Summary Sentence: Cementless solid tri-spiked titanium shells, with a polished inner surface and improved locking mechanism, demonstrated excellent fixation and survivorship at mid-term (minimum 5 years) follow-up.

Introduction: The tri-spiked Reflection cup (Smith & Nephew, Memphis) is a second-generation solid titanium shell with a polished inner surface, no screw holes and an improved locking mechanism. The purpose of this prospective study was to evaluate the minimum 5-year clinical & radiographic results and survivorship of this second-generation acetabular component.

Methods: Between 1997 and 2003, 659 primary THA were performed using the Reflection tri-spiked socket. None of the shells had adjuvant fixation with screws. The mean follow-up time was 7.0 years (5 to 11 yrs). The patients were followed prospectively using validated clinical outcome scores (WOMAC, SF-12, Harris Hip scores) and yearly radiographs.

Results: Twenty-seven patients had died before the minimum 5-year follow-up period. The mean Harris Hip and WOMAC scores were 89 and 79 respectively at last follow-up. Three sockets (0.6%) had been revised: two for infection, one for component malpositioning. No cup was revised for aseptic loosening. Six liners were exchanged: three for residual instability, 3 for wear associated with aseptic loosening of the stem. Radiographic review of remaining cups in-situ identified no cases of loosening and only a small number of cups (< 3%) with any osteolysis. The KM survivorship analysis with revision for any reason, was 97.5% and 97.4% at 5 and 10 years, while survivorship of the acetabular component was 99.8% at 5 and 10 years.

Conclusions: This second-generation cementless solid tri-spiked titanium shell, with a polished inner surface and improved locking mechanism, demonstrated excellent fixation and survivorship at mid-term follow-up.

The purpose of our study was to evaluate the initial results of this new technique of acetabular revision.

Osseointegration and cup stability were assessed by our musculoskeletal radiologist with radiographs at 2 years following surgery, and patients’ clinical outcomes were reviewed. We retrospectively reviewed the clinical records and radiographs of all patients who underwent acetabular revision between 2003 to 2005. Patient’s clinical outcomes and records were extracted from Orthowave and Statwave software. Radiographs were digitised and evaluated by our radiologist on E-film workstation.

Between January 2003 to May 2005, 62 consecutives patients with 65 acetabulum revisions (3 bilateral) were performed by a single surgeon. All acetabular shells were revised to revision tantalum shells with ancillary screws fixation. Fenestrated tantalum augments and wedges of different sizes and shapes were used to address bone defect in our series. 30.7% were Paprosky grade 3 and worse, 21.5% were Paprosky grade 2C. Radiologic review showed none of the cups had a change of 3° or more for cup inclination. There was no migration of the cups of 2 mm or greater both in the vertical direction and horizontal direction from our reference lines during the 2 year period. There were no new radiolucencies in any cases, and all the 9 cups with radiolucent lines post op either filled up or remain unchanged. Postoperative review mean HHS was 79.09 ± 16.16 (Range 33–100). There were 3 cases (4.6%) of dislocation. There were 9 fractures (13.9%) in our series.

In our series of 65 revisions, the porous tantalum revision system has performed well, despite being used to reconstruct fairly significant defects (Paprosky 2C and worse) in 52.3% of our cases. The clinical improvement, stability of the cup at 2 years, and acceptable complication rates would suggest that this porous tantalum system can be an alternative to a more traditional acetabular reconstruction.