative HHS rating improved significantly from a mean of 40.7 ± 6.1 (range: 29-53) before revision, to a mean of 85.8 ± 6.1 (range: 70-94) at the end of the follow-up (Student’s t test for paired samples: P < 0.001). Considering HHS only at the end of follow-up, no statistically significant difference was observed between patients with a major or minor defect (Student’s t test for independent samples: P > 0.05). Radiolucent lines were found in 4 implants (6.9%). Postoperative acetabular gaps were observed in 5 hips (8.6%). No signs of implant mobilization or areas of periprosthetic osteolysis were found in the x-rays at the final follow-up. Only 3 implants failed: 1 case of infection and 2 cases of instability. Defined as the end-point, cumulative survival at 10 years was 95% (for all reasons) and 100% for aseptic loosening of the acetabular component.
The medium-term use of prosthetic tantalum components in prosthetic hip revisions is safe and effective in a wide variety of acetabular bone defects.
Core tip: Revisions of acetabular implant components are frequently associated with bone defects. Porous tantalum acetabular cups and augments were introduced to improve biological fixing and restore the normal centre of rotation. The greatest advantage is for major bone defects, where the tantalum cup and augments provide stable primary fixing with the biological potential for bone ingrowth. Nowadays, porous tantalum represents the ideal bone substitute in prosthetic revisions.